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  1. Cancer testis antigen vaccination affords long-term protection in a murine model of ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Maurizio Chiriva-Internati

    Full Text Available Sperm protein (Sp17 is an attractive target for ovarian cancer (OC vaccines because of its over-expression in primary as well as in metastatic lesions, at all stages of the disease. Our studies suggest that a Sp17-based vaccine can induce an enduring defense against OC development in C57BL/6 mice with ID8 cells, following prophylactic and therapeutic treatments. This is the first time that a mouse counterpart of a cancer testis antigen (Sp17 was shown to be expressed in an OC mouse model, and that vaccination against this antigen significantly controlled tumor growth. Our study shows that the CpG-adjuvated Sp17 vaccine overcomes the issue of immunologic tolerance, the major barrier to the development of effective immunotherapy for OC. Furthermore, this study provides a better understanding of OC biology by showing that Th-17 cells activation and contemporary immunosuppressive T-reg cells inhibition is required for vaccine efficacy. Taken together, these results indicate that prophylactic and therapeutic vaccinations can induce long-standing protection against OC and delay tumor growth, suggesting that this strategy may provide additional treatments of human OC and the prevention of disease onset in women with a family history of OC.

  2. Cancer vaccine--Antigenics.

    Science.gov (United States)

    2002-01-01

    Antigenics is developing a therapeutic cancer vaccine based on heat-shock proteins (HSPs). The vaccine [HSPPC-96, Oncophage] is in a pivotal phase III clinical trial for renal cancer at 80 clinical sites worldwide. The trial is enrolling at least 500 patients who are randomised to receive surgical removal of the primary tumour followed by out-patient treatment with Oncophage((R)) or surgery only. This study was initiated on the basis of results from a pilot phase I/II study and preliminary results from a phase II study in patients with renal cell cancer. In October 2001, Oncophage was designated as a fast-track product by the Food and Drug Administration in the US for the treatment of renal cell carcinoma. Oncophage is in phase I/II trials in Italy for colorectal cancer (30 patients) and melanoma. The trials in Italy are being conducted at the Istituto dei Tumouri, Milan (in association with Sigma-Tau). Preliminary data from the phase II trial for melanoma was presented at the AACR-NCI-EORTC International Conference in Florida, USA, in October 2001. Oncophage is also in a phase I/II (42 patients) and a phase II trial (84 patients) in the US for renal cell cancer, a phase II trial in the US for non-Hodgkin's lymphoma (35 patients), a phase II trial in the US for sarcoma (20-35 patients), a phase I/II trial in the US for melanoma (36 patients), and phase I/II trials in Germany for gastric (30 patients) and pancreatic cancers. A pilot phase I trial in patients with pancreatic cancer began in the US in 1997 with 5 patients enrolled. In November 2000, Antigenics announced that this trial had been expanded to a phase I/II study which would now include survival as an endpoint and would enroll 5 additional patients. The US trials are being performed at Memorial Sloan-Kettering Cancer Center and the M.D. Anderson Cancer Center. The trials in Germany are being carried out at Johannes Gutenberg-University Hospital, Mainz. Oncophage is an autologous vaccine consisting of

  3. Efficacy of a Vaccine Based on Protective Antigen and Killed Spores against Experimental Inhalational Anthrax▿ ‡

    OpenAIRE

    Gauthier, Yves P.; Tournier, Jean-Nicolas; Paucod, Jean-Charles; Corre, Jean-Philippe; Mock, Michèle; Goossens, Pierre L.; Vidal, Dominique R.

    2008-01-01

    Protective antigen (PA)-based anthrax vaccines acting on toxins are less effective than live attenuated vaccines, suggesting that additional antigens may contribute to protective immunity. Several reports indicate that capsule or spore-associated antigens may enhance the protection afforded by PA. Addition of formaldehyde-inactivated spores (FIS) to PA (PA-FIS) elicits total protection against cutaneous anthrax. Nevertheless, vaccines that are effective against cutaneous anthrax may not be so...

  4. Beyond antigens and adjuvants: formulating future vaccines.

    Science.gov (United States)

    Moyer, Tyson J; Zmolek, Andrew C; Irvine, Darrell J

    2016-03-01

    The need to optimize vaccine potency while minimizing toxicity in healthy recipients has motivated studies of the formulation of vaccines to control how, when, and where antigens and adjuvants encounter immune cells and other cells/tissues following administration. An effective subunit vaccine must traffic to lymph nodes (LNs), activate both the innate and adaptive arms of the immune system, and persist for a sufficient time to promote a mature immune response. Here, we review approaches to tailor these three aspects of vaccine function through optimized formulations. Traditional vaccine adjuvants activate innate immune cells, promote cell-mediated transport of antigen to lymphoid tissues, and promote antigen retention in LNs. Recent studies using nanoparticles and other lymphatic-targeting strategies suggest that direct targeting of antigens and adjuvant compounds to LNs can also enhance vaccine potency without sacrificing safety. The use of formulations to regulate biodistribution and promote antigen and inflammatory cue co-uptake in immune cells may be important for next-generation molecular adjuvants. Finally, strategies to program vaccine kinetics through novel formulation and delivery strategies provide another means to enhance immune responses independent of the choice of adjuvant. These technologies offer the prospect of enhanced efficacy while maintaining high safety profiles necessary for successful vaccines. PMID:26928033

  5. Cysteine proteases as potential antigens in antiparasitic DNA vaccines

    DEFF Research Database (Denmark)

    Jørgensen, Louise von Gersdorff; Buchmann, Kurt

    2011-01-01

    En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner.......En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner....

  6. Designing malaria vaccines to circumvent antigen variability.

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    Ouattara, Amed; Barry, Alyssa E; Dutta, Sheetij; Remarque, Edmond J; Beeson, James G; Plowe, Christopher V

    2015-12-22

    Prospects for malaria eradication will be greatly enhanced by an effective vaccine, but parasite genetic diversity poses a major impediment to malaria vaccine efficacy. In recent pre-clinical and field trials, vaccines based on polymorphic Plasmodium falciparum antigens have shown efficacy only against homologous strains, raising the specter of allele-specific immunity such as that which plagues vaccines against influenza and HIV. The most advanced malaria vaccine, RTS,S, targets relatively conserved epitopes on the P. falciparum circumsporozoite protein. After more than 40 years of development and testing, RTS,S, has shown significant but modest efficacy against clinical malaria in phase 2 and 3 trials. Ongoing phase 2 studies of an irradiated sporozoite vaccine will ascertain whether the full protection against homologous experimental malaria challenge conferred by high doses of a whole organism vaccine can provide protection against diverse strains in the field. Here we review and evaluate approaches being taken to design broadly cross-protective malaria vaccines. PMID:26475447

  7. Potentiation of anthrax vaccines using protective antigen-expressing viral replicon vectors.

    Science.gov (United States)

    Wang, Hai-Chao; An, Huai-Jie; Yu, Yun-Zhou; Xu, Qing

    2015-02-01

    DNA vaccines require improvement for human use because they are generally weak stimulators of the immune system in humans. The efficacy of DNA vaccines can be improved using a viral replicon as vector to administer antigen of pathogen. In this study, we comprehensively evaluated the conventional non-viral DNA, viral replicon DNA or viral replicon particles (VRP) vaccines encoding different forms of anthrax protective antigen (PA) for specific immunity and protective potency against anthrax. Our current results clearly suggested that these viral replicon DNA or VRP vaccines derived from Semliki Forest virus (SFV) induced stronger PA-specific immune responses than the conventional non-viral DNA vaccines when encoding the same antigen forms, which resulted in potent protection against challenge with the Bacillus anthracis strain A16R. Additionally, the naked PA-expressing SFV replicon DNA or VRP vaccines without the need for high doses or demanding particular delivery regimens elicited robust immune responses and afforded completely protective potencies, which indicated the potential of the SFV replicon as vector of anthrax vaccines for use in clinical application. Therefore, our results suggest that these PA-expressing SFV replicon DNA or VRP vaccines may be suitable as candidate vaccines against anthrax. PMID:25102364

  8. A Review of Pneumococcal Vaccines: Current Polysaccharide Vaccine Recommendations and Future Protein Antigens

    OpenAIRE

    Daniels, Calvin C.; Rogers, P. David; Shelton, Chasity M.

    2016-01-01

    This review describes development of currently available pneumococcal vaccines, provides summary tables of current pneumococcal vaccine recommendations in children and adults, and describes new potential vaccine antigens in the pipeline. Streptococcus pneumoniae, the bacteria responsible for pneumonia, otitis media, meningitis and bacteremia, remains a cause of morbidity and mortality in both children and adults. Introductions of unconjugated and conjugated pneumococcal polysaccharide vaccine...

  9. Antigen-Specific CD4+ T Cells Recognize Epitopes of Protective Antigen following Vaccination with an Anthrax Vaccine

    OpenAIRE

    Laughlin, Elsa M.; Miller, Joseph D.; James, Eddie; Fillos, Dimitri; Ibegbu, Chris C.; Mittler, Robert S.; Akondy, Rama; Kwok, William; Ahmed, Rafi; Nepom, Gerald,

    2007-01-01

    Detection of antigen-specific CD4+ T cells is facilitated by the use of fluorescently labeled soluble peptide-major histocompatibility complex (MHC) multimers which mirror the antigen specificity of T-cell receptor recognition. We have used soluble peptide-MHC class II tetramers containing peptides from the protective antigen (PA) of Bacillus anthracis to detect circulating T cells in peripheral blood of subjects vaccinated with an anthrax vaccine. PA-specific HLA class II-restricted T lympho...

  10. Strategies for Designing and Monitoring Malaria Vaccines Targeting Diverse Antigens

    OpenAIRE

    Barry, Alyssa E; Arnott, Alicia

    2014-01-01

    After more than 50 years of intensive research and development, only one malaria vaccine candidate, “RTS,S,” has progressed to Phase 3 clinical trials. Despite only partial efficacy, this candidate is now forecast to become the first licensed malaria vaccine. Hence, more efficacious second-generation malaria vaccines that can significantly reduce transmission are urgently needed. This review will focus on a major obstacle hindering development of effective malaria vaccines: parasite antigenic...

  11. New Data on Vaccine Antigen Deficient Bordetella pertussis Isolates

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    Valérie Bouchez

    2015-09-01

    Full Text Available Evolution of Bordetella pertussis is driven by natural and vaccine pressures. Isolates circulating in regions with high vaccination coverage present multiple allelic and antigenic variations as compared to isolates collected before introduction of vaccination. Furthermore, during the last epidemics reported in regions using pertussis acellular vaccines, isolates deficient for vaccine antigens, such as pertactin (PRN, were reported to reach high proportions of circulating isolates. More sporadic filamentous hemagglutinin (FHA or pertussis toxin (PT deficient isolates were also collected. The whole genome of some recent French isolates, deficient or non-deficient in vaccine antigens, were analyzed. Transcription profiles of the expression of the main virulence factors were also compared. The invasive phenotype in an in vitro human tracheal epithelial (HTE cell model of infection was evaluated. Our genomic analysis focused on SNPs related to virulence genes known to be more likely to present allelic polymorphism. Transcriptomic data indicated that isolates circulating since the introduction of pertussis vaccines present lower transcription levels of the main virulence genes than the isolates of the pre-vaccine era. Furthermore, isolates not producing FHA present significantly higher expression levels of the entire set of genes tested. Finally, we observed that recent isolates are more invasive in HTE cells when compared to the reference strain, but no multiplication occurs within cells.

  12. Cancer-germline antigen vaccines and epigenetic enhancers

    DEFF Research Database (Denmark)

    Gjerstorff, Morten Frier; Burns, Jorge; Ditzel, Henrik Jorn

    2010-01-01

    can be achieved using epigenetic modifiers. AREAS COVERED IN THIS REVIEW: We provide an overview of the potential of CG antigens as targets for cancer immunotherapy, including advantages and disadvantages. We also discuss the current state of development of CG antigen vaccines, and the potential...... synergistic effect of combining CG antigen immunotherapeutic strategies with epigenetic modifiers. WHAT THE READER WILL GAIN: The reader will gain an overview of the past, present and future role of CG antigens in cancer immunotherapy. TAKE HOME MESSAGE: Chemoimmunotherapy using epigenetic drugs and CG...

  13. Novel vaccine strategies to T-independent antigens.

    Science.gov (United States)

    Lesinski, G B; Westerink, M A

    2001-11-01

    T cell independent antigens do not require T cell help to induce an immune response, and are characterized by a lack of immunologic memory. These antigens can be divided into two classes, TI-1 or TI-2. TI-1 antigens, such as bacterial lipopolysaccharide, are potent B-cell mitogens, capable of non-specific, polyclonal activation of B cells. In contrast, TI-2 antigens can only activate mature B cells and consist of highly repetitive structures, such as capsular polysaccharides (CPS) from bacteria. Many vaccines currently in use consist of purified capsular polysaccharides from pathogenic bacteria such as Streptococcus pneumoniae and Neisseria meningitidis. These vaccines are efficacious in immune-competent adults, however, due to their TI-2 nature, are not effective in children <2 years of age. Converting polysaccharides into T cell dependent (TD) antigens, allows children, <2, to produce an effective immune response. This review focuses on various strategies used to convert the immune response to polysaccharide antigens from TI-2 to a TD response. Conjugate vaccines, anti-idiotypic antibodies, phage display library technology and DNA vaccines are discussed. PMID:11576678

  14. Identification of two new protective pre-erythrocytic malaria vaccine antigen candidates

    Directory of Open Access Journals (Sweden)

    Patterson Noelle

    2011-03-01

    Full Text Available Abstract Background Despite years of effort, a licensed malaria vaccine is not yet available. One of the obstacles facing the development of a malaria vaccine is the extensive heterogeneity of many of the current malaria vaccine antigens. To counteract this antigenic diversity, an effective malaria vaccine may need to elicit an immune response against multiple malaria antigens, thereby limiting the negative impact of variability in any one antigen. Since most of the malaria vaccine antigens that have been evaluated in people have not elicited a protective immune response, there is a need to identify additional protective antigens. In this study, the efficacy of three pre-erythrocytic stage malaria antigens was evaluated in a Plasmodium yoelii/mouse protection model. Methods Mice were immunized with plasmid DNA and vaccinia virus vectors that expressed one, two or all three P. yoelii vaccine antigens. The immunized mice were challenged with 300 P. yoelii sporozoites and evaluated for subsequent infection. Results Vaccines that expressed any one of the three antigens did not protect a high percentage of mice against a P. yoelii challenge. However, vaccines that expressed all three antigens protected a higher percentage of mice than a vaccine that expressed PyCSP, the most efficacious malaria vaccine antigen. Dissection of the multi-antigen vaccine indicated that protection was primarily associated with two of the three P. yoelii antigens. The protection elicited by a vaccine expressing these two antigens exceeded the sum of the protection elicited by the single antigen vaccines, suggesting a potential synergistic interaction. Conclusions This work identifies two promising malaria vaccine antigen candidates and suggests that a multi-antigen vaccine may be more efficacious than a single antigen vaccine.

  15. Candidate vaccine antigens identified by antibodies from mice vaccinated with 15- or 50-kilorad-irradiated cercariae of Schistosoma mansoni.

    OpenAIRE

    Richter, D.; Harn, D A

    1993-01-01

    In murine schistosomiasis, the highest levels of resistance to cercarial challenge are obtained by vaccination with radiation-attenuated cercariae. To identify candidate vaccine antigens relevant to the vaccine model, we examined parasite antigens recognized by antibodies from mice vaccinated with irradiated cercariae of Schistosoma mansoni. To optimize recognition of a wide spectrum of antigens, several factors that influence the level of protection in this model were varied; specifically, w...

  16. Generation and Characterization of Human Monoclonal Antibodies Targeting Anthrax Protective Antigen following Vaccination with a Recombinant Protective Antigen Vaccine

    OpenAIRE

    Chi, Xiangyang; Li, Jianmin; Liu, Weicen; Wang, Xiaolin; Yin, Kexin; Liu, Ju; Zai, Xiaodong; Li, Liangliang; Song, Xiaohong; Zhang, Jun; Zhang, Xiaopeng; Yin, Ying; Fu, Ling; Xu, Junjie; Yu, Changming

    2015-01-01

    The anthrax protective antigen (PA) is the central component of the three-part anthrax toxin, and it is the primary immunogenic component in the approved AVA anthrax vaccine and the “next-generation” recombinant PA (rPA) anthrax vaccines. Animal models have indicated that PA-specific antibodies (AB) are sufficient to protect against infection with Bacillus anthracis. In this study, we investigated the PA domain specificity, affinity, mechanisms of neutralization, and synergistic effects of PA...

  17. Synthetic carbohydrate antigens for HIV vaccine design

    OpenAIRE

    Wang, Lai-Xi

    2013-01-01

    The heavy glycosylation of HIV envelope constitutes a strong defense mechanism for the virus to evade host immune response, which accounts for a major barrier for HIV vaccine development. Nevertheless, the identification of a number of glycan-dependent broadly HIV-neutralizing antibodies from HIV-infected individuals, including 2G12, PG9, PG16, PGT121-123, PGT125-128, and PGT135, strongly suggests that the defensive viral “glycan shield” can be important targets of vaccines. The novel glycan ...

  18. Chimeric Epitope Vaccine from Multistage Antigens for Lymphatic Filariasis.

    Science.gov (United States)

    Anugraha, G; Madhumathi, J; Prince, P R; Prita, P J Jeya; Khatri, V K; Amdare, N P; Reddy, M V R; Kaliraj, P

    2015-10-01

    Lymphatic filariasis, a mosquito-borne parasitic disease, affects more than 120 million people worldwide. Vaccination for filariasis by targeting different stages of the parasite will be a boon to the existing MDA efforts of WHO which required repeated administration of the drug to reduce the infection level and sustained transmission. Onset of a filaria-specific immune response achieved through antigen vaccines can act synergistically with these drugs to enhance the parasite killing. Multi-epitope vaccine approach has been proved to be successful against several parasitic diseases as it overcomes the limitations associated with the whole antigen vaccines. Earlier results from our group suggested the protective efficacy of multi-epitope vaccine comprising two immunodominant epitopes from Brugia malayi antioxidant thioredoxin (TRX), several epitopes from transglutaminase (TGA) and abundant larval transcript-2 (ALT-2). In this study, the prophylactic efficacy of the filarial epitope protein (FEP), a chimera of selective epitopes identified from our earlier study, was tested in a murine model (jird) of filariasis with L3 larvae. FEP conferred a significantly (P < 0.0001) high protection (69.5%) over the control in jirds. We also observed that the multi-epitope recombinant construct (FEP) induces multiple types of protective immune responses, thus ensuring the successful elimination of the parasite; this poses FEP as a potential vaccine candidate. PMID:26179420

  19. Enhanced protective efficacy of a chimeric form of the schistosomiasis vaccine antigen Sm-TSP-2.

    Directory of Open Access Journals (Sweden)

    Mark S Pearson

    Full Text Available The large extracellular loop of the Schistosoma mansoni tetraspanin, Sm-TSP-2, when fused to a thioredoxin partner and formulated with Freund's adjuvants, has been shown to be an efficacious vaccine against murine schistosomiasis. Moreover, Sm-TSP-2 is uniquely recognised by IgG(1 and IgG(3 from putatively resistant individuals resident in S. mansoni endemic areas in Brazil. In the present study, we expressed Sm-TSP-2 at high yield and in soluble form in E. coli without the need for a solubility enhancing fusion partner. We also expressed in E. coli a chimera called Sm-TSP-2/5B, which consisted of Sm-TSP-2 fused to the immunogenic 5B region of the hookworm aspartic protease and vaccine antigen, Na-APR-1. Sm-TSP-2 formulated with alum/CpG showed significant reductions in adult worm and liver egg burdens in two separate murine schistosomiasis challenge studies. Sm-TSP-2/5B afforded significantly greater protection than Sm-TSP-2 alone when both antigens were formulated with alum/CpG. The enhanced protection obtained with the chimeric fusion protein was associated with increased production of anti-Sm-TSP-2 antibodies and IL-4, IL-10 and IFN-γ from spleen cells of vaccinated animals. Sera from 666 individuals from Brazil who were infected with S. mansoni were screened for potentially deleterious IgE responses to Sm-TSP-2. Anti-Sm-TSP-2 IgE to this protein was not detected (also shown previously for Na-APR-1, suggesting that the chimeric antigen Sm-TSP-2/5B could be used to safely and effectively vaccinate people in areas where schistosomes and hookworms are endemic.

  20. Enhanced protective efficacy of a chimeric form of the schistosomiasis vaccine antigen Sm-TSP-2.

    Science.gov (United States)

    Pearson, Mark S; Pickering, Darren A; McSorley, Henry J; Bethony, Jeffrey M; Tribolet, Leon; Dougall, Annette M; Hotez, Peter J; Loukas, Alex

    2012-01-01

    The large extracellular loop of the Schistosoma mansoni tetraspanin, Sm-TSP-2, when fused to a thioredoxin partner and formulated with Freund's adjuvants, has been shown to be an efficacious vaccine against murine schistosomiasis. Moreover, Sm-TSP-2 is uniquely recognised by IgG(1) and IgG(3) from putatively resistant individuals resident in S. mansoni endemic areas in Brazil. In the present study, we expressed Sm-TSP-2 at high yield and in soluble form in E. coli without the need for a solubility enhancing fusion partner. We also expressed in E. coli a chimera called Sm-TSP-2/5B, which consisted of Sm-TSP-2 fused to the immunogenic 5B region of the hookworm aspartic protease and vaccine antigen, Na-APR-1. Sm-TSP-2 formulated with alum/CpG showed significant reductions in adult worm and liver egg burdens in two separate murine schistosomiasis challenge studies. Sm-TSP-2/5B afforded significantly greater protection than Sm-TSP-2 alone when both antigens were formulated with alum/CpG. The enhanced protection obtained with the chimeric fusion protein was associated with increased production of anti-Sm-TSP-2 antibodies and IL-4, IL-10 and IFN-γ from spleen cells of vaccinated animals. Sera from 666 individuals from Brazil who were infected with S. mansoni were screened for potentially deleterious IgE responses to Sm-TSP-2. Anti-Sm-TSP-2 IgE to this protein was not detected (also shown previously for Na-APR-1), suggesting that the chimeric antigen Sm-TSP-2/5B could be used to safely and effectively vaccinate people in areas where schistosomes and hookworms are endemic. PMID:22428079

  1. Immune overload: Parental attitudes toward combination and single antigen vaccines.

    Science.gov (United States)

    Hulsey, Ella; Bland, Tami

    2015-05-21

    Parental concerns have led to a recent decline in immunization coverage, resulting in outbreaks of diseases that were once under control in the US. As the CDC vaccination schedule continues to increase in complexity, the number of required injections per office visit increases as well. Some parents perceive that there is trauma associated with the administration of multiple injections, and research shows that having multiple vaccines due in a single visit is associated with delays and lower immunization rates. Combination vaccines make vaccination more efficient by incorporating the antigens of several different diseases into a single injection, but many parents worry that they may overload the child's developing immune system and leave him or her susceptible to secondary infections. This literature review synthesizes current evidence regarding the parental fear of vaccine-induced immune system overload and the fear of vaccine-associated trauma, in an attempt to understand the scope and nature of these fears. Despite the wealth of knowledge about each of these fears individually, it is still unknown which is of greater concern and how this affects parental decision-making. PMID:25891399

  2. CELLULAR VACCINES IN LISTERIOSIS: ROLE OF THE LISTERIA ANTIGEN GAPDH.

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    Ricardo eCalderon-Gonzalez

    2014-02-01

    Full Text Available The use of live Listeria-based vaccines carries serious difficulties when administrated to immunocompromised individuals. However, cellular carriers have the advantage of inducing multivalent innate immunity as well as cell-mediated immune responses, constituting novel and secure vaccine strategies in listeriosis. Here, we compare the protective efficacy of dendritic cells (DCs and macrophages and their safety. We examined the immune response of these vaccine vectors using two Listeria antigens, listeriolysin O (LLO and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH, and several epitopes such as the LLO peptides, LLO189–201 and LLO91–99 and the GAPDH peptide, GAPDH1–22. We discarded macrophages as safe vaccine vectors because they show anti-Listeria protection but also high cytotoxicity. DCs loaded with GAPDH1–22 peptide conferred higher protection and security against listeriosis than the widely explored LLO91–99 peptide. Anti-Listeria protection was related to the changes in DC maturation caused by these epitopes, with high production of interleukin-12 as well as significant levels of other Th1 cytokines such as monocyte chemotactic protein-1, tumor necrosis factor-α, and interferon-γ, and with the induction of GAPDH1–22-specific CD4+ and CD8+ immune responses. This is believed to be the first study to explore the use of a novel GAPDH antigen as a potential DC-based vaccine candidate for listeriosis, whose efficiency appears to highlight the relevance of vaccine designs containing multiple CD4+ and CD8+ epitopes.

  3. Comparison of melanoma antigens in whole tumor vaccine to those from IIB-MEL-J cells.

    Science.gov (United States)

    McGee, J M; Patten, M R; Malnar, K F; Price, J A; Mayes, J S; Watson, G H

    1999-06-01

    Immunotherapy for melanoma shows promise. Our previous whole tumor (WT) vaccine was noted to have positive clinical effects. We have now developed a new, safer melanoma vaccine that is derived from IIB-MEL-J tissue culture (TC) cells. In this study, we compare by Western blot analyses the antigens in the WT vaccine to antigens in the TC vaccine. Sera from 12 WT vaccine recipients, 8 melanoma patients who received no immunotherapy, and 8 controls served as a source of antibodies to investigate potential antigens in the vaccines. Three major antigenic peptides with approximate molecular weighs of 46, 40, and 36 kDA were present in both vaccines, while two other antigenic peptides with approximate molecular weighs of 68 and 48 kDA were present only in the TC vaccine. The reaction was similar between the patients who received the WT vaccine and those who did not receive the vaccine. Some of the individuals who did not have melanoma showed some reaction, but not to the extent of the melanoma patients. The intensity of immunostaining was greater for the TC vaccine when compared to the WT vaccine, indicating that these proteins are in a higher concentration in the TC vaccine. This new vaccine from IIB-MEL-J tissue culture cells provides a higher yield and a much more consistent source of potentially clinically relevant antigens without risk of infection or contamination by other irrelevant materials. PMID:10850304

  4. A New Vaccine against Tuberculosis Affords Greater Survival after Challenge than the Current Vaccine in the Guinea Pig Model of Pulmonary Tuberculosis

    OpenAIRE

    Horwitz, Marcus A.; Harth, Guenter

    2003-01-01

    Tuberculosis (TB) remains an enormous global health problem, and a new vaccine against TB more potent than the current inadequate vaccine, Mycobacterium bovis BCG, is urgently needed. We describe a recombinant BCG vaccine (rBCG30) expressing and secreting the 30-kDa major secretory protein of Mycobacterium tuberculosis, the primary causative agent of TB, that affords greater survival after challenge than parental BCG in the highly demanding guinea pig model of pulmonary TB. Animals immunized ...

  5. Antigen-Specific Antibody Glycosylation Is Regulated via Vaccination.

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    Alison E Mahan

    2016-03-01

    Full Text Available Antibody effector functions, such as antibody-dependent cellular cytotoxicity, complement deposition, and antibody-dependent phagocytosis, play a critical role in immunity against multiple pathogens, particularly in the absence of neutralizing activity. Two modifications to the IgG constant domain (Fc domain regulate antibody functionality: changes in antibody subclass and changes in a single N-linked glycan located in the CH2 domain of the IgG Fc. Together, these modifications provide a specific set of instructions to the innate immune system to direct the elimination of antibody-bound antigens. While it is clear that subclass selection is actively regulated during the course of natural infection, it is unclear whether antibody glycosylation can be tuned, in a signal-specific or pathogen-specific manner. Here, we show that antibody glycosylation is determined in an antigen- and pathogen-specific manner during HIV infection. Moreover, while dramatic differences exist in bulk IgG glycosylation among individuals in distinct geographical locations, immunization is able to overcome these differences and elicit antigen-specific antibodies with similar antibody glycosylation patterns. Additionally, distinct vaccine regimens induced different antigen-specific IgG glycosylation profiles, suggesting that antibody glycosylation is not only programmable but can be manipulated via the delivery of distinct inflammatory signals during B cell priming. These data strongly suggest that the immune system naturally drives antibody glycosylation in an antigen-specific manner and highlights a promising means by which next-generation therapeutics and vaccines can harness the antiviral activity of the innate immune system via directed alterations in antibody glycosylation in vivo.  .

  6. Antigen-Specific Antibody Glycosylation Is Regulated via Vaccination.

    Science.gov (United States)

    Mahan, Alison E; Jennewein, Madeleine F; Suscovich, Todd; Dionne, Kendall; Tedesco, Jacquelynne; Chung, Amy W; Streeck, Hendrik; Pau, Maria; Schuitemaker, Hanneke; Francis, Don; Fast, Patricia; Laufer, Dagna; Walker, Bruce D; Baden, Lindsey; Barouch, Dan H; Alter, Galit

    2016-03-01

    Antibody effector functions, such as antibody-dependent cellular cytotoxicity, complement deposition, and antibody-dependent phagocytosis, play a critical role in immunity against multiple pathogens, particularly in the absence of neutralizing activity. Two modifications to the IgG constant domain (Fc domain) regulate antibody functionality: changes in antibody subclass and changes in a single N-linked glycan located in the CH2 domain of the IgG Fc. Together, these modifications provide a specific set of instructions to the innate immune system to direct the elimination of antibody-bound antigens. While it is clear that subclass selection is actively regulated during the course of natural infection, it is unclear whether antibody glycosylation can be tuned, in a signal-specific or pathogen-specific manner. Here, we show that antibody glycosylation is determined in an antigen- and pathogen-specific manner during HIV infection. Moreover, while dramatic differences exist in bulk IgG glycosylation among individuals in distinct geographical locations, immunization is able to overcome these differences and elicit antigen-specific antibodies with similar antibody glycosylation patterns. Additionally, distinct vaccine regimens induced different antigen-specific IgG glycosylation profiles, suggesting that antibody glycosylation is not only programmable but can be manipulated via the delivery of distinct inflammatory signals during B cell priming. These data strongly suggest that the immune system naturally drives antibody glycosylation in an antigen-specific manner and highlights a promising means by which next-generation therapeutics and vaccines can harness the antiviral activity of the innate immune system via directed alterations in antibody glycosylation in vivo.  . PMID:26982805

  7. Comparative efficacy of Bacillus anthracis live spore vaccine and protective antigen vaccine against anthrax in the guinea pig.

    OpenAIRE

    Little, S F; Knudson, G B

    1986-01-01

    Several strains of Bacillus anthracis have been reported previously to cause fatal infection in immunized guinea pigs. In this study, guinea pigs were immunized with either a protective antigen vaccine or a live Sterne strain spore vaccine, then challenged with virulent B. anthracis strains isolated from various host species from the United States and foreign sources. Confirmation of previously reported studies (which used only protective antigen vaccines) was made with the identification of ...

  8. Probing vaccine antigens against bovine mastitis caused by Streptococcus uberis.

    Science.gov (United States)

    Collado, Rosa; Prenafeta, Antoni; González-González, Luis; Pérez-Pons, Josep Antoni; Sitjà, Marta

    2016-07-19

    Streptococcus uberis is a worldwide pathogen that causes intramammary infections in dairy cattle. Because virulence factors determining the pathogenicity of S. uberis have not been clearly identified so far, a commercial vaccine is not yet available. Different S. uberis strains have the ability to form biofilm in vitro, although the association of this kind of growth with the development of mastitis is unknown. The objective of this study was to evaluate the potential use as vaccine antigens of proteins from S. uberis biofilms, previously identified by proteomic and immunological analyses. The capability of eliciting a protective immune response by targeted candidates was assayed on a murine model. Sera from rabbits immunized with S. uberis biofilm preparations and a convalescent cow intra-mammary infected with S. uberis were probed against cell wall proteins from biofilm and planktonic cells previously separated by two-dimensional gel electrophoresis. Using rabbit immunized serum, two proteins were found to be up-regulated in biofilm cells as compared to planktonic cells; when serum from the convalescent cow was used, up to sixteen biofilm proteins were detected. From these proteins, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), fructose-biphosphate aldolase (FBA), and elongation factor Ts (EFTs) were chosen to be tested as vaccine antigen candidates. For this purpose, different groups of mice were immunized with the three recombinant-expressed proteins (each one formulated separately in a vaccine), and thereafter intraperitoneally challenged with S. uberis. The three proteins induced specific IgG antibodies, but a significant reduction of mortality was only observed in the groups of mice vaccinated with FBA or EFTs. These results suggest that FBA and EFTs might be considered as strong antigenic candidates for a vaccine against S. uberis bovine mastitis. Moreover, this is the first study to indicate that also in S. uberis, GAPDH, FBA and EFTs, as proteins

  9. Generation and Characterization of Human Monoclonal Antibodies Targeting Anthrax Protective Antigen following Vaccination with a Recombinant Protective Antigen Vaccine.

    Science.gov (United States)

    Chi, Xiangyang; Li, Jianmin; Liu, Weicen; Wang, Xiaolin; Yin, Kexin; Liu, Ju; Zai, Xiaodong; Li, Liangliang; Song, Xiaohong; Zhang, Jun; Zhang, Xiaopeng; Yin, Ying; Fu, Ling; Xu, Junjie; Yu, Changming; Chen, Wei

    2015-05-01

    The anthrax protective antigen (PA) is the central component of the three-part anthrax toxin, and it is the primary immunogenic component in the approved AVA anthrax vaccine and the "next-generation" recombinant PA (rPA) anthrax vaccines. Animal models have indicated that PA-specific antibodies (AB) are sufficient to protect against infection with Bacillus anthracis. In this study, we investigated the PA domain specificity, affinity, mechanisms of neutralization, and synergistic effects of PA-specific antibodies from a single donor following vaccination with the rPA vaccine. Antibody-secreting cells were isolated 7 days after the donor received a boost vaccination, and 34 fully human monoclonal antibodies (hMAb) were identified. Clones 8H6, 4A3, and 22F1 were able to neutralize lethal toxin (LeTx) both in vitro and in vivo. Clone 8H6 neutralized LeTx by preventing furin cleavage of PA in a dose-dependent manner. Clone 4A3 enhanced degradation of nicked PA, thereby interfering with PA oligomerization. The mechanism of 22F1 is still unclear. A fourth clone, 2A6, that was protective only in vitro was found to be neutralizing in vivo in combination with a toxin-enhancing antibody, 8A7, which binds to domain 3 of PA and PA oligomers. These results provide novel insights into the antibody response elicited by the rPA vaccine and may be useful for PA-based vaccine and immunotherapeutic cocktail design. PMID:25787135

  10. TH1 and TH2 responses are influenced by HLA antigens in healthy neonates vaccinated with recombinant hepatitis B vaccine.

    OpenAIRE

    Abdollah Jafarzadeh; Fazel Shokri

    2012-01-01

    The immune response to hepatitis B surface antigen (HBsAg) is influenced by several factors, of which HLA antigens and balanced secretion of Th1/Th2 cytokines play important roles. The aim of this study was to evaluate the influence of HLA antigens on cytokine secretion by HBsAg-stimulated peripheral blood mononuclear cells (PBMC) from healthy neonates vaccinated with recombinant HBsAg. PBMCs were isolated from 48 Iranian neonates vaccinated with a recombinant HBV vaccine. The cells were stim...

  11. INFLUENCE OF IMMUNOMODULATION ON THE FIRST STAGE OF ANTIGEN SPECIFIC RESPONSE TO HERPES VACCINE IN EXPERIMENT

    Directory of Open Access Journals (Sweden)

    MARIA OMAROVA

    2011-08-01

    Full Text Available The influence of immunomodulation on dynamics of early antigen specific response (antigen binding lymphocytes - ABL was studied in the experiment with rabbits immunization by herpes vaccine. Acceleration of appearance and disappearance of ABL after one-time immunization with herpes vaccine by introduction of licensed preparations of interleukin-1, interleukin-2, polyoxidonium and interferon inductor bacterial was revealed.

  12. Proteome-wide antigen discovery of novel protective vaccine candidates against Staphylococcus aureus infection

    DEFF Research Database (Denmark)

    Rasmussen, Karina Juhl; Mattsson, Andreas Holm; Pilely, Katrine;

    2016-01-01

    is an urgent need to institute non-antimicrobial measures, such as vaccination, against the spread of MRSA. With the aim of finding new protective antigens for vaccine development, this study used a proteome-wide in silico antigen prediction platform to screen the proteome of S. aureus strain MRSA252...

  13. Effect of particulate adjuvant on the anthrax protective antigen dose required for effective nasal vaccination.

    Science.gov (United States)

    Bento, Dulce; Staats, Herman F; Borges, Olga

    2015-07-17

    Successful vaccine development is dependent on the development of effective adjuvants since the poor immunogenicity of modern subunit vaccines typically requires the use of potent adjuvants and high antigen doses. In recent years, adjuvant formulations combining both immunopotentiators and delivery systems have emerged as a promising strategy to develop effective and improved vaccines. In this study we investigate if the association of the mast cell activating adjuvant compound 48/80 (C48/80) with chitosan nanoparticles would promote an antigen dose sparing effect when administered intranasally. Even though the induction of strong mucosal immunity required higher antigen doses, incorporation of C48/80 into nanoparticles provided significant dose sparing when compared to antigen and C48/80 in solution with no significant effect on serum neutralizing antibodies titers. These results suggest the potential of this novel adjuvant combination to improve the immunogenicity of a vaccine and decrease the antigen dose required for vaccination. PMID:26087299

  14. Primary vaccination of adults with reduced antigen-content diphtheria-tetanus-acellular pertussis or dTpa-inactivated poliovirus vaccines compared to diphtheria-tetanus-toxoid vaccines.

    NARCIS (Netherlands)

    Theeten, H.; Rumke, H.C.; Hoppener, F.J.; Vilatimo, R.; Narejos, S.; Damme, P. van; Hoet, B.

    2007-01-01

    OBJECTIVE: To evaluate immunogenicity and reactogenicity of primary vaccination with reduced-antigen-content diphtheria-tetanus-acellular pertussis (dTpa) or dTpa-inactivated poliovirus (dTpa-IPV) vaccine compared to diphtheria-tetanus-toxoid vaccines (Td) in adults > or = 40 years of age without

  15. Influenza virosomes supplemented with GPI-0100 adjuvant: a potent vaccine formulation for antigen dose sparing

    OpenAIRE

    Liu, Heng; de Vries-Idema, Jacqueline; ter Veer, Wouter; Wilschut, Jan; Huckriede, Anke

    2014-01-01

    Adjuvants can stimulate vaccine-induced immune responses and can contribute decisively to antigen dose sparing when vaccine antigen production is limited, as for example during a pandemic influenza outbreak. We earlier showed that GPI-0100, a semi-synthetic saponin derivative with amphiphilic structure, significantly stimulates the immunogenicity and protective efficacy of influenza subunit vaccine administered via a systemic route. Here, we evaluated the adjuvant effect of GPI-0100 on a viro...

  16. Comparison of IFN-gamma responses to mycobacterial antigens as markers of response to BCG vaccination.

    Science.gov (United States)

    Weir, Rosemary E; Fine, Paul E M; Floyd, Sian; Stenson, Sally; Stanley, Carolynne; Branson, Keith; Britton, Warwick J; Huygen, Kris; Singh, Mahavir; Black, Gillian; Dockrell, Hazel M

    2008-01-01

    An increase in interferon-gamma (IFN-gamma) production to Mycobacterium tuberculosis purified protein derivative (Mtb PPD), as measured in the cultured diluted whole blood assay, is one indicator of a protective immune response to BCG vaccine. We have explored the potential for this assay to be improved by measuring IFN-gamma responses to more defined antigens of M. tuberculosis (short-term and mid-term culture filtrates, ESAT-6, 38 kDa), Mycobacterium bovis (MPB70), M. bovis BCG (Antigen 85) and Mycobacterium leprae (35 kDa), in UK teenagers before and 1 year after BCG vaccination (or no vaccination as controls). There was a significant increase in response to the culture filtrates post-vaccination, but this was no greater than that to Mtb PPD. Many teenagers responded to the purified antigens, in particular to Antigen 85, prior to vaccination, and BCG vaccination could only augment this pre-existing response to a limited extent; prior exposure to environmental mycobacteria can thus induce cross-reactive responses to antigens which complicate interpretation of in vitro assays of vaccine response. In contrast, ESAT-6 was recognised by only one teenager prior to vaccination, and, as expected, responses were not boosted by BCG. We therefore conclude that Mtb PPD is the antigen preparation of choice for assessing the immunogenicity of BCG vaccination. PMID:18277396

  17. Exposed and concealed antigens as vaccine targets for controlling ticks and tick-borne diseases.

    Science.gov (United States)

    Nuttall, P A; Trimnell, A R; Kazimirova, M; Labuda, M

    2006-04-01

    Tick vaccines derived from Bm86, a midgut membrane-bound protein of the cattle tick, Boophilus microplus, are currently the only commercially available ectoparasite vaccines. Despite its introduction to the market in 1994, and the recognized need for alternatives to chemical pesticides, progress in developing effective antitick vaccines (and ectoparasite vaccines in general) is slow. The primary rate-limiting step is the identification of suitable antigenic targets for vaccine development. Two sources of candidate vaccine antigens have been identified: 'exposed' antigens that are secreted in tick saliva during attachment and feeding on a host and 'concealed' antigens that are normally hidden from the host. Recently, a third group of antigens has been distinguished that combines the properties of both exposed and concealed antigens. This latter group offers the prospect of a broad-spectrum vaccine effective against both adults and immature stages of a wide variety of tick species. It also shows transmission-blocking and protective activity against a tick-borne pathogen. With the proliferation of molecular techniques and their application to vaccine development, there are high hopes for new and effective antitick vaccines that also control tick-borne diseases. PMID:16542317

  18. Intellectual property rights and challenges for development of affordable human papillomavirus, rotavirus and pneumococcal vaccines: Patent landscaping and perspectives of developing country vaccine manufacturers.

    Science.gov (United States)

    Chandrasekharan, Subhashini; Amin, Tahir; Kim, Joyce; Furrer, Eliane; Matterson, Anna-Carin; Schwalbe, Nina; Nguyen, Aurélia

    2015-11-17

    The success of Gavi, the Vaccine Alliance depends on the vaccine markets providing appropriate, affordable vaccines at sufficient and reliable quantities. Gavi's current supplier base for new and underutilized vaccines, such as the human papillomavirus (HPV), rotavirus, and the pneumococcal conjugate vaccine is very small. There is growing concern that following globalization of laws on intellectual property rights (IPRs) through trade agreements, IPRs are impeding new manufacturers from entering the market with competing vaccines. This article examines the extent to which IPRs, specifically patents, can create such obstacles, in particular for developing country vaccine manufacturers (DCVMs). Through building patent landscapes in Brazil, China, and India and interviews with manufacturers and experts in the field, we found intense patenting activity for the HPV and pneumococcal vaccines that could potentially delay the entry of new manufacturers. Increased transparency around patenting of vaccine technologies, stricter patentability criteria suited for local development needs and strengthening of IPRs management capabilities where relevant, may help reduce impediments to market entry for new manufacturers and ensure a competitive supplier base for quality vaccines at sustainably low prices. PMID:26368398

  19. Dynamics of polymorphism in a malaria vaccine antigen at a vaccine-testing site in Mali.

    Directory of Open Access Journals (Sweden)

    Shannon L Takala

    2007-03-01

    Full Text Available BACKGROUND: Malaria vaccines based on the 19-kDa region of merozoite surface protein 1 (MSP-1(19 derived from the 3D7 strain of Plasmodium falciparum are being tested in clinical trials in Africa. Knowledge of the distribution and natural dynamics of vaccine antigen polymorphisms in populations in which malaria vaccines will be tested will guide vaccine design and permit distinction between natural fluctuations in genetic diversity and vaccine-induced selection. METHODS AND FINDINGS: Using pyrosequencing, six single-nucleotide polymorphisms in the nucleotide sequence encoding MSP-1(19 were genotyped from 1,363 malaria infections experienced by 100 children who participated in a prospective cohort study in Mali from 1999 to 2001. The frequencies of 14 MSP-1(19 haplotypes were compared over the course of the malaria transmission season for all three years, in three age groups, and in consecutive infections within individuals. While the frequency of individual MSP-1(19 haplotypes fluctuated, haplotypes corresponding to FVO and FUP strains of P. falciparum (MSP-1(19 haplotypes QKSNGL and EKSNGL, respectively were most prevalent during three consecutive years and in all age groups with overall prevalences of 46% (95% confidence interval [CI] 44%-49% and 36% (95% CI 34%-39%, respectively. The 3D7 haplotype had a lower overall prevalence of 16% (95% CI 14%-18%. Multiplicity of infection based on MSP-1(19 was higher at the beginning of the transmission season and in the oldest individuals (aged > or =11 y. Three MSP-1(19 haplotypes had a reduced frequency in symptomatic infections compared to asymptomatic infections. Analyses of the dynamics of MSP-1(19 polymorphisms in consecutive infections implicate three polymorphisms (at positions 1691, 1700, and 1701 as being particularly important in determining allele specificity of anti-MSP-1(19 immunity. CONCLUSIONS: Parasites with MSP-1(19 haplotypes different from that of the leading vaccine strain were

  20. Current status of multiple antigen-presenting peptide vaccine systems: Application of organic and inorganic nanoparticles

    Directory of Open Access Journals (Sweden)

    Taguchi Hiroaki

    2011-08-01

    Full Text Available Abstract Many studies are currently investigating the development of safe and effective vaccines to prevent various infectious diseases. Multiple antigen-presenting peptide vaccine systems have been developed to avoid the adverse effects associated with conventional vaccines (i.e., live-attenuated, killed or inactivated pathogens, carrier proteins and cytotoxic adjuvants. Recently, two main approaches have been used to develop multiple antigen-presenting peptide vaccine systems: (1 the addition of functional components, e.g., T-cell epitopes, cell-penetrating peptides, and lipophilic moieties; and (2 synthetic approaches using size-defined nanomaterials, e.g., self-assembling peptides, non-peptidic dendrimers, and gold nanoparticles, as antigen-displaying platforms. This review summarizes the recent experimental studies directed to the development of multiple antigen-presenting peptide vaccine systems.

  1. Analysis of Antibody Responses to Protective Antigen-Based Anthrax Vaccines through Use of Competitive Assays▿

    OpenAIRE

    Rebecca A Brady; Verma, Anita; Meade, Bruce D.; Burns, Drusilla L.

    2010-01-01

    The licensed anthrax vaccine and many of the new anthrax vaccines being developed are based on protective antigen (PA), a nontoxic component of anthrax toxin. For this reason, an understanding of the immune response to PA vaccination is important. In this study, we examined the antibody response elicited by PA-based vaccines and identified the domains of PA that contribute to that response in humans as well as nonhuman primates (NHPs) and rabbits, animal species that will be used to generate ...

  2. Elucidating the mechanisms of protein antigen adsorption to the CAF/NAF liposomal vaccine adjuvant systems

    DEFF Research Database (Denmark)

    Hamborg, Mette; Rose, Fabrice; Jorgensen, Lene;

    2014-01-01

    The reverse vaccinology approach has recently resulted in the identification of promising protein antigens, which in combination with appropriate adjuvants can stimulate customized, protective immune responses. Although antigen adsorption to adjuvants influences vaccine efficacy and safety, little...... attractive interaction with the zwitterionic liposomes. In contrast, the net cationic lysozyme showed very little interaction with either types of liposome. Adsorption of α-lactalbumin altered its tertiary structure, affected lipid membrane packing below and above the phase transition temperature, and...... way vaccine antigens are presented to antigen-presenting cells, and may play an important role for the efficacy of the vaccine-induced immune response. These studies thus exemplify the importance of characterizing the molecular interactions between the vaccine antigen and adjuvant along with...

  3. Clearance of depot vaccine SPIO-labeled antigen and substrate visualized using MRI.

    Science.gov (United States)

    Brewer, Kimberly D; Lake, Kerry; Pelot, Nicole; Stanford, Marianne M; DeBay, Drew R; Penwell, Andrea; Weir, Genevieve M; Karkada, Mohan; Mansour, Marc; Bowen, Chris V

    2014-12-01

    Immunotherapies, including peptide-based vaccines, are a growing area of cancer research, and understanding their mechanism of action is crucial for their continued development and clinical application. Exploring the biodistribution of vaccine components may be key to understanding this action. This work used magnetic resonance imaging (MRI) to characterize the in vivo biodistribution of the antigen and oil substrate of the vaccine delivery system known as DepoVax(TM). DepoVax uses a novel adjuvanted lipid-in-oil based formulation to solubilise antigens and promote a depot effect. In this study, antigen or oil were tagged with superparamagnetic iron oxide (SPIO), making them visible on MR images. This enables tracking of individual vaccine components to determine changes in biodistribution. Mice were injected with SPIO-labeled antigen or SPIO-labeled oil, and imaged to examine clearance of labeled components from the vaccine site. The SPIO-antigen was steadily cleared, with nearly half cleared within two months post-vaccination. In contrast, the SPIO-oil remained relatively unchanged. The biodistribution of the SPIO-antigen component within the vaccine site was heterogeneous, indicating the presence of active clearance mechanisms, rather than passive diffusion or drainage. Mice injected with SPIO-antigen also showed MRI contrast for several weeks post-vaccination in the draining inguinal lymph node. These results indicate that MRI can visualize the in vivo longitudinal biodistribution of vaccine components. The sustained clearance is consistent with antigen up-take and trafficking by immune cells, leading to accumulation in the draining lymph node, which corresponds to the sustained immune responses and reduced tumor burden observed in vaccinated mice. PMID:25444822

  4. Complex Minigene Library Vaccination for Discovery of Pre-Erythrocytic Plasmodium T Cell Antigens

    Science.gov (United States)

    Stone, Brad C.; Kas, Arnold; Billman, Zachary P.; Fuller, Deborah H.; Fuller, James T.; Shendure, Jay; Murphy, Sean C.

    2016-01-01

    Development of a subunit vaccine targeting liver-stage Plasmodium parasites requires the identification of antigens capable of inducing protective T cell responses. However, traditional methods of antigen identification are incapable of evaluating T cell responses against large numbers of proteins expressed by these parasites. This bottleneck has limited development of subunit vaccines against Plasmodium and other complex intracellular pathogens. To address this bottleneck, we are developing a synthetic minigene technology for multi-antigen DNA vaccines. In an initial test of this approach, pools of long (150 bp) antigen-encoding oligonucleotides were synthesized and recombined into vectors by ligation-independent cloning to produce two DNA minigene library vaccines. Each vaccine encoded peptides derived from 36 (vaccine 1) and 53 (vaccine 2) secreted or transmembrane pre-erythrocytic P. yoelii proteins. BALB/cj mice were vaccinated three times with a single vaccine by biolistic particle delivery (gene gun) and screened for interferon-γ-producing T cell responses by ELISPOT. Library vaccination induced responses against four novel antigens. Naïve mice exposed to radiation-attenuated sporozoites mounted a response against only one of the four novel targets (PyMDH, malate dehydrogenase). The response to PyMDH could not be recalled by additional homologous sporozoite immunizations but could be partially recalled by heterologous cross-species sporozoite exposure. Vaccination against the dominant PyMDH epitope by DNA priming and recombinant Listeria boosting did not protect against sporozoite challenge. Improvements in library design and delivery, combined with methods promoting an increase in screening sensitivity, may enable complex minigene screening to serve as a high-throughput system for discovery of novel T cell antigens. PMID:27070430

  5. Challenges to the development of antigen-specific breast cancer vaccines

    International Nuclear Information System (INIS)

    Continued progress in the development of antigen-specific breast cancer vaccines depends on the identification of appropriate target antigens, the establishment of effective immunization strategies, and the ability to circumvent immune escape mechanisms. Methods such as T cell epitope cloning and serological expression cloning (SEREX) have led to the identification of a number target antigens expressed in breast cancer. Improved immunization strategies, such as using dendritic cells to present tumor-associated antigens to T lymphocytes, have been shown to induce antigen-specific T cell responses in vivo and, in some cases, objective clinical responses. An outcome of successful tumor immunity is the evolution of antigen-loss tumor variants. The development of a polyvalent breast cancer vaccine, directed against a panel of tumor-associated antigens, may counteract this form of immune escape

  6. Production of schistosome antigens for immunodiagnosis and vaccines: the role of recombinant DNA technology

    International Nuclear Information System (INIS)

    A major problem to confront biochemists studying the immunology of parasitic infection is a paucity of the organisms themselves. Conventional biochemical techniques for the isolation and purification of individual antigens are inappropriate. This problem has been alleviated by the application of recombinant DNA technology. It is now possible to produce large quantities of individual antigens by cloning the corresponding genes into plasmids (or other vectors) and subsequent expression in bacteria. Antigens produced in this way may provide the basis of a specific diagnostic test and vaccines. This paper describes the identification of cDNA clones of Schistosoma mansoni which encode a major egg antigen and schistosomula surface antigens. These antigens are thought to be species specific and may form the basis of a diagnostic test. The schistosomula antigens are also possible candidates for inclusion in an experimental vaccine against infection with S. mansoni. (author)

  7. Scaffolded Antigens in Yeast Cell Particle Vaccines Provide Protection against Systemic Polyoma Virus Infection

    OpenAIRE

    Tipper, Donald J.; Szomolanyi-Tsuda, Eva

    2016-01-01

    Background. U65, a self-aggregating peptide scaffold, traps fused protein antigens in yeast cells. Conversion to Yeast Cell Particle (YCP) vaccines by partial removal of surface mannoproteins exposes β-glucan, mediating efficient uptake by antigen-presenting cells (APCs). YCP vaccines are inexpensive, capable of rapid large-scale production and have potential for both parenteral and oral use. Results. YCP processing by alkaline hydrolysis exposes up to 20% of the glucan but converts scaffolde...

  8. Liposome-Based Adjuvants for Subunit Vaccines: Formulation Strategies for Subunit Antigens and Immunostimulators

    Directory of Open Access Journals (Sweden)

    Signe Tandrup Schmidt

    2016-03-01

    Full Text Available The development of subunit vaccines has become very attractive in recent years due to their superior safety profiles as compared to traditional vaccines based on live attenuated or whole inactivated pathogens, and there is an unmet medical need for improved vaccines and vaccines against pathogens for which no effective vaccines exist. The subunit vaccine technology exploits pathogen subunits as antigens, e.g., recombinant proteins or synthetic peptides, allowing for highly specific immune responses against the pathogens. However, such antigens are usually not sufficiently immunogenic to induce protective immunity, and they are often combined with adjuvants to ensure robust immune responses. Adjuvants are capable of enhancing and/or modulating immune responses by exposing antigens to antigen-presenting cells (APCs concomitantly with conferring immune activation signals. Few adjuvant systems have been licensed for use in human vaccines, and they mainly stimulate humoral immunity. Thus, there is an unmet demand for the development of safe and efficient adjuvant systems that can also stimulate cell-mediated immunity (CMI. Adjuvants constitute a heterogeneous group of compounds, which can broadly be classified into delivery systems or immunostimulators. Liposomes are versatile delivery systems for antigens, and they can carefully be customized towards desired immune profiles by combining them with immunostimulators and optimizing their composition, physicochemical properties and antigen-loading mode. Immunostimulators represent highly diverse classes of molecules, e.g., lipids, nucleic acids, proteins and peptides, and they are ligands for pattern-recognition receptors (PRRs, which are differentially expressed on APC subsets. Different formulation strategies might thus be required for incorporation of immunostimulators and antigens, respectively, into liposomes, and the choice of immunostimulator should ideally be based on knowledge regarding the

  9. Non-cytolytic antigen clearance in DNA-vaccinated mice with electropotation

    Institute of Scientific and Technical Information of China (English)

    Jin-liang PENG; Yong-gang ZHAO; Jun-hua MAI; Wen-ka PANG; Wei GUO; Guang-ming CHEN; Guo-yu MO; Gui-rong RAO; Yu-hong XU

    2007-01-01

    Aim: To explore the potential of electroporation (EP)-mediated hepatitis B virus (HBV) DNA vaccination for the treatment of chronic HBV infection. Methods: BALB/c mice were vaccinated with HBV DNA vaccine encoding for the HBV preS2-S antigen, combined with or without EP. HBV surface antigen expression plasmid was administered into mice liver via a hydrodynamic injection to mimic HBV infection. The clearance of antigen in the serum and liver was detected by ELISA assay and immunohistochemical staining. The histopathology of the liver tissues was examined by HE staining and serum alanine aminotransferase assay.Results: The immunogenicity ofHBV DNA vaccine encoding for the HBV preS2-S antigen can be improved by EP-mediated vaccine delivery. The elicited immune responses can indeed reduce the expression of HBV surface antigen (HBsAg) in hepatocytes of the mouse model that was transfected to express HBsAg using the hydrodynamic injection method. The antigen clearance process did not cause significant toxicity to liver tissue, suggesting a non-cytolytic mechanism. Conclusion: The EP-aided DNA vaccination may have potential in mediating viral clearance in chronic hepatitis B patients.

  10. A Novel Laser Vaccine Adjuvant Increases the Motility of Antigen Presenting Cells

    OpenAIRE

    Farinelli, Bill; Doukas, Apostolos; Gelfand, Jeffrey Alan; Anderson, Richard Rox; Mei X. Wu; Chen, Xinyuan; Kim, Pilhan; Yun, Seok-Hyun

    2010-01-01

    Background Development of a potent vaccine adjuvant without introduction of any side effects remains an unmet challenge in the field of the vaccine research. Methodology/Principal Findings We found that laser at a specific setting increased the motility of antigen presenting cells (APCs) and immune responses, with few local or systemic side effects. This laser vaccine adjuvant (LVA) effect was induced by brief illumination of a small area of the skin or muscle with a nondestructive...

  11. Limitations of plasmid vaccines to complex viruses: selected myxoma virus antigens as DNA vaccines were not protective.

    Science.gov (United States)

    Adams, Mathew M; van Leeuwen, Barbara H; Kerr, Peter J

    2004-11-25

    Myxoma virus, a poxvirus of the genus Leporipoxvirus, is the causative agent of the disease myxomatosis which is highly lethal in European rabbits (Oryctolagus cuniculus). Current vaccines to protect against myxomatosis are either attenuated live strains of the virus or the antigenically related rabbit fibroma virus. We examined the immune response of outbred domestic rabbits to the individual myxoma virus antigens M055R, M073R, M115L and M121R, delivered as DNA vaccines co-expressing rabbit interleukin-2 or interleukin-4. M115L and M121R were also delivered simultaneously. None of the vaccine constructs were able to protect the rabbits from disease or reduce mortality after challenge with virulent myxoma virus, despite induction of antigen-specific cell-mediated and humoral immune responses. PMID:15531037

  12. Influenza A vaccines using linear expression cassettes delivered via electroporation afford full protection against challenge in a mouse model.

    Science.gov (United States)

    Shen, Xuefei; Söderholm, Jonas; Lin, Feng; Kobinger, Gary; Bello, Alexander; Gregg, Derek A; Broderick, Kate E; Sardesai, Niranjan Y

    2012-11-01

    Alternative DNA vaccine constructs such as fully synthetic linear expressing cassettes (LECs) offer the advantage of accelerated manufacturing techniques as well as the lack of both antibiotic resistance genes and bacterial contaminants. The speed of manufacture makes LEC technology a possible future vaccination strategy for pandemic influenza outbreaks. Previously, we reported on a novel concept of DNA delivery to dermal tissue by a minimally invasive electroporation (EP) surface device powered using low voltage parameters. This device allows electroporation without penetration of electrodes into the skin. In addition to enhancing the delivery of traditional plasmid DNA vaccines, this device may also offer a safe, tolerable and efficient method to administer LECs. To assess immunogenicity and efficacy of EP-enhanced LEC delivery in mice, we designed and tested two influenza antigens in the form of LEC constructs delivered using the newly developed surface dermal EP device. Strong CTL and antibody responses were induced by the LEC versions of the DNA vaccine. When challenged with A/Canada/AB/RV1532/2009 viruses, mice immunized with LEC encoding the M2 and NP antigens recovered faster than naïve or mice immunized ID without EP. Mice immunized with equal-molar doses of LEC encoding the M2 and NP antigens demonstrated 100% survival following a lethal (100× LD50) challenge of the heterologuos and highly pathogenic H5N1 influenza virus (A/Vietnam/1203/04). These results suggest that influenza DNA vaccines based on LEC technology combined with the surface delivery platform are capable of fully protecting mice in a lethal challenge and the LEC based DNA constructs may serve as viable vaccine candidates. PMID:22406460

  13. Protective efficacy of vaccination with Neospora caninum multiple recombinant antigens against experimental Neospora caninum infection

    OpenAIRE

    Cho, Jung-Hwa; Chung, Woo-Suk; Song, Kyoung-Ju; Na, Byoung-kuk; Kang, Seung-Won; Song, Chul-Yong; Kim, Tong-Soo

    2005-01-01

    Protective efficacy of vaccination with Neospora caninum multiple recombinant antigens against N. caninum infection was evaluated in vitro and in vivo. Two major immunodominant surface antigens (NcSAG1 and NcSRS2) and two dense granule proteins (NcDG1 and NcDG2) of N. caninum tachyzoites were expressed in E. coli, respectively. An in vitro neutralization assay using polyclonal antisera raised against each recombinant antigen showed inhibitory effects on the invasion of N. caninum tachyzoites ...

  14. Experimental Study of Interference Between Pertussis Antigens and Salk Poliomyelitis Vaccine

    Directory of Open Access Journals (Sweden)

    H. Mirehamsy

    1962-01-01

    Full Text Available An interference is observed between whooping-cough antigens and Salk polioc vaccine even if the two components are mixed immediately before use. The phenomenon is more evident when flUlid antigens are injected. Pertussis soluble antigen, which gives a good serological response in rabbits, when used alone or combined with DT, is inactivated in the presence of Salk polio vacc:ne

  15. Investigation of the response to the enterobacterial common antigen after typhoid vaccination

    Directory of Open Access Journals (Sweden)

    Arlete M. Milhomem

    1987-03-01

    Full Text Available Antibodies against the Salmonella typhi enterobacterial common antigen (ECA and the O and H antigens were investigated in sera from healthy male subjects who had been previously vaccinated with the typhoid vaccine. No serological response to ECA was observed. Sera from subjects not previously vaccinated presented titers of ECA hemagglutinins which quantitatively were related to the presence ofH titers, but not to O agglutinins but with no statistical significance. The results are discussed in relation to the possible protective immunological mechanisms in typhoid fever.

  16. Delivery of a multivalent scrambled antigen vaccine induces broad spectrum immunity and protection against tuberculosis.

    Science.gov (United States)

    West, Nicholas P; Thomson, Scott A; Triccas, James A; Medveczky, C Jill; Ramshaw, Ian A; Britton, Warwick J

    2011-10-13

    The development of effective anti-Tuberculosis (TB) vaccines is an important step towards improved control of TB in high burden countries. Subunit vaccines are advantageous in terms of safety, particularly in the context of high rates of HIV co-infection, but they must contain sufficient Mycobacterium tuberculosis antigens to stimulate immunity in genetically diverse human populations. We have used a novel approach to develop a synthetic scrambled antigen vaccine (TB-SAVINE), comprised of overlapping, recombined peptides from four M. tuberculosis proteins, Ag85B, ESAT-6, PstS3 and Mpt83, each of which is immunogenic and protective against experimental TB. This polyvalent TB-SAVINE construct stimulated CD4 and CD8T cell responses against the individual proteins and M. tuberculosis in C57BL/6 and Balb/c mice, when delivered as DNA, Fowl Pox Virus or Vaccinia Virus vaccines. In addition, the DNA-TBS vaccine induced protective immunity against pulmonary M. tuberculosis infection in C57BL/6 mice. Co-immunization of Balb/c mice with virally expressed TBS and HIV1-SAVINE vaccine stimulated strong T cell responses to both the M. tuberculosis and HIV proteins, indicating no effects of antigenic competition. Further development of this TB-SAVINE vaccine expressing components from multiple M. tuberculosis proteins may prove an effective vaccine candidate against TB, which could potentially form part of a safe, combined preventative strategy together with HIV immunisations. PMID:21846485

  17. TH1 and TH2 responses are influenced by HLA antigens in healthy neonates vaccinated with recombinant hepatitis B vaccine.

    Directory of Open Access Journals (Sweden)

    Abdollah Jafarzadeh

    2012-12-01

    Full Text Available The immune response to hepatitis B surface antigen (HBsAg is influenced by several factors, of which HLA antigens and balanced secretion of Th1/Th2 cytokines play important roles. The aim of this study was to evaluate the influence of HLA antigens on cytokine secretion by HBsAg-stimulated peripheral blood mononuclear cells (PBMC from healthy neonates vaccinated with recombinant HBsAg. PBMCs were isolated from 48 Iranian neonates vaccinated with a recombinant HBV vaccine. The cells were stimulated in vitro with rHBsAg and the concentration of IL-4, IL-10, IL-12 and IFN-γ were quantitated in culture supernatant by sandwich ELISA. HLA typing was performed by microlymphocytotoxicity method. Significant diminished secretion of both Th1 (IFN-γ and Th2 (IL-4, IL-10 cytokines was observed in HBsAg-stimulated PBMC from vaccinees expressing the HLA-DR7 compared to DR7 negative vaccinees. Similarly, lower production of these cytokines was also observed in vaccinees with DR7-DR53-DQ2, B7-DR7-DR53-DQ2 and A2-DR7-DR53-DQ2 haplotypes (p<0.05, p <0.005. While HBsAg-stimulated PBMC of DR13+ subjects produced lower levels of Th2-type cytokines (IL-4 and IL-10, those of HLA-B8+ or HLA-A9+ subjects produced higher levels of Th2-type cytokines. Cytokine secretion in response to PHA mitogen was not associated with a given HLA antigen or haplotype and was similarly represented in all groups of subjects irrespective of their HLA complex. These results indicate that HLA antigens may differentially influence cytokine secretion by HBsAg-specific T-cells of healthy neonates vaccinated with recombinant HB vaccine. This phenomenon may have an important implication for control of the immune response to HBsAg vaccine.

  18. Immunogenicity of Mycobacterium tuberculosis Antigens in Mycobacterium bovis BCG-Vaccinated and M. bovis-Infected Cattle

    OpenAIRE

    Mustafa, A. S.; Skeiky, Y A; Al-Attiyah, R.; Alderson, M. R.; Hewinson, R. G.; Vordermeier, H M

    2006-01-01

    The development of novel vaccine strategies supplementing Mycobacterium bovis BCG (BCG) constitutes an urgent research challenge. To identify potential subunit vaccine candidates, we have tested a series of eight recently identified Mycobacterium tuberculosis antigens in M. bovis-infected and BCG-vaccinated cattle. These antigens were characterized on the basis of their ability to induce in vitro gamma interferon responses in infected or BCG-vaccinated calves. We were able to establish a hier...

  19. Real-time PCR analysis of genes encoding tumor antigens in esophageal tumors and a cancer vaccine

    DEFF Research Database (Denmark)

    Weinert, Brian T; Krishnadath, Kausilia K; Milano, Francesca;

    2009-01-01

    Tumor antigens are the primary target of therapeutic cancer vaccines. We set out to define and compare the expression pattern of tumor antigen genes in esophagus carcinoma biopsies and in an allogeneic tumor lysate-based cancer vaccine, MelCancerVac. Cells used for vaccine production were treated...... the production of the vaccine. Quantitative PCR was used to assay 74 tumor antigen genes in patients with squamous cell carcinoma of the esophagus. 81% (13/16) of tumors expressed more than five cancer/testis (CT) antigens. A total of 96 genes were assayed in the tumor cell clone (DDM1.7) used to make...

  20. Controlled and targeted release of antigens by intelligent shell for improving applicability of oral vaccines.

    Science.gov (United States)

    Zhang, Lei; Zeng, Zhanzhuang; Hu, Chaohua; Bellis, Susan L; Yang, Wendi; Su, Yintao; Zhang, Xinyan; Wu, Yunkun

    2016-01-01

    Conventional oral vaccines with simple architecture face barriers with regard to stimulating effective immunity. Here we describe oral vaccines with an intelligent phase-transitional shielding layer, poly[(methyl methacrylate)-co-(methyl acrylate)-co-(methacrylic acid)]-poly(D,L-lactide-co-glycolide) (PMMMA-PLGA), which can protect antigens in the gastro-intestinal tract and achieve targeted vaccination in the large intestine. With the surface immunogenic protein (SIP) from group B Streptococcus (GBS) entrapped as the antigen, oral administration with PMMMA-PLGA (PTRBL)/Trx-SIP nanoparticles stimulated robust immunity in tilapia, an animal with a relatively simple immune system. The vaccine succeeded in protecting against Streptococcus agalactiae, a pathogen of worldwide importance that threatens human health and is transmitted in water with infected fish. After oral vaccination with PTRBL/Trx-SIP, tilapia produced enhanced levels of SIP specific antibodies and displayed durability of immune protection. 100% of the vaccinated tilapia were protected from GBS infection, whereas the control groups without vaccines or vaccinated with Trx-SIP only exhibited respective infection rates of 100% or >60% within the initial 5 months after primary vaccination. Experiments in vivo demonstrated that the recombinant antigen Trx-SIP labeled with FITC was localized in colon, spleen and kidney, which are critical sites for mounting an immune response. Our results revealed that, rather than the size of the nanoparticles, it is more likely that the negative charge repulsion produced by ionization of the carboxyl groups in PMMMA shielded the nanoparticles from uptake by small intestinal epithelial cells. This system resolves challenges arising from gastrointestinal damage to antigens, and more importantly, offers a new approach applicable for oral vaccination. PMID:26624805

  1. CD8+ T cell priming by dendritic cell vaccines requires antigen transfer to endogenous antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Alice W Yewdall

    Full Text Available Immunotherapeutic strategies to stimulate anti-tumor immunity are promising approaches for cancer treatment. A major barrier to their success is the immunosuppressive microenvironment of tumors, which inhibits the functions of endogenous dendritic cells (DCs that are necessary for the generation of anti-tumor CD8+ T cells. To overcome this problem, autologous DCs are generated ex vivo, loaded with tumor antigens, and activated in this non-suppressive environment before administration to patients. However, DC-based vaccines rarely induce tumor regression.We examined the fate and function of these DCs following their injection using murine models, in order to better understand their interaction with the host immune system. Contrary to previous assumptions, we show that DC vaccines have an insignificant role in directly priming CD8+ T cells, but instead function primarily as vehicles for transferring antigens to endogenous antigen presenting cells, which are responsible for the subsequent activation of T cells.This reliance on endogenous immune cells may explain the limited success of current DC vaccines to treat cancer and offers new insight into how these therapies can be improved. Future approaches should focus on creating DC vaccines that are more effective at directly priming T cells, or abrogating the tumor induced suppression of endogenous DCs.

  2. Assessing the relationship between antigenicity and immunogenicity of human rabies vaccines when administered by intradermal route

    Science.gov (United States)

    Bilagumba, Gangaboraiah; Ravish, Haradanahalli Shankarappa; Narayana, Hanumanthappa Ashwath Doddabele

    2010-01-01

    The metadata of 10 published studies and 3 vaccine trial reports comprising of 19 vaccine cohorts from four countries conducted over a period of 23 years (1986–2009) was used for metaanalysis. The vaccines studied were purified chick embryo cell vaccine (Rabipur, India and Germany), purified vero cell rabies vaccine (Verorab, France; Indirab, India) and human diploid cell vaccine (MIRV, France). The potency of these vaccines varied from 0.55 IU to 2.32 IU per intradermal dose of 0.1 ml per site. The vaccines were administered to 1,011 subjects comprising of 19 cohorts and using five different ID regimens. The immunogenicity was measured by assays of rabies virus neutralizing antibody (RVNA) titres using rapid fluorescent focus inhibition test (RFFIT) [15 cohorts] and mouse neutralization test (MNT) [4 cohorts]. The statistical analysis of the data was done by Karl Pearson's correlation coefficient to measure the relationship between antigenicity and immunogenicity. It was revealed that, there was no significant linear relationship between antigenicity and immunogenicity of rabies vaccines when administered by intradermal route (p > 0.230 and p > 0.568). PMID:20523131

  3. Optimized tumor cryptic peptides: the basis for universal neo-antigen-like tumor vaccines.

    Science.gov (United States)

    Menez-Jamet, Jeanne; Gallou, Catherine; Rougeot, Aude; Kosmatopoulos, Kostas

    2016-07-01

    The very impressive clinical results recently obtained in cancer patients treated with immune response checkpoint inhibitors boosted the interest in immunotherapy as a therapeutic choice in cancer treatment. However, these inhibitors require a pre-existing tumor specific immune response and the presence of tumor infiltrating T cells to be efficient. This immune response can be triggered by cancer vaccines. One of the main issues in tumor vaccination is the choice of the right antigen to target. All vaccines tested to date targeted tumor associated antigens (TAA) that are self-antigens and failed to show a clinical efficacy because of the immune self-tolerance to TAA. A new class of tumor antigens has recently been described, the neo-antigens that are created by point mutations of tumor expressing proteins and are recognized by the immune system as non-self. Neo-antigens exhibit two main properties: they are not involved in the immune self-tolerance process and are immunogenic. However, the majority of the neo-antigens are patient specific and their use as cancer vaccines requires their previous identification in each patient individualy that can be done only in highly specialized research centers. It is therefore evident that neo-antigens cannot be used for patient vaccination worldwide. This raises the question of whether we can find neo-antigen like vaccines, which would not be patient specific. In this review we show that optimized cryptic peptides from TAA are neo-antigen like peptides. Optimized cryptic peptides are recognized by the immune system as non-self because they target self-cryptic peptides that escape self-tolerance; in addition they are strongly immunogenic because their sequence is modified in order to enhance their affinity for the HLA molecule. The first vaccine based on the optimized cryptic peptide approach, Vx-001, which targets the widely expressed tumor antigen telomerase reverse transcriptase (TERT), has completed a large phase I clinical

  4. Intra-dermal administration of rabies vaccines in developing countries: at an affordable cost.

    Science.gov (United States)

    Verma, Ramesh; Khanna, Pardeep; Prinja, Shankar; Rajput, Meena

    2011-07-01

    Rabies is a virtually 100% fatal acute viral encephalitis. Rabies occurs in more than 150 countries and territories. Globally there are 17.4 million animal bite cases and more than 55,000 deaths annually. India's 20,000 deaths accounts for 36% of global and 65% of the Asian (31,000) deaths. The Intradermal Rabies Vaccine (IDRV) was first started in Thailand in 1984. In 1992, World Health Organization approved it for use in developing countries which face a shortage of rabies vaccine due to paucity of funds. Vaccines like Purified Vero cell vaccine (PVRV), Purified chick embryo cell vaccine (PCECV) and Human diploid cell vaccine (HDCV) that can be injected by the intradermal route for Post Exposure Prophylaxis as approved by WHO. The regimen approved by the WHO/DCGI India is the Updated Thai Red Cross Regimen, which involves injection of 0.1 mL of reconstituted vaccine per ID site and on two such ID site per visit on Days 0, 3, 7 and 28 (2-2-2-0-2). All reconstituted vaccine unused at the end of 6-8 h must be discarded. The ID route is ideal in terms of economic benefits, safety and efficacy. This reduces the cost of vaccination by about 68%, which is clearly an attractive option for resource-starved countries like India. PMID:21734465

  5. MHC-restricted antigen presentation and recognition: constraints on gene, recombinant and peptide vaccines in humans

    Directory of Open Access Journals (Sweden)

    Cunha-Neto E.

    1999-01-01

    Full Text Available The target of any immunization is to activate and expand lymphocyte clones with the desired recognition specificity and the necessary effector functions. In gene, recombinant and peptide vaccines, the immunogen is a single protein or a small assembly of epitopes from antigenic proteins. Since most immune responses against protein and peptide antigens are T-cell dependent, the molecular target of such vaccines is to generate at least 50-100 complexes between MHC molecule and the antigenic peptide per antigen-presenting cell, sensitizing a T cell population of appropriate clonal size and effector characteristics. Thus, the immunobiology of antigen recognition by T cells must be taken into account when designing new generation peptide- or gene-based vaccines. Since T cell recognition is MHC-restricted, and given the wide polymorphism of the different MHC molecules, distinct epitopes may be recognized by different individuals in the population. Therefore, the issue of whether immunization will be effective in inducing a protective immune response, covering the entire target population, becomes an important question. Many pathogens have evolved molecular mechanisms to escape recognition by the immune system by variation of antigenic protein sequences. In this short review, we will discuss the several concepts related to selection of amino acid sequences to be included in DNA and peptide vaccines.

  6. Co-administration of certain DNA vaccine combinations expressing different H5N1 influenza virus antigens can be beneficial or detrimental to immune protection.

    Science.gov (United States)

    Patel, Ami; Gray, Michael; Li, Yan; Kobasa, Darwyn; Yao, Xiaojian; Kobinger, Gary P

    2012-01-11

    Achieving broad-spectrum immunity against emerging zoonotic viruses such as avian influenza H5N1 and other possible pandemic viruses will require generation of cross-protective immune responses. Strong antibody responses generated against the H5HA protein are protective, however, antigenic variation between diverging isolates can interfere with virus neutralization. The current study investigates co-administration of an H5 HA DNA vaccine with other variable and conserved influenza antigens (NA, NP, and M2). All antigens were derived from the A/Hanoi/30408/2005 (H5N1) virus and the contribution towards overall protection and immune activation was assessed against lethal homologous and heterologous challenges. An (HA+NA) combination afforded the best protection against homologous challenge and (HA+NP) was comparable to HA alone against heterologous A/Hong Kong/483/1997 challenge. Interestingly, combining all four H5 antigens at a single site did not improve protection against matched challenge and unexpectedly reduced survival by 30% against a heterologous challenge. Survival was also significantly decreased against heterologous challenge following combination of (HA+NP) with an unrelated antigen. Although there were no significant changes in antibody titres, significantly lower T-cell responses were detected against all antigens except HA in each combination. Co-administration of the vaccines at different injection sites restored T-cell responses but did not improve overall protection. Similar observations were also recorded following combination of HA and NP antigens using two different adenovirus-based backbones. Overall, the data suggest that co-administering certain H5N1 antigens offer better or comparable protection to HA alone, however, combining extra antigens may be unnecessary and lead to unfavourable immune responses. PMID:22119588

  7. Comparative vaccination of cattle against Boophilus microplus with recombinant antigen Bm86 alone or in combination with recombinant Bm91.

    Science.gov (United States)

    Willadsen, P; Smith, D; Cobon, G; McKenna, R V

    1996-05-01

    Cattle were vaccinated either with a single recombinant tick antigen, Bm86 or with a combination of two recombinant antigens, Bm86 and Bm91 from the tick Boophilus microplus. In three experiments, the responses of cattle to subsequent challenge with the tick were assessed. The addition of the Bm91 antigen enhanced the efficacy of the vaccination over that with Bm86 alone to a statistically significant degree. Moreover, co-vaccination with two antigens did not impair the response of cattle to the Bm86 antigen. Finally, responses of individual cattle to the two antigens were independent. All of these results may be relevant to the increase in efficacy expected from a dual antigen vaccine. PMID:9229376

  8. Bacterial Antigen Expression Is an Important Component in Inducing an Immune Response to Orally Administered Salmonella-Delivered DNA Vaccines

    OpenAIRE

    Gahan, Michelle E.; Webster, Diane E.; Wesselingh, Steven L.; Richard A. Strugnell; Yang, Ji

    2009-01-01

    Background The use of Salmonella to deliver heterologous antigens from DNA vaccines is a well-accepted extension of the success of oral Salmonella vaccines in animal models. Attenuated S. typhimurium and S. typhi strains are safe and efficacious, and their use to deliver DNA vaccines combines the advantages of both vaccine approaches, while complementing the limitations of each technology. An important aspect of the basic biology of the Salmonella/DNA vaccine platform is the relative contribu...

  9. Vaccination of Rhesus Macaques with the Anthrax Vaccine Adsorbed Vaccine Produces a Serum Antibody Response That Effectively Neutralizes Receptor-Bound Protective Antigen In Vitro ▿

    OpenAIRE

    Clement, Kristin H.; Rudge, Thomas L.; Mayfield, Heather J.; Carlton, Lena A.; Hester, Arelis; Niemuth, Nancy A.; Sabourin, Carol L.; Brys, April M.; Quinn, Conrad P.

    2010-01-01

    Anthrax toxin (ATx) is composed of the binary exotoxins lethal toxin (LTx) and edema toxin (ETx). They have separate effector proteins (edema factor and lethal factor) but have the same binding protein, protective antigen (PA). PA is the primary immunogen in the current licensed vaccine anthrax vaccine adsorbed (AVA [BioThrax]). AVA confers protective immunity by stimulating production of ATx-neutralizing antibodies, which could block the intoxication process at several steps (binding of PA t...

  10. Human Leukocyte Antigens Influence the Antibody Response to Hepatitis B Vaccine

    OpenAIRE

    Abdollah Jafarzadeh; Masoome Bagheri-Jamebozorgi; Maryam Nemati; Forough Golsaz-Shirazi; Fazel Shokri

    2015-01-01

    Hepatitis B virus (HBV) infection and its sequelae such as cirrhosis and hepatocellular carcinoma has remained a serious public health problem throughout the world. The WHO strategy for effective control of HBV infection and its complications is mass vaccination of neonates and children within the framework of Expanded Programme on Immunization (EPI). Vaccination with hepatitis B surface antigen (HBsAg) induces protective antibody response (anti-HBs ≥ 10 IU/L) in 90-99% of vaccinees.The lack ...

  11. Pros and Cons of Antigen-Presenting Cell Targeted Tumor Vaccines

    Directory of Open Access Journals (Sweden)

    Cleo Goyvaerts

    2015-01-01

    Full Text Available In therapeutic antitumor vaccination, dendritic cells play the leading role since they decide if, how, when, and where a potent antitumor immune response will take place. Since the disentanglement of the complexity and merit of different antigen-presenting cell subtypes, antitumor immunotherapeutic research started to investigate the potential benefit of targeting these subtypes in situ. This review will discuss which antigen-presenting cell subtypes are at play and how they have been targeted and finally question the true meaning of targeting antitumor-based vaccines.

  12. Sulfate-binding protein, CysP, is a candidate vaccine antigen of Moraxella catarrhalis.

    Science.gov (United States)

    Murphy, Timothy F; Kirkham, Charmaine; Johnson, Antoinette; Brauer, Aimee L; Koszelak-Rosenblum, Mary; Malkowski, Michael G

    2016-07-19

    Moraxella catarrhalis causes otitis media in children and respiratory tract infections in adults with chronic obstructive pulmonary disease (COPD). A vaccine to prevent M. catarrhalis infections would have an enormous impact globally in preventing morbidity caused by M. catarrhalis in these populations. Using a genome mining approach we have identified a sulfate binding protein, CysP, of an ATP binding cassette (ABC) transporter system as a novel candidate vaccine antigen. CysP expresses epitopes on the bacterial surface and is highly conserved among strains. Immunization with CysP induces potentially protective immune responses in a murine pulmonary clearance model. In view of these features that indicate CysP is a promising vaccine antigen, we conducted further studies to elucidate its function. These studies demonstrated that CysP binds sulfate and thiosulfate ions, plays a nutritional role for the organism and functions in intracellular survival of M. catarrhalis in human respiratory epithelial cells. The observations that CysP has features of a vaccine antigen and also plays an important role in growth and survival of the organism indicate that CysP is an excellent candidate vaccine antigen to prevent M. catarrhalis otitis media and infections in adults with COPD. PMID:27265455

  13. Strategic evaluation of vaccine candidate antigens for the prevention of Visceral Leishmaniasis.

    Science.gov (United States)

    Duthie, Malcolm S; Favila, Michelle; Hofmeyer, Kimberley A; Tutterrow, Yeung L; Reed, Steven J; Laurance, John D; Picone, Alessandro; Guderian, Jeffrey; Bailor, H Remy; Vallur, Aarthy C; Liang, Hong; Mohamath, Raodoh; Vergara, Julie; Howard, Randall F; Coler, Rhea N; Reed, Steven G

    2016-05-27

    Infection with Leishmania parasites results in a range of clinical manifestations and outcomes, the most severe of which is visceral leishmaniasis (VL). Vaccination will likely provide the most effective long-term control strategy, as the large number of vectors and potential infectious reservoirs renders sustained interruption of Leishmania parasite transmission extremely difficult. Selection of the best vaccine is complicated because, although several vaccine antigen candidates have been proposed, they have emerged following production in different platforms. To consolidate the information that has been generated into a single vaccine platform, we expressed seven candidates as recombinant proteins in E. coli. After verifying that each recombinant protein could be recognized by VL patients, we evaluated their protective efficacy against experimental L. donovani infection of mice. Administration in formulation with the Th1-potentiating adjuvant GLA-SE indicated that each antigen could elicit antigen-specific Th1 responses that were protective. Considering the ability to reduce parasite burden along with additional factors such as sequence identity across Leishmania species, we then generated a chimeric fusion protein comprising a combination of the 8E, p21 and SMT proteins. This E. coli -expressed fusion protein was also demonstrated to protect against L. donovani infection. These data indicate a novel recombinant vaccine antigen with the potential for use in VL control programs. PMID:27142329

  14. Immunological control of ticks through vaccination with Boophilus microplus gut antigens.

    Science.gov (United States)

    De La Fuente, J; Rodríguez, M; García-García, J C

    2000-01-01

    The control of tick infestations and the transmission of tick-borne diseases remain a challenge for the scientific community. Traditional control methods have been only partially successful. Recently, vaccination with recombinant Boophilus microplus gut antigens has been shown to control tick infestations. Our Bm86-containing vaccine formulation (Gavac) has been effective for the control of artificial infestations of B. annulatus, B. decoloratus, and chemically sensitive and resistant B. microplus strains from Australia, Africa, America, and Iran. Preliminary results with Hyalomma spp. and Rhipicephalus spp. suggest partial cross protection. In field trials, vaccination with Gavac controlled B. microplus and B. annulatus infestations and reduced the transmission of babesiosis, resulting in important savings for the cattle industry. Different degrees of susceptibility to the vaccination with Bm86 and sequence variations in the Bm86 locus have been reported. The Bm95 antigen was isolated from the Argentinean Bm86-resistant B. microplus strain A. A Bm95-based vaccine was used to protect cattle against tick infestations under production conditions with similar results to that obtained with Gavac. The Bm95 antigen from strain A was able to protect against infestations with Bm86-sensitive and Bm86-resistant tick strains, thus suggesting that Bm95 could be a more universal antigen in protecting cattle against infestations by B. microplus strains from different geographical areas. These results clearly demonstrate the advantage and possibilities for the immunological control of ticks. PMID:11193686

  15. Successful vaccination with a polyvalent live vector despite existing immunity to an expressed antigen.

    Science.gov (United States)

    Flexner, C; Murphy, B R; Rooney, J F; Wohlenberg, C; Yuferov, V; Notkins, A L; Moss, B

    1988-09-15

    A global vaccination strategy must take into account production and delivery costs as well as efficacy and safety. A heat-stable, polyvalent vaccine that requires only one inoculation and induces a high level of humoral and cellular immunity against several diseases is therefore desirable. A new approach is to use live microorganisms such as mycobacteria, enteric bacteria, adenoviruses, herpesviruses and poxviruses as vaccine vectors. A potential limitation of live polyvalent vaccines, however, is existing immunity within the target population not only to the vector, but to any of the expressed antigens. This could restrict replication of the vector, curtail expression of antigens, and reduce the total immune response to the vaccine. Recently acquired immunity to vaccinia virus can severely limit the efficacy of a live recombinant vaccinia-based vaccine, so a strategy involving closely spaced inoculations with the same vector expressing different antigens may present difficulties. We have constructed a recombinant vaccinia virus that expresses surface proteins from two diverse pathogens, influenza A virus haemagglutinin and herpes simplex virus type 1 (HSV-1) glycoprotein D. Mice that had recently recovered from infection with either HSV-1 or influenza A virus could still be effectively immunized with the double recombinant. PMID:2842693

  16. Scaffolded Antigens in Yeast Cell Particle Vaccines Provide Protection against Systemic Polyoma Virus Infection.

    Science.gov (United States)

    Tipper, Donald J; Szomolanyi-Tsuda, Eva

    2016-01-01

    Background. U65, a self-aggregating peptide scaffold, traps fused protein antigens in yeast cells. Conversion to Yeast Cell Particle (YCP) vaccines by partial removal of surface mannoproteins exposes β-glucan, mediating efficient uptake by antigen-presenting cells (APCs). YCP vaccines are inexpensive, capable of rapid large-scale production and have potential for both parenteral and oral use. Results. YCP processing by alkaline hydrolysis exposes up to 20% of the glucan but converts scaffolded antigen and internal yeast proteins into a common aggregate, preventing selective yeast protein removal. For U65-green fluorescent protein (GFP) or U65-Apolipoprotein A1 (ApoA1) subcutaneous vaccines, maximal IgG responses in mice required 10% glucan exposure. IgG responses to yeast proteins were 5-fold lower. Proteolytic mannoprotein removal produced YCPs with only 6% glucan exposure, insufficiently porous for selective removal of even native yeast proteins. Vaccine efficacy was reduced 10-fold. Current YCP formulations, therefore, are not suitable for human use but have considerable potential for use in feed animal vaccines. Significantly, a YCP vaccine expressing a GFP fusion to VP1, the murine polyoma virus major capsid protein, after either oral or subcutaneous administration, protected mice against an intraperitoneal polyoma virus challenge, reducing viral DNA levels in spleen and liver by >98%. PMID:27213160

  17. Scaffolded Antigens in Yeast Cell Particle Vaccines Provide Protection against Systemic Polyoma Virus Infection

    Directory of Open Access Journals (Sweden)

    Donald J. Tipper

    2016-01-01

    Full Text Available Background. U65, a self-aggregating peptide scaffold, traps fused protein antigens in yeast cells. Conversion to Yeast Cell Particle (YCP vaccines by partial removal of surface mannoproteins exposes β-glucan, mediating efficient uptake by antigen-presenting cells (APCs. YCP vaccines are inexpensive, capable of rapid large-scale production and have potential for both parenteral and oral use. Results. YCP processing by alkaline hydrolysis exposes up to 20% of the glucan but converts scaffolded antigen and internal yeast proteins into a common aggregate, preventing selective yeast protein removal. For U65-green fluorescent protein (GFP or U65-Apolipoprotein A1 (ApoA1 subcutaneous vaccines, maximal IgG responses in mice required 10% glucan exposure. IgG responses to yeast proteins were 5-fold lower. Proteolytic mannoprotein removal produced YCPs with only 6% glucan exposure, insufficiently porous for selective removal of even native yeast proteins. Vaccine efficacy was reduced 10-fold. Current YCP formulations, therefore, are not suitable for human use but have considerable potential for use in feed animal vaccines. Significantly, a YCP vaccine expressing a GFP fusion to VP1, the murine polyoma virus major capsid protein, after either oral or subcutaneous administration, protected mice against an intraperitoneal polyoma virus challenge, reducing viral DNA levels in spleen and liver by >98%.

  18. Scaffolded Antigens in Yeast Cell Particle Vaccines Provide Protection against Systemic Polyoma Virus Infection

    Science.gov (United States)

    Tipper, Donald J.; Szomolanyi-Tsuda, Eva

    2016-01-01

    Background. U65, a self-aggregating peptide scaffold, traps fused protein antigens in yeast cells. Conversion to Yeast Cell Particle (YCP) vaccines by partial removal of surface mannoproteins exposes β-glucan, mediating efficient uptake by antigen-presenting cells (APCs). YCP vaccines are inexpensive, capable of rapid large-scale production and have potential for both parenteral and oral use. Results. YCP processing by alkaline hydrolysis exposes up to 20% of the glucan but converts scaffolded antigen and internal yeast proteins into a common aggregate, preventing selective yeast protein removal. For U65-green fluorescent protein (GFP) or U65-Apolipoprotein A1 (ApoA1) subcutaneous vaccines, maximal IgG responses in mice required 10% glucan exposure. IgG responses to yeast proteins were 5-fold lower. Proteolytic mannoprotein removal produced YCPs with only 6% glucan exposure, insufficiently porous for selective removal of even native yeast proteins. Vaccine efficacy was reduced 10-fold. Current YCP formulations, therefore, are not suitable for human use but have considerable potential for use in feed animal vaccines. Significantly, a YCP vaccine expressing a GFP fusion to VP1, the murine polyoma virus major capsid protein, after either oral or subcutaneous administration, protected mice against an intraperitoneal polyoma virus challenge, reducing viral DNA levels in spleen and liver by >98%.

  19. Potential Target Antigens for a Universal Vaccine in Epithelial Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Renee Vermeij

    2010-01-01

    Full Text Available The prognosis of epithelial ovarian cancer (EOC, the primary cause of death from gynaecological malignancies, has only modestly improved over the last decades. Immunotherapeutic treatment using a cocktail of antigens has been proposed as a “universal” vaccine strategy. We determined the expression of tumor antigens in the context of MHC class I expression in 270 primary tumor samples using tissue microarray. Expression of tumor antigens p53, SP17, survivin, WT1, and NY-ESO-1 was observed in 120 (48.0%, 173 (68.9%, 208 (90.0%, 129 (56.3%, and 27 (11.0% of 270 tumor specimens, respectively. In 93.2% of EOC, at least one of the investigated tumor antigens was (overexpressed. Expression of MHC class I was observed in 78.1% of EOC. In 3 out 4 primary tumors, (overexpression of a tumor antigen combined with MHC class I was observed. These results indicate that a multiepitope vaccine, comprising these antigens, could serve as a universal therapeutic vaccine for the vast majority of ovarian cancer patients.

  20. A Francisella tularensis live vaccine strain that improves stimulation of antigen-presenting cells does not enhance vaccine efficacy.

    Directory of Open Access Journals (Sweden)

    Deanna M Schmitt

    Full Text Available Vaccination is a proven strategy to mitigate morbidity and mortality of infectious diseases. The methodology of identifying and testing new vaccine candidates could be improved with rational design and in vitro testing prior to animal experimentation. The tularemia vaccine, Francisella tularensis live vaccine strain (LVS, does not elicit complete protection against lethal challenge with a virulent type A Francisella strain. One factor that may contribute to this poor performance is limited stimulation of antigen-presenting cells. In this study, we examined whether the interaction of genetically modified LVS strains with human antigen-presenting cells correlated with effectiveness as tularemia vaccine candidates. Human dendritic cells infected with wild-type LVS secrete low levels of proinflammatory cytokines, fail to upregulate costimulatory molecules, and activate human T cells poorly in vitro. One LVS mutant, strain 13B47, stimulated higher levels of proinflammatory cytokines from dendritic cells and macrophages and increased costimulatory molecule expression on dendritic cells compared to wild type. Additionally, 13B47-infected dendritic cells activated T cells more efficiently than LVS-infected cells. A deletion allele of the same gene in LVS displayed similar in vitro characteristics, but vaccination with this strain did not improve survival after challenge with a virulent Francisella strain. In vivo, this mutant was attenuated for growth and did not stimulate T cell responses in the lung comparable to wild type. Therefore, stimulation of antigen-presenting cells in vitro was improved by genetic modification of LVS, but did not correlate with efficacy against challenge in vivo within this model system.

  1. Epitope-based recombinant diagnostic antigen to distinguish natural infection from vaccination with hepatitis A virus vaccines.

    Science.gov (United States)

    Su, Qiudong; Guo, Minzhuo; Jia, Zhiyuan; Qiu, Feng; Lu, Xuexin; Gao, Yan; Meng, Qingling; Tian, Ruiguang; Bi, Shengli; Yi, Yao

    2016-07-01

    Hepatitis A virus (HAV) infection can stimulate the production of antibodies to structural and non-structural proteins of the virus. However, vaccination with an inactivated or attenuated HAV vaccine produces antibodies mainly against structural proteins, whereas no or very limited antibodies are produced against the non-structural proteins. Current diagnostic assays to determine exposure to HAV, such as the Abbott HAV AB test, detect antibodies only to the structural proteins and so are not able to distinguish a natural infection from vaccination with an inactivated or attenuated virus. Here, we constructed a recombinant tandem multi-epitope diagnostic antigen (designated 'H1') based on the immune-dominant epitopes of the non-structural proteins of HAV to distinguish the two situations. H1 protein expressed in Escherichia coli and purified by affinity and anion exchange chromatography was applied in a double-antigen sandwich ELISA for the detection of anti-non-structural HAV proteins, which was confirmed to distinguish a natural infection from vaccination with an inactivated or attenuated HAV vaccine. PMID:26994964

  2. Antigenic glycans in parasitic infections: implications for vaccines and diagnostics.

    Science.gov (United States)

    Nyame, A Kwame; Kawar, Ziad S; Cummings, Richard D

    2004-06-15

    Infections by parasitic protozoans and helminths are a major world-wide health concern, but no vaccines exist to the major human parasitic diseases, such as malaria, African trypanosomiasis, amebiasis, leishmaniasis, schistosomiasis, and lymphatic filariasis. Recent studies on a number of parasites indicate that immune responses to parasites in infected animals and humans are directed to glycan determinants within cell surface and secreted glycoconjugates and that glycoconjugates are important in host-parasite interactions. Because of the tremendous success achieved recently in generating carbohydrate-protein conjugate vaccines toward microbial infections, such as Haemophilus influenzae type b, there is renewed interest in defining parasite-derived glycans in the prospect of developing conjugate vaccines and new diagnostics for parasitic infections. Parasite-derived glycans are compelling vaccine targets because they have structural features that distinguish them from mammalian glycans. There have been exciting new developments in techniques for glycan analysis and the methods for synthesizing oligosaccharides by chemical or combined chemo-enzymatic approaches that now make it feasible to generate parasite glycans to test as vaccine candidates. Here, we highlight recent progress made in elucidating the immunogenicity of glycans from some of the major human and animal parasites, the potential for developing conjugate vaccines for parasitic infections, and the possible utilization of these novel glycans in diagnostics. PMID:15158669

  3. mTOR inhibition improves antitumor effects of vaccination with antigen-encoding RNA.

    Science.gov (United States)

    Diken, Mustafa; Kreiter, Sebastian; Vascotto, Fulvia; Selmi, Abderraouf; Attig, Sebastian; Diekmann, Jan; Huber, Christoph; Türeci, Özlem; Sahin, Ugur

    2013-12-01

    Vaccination with in vitro transcribed RNA encoding tumor antigens is an emerging approach in cancer immunotherapy. Attempting to further improve RNA vaccine efficacy, we have explored combining RNA with immunomodulators such as rapamycin. Rapamycin, the inhibitor of mTOR, was used originally for immunosuppression. Recent reports in mouse systems, however, suggest that mTOR inhibition may enhance the formation and differentiation of the memory CD8(+) T-cell pool. Because memory T-cell formation is critical to the outcome of vaccination approaches, we studied the impact of rapamycin on the in vivo primed RNA vaccine-induced immune response using the chicken ovalbumin-expressing B16 melanoma model in C57BL/6 mice. Our data show that treatment with rapamycin at the effector-to-memory transition phase skews the vaccine-induced immune response toward the formation of a quantitatively and qualitatively superior memory pool and results in a better recall response. Tumor-infiltrating immune cells from these mice display a favorable ratio of effector versus suppressor cell populations. Survival of mice treated with the combined regimen of RNA vaccination with rapamycin is significantly longer (91.5 days) than that in the control groups receiving only one of these compounds (32 and 46 days, respectively). Our findings indicate that rapamycin enhances therapeutic efficacy of antigen-specific CD8(+) T cells induced by RNA vaccination, and we propose further clinical exploration of rapamycin as a component of immunotherapeutic regimens. PMID:24778131

  4. Transcription factor Fos-related antigen 1 is an effective target for a breast cancer vaccine

    Science.gov (United States)

    Luo, Yunping; Zhou, He; Mizutani, Masato; Mizutani, Noriko; Reisfeld, Ralph A.; Xiang, Rong

    2003-07-01

    Protection against breast cancer was achieved with a DNA vaccine against murine transcription factor Fos-related antigen 1, which is overexpressed in aggressively proliferating D2F2 murine breast carcinoma. Growth of primary s.c. tumor and dissemination of pulmonary metastases was markedly suppressed by this oral DNA vaccine, carried by attenuated Salmonella typhimurium, encoding murine Fos-related antigen 1, fused with mutant polyubiquitin, and cotransformed with secretory murine IL-18. The life span of 60% of vaccinated mice was tripled in the absence of detectable tumor growth after lethal tumor cell challenge. Immunological mechanisms involved activation of T, natural killer, and dendritic cells, as indicated by up-regulation of their activation markers and costimulatory molecules. Markedly increased specific target cell lysis was mediated by both MHC class I-restricted CD8+ T cells and natural killer cells isolated from splenocytes of vaccinated mice, including a significant release of proinflammatory cytokines IFN- and IL-2. Importantly, fluorescence analysis of fibroblast growth factor 2 and tumor cell-induced vessel growth in Matrigel plugs demonstrated marked suppression of angiogenesis only in vaccinated animals. Taken together, this multifunctional DNA vaccine proved effective in protecting against growth and metastases of breast cancer by combining the action of immune effector cells with suppression of tumor angiogenesis. vaccine | tumor | metastases | antiangiogenesis

  5. Enhanced immunogenicity of DNA fusion vaccine encoding secreted hepatitis B surface antigen and chemokine RANTES

    International Nuclear Information System (INIS)

    To increase the potency of DNA vaccines, we constructed genetic fusion vaccines encoding antigen, secretion signal, and/or chemokine RANTES. The DNA vaccines encoding secreted hepatitis B surface antigen (HBsAg) were constructed by inserting HBsAg gene into an expression vector with an endoplasmic reticulum (ER)-targeting secretory signal sequence. The plasmid encoding secretory HBsAg (pER/HBs) was fused to cDNA of RANTES, generating pER/HBs/R. For comparison, HBsAg genes were cloned into pVAX1 vector with no signal sequence (pHBs), and further linked to the N-terminus of RANTES (pHBs/R). Immunofluorescence study showed the cytoplasmic localization of HBsAg protein expressed from pHBs and pHBs/R, but not from pER/HBs and pER/HBs/R at 48 h after transfection. In mice, RANTES-fused DNA vaccines more effectively elicited the levels of HBsAg-specific IgG antibodies than pHBs. All the DNA vaccines induced higher levels of IgG2a rather than IgG1 antibodies. Of RANTES-fused vaccines, pER/HBs/R encoding the secreted fusion protein revealed much higher humoral and CD8+ T cell-stimulating responses compared to pHBs/R. These results suggest that the immunogenicity of DNA vaccines could be enhanced by genetic fusion to a secretory signal peptide sequence and RANTES

  6. Combined Reduced-Antigen Content Tetanus, Diphtheria, and Acellular Pertussis (Tdap) Vaccine-Related Erythema Nodosum: Case Report and Review of Vaccine-Associated Erythema Nodosum

    OpenAIRE

    Cohen, Philip R.

    2013-01-01

    Background Vaccination programs reduce the morbidity and mortality of diphtheria, pertussis, and tetanus. Erythema nodosum is a reactive erythema that can be associated with infections, drugs, and many conditions. The new onset of erythema nodosum after receiving vaccination is uncommon. Purpose Combined reduced-antigen content tetanus, diphtheria, and acellular pertussis (Tdap) vaccine-associated erythema nodosum is described and the reports of vaccine-related erythema nodosum are summarized...

  7. Combination of Two Candidate Subunit Vaccine Antigens Elicits Protective Immunity to Ricin and Anthrax Toxin in Mice

    OpenAIRE

    David J Vance; Rong, Yinghui; Brey, Robert N.; Mantis, Nicholas J.

    2014-01-01

    In an effort to develop combination vaccines for biodefense, we evaluated a ricin subunit antigen, RiVax, given in conjunction with an anthrax protective antigen, DNI. The combination led to high endpoint titer antibody response, neutralizing antibodies, and protective immunity against ricin and anthrax lethal toxin. This is a natural combination vaccine, since both antigens are recombinant subunit proteins that would be given to the same target population.

  8. Combination of two candidate subunit vaccine antigens elicits protective immunity to ricin and anthrax toxin in mice.

    Science.gov (United States)

    Vance, David J; Rong, Yinghui; Brey, Robert N; Mantis, Nicholas J

    2015-01-01

    In an effort to develop combination vaccines for biodefense, we evaluated a ricin subunit antigen, RiVax, given in conjunction with an anthrax protective antigen, DNI. The combination led to high endpoint titer antibody response, neutralizing antibodies, and protective immunity against ricin and anthrax lethal toxin. This is a natural combination vaccine, since both antigens are recombinant subunit proteins that would be given to the same target population. PMID:25475957

  9. HA03 as an Iranian Candidate Concealed Antigen for Vaccination against Hyalomma anatolicum anatolicum: Comparative Structural and In silico Studies

    OpenAIRE

    Mohammadi, A.; Aghaiypour, K; Keywanfar, H.; Paykari, H.,; Tajbakhsh, H.; Jalali, A.H.,; Safavieh, S.; Foroghi, A.

    2013-01-01

    In the last decades researchers had focused on developing a vaccine against tick based on protective antigen. Recombinant vaccines based on concealed antigen from Boophilus microplus have been developed in Australia and Cuba by the name of TICKGARD and GAVAC (De La Fuente and Kocan, 2006). Further studies on this antigen have shown some extent of protection against other species (De Vos et al., 2001). In Iran most important species is Hyalomma anatolicum and limited information about its cont...

  10. Immunogenicity in mice and rabbits of DNA vaccines expressing woodchuck hepatitis virus antigens.

    Science.gov (United States)

    Luxembourg, Alain; Hannaman, Drew; Wills, Ken; Bernard, Robert; Tennant, Bud C; Menne, Stephan; Cote, Paul J

    2008-07-29

    The licensed vaccine against hepatitis B virus (HBV) is an effective means to prevent infection, but is not an effective therapeutic strategy to treat established chronic infections when used alone. In an animal model of chronic HBV infection (the woodchuck experimentally infected with woodchuck hepatitis virus (WHV)), the combination of conventional vaccine and potent antiviral drugs has shown promise as a potential therapeutic intervention. This approach might be improved further through the application of newer vaccine technologies. In the present study, we evaluated electroporation (EP)-based intramuscular (i.m.) delivery of a codon-optimized DNA vaccine for the WHV surface antigen (WHsAg) in mice and rabbits. In mice, this immunization procedure compared favorably to vaccination by i.m. injection of the DNA vaccine or i.m. administration of a recombinant WHsAg-alum vaccine, exhibiting characteristics expected to be beneficial for a therapeutic vaccine strategy. These included dose efficiency, consistency, vigorous induction of antibody responses to WHsAg, as well as a Th1 bias. Following scale-up to rabbits, a species that approximates the size of the woodchuck, the EP dosing regimen was markedly more effective than conventional i.m. injection of the DNA vaccine. Taken together, these results provide the foundation for studies of EP-based DNA immunization in the woodchuck in order to further assess its potential as an immunotherapeutic approach for treatment of chronic HBV infection in humans. PMID:18556096

  11. Discovery of Novel Plasmodium falciparum Pre-Erythrocytic Antigens for Vaccine Development.

    Directory of Open Access Journals (Sweden)

    Joao C Aguiar

    Full Text Available Nearly 100% protection against malaria infection can be achieved in humans by immunization with P. falciparum radiation-attenuated sporozoites (RAS. Although it is thought that protection is mediated by T cell and antibody responses, only a few of the many pre-erythrocytic (sporozoite and liver stage antigens that are targeted by these responses have been identified.Twenty seven P. falciparum pre-erythrocytic antigens were selected using bioinformatics analysis and expression databases and were expressed in a wheat germ cell-free protein expression system. Recombinant proteins were recognized by plasma from RAS-immunized subjects, and 21 induced detectable antibody responses in mice and rabbit and sera from these immunized animals were used to characterize these antigens. All 21 proteins localized to the sporozoite: five localized to the surface, seven localized to the micronemes, cytoplasm, endoplasmic reticulum or nucleus, two localized to the surface and cytoplasm, and seven remain undetermined. PBMC from RAS-immunized volunteers elicited positive ex vivo or cultured ELISpot responses against peptides from 20 of the 21 antigens.These T cell and antibody responses support our approach of using reagents from RAS-immunized subjects to screen potential vaccine antigens, and have led to the identification of a panel of novel P. falciparum antigens. These results provide evidence to further evaluate these antigens as vaccine candidates.ClinicalTrials.gov NCT00870987 ClinicalTrials.gov NCT00392015.

  12. Discovery of Novel Plasmodium falciparum Pre-Erythrocytic Antigens for Vaccine Development

    Science.gov (United States)

    Aguiar, Joao C.; Bolton, Jessica; Wanga, Joyce; Sacci, John B.; Iriko, Hideyuki; Mazeika, Julie K.; Han, Eun-Taek; Limbach, Keith; Patterson, Noelle B.; Sedegah, Martha; Cruz, Ann-Marie; Tsuboi, Takafumi; Hoffman, Stephen L.; Carucci, Daniel; Hollingdale, Michael R.; Villasante, Eileen D.; Richie, Thomas L.

    2015-01-01

    Background Nearly 100% protection against malaria infection can be achieved in humans by immunization with P. falciparum radiation-attenuated sporozoites (RAS). Although it is thought that protection is mediated by T cell and antibody responses, only a few of the many pre-erythrocytic (sporozoite and liver stage) antigens that are targeted by these responses have been identified. Methodology Twenty seven P. falciparum pre-erythrocytic antigens were selected using bioinformatics analysis and expression databases and were expressed in a wheat germ cell-free protein expression system. Recombinant proteins were recognized by plasma from RAS-immunized subjects, and 21 induced detectable antibody responses in mice and rabbit and sera from these immunized animals were used to characterize these antigens. All 21 proteins localized to the sporozoite: five localized to the surface, seven localized to the micronemes, cytoplasm, endoplasmic reticulum or nucleus, two localized to the surface and cytoplasm, and seven remain undetermined. PBMC from RAS-immunized volunteers elicited positive ex vivo or cultured ELISpot responses against peptides from 20 of the 21 antigens. Conclusions These T cell and antibody responses support our approach of using reagents from RAS-immunized subjects to screen potential vaccine antigens, and have led to the identification of a panel of novel P. falciparum antigens. These results provide evidence to further evaluate these antigens as vaccine candidates. Trial Registration ClinicalTrials.gov NCT00870987 ClinicalTrials.gov NCT00392015 PMID:26292257

  13. Impaired Antigen-Specific Immune Response to Vaccines in Children with Antibody Production Defects.

    Science.gov (United States)

    Szczawinska-Poplonyk, Aleksandra; Breborowicz, Anna; Samara, Husam; Ossowska, Lidia; Dworacki, Grzegorz

    2015-08-01

    The impaired synthesis of antigen-specific antibodies, which is indispensable for an adaptive immune response to infections, is a fundamental pathomechanism that leads to clinical manifestations in children with antibody production defects. The aim of this study was to evaluate the synthesis of antigen-specific antibodies following immunization in relation to peripheral blood B cell subsets in young children with hypogammaglobulinemia. Twenty-two children, aged from 8 to 61 months, with a deficiency in one or more major immunoglobulin classes participated in the study. Postvaccination antibodies against tetanus and diphtheria toxoids, the surface antigen of the hepatitis B virus, and the capsular Haemophilus influenzae type b polysaccharide antigen were assessed along with an immunophenotypic evaluation of peripheral blood B lymph cell maturation. A deficiency of antibodies against the tetanus toxoid was assessed in 73% of cases and that against the diphtheria toxoid was assessed in 68% of cases, whereas a deficiency of antibodies against the surface antigen of the hepatitis B virus was revealed in 59% of the children included in the study. A defective response to immunization with a conjugate vaccine with the Haemophilus influenzae type b polysaccharide antigen was demonstrated in 55% of hypogammaglobulinemic patients. Increased proportions of transitional B lymph cells and an accumulation of plasmablasts accompanied antibody deficiencies. The defective response to vaccine protein and polysaccharide antigens is a predominating disorder of humoral immunity in children with hypogammaglobulinemia and may result from a dysfunctional state of the cellular elements of the immune system. PMID:26018535

  14. Proteomics-driven Antigen Discovery for Development of Vaccines Against Gonorrhea.

    Science.gov (United States)

    Zielke, Ryszard A; Wierzbicki, Igor H; Baarda, Benjamin I; Gafken, Philip R; Soge, Olusegun O; Holmes, King K; Jerse, Ann E; Unemo, Magnus; Sikora, Aleksandra E

    2016-07-01

    Expanding efforts to develop preventive gonorrhea vaccines is critical because of the dire possibility of untreatable gonococcal infections. Reverse vaccinology, which includes genome and proteome mining, has proven very successful in the discovery of vaccine candidates against many pathogenic bacteria. However, progress with this approach for a gonorrhea vaccine remains in its infancy. Accordingly, we applied a comprehensive proteomic platform-isobaric tagging for absolute quantification coupled with two-dimensional liquid chromatography and mass spectrometry-to identify potential gonococcal vaccine antigens. Our previous analyses focused on cell envelopes and naturally released membrane vesicles derived from four different Neisseria gonorrhoeae strains. Here, we extended these studies to identify cell envelope proteins of N. gonorrhoeae that are ubiquitously expressed and specifically induced by physiologically relevant environmental stimuli: oxygen availability, iron deprivation, and the presence of human serum. Together, these studies enabled the identification of numerous potential gonorrhea vaccine targets. Initial characterization of five novel vaccine candidate antigens that were ubiquitously expressed under these different growth conditions demonstrated that homologs of BamA (NGO1801), LptD (NGO1715), and TamA (NGO1956), and two uncharacterized proteins, NGO2054 and NGO2139, were surface exposed, secreted via naturally released membrane vesicles, and elicited bactericidal antibodies that cross-reacted with a panel of temporally and geographically diverse isolates. In addition, analysis of polymorphisms at the nucleotide and amino acid levels showed that these vaccine candidates are highly conserved among N. gonorrhoeae strains. Finally, depletion of BamA caused a loss of N. gonorrhoeae viability, suggesting it may be an essential target. Together, our data strongly support the use of proteomics-driven discovery of potential vaccine targets as a sound

  15. Comparison of BCG, MPL and cationic liposome adjuvant systems in leishmanial antigen vaccine formulations against murine visceral leishmaniasis

    Directory of Open Access Journals (Sweden)

    Bhowmick Sudipta

    2010-06-01

    Full Text Available Abstract Background The development of an effective vaccine against visceral leishmaniasis (VL caused by Leishmania donovani is an essential aim for controlling the disease. Use of the right adjuvant is of fundamental importance in vaccine formulations for generation of effective cell-mediated immune response. Earlier we reported the protective efficacy of cationic liposome-associated L. donovani promastigote antigens (LAg against experimental VL. The aim of the present study was to compare the effectiveness of two very promising adjuvants, Bacille Calmette-Guerin (BCG and Monophosphoryl lipid A (MPL plus trehalose dicorynomycolate (TDM with cationic liposomes, in combination with LAg, to confer protection against murine VL. Results All the three formulations afforded significant protection against L. donovani in both the visceral organs, liver and spleen. Although comparable level of protection was observed in BCG+LAg and MPL-TDM+LAg immunized mice, highest level of protection was exhibited by the liposomal LAg immunized group. Significant increase in anti-LAg IgG levels were detected in both MPL-TDM+LAg and liposomal LAg immunized animals with higher levels of IgG2a than IgG1. But BCG+LAg failed to induce any antibody response. As an index of cell-mediated immunity DTH responses were measured and significant response was observed in mice vaccinated with all the three different formulations. However, highest responses were observed with liposomal vaccine immunization. Comparative evaluation of IFN-γ and IL-4 responses in immunized mice revealed that MPL-TDM+LAg group produced the highest level of IFN-γ but lowest IL-4 level, while BCG+LAg demonstrated generation of suboptimum levels of both IFN-γ and IL-4 response. Elicitation of moderate levels of prechallenge IFN-γ along with optimum IL-4 corresponds with successful vaccination with liposomal LAg. Conclusion This comparative study reveals greater effectiveness of the liposomal vaccine for

  16. Performance of two Bm86 antigen vaccin formulation against tick using crossbreed bovines in stall test.

    Science.gov (United States)

    Andreotti, Renato

    2006-01-01

    Cattle tick control remains a serious problem for cattle farms in Brazil due to the limited success achieved with chemicals. In Brazil, the use of vaccines for tick control associated with the use of chemicals and pasture rotation may open possibilities for integrated control. However, it is important to know whether regional Boophilus microplus strains are sensitive to antibodies produced by the available antigens: antigen preparations Gavac™ and TickGard(PLUS). The aim of this research was to evaluate the performance of two Bm86 antigen vaccine formulation against tick using crossbred bovines in stall test antigen against a regional B. microplus strain. The experiment was carried out in central Brazil (20 degrees 27'S, 54 degrees 37'W). A trial was conducted in stall conditions on crossbred cattle under controlled infestation. Two groups of 16 animals each, homogeneous in weight and sex, were vaccinated with Gavac™ or TickGard(PLUS), two groups of eight animals as control. Challenge was performed on three alternate days, with 5,000 larvae each time, beginning 21 days after the second injection. The antibody response was measured by ELISA and vaccinated animals presented immune response considering IgG levels. The results showed 49.2% and 46.4% protection efficacy for Gavac™ and TickGard(PLUS), respectively. PMID:16978472

  17. Human Leukocyte Antigens Influence the Antibody Response to Hepatitis B Vaccine.

    Science.gov (United States)

    Jafarzadeh, Abdollah; Bagheri-Jamebozorgi, Masoome; Nemati, Maryam; Golsaz-Shirazi, Forough; Shokri, Fazel

    2015-06-01

    Hepatitis B virus (HBV) infection and its sequelae such as cirrhosis and hepatocellular carcinoma has remained a serious public health problem throughout the world. The WHO strategy for effective control of HBV infection and its complications is mass vaccination of neonates and children within the framework of Expanded Programme on Immunization (EPI). Vaccination with hepatitis B surface antigen (HBsAg) induces protective antibody response (anti-HBs ≥ 10 IU/L) in 90-99% of vaccinees. The lack of response to HBsAg has been attributed to a variety of immunological mechanisms, including defect in antigen presentation, defect in HBsAg-specific T and/or B cell repertoires, T-cell suppression, increase in the regulatory T cell count, lack of necessary help of T-cells for production of anti-HBs by B cells, defect in Th1 and/or Th2 cytokine production and selective killing of HBsAg-specific B-cells by human leukocyte antigen (HLA)-restricted cytotoxic T lymphocytes. The HLA complex plays an important role in many of these immunological processes. A variety of HLA class I, II, and III alleles and antigens have been reported to be associated with antibody response to HBsAg vaccination in different ethnic populations. Moreover, some HLA haplotypes were also associated with responsiveness to HBsAg. In this review the association of the HLA specificities with antibody response to hepatitis B (HB) vaccine is discussed. PMID:26546891

  18. Experimental studies of a vaccine formulation of recombinant human VEGF antigen with aluminum phosphate

    Science.gov (United States)

    Pérez Sánchez, Lincidio; Morera Díaz, Yanelys; Bequet-Romero, Mónica; Ramses Hernández, Gerardo; Rodríguez, Yadira; Castro Velazco, Jorge; Puente Pérez, Pedro; Ayala Avila, Marta; Gavilondo, Jorge V

    2015-01-01

    CIGB-247 is a cancer vaccine that is a formulation of a recombinant protein antigen representative of the human vascular endothelial growth factor (VEGF) with a bacterially-derived adjuvant (VSSP). The vaccine has shown an excellent safety profile in mice, rats, rabbits, not-human primates and in recent clinical trials in cancer patients. Response to the vaccine is characterized by specific antibody titers that neutralize VEGF/VEGFR2 binding and a cytotoxic tumor-specific response. To expand our present anti-VEGF active immunotherapy strategies, we have now studied in mice and non-human primates the effects of vaccination with a formulation of our recombinant VEGF antigen and aluminum phosphate adjuvant (hereafter denominated CIGB-247-A). Administered bi-weekly, CIGB-247-A produces high titers of anti-VEGF IgG blocking antibodies in 2 mice strains. Particularly in BALB/c, the treatment impaired subcutaneous F3II mammary tumor growth and reduced the number of spontaneous lung macro metastases, increasing animals' survival. Spleen cells from specifically immunized mice directly killed F3II tumor cells in vitro. CIGB-247-A also showed to be immunogenic in non-human primates, which developed anti-VEGF blocking antibodies and the ability for specific direct cell cytotoxic responses, all without impairing the healing of deep skin wounds or other side effect. Our results support consideration of aluminum phosphate as a suitable adjuvant for the development of new vaccine formulations using VEGF as antigen. PMID:25891359

  19. Vaccination with Replication Deficient Adenovectors Encoding YF-17D Antigens Induces Long-Lasting Protection from Severe Yellow Fever Virus Infection in Mice.

    Science.gov (United States)

    Bassi, Maria R; Larsen, Mads A B; Kongsgaard, Michael; Rasmussen, Michael; Buus, Søren; Stryhn, Anette; Thomsen, Allan R; Christensen, Jan P

    2016-02-01

    The live attenuated yellow fever vaccine (YF-17D) has been successfully used for more than 70 years. It is generally considered a safe vaccine, however, recent reports of serious adverse events following vaccination have raised concerns and led to suggestions that even safer YF vaccines should be developed. Replication deficient adenoviruses (Ad) have been widely evaluated as recombinant vectors, particularly in the context of prophylactic vaccination against viral infections in which induction of CD8+ T-cell mediated immunity is crucial, but potent antibody responses may also be elicited using these vectors. In this study, we present two adenobased vectors targeting non-structural and structural YF antigens and characterize their immunological properties. We report that a single immunization with an Ad-vector encoding the non-structural protein 3 from YF-17D could elicit a strong CD8+ T-cell response, which afforded a high degree of protection from subsequent intracranial challenge of vaccinated mice. However, full protection was only observed using a vector encoding the structural proteins from YF-17D. This vector elicited virus-specific CD8+ T cells as well as neutralizing antibodies, and both components were shown to be important for protection thus mimicking the situation recently uncovered in YF-17D vaccinated mice. Considering that Ad-vectors are very safe, easy to produce and highly immunogenic in humans, our data indicate that a replication deficient adenovector-based YF vaccine may represent a safe and efficient alternative to the classical live attenuated YF vaccine and should be further tested. PMID:26886513

  20. Successful vaccination against Boophilus microplus and Babesia bovis using recombinat antigens

    Directory of Open Access Journals (Sweden)

    P. Willadsen

    1992-01-01

    Full Text Available Current methods for the control of the cattle tick Boophils microplus and the agent of bovine babesiosis, Babesia bovis are unsatisfactory. Effective immunological control of both parasites would have great advantages. However, naturally acquired immunity to the tick is generally unable to prevent serious production losses. A vaccine against the tick, based on a novel form of immunization, is being developed. A protective antigen has been isolated from the tick, characterized and produced as an effective, recombinant protein. A vaccine incorporating this antigen is currently undergoing field trials. In the Australian situation, improved tick control will probably increase endemic instability with respect to B. bovis. Fortunately, a trivalent, recombinant B. bovis vaccine has also been developed. This too is now undergoing pre-registration field trials.

  1. Long term hepatitis B vaccine in infants born to hepatitis B e antigen positive mothers

    OpenAIRE

    Poovorawan, Y.; Sanpavat, S.; Chumdermpadetsuk, S.; Safary, A.

    1997-01-01

    Neonates of hepatitis B surface antigen (HBsAg) positive and hepatitis B encoded antigen (HBeAg) positive mothers received 10 µg of recombinant hepatitis B vaccine at months 0, 1, 6, or 0, 1, 2, 12, with or without immunoglobulin at birth, and were followed up to the age of 8 years for HBsAg, anti-HBc, and anti-HBs. Some were boosted at month 60. The overall vaccine protection at month 12 was 96.2%. No child became a chronic carrier beyond the age of 3 years, showing that this vaccine provide...

  2. Development of Yersinia pestis F1 antigen-loaded microspheres vaccine against plague

    Directory of Open Access Journals (Sweden)

    Huang SS

    2014-02-01

    Full Text Available Shih-shiung Huang,1 I-Hsun Li,2,3 Po-da Hong,1 Ming-kung Yeh1,2,41Biomedical Engineering Program, Graduate Institute of Engineering, Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, Republic of China; 2School of Pharmacy, 3Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China; 4Food and Drug Administration, Ministry of Health and Welfare, Taipei, Taiwan, Republic of ChinaAbstract: Yersinia pestis F1 antigen-loaded poly(DL-lactide-co-glycolide/polyethylene glycol (PEG (PLGA/PEG microspheres were produced using a water-in-oil-in-water emulsion/solvent extraction technique and assayed for their percent yield, entrapment efficiency, surface morphology, particle size, zeta potential, in vitro release properties, and in vivo animal protect efficacy. The Y. pestis F1 antigen-loaded microspheres (mean particle size 3.8 µm exhibited a high loading capacity (4.5% w/w, yield (85.2%, and entrapment efficiency (38.1%, and presented a controlled in vitro release profile with a low initial burst (18.5%, then continued to release Y. pestis F1 antigen over 70 days. The distribution (% of Y. pestis F1 on the microspheres surface, outer layer, and core was 3.1%, 28.9%, and 60.7%, respectively. A steady release rate was noticed to be 0.55 µg Y. pestis F1 antigen/mg microspheres/day of Y. pestis F1 antigen release maintained for 42 days. The cumulative release amount at the 1st, 28th, and 42nd days was 8.2, 26.7, and 31.0 µg Y. pestis F1 antigen/mg microspheres, respectively. The 100 times median lethal dose 50% (LD50 of Y. pestis Yokohama-R strain by intraperitoneal injection challenge in mice test, in which mice received one dose of 40 µg F1 antigen content of PLGA/PEG microspheres, F1 antigen in Al(OH3, and in comparison with F1 antigen in Al(OH3 vaccine in two doses, was evaluated after given by subcutaneous

  3. Novel Plasmodium falciparum malaria vaccines: evidence-based searching for variant surface antigens as candidates for vaccination against pregnancy-associated malaria

    DEFF Research Database (Denmark)

    Staalsoe, Trine; Jensen, Anja T R; Theander, Thor G; Hviid, Lars

    2002-01-01

    statistically significant co-variation with protection rather than on demonstration of causal relationships. We have studied the relationship between variant surface antigen-specific antibodies and clinical protection from Plasmodium falciparum malaria in general, and from pregnancy-associated malaria (PAM) in......Malaria vaccine development has traditionally concentrated on careful molecular, biochemical, and immunological characterisation of candidate antigens. In contrast, evidence of the importance of identified antigens in immunity to human infection and disease has generally been limited to...... particular, to provide robust evidence of a causal link between the two in order to allow efficient and evidence-based identification of candidate antigens for malaria vaccine development....

  4. Plant-Based Vaccine: Mice Immunized with Chloroplast-Derived Anthrax Protective Antigen Survive Anthrax Lethal Toxin Challenge

    OpenAIRE

    Koya, Vijay; Moayeri, Mahtab; Leppla, Stephen H.; Daniell, Henry

    2005-01-01

    The currently available human vaccine for anthrax, derived from the culture supernatant of Bacillus anthracis, contains the protective antigen (PA) and traces of the lethal and edema factors, which may contribute to adverse side effects associated with this vaccine. Therefore, an effective expression system that can provide a clean, safe, and efficacious vaccine is required. In an effort to produce anthrax vaccine in large quantities and free of extraneous bacterial contaminants, PA was expre...

  5. A vaccine prepared from the 22 nm particles of surface hepatitis B antigen (HBsAg)

    International Nuclear Information System (INIS)

    A method for obtaining a subunit inactivated vaccine preparation from the 22-nm particles of HBsAg is proposed. For inactivation of the residual infectious hepatitis B virus (HBV) the preparations were successively treated with 1% sodium dodecyl sulfate (SDS) and nucleases. In addition, thermal denaturation and ultraviolet irradiation of HBV DNA were used. As a control the biologic activity of a reference virus (SV40) was tested after the same treatment. The effectiveness of DNA inactivation was monitored by adding 3H-thymidine labeled reference virus to the vaccine preparations. The purified and inactivated HBsAg was adsorbed on Al2O3. Antigenicity was calculated on the basis of the determination of antibody in guinea pigs immunized with various doses of the vaccine, and the release of 125I- HBsAg from blood and kidneys in immunized and control mice was analyzed. Possible methods of inactivation and control of HBV vaccine is discussed

  6. Co-expression of tumor antigen and interleukin-2 from an adenoviral vector augments the efficiency of therapeutic tumor vaccination

    DEFF Research Database (Denmark)

    Jensen, Benjamin Anderschou Holbech; Steffensen, Maria Abildgaard; Nørgaard Nielsen, Karen;

    2014-01-01

    approach where the target antigen fused to Ii is expressed from the adenoviral E1 region and IL-2 is expressed from the E3 region. Immunization of mice with this new vector construct resulted in an augmented primary effector CD8+ T-cell response. Furthermore, in a melanoma model we observed significantly...... prolonged tumor control in vaccinated wild type (WT) mice. The improved tumor control required antigen-specific cells, since no tumor control was observed, unless the melanoma cells expressed the vaccine targeted antigen. We also tested our new vaccine in immunodeficient (CD80/86 deficient) mice. Following...

  7. Development and evaluation of two subunit vaccine candidates containing antigens of hepatitis E virus, rotavirus, and astrovirus.

    Science.gov (United States)

    Xia, Ming; Wei, Chao; Wang, Leyi; Cao, Dianjun; Meng, Xiang-Jin; Jiang, Xi; Tan, Ming

    2016-01-01

    Hepatitis E virus (HEV), rotavirus (RV), and astrovirus (AstV) are important pathogens that transmit through a common fecal-oral route, causing hepatitis (HEV) and gastroenteritis (RV and AstV) respectively in humans. In this study, we developed and evaluated two subunit vaccine candidates that consisted of the same protruding or spike protein antigens of the three viruses in two formats, a fusion of the three antigens into one molecule (fused vaccine) vs. a mixture of the three free antigens together (mixed vaccine). Both vaccines were easily made via E. coli expression system. Mouse immunization experiments showed that the fused vaccine elicited significantly higher antibody responses against the three viral antigens than those induced by the mixed vaccine. In addition, the mouse post-immune antisera of the fused vaccine revealed significantly higher neutralizing titers against HEV infection in cell culture, as well as significantly higher 50% blocking titers (BT50) against RV VP8-HBGA receptor interactions than those of the post-immune antisera after immunization of the mixed vaccine. Thus, the fused vaccine is a promising trivalent vaccine candidate against HEV, RV, and AstV, which is worth for further development. PMID:27194006

  8. Development and evaluation of two subunit vaccine candidates containing antigens of hepatitis E virus, rotavirus, and astrovirus

    Science.gov (United States)

    Xia, Ming; Wei, Chao; Wang, Leyi; Cao, Dianjun; Meng, Xiang-Jin; Jiang, Xi; Tan, Ming

    2016-01-01

    Hepatitis E virus (HEV), rotavirus (RV), and astrovirus (AstV) are important pathogens that transmit through a common fecal-oral route, causing hepatitis (HEV) and gastroenteritis (RV and AstV) respectively in humans. In this study, we developed and evaluated two subunit vaccine candidates that consisted of the same protruding or spike protein antigens of the three viruses in two formats, a fusion of the three antigens into one molecule (fused vaccine) vs. a mixture of the three free antigens together (mixed vaccine). Both vaccines were easily made via E. coli expression system. Mouse immunization experiments showed that the fused vaccine elicited significantly higher antibody responses against the three viral antigens than those induced by the mixed vaccine. In addition, the mouse post-immune antisera of the fused vaccine revealed significantly higher neutralizing titers against HEV infection in cell culture, as well as significantly higher 50% blocking titers (BT50) against RV VP8-HBGA receptor interactions than those of the post-immune antisera after immunization of the mixed vaccine. Thus, the fused vaccine is a promising trivalent vaccine candidate against HEV, RV, and AstV, which is worth for further development. PMID:27194006

  9. Incomplete effector/memory differentiation of antigen-primed CD8+ T cells in gene gun DNA-vaccinated mice

    DEFF Research Database (Denmark)

    Bartholdy, Christina; Stryhn, Anette; Hansen, Nils Jacob Vest;

    2003-01-01

    DNA vaccination is an efficient way to induce CD8+ T cell memory, but it is still unclear to what extent such memory responses afford protection in vivo. To study this, we induced CD8+ memory responses directed towards defined viral epitopes, using DNA vaccines encoding immunodominant MHC class I...

  10. Antigen dose escalation study of a VEGF-based therapeutic cancer vaccine in non human primates.

    Science.gov (United States)

    Morera, Yanelys; Bequet-Romero, Mónica; Ayala, Marta; Pérez, Pedro Puente; Castro, Jorge; Sánchez, Javier; Alba, José Suárez; Ancízar, Julio; Cosme, Karelia; Gavilondo, Jorge V

    2012-01-01

    CIGB-247 is a cancer therapeutic, based on recombinant modified human vascular endothelial growth factor (VEGF) as antigen, in combination with the oil free adjuvant VSSP (very small sized proteoliposomes of Neisseria meningitidis outer membrane). Our previous experimental studies in mice with CIGB-247 have shown that the vaccine has both anti-tumoral and anti-metastatic activity, and produces both antibodies that block VEGF-VEGF receptor interaction, and a specific T-cell cytotoxic response against tumor cells. CIGB-247, with an antigen dose of 100 μg, has been characterized by an excellent safety profile in mice, rats, rabbits, and non human primates. In this article we extend the immunogenicity and safety studies of CIGB-247 in non human primates, scaling the antigen dose from 100 μg to 200 and 400 μg/vaccination. Our results indicate that such dose escalation did not affect animal behavior, clinical status, and blood parameters and biochemistry. Also, vaccination did not interfere with skin deep skin wound healing. Anti-VEGF IgG antibodies and specific T-cell mediated responses were documented at all three studied doses. Antigen dose apparently did not determine differences in maximum antibody titer during the 8 weekly immunization induction phase, or the subsequent increase in antibodies seen for monthly boosters delivered afterwards. Higher antigen doses had a positive influence in antibody titer maintenance, after cessation of immunizations. Boosters were important to achieve maximum antibody VEGF blocking activity, and specific T-cell responses in all individuals. Purified IgG from CIGB-247 immunized monkey sera was able to impair proliferation and formation of capillary-like structures in Matrigel, for HMEC cells in culture. Altogether, these results support the further clinical development of the CIGB-247 therapeutic cancer vaccine, and inform on the potential mechanisms involved in its effect. PMID:22075086

  11. Three-day dendritic cells for vaccine development: Antigen uptake, processing and presentation

    Directory of Open Access Journals (Sweden)

    Schendel Dolores J

    2010-09-01

    Full Text Available Abstract Background Antigen-loaded dendritic cells (DC are capable of priming naïve T cells and therefore represent an attractive adjuvant for vaccine development in anti-tumor immunotherapy. Numerous protocols have been described to date using different maturation cocktails and time periods for the induction of mature DC (mDC in vitro. For clinical application, the use of mDC that can be generated in only three days saves on the costs of cytokines needed for large scale vaccine cell production and provides a method to produce cells within a standard work-week schedule in a GMP facility. Methods In this study, we addressed the properties of antigen uptake, processing and presentation by monocyte-derived DC prepared in three days (3d mDC compared with conventional DC prepared in seven days (7d mDC, which represent the most common form of DC used for vaccines to date. Results Although they showed a reduced capacity for spontaneous antigen uptake, 3d mDC displayed higher capacity for stimulation of T cells after loading with an extended synthetic peptide that requires processing for MHC binding, indicating they were more efficient at antigen processing than 7d DC. We found, however, that 3d DC were less efficient at expressing protein after introduction of in vitro transcribed (ivtRNA by electroporation, based on published procedures. This deficit was overcome by altering electroporation parameters, which led to improved protein expression and capacity for T cell stimulation using low amounts of ivtRNA. Conclusions This new procedure allows 3d mDC to replace 7d mDC for use in DC-based vaccines that utilize long peptides, proteins or ivtRNA as sources of specific antigen.

  12. Cattle tick vaccines: many candidate antigens, but will a commercially viable product emerge?

    Science.gov (United States)

    Guerrero, Felix D; Miller, Robert J; Pérez de León, Adalberto A

    2012-05-01

    The cattle tick, Rhipicephalus microplus, is arguably the world's most economically important external parasite of cattle. Sustainable cattle tick control strategies are required to maximise the productivity of cattle in both large production operations and small family farms. Commercially available synthetic acaricides are commonly used in control and eradication programs, but indiscriminate practices in their application have resulted in the rapid evolution of resistance among populations in tropical and subtropical regions where the invasive R. microplus thrives. The need for novel technologies that could be used alone or in combination with commercially available synthetic acaricides is driving a resurgence of cattle tick vaccine discovery research efforts by various groups globally. The aim is to deliver a next-generation vaccine that has an improved efficacy profile over the existing Bm86-based cattle tick vaccine product. We present a short review of these projects and offer our opinion on what constitutes a good target antigen and vaccine, and what might influence the market success of candidate vaccines. The previous experience with Bm86-based vaccines offers perspective on marketing and producer acceptance aspects that a next-generation cattle tick vaccine product must meet for successful commercialisation. PMID:22549026

  13. Vaccination of pigs with Toxoplasma gondii antigens incorporated in immunostimulating complexes (iscoms)

    OpenAIRE

    Freire R.L.; Navarro I.T.; Bracarense A.P.F.R.L.; Gennari S.M.

    2003-01-01

    Immunity to Toxoplasma gondii was studied in pigs, after vaccination with T. gondii antigens incorporated into immunostimulating complexes. Nine pigs (group 1 - G1) were inoculated subcutaneously with T. gondii iscoms (LIV-5 sample) and three doses were given at 21 and 13 day-intervals. The results were compared in other three groups of nine pigs each: animals in group 2 (G2) were immunized with the LIV-5 antigens without Quil A, animals in group 3 (G3) were inoculated with tachyzoites of RH ...

  14. Vaccine delivery by penetratin: mechanism of antigen presentation by dendritic cells.

    Science.gov (United States)

    Pouniotis, Dodie; Tang, Choon-Kit; Apostolopoulos, Vasso; Pietersz, Geoffrey

    2016-08-01

    Cell-penetrating peptides (CPP) or membrane-translocating peptides such as penetratin from Antennapedia homeodomain or TAT from human immunodeficiency virus are useful vectors for the delivery of protein antigens or their cytotoxic (Tc) or helper (Th) T cell epitopes to antigen-presenting cells. Mice immunized with CPP containing immunogens elicit antigen-specific Tc and/or Th responses and could be protected from tumor challenges. In the present paper, we investigate the mechanism of class I and class II antigen presentation of ovalbumin covalently linked to penetratin (AntpOVA) by bone marrow-derived dendritic cells with the use of biochemical inhibitors of various pathways of antigen processing and presentation. Results from our study suggested that uptake of AntpOVA is via a combination of energy-independent (membrane fusion) and energy-dependent pathways (endocytosis). Once internalized by either mechanism, multiple tap-dependent or independent antigen presentation pathways are accessed while not completely dependent on proteasomal processing but involving proteolytic trimming in the ER and Golgi compartments. Our study provides an understanding on the mechanism of antigen presentation mediated by CPP and leads to greater insights into future development of vaccine formulations. PMID:27138940

  15. Exosome targeting of tumor antigens expressed by cancer vaccines can improve antigen immunogenicity and therapeutic efficacy.

    Science.gov (United States)

    Rountree, Ryan B; Mandl, Stefanie J; Nachtwey, James M; Dalpozzo, Katie; Do, Lisa; Lombardo, John R; Schoonmaker, Peter L; Brinkmann, Kay; Dirmeier, Ulrike; Laus, Reiner; Delcayre, Alain

    2011-08-01

    MVA-BN-PRO (BN ImmunoTherapeutics) is a candidate immunotherapy product for the treatment of prostate cancer. It encodes 2 tumor-associated antigens, prostate-specific antigen (PSA), and prostatic acid phosphatase (PAP), and is derived from the highly attenuated modified vaccinia Ankara (MVA) virus stock known as MVA-BN. Past work has shown that the immunogenicity of antigens can be improved by targeting their localization to exosomes, which are small, 50- to 100-nm diameter vesicles secreted by most cell types. Exosome targeting is achieved by fusing the antigen to the C1C2 domain of the lactadherin protein. To test whether exosome targeting would improve the immunogenicity of PSA and PAP, 2 additional versions of MVA-BN-PRO were produced, targeting either PSA (MVA-BN-PSA-C1C2) or PAP (MVA-BN-PAP-C1C2) to exosomes, while leaving the second transgene untargeted. Treatment of mice with MVA-BN-PAP-C1C2 led to a striking increase in the immune response against PAP. Anti-PAP antibody titers developed more rapidly and reached levels that were 10- to 100-fold higher than those for mice treated with MVA-BN-PRO. Furthermore, treatment with MVA-BN-PAP-C1C2 increased the frequency of PAP-specific T cells 5-fold compared with mice treated with MVA-BN-PRO. These improvements translated into a greater frequency of tumor rejection in a PAP-expressing solid tumor model. Likewise, treatment with MVA-BN-PSA-C1C2 increased the antigenicity of PSA compared with treatment with MVA-BN-PRO and resulted in a trend of improved antitumor efficacy in a PSA-expressing tumor model. These experiments confirm that targeting antigen localization to exosomes is a viable approach for improving the therapeutic potential of MVA-BN-PRO in humans. PMID:21670078

  16. Merozoite Surface Antigen 2 Proteins of Babesia bovis Vaccine Breakthrough Isolates Contain a Unique Hypervariable Region Composed of Degenerate Repeats

    OpenAIRE

    Berens, Shawn J.; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The merozoite surface antigen 2 (MSA-2) proteins of Babesia bovis are members of the variable merozoite surface antigen (VMSA) family that have been implicated in erythrocyte invasion and are important targets for antibody-mediated blocking of invasion. Extensive sequence variation in another VMSA member, MSA-1, has been shown in all vaccine breakthrough isolates. To test the hypothesis that the msa-2 genes of vaccine breakthrough isolates would also encode a diverse set of proteins, the comp...

  17. Protection of Mice with a Divalent Tuberculosis DNA Vaccine Encoding Antigens Ag85B and MPT64

    Institute of Scientific and Technical Information of China (English)

    Xia TIAN; Hong CAI; Yu-Xian ZHU

    2004-01-01

    DNA vaccine may be a promising tool for controlling tuberculosis development. However,vaccines encoding single antigens of mycobacterium did not produce protective effect as BCG did. In the present study, we evaluated the immunogenicity and protective efficacy of a divalent DNA vaccine encoding two immunodominant antigens Ag85B and MPT64 of Mycobacterium tuberculosis. We found that both humoral and Th1-type (high IFN-γ, low IL-4) cellular responses obtained from the divalent DNA vaccine group were significantly higher than that conferred by BCG. RT-PCR results showed that antigens were expressed differentially in various organs in divalent DNA vaccine group. The survival rate for mice treated with the divalent DNA vaccine after challenging with high doses of virulent M. tuberculosis H37Rv was significantly higher than that of the BCG group or any of the single DNA vaccine group. Significant differences were also found between the single and divalent DNA vaccinated mice in terms of body, spleen and lung weight. Bacterial loading decreased about 2000-fold in lungs and about 100-fold in spleens of divalent DNA vaccinated mice when compared with that of the control group. We conclude that our divalent DNA vaccine may be a better choice for controlling tuberculosis disease in animals.

  18. Chloroplast-Derived Vaccine Antigens and Biopharmaceuticals: Expression, Folding, Assembly and Functionality

    OpenAIRE

    Chebolu, S.; Daniell, H

    2009-01-01

    Chloroplast genetic engineering offers several advantages, including high levels of transgene expression, transgene containment via maternal inheritance, and multi-gene expression in a single transformation event. Oral delivery is facilitated by hyperexpression of vaccine antigens against cholera, tetanus, anthrax, plague, or canine parvovirus (4%–31% of total soluble protein, TSP) in transgenic chloroplasts (leaves) or non-green plastids (carrots, tomato) as well as the availability of antib...

  19. Engineering the chloroplast targeted malarial vaccine antigens in Chlamydomonas starch granules.

    Directory of Open Access Journals (Sweden)

    David Dauvillée

    Full Text Available BACKGROUND: Malaria, an Anopheles-borne parasitic disease, remains a major global health problem causing illness and death that disproportionately affects developing countries. Despite the incidence of malaria, which remains one of the most severe infections of human populations, there is no licensed vaccine against this life-threatening disease. In this context, we decided to explore the expression of Plasmodium vaccine antigens fused to the granule bound starch synthase (GBSS, the major protein associated to the starch matrix in all starch-accumulating plants and algae such as Chlamydomonas reinhardtii. METHODS AND FINDINGS: We describe the development of genetically engineered starch granules containing plasmodial vaccine candidate antigens produced in the unicellular green algae Chlamydomonas reinhardtii. We show that the C-terminal domains of proteins from the rodent Plasmodium species, Plasmodium berghei Apical Major Antigen AMA1, or Major Surface Protein MSP1 fused to the algal granule bound starch synthase (GBSS are efficiently expressed and bound to the polysaccharide matrix. Mice were either immunized intraperitoneally with the engineered starch particles and Freund adjuvant, or fed with the engineered particles co-delivered with the mucosal adjuvant, and challenged intraperitoneally with a lethal inoculum of P. Berghei. Both experimental strategies led to a significantly reduced parasitemia with an extension of life span including complete cure for intraperitoneal delivery as assessed by negative blood thin smears. In the case of the starch bound P. falciparum GBSS-MSP1 fusion protein, the immune sera or purified immunoglobulin G of mice immunized with the corresponding starch strongly inhibited in vitro the intra-erythrocytic asexual development of the most human deadly plasmodial species. CONCLUSION: This novel system paves the way for the production of clinically relevant plasmodial antigens as algal starch-based particles

  20. Human Leukocyte Antigens Influence the Antibody Response to Hepatitis B Vaccine

    Directory of Open Access Journals (Sweden)

    Abdollah Jafarzadeh

    2015-10-01

    Full Text Available Hepatitis B virus (HBV infection and its sequelae such as cirrhosis and hepatocellular carcinoma has remained a serious public health problem throughout the world. The WHO strategy for effective control of HBV infection and its complications is mass vaccination of neonates and children within the framework of Expanded Programme on Immunization (EPI. Vaccination with hepatitis B surface antigen (HBsAg induces protective antibody response (anti-HBs ≥ 10 IU/L in 90-99% of vaccinees.The lack of  response to  HBsAg has  been attributed  to a variety of  immunological mechanisms, including defect in antigen presentation, defect in HBsAg-specific T and/or B cell repertoires, T-cell suppression, increase in the regulatory T cell count, lack of necessary help of T-cells for production of anti-HBs by B cells, defect in Th1 and/or Th2 cytokine production  and  selective  killing  of  HBsAg-specific  B-cells  by  human  leukocyte  antigen (HLA-restricted cytotoxic T lymphocytes. The HLA complex plays an important role in many of these immunological processes.A variety of HLA class I, II, and III alleles and antigens have been reported to beassociated with antibody response to HBsAg vaccination in different ethnic populations. Moreover, some HLA haplotypes were also associated with responsiveness to HBsAg.In this review the association of the HLA specificities with antibody response to hepatitis B (HB vaccine is discussed.

  1. Control of Boophilus microplus populations in grazing cattle vaccinated with a recombinant Bm86 antigen preparation.

    Science.gov (United States)

    Rodríguez, M; Penichet, M L; Mouris, A E; Labarta, V; Luaces, L L; Rubiera, R; Cordovés, C; Sánchez, P A; Ramos, E; Soto, A

    1995-04-01

    Current methods for the control of cattle tick Boophilus microplus infestations are not effective and the parasite remains a serious problem for the cattle industry in tropical and subtropical areas. Recently, we developed a vaccine against B. microplus employing a recombinant Bm86 (rBm86) antigen preparation (Gavac, Heber Biotec) and it was shown to induce a protective response in vaccinated animals under controlled conditions. Here we show that, under field conditions in grazing cattle, the vaccine is able to control B. microplus populations. Two parasite-free farms were employed for the study. In the first farm, animals were vaccinated with the recombinant vaccine, while, in the second, animals received a saline injection in adjuvant. After immunization, animals were artificially infected and the infestation rate was recorded. Over the 33 weeks of the experiment, the infestation rate was lower in the vaccinated group compared with the control group. At the end of the experiment it was necessary to use chemicals in the control farm after serious losses in production and animals. PMID:7660571

  2. Vaccination with a cocktail of Ancylostoma ceylanicum recombinant antigens leads to worm burden reduction in hamsters.

    Science.gov (United States)

    Wiśniewski, Marcin; Łapiński, Maciej; Daniłowicz-Luebert, Emilia; Jaros, Sławomir; Długosz, Ewa; Wędrychowicz, Halina

    2016-09-01

    Hookworms, a group to which Ancylostoma ceylanicum belongs, are gastrointestinal nematodes that infect more than 700 million people around the world. They are a leading cause of anemia in developing countries. In order to effectively prevent hookworm infections research is conducted to develop an effective vaccine using recombinant antigens of the parasite. The aim of this study was to examine the influence of the hosts' on protection against ancylostomiasis and the shaping of the humoral immune response among Syrian hamsters after immunization with a cocktail of five A. ceylanicum recombinant antigens. Ace-ASP-3, Ace-ASP-4, Ace-APR-1, Ace-MEP-6 and Ace-MEP-7 were obtained in the pET expression system. Immunization with a vaccine cocktail resulted in a 33.5% worm burden reduction. The immunogenicity of the recombinant proteins were determined using ELISA. Statistical analysis showed that vaccinated hamsters developed stronger humoral responses to four of five recombinant antigens (the exception being Ace-ASP-3) compared to hamsters from the control group. PMID:27447220

  3. TSOL18 Vaccine Antigen of Taenia solium: Development of Monoclonal Antibodies and Field Testing of the Vaccine in Cameroon

    Directory of Open Access Journals (Sweden)

    Assana, E.

    2010-01-01

    Full Text Available Chapter 1 reviews the literature about the immunological aspects of taeniid cestode infections and the existing vaccines against Taenia solium cysticercosis in pigs. One of the most promising vaccines is TSOL18, a protein that has been identified in the oncosphere of Taenia solium and expressed as a recombinant molecule in E. coli. Repeated experimental trials have shown that this vaccine is able to protect up to 100% of the immunised pigs against a challenge infection with T. solium. Antibodies raised by the vaccine are capable of killing the parasite in in vitro cultures and it is believed that antibody and complement mediated killing of invading parasites is the major protective immune mechanism induced by vaccination with TSOL18. The identification of the villages with a high risk of T. solium infection, which could subsequently be used in the vaccine trial, is reported in chapter 2. A survey was conducted in 150 households owning 1756 pigs in the rural areas of Mayo-Danay division in the far north region of Cameroon. A questionnaire survey was carried out to collect information on the pig farming system and to identify potential risk factors for T. solium cysticercosis infection in pigs. Blood samples were collected from 398 pigs with the aim of estimating the sero-prevalence of Taenia solium cysticercosis. The results showed that 90.7% of the pigs were free roaming during the dry season and that 42.7% of households keeping pigs in the rural areas had no latrine facility. Seventy six percent of the interviewed pig owners affirmed that the members of the household used open field defecation. ELISA for antigen and antibody detection showed an apparent prevalence of porcine cysticercosis of 24.6% and 32.2%, respectively. A Bayesian approach using the conditional dependence between the two diagnostic tests indicated that the true sero-prevalence of cysticercosis in Mayo-Danay was 26.6%. Binary logistic regression analysis indicated that the

  4. Global inhibition of DC priming capacity in the spleen of self-antigen vaccinated mice requires IL-10

    Directory of Open Access Journals (Sweden)

    Douglas Matthew Marvel

    2014-02-01

    Full Text Available DC in the spleen are highly activated following intravenous vaccination with a foreign antigen, promoting expansion of effector T cells, but remain phenotypically and functionally immature after vaccination with a self-antigen. Up-regulation or suppression of expression of a cohort of pancreatic enzymes 24-72 hours post-vaccination can be used as a biomarker of stimulatory versus toleragenic DC, respectively. Here we show, using MUC1 transgenic mice (MUC1.Tg and a vaccine based on the MUC1 peptide which these mice perceive as a self-antigen, that the difference in enzyme expression that predicts whether DC will promote immune response or immune tolerance, is seen as early as 4-8 hours following vaccination. We also identify early production of IL-10 as a predominant factor that both correlates with this early time point and controls DC function. Pre-treating mice with an antibody against the IL-10 receptor (IL-10R prior to vaccination results in DC that up-regulate CD40, CD80, and CD86 and promote stronger IFNγ+ T cell responses. This study suggests that transient inhibition of IL-10 prior to vaccination could improve responses to cancer vaccines that utilize self-tumor antigens.

  5. Enhancement of DNA vaccine potency through linkage of antigen to filamentous bacteriophage coat protein III domain I

    DEFF Research Database (Denmark)

    Cuesta, Àngel M; Suárez, Eduardo; Larsen, Martin; Jensen, Kim Bak; Sanz, Laura; Compte, Marta; Kristensen, Peter; Álvarez-Vallina, Luis

    2006-01-01

    Although DNA-based cancer vaccines have been successfully tested in mouse models, a major drawback of cancer vaccination still remains, namely that tumour antigens are weak and fail to generate a vigorous immune response in tumour-bearing patients. Genetic technology offers strategies for promoti...

  6. Identifying protective Streptococcus pyogenes vaccine antigens recognized by both B and T cells in human adults and children

    DEFF Research Database (Denmark)

    Mortensen, Rasmus; Nissen, Thomas Nørrelykke; Fredslund, Sine;

    2016-01-01

    No commercial vaccine exists against Group A streptococci (GAS; Streptococcus pyogenes) and only little is known about anti-GAS protective immunity. In our effort to discover new protective vaccine candidates, we selected 21 antigens based on an in silico evaluation. These were all well...

  7. Vaccination of pigs with Toxoplasma gondii antigens incorporated in immunostimulating complexes (iscoms

    Directory of Open Access Journals (Sweden)

    Freire R.L.

    2003-01-01

    Full Text Available Immunity to Toxoplasma gondii was studied in pigs, after vaccination with T. gondii antigens incorporated into immunostimulating complexes. Nine pigs (group 1 - G1 were inoculated subcutaneously with T. gondii iscoms (LIV-5 sample and three doses were given at 21 and 13 day-intervals. The results were compared in other three groups of nine pigs each: animals in group 2 (G2 were immunized with the LIV-5 antigens without Quil A, animals in group 3 (G3 were inoculated with tachyzoites of RH T. gondii isolate, and animals in group 4 (G4 received no vaccination. Four animals were neither vaccinated nor challenged with T. gondii (group 5 - G5. Thirty days after vaccination, pigs were challenged orally with 5´10(4 oocysts at AS-28 T. gondii isolate. Euthanasia was carried out 47 days after challenge and specimens of the heart, muscle, brain, liver, tongue and retina were inoculated into mice. Three out of nine pigs from G2 and one out of nine pigs from G4 showed hypertermia after the challenge. Antibody response was analysed by indirect fluorescent antibody test. The first iscom immunization (G1 induced low antibody levels, the second and third produced high antibody levels, similarly to the RH isolate infection (G3. Western blotting analysis indicated that the antibody response in animals in G1, after challenge, was more intense than in animals in the non-vaccinated group. T. gondii was not isolated by bioassays from tissues of iscom vaccinated pigs, while recovery was obtained from four animals in G4, one in G2 and one in G3.

  8. Evaluation of antigens stability of tobacco seeds as edible vaccine against VTEC strains

    Directory of Open Access Journals (Sweden)

    Luciana Rossi

    2015-11-01

    Full Text Available Plants have represent a promising alternative for biopharmaceutical proteins (Ma et al., 2003; Rossi et al., 2014. Many plant based edible vaccines have been shown to be effective in inducing local immune responses (Rossi et al., 2013. Edible vaccines can activate both mucosal and systemic immunity, as they come in contact with the digestive tract lining. This dual effect would provide first-line defense against pathogens invading through the mucosa. The antigens are released in the intestines are taken up by M cells that are present over the Payer’s patches (in the ileum and the gut associated lymphoid tissue (GALT. Edible vaccines represent an important worldwide goal for the prevention of the enteric diseases, also in livestock. In particular, the enteric infections are a significant clinical problem in pigs. Verocytotoxic Escherichia (E. coli strains are responsible for serious enterotoxaemia that causes important economic losses in the pig industry. The production of a vaccine for oral administration of transgenic seeds could be a practical and efficient system to prevent the infection and to reduce the antibiotic use. This study was focused on tobacco plants, previously transformed by agroinfection for the seed-specific expression of antigenic proteins (F18 adhesive fimbriae and the B subunit of the Vt2e toxin as model of edible vaccines against verocytotoxic E. coli strains. The dietary administration of transgenic tobacco seeds promotes a significant increase in the number of mucosal IgA-producing cells of the tunica propria in both small and large intestine in mice (Rossi et al., 2013. A protective effect of oral administration of transgenic tobacco seeds was also observed against verocytotoxic Escherichia coli infection in piglets (Rossi et al., 2014. The aim of this study was to assess the seed-expression stability, that is a important requirement in the vaccine production, of F 18 and Vt2e-B heterologous genes into the progeny of

  9. Early cellular immune response to a new candidate mycobacterial vaccine antigen in childhood tuberculosis.

    Science.gov (United States)

    Schepers, K; Dirix, V; Mouchet, F; Verscheure, V; Lecher, S; Locht, C; Mascart, F

    2015-02-18

    The search for novel vaccines against tuberculosis (TB) would benefit from in-depths knowledge of the human immune responses to Mycobacterium tuberculosis (Mtb) infection. Here, we characterised in a low TB incidence country, the immune responses to a new candidate vaccine antigen against TB, the heparin-binding haemagglutinin (HBHA), in young children in contact with an active TB case (aTB). Children with no history of BCG vaccination were compared to those vaccinated at birth to compare the initial immune responses to HBHA with secondary immune responses. Fifty-eight children with aTB and 76 with latent TB infection (LTBI) were included and they were compared to 90 non-infected children. Whereas Mtb-infected children globally secreted more interferon-gamma (IFN-γ) in response to HBHA compared to the non-infected children, these IFN-γ concentrations were higher in previously BCG-vaccinated compared to non-vaccinated children. The IFN-γ concentrations were similar in LTBI and aTB children, but appeared to differ qualitatively. Whereas the IFN-γ secretion induced by native methylated and recombinant non-methylated HBHA were well correlated for aTB, this was not the case for LTBI children. Thus, Mtb-infected young children develop IFN-γ responses to HBHA that are enhanced by prior BCG vaccination, indicating BCG-induced priming, thereby supporting a prime-boost strategy for HBHA-based vaccines. The qualitative differences between aTB and LTBI in their HBHA-induced IFN-γ responses may perhaps be exploited for diagnostic purposes. PMID:25583385

  10. Intranasal vaccination with adjuvant-free S. aureus antigens effectively protects mice against experimental sepsis.

    Science.gov (United States)

    Stegmiller, Nataly Pescinalli; Barcelos, Estevão Carlos; Leal, Janine Miranda; Covre, Luciana Polaco; Donatele, Dirlei Molinari; de Matos Guedes, Herbet Leonel; Cunegundes, Marco Cesar; Rodrigues, Rodrigo Ribeiro; Gomes, Daniel Cláudio Oliviera

    2016-06-24

    Staphylococcus aureus (S. aureus) is a Gram-positive coccal bacterium comprising part of the human skin, nares and gastrointestinal tract normal microbiota. It is also an important cause of nosocomial/community-acquired infections in humans and animals, which can cause a diverse array of infections, including sepsis, which is a progressive systemic inflammation response syndrome that is frequently fatal. The emergence of drug-resistant strains and the high toxicity of the treatments used for these infections point out the need to develop an effective, inexpensive and safe vaccine that can be used prophylactically. In this work, we used an experimental sepsis model to evaluate the effectiveness of whole antigens from S. aureus (SaAg) given by the intranasal route to induce protective immunity against S. aureus infection in mice. BALB/c mice were vaccinated via intranasal or intramuscular route with two doses of SaAg, followed by biocompatibility and immunogenicity evaluations. Vaccinated animals did not show any adverse effects associated with the vaccine, as determined by transaminase and creatinine measurements. Intranasal, but not intramuscular vaccination with SaAg led to a significant reduction in IL-10 production and was associated with increased level of IFN-γ and NO. SaAg intranasal vaccination was able to prime cellular and humoral immune responses and inducing a higher proliferation index and increased production of specific IgG1/IgG2, which contributed to decrease the bacterial load in both liver and the spleen and improve survival during sepsis. These findings present the first evidence of the effectiveness of whole Ag intranasal-based vaccine administration, which expands the vaccination possibilities against S. aureus infection. PMID:27091687

  11. Anthrax Vaccine Antigen-Adjuvant Formulations Completely Protect New Zealand White Rabbits against Challenge with Bacillus anthracis Ames Strain Spores

    OpenAIRE

    Peachman, Kristina K.; Li, Qin; Matyas, Gary R.; Shivachandra, Sathish B.; Lovchik, Julie; Lyons, Rick C.; Alving, Carl R; Rao, Venigalla B.; Rao, Mangala

    2012-01-01

    In an effort to develop an improved anthrax vaccine that shows high potency, five different anthrax protective antigen (PA)-adjuvant vaccine formulations that were previously found to be efficacious in a nonhuman primate model were evaluated for their efficacy in a rabbit pulmonary challenge model using Bacillus anthracis Ames strain spores. The vaccine formulations include PA adsorbed to Alhydrogel, PA encapsulated in liposomes containing monophosphoryl lipid A, stable liposomal PA oil-in-wa...

  12. Vaccine potential of recombinant antigens of Theileria annulata and Hyalomma anatolicum anatolicum against vector and parasite.

    Science.gov (United States)

    Jeyabal, L; Kumar, Binod; Ray, Debdatta; Azahahianambi, Palavesam; Ghosh, Srikanta

    2012-09-10

    In an attempt to develop vaccine against Hyalomma anatolicum anatolicum and Theileria annulata, three antigens were expressed in prokaryotic expression system and protective potentiality of the antigens was evaluated in cross bred calves. Two groups (grs. 1 and 4) of male cross-bred (Bos indicus × Bos taurus) calves were immunized with rHaa86, a Bm86 ortholog of H. a. anatolicum, while one group of calves (gr. 2) were immunized with cocktails of two antigens viz., surface antigens of T. annulata (rSPAG1, rTaSP). One group each was kept as negative controls (grs. 3 and 5). The animals of groups 1, 2 and 3 were challenged with T. annulata infected H. a. anatolicum adults while the animals of groups 1, 3, 4 and 5 were challenged with uninfected adult ticks. A significantly high (p<0.05) antibody responses to all the three antigens were detected in immunized calves, but the immune response was comparatively higher with rHaa86 followed by rTaSP and rSPAG1. Upon challenge with T. annulata infected ticks, animals of all groups showed symptoms of the disease but there was 50% survival of calves of group 1 while all non immunized control calves (group 3) and rSPAG1+rTaSP immunized calves died. The rHaa86 antigen was found efficacious to protect calves against more than 71.4-75.5% of the challenge infestation. The experiment has given a significant clue towards the development of rHaa86 based vaccine against both H. a. anatolicum and T. annulata. PMID:22546546

  13. Small-angle neutron scattering study of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particle

    Science.gov (United States)

    Sato, M.; Ito, Y.; Kameyama, K.; Imai, M.; Ishikawa, N.; Takagi, T.

    1995-02-01

    The overall and internal structure of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particles was investigated by small-angle neutron scattering using the contrast variation method. The vaccine is a nearly spherical particle, and its contrast-matching point was determined to be at about 24% D 2O content, indicating that a large part of the vaccine particle is occupied by lipids and carbohydrates from the yeast. The Stuhrmann plot suggests that the surface antigens exist predominantly in the peripheral region of the particle, which is favorable to the induction of anti-virus antibodies.

  14. Antigen Presentation Ability of Salmonella Carrying DNA Vaccine Model and MCP-3 gene

    Directory of Open Access Journals (Sweden)

    Endang Winiati Bachtiar

    2015-11-01

    Full Text Available The objective of this study is to determine the antigen presentation ability of a DNA vaccine model that is co-delivered with that of recombinant Salmonella enterica serovar Typhimurium (STM1 expressing chemokine macrophage chemotactic protein-3 (MCP-3. The DNA vaccine, pVROVA, was constructed by amplification of the ovalbumin coding region from sOVA-C1. Dendritic cells (DCs were obtained from IL-4 and GMCSF stimulated mouse bone marrow stem cell. Cultured DCs were incubated with STM1 carrying a model ovalbumin gene (pVROVA. Furthermore, MHC class I antigen presentation of a dominant OVA peptide was assayed in vitro. The experiments were designed to determine the effect of co-delivering MCP-3 with that of ovalbumin in STM1. Our results show that a plasmid pROVA-carrying ovalbumin gene was succesfully constructed and sequence analysis of the ovalbumin-coding revealed an identity match of 100% with that of the chicken ovalbumin DNA sequences from the GenBank database. We also found that the presence of the MCP-3 encoding plasmid in STM1 or E. coli DH1 could increase the recovery of both STM1 and E. coli DH1 over those that carry the empty plasmids. Antigen presentation assay also indicates that MCP-3 can positively influence the presentation of ovalbumin. Conclusion: the infection of DCs by STM1-carrying DNA vaccine and MCP-3 results in an increase of processing and presentation of ovalbumin in vitro.Keywords : DNA vaccine, MCP-3, APC, Salmonella, Dendritic cells

  15. Review of hepatitis B surface antigen-1018 ISS adjuvant-containing vaccine safety and efficacy.

    Science.gov (United States)

    Barry, Mazin; Cooper, Curtis

    2007-11-01

    Existing hepatitis B virus (HBV) vaccines produce seroprotective titers in > 90% of healthy adult recipients following 3 doses administered over 6 months. The durability of this response is variable. Vaccine efficacy is greatly diminished in immune compromised patients. Given the high worldwide prevalence and burden of disease produced by chronic HBV infection, vaccines capable of producing high rates of durable seroprotective HBV surface antibody titers are required. Immunostimulatory sequences (ISS) containing repeating sequences of cytosine phosphoguanosine (CpG) dinucleotide motifs have emerged as useful tools for modulating immune responses. Dynavax Technologies produced a synthetic oligodexynucleotide (ODN) containing these motifs, resulting in an unmethylated cytosine and phosphoguanosine ODN called 1018 ISS. Dynavax's hepatitis B virus vaccine HEPLISAV is comprised of 1018 ISS mixed with recombinant hepatitis B surface antigen. Clinical trials, to date, have shown that HEPLISAV produces rapid, high titer, sustained seroprotection in healthy adults and vaccine hyporesponsive populations. Although additional supporting data are required, this represents a promising strategy to facilitate worldwide HBV prevention efforts. PMID:17961095

  16. Restoration of proliferative response to M. leprae antigens in lepromatous T cells against candidate antileprosy vaccines.

    Science.gov (United States)

    Mustafa, A S

    1996-09-01

    Several studies conducted in the last decade suggest that Mycobacterium lepraereactive T cells exist in lepromatous patients, but their number may be too few to yield a detectable response in cell-mediated immunity (CMI) assays. Immunizations with candidate antileprosy vaccines and stimulation of T cells with M. leprae + interleukin-2 restore the M. leprae-induced CMI response in lepromatous leprosy patients. These immunizations and stimulation may enrich the pre-existing M. leprae-responsive T cells in lepromatous patients and, thereby, induce a detectable CMI response to M. leprae antigens upon repeat testing. To verify this proposition, we carried out a study in a group of 10 lepromatous leprosy patients. Peripheral blood mononuclear cells (PBMC) obtained from these patients were anergic to M. leprae antigens in proliferative assays, but they responded to the antigens of candidate antileprosy vaccines, i.e., M. bovis BCG, M. bovis BCG + M. leprae, and Mycobacterium w. The enrichment of M. leprae-responsive T cells was performed by establishing T-cell lines from the PBMC after in vitro stimulation with M. leprae, M. bovis BCG, M. bovis BCG + M. leprae, and Mycobacterium w. When tested for their proliferative responses, 1/10, 3/10, 6/10 and 2/10 T-cell lines established against M. leprae, M. bovis BCG, M. bovis BCG + M. leprae, and Mycobacterium w, respectively, responded to M. leprae. These results suggest that enrichment of pre-existing M. leprae-responsive T cells may contribute to the restoration of the T-cell response to M. leprae in some lepromatous patients. Four of the 10 M. leprae-induced T-cell lines proliferated in response to the 65 kDa, 36 kDa, 28 kDa, and 12 kDa recombinant antigens of M. leprae, suggesting that the nonresponsiveness of T cells in some lepromatous patients may be overcome by using recombinant antigens of M. leprae. PMID:8862259

  17. A plant-produced protective antigen vaccine confers protection in rabbits against a lethal aerosolized challenge with Bacillus anthracis Ames spores

    OpenAIRE

    Chichester, Jessica A.; Manceva, Slobodanka D; Rhee, Amy; Coffin, Megan V.; Musiychuk, Konstantin; Mett, Vadim; Shamloul, Moneim; Norikane, Joey; Streatfield, Stephen J.; Yusibov, Vidadi

    2013-01-01

    The potential use of Bacillus anthracis as a bioterrorism weapon threatens the security of populations globally, requiring the immediate availability of safe, efficient and easily delivered anthrax vaccine for mass vaccination. Extensive research efforts have been directed toward the development of recombinant subunit vaccines based on protective antigen (PA), the principal virulence factor of B. anthracis. Among the emerging technologies for the production of these vaccine antigens is our la...

  18. Identification of an OmpW homologue in Burkholderia pseudomallei, a protective vaccine antigen against melioidosis.

    Science.gov (United States)

    Casey, William T; Spink, Natasha; Cia, Felipe; Collins, Cassandra; Romano, Maria; Berisio, Rita; Bancroft, Gregory J; McClean, Siobhán

    2016-05-17

    Burkholderia pseudomallei is the causative agent of melioidosis, which is associated with a range of clinical manifestations, including sepsis and fatal pneumonia and is endemic in Southeast Asia and Northern Australia. Treatment can be challenging and control of infection involves prolonged antibiotic therapy, yet there are no approved vaccines available to prevent infection. Our aim was to develop and assess the potential of a prophylactic vaccine candidate targeted against melioidosis. The identified candidate is the 22kDa outer membrane protein, OmpW. We previously demonstrated that this protein was immunoprotective in mouse models of Burkholderia cepacia complex (Bcc) infections. We cloned Bp_ompW in Escherichia coli, expressed and purified the protein. Endotoxin free protein administered with SAS adjuvant protected Balb/C mice (75% survival) relative to controls (25% survival) (p<0.05). A potent serological response was observed with IgG2a to IgG1 ratio of 6.0. Furthermore C57BL/6 mice were protected for up to 80 days against a lethal dose of B. pseudomallei and surpassed the efficacy of the live attenuated 2D2 positive control. BpompW is homologous across thirteen sequenced B. pseudomallei strains, indicating that it should be broadly protective against B. pseudomallei. In conclusion, we have demonstrated that BpOmpW is able to induce protective immunity against melioidosis and is likely to be an effective vaccine antigen, possibly in combination with other subunit antigens. PMID:27091689

  19. Nanogel antigenic protein-delivery system for adjuvant-free intranasal vaccines.

    Science.gov (United States)

    Nochi, Tomonori; Yuki, Yoshikazu; Takahashi, Haruko; Sawada, Shin-ichi; Mejima, Mio; Kohda, Tomoko; Harada, Norihiro; Kong, Il Gyu; Sato, Ayuko; Kataoka, Nobuhiro; Tokuhara, Daisuke; Kurokawa, Shiho; Takahashi, Yuko; Tsukada, Hideo; Kozaki, Shunji; Akiyoshi, Kazunari; Kiyono, Hiroshi

    2010-07-01

    Nanotechnology is an innovative method of freely controlling nanometre-sized materials. Recent outbreaks of mucosal infectious diseases have increased the demands for development of mucosal vaccines because they induce both systemic and mucosal antigen-specific immune responses. Here we developed an intranasal vaccine-delivery system with a nanometre-sized hydrogel ('nanogel') consisting of a cationic type of cholesteryl-group-bearing pullulan (cCHP). A non-toxic subunit fragment of Clostridium botulinum type-A neurotoxin BoHc/A administered intranasally with cCHP nanogel (cCHP-BoHc/A) continuously adhered to the nasal epithelium and was effectively taken up by mucosal dendritic cells after its release from the cCHP nanogel. Vigorous botulinum-neurotoxin-A-neutralizing serum IgG and secretory IgA antibody responses were induced without co-administration of mucosal adjuvant. Importantly, intranasally administered cCHP-BoHc/A did not accumulate in the olfactory bulbs or brain. Moreover, intranasally immunized tetanus toxoid with cCHP nanogel induced strong tetanus-toxoid-specific systemic and mucosal immune responses. These results indicate that cCHP nanogel can be used as a universal protein-based antigen-delivery vehicle for adjuvant-free intranasal vaccination. PMID:20562880

  20. Investigation of the response to the enterobacterial common antigen after typhoid vaccination

    Directory of Open Access Journals (Sweden)

    Arlete M. Milhomem

    1987-03-01

    Full Text Available Antibodies against the Salmonella typhi enterobacterial common antigen (ECA and the O and H antigens were investigated in sera from healthy male subjects who had been previously vaccinated with the typhoid vaccine. No serological response to ECA was observed. Sera from subjects not previously vaccinated presented titers of ECA hemagglutinins which quantitatively were related to the presence ofH titers, but not to O agglutinins but with no statistical significance. The results are discussed in relation to the possible protective immunological mechanisms in typhoid fever.Anticorpos contra o antígeno comum de enterobactérias (ECA bem como contra os antigenos somáticos (O e flagelar (H de Salmonella typhi foram investigados no soro de recrutas do sexo masculino, após a vacinação. Não fo i detectada resposta humoral para ECA. Os soros obtidos antes da vacinação mostraram hemaglutininas para ECA acompanhando a presença de aglutininas para o antígeno H, ao contrário do que se observou em relação ao antígeno O. Discutem-se os resultados quanto ao possível mecanismo da imunoproteção da febre tifóide.

  1. Biological role of surface Toxoplasma gondii antigen in development of vaccine

    Institute of Scientific and Technical Information of China (English)

    Ke-Yi Liu; Dian-Bo Zhang; Qing-Kuan Wei; Jin Li; Gui-Ping Li; Jin-Zhi Yu

    2006-01-01

    AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii (T gondii) in development of vaccine.METHODS: The surface antigen of Tgondii (SAG1)was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1and challenged with lethal strain of T gondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on T gondii tachyzoites under electromicroscope.RESULTS:The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group.The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-γ, IL-2 and IL-4cytokines in mice. In contrast, IL-12, IL-6 and TNF-αwere undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed,swollen, and holes and gaps formed on the surface.CONCLUSION: SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.

  2. Identification of protective and broadly conserved vaccine antigens from the genome of extraintestinal pathogenic Escherichia coli.

    Science.gov (United States)

    Moriel, Danilo Gomes; Bertoldi, Isabella; Spagnuolo, Angela; Marchi, Sara; Rosini, Roberto; Nesta, Barbara; Pastorello, Ilaria; Corea, Vanja A Mariani; Torricelli, Giulia; Cartocci, Elena; Savino, Silvana; Scarselli, Maria; Dobrindt, Ulrich; Hacker, Jörg; Tettelin, Hervé; Tallon, Luke J; Sullivan, Steven; Wieler, Lothar H; Ewers, Christa; Pickard, Derek; Dougan, Gordon; Fontana, Maria Rita; Rappuoli, Rino; Pizza, Mariagrazia; Serino, Laura

    2010-05-18

    Extraintestinal pathogenic Escherichia coli (ExPEC) are a common cause of disease in both mammals and birds. A vaccine to prevent such infections would be desirable given the increasing antibiotic resistance of these bacteria. We have determined the genome sequence of ExPEC IHE3034 (ST95) isolated from a case of neonatal meningitis and compared this to available genome sequences of other ExPEC strains and a few nonpathogenic E. coli. We found 19 genomic islands present in the genome of IHE3034, which are absent in the nonpathogenic E. coli isolates. By using subtractive reverse vaccinology we identified 230 antigens present in ExPEC but absent (or present with low similarity) in nonpathogenic strains. Nine antigens were protective in a mouse challenge model. Some of them were also present in other pathogenic non-ExPEC strains, suggesting that a broadly protective E. coli vaccine may be possible. The gene encoding the most protective antigen was detected in most of the E. coli isolates, highly conserved in sequence and found to be exported by a type II secretion system which seems to be nonfunctional in nonpathogenic strains. PMID:20439758

  3. HA03 as an Iranian Candidate Concealed Antigen for Vaccination against Hyalomma anatolicum anatolicum: Comparative Structural and In silico Studies

    Directory of Open Access Journals (Sweden)

    Mohammadi, A.

    2013-12-01

    Full Text Available In the last decades researchers had focused on developing a vaccine against tick based on protective antigen. Recombinant vaccines based on concealed antigen from Boophilus microplus have been developed in Australia and Cuba by the name of TICKGARD and GAVAC (De La Fuente and Kocan, 2006. Further studies on this antigen have shown some extent of protection against other species (De Vos et al., 2001. In Iran most important species is Hyalomma anatolicum and limited information about its control are available. This paper reports structural and polymorphic analysis of HA03 as an Iranian candidate concealed antigen of H. a. anatolicum deposited in Gen-Bank .(Aghaeipour et al. GQ228820. The comparison between this antigen and other mid gut concealed antigen that their characteristics are available in GenBank showed there are high rate of similarity between them. The HA03 amino acid sequence had a homology of around 89%, 64%, 56% with HA98, BM86, BM95 respectively. Potential of MHC class I and II binding region indicated a considerable variation between BM86 antigen and its efficiency against Iranian H. a. anatolicum. In addition, predicted major of hydrophobisity and similarity in N-glycosylation besides large amount of cystein and seven EGF like regions presented in protein structure revealed that value of HA03 as a new protective antigen and the necessity of the development, BM86 homolog of H. a. anatolicum HA03 based recombinant vaccine.

  4. Sequence Variation and Immunologic Cross-Reactivity among Babesia bovis Merozoite Surface Antigen 1 Proteins from Vaccine Strains and Vaccine Breakthrough Isolates

    Science.gov (United States)

    LeRoith, Tanya; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Hines, Stephen A.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The Babesia bovis merozoite surface antigen 1 (MSA-1) is an immunodominant membrane glycoprotein that is the target of invasion-blocking antibodies. While antigenic variation has been demonstrated in MSA-1 among strains from distinct geographical areas, the extent of sequence variation within a region where it is endemic and the effect of variation on immunologic cross-reactivity have not been assessed. In this study, sequencing of MSA-1 from two Australian B. bovis vaccine strains and 14 breakthrough isolates from vaccinated animals demonstrated low sequence identity in the extracellular region of the molecule, ranging from 19.8 to 46.7% between the T vaccine strain and eight T vaccine breakthrough isolates, and from 18.7 to 99% between the K vaccine strain and six K vaccine breakthrough isolates. Although MSA-1 amino acid sequence varied substantially among strains, overall predicted regions of hydrophilicity and hydrophobicity in the extracellular domain were conserved in all strains examined, suggesting a conserved functional role for MSA-1 despite sequence polymorphism. Importantly, the antigenic variation created by sequence differences resulted in a lack of immunologic cross-reactivity among outbreak strains using sera from animals infected with the B. bovis vaccine strains. Additionally, sera from cattle hyperinfected with the Mexico strain of B. bovis and shown to be clinically immune did not cross-react with MSA-1 from any other isolate tested. The results indicate that isolates of B. bovis capable of evading vaccine-induced immunity contain an msa-1 gene that is significantly different from the msa-1 of the vaccine strain, and that the difference can result in a complete lack of cross-reactivity between MSA-1 from vaccine and breakthrough strains in immunized animals. PMID:16113254

  5. Assessing the relationship between antigenicity and immunogenicity of human rabies vaccines when administered by intradermal route: results of a metaanalysis.

    Science.gov (United States)

    Sudarshan, Mysore K; Gangaboraiah, Bilagumba; Ravish, Haradanahalli S; Narayana, Doddabele H Ashwath

    2010-07-01

    The metadata of 10 published studies and 3 vaccine trial reports comprising of 19 vaccine cohorts from four countries conducted over a period of 23 years (1986 - 2009) was used for metaanalysis. The vaccines studied were purified chick embryo cell vaccine (Rabipur, India & Germany), purified vero cell rabies vaccine (Verorab, France; Indirab, India) & human diploid cell vaccine (MIRV, France).The potency of these vaccines varied from 0.55 IU to 2.32 IU per intradermal dose of 0.1 ml per site. The vaccines were administered to 1,011 subjects comprising of 19 cohorts and using five different ID regimens. The immunogenicity was measured by assays of rabies virus neutralizing antibody (RVNA) titres using rapid fluorescent focus inhibition test (RFFIT) [15 cohorts] and mouse neutralization test (MNT) [4 cohorts]. The statistical analysis of the data was done by Karl Pearson's correlation coefficient to measure the relationship between antigenicity and immunogenicity. It was revealed that, there was no significant linear relationship between antigenicity and immunogenicity of rabies vaccines when administered by intradermal route. (p> 0.230 and p>0.568). PMID:20523131

  6. Immunogenic and antigenic activity of an experimental oral rabies vaccine prepared from the strain Vnukovo-32/107.

    Science.gov (United States)

    Svrcek, S; Durove, A; Ondrejka, R; Závadová, J; Süliová, J; Benísek, Z; Vrtiak, O J; Feketeová, J; Mad'ar, M

    1995-03-01

    The immunogenic and antigenic activity of an experimental live oral rabies vaccine prepared from the strain Vnukovo-32/107 was evaluated on the basis of results obtained in 3 sets of experiments. These were carried out as model experiments on white mice, then on target animals--red foxes (Vulpes vulpes) and a related species--farm-bred polar foxes (Alopex lagopus). For quantitative determination of the immunogenic activity of the orally or subcutaneously administered rabies vaccines in model experiments on mice a method was used that had been developed in our laboratory. Antibodies were detected and quantified by an ELISA kit that had also been developed in our lab. Tenacity of the experimental vaccine (infectious tissue culture medium after yolk addition) was verified at different temperatures; the effects of storage temperature upon virus titre and immunogenic activity were investigated. An important part of the experiments--evaluation of the antigenic and immunogenic activity of the live vaccine at oral vaccination (vaccination baits, conditions simulating field vaccination) was carried out in foxes. The immunogenic activity (challenge experiments with a street virus on day 180 and 360 after vaccination) was evaluated in common foxes (Vulpes vulpes). The results document a high immunogenic and antigenic activity of the experimental live oral rabies vaccine. The strain Vnukovo-32/107 is suitable for the industrial manufacturing of vaccination baits. In the target species--common foxes challenged on day 180 after primovaccination an 83% protection was observed. Challenge on day 180 after revaccination (or day 360 after primovaccination), the orally immunized foxes proved to be 100% protected. For parallel evaluation of the immunogenic activity of an oral vaccine and for antibody titration it is recommended to employ the quantitative mice test and an ELISA technique, respectively. PMID:7762124

  7. Rapid and sustained CD4(+) T-cell-independent immunity from adenovirus-encoded vaccine antigens

    DEFF Research Database (Denmark)

    Holst, Peter J; Bartholdy, Christina; Buus, Anette Stryhn;

    2007-01-01

    absence of CD4(+) T-cell help were sustained in the long term and able to expand and control a secondary challenge with LCMV. Our results demonstrate that modifications to the antigen used in adenovirus vaccines may be used to improve the induced T-cell response. Such a strategy for CD4(+) T-cell...... elicited with an adenovirus-encoded minimal epitope covalently linked to beta(2)-microglobulin. We demonstrate that the beta(2)-microglobulin-linked epitope induced an accelerated and augmented CD8(+) T-cell response. Furthermore, the immunity conferred by vaccination with beta(2)-microglobulin......-linked lymphocytic choriomeningitis virus (LCMV)-derived epitopes was long-lived and protective. Notably, in contrast to full-length protein, the response elicited with the beta(2)-microglobulin-linked LCMV-derived epitope was CD4(+) T-cell independent. Furthermore, virus-specific CD8(+) T cells primed in the...

  8. The role of Plasmodium falciparum variant surface antigens in protective immunity and vaccine development

    DEFF Research Database (Denmark)

    Hviid, Lars

    2010-01-01

    There is substantial immuno-epidemiological evidence that the parasite-encoded, so-called variant surface antigens (VSAs), such as PfEMP1 on the surface of infected erythrocytes (IEs) are important-in some cases probably decisive determinants of clinical outcome of P. falciparum malaria. The...... evidence is increasingly being underpinned by specific molecular understanding of the pathogenic processes involved. Pregnancy-associated malaria (PAM) caused by placenta-sequestering IEs expressing the PfEMP1 variant VAR2CSA is a particularly striking example of this. These findings have raised hopes that...... development of PfEMP1-based vaccines to protect specifically against severe malaria syndromes-in particular PAM-is feasible. This review summarizes the evidence that VSAs are important targets of NAI, discusses why VSA-based vaccines might be feasible despite the extensive intra- and interclonal variation of...

  9. Identification and evaluation of vaccine candidate antigens from the poultry red mite (Dermanyssus gallinae).

    Science.gov (United States)

    Bartley, Kathryn; Wright, Harry W; Huntley, John F; Manson, Erin D T; Inglis, Neil F; McLean, Kevin; Nath, Mintu; Bartley, Yvonne; Nisbet, Alasdair J

    2015-11-01

    An aqueous extract of the haematophagous poultry ectoparasite, Dermanyssus gallinae, was subfractionated using anion exchange chromatography. Six of these subfractions were used to immunise hens and the blood from these hens was fed, in vitro, to poultry red mites. Mite mortality following these feeds was indicative of protective antigens in two of the subfractions, with the risks of mites dying being 3.1 and 3.7 times higher than in the control group (P<0.001). A combination of two-dimensional immunoblotting and immunoaffinity chromatography, using IgY from hens immunised with these subfractions, was used in concert with proteomic analyses to identify the strongest immunogenic proteins in each of these subfractions. Ten of the immunoreactive proteins were selected for assessment as vaccine candidates using the following criteria: intensity of immune recognition; likelihood of exposure of the antigen to the antibodies in a blood meal; proposed function and known vaccine potential of orthologous molecules. Recombinant versions of each of these 10 proteins were produced in Escherichia coli and were used to immunise hens. Subsequent in vitro feeding of mites on blood from these birds indicated that immunisation with Deg-SRP-1 (serpin), Deg-VIT-1 (vitellogenin), Deg-HGP-1 (hemelipoglycoprotein) or Deg-PUF-1 (a protein of unknown function) resulted in significantly increased risk of mite death (1.7-2.8times higher than in mites fed blood from control hens immunised with adjuvant only, P<0.001). The potential for using these antigens in a recombinant vaccine is discussed. PMID:26296690

  10. Prior infection with influenza virus but not vaccination leaves a long-term immunological imprint that intensifies the protective efficacy of antigenically drifted vaccine strains.

    Science.gov (United States)

    Kim, Jin Hyang; Liepkalns, Justine; Reber, Adrian J; Lu, Xiuhua; Music, Nedzad; Jacob, Joshy; Sambhara, Suryaprakash

    2016-01-20

    The role of pre-existing immunity for influenza vaccine responses is of great importance for public health, and thus has been studied in various contexts, yet the impact of differential priming on vaccine responses in the midst of antigenic drift remains to be elucidated. To address this with antigenically related viruses, mice were first primed by either infection or immunization with A/Puerto Rico/8/34 (PR8) virus, then immunized with whole-inactivated A/Fort Monmouth/1/47 (FM1) virus. The ensuing vaccine responses and the protective efficacy of FM1 were superior in PR8 infection-primed mice compared to PR8 immunization-primed or unprimed mice. Increased FM1-specific Ab responses of PR8 infection-primed mice also broadened cross-reactivity against contemporary as well as antigenically more drifted strains. Further, prior infection heightened the protective efficacy of antigenically distant strains, such as A/Brisbane/59/2006 infection followed by immunization with split pandemic H1N1 vaccine (A/California/07/2009). Therefore, influenza infection is a significant priming event that intensifies future vaccine responses against drift strains. PMID:26706277

  11. A recombinant raccoon poxvirus vaccine expressing both Yersinia pestis F1 and truncated V antigens protects animals against lethal plague.

    Science.gov (United States)

    Rocke, Tonie E.; Kingstad-Bakke, B; Berlier, W; Osorio, J.E.

    2014-01-01

    In previous studies, we demonstrated in mice and prairie dogs that simultaneous administration of two recombinant raccoon poxviruses (rRCN) expressing Yersinia pestis antigens (F1 and V307-a truncated version of the V protein) provided superior protection against plague challenge compared to individual single antigen constructs. To reduce costs of vaccine production and facilitate implementation of a sylvatic plague vaccine (SPV) control program for prairie dogs, a dual antigen construct is more desirable. Here we report the construction and characterization of a novel RCN-vectored vaccine that simultaneously expresses both F1 and V307 antigens. This dual antigen vaccine provided similar levels of protection against plague in both mice and prairie dogs as compared to simultaneous administration of the two single antigen constructs and was also shown to protect mice against an F1 negative strain of Y. pestis.. The equivalent safety, immunogenicity and efficacy profile of the dual RCN-F1/V307 construct warrants further evaluation in field efficacy studies in sylvatic plague endemic areas.

  12. A Recombinant Raccoon Poxvirus Vaccine Expressing both Yersinia pestis F1 and Truncated V Antigens Protects Animals against Lethal Plague.

    Science.gov (United States)

    Rocke, Tonie E; Kingstad-Bakke, Brock; Berlier, Willy; Osorio, Jorge E

    2014-01-01

    In previous studies, we demonstrated in mice and prairie dogs that simultaneous administration of two recombinant raccoon poxviruses (rRCN) expressing Yersinia pestis antigens (F1 and V307-a truncated version of the V protein) provided superior protection against plague challenge compared to individual single antigen constructs. To reduce costs of vaccine production and facilitate implementation of a sylvatic plague vaccine (SPV) control program for prairie dogs, a dual antigen construct is more desirable. Here we report the construction and characterization of a novel RCN-vectored vaccine that simultaneously expresses both F1 and V307 antigens. This dual antigen vaccine provided similar levels of protection against plague in both mice and prairie dogs as compared to simultaneous administration of the two single antigen constructs and was also shown to protect mice against an F1 negative strain of Y. pestis. The equivalent safety, immunogenicity and efficacy profile of the dual RCN-F1/V307 construct warrants further evaluation in field efficacy studies in sylvatic plague endemic areas. PMID:26344891

  13. A Recombinant Raccoon Poxvirus Vaccine Expressing both Yersinia pestis F1 and Truncated V Antigens Protects Animals against Lethal Plague

    Directory of Open Access Journals (Sweden)

    Tonie E. Rocke

    2014-10-01

    Full Text Available In previous studies, we demonstrated in mice and prairie dogs that simultaneous administration of two recombinant raccoon poxviruses (rRCN expressing Yersinia pestis antigens (F1 and V307—a truncated version of the V protein provided superior protection against plague challenge compared to individual single antigen constructs. To reduce costs of vaccine production and facilitate implementation of a sylvatic plague vaccine (SPV control program for prairie dogs, a dual antigen construct is more desirable. Here we report the construction and characterization of a novel RCN-vectored vaccine that simultaneously expresses both F1 and V307 antigens. This dual antigen vaccine provided similar levels of protection against plague in both mice and prairie dogs as compared to simultaneous administration of the two single antigen constructs and was also shown to protect mice against an F1 negative strain of Y. pestis. The equivalent safety, immunogenicity and efficacy profile of the dual RCN-F1/V307 construct warrants further evaluation in field efficacy studies in sylvatic plague endemic areas.

  14. Pentamers not found in the universal proteome can enhance antigen specific immune responses and adjuvant vaccines.

    Science.gov (United States)

    Patel, Ami; Dong, Jessica C; Trost, Brett; Richardson, Jason S; Tohme, Sarah; Babiuk, Shawn; Kusalik, Anthony; Kung, Sam K P; Kobinger, Gary P

    2012-01-01

    Certain short peptides do not occur in humans and are rare or non-existent in the universal proteome. Antigens that contain rare amino acid sequences are in general highly immunogenic and may activate different arms of the immune system. We first generated a list of rare, semi-common, and common 5-mer peptides using bioinformatics tools to analyze the UniProtKB database. Experimental observations indicated that rare and semi-common 5-mers generated stronger cellular responses in comparison with common-occurring sequences. We hypothesized that the biological process responsible for this enhanced immunogenicity could be used to positively modulate immune responses with potential application for vaccine development. Initially, twelve rare 5-mers, 9-mers, and 13-mers were incorporated in frame at the end of an H5N1 hemagglutinin (HA) antigen and expressed from a DNA vaccine. The presence of some 5-mer peptides induced improved immune responses. Adding one 5-mer peptide exogenously also offered improved clinical outcome and/or survival against a lethal H5N1 or H1N1 influenza virus challenge in BALB/c mice and ferrets, respectively. Interestingly, enhanced anti-HBsAg antibody production by up to 25-fold in combination with a commercial Hepatitis B vaccine (Engerix-B, GSK) was also observed in BALB/c mice. Mechanistically, NK cell activation and dependency was observed with enhancing peptides ex vivo and in NK-depleted mice. Overall, the data suggest that rare or non-existent oligopeptides can be developed as immunomodulators and supports the further evaluation of some 5-mer peptides as potential vaccine adjuvants. PMID:22937099

  15. Pentamers not found in the universal proteome can enhance antigen specific immune responses and adjuvant vaccines.

    Directory of Open Access Journals (Sweden)

    Ami Patel

    Full Text Available Certain short peptides do not occur in humans and are rare or non-existent in the universal proteome. Antigens that contain rare amino acid sequences are in general highly immunogenic and may activate different arms of the immune system. We first generated a list of rare, semi-common, and common 5-mer peptides using bioinformatics tools to analyze the UniProtKB database. Experimental observations indicated that rare and semi-common 5-mers generated stronger cellular responses in comparison with common-occurring sequences. We hypothesized that the biological process responsible for this enhanced immunogenicity could be used to positively modulate immune responses with potential application for vaccine development. Initially, twelve rare 5-mers, 9-mers, and 13-mers were incorporated in frame at the end of an H5N1 hemagglutinin (HA antigen and expressed from a DNA vaccine. The presence of some 5-mer peptides induced improved immune responses. Adding one 5-mer peptide exogenously also offered improved clinical outcome and/or survival against a lethal H5N1 or H1N1 influenza virus challenge in BALB/c mice and ferrets, respectively. Interestingly, enhanced anti-HBsAg antibody production by up to 25-fold in combination with a commercial Hepatitis B vaccine (Engerix-B, GSK was also observed in BALB/c mice. Mechanistically, NK cell activation and dependency was observed with enhancing peptides ex vivo and in NK-depleted mice. Overall, the data suggest that rare or non-existent oligopeptides can be developed as immunomodulators and supports the further evaluation of some 5-mer peptides as potential vaccine adjuvants.

  16. Immunogenicity and safety of hepatitis E vaccine in healthy hepatitis B surface antigen positive adults

    OpenAIRE

    Wu, Ting; Huang, Shou-Jie; Zhu, Feng-Cai; Zhang, Xue-Feng; AI, XING; Yan, Qiang; Wang, Zhong-Ze; Yang, Chang-Lin; Jiang, Han-Min; Liu, Xiao-Hui; Guo, Meng; Du, Hai-Lian; Ng, Mun-Hon; Zhang, Jun; Xia, Ningshao

    2013-01-01

    A recombinant hepatitis E vaccine, Hecolin®, has been proven safe and effective in healthy adults. As hepatitis B surface antigen (HBsAg) positive individuals have a higher risk of poor prognosis after super-infection with hepatitis E virus (HEV), the safety and immunogenicity of Hecolin® in this population should be assessed. The present study is an extending analysis of data from a large randomized controlled clinical trial of Hecolin®. Healthy participants (n = 14,065) without current or p...

  17. Tumor Radiation Therapy Creates Therapeutic Vaccine Responses to the Colorectal Cancer Antigen GUCY2C

    Energy Technology Data Exchange (ETDEWEB)

    Witek, Matthew [Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Blomain, Erik S.; Magee, Michael S.; Xiang, Bo; Waldman, Scott A. [Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Snook, Adam E., E-mail: adam.snook@jefferson.edu [Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania (United States)

    2014-04-01

    Purpose: Radiation therapy (RT) is thought to produce clinical responses in cancer patients, not only through direct toxicity to cancer cells and supporting tumor stroma cells, but also through activation of immunologic effectors. More recently, RT has potentiated the local and systemic effects of cancer immunotherapy (IT). However, combination regimens that maximize immunologic and clinical efficacy remain undefined. Methods and Materials: We evaluated the impact of local RT on adenoviral-mediated vaccination against the colorectal cancer antigen GUCY2C (Ad5-GUCY2C) in a murine subcutaneous tumor model using mouse CT26 colon cancer cells (CT26-GUCY2C). Immune responses were assessed by ELISpot, and clinical responses were assessed by tumor size and incidence. Results: The specific sequence of tumor-directed RT preceding Ad5-GUCY2C IT transformed inactive therapeutic Ad5-GUCY2C vaccination into a curative vaccine. GUCY2C-specific T cell responses were amplified (P<.05), tumor eradication was maximized (P<.01), and tumor volumes were minimized (P<.001) in mice whose tumors were irradiated before, compared with after, Ad5-GUCY2C vaccination. The immunologic and antitumor efficacy of Ad5-GUCY2C was amplified comparably by unfractionated (8 Gy × 1), or biologically equivalent doses of fractionated (3.5 Gy × 3), RT. The antitumor effects of sequential RT and IT (RT-IT) depended on expression of GUCY2C by tumor cells and the adenoviral vaccine vector, and tumor volumes were inversely related to the magnitude of GUCY2C-specific T cell responses. Moreover, mice cured of CT26-GUCY2C tumors by RT-IT showed long-lasting antigen-dependent protection, resisting tumors formed by GUCY2C-expressing 4T1 breast cancer cells inoculated 50 days after CT26 cells. Conclusions: Optimal sequencing of RT and IT amplifies antigen-specific local and systemic immune responses, revealing novel acute and long-term therapeutic antitumor protection. These observations underscore the importance

  18. Tumor Radiation Therapy Creates Therapeutic Vaccine Responses to the Colorectal Cancer Antigen GUCY2C

    International Nuclear Information System (INIS)

    Purpose: Radiation therapy (RT) is thought to produce clinical responses in cancer patients, not only through direct toxicity to cancer cells and supporting tumor stroma cells, but also through activation of immunologic effectors. More recently, RT has potentiated the local and systemic effects of cancer immunotherapy (IT). However, combination regimens that maximize immunologic and clinical efficacy remain undefined. Methods and Materials: We evaluated the impact of local RT on adenoviral-mediated vaccination against the colorectal cancer antigen GUCY2C (Ad5-GUCY2C) in a murine subcutaneous tumor model using mouse CT26 colon cancer cells (CT26-GUCY2C). Immune responses were assessed by ELISpot, and clinical responses were assessed by tumor size and incidence. Results: The specific sequence of tumor-directed RT preceding Ad5-GUCY2C IT transformed inactive therapeutic Ad5-GUCY2C vaccination into a curative vaccine. GUCY2C-specific T cell responses were amplified (P<.05), tumor eradication was maximized (P<.01), and tumor volumes were minimized (P<.001) in mice whose tumors were irradiated before, compared with after, Ad5-GUCY2C vaccination. The immunologic and antitumor efficacy of Ad5-GUCY2C was amplified comparably by unfractionated (8 Gy × 1), or biologically equivalent doses of fractionated (3.5 Gy × 3), RT. The antitumor effects of sequential RT and IT (RT-IT) depended on expression of GUCY2C by tumor cells and the adenoviral vaccine vector, and tumor volumes were inversely related to the magnitude of GUCY2C-specific T cell responses. Moreover, mice cured of CT26-GUCY2C tumors by RT-IT showed long-lasting antigen-dependent protection, resisting tumors formed by GUCY2C-expressing 4T1 breast cancer cells inoculated 50 days after CT26 cells. Conclusions: Optimal sequencing of RT and IT amplifies antigen-specific local and systemic immune responses, revealing novel acute and long-term therapeutic antitumor protection. These observations underscore the importance

  19. Monitoring antigenic variations of enterovirus 71: implications for virus surveillance and vaccine development.

    Directory of Open Access Journals (Sweden)

    Min-Yuan Chia

    2014-07-01

    Full Text Available Enterovirus 71 (EV71 causes life-threatening epidemics in Asia and can be phylogenetically classified into three major genogroups (A ∼ C including 11 genotypes (A, B1 ∼ B5, and C1 ∼ C5. Recently, EV71 epidemics occurred cyclically in Taiwan with different genotypes. In recent years, human studies using post-infection sera obtained from children have detected antigenic variations among different EV71 strains. Therefore, surveillance of enterovirus 71 should include phylogenetic and antigenic analysis. Due to limitation of sera available from children with EV71 primary infection, suitable animal models should be developed to generate a panel of antisera for monitoring EV71 antigenic variations. Twelve reference strains representing the 11 EV71 genotypes were grown in rhabdomyosarcoma cells. Infectious EV71 particles were purified and collected to immunize rabbits. The rabbit antisera were then employed to measure neutralizing antibody titers against the 12 reference strains and 5 recent strains. Rabbits immunized with genogroup B and C viruses consistently have a lower neutralizing antibody titers against genogroup A (≧ 8-fold difference and antigenic variations between genogroup B and C viruses can be detected but did not have a clear pattern, which are consistent with previous human studies. Comparison between human and rabbit neutralizing antibody profiles, the results showed that ≧ 8-fold difference in rabbit cross-reactive antibody ratios could be used to screen EV71 isolates for identifying potential antigenic variants. In conclusion, a rabbit model was developed to monitor antigenic variations of EV71, which are critical to select vaccine strains and predict epidemics.

  20. Neutralizing antibody and functional mapping of Bacillus anthracis protective antigen-The first step toward a rationally designed anthrax vaccine.

    Science.gov (United States)

    McComb, Ryan C; Martchenko, Mikhail

    2016-01-01

    Anthrax is defined by the Centers for Disease Control and Prevention as a Category A pathogen for its potential use as a bioweapon. Current prevention treatments include Anthrax Vaccine Adsorbed (AVA). AVA is an undefined formulation of Bacillus anthracis culture supernatant adsorbed to aluminum hydroxide. It has an onerous vaccination schedule, is slow and cumbersome to produce and is slightly reactogenic. Next-generation vaccines are focused on producing recombinant forms of anthrax toxin in a well-defined formulation but these vaccines have been shown to lose potency as they are stored. In addition, studies have shown that a proportion of the antibody response against these vaccines is focused on non-functional, non-neutralizing regions of the anthrax toxin while some essential functional regions are shielded from eliciting an antibody response. Rational vaccinology is a developing field that focuses on designing vaccine antigens based on structural information provided by neutralizing antibody epitope mapping, crystal structure analysis, and functional mapping through amino acid mutations. This information provides an opportunity to design antigens that target only functionally important and conserved regions of a pathogen in order to make a more optimal vaccine product. This review provides an overview of the literature related to functional and neutralizing antibody epitope mapping of the Protective Antigen (PA) component of anthrax toxin. PMID:26611201

  1. A novel virus-like particle based vaccine platform displaying the placental malaria antigen VAR2CSA

    DEFF Research Database (Denmark)

    Thrane, Susan; Janitzek, Christoph M; Agerbæk, Mette Ø;

    2015-01-01

    failed during clinical testing, virus-like particle (VLP) based vaccines (e.g., the licensed human papillomavirus vaccines) have demonstrated high efficacy, suggesting that the spatial assembly of the vaccine antigen is a critical parameter for inducing an optimal long-lasting protective immune response......Placental malaria caused by Plasmodium falciparum is a major cause of mortality and severe morbidity. Clinical testing of a soluble protein-based vaccine containing the parasite ligand, VAR2CSA, has been initiated. VAR2CSA binds to the human receptor chondroitin sulphate A (CSA) and is responsible...... for sequestration of Plasmodium falciparum infected erythrocytes in the placenta. It is imperative that a vaccine against malaria in pregnancy, if administered to women before they become pregnant, can induce a strong and long lasting immune response. While most soluble protein-based vaccines have...

  2. A Novel Virus-Like Particle Based Vaccine Platform Displaying the Placental Malaria Antigen VAR2CSA.

    Directory of Open Access Journals (Sweden)

    Susan Thrane

    Full Text Available Placental malaria caused by Plasmodium falciparum is a major cause of mortality and severe morbidity. Clinical testing of a soluble protein-based vaccine containing the parasite ligand, VAR2CSA, has been initiated. VAR2CSA binds to the human receptor chondroitin sulphate A (CSA and is responsible for sequestration of Plasmodium falciparum infected erythrocytes in the placenta. It is imperative that a vaccine against malaria in pregnancy, if administered to women before they become pregnant, can induce a strong and long lasting immune response. While most soluble protein-based vaccines have failed during clinical testing, virus-like particle (VLP based vaccines (e.g., the licensed human papillomavirus vaccines have demonstrated high efficacy, suggesting that the spatial assembly of the vaccine antigen is a critical parameter for inducing an optimal long-lasting protective immune response. We have developed a VLP vaccine display platform by identifying regions of the HPV16 L1 coat protein where a biotin acceptor site (AviTagTM can be inserted without compromising VLP-assembly. Subsequent biotinylation of Avi-L1 VLPs allow us to anchor monovalent streptavidin (mSA-fused proteins to the biotin, thereby obtaining a dense and repetitive VLP-display of the vaccine antigen. The mSA-VAR2CSA antigen was delivered on the Avi-L1 VLP platform and tested in C57BL/6 mice in comparison to two soluble protein-based vaccines consisting of naked VAR2CSA and mSA-VAR2CSA. The mSA-VAR2CSA Avi-L1 VLP and soluble mSA-VAR2CSA vaccines induced higher antibody titers than the soluble naked VAR2CSA vaccine after three immunizations. The VAR2CSA Avi-L1 VLP vaccine induced statistically significantly higher endpoint titres compared to the soluble mSA-VAR2CSA vaccine, after 1st and 2nd immunization; however, this difference was not statistically significant after 3rd immunization. Importantly, the VLP-VAR2CSA induced antibodies were functional in inhibiting the binding of

  3. A Novel Virus-Like Particle Based Vaccine Platform Displaying the Placental Malaria Antigen VAR2CSA.

    Science.gov (United States)

    Thrane, Susan; Janitzek, Christoph M; Agerbæk, Mette Ø; Ditlev, Sisse B; Resende, Mafalda; Nielsen, Morten A; Theander, Thor G; Salanti, Ali; Sander, Adam F

    2015-01-01

    Placental malaria caused by Plasmodium falciparum is a major cause of mortality and severe morbidity. Clinical testing of a soluble protein-based vaccine containing the parasite ligand, VAR2CSA, has been initiated. VAR2CSA binds to the human receptor chondroitin sulphate A (CSA) and is responsible for sequestration of Plasmodium falciparum infected erythrocytes in the placenta. It is imperative that a vaccine against malaria in pregnancy, if administered to women before they become pregnant, can induce a strong and long lasting immune response. While most soluble protein-based vaccines have failed during clinical testing, virus-like particle (VLP) based vaccines (e.g., the licensed human papillomavirus vaccines) have demonstrated high efficacy, suggesting that the spatial assembly of the vaccine antigen is a critical parameter for inducing an optimal long-lasting protective immune response. We have developed a VLP vaccine display platform by identifying regions of the HPV16 L1 coat protein where a biotin acceptor site (AviTagTM) can be inserted without compromising VLP-assembly. Subsequent biotinylation of Avi-L1 VLPs allow us to anchor monovalent streptavidin (mSA)-fused proteins to the biotin, thereby obtaining a dense and repetitive VLP-display of the vaccine antigen. The mSA-VAR2CSA antigen was delivered on the Avi-L1 VLP platform and tested in C57BL/6 mice in comparison to two soluble protein-based vaccines consisting of naked VAR2CSA and mSA-VAR2CSA. The mSA-VAR2CSA Avi-L1 VLP and soluble mSA-VAR2CSA vaccines induced higher antibody titers than the soluble naked VAR2CSA vaccine after three immunizations. The VAR2CSA Avi-L1 VLP vaccine induced statistically significantly higher endpoint titres compared to the soluble mSA-VAR2CSA vaccine, after 1st and 2nd immunization; however, this difference was not statistically significant after 3rd immunization. Importantly, the VLP-VAR2CSA induced antibodies were functional in inhibiting the binding of parasites to CSA

  4. Expression of HIV-1 antigens in plants as potential subunit vaccines

    Directory of Open Access Journals (Sweden)

    Tanzer Fiona L

    2008-06-01

    Full Text Available Abstract Background Human immunodeficiency virus type 1 (HIV-1 has infected more than 40 million people worldwide, mainly in sub-Saharan Africa. The high prevalence of HIV-1 subtype C in southern Africa necessitates the development of cheap, effective vaccines. One means of production is the use of plants, for which a number of different techniques have been successfully developed. HIV-1 Pr55Gag is a promising HIV-1 vaccine candidate: we compared the expression of this and a truncated Gag (p17/p24 and the p24 capsid subunit in Nicotiana spp. using transgenic plants and transient expression via Agrobacterium tumefaciens and recombinant tobamovirus vectors. We also investigated the influence of subcellular localisation of recombinant protein to the chloroplast and the endoplasmic reticulum (ER on protein yield. We partially purified a selected vaccine candidate and tested its stimulation of a humoral and cellular immune response in mice. Results Both transient and transgenic expression of the HIV antigens were successful, although expression of Pr55Gag was low in all systems; however, the Agrobacterium-mediated transient expression of p24 and p17/p24 yielded best, to more than 1 mg p24/kg fresh weight. Chloroplast targeted protein levels were highest in transient and transgenic expression of p24 and p17/p24. The transiently-expressed p17/p24 was not immunogenic in mice as a homologous vaccine, but it significantly boosted a humoral and T cell immune response primed by a gag DNA vaccine, pTHGagC. Conclusion Transient agroinfiltration was best for expression of all of the recombinant proteins tested, and p24 and p17/p24 were expressed at much higher levels than Pr55Gag. Our results highlight the usefulness of plastid signal peptides in enhancing the production of recombinant proteins meant for use as vaccines. The p17/p24 protein effectively boosted T cell and humoral responses in mice primed by the DNA vaccine pTHGagC, showing that this plant

  5. Bacterial antigen expression is an important component in inducing an immune response to orally administered Salmonella-delivered DNA vaccines.

    Directory of Open Access Journals (Sweden)

    Michelle E Gahan

    Full Text Available BACKGROUND: The use of Salmonella to deliver heterologous antigens from DNA vaccines is a well-accepted extension of the success of oral Salmonella vaccines in animal models. Attenuated S. typhimurium and S. typhi strains are safe and efficacious, and their use to deliver DNA vaccines combines the advantages of both vaccine approaches, while complementing the limitations of each technology. An important aspect of the basic biology of the Salmonella/DNA vaccine platform is the relative contributions of prokaryotic and eukaryotic expression in production of the vaccine antigen. Gene expression in DNA vaccines is commonly under the control of the eukaryotic cytomegalovirus (CMV promoter. The aim of this study was to identify and disable putative bacterial promoters within the CMV promoter and evaluate the immunogenicity of the resulting DNA vaccine delivered orally by S. typhimurium. METHODOLOGY/PRINCIPAL FINDINGS: The results reported here clearly demonstrate the presence of bacterial promoters within the CMV promoter. These promoters have homology to the bacterial consensus sequence and functional activity. To disable prokaryotic expression from the CMV promoter a series of genetic manipulations were performed to remove the two major bacterial promoters and add a bacteria transcription terminator downstream of the CMV promoter. S. typhimurium was used to immunise BALB/c mice orally with a DNA vaccine encoding the C-fragment of tetanus toxin (TT under control of the original or the modified CMV promoter. Although both promoters functioned equally well in eukaryotic cells, as indicated by equivalent immune responses following intramuscular delivery, only the original CMV promoter was able to induce an anti-TT specific response following oral delivery by S. typhimurium. CONCLUSIONS: These findings suggest that prokaryotic expression of the antigen and co-delivery of this protein by Salmonella are at least partially responsible for the successful

  6. Evidence for the utility of the Bm86 antigen from Boophilus microplus in vaccination against other tick species.

    Science.gov (United States)

    de Vos, S; Zeinstra, L; Taoufik, O; Willadsen, P; Jongejan, F

    2001-01-01

    The Bm86 antigen, as originally identified in Boophilus microplus, is the basis of commercial tick vaccines against this tick species. The potential for using this antigen or homologues of the antigen in vaccination against other tick species has been assessed. We have conducted vaccine trials in cattle using the B. microplus-derived recombinant Bm86 vaccine (TickGARD) using pairs of vaccinated calves and control calves. These were infested with B. microplus and Boophilus decoloratus larvae simultaneously. For both species, the numbers of engorged female adult ticks, their weight and egg-laying capacity were all reduced, leading to a reduction in reproductive capacity of 74% for B. microplus and 70% for B. decoloratus. Hyalomma anatolicum anatolicum ticks were fed both as immatures as well as adults on vaccinated calves and non-vaccinated controls. There was an overall 50% reduction in the total weight of nymphs engorging on vaccinated calves, and a suggestion of a subsequent effect on feeding adults. For Hyalomma dromedarii there was a 95% reduction in the number of nymphs engorging and a further 55% reduction in weight of those ticks surviving. Rhipicephalus appendiculatus and Amblyomma variegatum ticks were fed simultaneously both as immatures and subsequently as adults. There was no evidence for a significant vaccination effect. Finally, the amino acid sequence of a Bm86 homologue found in H. a. anatolicum unequivocally demonstrated the conservation of this molecule in this species. Our strategy for the development of multivalent anti-tick vaccines is discussed in relation to these findings. PMID:11523920

  7. Membrane and envelope virus proteins co-expressed as lysosome associated membrane protein (LAMP) fused antigens: a potential tool to develop DNA vaccines against flaviviruses

    OpenAIRE

    Rafael Dhalia; Milton Maciel Jr.; Fábia S.P. Cruz; Isabelle F.T. Viana; Mariana L. Palma; Thomas August; Ernesto T.A. Marques Jr.

    2009-01-01

    Vaccination is the most practical and cost-effective strategy to prevent the majority of the flavivirus infection to which there is an available vaccine. However, vaccines based on attenuated virus can potentially promote collateral side effects and even rare fatal reactions. Given this scenario, the developent of alternative vaccination strategies such as DNA-based vaccines encoding specific flavivirus sequences are being considered. Endogenous cytoplasmic antigens, characteristically plasmi...

  8. Molecular Design and Immunogenicity of a Multiple-epitope FMDV Antigen and DNA Vaccination

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This article reports the design and construction of a multiple-epitope foot and mouth disease virus (FMDV)antigen, designated as OAAT. This recombinant antigen consists of the structural protein VP1 genes from serotypes A and O FMDV, five major VP1 immunodominant epitopes from two genotypes of Asia1 serotype, and three Th2 epitopes originating from the nonstructural protein, three ABC gene and structural protein VP4 gene. Expressions of target gene from these plasmids in HeLa cells were verified by Western-blot. BALB/c mice were immunized intramuscularly with the DNA vaccines thrice every two weeks. We found that pA could induce simultaneously specific antibodies against serotypes A, Asia1, and O FMDV. Compared to those of the controls, the spots of FMDV-specific IFN-γ and cytotoxic activity from mice immunized with pA were significantly increased. pA provided full protection in 2/4 guinea pigs from challenge with FMDV O/NY00 and Asia1/YNBS/58, respectively. The results show that although pA did not give full protection in 100% immunized guinea pigs from challenge with type O and Asia1 FMDV, respectively, OAAT may be potential immunogen against FMDV and pA may be potential DNA vaccines against FMDV.

  9. Amiloride enhances antigen specific CTL by faciliting HBV DNA vaccine entry into cells.

    Directory of Open Access Journals (Sweden)

    Shuang Geng

    Full Text Available The induction of relatively weak immunity by DNA vaccines in humans can be largely attributed to the low efficiency of transduction of somatic cells. Although formulation with liposomes has been shown to enhance DNA transduction of cultured cells, little, if any, effect is observed on the transduction of somatic tissues and cells. To improve the rate of transduction, DNA vaccine delivery by gene gun and the recently developed electroporation techniques have been employed. We report here that to circumvent requirement for such equipment, amiloride, a drug that is prescribed for hypertension treatment, can accelerate plasmid entry into antigen presenting cells (APCs both in vitro and in vivo. The combination induced APCs more dramatically in both maturation and cytokine secretion. Amiloride enhanced development of full CD8 cytolytic function including induction of high levels of antigen specific CTL and expression of IFN-γ+perforin+granzymeB+ in CD8+ T cells. Thus, amiloride is a facilitator for DNA transduction into host cells which in turn enhances the efficiency of the immune responses.

  10. Synthesis and Evaluation of Glycoconjugates Comprising N-Acyl-Modified Thomsen-Friedenreich Antigens as Anticancer Vaccines.

    Science.gov (United States)

    Sun, Shuang; Zheng, Xiu-Jing; Huo, Chang-Xin; Song, Chengcheng; Li, Qin; Ye, Xin-Shan

    2016-05-19

    Thomsen-Friedenreich (TF) antigen is an important tumor-associated carbohydrate antigen. Its low immunogenicity, however, limits its application in the development of anticancer vaccines. To solve this problem, several N-acyl-modified TF derivatives were synthesized and conjugated with carrier protein CRM197 (a mutated diphtheria toxoid cross-reactive material). The immunological results in BALB/c mice demonstrated that these modified TF antigen conjugates could stimulate the production of higher titers of IgG antibodies that cross-reacted with native TF antigen. These glycoconjugates showed strong lymphocyte proliferative response, suggesting that they can induce cellular immunity. Furthermore, the elicited antisera reacted strongly with TF-positive tumor cells (4T1). In particular, the N-monofluoroacetyl-modified TF conjugate 4-CRM197 showed the strongest complement-dependent cytotoxicity effect against 4T1 cells, implying the potential of this glycoconjugate as an anticancer vaccine. PMID:27075633

  11. Prophylaxis and Therapy of Inhalational Anthrax by a Novel Monoclonal Antibody to Protective Antigen That Mimics Vaccine-Induced Immunity

    OpenAIRE

    Vitale, Laura; Blanset, Diann; Lowy, Israel; O'Neill, Thomas; Goldstein, Joel; Little, Stephen F.; Andrews, Gerard P.; Dorough, Gary; Taylor, Ronald K.; Keler, Tibor

    2006-01-01

    The neutralizing antibody response to the protective antigen (PA) component of anthrax toxin elicited by approved anthrax vaccines is an accepted correlate for vaccine-mediated protection against anthrax. We reasoned that a human anti-PA monoclonal antibody (MAb) selected on the basis of superior toxin neutralization activity might provide potent protection against anthrax. The fully human MAb (also referred to as MDX-1303 or Valortim) was chosen from a large panel of anti-PA human MAbs gener...

  12. Serological Correlate of Protection in Guinea Pigs for a Recombinant Protective Antigen Anthrax Vaccine Produced from Bacillus brevis

    OpenAIRE

    Chun, Jeong-Hoon; Choi, On-Jee; Cho, Min-Hee; Hong, Kee-Jong; Seong, Won Keun; Oh, Hee-Bok; Rhie, Gi-eun

    2012-01-01

    Objective Recombinant protective antigen (rPA) is the active pharmaceutical ingredient of a second generation anthrax vaccine undergoing clinical trials both in Korea and the USA. By using the rPA produced from Bacillus brevis pNU212 expression system, correlations of serological immune response to anthrax protection efficacy were analyzed in a guinea pig model. Methods Serological responses of rPA anthrax vaccine were investigated in guinea pigs that were given single or two injections (inte...

  13. Impact of Acute Malaria on Pre-Existing Antibodies to Viral and Vaccine Antigens in Mice and Humans

    OpenAIRE

    Banga, Simran; Coursen, Jill D.; Portugal, Silvia; Tran, Tuan M.; Hancox, Lisa; Ongoiba, Aissata; Traore, Boubacar; Doumbo, Ogobara K.; Huang, Chiung-Yu; Harty, John T.; Crompton, Peter D.

    2015-01-01

    Vaccine-induced immunity depends on long-lived plasma cells (LLPCs) that maintain antibody levels. A recent mouse study showed that Plasmodium chaubaudi infection reduced pre-existing influenza-specific antibodies—raising concerns that malaria may compromise pre-existing vaccine responses. We extended these findings to P. yoelii infection, observing decreases in antibodies to model antigens in inbred mice and to influenza in outbred mice, associated with LLPC depletion and increased susceptib...

  14. Aromatic-dependent salmonella as anti-bacterial vaccines and as presenters of heterologous antigens or of DNA encoding them.

    Science.gov (United States)

    Stocker, B A

    2000-09-29

    The development of live bacterial vaccines is reviewed, in particular aromatic-dependent Salmonella, either for protection against the corresponding infections (including typhoid fever) or as carrier-presenter of antigens of unrelated pathogens or of DNA specifying them. Aromatic-dependent Salmonella live vaccines are also compared with BCG and Ty21a and the recent records of exceptional situations are discussed in which aroA (deletion) strains of Salmonella typhimurium cause progressive disease in mice. PMID:11000459

  15. Increasing a Robust Antigen-Specific Cytotoxic T Lymphocyte Response by FMDV DNA Vaccination with IL-9 Expressing Construct

    OpenAIRE

    Qiang Zou; Bing Wu; Xiaodan He; Yizhi Zhang; Youmin Kang; Jin Jin; Hanqian Xu; Hu Liu; Bin Wang

    2010-01-01

    Various chemokines and cytokines as adjuvants can be used to improve efficacy of DNA vaccination. In this study, we sought to investigate if a DNA construct expressing IL-9 (designed as proV-IL9) as a molecular adjuvant enhance antigen specific immune responses elicited by the pcD-VP1 DNA vaccination. Mice immunized with pcD-VP1 combined with proV-IL9 developed a strong humoral response. In addition, the coinoculation induced significant higher level of antigen-specific cell proliferation and...

  16. Successful kidney transplantation from a hepatitis B surface antigen-positive donor to an antigen-negative recipient using a novel vaccination regimen.

    Science.gov (United States)

    Singh, Gurmukteshwar; Hsia-Lin, Andrea; Skiest, Daniel; Germain, Michael; O'Shea, Michael; Braden, Gregory

    2013-04-01

    Transplanting a kidney from a hepatitis B surface antigen (HBsAg)-positive donor to an HBsAg-negative recipient who is naturally immune has been successful in countries endemic for hepatitis B virus (HBV). However, in most of these cases, the donors were deceased. We present a report of a successful HBsAg-discordant kidney transplantation in the United States; in this case, a living donor kidney was transplanted to a vaccinated recipient. The wife of a 58-year-old HBsAg-negative man volunteered to donate a kidney to her husband. She had chronic hepatitis B but undetectable HBV DNA. She tested positive for HBsAg and antibody to hepatitis B core antigen, but hepatitis B e antigen was undetectable. The recipient failed to develop an antibody response to 3 doses of intramuscular recombinant HBV vaccine given in consecutive months. Immunity was induced by using biweekly intradermal vaccine. However, antibody titer tapered to vaccine resulted in a prolonged anamnestic response, allowing for successful living unrelated donor transplantation. During the 10 years since transplantation, the patient has continued to have normal liver function, with undetectable HBsAg and HBV DNA. Antibody titers to HBsAg slowly decreased to 5.8 mIU/mL during the 10 years. Transplant function has been well preserved. This approach to inducing long-term immunity for transplantation merits further study in the United States. PMID:23219109

  17. Subdominant antigens in bacterial vaccines: Am779 is subdominant in the anaplasma marginale outer membrane vaccine but does not associate with protective immunity

    Science.gov (United States)

    Identification of specific antigens responsible for the ability of complex immunogens to induce protection is a major goal in development of bacterial vaccines. Much of the investigation has focused on highly abundant and highly immunodominant outer membrane proteins. Recently however, genomic and p...

  18. Enhanced immune stimulation by a therapeutic lymphoma tumor antigen vaccine produced in insect cells involves mannose receptor targeting to antigen presenting cells.

    Science.gov (United States)

    Betting, David J; Mu, Xi Y; Kafi, Kamran; McDonnel, Desmond; Rosas, Francisco; Gold, Daniel P; Timmerman, John M

    2009-01-01

    Therapeutic vaccination of lymphoma patients with tumor-specific immunoglobulin (idiotype, Id) coupled to the carrier protein keyhole limpet hemocyanin (Id-KLH) is undergoing clinical investigation, and methods to improve the immunogenicity of these and other protein tumor antigen vaccines are being sought. Id proteins can be produced via tumor-myeloma hybridomas or recombinant methods in mammalian, bacteria, or insect cells. We now demonstrate that terminal mannose residues, characteristic of recombinant proteins produced in insect cells, yield Id proteins with significantly enhanced immunostimulatory properties compared to Id proteins derived from mammalian cells. Recombinant baculovirus-infected insect cell-derived Id showed higher binding to and activation of human dendritic cells mediated by mannose receptors. In vivo, insect cell-derived Id elicited higher levels of tumor-specific CD8+ cytotoxic T lymphocyte (CTL) and improved eradication of pre-established murine lymphoma. Insect cell and mammalian Id generated similar levels of tumor-specific antibodies, showing no impairment in antibody responses to native tumor antigen despite the glycoslylation differences in the immunogen. Combining insect cell production and maleimide-based KLH conjugation offered the highest levels of anti-tumor immunity. Our data comparing sources of recombinant Id protein tumor antigens used in therapeutic cancer vaccines demonstrate that insect cell-derived antigens can offer several immunologic advantages over proteins derived from mammalian sources. PMID:19000731

  19. Mimotope-based vaccines of Leishmania infantum antigens and their protective efficacy against visceral leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Lourena Emanuele Costa

    Full Text Available BACKGROUND: The development of cost-effective prophylactic strategies to prevent leishmaniasis has become a high-priority. The present study has used the phage display technology to identify new immunogens, which were evaluated as vaccines in the murine model of visceral leishmaniasis (VL. Epitope-based immunogens, represented by phage-fused peptides that mimic Leishmania infantum antigens, were selected according to their affinity to antibodies from asymptomatic and symptomatic VL dogs' sera. METHODOLOGY/MAIN FINDINGS: Twenty phage clones were selected after three selection cycles, and were evaluated by means of in vitro assays of the immune stimulation of spleen cells derived from naive and chronically infected with L. infantum BALB/c mice. Clones that were able to induce specific Th1 immune response, represented by high levels of IFN-γ and low levels of IL-4 were selected, and based on their selectivity and specificity, two clones, namely B10 and C01, were further employed in the vaccination protocols. BALB/c mice vaccinated with clones plus saponin showed both a high and specific production of IFN-γ, IL-12, and GM-CSF after in vitro stimulation with individual clones or L. infantum extracts. Additionally, these animals, when compared to control groups (saline, saponin, wild-type phage plus saponin, or non-relevant phage clone plus saponin, showed significant reductions in the parasite burden in the liver, spleen, bone marrow, and paws' draining lymph nodes. Protection was associated with an IL-12-dependent production of IFN-γ, mainly by CD8+ T cells, against parasite proteins. These animals also presented decreased parasite-mediated IL-4 and IL-10 responses, and increased levels of parasite-specific IgG2a antibodies. CONCLUSIONS/SIGNIFICANCE: This study describes two phage clones that mimic L. infantum antigens, which were directly used as immunogens in vaccines and presented Th1-type immune responses, and that significantly reduced the

  20. Identification and characterization of profilin antigen among Babesia species as a common vaccine candidate against babesiosis.

    Science.gov (United States)

    Munkhjargal, Tserendorj; Aboge, Gabriel Oluga; Ueno, Akio; Aboulaila, Mahmoud; Yokoyama, Naoaki; Igarashi, Ikuo

    2016-07-01

    We have characterized a member of the profilin (PROF) family protein as a common antigen in three pathogens-Babesia bovis (B. bovis), Babesia bigemina (B. bigemina), and Babesia microti (B. microti)-and evaluated its immunogenic and cross-protective properties against a challenge infection with B. microti in BALB/c mice. The recombinant PROF proteins of B. bovis, B. bigemina, and B. microti were successfully expressed in Escherichia coli (E. coli) as soluble GST fusion proteins (rBboPROF, rBbigPROF, and rBmPROF, respectively), and they were found to be antigenic. On probing with mouse anti-rPROF serum, green fluorescence was observed on the parasites' cytosols by confocal laser microscopy. Immunization regimes in BALB/c mice using rPROFs induced cross-protective immunity against B. microti infection based on high levels of cytokines and immunoglobulin (IgG) titers, a reduction in peak parasitemia levels, and earlier clearance of the parasite as compared with control mice. The findings of the present study indicate that PROF is a common antigen among bovine and murine Babesia parasites, and it might be used as a common vaccine candidate against babesiosis. PMID:27003460

  1. Infection with Plasmodium berghei Boosts Antibody Responses Primed by a DNA Vaccine Encoding Gametocyte Antigen Pbs48/45

    OpenAIRE

    Haddad, Diana; Maciel, Jorge; Kumar, Nirbhay

    2006-01-01

    An important consideration in the development of a malaria vaccine for individuals living in areas of endemicity is whether vaccine-elicited immune responses can be boosted by natural infection. To investigate this question, we used Plasmodium berghei ANKA blood-stage parasites for the infection of mice that were previously immunized with a DNA vaccine encoding the P. berghei sexual-stage antigen Pbs48/45. Intramuscular immunization in mice with one or two doses of DNA-Pbs48/45 or of empty DN...

  2. A Delayed Type Hypersensitivity (DTH) Skin Reaction to Hepatitis B Surface Antigen (HBsAg) and Intradermal Hepatitis B Vaccination

    OpenAIRE

    Nagafuchi, Seiho; Kashiwagi, Seizaburo; Hayashi, Jun; Katsuta, Hitoshi; Ikematsu, Hideyuki; Harada, Mine

    2004-01-01

    The significance of a delayed type hypersensitivity skin reaction to hepatitis B surface antigen (HBsAg) (HBs-DTH) in type B viral hepatitis (VHB) and in intradermal hepatitis B (HB) vaccination is reviewed. HBs-DTH could be developed by the intradermal injection of HB vaccine in anti-HBs positive people and also in persons immunized with HB vaccine. Thus, HBs-DTH could serve as a useful marker for the acquisition of an active Thl type immunoreactivity to HBsAg. HBs-DTH was absent in patients...

  3. Application of radionuclide techniques in the characterization of antigens for vaccine development against the human malaria parasite Plasmodium falciparum

    International Nuclear Information System (INIS)

    The development of molecular vaccines against the human malaria parasite Plasmodium falciparum requires the characterization of putative protective antigens. The characterization and structural analyses of the small amounts of antigens present in the parasite is made possible by the use of radiolabelled amino acids, monosaccharides and lipids. Parasite proliferation assays, used to identify antibodies that inhibit parasite growth in vitro, utilize radiolabelled hypoxanthine. The determination of T cell epitopes is dependent on measuring lymphocyte proliferation with radiolabelled thymidine. Radiolabelled antibodies are routinely used in Western blots and epitope analysis. The use of these techniques is illustrated in the characterization of two new merozoite surface antigens. (author). 40 refs, 11 figs

  4. Antigen

    Science.gov (United States)

    An antigen is any substance that causes your immune system to produce antibodies against it. This means your immune ... and is trying to fight it off. An antigen may be a substance from the environment, such ...

  5. Mucosal vaccine delivery of antigens tightly bound to an adjuvant particle made from food-grade bacteria

    NARCIS (Netherlands)

    van Roosmalen, ML; Kanninga, R; El Khattabi, M; Neef, J; Audouy, S; Bosma, T; Kuipers, A; Post, E; Steen, A; Kok, J; Buist, G; Kuipers, OP; Robillard, G; Leenhouts, K

    2006-01-01

    Mucosal immunization with subunit vaccines requires new types of antigen delivery vehicles and adjuvants for optimal immune responses. We have developed a non-living and non-genetically modified gram-positive bacterial delivery particle (GEM) that has built-in adjuvant activity and a high loading ca

  6. Gold nanocluster-based vaccines for dual-delivery of antigens and immunostimulatory oligonucleotides

    Science.gov (United States)

    Tao, Yu; Zhang, Yan; Ju, Enguo; Ren, Hui; Ren, Jinsong

    2015-07-01

    We here report a facile one-pot synthesis of fluorescent gold nanoclusters (AuNCs) via the peptide biomineralization method, which can elicit specific immunological responses. The as-prepared peptide-protected AuNCs (peptide-AuNCs) display strong red fluorescence, and more importantly, as compared to the peptide alone, the immune stimulatory ability of the resulting peptide-AuNCs can not only be retained, but can also be efficaciously enhanced. Moreover, through a dual-delivery of antigen peptides and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (ODNs), the as-prepared peptide-AuNC-CpG conjugates can also act as smart self-vaccines to assist in the generation of high immunostimulatory activity, and be applied as a probe for intracellular imaging. Both in vitro and in vivo studies provide strong evidence that the AuNC-based vaccines may be utilized as safe and efficient immunostimulatory agents that are able to prevent and/or treat a variety of ailments.We here report a facile one-pot synthesis of fluorescent gold nanoclusters (AuNCs) via the peptide biomineralization method, which can elicit specific immunological responses. The as-prepared peptide-protected AuNCs (peptide-AuNCs) display strong red fluorescence, and more importantly, as compared to the peptide alone, the immune stimulatory ability of the resulting peptide-AuNCs can not only be retained, but can also be efficaciously enhanced. Moreover, through a dual-delivery of antigen peptides and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (ODNs), the as-prepared peptide-AuNC-CpG conjugates can also act as smart self-vaccines to assist in the generation of high immunostimulatory activity, and be applied as a probe for intracellular imaging. Both in vitro and in vivo studies provide strong evidence that the AuNC-based vaccines may be utilized as safe and efficient immunostimulatory agents that are able to prevent and/or treat a variety of ailments. Electronic supplementary information (ESI

  7. Differences in immune responses against Leishmania induced by infection and by immunization with killed parasite antigen: implications for vaccine discovery.

    Science.gov (United States)

    Mendonça, Sergio C F

    2016-01-01

    The leishmaniases are a group of diseases caused by different species of the protozoan genus Leishmania and transmitted by sand fly vectors. They are a major public health problem in almost all continents. There is no effective control of leishmaniasis and its geographical distribution is expanding in many countries. Great effort has been made by many scientists to develop a vaccine against leishmaniasis, but, so far, there is still no effective vaccine against the disease. The only way to generate protective immunity against leishmaniasis in humans is leishmanization, consisting of the inoculation of live virulent Leishmania as a means to acquire long-lasting immunity against subsequent infections. At present, all that we know about human immune responses to Leishmania induced by immunization with killed parasite antigens came from studies with first generation candidate vaccines (killed promastigote extracts). In the few occasions that the T cell-mediated immune responses to Leishmania induced by infection and immunization with killed parasite antigens were compared, important differences were found both in humans and in animals. This review discusses these differences and their relevance to the development of a vaccine against leishmaniasis, the major problems involved in this task, the recent prospects for the selection of candidate antigens and the use of attenuated Leishmania as live vaccines. PMID:27600664

  8. Cytokines Expression Profile and Kinetics of Peste des petits ruminants Virus Antigen and Antibody in Infected and Vaccinated Goats

    Institute of Scientific and Technical Information of China (English)

    Arun Patel; Kaushal Kishor Rajak; Vinayagamurthy Balamurugan; Arnab Sen; Shashi Bhusan Sudhakar; Veerakyathappa Bhanuprakash; Raj Kumar Singh; Awadh Bihari Pandey

    2012-01-01

    The present study deals with the co-ordination of cytokine(IL-4 and IFN-γ) expression and kinetics of peste des petits ruminants(PPR) virus antigen and antibody in PPRV infected and vaccinated goats.The infected animals exhibited mixed cytokine(both TH1 and TH2) responses in the initial phase of the disease.The infected and dead goats had increased IFN-γ response before their death; while IL-4 remained at the base level.The cytokine expression in recovered animals was almost similar to that of vaccinated ones,where a unique biphasic response of IL-4 expression was observed with an up-regulation of IFN-γ on 7th days post vaccination(dpv).Analysis of PPR virus antigen and antibody kinetics in different components of blood from infected and vaccinated animals revealed that the PPR virus antigen load was highest in plasma followed by serum and blood of the infected animals,whereas vaccinated animals showed only marginal positivity on 9th dpv.The antibody titer was high in serum followed by plasma and blood in both vaccinated and infected animals.Therefore,it is inferred that the presence of antigen and antibody were significant with the expression of cytokine,and that a decreased response of IL-4 was noticed during intermediate phase of the disease i.e.,7 to 12th days post infection(dpi).This indicates the ability to mount a functional TH2 response after 14th dpi could be a critical determinant in deciding the survival of the PPR infected animal.

  9. Presentation of peptides from Bacillus anthracis protective antigen on Tobacco Mosaic Virus as an epitope targeted anthrax vaccine.

    Science.gov (United States)

    McComb, Ryan C; Ho, Chi-Lee; Bradley, Kenneth A; Grill, Laurence K; Martchenko, Mikhail

    2015-11-27

    The current anthrax vaccine requires improvements for rapidly invoking longer-lasting neutralizing antibody responses with fewer doses from a well-defined formulation. Designing antigens that target neutralizing antibody epitopes of anthrax protective antigen, a component of anthrax toxin, may offer a solution for achieving a vaccine that can induce strong and long lasting antibody responses with fewer boosters. Here we report implementation of a strategy for developing epitope focused virus nanoparticle vaccines against anthrax by using immunogenic virus particles to present peptides derived from anthrax toxin previously identified in (1) neutralizing antibody epitope mapping studies, (2) toxin crystal structure analyses to identify functional regions, and (3) toxin mutational analyses. We successfully expressed two of three peptide epitopes from anthrax toxin that, in previous reports, bound antibodies that were partially neutralizing against toxin activity, discovered cross-reactivity between vaccine constructs and toxin specific antibodies raised in goats against native toxin and showed that antibodies induced by our vaccine constructs also cross-react with native toxin. While protection against intoxication in cellular and animal studies were not as effective as in previous studies, partial toxin neutralization was observed in animals, demonstrating the feasibility of using plant-virus nanoparticles as a platform for epitope defined anthrax vaccines. PMID:26514421

  10. Development of hepatitis C virus vaccine using hepatitis B core antigen as immuno-carrier

    Institute of Scientific and Technical Information of China (English)

    Jia-Yu Chen; Fan Li

    2006-01-01

    AIM: To develop hepatitis C virus (HCV) vaccine using HBcAg as the immuno-carrier to express HCV T epitope and to investigate its immunogenicity in mice.METHODS: We constructed the plasmid pTrc-coreNheI using gene engineering technique, constructed the pcDNA3.1-coreNheI-GFP plasmid with GFP as the reporter gene, and transfected them into Hela cells.The expression of GFP was observed under confocal microscopy and the feasibility of using HBcAg as an immuno-carrier vaccine was studied. pTrc-core gene with a synthetic T epitope antigen gene of HCV (35-44aa) was fused and expressed in the plasmid pTrccore-HCV (T). For the fusion of the HBcAg-T protein,sucrose, density gradient centrifugation was used, and its molecular weight and purity were analyzed by SDSPAGE. Then balb/c mice were immunized by the plasmid with the HBcAg (expressed by pTrc-core) protein as control. The tumor regression potential was investigated in mice and evaluated at appropriate time. After three times of immunization, the peripheral blood and spleen of vaccinated mice were collected. HBcAb was detected by ELISA, and nonspecific T lymphocyte proliferation and response of splenocytes were respectively examined by MTT assay. T cell subset of blood and spleen were detected by FACS.RESULTS: GFP was successfully expressed. Tumor regression trial showed that no tumor formation was found in the group receiving immunization, while tumor xenograft progression was not changed in the control group. Strong nonspecific lymphocyte proliferation response was induced. FACS also showed that the ratio of CD8+T cells in the experimental group was higher than the controls, but the serum HBcAb in experimental group was similar to the control.CONCLUSION: HBcAg can be used as an immunocarrier of vaccine, the fusion of HBcAg-T protein could induce stronger cellular immune responses and it might be a candidate for therapeutic vaccines specific for HCV.

  11. Development of multiple sclerosis after vaccination against hepatitis B: a study based on human leucocyte antigen haplotypes.

    Science.gov (United States)

    Ozakbas, S; Idiman, E; Yulug, B; Pakoz, B; Bahar, H; Gulay, Z

    2006-09-01

    The aetiology of multiple sclerosis (MS) is still not fully understood. Infectious agents are believed to play a role in the development of this multifactorial disease. Cases in which this disease occurs after administration of both plasma-derived and recombinant hepatitis B vaccines have been reported. In this study, we compared a group of 11 MS patients who developed first clinical symptoms after hepatitis B vaccination (group I) with 71 MS patients who were never vaccinated against hepatitis B and were negative for hepatitis B serology (group II), and 20 healthy controls (group III). Mean age was 27.75 years (19-39) in group I, 30.16 years (18-50) in group II, and 34.4 years (18-50) in group III. Mean attack rate after 2 years was 1.5 in group I and 1.63 in group II. Mean Expanded Disability Status Scale score after 2 years was 1.31 in group I and 1.89 in group II. Human leucocyte antigen (HLA) typing and serology for hepatitis B surface antigen were performed in all groups. In groups I and II, HLA-DR2 was more frequent than in normal healthy subjects. This reflects the general role of HLA in the pathogenesis of MS but suggests that antigen presentation by different HLA is not involved in the development of MS after hepatitis B vaccination. Since there was no difference in the clinical features between vaccinated and nonvaccinated MS patients, this study supports recent reports that hepatitis B vaccination is safe in MS patients and that hepatitis B vaccination is not involved in the development of MS. PMID:16948644

  12. Immunostimulating complexes incorporating Eimeria tenella antigens and plant saponins as effective delivery system for coccidia vaccine immunization.

    Science.gov (United States)

    Berezin, V E; Bogoyavlenskiy, A P; Tolmacheva, V P; Makhmudova, N R; Khudyakova, S S; Levandovskaya, S V; Omirtaeva, E S; Zaitceva, I A; Tustikbaeva, G B; Ermakova, O S; Aleksyuk, P G; Barfield, R C; Danforth, H D; Fetterer, R H

    2008-04-01

    Immunostimulating complexes (ISCOMs) are unique, multimolecular structures formed by encapsulating antigens, lipids, and triterpene saponins of plant origin, and are an effective delivery system for various kinds of antigens. The uses of ISCOMs formulated with saponins from plants collected in Kazakhstan, with antigens from the poultry coccidian parasite Eimeria tenella, were evaluated for their potential use in developing a vaccine for control of avian coccidiosis. Saponins isolated from the plants Aesculus hippocastanum and Glycyrrhiza glabra were partially purified by HPLC. The saponin fractions obtained from HPLC were evaluated for toxicity in chickens and chicken embryos. The HPLC saponin fractions with the least toxicity, compared to a commercial saponin Quil A, were used to assemble ISCOMs. When chicks were immunized with ISCOMs prepared with saponins from Kazakhstan plants and E. tenella antigens, and then challenged with E. tenella oocysts, significant protection was conveyed compared to immunization with antigen alone. The results of this study indicate that ISCOMs formulated with saponins isolated from plants indigenous to Kazakhstan are an effective antigen delivery system which may be successfully used, with low toxicity, for preparation of highly immunogenic coccidia vaccine. PMID:18564738

  13. Multi-antigen vaccines based on complex adenovirus vectors induce protective immune responses against H5N1 avian influenza viruses.

    Science.gov (United States)

    Holman, David H; Wang, Danher; Raja, Nicholas U; Luo, Min; Moore, Kevin M; Woraratanadharm, Jan; Mytle, Nutan; Dong, John Y

    2008-05-19

    There are legitimate concerns that the highly pathogenic H5N1 avian influenza virus could adapt for human-to-human transmission and cause a pandemic similar to the 1918 "Spanish flu" that killed 50 million people worldwide. We have developed pandemic influenza vaccines by incorporating multiple antigens from both avian and Spanish influenza viruses into complex recombinant adenovirus vectors. In vaccinated mice, these vaccines induced strong humoral and cellular immune responses against pandemic influenza virus antigens, and protected vaccinated mice against lethal H5N1 virus challenge. These results indicate that this multi-antigen, broadly protective vaccine may serve as a safer and more effective approach than traditional methods for development of a pandemic influenza vaccine. PMID:18395306

  14. The characteristics exosporium antigens from different vaccine strains of bacillus antracis

    International Nuclear Information System (INIS)

    To develop of both test-systems for rapid detection and identification of B. anthracis spores and a new subunit vaccine the antigens on the spore surface should be characterized. Exosporium consists of two layers-basal and peripheral and has been form by protein, amino- and neutral polysaccharides, lipids and ash. Number of anthrax exosporium proteins was described and identified: glycoprotein BclA, BclB, alanine racemase, inosine hydrolase, glycosyl hydrolase, superoxid dismutase, ExsF, ExsY, ExsK,CotB,CotY and SoaA. So far no glycosylated proteins other then highly immunogenic glycoproteins BclA, BclB were detected in the B. anthracis spore extract although several exosporium-specific glycoprotein have been described in other members of the B.cereus family- B. thuringiensis and B. cereus. Although EA1 protein originally described as main component of S-layer from vegetative cells he can regular observed in different exosporium preparations and additionally some anti- EA1 monoclonal antibodies able to recognize spore surface. We have revealed that EA1 isolated from spore of Russians strain STI-1contain carbohydrate which determine immunogenicity of this antigen. Because some time ago we have found that exosporium protein's pattern variable among B. anthracis strains we investigated exosporium from spore of different strains of B. anthracis including STI-1, Ames, Stern and others. We have comparative characterized antigens by using Western Blotting, Two-Dimensional electrophoresis and Mass Spec analysis. The results of analysis will be presented and discussed.(author)

  15. Multiple antigens of Yersinia pestis delivered by live recombinant attenuated Salmonella vaccine strains elicit protective immunity against plague.

    Science.gov (United States)

    Sanapala, Shilpa; Rahav, Hannah; Patel, Hetal; Sun, Wei; Curtiss, Roy

    2016-05-01

    Based on our improved novel Salmonella vaccine delivery platform, we optimized the recombinant attenuated Salmonella typhimurium vaccine (RASV) χ12094 to deliver multiple Yersinia pestis antigens. These included LcrV196 (amino acids, 131-326), Psn encoded on pYA5383 and F1 encoded in the chromosome, their synthesis did not cause adverse effects on bacterial growth. Oral immunization with χ12094(pYA5383) simultaneously stimulated high antibody titers to LcrV, Psn and F1 in mice and presented complete protection against both subcutaneous (s.c.) and intranasal (i.n.) challenges with high lethal doses of Y. pestis CO92. Moreover, no deaths or other disease symptoms were observed in SCID mice orally immunized with χ12094(pYA5383) over a 60-day period. Therefore, the trivalent S. typhimurium-based live vaccine shows promise for a next-generation plague vaccine. PMID:27060051

  16. Comparative analysis of antigen-targeting sequences used in DNA vaccines.

    Science.gov (United States)

    Carvalho, Joana A; Azzoni, Adriano R; Prazeres, Duarte M F; Monteiro, Gabriel A

    2010-03-01

    Plasmid vectors can be optimized by including specific signals that promote antigen targeting to the major antigen presentation and processing pathways, increasing the immunogenicity and potency of DNA vaccines. A pVAX1-based backbone was used to encode the Green Fluorescence Protein (GFP) reporter gene fused either to ISG (Invariant Surface Glycoprotein) or to TSA (trans-sialidase) Trypanosoma brucei genes. The plasmids were further engineered to carry antigen-targeting sequences, which promote protein transport to the extracellular space (secretion signal), lysosomes (LAMP-1) and to the endoplasmic reticulum (adenovirus e1a). Transfection efficiency was not affected by differences in the size between each construct as no differences in the plasmid copy number per cell were found. This finding also suggests that the addition of both ISG gene and targeting sequences did not add sensitive regions prone to nuclease attack to the plasmid. Cells transfected with pVAX1GFP had a significant higher number of transcripts. This could be a result of lower mRNA stability and/or a lower transcription rate associated with the bigger transcripts. On the other hand, no differences were found between transcript levels of each ISG-GFP plasmids. Therefore, the addition of these targeting sequences does not affect the maturation/stability of the transcripts. Microscopy analysis showed differences in protein localization and fluorescent levels of cells transfected with pVAX1GFP and ISG constructs. Moreover, cells transfected with the lamp and secretory sequences presented a distinct distribution pattern when compared with ISG protein. Protein expression was quantified by flow cytometry. Higher cell fluorescence was observed in cells expressing the cytoplasmic fusion protein (ISG-GFP or TSA-GFP) compared with cells where the protein was transported to the lysosomal pathway. Protein transport to the endoplasmic reticulum does not lead to a decrease in the mean fluorescence values. The

  17. Removing N-terminal sequences in pre-S1 domain enhanced antibody and B-cell responses by an HBV large surface antigen DNA vaccine.

    Science.gov (United States)

    Ge, Guohong; Wang, Shixia; Han, Yaping; Zhang, Chunhua; Lu, Shan; Huang, Zuhu

    2012-01-01

    Although the use of recombinant hepatitis B virus surface (HBsAg) protein vaccine has successfully reduced global hepatitis B infection, there are still a number of vaccine recipients who do not develop detectable antibody responses. Various novel vaccination approaches, including DNA vaccines, have been used to further improve the coverage of vaccine protection. Our previous studies demonstrated that HBsAg-based DNA vaccines could induce both humoral and CMI responses in experimental animal models. However, one form of the the HBsAg antigen, the large S antigen (HBs-L), expressed by DNA vaccine, was not sufficiently immunogenic in eliciting antibody responses. In the current study, we produced a modified large S antigen DNA vaccine, HBs-L(T), which has a truncated N-terminal sequence in the pre-S1 region. Compared to the original HBs-L DNA vaccine, the HBs-L(T) DNA vaccine improved secretion in cultured mammalian cells and generated significantly enhanced HBsAg-specific antibody and B cell responses. Furthermore, this improved HBsL DNA vaccine, along with other HBsAg-expressing DNA vaccines, was able to maintain predominantly Th1 type antibody responses while recombinant HBsAg protein vaccines produced in either yeast or CHO cells elicited mostly Th2 type antibody responses. Our data indicate that HBsAg DNA vaccines with improved immunogenicity offer a useful alternative choice to recombinant protein-based HBV vaccines, particularly for therapeutic purposes against chronic hepatitis infection where immune tolerance led to poor antibody responses to S antigens. PMID:22844502

  18. Removing N-terminal sequences in pre-S1 domain enhanced antibody and B-cell responses by an HBV large surface antigen DNA vaccine.

    Directory of Open Access Journals (Sweden)

    Guohong Ge

    Full Text Available Although the use of recombinant hepatitis B virus surface (HBsAg protein vaccine has successfully reduced global hepatitis B infection, there are still a number of vaccine recipients who do not develop detectable antibody responses. Various novel vaccination approaches, including DNA vaccines, have been used to further improve the coverage of vaccine protection. Our previous studies demonstrated that HBsAg-based DNA vaccines could induce both humoral and CMI responses in experimental animal models. However, one form of the the HBsAg antigen, the large S antigen (HBs-L, expressed by DNA vaccine, was not sufficiently immunogenic in eliciting antibody responses. In the current study, we produced a modified large S antigen DNA vaccine, HBs-L(T, which has a truncated N-terminal sequence in the pre-S1 region. Compared to the original HBs-L DNA vaccine, the HBs-L(T DNA vaccine improved secretion in cultured mammalian cells and generated significantly enhanced HBsAg-specific antibody and B cell responses. Furthermore, this improved HBsL DNA vaccine, along with other HBsAg-expressing DNA vaccines, was able to maintain predominantly Th1 type antibody responses while recombinant HBsAg protein vaccines produced in either yeast or CHO cells elicited mostly Th2 type antibody responses. Our data indicate that HBsAg DNA vaccines with improved immunogenicity offer a useful alternative choice to recombinant protein-based HBV vaccines, particularly for therapeutic purposes against chronic hepatitis infection where immune tolerance led to poor antibody responses to S antigens.

  19. Control of tick infestations in cattle vaccinated with bacterial membranes containing surface-exposed tick protective antigens.

    Science.gov (United States)

    Almazán, Consuelo; Moreno-Cantú, Orlando; Moreno-Cid, Juan A; Galindo, Ruth C; Canales, Mario; Villar, Margarita; de la Fuente, José

    2012-01-01

    Vaccines containing the Rhipicephalus (Boophilus) microplus BM86 and BM95 antigens protect cattle against tick infestations. Tick subolesin (SUB), elongation factor 1a (EF1a) and ubiquitin (UBQ) are new candidate protective antigens for the control of cattle tick infestations. Previous studies showed that R. microplus BM95 immunogenic peptides fused to the Anaplasma marginale major surface protein (MSP) 1a N-terminal region (BM95-MSP1a) for presentation on the Escherichia coli membrane were protective against R. microplus infestations in rabbits. In this study, we extended these results by expressing SUB-MSP1a, EF1a-MSP1a and UBQ-MSP1a fusion proteins on the E. coli membrane using this system and demonstrating that bacterial membranes containing the chimeric proteins BM95-MSP1a and SUB-MSP1a were protective (>60% vaccine efficacy) against experimental R. microplus and Rhipicephalus annulatus infestations in cattle. This system provides a novel, simple and cost-effective approach for the production of tick protective antigens by surface display of antigenic protein chimera on the E. coli membrane and demonstrates the possibility of using recombinant bacterial membrane fractions in vaccine preparations to protect cattle against tick infestations. PMID:22085549

  20. Whole tumor antigen vaccination using dendritic cells: Comparison of RNA electroporation and pulsing with UV-irradiated tumor cells

    Directory of Open Access Journals (Sweden)

    Benencia Fabian

    2008-04-01

    Full Text Available Abstract Because of the lack of full characterization of tumor associated antigens for solid tumors, whole antigen use is a convenient approach to tumor vaccination. Tumor RNA and apoptotic tumor cells have been used as a source of whole tumor antigen to prepare dendritic cell (DC based tumor vaccines, but their efficacy has not been directly compared. Here we compare directly RNA electroporation and pulsing of DCs with whole tumor cells killed by ultraviolet (UV B radiation using a convenient tumor model expressing human papilloma virus (HPV E6 and E7 oncogenes. Although both approaches led to DCs presenting tumor antigen, electroporation with tumor cell total RNA induced a significantly higher frequency of tumor-reactive IFN-gamma secreting T cells, and E7-specific CD8+ lymphocytes compared to pulsing with UV-irradiated tumor cells. DCs electroporated with tumor cell RNA induced a larger tumor infiltration by T cells and produced a significantly stronger delay in tumor growth compared to DCs pulsed with UV-irradiated tumor cells. We conclude that electroporation with whole tumor cell RNA and pulsing with UV-irradiated tumor cells are both effective in eliciting antitumor immune response, but RNA electroporation results in more potent tumor vaccination under the examined experimental conditions.

  1. Suppression of humoral immune response to hepatitis B surface antigen vaccine in BALB/c mice by 1-methyl-tryptophan co-administration

    OpenAIRE

    Sparopoulou, T; Eleftheriadis, T; Antoniadi, G; Liakopoulos, V; Stefanidis, I.; Galaktidou, G

    2011-01-01

      Background and the purpose of the study:Indoleamine 2,3-dioxygenase (IDO) suppresses adaptive immune response. The purpose of this study was to determine the effect of the IDO inhibitor namely 1-methyl-DL-tryptophan (DL-1-MT) on antibody production after vaccination with hepatitis B surface (HBs) antigen. Methods:Four groups of BALB/c mice were immunized with a HBs antigen vaccine. In the first group the vaccine had no DL-1-MT, whereas in the other three groups the vaccine containe...

  2. Immunogenicity of three recombinant hepatitis B vaccines administered to students in three doses containing half the antigen amount routinely used for adult vaccination

    Directory of Open Access Journals (Sweden)

    Baldy José Luís da Silveira

    2004-01-01

    Full Text Available We evaluated the immunogenicity of three recombinant hepatitis B vaccines, one Brazilian (Butang, Instituto Butantan and two Korean vaccines (Euvax-B, LG Chemical Ltd. and Hepavax-Gene, Greencross Vaccine Corp., administered intramuscularly to students aged 17 to 19 years in three 10-µg doses (corresponding to half the amount of antigen routinely used for adult vaccination at intervals of one month between the first and second dose, and of four months between the second and third dose. A total of 316 students non-reactive for any serological marker of hepatitis B virus infection were vaccinated: 77 (24.4% with the Butang vaccine, 71 (22.5% with Euvax-B, 85 (26.9% with Hepavax-Gene and, for comparison, 83 (26.2% with Engerix-B (GlaxoSmithKline, whose efficacy in young adults at the dose used here has been confirmed in previous studies. Similar seroconversion rates (anti-HBs > 10 mIU/mL about one month after application of the third dose were obtained for the Butang, Euvax-B, Hepavax-Gene and Engerix-B vaccines (96.2%, 98.6%, 96.5% and 97.6%, respectively. The frequency of good responders (anti-HBs > 100 mIU/mL was also similar among students receiving the four vaccines (85.8%, 91.6%, 89.4% and 89.2%, respectively. The geometric mean titers (GMT of anti-HBs about one month after the third dose obtained with these vaccines were 727.78 ± 6.46 mIU/mL, 2009.09 ± 7.16 mIU/mL, 1729.82 ± 8.85 mIU/mL and 2070.14 ± 11.69 mIU/mL, respectively. The GMT of anti-HBs induced by the Euvax-B and Engerix-B vaccines were higher than those obtained with the Butang vaccine (p < 0.05; this difference was not significant when comparing the other vaccines two-by-two. No spontaneous adverse effects attributable to the application of any dose of the four vaccines were reported.

  3. A Francisella tularensis Live Vaccine Strain That Improves Stimulation of Antigen-Presenting Cells Does Not Enhance Vaccine Efficacy

    OpenAIRE

    Schmitt, Deanna M; Dawn M O'Dee; Joseph Horzempa; Paul E Carlson; Russo, Brian C.; Bales, Jacqueline M.; Brown, Matthew J.; Nau, Gerard J.

    2012-01-01

    Vaccination is a proven strategy to mitigate morbidity and mortality of infectious diseases. The methodology of identifying and testing new vaccine candidates could be improved with rational design and in vitro testing prior to animal experimentation. The tularemia vaccine, Francisella tularensis live vaccine strain (LVS), does not elicit complete protection against lethal challenge with a virulent type A Francisella strain. One factor that may contribute to this poor performance is limited s...

  4. Dengue encephalitis-associated immunopathology in the mouse model: Implications for vaccine developers and antigens inducer of cellular immune response.

    Science.gov (United States)

    Marcos, Ernesto; Lazo, Laura; Gil, Lázaro; Izquierdo, Alienys; Suzarte, Edith; Valdés, Iris; Blanco, Aracelys; Ancizar, Julio; Alba, José Suárez; Pérez, Yusleydis de la C; Cobas, Karen; Romero, Yaremis; Guillén, Gerardo; Guzmán, María G; Hermida, Lisset

    2016-08-01

    Despite the many efforts made by the scientific community in the development of vaccine candidates against dengue virus (DENV), no vaccine has been licensed up to date. Although the immunopathogenesis associated to the disease is a key factor to take into account by vaccine developers, the lack of animal models that reproduce the clinical signs of the disease has hampered the vaccine progress. Non-human primates support viral replication, but they are very expensive and do not show signs of disease. Immunocompromised mice develop viremia and some signs of the disease; however, they are not valuable for vaccine testing. Nowadays, immunocompetent mice are the most used model to evaluate the immunogenicity of vaccine candidates. These animals are resistant to DENV infection; therefore, the intracranial inoculation with neuroadapted virus, which provokes viral encephalitis, represents an alternative to evaluate the protective capacity of vaccine candidates. Previous results have demonstrated the crucial role of cellular immune response in the protection induced by the virus and vaccine candidates in this mouse encephalitis model. However, in the present work we are proposing that the magnitude of the cell-mediated immunity and the inflammatory response generated by the vaccine can modulate the survival rate after viral challenge. We observed that the intracranial challenge of naïve mice with DENV-2 induces the recruitment of immune cells that contribute to the reduction of viral load, but does not increase the survival rate. On the contrary, animals treated with cyclophosphamide, an immunosuppressive drug that affects proliferating lymphocytes, had a higher viral load but a better survival rate than untreated animals. These results suggest that the immune system is playing an immunopathogenic role in this model and the survival rate may not be a suitable endpoint in the evaluation of vaccine candidates based on antigens that induce a strong cellular immune response

  5. Hepatitis B Vaccination Coverage and Prevalence of Hepatitis B Surface Antigen Among Children in French Polynesia, 2014.

    Science.gov (United States)

    Patel, Minal K; Le Calvez, Evelyne; Wannemuehler, Kathleen; Ségalin, Jean-Marc

    2016-06-01

    French Polynesia is considered to be moderately endemic for chronic hepatitis B virus infection, with an estimated 3% of the population having hepatitis B surface antigen (HBsAg). From 1990 to 1992, a 3-dose hepatitis B vaccination series was introduced into the routine infant immunization schedule in French Polynesia, including a birth dose (BD). In 2014, a nationally representative 2-stage cluster survey was undertaken to evaluate the impact of the vaccination program on HBsAg prevalence among school children (∼6 years of age) in Cours Préparatoire (CP). Documented vaccination data were reviewed for all eligible children; children with consent were tested for HBsAg with a rapid point-of-care test. In total, 1,660 students were identified; 1,567 (94%) had vaccination data for review and 1,196 (72%) participated in the serosurvey. Three-dose vaccination coverage was 98%, while timely BD coverage, defined as a dose administered within 24 hours of life, was 89%. Receipt of the second and third doses was often delayed, with 75% and 55% receiving a second and third dose within 1 month of the recommended age, respectively. No children tested positive for HBsAg. French Polynesia's vaccination program has achieved high coverage and an HBsAg seroprevalence of 0% (0-0.5%) among CP school children, but timeliness of vaccination could be improved. PMID:27001757

  6. Induction of antigen-specific immunity by pH-sensitive carbonate apatite as a potent vaccine carrier

    Energy Technology Data Exchange (ETDEWEB)

    Hebishima, Takehisa [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tada, Seiichi [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Takeshima, Shin-nosuke [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Akaike, Toshihiro [Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501 (Japan); Ito, Yoshihiro [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Aida, Yoko, E-mail: aida@riken.jp [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2011-12-02

    Highlights: Black-Right-Pointing-Pointer To develop effective vaccine, we examined the effects of CO{sub 3}Ap as an antigen carrier. Black-Right-Pointing-Pointer OVA contained in CO{sub 3}Ap was taken up by BMDCs more effectively than free OVA. Black-Right-Pointing-Pointer OVA-immunized splenocytes was activated by OVA contained in CO{sub 3}Ap effectively. Black-Right-Pointing-Pointer OVA contained in CO{sub 3}Ap induced strong OVA-specific immune responses to C57BL/6 mice. Black-Right-Pointing-Pointer CO{sub 3}Ap is promising antigen carrier for the achievement of effective vaccine. -- Abstract: The ability of carbonate apatite (CO{sub 3}Ap) to enhance antigen-specific immunity was examined in vitro and in vivo to investigate its utility as a vaccine carrier. Murine bone marrow-derived dendritic cells took up ovalbumin (OVA) containing CO{sub 3}Ap more effectively than free OVA. Interestingly, mice immunized with OVA-containing CO{sub 3}Ap produced OVA-specific antibodies more effectively than mice immunized with free OVA. Furthermore, immunization of C57BL/6 mice with OVA-containing CO{sub 3}Ap induced the proliferation and antigen-specific production of IFN-{gamma} by splenocytes more strongly than immunization with free OVA. Moreover, no significant differences were detected in the induction of delayed-type hypersensitivity responses, an immune reaction involving an antigen-specific, cell-mediated immune response between OVA-containing CO{sub 3}Ap and OVA-containing alumina salt (Alum), suggesting that CO{sub 3}Ap induced cell-mediated immune response to the same degree as Alum, which is commonly used for clinical applications. This study is the first to demonstrate the induction of antigen-specific immune responses in vivo by CO{sub 3}Ap.

  7. Induction of antigen-specific immunity by pH-sensitive carbonate apatite as a potent vaccine carrier

    International Nuclear Information System (INIS)

    Highlights: ► To develop effective vaccine, we examined the effects of CO3Ap as an antigen carrier. ► OVA contained in CO3Ap was taken up by BMDCs more effectively than free OVA. ► OVA-immunized splenocytes was activated by OVA contained in CO3Ap effectively. ► OVA contained in CO3Ap induced strong OVA-specific immune responses to C57BL/6 mice. ► CO3Ap is promising antigen carrier for the achievement of effective vaccine. -- Abstract: The ability of carbonate apatite (CO3Ap) to enhance antigen-specific immunity was examined in vitro and in vivo to investigate its utility as a vaccine carrier. Murine bone marrow-derived dendritic cells took up ovalbumin (OVA) containing CO3Ap more effectively than free OVA. Interestingly, mice immunized with OVA-containing CO3Ap produced OVA-specific antibodies more effectively than mice immunized with free OVA. Furthermore, immunization of C57BL/6 mice with OVA-containing CO3Ap induced the proliferation and antigen-specific production of IFN-γ by splenocytes more strongly than immunization with free OVA. Moreover, no significant differences were detected in the induction of delayed-type hypersensitivity responses, an immune reaction involving an antigen-specific, cell-mediated immune response between OVA-containing CO3Ap and OVA-containing alumina salt (Alum), suggesting that CO3Ap induced cell-mediated immune response to the same degree as Alum, which is commonly used for clinical applications. This study is the first to demonstrate the induction of antigen-specific immune responses in vivo by CO3Ap.

  8. Immune responses induced by a Leishmania (Leishmania) amazonensis recombinant antigen in mice and lymphocytes from vaccinated subjects

    OpenAIRE

    Fernandes, Ana Paula; Elizabeth Cortez HERRERA; Wilson MAYRINK; Gazzinelli, Ricardo T.; LIU Wen Yu; Carlos Alberto da COSTA; Tavares, Carlos Alberto Pereira; Melo, Maria Norma; Michalick, Marilene Susan Marques; Gentz, Reiner; NASCIMENTO Evaldo

    1997-01-01

    In the search for Leishmania recombinant antigens that can be used as a vaccine against American Cutaneous Leishmaniasis, we identified a Leishmania (Leishmania) amazonensis recombinant protein of 33 kD (Larp33) which is recognized by antibodies and peripheral blood leukocytes (PBL) from subjects vaccinated with Leishvacin ®, Larp33 was expressed in Escherichia coli after cloning of a 2,2 kb Sau3A digested genomic fragment of L. (L.) amazonensis into the pDS56-6 His vector. Immunoblotting ana...

  9. A computational method for identification of vaccine targets from protein regions of conserved human leukocyte antigen binding

    DEFF Research Database (Denmark)

    Olsen, Lars Rønn; Simon, Christian; Kudahl, Ulrich J.;

    2015-01-01

    variable regions, where all variants bind HLA. These regions, although variable, can thus be considered stable in terms of HLA binding and represent valuable vaccine targets. Results: We applied this method to predict CD8+ T-cell targets in influenza A H7N9 hemagglutinin and significantly increased the...... number of potential vaccine targets compared to the number of targets discovered using the traditional approach where low-frequency peptides are excluded. Conclusions: We developed a webserver with an intuitive visualization scheme for summarizing the T cell-based antigenic potential of any given protein...

  10. Safety and immunogenicity of multi-antigen AMA1-based vaccines formulated with CoVaccine HT™ and Montanide ISA 51 in rhesus macaques

    Directory of Open Access Journals (Sweden)

    Walraven Vanessa

    2011-07-01

    Full Text Available Abstract Background Increasing the breadth of the functional antibody response through immunization with Plasmodium falciparum apical membrane antigen 1 (PfAMA1 multi-allele vaccine formulations has been demonstrated in several rodent and rabbit studies. This study assesses the safety and immunogenicity of three PfAMA1 Diversity-Covering (DiCo vaccine candidates formulated as an equimolar mixture (DiCo mix in CoVaccine HT™ or Montanide ISA 51, as well as that of a PfAMA1-MSP119 fusion protein formulated in Montanide ISA 51. Methods Vaccine safety in rhesus macaques was monitored by animal behaviour observation and assessment of organ and systemic functions through clinical chemistry and haematology measurements. The immunogenicity of vaccine formulations was assessed by enzyme-linked immunosorbent assays and in vitro parasite growth inhibition assays with three culture-adapted P. falciparum strains. Results These data show that both adjuvants were well tolerated with only transient changes in a few of the chemical and haematological parameters measured. DiCo mix formulated in CoVaccine HT™ proved immunologically and functionally superior to the same candidate formulated in Montanide ISA 51. Immunological data from the fusion protein candidate was however difficult to interpret as four out of six immunized animals were non-responsive for unknown reasons. Conclusions The study highlights the safety and immunological benefits of DiCo mix as a potential human vaccine against blood stage malaria, especially when formulated in CoVaccine HT™, and adds to the accumulating data on the specificity broadening effects of DiCo mix.

  11. Bm86 antigen induces a protective immune response against Boophilus microplus following DNA and protein vaccination in sheep.

    Science.gov (United States)

    De Rose, R; McKenna, R V; Cobon, G; Tennent, J; Zakrzewski, H; Gale, K; Wood, P R; Scheerlinck, J P; Willadsen, P

    1999-11-30

    Vaccination of sheep with a plasmid bearing the full length gene for the tick antigen Bm86 either alone or co-administered with plasmid carrying the ovine genes for the cytokines, granulocyte and macrophage colony stimulating factor (GM-CSF) or interleukin (IL)-1beta induced a relatively low level of protection against subsequent tick infestation. This tick damage reached statistical significance only for the groups which were vaccinated with plasmid encoding for Bm86, co-administered with plasmid encoding for ovine GM-CSF. Antibody titres measured against Bm86 were also low in all groups injected with the Bm86 DNA vaccine. Antibody production and anti-tick effect were significantly less than that achieved by two vaccinations with recombinant Bm86 protein. In all cases only a low level of antigen-specific stimulation of peripheral blood lymphocytes was recorded, as measured either by the incorporation of tritiated thymidine or the release of IFN-gamma. Injection of DNA encoding for Bm86, either alone or with co-administered cytokine genes, did however prime for a strong subsequent antibody response following a single injection of recombinant Bm86 protein in adjuvant. Antibody production nevertheless appeared to be slightly less effective than following two vaccinations with recombinant protein. The persistence of antibody following vaccination was the same regardless of the method of primary sensitization. In all cases the half-life of the antibody response was approximately 40-50 days indicating that, in contrast to results reported in mice, DNA vaccination in sheep did not result in sustained antibody production. PMID:10587297

  12. Bottlenose dolphin (Tursiops truncatus) papillomaviruses: vaccine antigen candidates and screening test development.

    Science.gov (United States)

    Rehtanz, Manuela; Bossart, Gregory D; Doescher, Bethany; Rector, Annabel; Van Ranst, Marc; Fair, Patricia A; Jenson, Alfred B; Ghim, Shin-Je

    2009-01-01

    Papillomaviruses (PVs) have been shown as being the etiologic agents of various benign and malignant tumours in many vertebrate species. In dolphins and porpoises, a high prevalence of orogenital tumours has recently been documented with at least four distinct novel species-specific PV types detected in such lesions. Therefore, we generated the immunological reagents to establish a serological screening test to determine the prevalence of PV infection in Atlantic bottlenose dolphins [(Tursiops truncatus (Tt)]. Using the baculovirus expression system, virus-like particles (VLPs) derived from the L1 proteins of two TtPV types, TtPV1 and TtPV2, were generated. Polyclonal antibodies against TtPV VLPs were produced in rabbits and their specificity for the VLPs was confirmed. Electron microscopy and enzyme-linked immunosorbent assay (ELISA) studies revealed that the generated VLPs self-assembled into particles presenting conformational immunodominant epitopes. As such, these particles are potential antigen candidates for a TtPV vaccine. Subsequently, the VLPs served as antigens in initial ELISA tests using sera from six bottlenose dolphins to investigate PV antibody presence. Three of these sera were derived from dolphins with genital tumour history and showed positive PV ELISA reactivity, while the remaining sera from lesion-free dolphins were PV antibody-negative. The results suggest that the developed screening test may serve as a potential tool for determining PV prevalence and thus for observing transmission rates in dolphin populations as the significance of PV infection in cetaceans starts to unfold. PMID:18676105

  13. Protection Afforded by a Recombinant Turkey Herpesvirus-H5 Vaccine Against the 2014 European Highly Pathogenic H5N8 Avian Influenza Strain.

    Science.gov (United States)

    Steensels, M; Rauw, F; van den Berg, Th; Marché, S; Gardin, Y; Palya, V; Lambrecht, B

    2016-05-01

    A highly pathogenic avian influenza (HPAI) H5N8 (clade 2.3.4.4) virus, circulating in Asia (South Korea, Japan, and southern China) since the beginning of 2014, reached the European continent in November 2014. Germany, the Netherlands, the United Kingdom, Italy, and Hungary confirmed H5N8 infection of poultry farms of different species and of several wild bird species. Unlike the Asian highly pathogenic (HP) H5N1, this HP H5N8 also went transatlantic and reached the American West Coast by the end of 2014, affecting wild birds as well as backyard and commercial poultry. This strain induces high mortality and morbidity in Galliformes, whereas wild birds seem only moderately affected. A recombinant turkey herpesvirus (rHVT) vector vaccine expressing the H5 gene of a clade 2.2 H5N1 strain (rHVT-H5) previously demonstrated a highly efficient clinical protection and reduced viral excretion against challenge with Asian HP H5N1 strains of various clades (2.2, 2.2.1, 2.2.1.1, 2.1.3, 2.1.3.2, and 2.3.2.1) and was made commercially available in various countries where the disease is endemic. To evaluate the protective efficacy of the rHVT-H5 vaccine against the first German H5N8 turkey isolate (H5N8 GE), a challenge experiment was set up in specific-pathogen-free (SPF) chickens, and the clinical and excretional protection was evaluated. SPF chickens were vaccinated subcutaneously at 1 day old and challenged oculonasally at 4 wk of age with two viral dosages, 10(5) and 10(6) 50% egg infective doses. Morbidity and mortality were monitored daily in unvaccinated and vaccinated groups, whereas viral shedding by oropharyngeal and cloacal routes was evaluated at 2, 5, 9, and 14 days postinoculation (dpi). Serologic monitoring after vaccination and challenge was also carried out. Despite its high antigenic divergence of the challenge H5N8 strain, a single rHVT-H5 vaccine administration at 1 day old resulted in a full clinical protection against challenge and a significant reduction

  14. H3N2 Mismatch of 2014-15 Northern Hemisphere Influenza Vaccines and Head-to-head Comparison between Human and Ferret Antisera derived Antigenic Maps

    Science.gov (United States)

    Xie, Hang; Wan, Xiu-Feng; Ye, Zhiping; Plant, Ewan P.; Zhao, Yangqing; Xu, Yifei; Li, Xing; Finch, Courtney; Zhao, Nan; Kawano, Toshiaki; Zoueva, Olga; Chiang, Meng-Jung; Jing, Xianghong; Lin, Zhengshi; Zhang, Anding; Zhu, Yanhong

    2015-10-01

    The poor performance of 2014-15 Northern Hemisphere (NH) influenza vaccines was attributed to mismatched H3N2 component with circulating epidemic strains. Using human serum samples collected from 2009-10, 2010-11 and 2014-15 NH influenza vaccine trials, we assessed their cross-reactive hemagglutination inhibition (HAI) antibody responses against recent H3 epidemic isolates. All three populations (children, adults, and older adults) vaccinated with the 2014-15 NH egg- or cell-based vaccine, showed >50% reduction in HAI post-vaccination geometric mean titers against epidemic H3 isolates from those against egg-grown H3 vaccine strain A/Texas/50/2012 (TX/12e). The 2014-15 NH vaccines, regardless of production type, failed to further extend HAI cross-reactivity against H3 epidemic strains from previous seasonal vaccines. Head-to-head comparison between ferret and human antisera derived antigenic maps revealed different antigenic patterns among representative egg- and cell-grown H3 viruses characterized. Molecular modeling indicated that the mutations of epidemic H3 strains were mainly located in antibody-binding sites A and B as compared with TX/12e. To improve vaccine strain selection, human serologic testing on vaccination-induced cross-reactivity need be emphasized along with virus antigenic characterization by ferret model.

  15. In vivo persistence and protective efficacy of the bacille Calmette Guerin vaccine overexpressing the HspX latency antigen

    OpenAIRE

    Spratt, Joanne M.; Britton, Warwick J; Triccas, James A.

    2010-01-01

    New strategies to control infection with Mycobacterium tuberculosis, the causative agent of tuberculosis, are urgently required, particularly in areas where acquired immunodeficiencies are prevalent. In this report we have determined if modification of the current tuberculosis vaccine, Mycobacterium bovis BCG, to constitutively express the mycobacterial HspX latency antigen altered its protective effect against challenge with virulent M. tuberculosis. Overexpression of M. tuberculosis HspX in...

  16. Establishment of an in vivo potency assay for the recombinant hepatit is B surface antigen in monovalent and combined vaccines

    OpenAIRE

    Mabel Izquierdo-López; Karelia Cosme-Diaz; Gerardo García-Illera; Zoe Núñez-Lamotte; Yamila Martínez- Cuéllar; Maribel Vega-Simón; Lourdes Costa-Anguiano; Marisel Quintana-Esquivel; Ileana Rosales-Torres; Omar Mosqueda-Lobaina

    2014-01-01

    In this paper the development of potency assay in animals (mice) was made, with the objective of demonstrating the immunogenic power of the recombinant Hepatitis B surface antigen in monovalent and combined vaccines, produced at the Center of Genetic Engineering and Biotechnology. The potency test is a parameter in quality control and it is also a tool to demonstrate the consistency of the production process. Parameters such as duration of the test, number of animals in the test, ...

  17. Geminiviral vectors based on bean yellow dwarf virus for production of vaccine antigens and monoclonal antibodies in plants

    OpenAIRE

    Chen, Qiang; He, Junyun; Phoolcharoen, Waranyoo; Mason, Hugh S.

    2011-01-01

    Expression of recombinant vaccine antigens and monoclonal antibodies using plant viral vectors has developed extensively during the past several years. The approach benefits from high yields of recombinant protein obtained within days after transient delivery of viral vectors to leaves of Nicotiana benthamiana, a tobacco relative. Modified viral genomes of both RNA and DNA viruses have been created. Geminiviruses such as bean yellow dwarf virus (BeYDV) have a small, single stranded DNA genome...

  18. Immunogenicity and protective efficacy of recombinant Modified Vaccinia virus Ankara candidate vaccines delivering West Nile virus envelope antigens.

    Science.gov (United States)

    Volz, Asisa; Lim, Stephanie; Kaserer, Martina; Lülf, Anna; Marr, Lisa; Jany, Sylvia; Deeg, Cornelia A; Pijlman, Gorben P; Koraka, Penelope; Osterhaus, Albert D M E; Martina, Byron E; Sutter, Gerd

    2016-04-01

    West Nile virus (WNV) cycles between insects and wild birds, and is transmitted via mosquito vectors to horses and humans, potentially causing severe neuroinvasive disease. Modified Vaccinia virus Ankara (MVA) is an advanced viral vector for developing new recombinant vaccines against infectious diseases and cancer. Here, we generated and evaluated recombinant MVA candidate vaccines that deliver WNV envelope (E) antigens and fulfil all the requirements to proceed to clinical testing in humans. Infections of human and equine cell cultures with recombinant MVA demonstrated efficient synthesis and secretion of WNV envelope proteins in mammalian cells non-permissive for MVA replication. Prime-boost immunizations in BALB/c mice readily induced circulating serum antibodies binding to recombinant WNV E protein and neutralizing WNV in tissue culture infections. Vaccinations in HLA-A2.1-/HLA-DR1-transgenic H-2 class I-/class II-knockout mice elicited WNV E-specific CD8+ T cell responses. Moreover, the MVA-WNV candidate vaccines protected C57BL/6 mice against lineage 1 and lineage 2 WNV infection and induced heterologous neutralizing antibodies. Thus, further studies are warranted to evaluate these recombinant MVA-WNV vaccines in other preclinical models and use them as candidate vaccine in humans. PMID:26939903

  19. A dual TLR agonist adjuvant enhances the immunogenicity and protective efficacy of the tuberculosis vaccine antigen ID93.

    Directory of Open Access Journals (Sweden)

    Mark T Orr

    Full Text Available With over eight million cases of tuberculosis each year there is a pressing need for the development of new vaccines against Mycobacterium tuberculosis. Subunit vaccines consisting of recombinant proteins are an attractive vaccine approach due to their inherent safety compared to attenuated live vaccines and the uniformity of manufacture. Addition of properly formulated TLR agonist-containing adjuvants to recombinant protein vaccines enhances the antigen-specific CD4(+ T cell response characterized by IFN-γ and TNF, both of which are critical for the control of TB. We have developed a clinical stage vaccine candidate consisting of a recombinant fusion protein ID93 adjuvanted with the TLR4 agonist GLA-SE. Here we examine whether ID93+GLA-SE can be improved by the addition of a second TLR agonist. Addition of CpG containing DNA to ID93+GLA-SE enhanced the magnitude of the multi-functional TH1 response against ID93 characterized by co-production of IFN-γ, TNF, and IL-2. Addition of CpG also improved the protective efficacy of ID93+GLA-SE. Finally we demonstrate that this adjuvant synergy between GLA and CpG is independent of TRIF signaling, whereas TRIF is necessary for the adjuvant activity of GLA-SE in the absence of CpG.

  20. Development of a live attenuated antigenic marker classical swine fever vaccine

    Science.gov (United States)

    Classical Swine Fever, caused by Classical Swine Fever Virus (CSFV), is a highly contagious disease affecting swine worldwide. The two main strategies for disease control are prophylactic vaccination and non-vaccination “stamping out” policies. In a vaccination-to-live strategy, marker vaccines coul...

  1. Presenting a foreign antigen on live attenuated Edwardsiella tarda using twin-arginine translocation signal peptide as a multivalent vaccine.

    Science.gov (United States)

    Wang, Yamin; Yang, Weizheng; Wang, Qiyao; Qu, Jiangbo; Zhang, Yuanxing

    2013-12-01

    The twin-arginine translocation (Tat) system is a major pathway for transmembrane translocation of fully folded proteins. In this study, a multivalent vaccine to present foreign antigens on live attenuated vaccine Edwardsiella tarda WED using screened Tat signal peptide was constructed. Because the Tat system increases the yields of folded antigens in periplasmic space or extracellular milieu, it is expected to contribute to the production of conformational epitope-derived specific antibodies. E. tarda Tat signal peptides fused with the green fluorescent protein (GFP) was constructed under the control of an in vivo inducible dps promoter. The resulting plasmids were electroporated into WED and the subcellular localizations of GFP were analyzed with Western blotting. Eight signal peptides with optimized GFP translocation efficiency were further fused to a protective antigen glyceraldehyde-3-phosphate dehydrogenase (GapA) from a fish pathogen Aeromonas hydrophila. Signal peptides of DmsA, NapA, and SufI displayed high efficiency for GapA translocation. The relative percent survival (RPS) of turbot was measured with a co-infection of E. tarda and A. hydrophila, and the strain with DmsA signal peptide showed the maximal protection. This study demonstrated a new platform to construct multivalent vaccines using optimized Tat signal peptide in E. tarda. PMID:23994481

  2. Prime-boost bacillus Calmette-Guérin vaccination with lentivirus-vectored and DNA-based vaccines expressing antigens Ag85B and Rv3425 improves protective efficacy against Mycobacterium tuberculosis in mice.

    Science.gov (United States)

    Xu, Ying; Yang, Enzhuo; Wang, Jianguang; Li, Rui; Li, Guanghua; Liu, Guoyuan; Song, Na; Huang, Qi; Kong, Cong; Wang, Honghai

    2014-10-01

    To prevent the global spread of tuberculosis (TB), more effective vaccines and vaccination strategies are urgently needed. As a result of the success of bacillus Calmette-Guérin (BCG) in protecting children against miliary and meningeal TB, the majority of individuals will have been vaccinated with BCG; hence, boosting BCG-primed immunity will probably be a key component of future vaccine strategies. In this study, we compared the ability of DNA-, protein- and lentiviral vector-based vaccines that express the antigens Ag85B and Rv3425 to boost the effects of BCG in the context of immunity and protection against Mycobacterium tuberculosis in C57BL/6 mice. Our results demonstrated that prime-boost BCG vaccination with a lentiviral vector expressing the antigens Ag85B and Rv3425 significantly enhanced immune responses, including T helper type 1 and CD8(+) cytotoxic T lymphocyte responses, compared with DNA- and protein-based vaccines. However, lentivirus-vectored and DNA-based vaccines greatly improved the protective efficacy of BCG against M. tuberculosis, as indicated by a lack of weight loss and significantly reduced bacterial loads and histological damage in the lung. Our study suggests that the use of lentiviral or DNA vaccines containing the antigens Ag85B and Rv3425 to boost BCG is a good choice for the rational design of an efficient vaccination strategy against TB. PMID:24773322

  3. Increasing a Robust Antigen-Specific Cytotoxic T Lymphocyte Response by FMDV DNA Vaccination with IL-9 Expressing Construct

    Directory of Open Access Journals (Sweden)

    Qiang Zou

    2010-01-01

    Full Text Available Various chemokines and cytokines as adjuvants can be used to improve efficacy of DNA vaccination. In this study, we sought to investigate if a DNA construct expressing IL-9 (designed as proV-IL9 as a molecular adjuvant enhance antigen specific immune responses elicited by the pcD-VP1 DNA vaccination. Mice immunized with pcD-VP1 combined with proV-IL9 developed a strong humoral response. In addition, the coinoculation induced significant higher level of antigen-specific cell proliferation and cytotoxic response. This agreed well with higher expression level of IFN-γ and perforin in CD8+ T cells, but not with IL-17 in these T cells. The results indicate that IL-9 induces the development of IFN-γ-producing CD8+ T cells (Tc1, but not the IL-17-producing CD8+ T cells (Tc17. Up-regulated expressions of BCL-2 and BCL-XL were exhibited in these Tc1 cells, suggesting that IL-9 may trigger antiapoptosis mechanism in these cells. Together, these results demonstrated that IL-9 used as molecular adjuvant could enhance the immunogenicity of DNA vaccination, in augmenting humoral and cellular responses and particularly promoting Tc1 activations. Thus, the IL-9 may be utilized as a potent Tc1 adjuvant for DNA vaccines.

  4. Sequence variations in the Boophilus microplus Bm86 locus and implications for immunoprotection in cattle vaccinated with this antigen.

    Science.gov (United States)

    García-García, J C; Gonzalez, I L; González, D M; Valdés, M; Méndez, L; Lamberti, J; D'Agostino, B; Citroni, D; Fragoso, H; Ortiz, M; Rodríguez, M; de la Fuente, J

    1999-11-01

    Cattle tick infestations constitute a major problem for the cattle industry in tropical and subtropical regions of the world. Traditional control methods have been only partially successful, hampered by the selection of chemical-resistant tick populations. The Boophilus microplus Bm86 protein was isolated from tick gut epithelial cells and shown to induce a protective response against tick infestations in vaccinated cattle. Vaccine preparations including the recombinant Bm86 are used to control cattle tick infestations in the field as an alternative measure to reduce the losses produced by this ectoparasite. The principle for the immunological control of tick infestations relies on a polyclonal antibody response against the target antigen and, therefore, should be difficult to select for tick-resistant populations. However, sequence variations in the Bm86 locus, among other factors, could affect the effectiveness of Bm86-containing vaccines. In the present study we have addressed this issue, employing data obtained with B. microplus strains from Australia, Mexico, Cuba, Argentina and Venezuela. The results showed a tendency in the inverse correlation between the efficacy of the vaccination with Bm86 and the sequence variations in the Bm86 locus (R2 = 0.7). The mutation fixation index in the Bm86 locus was calculated and shown to be between 0.02 and 0.1 amino acids per year. Possible implications of these findings for the immunoprotection of cattle against tick infestations employing the Bm86 antigen are discussed. PMID:10668863

  5. Vaccination trials in sheep against Chrysomya bezziana larvae using the recombinant peritrophin antigens Cb15, Cb42 and Cb48

    Directory of Open Access Journals (Sweden)

    Sukarsih

    2000-10-01

    Full Text Available Recombinant forms of a number of peritrophic membrane proteins from the screwworm fly Chrysomya bezziana have been assessed in vitro and in vivo for their efficacy as antigens in vaccination against the tissue-invasive, larval form of the parasite. The proteins included Cb15 and Cb42 expressed in Escherichia coli and Cb48 expressed in both Escherichia coli and Pichia pastoris. In all cases, the in vitro assays of larval growth on serum from vaccinated sheep failed to show inhibition of larval weight gain or any detrimental effect on larval survival relative to controls. Chrysomya bezziana Cb48 has a significant degree of sequence identity with the antigen PM48 from Lucilia cuprina. Feeding Lucilia cuprina larvae on antisera to Cb48 induced a small but statistically significant reduction in weight gain, as does feeding on antisera to PM48. In vivo, larvae feeding on sheep vaccinated with Escherichia coli-expressed Cb15 and Cb42 and Pichia pastoris-expressed Cb48 showed marginally greater weight gain and survival which was equal to or greater than that on non-vaccinated sheep. The significance of these observations is discussed.

  6. Phase I Study of Safety and Immunogenicity of an Escherichia coli-Derived Recombinant Protective Antigen (rPA) Vaccine to Prevent Anthrax in Adults

    OpenAIRE

    Brown, Bruce K.; Josephine Cox; Anita Gillis; VanCott, Thomas C.; Mary Marovich; Mark Milazzo; Tanya Santelli Antonille; Lindsay Wieczorek; Mckee, Kelly T.; Karen Metcalfe; Mallory, Raburn M.; Deborah Birx; Polonis, Victoria R.; Merlin L Robb

    2010-01-01

    BACKGROUND: The fatal disease caused by Bacillus anthracis is preventable with a prophylactic vaccine. The currently available anthrax vaccine requires a lengthy immunization schedule, and simpler and more immunogenic options for protection against anthrax are a priority for development. In this report we describe a phase I clinical trial testing the safety and immunogenicity of an anthrax vaccine using recombinant Escherichia coli-derived, B. anthracis protective antigen (rPA). METHODOLOGY/P...

  7. Antigen Processing of the Heptavalent Pneumococcal Conjugate Vaccine Carrier Protein CRM197 Differs Depending on the Serotype of the Attached Polysaccharide

    OpenAIRE

    Leonard, Ethan G.; Canaday, David H.; Harding, Clifford V.; Schreiber, John R.

    2003-01-01

    The pneumococcal (Pn) conjugate vaccine includes seven different polysaccharides (PS) conjugated to CRM197. Utilizing antigen-processing cells and a CRM197-specific mouse T-cell hybridoma, we found that the serotype of conjugated PnPS dramatically affected antigen processing of CRM197. Unconjugated CRM197 and serotype conjugates 14 and 18C were processed more efficiently.

  8. Comparative testing of six antigen-based malaria vaccine candidates directed toward merozoite-stage Plasmodium falciparum

    DEFF Research Database (Denmark)

    Arnot, David E; Cavanagh, David R; Remarque, Edmond J;

    2008-01-01

    Immunogenicity testing of Plasmodium falciparum antigens being considered as malaria vaccine candidates was undertaken in rabbits. The antigens compared were recombinant baculovirus MSP-1(19) and five Pichia pastoris candidates, including two versions of MSP-1(19), AMA-1 (domains I and II), AMA-1...

  9. A New Gene Family (ariel) Encodes Asparagine-Rich Entamoeba histolytica Antigens, Which Resemble the Amebic Vaccine Candidate Serine-Rich E. histolytica Protein

    OpenAIRE

    Mai, Zhiming; Samuelson, John

    1998-01-01

    A family of genes, called ariel, are named for and encode asparagine-rich Entamoeba histolytica antigens containing 2 to 16 octapeptide repeats. Ariel proteins, which are constitutively expressed by trophozoites, belong to a large antigen family that includes the serine-rich E. histolytica protein (SREHP), an amebic vaccine candidate.

  10. Suppression of humoral immune response to hepatitis B surface antigen vaccine in BALB/c mice by 1-methyl-tryptophan co-administration

    Directory of Open Access Journals (Sweden)

    T Sparopoulou

    2011-07-01

    Full Text Available   Background and the purpose of the study:Indoleamine 2,3-dioxygenase (IDO suppresses adaptive immune response. The purpose of this study was to determine the effect of the IDO inhibitor namely 1-methyl-DL-tryptophan (DL-1-MT on antibody production after vaccination with hepatitis B surface (HBs antigen. Methods:Four groups of BALB/c mice were immunized with a HBs antigen vaccine. In the first group the vaccine had no DL-1-MT, whereas in the other three groups the vaccine contained 1 mg , 10 mg and 20 mg DL-1-MT. Blood samples were collected 5 weeks post-vaccination and anti-HBs antibodies in the serum were measured by ELISA. Results:Compared to the three groups of mice that were immunized with the vaccines containing DL-1-MT, serum anti-HBs level was much higher in the mice that were immunized with the vaccine with out DL-1-MT. Conclusions:Inhibition of IDO at the time of vaccination decreased humoral immune response to HBs antigen vaccine. The idea that IDO activity is simply immunosuppressive may need to be re-evaluated.

  11. Evaluation of a Salmonella vectored vaccine expressing Mycobacterium avium subsp. paratuberculosis antigens against challenge in a goat model.

    Directory of Open Access Journals (Sweden)

    Syed M Faisal

    Full Text Available Johnes disease (JD, caused by Mycobacterium avium subsp paratuberculosis (MAP, occurs worldwide as chronic granulomatous enteritis of domestic and wild ruminants. To develop a cost effective vaccine, in a previous study we constructed an attenuated Salmonella strain that expressed a fusion product made up of partial fragments of MAP antigens (Ag85A, Ag85B and SOD that imparted protection against challenge in a mouse model. In the current study we evaluated the differential immune response and protective efficacy of the Sal-Ag vaccine against challenge in a goat model as compared to the live attenuated vaccine MAP316F. PBMCs from goats vaccinated with Sal-Ag and challenged with MAP generated significantly lower levels of IFN-γ, following in vitro stimulation with either Antigen-mix or PPD jhonin, than PBMC from MAP316F vaccinated animals. Flow cytometric analysis showed the increase in IFN-γ correlated with a significantly higher level of proliferation of CD4, CD8 and γδT cells and an increased expression of CD25 and CD45R0 in MAP316F vaccinated animals as compared to control animals. Evaluation of a range of cytokines involved in Th1, Th2, Treg, and Th17 immune responses by quantitative PCR showed low levels of expression of Th1 (IFN-γ, IL-2, IL-12 and proinflammatory cytokines (IL-6, IL-8, IL-18, TNF-α in the Sal-Ag immunized group. Significant levels of Th2 and anti-inflammatory cytokines transcripts (IL-4, IL-10, IL-13, TGF-β were expressed but their level was low and with a pattern similar to the control group. Over all, Sal-Ag vaccine imparted partial protection that limited colonization in tissues of some animals upon challenge with wild type MAP but not to the level achieved with MAP316F. In conclusion, the data indicates that Sal-Ag vaccine induced only a low level of protective immunity that failed to limit the colonization of MAP in infected animals. Hence the Sal-Ag vaccine needs further refinement to increase its efficacy.

  12. Towards a universal vaccine for avian influenza: protective efficacy of modified Vaccinia virus Ankara and Adenovirus vaccines expressing conserved influenza antigens in chickens challenged with low pathogenic avian influenza virus.

    Science.gov (United States)

    Boyd, Amy C; Ruiz-Hernandez, Raul; Peroval, Marylene Y; Carson, Connor; Balkissoon, Devanand; Staines, Karen; Turner, Alison V; Hill, Adrian V S; Gilbert, Sarah C; Butter, Colin

    2013-01-11

    Current vaccines targeting surface proteins can drive antigenic variation resulting either in the emergence of more highly pathogenic viruses or of antigenically distinct viruses that escape control by vaccination and thereby persist in the host population. Influenza vaccines typically target the highly mutable surface proteins and do not provide protection against heterologous challenge. Vaccines which induce immune responses against conserved influenza epitopes may confer protection against heterologous challenge. We report here the results of vaccination with recombinant modified Vaccinia virus Ankara (MVA) and Adenovirus (Ad) expressing a fusion construct of nucleoprotein and matrix protein (NP+M1). Prime and boost vaccination regimes were trialled in different ages of chicken and were found to be safe and immunogenic. Interferon-γ (IFN-γ) ELISpot was used to assess the cellular immune response post secondary vaccination. In ovo Ad prime followed by a 4 week post hatch MVA boost was identified as the most immunogenic regime in one outbred and two inbred lines of chicken. Following vaccination, one inbred line (C15I) was challenged with low pathogenic avian influenza (LPAI) H7N7 (A/Turkey/England/1977). Birds receiving a primary vaccination with Ad-NP+M1 and a secondary vaccination with MVA-NP+M1 exhibited reduced cloacal shedding as measured by plaque assay at 7 days post infection compared with birds vaccinated with recombinant viruses containing irrelevant antigen. This preliminary indication of efficacy demonstrates proof of concept in birds; induction of T cell responses in chickens by viral vectors containing internal influenza antigens may be a productive strategy for the development of vaccines to induce heterologous protection against influenza in poultry. PMID:23200938

  13. Optimization of immune responses induced by therapeutic vaccination with cross-reactive antigens in a humanized hepatitis B surface antigen transgenic mouse model.

    Science.gov (United States)

    Bourgine, Maryline; Dion, Sarah; Godon, Ophélie; Guillen, Gerardo; Michel, Marie-Louise; Aguilar, Julio Cesar

    2012-08-15

    The absence of relevant animal models of chronic hepatitis B virus (HBV) infection has hampered the evaluation and development of therapeutic HBV vaccines. In this study, we generated a novel transgenic mouse lineage that expresses human class I and II HLA molecules and the hepatitis B surface antigen (HBsAg). HBsAg and hepatitis B core antigen (HBcAg) administered as plasmid DNAs and recombinant proteins, either alone or in combination, were evaluated as therapeutic vaccine candidates in this mouse model. Our results emphasize the importance of the route of administration in breaking HBsAg tolerance. Although immunizing the transgenic mice with DNA encoding homologous HBsAg was sufficient to induce CD8+ T-cell responses, HBsAg from a heterologous subtype was required to induce a CD4+ T-cell response. Importantly, only prime-boost immunization protocols that combined plasmid DNA injection followed by protein injection induced the production of antibodies against the HBsAg expressed by the transgenic mice. PMID:22591777

  14. The affordances of broken affordances

    DEFF Research Database (Denmark)

    Grünbaum, Martin Gielsgaard; Simonsen, Jakob Grue

    2015-01-01

    We consider the use of physical and virtual objects having one or more affordances associated to simple interactions with them. Based on Kaptelinin and Nardi’s notion of instrumental affordance, we investigate what it means to break an affordance, and the two ensuing questions we deem most...... important: how users may (i) achieve their goals in the presence of such broken affordances, and may (ii) repurpose or otherwise interact with artefacts with broken affordances. We argue that (A) thorough analyses of breakdowns of affordances and their associated signifiers and feedbacks have implication...

  15. An adenoviral cancer vaccine co-encoding a tumor associated antigen together with secreted 4-1BBL leads to delayed tumor progression

    DEFF Research Database (Denmark)

    Ragonnaud, Emeline; Andersson, Anne-Marie C; Pedersen, Anders Elm;

    2016-01-01

    antibody administration. Furthermore, adenovirus encoded 4-1BBL expression has previously been successfully used to enhance responses toward Plasmodium falciparum and Influenza A antigens. We showed that the incorporation of 4-1BBL in the adenovirus vector led to surface expression of 4-1BBL on antigen...... survival compared to the vaccine expressing the membrane form of 4-1BBL. Accordingly, secreted 4-1BBL co-encoded with the Ii linked antigen may offer a simplification compared to administration of drug and vaccine separately....

  16. Antigenicity and Immunogenicity of Salmonella enteritidis: Its Implication for Diagnosis and Development of Local Isolate Vaccine for Poultry

    Directory of Open Access Journals (Sweden)

    Tati Ariyanti

    2008-12-01

    Full Text Available Genus Salmonella consists of more than 2,400 serovars, which can be identified by means of serological method based on the variation of their somatic (O, flagellar (H and capsular antigens (Vi. Salmonella serovars which are able to cause disease in animal or domestic animal are limited, such as: S. pullorum and S. gallinarum which are well adapted to poultry, cause fowl typhoid, S. cholerasuis causes disease in swine. S. typhimurium and S. enteritidis can infect all animals and humans. S. typhimurium and S. enteritidis could be isolated from salmonellosis of poultry, meat, milk and eggs. The prevalence of those isolates within the last two decades tends to increase. Pathogenic Salmonella serovars can infect both animals and humans, colonize the intestinal epithelial cells lead to diarrhoea. Salmonella spp. may enter the lower layer of epithelial cells and the lymphoid vascular system. Humoral antibody and cell mediated immunity responses may develop. Extraintestinal shedding or dissemination of Salmonella spp. may occur and multiply, this may cause latent infections and spread to the environment. Serologic diagnosis of infected animals can be done by means of serum or whole blood agglutination tests with whole cell antigen or ELISA with LPS coated tray, might demonstrate cross reactions among serovars within the one group. ELISA antibody by using fimbrial SEF14 antigen demonstrated specific diagnosis of S. enteritidis infection. The use of S. enteritidis inactive vaccines stimulates high humoral antibody response and protection against challenged homologous serovar within one group (D. The secretory antibody in mucosal surface of intestine and cell mediated immunity were not stimulated after vaccination with inactive Salmonella vaccine. Inactive vaccines (local isolate of S. enteritidis which was developed and evaluated on experimental layer chicken produced protection against challenged homologous and may be used to control vertical

  17. Protective Antigen-Specific Memory B Cells Persist Years after Anthrax Vaccination and Correlate with Humoral Immunity

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    Lori Garman

    2014-08-01

    Full Text Available Anthrax Vaccine Adsorbed (AVA generates short-lived protective antigen (PA specific IgG that correlates with in vitro toxin neutralization and protection from Bacillus anthracis challenge. Animal studies suggest that when PA-specific IgG has waned, survival after spore challenge correlates with an activation of PA-specific memory B cells. Here, we characterize the quantity and the longevity of AVA-induced memory B cell responses in humans. Peripheral blood mononuclear cells (PBMCs from individuals vaccinated ≥3 times with AVA (n = 50 were collected early (3–6 months, n = 27 or late after their last vaccination (2–5 years, n = 23, pan-stimulated, and assayed by ELISPOT for total and PA-specific memory B cells differentiated into antibody secreting cells (ASCs. PA-specific ASC percentages ranged from 0.02% to 6.25% (median: 1.57% and did not differ between early and late post-vaccination individuals. PA-specific ASC percentages correlated with plasma PA-specific IgG (r = 0.42, p = 0.03 and toxin neutralization (r = 0.52, p = 0.003 early post vaccination. PA-specific ASC percentages correlated with supernatant anti-PA both early (r = 0.60, p = 0.001 and late post vaccination (r = 0.71, p < 0.0001. These data suggest PA-specific memory B cell responses are long-lived and can be estimated after recent vaccination by the magnitude and neutralization capacity of the humoral response.

  18. Sequence-based prediction for vaccine strain selection and identification of antigenic variability in foot-and-mouth disease virus.

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    Richard Reeve

    Full Text Available Identifying when past exposure to an infectious disease will protect against newly emerging strains is central to understanding the spread and the severity of epidemics, but the prediction of viral cross-protection remains an important unsolved problem. For foot-and-mouth disease virus (FMDV research in particular, improved methods for predicting this cross-protection are critical for predicting the severity of outbreaks within endemic settings where multiple serotypes and subtypes commonly co-circulate, as well as for deciding whether appropriate vaccine(s exist and how much they could mitigate the effects of any outbreak. To identify antigenic relationships and their predictors, we used linear mixed effects models to account for variation in pairwise cross-neutralization titres using only viral sequences and structural data. We identified those substitutions in surface-exposed structural proteins that are correlates of loss of cross-reactivity. These allowed prediction of both the best vaccine match for any single virus and the breadth of coverage of new vaccine candidates from their capsid sequences as effectively as or better than serology. Sub-sequences chosen by the model-building process all contained sites that are known epitopes on other serotypes. Furthermore, for the SAT1 serotype, for which epitopes have never previously been identified, we provide strong evidence--by controlling for phylogenetic structure--for the presence of three epitopes across a panel of viruses and quantify the relative significance of some individual residues in determining cross-neutralization. Identifying and quantifying the importance of sites that predict viral strain cross-reactivity not just for single viruses but across entire serotypes can help in the design of vaccines with better targeting and broader coverage. These techniques can be generalized to any infectious agents where cross-reactivity assays have been carried out. As the parameterization

  19. Merozoite Surface Antigen 2 Proteins of Babesia bovis Vaccine Breakthrough Isolates Contain a Unique Hypervariable Region Composed of Degenerate Repeats

    Science.gov (United States)

    Berens, Shawn J.; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The merozoite surface antigen 2 (MSA-2) proteins of Babesia bovis are members of the variable merozoite surface antigen (VMSA) family that have been implicated in erythrocyte invasion and are important targets for antibody-mediated blocking of invasion. Extensive sequence variation in another VMSA member, MSA-1, has been shown in all vaccine breakthrough isolates. To test the hypothesis that the msa-2 genes of vaccine breakthrough isolates would also encode a diverse set of proteins, the complete msa-2 locus was characterized from 12 Australian B. bovis strains and isolates, including two vaccine strains and eight vaccine breakthrough isolates, and compared to the loci in previously and newly characterized American strains. In contrast to American strains, the msa-2 loci of all Australian strains and isolates examined contain, in addition to msa-2c, only a solitary gene (designated msa-2a/b) closely related to American strain msa-2a and msa-2b. Nevertheless, the proteins encoded by these genes are quite diverse both between and within geographic regions and harbor evidence of genetic exchange among other VMSA family members, including msa-1. Moreover, all but one of the Australian breakthrough isolate MSA-2a/b proteins is markedly different from the vaccine strain from which immune escape occurred, consistent with their role in strain-specific protective immunity. The densest distribution of polymorphisms occurs in a hypervariable region (HVR) within the carboxy third of the molecule that is highly proline rich. Variation in length and content of the HVR is primarily attributable to differences in the order and number of degenerate nucleotide repeats encoding three motifs of unknown function. PMID:16239512

  20. Blood stage malaria vaccine eliciting high antigen-specific antibody concentrations confers no protection to young children in Western Kenya.

    Directory of Open Access Journals (Sweden)

    Bernhards R Ogutu

    Full Text Available OBJECTIVE: The antigen, falciparum malaria protein 1 (FMP1, represents the 42-kDa C-terminal fragment of merozoite surface protein-1 (MSP-1 of the 3D7 clone of P. falciparum. Formulated with AS02 (a proprietary Adjuvant System, it constitutes the FMP1/AS02 candidate malaria vaccine. We evaluated this vaccine's safety, immunogenicity, and efficacy in African children. METHODS: A randomised, double-blind, Phase IIb, comparator-controlled trial.The trial was conducted in 13 field stations of one mile radii within Kombewa Division, Nyanza Province, Western Kenya, an area of holoendemic transmission of P. falciparum. We enrolled 400 children aged 12-47 months in general good health.Children were randomised in a 1ratio1 fashion to receive either FMP1/AS02 (50 microg or Rabipur(R rabies vaccine. Vaccinations were administered on a 0, 1, and 2 month schedule. The primary study endpoint was time to first clinical episode of P. falciparum malaria (temperature >/=37.5 degrees C with asexual parasitaemia of >/=50,000 parasites/microL of blood occurring between 14 days and six months after a third dose. Case detection was both active and passive. Safety and immunogenicity were evaluated for eight months after first immunisations; vaccine efficacy (VE was measured over a six-month period following third vaccinations. RESULTS: 374 of 400 children received all three doses and completed six months of follow-up. FMP1/AS02 had a good safety profile and was well-tolerated but more reactogenic than the comparator. Geometric mean anti-MSP-1(42 antibody concentrations increased from1.3 microg/mL to 27.3 microg/mL in the FMP1/AS02 recipients, but were unchanged in controls. 97 children in the FMP1/AS02 group and 98 controls had a primary endpoint episode. Overall VE was 5.1% (95% CI: -26% to +28%; p-value = 0.7. CONCLUSIONS: FMP1/AS02 is not a promising candidate for further development as a monovalent malaria vaccine. Future MSP-1(42 vaccine development should focus

  1. Human anti-anthrax protective antigen neutralizing monoclonal antibodies derived from donors vaccinated with anthrax vaccine adsorbed

    OpenAIRE

    Sawada-Hirai, Ritsuko; Jiang, Ivy; Wang, Fei; Sun, Shu Man; Nedellec, Rebecca; Ruther, Paul; Alvarez, Alejandro; Millis, Diane; Morrow, Phillip R.; Kang, Angray S

    2004-01-01

    Background Potent anthrax toxin neutralizing human monoclonal antibodies were generated from peripheral blood lymphocytes obtained from Anthrax Vaccine Adsorbed (AVA) immune donors. The anti-anthrax toxin human monoclonal antibodies were evaluated for neutralization of anthrax lethal toxin in vivo in the Fisher 344 rat bolus toxin challenge model. Methods Human peripheral blood lymphocytes from AVA immunized donors were engrafted into severe combined immunodeficient (SCID) mice. Vaccination w...

  2. A multi-antigen vaccine in combination with an immunotoxin targeting tumor-associated fibroblast for treating murine melanoma

    Science.gov (United States)

    Fang, Jinxu; Hu, Biliang; Li, Si; Zhang, Chupei; Liu, Yarong; Wang, Pin

    2016-01-01

    A therapeutically effective cancer vaccine must generate potent antitumor immune responses and be able to overcome tolerance mechanisms mediated by the progressing tumor itself. Previous studies showed that glycoprotein 100 (gp100), tyrosinase-related protein 1 (TRP1), and tyrosinase-related protein 2 (TRP2) are promising immunogens for melanoma immunotherapy. In this study, we administered these three melanoma-associated antigens via lentiviral vectors (termed LV-3Ag) and found that this multi-antigen vaccine strategy markedly increased functional T-cell infiltration into tumors and generated protective and therapeutic antitumor immunity. We also engineered a novel immunotoxin, αFAP-PE38, capable of targeting fibroblast activation protein (FAP)-expressing fibroblasts within the tumor stroma. When combined with αFAP-PE38, LV-3Ag exhibited greatly enhanced antitumor effects on tumor growth in an established B16 melanoma model. The mechanism of action underlying this combination treatment likely modulates the immune suppressive tumor microenvironment and, consequently, activates cytotoxic CD8+ T cells capable of specifically recognizing and destroying tumor cells. Taken together, these results provide a strong rationale for combining an immunotoxin with cancer vaccines for the treatment of patients with advanced cancer. PMID:27119119

  3. Targeting hepatitis B virus antigens to dendritic cells by heat shock protein to improve DNA vaccine potency

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate a novel DNA vaccination based upon expression of the HBV e antigen fused to a heat shock protein (HSP) as a strategy to enhance DNA vaccine potency.METHODS: A pCMV-HBeAg-HSP DNA vaccine and a control DNA vaccine were generated. Mice were immunized with these different construct. Immune responses were measured 2 wk after a second immunization by a T cell response assay, CTL cytotoxicity assay, and an antibody assay in C57BL/6 and BALB/c mice. CT26-HBeAg tumor cell challenge test in vivo was performed in BALB/c mice to monitor anti-tumor immune responses.RESULTS: In the mice immunized with pCMV-HBe-HSP DNA, superior CTL activity to target HBV-positive target cells was observed in comparison with mice immunized with pCMV-HBeAg (44% ± 5% vs 30% ± 6% in E: T > 50:1, P < 0.05). ELISPOT assays showed a stronger T-cell response from mice immunized with pCMV-HBe-HSP than that from pCMV-HBeAg immunized animals when stimulated either with MHC class Ⅰ or class Ⅱ epitopes derived from HBeAg (74% ± 9% vs 31% ± 6%, P < 0.01). ELISA assays revealed an enhanced HBeAg antibody response from mice immunized with pCMV-HBe-HSP than from those immunized with pCMV-HBeAg. The lowest tumor incidence and the slowest tumor growth were observed in mice immunized with pCMV-HBe-HSP when challenged with CT26-HBeAg.CONCLUSION: The results of this study demonstrate a broad enhancement of antigen-specific CD4+ helper,CD8+ cytotoxic T-cell, and B-cell responses by a novel DNA vaccination strategy. They also proved a stronger antigen-specific immune memory, which may be superior to currently described HBV DNA vaccination strategies for the treatment of chronic HBV infection.

  4. Potential of Translationally Controlled Tumor Protein-Derived Protein Transduction Domains as Antigen Carriers for Nasal Vaccine Delivery.

    Science.gov (United States)

    Bae, Hae-Duck; Lee, Joohyun; Jin, Xing-Hai; Lee, Kyunglim

    2016-09-01

    Nasal vaccination offers a promising alternative to intramuscular (i.m.) vaccination because it can induce both mucosal and systemic immunity. However, its major drawback is poor absorption of large antigens in the nasal epithelium. Protein transduction domains (PTDs), also called cell-penetrating peptides, have been proposed as vehicles for nasal delivery of therapeutic peptides and proteins. Here, we evaluated the potential of a mutant PTD derived from translationally controlled tumor protein (designated TCTP-PTD 13) as an antigen carrier for nasal vaccines. We first compared the l- and d-forms of TCTP-PTD 13 isomers (l- or d-TCTP-PTD 13) as antigen carriers. Studies in mice demonstrated that nasally administered mixtures of the model antigen ovalbumin (OVA) and d-TCTP-PTD 13 induced higher plasma IgG titers and secretory IgA levels in nasal washes than nasally administered OVA alone, OVA/l-TCTP-PTD 13, or i.m.-injected OVA. Plasma IgG subclass responses (IgG1 and IgG2a) of mice nasally administered OVA/d-TCTP-PTD 13 showed that the predominant IgG subclass was IgG1, indicating a Th2-biased immune response. We also used synthetic CpG oligonucleotides (CpG) as a Th1 immune response-inducing adjuvant. Nasally administered CpG plus OVA/d-TCTP-PTD 13 was superior in eliciting systemic and mucosal immune responses compared to those induced by nasally administered OVA/d-TCTP-PTD 13. Furthermore, the OVA/CpG/d-TCTP-PTD 13 combination skewed IgG1 and IgG2a profiles of humoral immune responses toward a Th1 profile. These findings suggest that TCTP-derived PTD is a suitable vehicle to efficiently carry antigens and to induce more powerful antigen-specific immune responses and a more balanced Th1/Th2 response when combined with a DNA adjuvant. PMID:27454469

  5. Enhanced vaccine-induced CD8+ T cell responses to malaria antigen ME-TRAP by fusion to MHC class ii invariant chain.

    Directory of Open Access Journals (Sweden)

    Alexandra J Spencer

    Full Text Available The orthodox role of the invariant chain (CD74; Ii is in antigen presentation to CD4+ T cells, but enhanced CD8+ T cells responses have been reported after vaccination with vectored viral vaccines encoding a fusion of Ii to the antigen of interest. In this study we assessed whether fusion of the malarial antigen, ME-TRAP, to Ii could increase the vaccine-induced CD8+ T cell response. Following single or heterologous prime-boost vaccination of mice with a recombinant chimpanzee adenovirus vector, ChAd63, or recombinant modified vaccinia virus Ankara (MVA, higher frequencies of antigen-specific CD4+ and CD8+ T cells were observed, with the largest increases observed following a ChAd63-MVA heterologous prime-boost regimen. Studies in non-human primates confirmed the ability of Ii-fusion to augment the T cell response, where a 4-fold increase was maintained up to 11 weeks after the MVA boost. Of the numerous different approaches explored to increase vectored vaccine induced immunogenicity over the years, fusion to the invariant chain showed a consistent enhancement in CD8+ T cell responses across different animal species and may therefore find application in the development of vaccines against human malaria and other diseases where high levels of cell-mediated immunity are required.

  6. Establishment of an in vivo potency assay for the recombinant hepatit is B surface antigen in monovalent and combined vaccines

    Directory of Open Access Journals (Sweden)

    Mabel Izquierdo-López

    2014-12-01

    Full Text Available In this paper the development of potency assay in animals (mice was made, with the objective of demonstrating the immunogenic power of the recombinant Hepatitis B surface antigen in monovalent and combined vaccines, produced at the Center of Genetic Engineering and Biotechnology. The potency test is a parameter in quality control and it is also a tool to demonstrate the consistency of the production process. Parameters such as duration of the test, number of animals in the test, as well as different areas for the maintenance of the animals were evaluated. The results on the applicability of the potency test, to two presentations of the vaccines; monovalent Heberbiovac HB and pentavalent liquid in one vial Heberpenta-L are shown, for which specificity studies, evaluating different vaccine lots, the behavior of linearity, and parallelism, as well as establishing quality specification of the test were performed. This assay led to the obtainment of reliable results for the vaccines evaluated, the consistent evaluation of the immunogenic power and the monitoring of different production processes.

  7. MVA-based H5N1 vaccine affords cross-clade protection in mice against influenza A/H5N1 viruses at low doses and after single immunization.

    Directory of Open Access Journals (Sweden)

    Joost H C M Kreijtz

    Full Text Available Human infections with highly pathogenic avian influenza viruses of the H5N1 subtype, frequently reported since 2003, result in high morbidity and mortality. It is feared that these viruses become pandemic, therefore the development of safe and effective vaccines is desirable. MVA-based H5N1 vaccines already proved to be effective when two immunizations with high doses were used. Dose-sparing strategies would increase the number of people that can be vaccinated when the amount of vaccine preparations that can be produced is limited. Furthermore, protective immunity is induced ideally after a single immunization. Therefore the minimal requirements for induction of protective immunity with a MVA-based H5N1 vaccine were assessed in mice. To this end, mice were vaccinated once or twice with descending doses of a recombinant MVA expressing the HA gene of influenza virus A/Vietnam/1194/04. The protective efficacy was determined after challenge infection with the homologous clade 1 virus and a heterologous virus derived from clade 2.1, A/Indonesia/5/05 by assessing weight loss, virus replication and histopathological changes. It was concluded that MVA-based vaccines allowed significant dose-sparing and afford cross-clade protection, also after a single immunization, which are favorable properties for an H5N1 vaccine candidate.

  8. Immunotoxicity of aflatoxin B1: Impairment of the cell-mediated response to vaccine antigen and modulation of cytokine expression

    International Nuclear Information System (INIS)

    Aflatoxin B1 (AFB1), a mycotoxin produced by Aspergillus flavus or A. parasiticus, is a frequent contaminant of food and feed. This toxin is hepatotoxic and immunotoxic. The present study analyzed in pigs the influence of AFB1 on humoral and cellular responses, and investigated whether the immunomodulation observed is produced through interference with cytokine expression. For 28 days, pigs were fed a control diet or a diet contaminated with 385, 867 or 1807 μg pure AFB1/kg feed. At days 4 and 15, pigs were vaccinated with ovalbumin. AFB1 exposure, confirmed by an observed dose-response in blood aflatoxin-albumin adduct, had no major effect on humoral immunity as measured by plasma concentrations of total IgA, IgG and IgM and of anti-ovalbumin IgG. Toxin exposure did not impair the mitogenic response of lymphocytes but delayed and decreased their specific proliferation in response to the vaccine antigen, suggesting impaired lymphocyte activation in pigs exposed to AFB1. The expression level of pro-inflammatory (TNF-α, IL-1β, IL-6, IFN-γ) and regulatory (IL-10) cytokines was assessed by real-time PCR in spleen. A significant up-regulation of all 5 cytokines was observed in spleen from pigs exposed to the highest dose of AFB1. In pigs exposed to the medium dose, IL-6 expression was increased and a trend towards increased IFN-γ and IL-10 was observed. In addition we demonstrate that IL-6 impaired in vitro the antigenic- but not the mitogenic-induced proliferation of lymphocytes from control pigs vaccinated with ovalbumin. These results indicate that AFB1 dietary exposure decreases cell-mediated immunity while inducing an inflammatory response. These impairments in the immune response could participate in failure of vaccination protocols and increased susceptibility to infections described in pigs exposed to AFB1

  9. Expression of immunogenic epitopes of hepatitis B surface antigen with hybrid flagellin proteins by a vaccine strain of Salmonella.

    OpenAIRE

    Wu, J Y; Newton, S; Judd, A; Stocker, B; Robinson, W S

    1989-01-01

    A nonvirulent Salmonella dublin flagellin-negative, aromatic-dependent live vaccine strain has been used to express hepatitis B virus surface antigen epitopes in an immunogenic form. The envelope proteins of the virion are encoded by the S gene, which contains the pre-S1, pre-S2, and S coding regions. Synthetic oligonucleotides corresponding to amino acid residues S-(122-137) and pre-S2-(120-145) were inserted in-frame into the hypervariable region of a cloned Salmonella flagellin gene, and t...

  10. Universal Influenza Vaccines, a Dream to Be Realized Soon

    Directory of Open Access Journals (Sweden)

    Han Zhang

    2014-04-01

    Full Text Available Due to frequent viral antigenic change, current influenza vaccines need to be re-formulated annually to match the circulating strains for battling seasonal influenza epidemics. These vaccines are also ineffective in preventing occasional outbreaks of new influenza pandemic viruses. All these challenges call for the development of universal influenza vaccines capable of conferring broad cross-protection against multiple subtypes of influenza A viruses. Facilitated by the advancement in modern molecular biology, delicate antigen design becomes one of the most effective factors for fulfilling such goals. Conserved epitopes residing in virus surface proteins including influenza matrix protein 2 and the stalk domain of the hemagglutinin draw general interest for improved antigen design. The present review summarizes the recent progress in such endeavors and also covers the encouraging progress in integrated antigen/adjuvant delivery and controlled release technology that facilitate the development of an affordable universal influenza vaccine.

  11. Loss of T Cell Antigen Recognition Arising from Changes in Peptide and Major Histocompatibility Complex Protein Flexibility: Implications for Vaccine Design

    Energy Technology Data Exchange (ETDEWEB)

    Insaidoo, Francis K.; Borbulevych, Oleg Y.; Hossain, Moushumi; Santhanagopolan, Sujatha M.; Baxter, Tiffany K.; Baker, Brian M. (Notre)

    2012-05-08

    Modification of the primary anchor positions of antigenic peptides to improve binding to major histocompatibility complex (MHC) proteins is a commonly used strategy for engineering peptide-based vaccine candidates. However, such peptide modifications do not always improve antigenicity, complicating efforts to design effective vaccines for cancer and infectious disease. Here we investigated the MART-1{sub 27-35} tumor antigen, for which anchor modification (replacement of the position two alanine with leucine) dramatically reduces or ablates antigenicity with a wide range of T cell clones despite significantly improving peptide binding to MHC. We found that anchor modification in the MART-1{sub 27-35} antigen enhances the flexibility of both the peptide and the HLA-A*0201 molecule. Although the resulting entropic effects contribute to the improved binding of the peptide to MHC, they also negatively impact T cell receptor binding to the peptide {center_dot} MHC complex. These results help explain how the 'anchor-fixing' strategy fails to improve antigenicity in this case, and more generally, may be relevant for understanding the high specificity characteristic of the T cell repertoire. In addition to impacting vaccine design, modulation of peptide and MHC flexibility through changes to antigenic peptides may present an evolutionary strategy for the escape of pathogens from immune destruction.

  12. Antigen design enhances the immunogenicity of Semliki Forest virus-based therapeutic human papillomavirus vaccines

    NARCIS (Netherlands)

    Ip, P. P.; Boerma, A.; Walczak, M.; Oosterhuis, K.; Haanen, J. B.; Schumacher, T. N.; Nijman, H. W.; Daemen, T.

    2015-01-01

    Cellular immunity against cancer can be achieved with viral vector-and DNA-based immunizations. In preclinical studies, cancer vaccines are very potent, but in clinical trials these potencies are not achieved yet. Thus, a rational approach to improve cancer vaccines is warranted. We previously demon

  13. Reduced antibody responses against Plasmodium falciparum vaccine candidate antigens in the presence of Trichuris trichiura

    DEFF Research Database (Denmark)

    Esen, Meral; Mordmüller, Benjamin; de Salazar, Pablo Martinez;

    2012-01-01

    BACKGROUND: Helminth infections are highly prevalent in the tropics and may have an effect on immune responses to vaccines due to their immunomodulatory effect. The prevalence of helminth infections in young children, the target group for malaria and most other vaccines, is high. Therefore we ass...

  14. Hepatitis B surface antigen positivity after twinrix vaccination: a case report.

    Science.gov (United States)

    Lee, Yirang; Kim, Jae-Seok; Park, Ji-Young; Kim, Soo Young; Hwang, In Hong; Cho, Hyoun Chan

    2014-01-01

    Travelers might have an increased risk of hepatitis B virus (HBV) infection. We report a case of prolonged transient hepatitis B surface antigenemia in a healthy Canadian female 8 days after administration of a combined hepatitis A and hepatitis B vaccine. Travel health providers providing hepatitis B vaccines need to be aware of this phenomenon and educate their patients accordingly. PMID:24861218

  15. Size-exclusion HPLC provides a simple, rapid, and versatile alternative method for quality control of vaccines by characterizing the assembly of antigens.

    Science.gov (United States)

    Yang, Yanli; Li, Hao; Li, Zhengjun; Zhang, Yan; Zhang, Songping; Chen, Yi; Yu, Mengran; Ma, Guanghui; Su, Zhiguo

    2015-02-25

    The assembly of antigen structure is often crucial to the potency of vaccines. Currently adopted methods like animal testing and ultracentrifugation take long time and are difficult to automate for multiple samples. Here we develop a size-exclusion high-performance liquid chromatography (SE-HPLC) method to characterize the assembly of antigen structure during both manufacturing process and storage. Three important vaccine antigens including inactivated foot and mouth disease virus (FMDV), which is a virus vaccine; and two virus-like particles (VLPs) vaccines involving hepatitis B core antigen (HBcAg) VLPs, and hepatitis B surface antigen (HBsAg) VLPs, were successfully analyzed using commercially available TSK gel columns with pore size above 45nm. Combined with other analytical methods including SDS-PAGE, dynamic light scattering, wavelength scan, and multi-angle laser light scattering, the SE-HPLC method was proven to be a simple, rapid, and reliable tool for antigen particles assembly analysis. Specifically, for FMDV whole virus particle, SE-HPLC was used to analyze 146S content in vaccine preparations and the thermal dissociation of the 146S. For HBcAg-VLPs that are expressed in recombinant Escherichia coli, its expression level during cell culture process was quantitatively monitored by SE-HPLC. The SE-HPLC also showed applicability for quality check of HBsAg vaccine preparations by monitoring the product consistency of different lot number and the product stability during storage. Results shown in this work clearly demonstrated that SE-HPLC method has potential as a versatile alternative technology for control of the final product by both manufacturers and the regulatory agencies. PMID:25604799

  16. Design and Antigenic Epitopes Prediction of a New Trial Recombinant Multiepitopic Rotaviral Vaccine: In Silico Analyses.

    Science.gov (United States)

    Jafarpour, Sima; Ayat, Hoda; Ahadi, Ali Mohammad

    2015-01-01

    Rotavirus is the major etiologic factor of severe diarrheal disease. Natural infection provides protection against subsequent rotavirus infection and diarrhea. This research presents a new vaccine designed based on computational models. In this study, three types of epitopes are considered-linear, conformational, and combinational-in a proposed model protein. Several studies on rotavirus vaccines have shown that VP6 and VP4 proteins are good candidates for vaccine production. In the present study, a fusion protein was designed as a new generation of rotavirus vaccines by bioinformatics analyses. This model-based study using ABCpred, BCPREDS, Bcepred, and Ellipro web servers showed that the peptide presented in this article has the necessary properties to act as a vaccine. Prediction of linear B-cell epitopes of peptides is helpful to investigate whether these peptides are able to activate humoral immunity. PMID:25965449

  17. Assessment by electron-microscopy of recombinant Vibrio cholerae and Salmonella vaccine strains expressing enterotoxigenic Escherichia coli-specific surface antigens.

    Science.gov (United States)

    Ziethlow, V; Favre, D; Viret, J-F; Frey, J; Stoffel, M H

    2008-03-01

    Diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) requires adhesion of microorganisms to enterocytes. Hence, a promising approach to immunoprophylaxis is to elicit antibodies against colonisation factor antigens (CFAs). Genes encoding the most prevalent ETEC-specific surface antigens were cloned into Vibrio cholerae and Salmonella vaccine strains. Expression of surface antigens was assessed by electron-microscopy. Whereas negative staining was effective in revealing CFA/I and CS3, but not CS6, immunolabelling allowed identification of all surface antigens examined. The V. cholerae vaccine strain CVD103 did not express ETEC-specific colonisation factors, whereas CVD103-HgR expressed CS3 only. However, expression of both CFA/I and CS3 was demonstrated in Salmonella Ty21a. PMID:18093230

  18. A phase II trial of personalized peptide vaccination in castration-resistant prostate cancer patients: prolongation of prostate-specific antigen doubling time

    OpenAIRE

    Noguchi, Masanori; MORIYA, FUKUKO; SUEKANE, SHIGETAKA; Ohnishi, Rei; Matsueda, Satoko; Sasada, Tetsuro; Yamada, Akira; Itoh, Kyogo

    2013-01-01

    Background Cancer vaccine is one of the attractive treatment modalities for patients with castration-resistant prostate cancer (CRPC). However, because of delayed immune responses, its clinical benefits, besides for overall survival (OS), are not well captured by the World Health Organization (WHO) and Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Several surrogate markers for evaluation of cancer vaccine, including prostate-specific antigen doubling time (PSADT), are curren...

  19. Combining Viral Vectored and Protein-in-adjuvant Vaccines Against the Blood-stage Malaria Antigen AMA1: Report on a Phase 1a Clinical Trial

    OpenAIRE

    Susanne H. Hodgson; Choudhary, Prateek; Elias, Sean C; Milne, Kathryn H; Thomas W Rampling; Biswas, Sumi; Ian D Poulton; Miura, Kazutoyo; Douglas, Alexander D.; Alanine, Daniel GW; Illingworth, Joseph J.; de Cassan, Simone C.; ZHU, DAMING; Nicosia, Alfredo; Long, Carole A.

    2014-01-01

    The development of effective vaccines against difficult disease targets will require the identification of new subunit vaccination strategies that can induce and maintain effective immune responses in humans. Here we report on a phase 1a clinical trial using the AMA1 antigen from the blood-stage Plasmodium falciparum malaria parasite delivered either as recombinant protein formulated with Alhydrogel adjuvant with and without CPG 7909, or using recombinant vectored vaccines—chimpanzee adenovir...

  20. Immunological Correlates for Protection against Intranasal Challenge of Bacillus anthracis Spores Conferred by a Protective Antigen-Based Vaccine in Rabbits

    OpenAIRE

    Weiss, Shay; Kobiler, David; Levy, Haim; Marcus, Hadar; Pass, Avi; Rothschild, Nili; Altboum, Zeev

    2006-01-01

    Correlates between immunological parameters and protection against Bacillus anthracis infection in animals vaccinated with protective antigen (PA)-based vaccines could provide surrogate markers to evaluate the putative protective efficiency of immunization in humans. In previous studies we demonstrated that neutralizing antibody levels serve as correlates for protection in guinea pigs (S. Reuveny et al., Infect. Immun. 69:2888-2893, 2001; H. Marcus et al., Infect. Immun. 72:3471-3477, 2004). ...

  1. Cell-mediated immunity elicited by the blood stage malaria vaccine apical membrane antigen 1 in Malian adults: Results of a Phase I randomized trial

    OpenAIRE

    Lyke, Kirsten E; Daou, Modibo; DIARRA, ISSA; Kone, Abdoulaye; Kouriba, Bourema; Thera, Mohamadou A.; Dutta, Sheetij; Lanar, David E.; Heppner, D Gray; Doumbo, Ogobara K.; Plowe, Christopher V.; Sztein, Marcelo B.

    2009-01-01

    The development of a safe and effective malaria vaccine is impeded by the complexity of the Plasmodium life cycle. A vaccine that elicits both cell-mediated and humoral immune responses might be needed for protection against this multistage parasitic infection. Apical membrane antigen 1 (AMA-1) plays a key role in erythrocytic invasion but is also expressed in sporozoites and in late stage liver schizonts, where it may provide a target of protective cell-mediated immunity (CMI). A Phase 1 tri...

  2. Utilizing the antigen capsid-incorporation strategy for the development of adenovirus serotype 5-vectored vaccine approaches.

    Science.gov (United States)

    Gu, Linlin; Farrow, Anitra L; Krendelchtchikov, Alexandre; Matthews, Qiana L

    2015-01-01

    Adenovirus serotype 5 (Ad5) has been extensively modified with traditional transgene methods for the vaccine development. The reduced efficacies of these traditionally modified Ad5 vectors in clinical trials could be primarily correlated with Ad5 pre-existing immunity (PEI) among the majority of the population. To promote Ad5-vectored vaccine development by solving the concern of Ad5 PEI, the innovative Antigen Capsid-Incorporation strategy has been employed. By merit of this strategy, Ad5-vectored we first constructed the hexon shuttle plasmid HVR1-KWAS-HVR5-His6/pH5S by subcloning the hypervariable region (HVR) 1 of hexon into a previously constructed shuttle plasmid HVR5-His6/pH5S, which had His6 tag incorporated into the HVR5. This HVR1 DNA fragment containing a HIV epitope ELDKWAS was synthesized. HVR1-KWAS-HVR5-His6/pH5S was then linearized and co-transformed with linearized backbone plasmid pAd5/∆H5 (GL) , for homologous recombination. This recombined plasmid pAd5/H5-HVR1-KWAS-HVR5-His6 was transfected into cells to generate the viral vector Ad5/H5-HVR1-KWAS-HVR5-His6. This vector was validated to have qualitative fitness indicated by viral physical titer (VP/ml), infectious titer (IP/ml) and corresponding VP/IP ratio. Both the HIV epitope and His6 tag were surface-exposed on the Ad5 capsid, and retained epitope-specific antigenicity of their own. A neutralization assay indicated the ability of this divalent vector to circumvent neutralization by Ad5-positive sera in vitro. Mice immunization demonstrated the generation of robust humoral immunity specific to the HIV epitope and His6. This proof-of-principle study suggested that the protocol associated with the Antigen Capsid-Incorporation strategy could be feasibly utilized for the generation of Ad5-vectored vaccines by modifying different capsid proteins. This protocol could even be further modified for the generation of rare-serotype adenovirus-vectored vaccines. PMID:25993057

  3. Differential Effects of Prior Exposure to Environmental Mycobacteria on Vaccination with Mycobacterium bovis BCG or a Recombinant BCG Strain Expressing RD1 Antigens

    OpenAIRE

    Demangel, Caroline; Garnier, Thierry; Rosenkrands, Ida; Cole, Stewart T.

    2005-01-01

    In silico analysis reveals that most protective antigens expressed by the antituberculous vaccine Mycobacterium bovis BCG (BCG) are conserved in M. avium, supporting the hypothesis that exposure to environmental mycobacteria generates cross-reactive immune responses blocking BCG activity. We investigated the impact of sensitization with M. avium, M. scrofulaceum, or M. vaccae on the protective efficacy of a recombinant BCG strain expressing RD1 antigens (BCG::RD1), using a mouse model of expe...

  4. Induction of Immune Tolerance in Asthmatic Mice by Vaccination with DNA Encoding an Allergen–Cytotoxic T Lymphocyte-Associated Antigen 4 Combination ▿

    OpenAIRE

    Zhang, Fang; Huang, Gang; Hu, Bo; Song, Yong; Shi, Yi

    2011-01-01

    Allergen-specific immunotherapy is a potential treatment for allergic diseases. We constructed an allergen–cytotoxic T lymphocyte-associated antigen 4 (CTLA-4)-encoding DNA vaccine, administered it directly to antigen-presenting cells (APCs), and investigated its ability and mechanisms to ameliorate allergic airway inflammation in an asthmatic mouse model. An allergen-CTLA-4 DNA plasmid (OVA-CTLA-4-pcDNA3.1) encoding an ovalbumin (OVA) and the mouse CTLA-4 extracellular domain was constructed...

  5. Hematopoietic stem cells and progenitors of chronic myeloid leukemia express leukemia-associated antigens: implications for the graft-versus-leukemia effect and peptide vaccine-based immunotherapy

    OpenAIRE

    Yong, Agnes S.M.; Keyvanfar, Keyvan; Eniafe, Rhoda; Savani, Bipin N.; Rezvani, Katayoun; Sloand, Elaine M.; Goldman, John M.; Barrett, A. John

    2008-01-01

    The cure of chronic myeloid leukemia (CML) patients following allogeneic stem cell transplantation (SCT) is attributed to graft-versus-leukemia (GVL) effects targeting alloantigens and/or leukemia-associated antigens (LAA) on leukemia cells. To assess the potential of LAA-peptide vaccines in eliminating leukemia in CML patients, we measured WT1, PR3, ELA2 and PRAME expression in CD34+ progenitor subpopulations in CML patients and compared them with minor histocompatibility antigens (mHAgs) HA...

  6. Vaccinations

    Science.gov (United States)

    ... vaccinated? For many years, a set of annual vaccinations was considered normal and necessary for dogs and ... to protect for a full year. Consequently, one vaccination schedule will not work well for all pets. ...

  7. An Alternative and Effective HIV Vaccination Approach Based on Inhibition of Antigen Presentation Attenuators in Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available BACKGROUND: Current efforts to develop HIV vaccines that seek to stimulate immune responses have been disappointing, underscoring the inability of natural immune responses to control HIV-1 infection. Here we tested an alternative strategy to induce anti-HIV immune responses by inhibiting a host's natural immune inhibitor. METHODS AND FINDINGS: We used small interfering RNA (siRNA to inhibit suppressor of cytokine signaling (SOCS 1, a key negative regulator of the JAK/STAT pathway, and investigated the effect of this silencing on the ability of dendritic cells (DCs to induce anti-HIV-1 immunity. We found that SOCS1-silenced DCs broadly induced enhanced HIV-1 envelope (Env-specific CD8(+ cytotoxic T lymphocytes and CD4(+ T helper cells, as well as antibody responses, in mice. Importantly, SOCS1-silenced DCs were more resistant to HIV Env-mediated suppression and were capable of inducing memory HIV Env-specific antibody and T cell responses. SOCS1-restricted signaling, as well as production of proinflammatory cytokines such as interleukin-12 by DCs, play a critical role in regulating the anti-HIV immune response. Furthermore, the potency of HIV DNA vaccination is significantly enhanced by coimmunization with SOCS1 siRNA expressor DNA. CONCLUSIONS: This study demonstrates that SOCS1 functions as an antigen presentation attenuator to control both HIV-1-specific humoral and cellular responses. This study represents the first, to our knowledge, attempt to elicit HIV-specific T cell and antibody responses by inhibiting a host's antigen presentation attenuator, which may open a new and alternative avenue to develop effective therapeutic and prophylactic HIV vaccines.

  8. Production of a Recombinant Dengue Virus 2 NS5 Protein and Potential Use as a Vaccine Antigen.

    Science.gov (United States)

    Alves, Rúbens Prince Dos Santos; Pereira, Lennon Ramos; Fabris, Denicar Lina Nascimento; Salvador, Felipe Scassi; Santos, Robert Andreata; Zanotto, Paolo Marinho de Andrade; Romano, Camila Malta; Amorim, Jaime Henrique; Ferreira, Luís Carlos de Souza

    2016-06-01

    Dengue fever is caused by any of the four known dengue virus serotypes (DENV1 to DENV4) that affect millions of people worldwide, causing a significant number of deaths. There are vaccines based on chimeric viruses, but they still are not in clinical use. Anti-DENV vaccine strategies based on nonstructural proteins are promising alternatives to those based on whole virus or structural proteins. The DENV nonstructural protein 5 (NS5) is the main target of anti-DENV T cell-based immune responses in humans. In this study, we purified a soluble recombinant form of DENV2 NS5 expressed in Escherichia coli at large amounts and high purity after optimization of expression conditions and purification steps. The purified DENV2 NS5 was recognized by serum from DENV1-, DENV2-, DENV3-, or DENV4-infected patients in an epitope-conformation-dependent manner. In addition, immunization of BALB/c mice with NS5 induced high levels of NS5-specific antibodies and expansion of gamma interferon- and tumor necrosis factor alpha-producing T cells. Moreover, mice immunized with purified NS5 were partially protected from lethal challenges with the DENV2 NGC strain and with a clinical isolate (JHA1). These results indicate that the recombinant NS5 protein preserves immunological determinants of the native protein and is a promising vaccine antigen capable of inducing protective immune responses. PMID:27030586

  9. Response of health care workers with isolated antibody to hepatitis B core antigen to hepatitis B vaccine.

    Science.gov (United States)

    Chiarakul, Supawadee; Eunumjitkul, Krissana; Vorapimol, Ar-Reerat; Kaewkungwal, Jaranit; Chimparlee, Nitinan; Poovorawan, Yong

    2011-07-01

    Isolated hepatitis B core antibody (antiHBc) without hepatitis B surface antigen (HBsAg) or hepatitis B surface antibody (antiHBs) is found during routine screening for hepatitis B virus (HBV) markers. Isolated antiHBc may indicate immunity against HBV or occult infection. To determine the immune response of health care workers (HCWs) with isolated antiHBc, HCWs were divided into two groups. A single dose of recombinant hepatitis B (HB) vaccine was administered to HCWs with isolated antiHBc (n = 36) and healthy HCWs (n = 20) seronegative for HBsAg, antiHBc and antiHBs. One month later, the subjects were tested for antiHBs. Twenty-one of 36 HCW (58.3%) in the antiHBc group had antiHBs, while only 1 of 20 HCW (5.0%) in the seronegative control group had a detectable antiHBs titer exceeding 10 mIU/ml. The antiHBs response in HCWs with antiHBc was significantly higher than in the seronegative group. The subjects' sera were tested for HBV DNA by nested PCR. Of those with antiHBc, 4 had detectable HBV DNA (occult HBV infection). None of these 4 responded to the vaccine. Therefore, the response elicited by a single dose of HB vaccine administered to patients with antiHBc may serve as an indicator of occult HBV infection. PMID:22299465

  10. Network Affordances

    DEFF Research Database (Denmark)

    Samson, Audrey; Soon, Winnie

    2015-01-01

    This paper examines the notion of network affordance within the context of network art. Building on Gibson's theory (Gibson, 1979) we understand affordance as the perceived and actual parameters of a thing. We expand on Gaver's affordance of predictability (Gaver, 1996) to include ecological...... and computational parameters of unpredictability. We illustrate the notion of unpredictability by considering four specific works that were included in a network art exhibiton, SPEED SHOW [2.0] Hong Kong. The paper discusses how the artworks are contingent upon the parameteric relations (Parisi, 2013......), of the network. We introduce network affordance as a dynamic framework that could articulate the experienced tension arising from the (visible) symbolic representation of computational processes and its hidden occurrences. We base our proposal on the experience of both organising the SPEED SHOW and participating...

  11. Successful Renal Transplantation in a Patient with HBS Antigen Positivity Caused By Hepatitis B Vaccination

    OpenAIRE

    Yildirim, Tolga; Şeref Rahmi YILMAZ; Ercan TÜRKMEN; Mahmut ALTINDAL; Fazıl Tuncay AKİ; Erdem, Yunus; Ünal YASAVUL; Çetin TURGAN

    2013-01-01

    Hepatitis B infection is one of the causes of morbidity and mortality in long-term survivors of renal transplantation. Hepatitis B vaccination is recommended for HbsAg and antiHbs antibody negative end stage renal disease patients before transplantation. Serologies to detect hepatitis B infection are included in the routine assessment of renal transplant candidates. However false positive assays for HbsAg can be recognized after hepatitis B vaccination. Hemodialysis patients have been found t...

  12. Immunogenicity and Protection Efficacy of Subunit-based Smallpox Vaccines Using Variola Major Antigens

    OpenAIRE

    Sakhatskyy, Pavlo; Wang, Shixia; Zhang, Chuanyou; Chou, Te-Hui; Kishko, Michael; Lu, Shan

    2007-01-01

    The viral strain responsible for smallpox infection is variola major (VARV). As a result of the successful eradication of smallpox with the vaccinia virus (VACV), the general population is no longer required to receive a smallpox vaccine, and will have no protection against smallpox. This lack of immunity is a concern due to the potential for use of smallpox as a biological weapon. Considerable progress has been made in the development of subunit-based smallpox vaccines resulting from the ide...

  13. A new adenovirus based vaccine vector expressing an Eimeria tenella derived TLR agonist improves cellular immune responses to an antigenic target.

    Directory of Open Access Journals (Sweden)

    Daniel M Appledorn

    Full Text Available BACKGROUND: Adenoviral based vectors remain promising vaccine platforms for use against numerous pathogens, including HIV. Recent vaccine trials utilizing Adenovirus based vaccines expressing HIV antigens confirmed induction of cellular immune responses, but these responses failed to prevent HIV infections in vaccinees. This illustrates the need to develop vaccine formulations capable of generating more potent T-cell responses to HIV antigens, such as HIV-Gag, since robust immune responses to this antigen correlate with improved outcomes in long-term non-progressor HIV infected individuals. METHODOLOGY/PRINCIPAL FINDINGS: In this study we designed a novel vaccine strategy utilizing an Ad-based vector expressing a potent TLR agonist derived from Eimeria tenella as an adjuvant to improve immune responses from a [E1-]Ad-based HIV-Gag vaccine. Our results confirm that expression of rEA elicits significantly increased TLR mediated innate immune responses as measured by the influx of plasma cytokines and chemokines, and activation of innate immune responding cells. Furthermore, our data show that the quantity and quality of HIV-Gag specific CD8(+ and CD8(- T-cell responses were significantly improved when coupled with rEA expression. These responses also correlated with a significantly increased number of HIV-Gag derived epitopes being recognized by host T cells. Finally, functional assays confirmed that rEA expression significantly improved antigen specific CTL responses, in vivo. Moreover, we show that these improved responses were dependent upon improved TLR pathway interactions. CONCLUSION/SIGNIFICANCE: The data presented in this study illustrate the potential utility of Ad-based vectors expressing TLR agonists to improve clinical outcomes dependent upon induction of robust, antigen specific immune responses.

  14. An adenoviral cancer vaccine co-encoding a tumor associated antigen together with secreted 4-1BBL leads to delayed tumor progression.

    Science.gov (United States)

    Ragonnaud, Emeline; Andersson, Anne-Marie C; Pedersen, Anders Elm; Laursen, Henriette; Holst, Peter J

    2016-04-19

    Previous studies have shown promising results when using an agonistic anti-4-1BB antibody treatment against established tumors. While this is promising, this type of treatment can induce severe side effects. Therefore, we decided to incorporate the membrane form of 4-1BB ligand (4-1BBL) in a replicative deficient adenovirus vaccine expressing the invariant chain (Ii) adjuvant fused to a tumor associated antigen (TAA). The Ii adjuvant increases and prolongs TAA specific CD8+ T cells as previously shown and local expression of 4-1BBL was chosen to avoid the toxicity associated with systemic antibody administration. Furthermore, adenovirus encoded 4-1BBL expression has previously been successfully used to enhance responses toward Plasmodium falciparum and Influenza A antigens. We showed that the incorporation of 4-1BBL in the adenovirus vector led to surface expression of 4-1BBL on antigen presenting cells, but it did not enhance T cell responses in mice towards the Ii linked antigen. In tumor-bearing mice, our vaccine was found to decrease the frequency of TAA specific CD8+ T cells, but this difference did not alter the therapeutic efficacy. In order to reconcile our findings with the previous reports of increased anti-cancer efficacy using systemically delivered 4-1BB agonists, we incorporated a secreted version of 4-1BBL (Fc-4-1BBL) in our vaccine and co-expressed it with the Ii linked to TAA. In tumor bearing mice, this vaccine initially delayed tumor growth and slightly increased survival compared to the vaccine expressing the membrane form of 4-1BBL. Accordingly, secreted 4-1BBL co-encoded with the Ii linked antigen may offer a simplification compared to administration of drug and vaccine separately. PMID:27004934

  15. Vaccination with BM86, subolesin and akirin protective antigens for the control of tick infestations in white tailed deer and red deer.

    Science.gov (United States)

    Carreón, Diana; de la Lastra, José M Pérez; Almazán, Consuelo; Canales, Mario; Ruiz-Fons, Francisco; Boadella, Mariana; Moreno-Cid, Juan A; Villar, Margarita; Gortázar, Christian; Reglero, Manuel; Villarreal, Ricardo; de la Fuente, José

    2012-01-01

    Red deer (Cervus elaphus) and white-tailed deer (Odocoileus virginianus) are hosts for different tick species and tick-borne pathogens and play a role in tick dispersal and maintenance in some regions. These factors stress the importance of controlling tick infestations in deer and several methods such as culling and acaricide treatment have been used. Tick vaccines are a cost-effective alternative for tick control that reduced cattle tick infestations and tick-borne pathogens prevalence while reducing the use of acaricides. Our hypothesis is that vaccination with vector protective antigens can be used for the control of tick infestations in deer. Herein, three experiments were conducted to characterize (1) the antibody response in red deer immunized with recombinant BM86, the antigen included in commercial tick vaccines, (2) the antibody response and control of cattle tick infestations in white-tailed deer immunized with recombinant BM86 or tick subolesin (SUB) and experimentally infested with Rhipicephalus (Boophilus) microplus, and (3) the antibody response and control of Hyalomma spp. and Rhipicephalus spp. field tick infestations in red deer immunized with mosquito akirin (AKR), the SUB ortholog and candidate protective antigen against different tick species and other ectoparasites. The results showed that deer produced an antibody response that correlated with the reduction in tick infestations and was similar to other hosts vaccinated previously with these antigens. The overall vaccine efficacy was similar between BM86 (E=76%) and SUB (E=83%) for the control of R. microplus infestations in white-tailed deer. The field trial in red deer showed a 25-33% (18-40% when only infested deer were considered) reduction in tick infestations, 14-20 weeks after the first immunization. These results demonstrated that vaccination with vector protective antigens could be used as an alternative method for the control of tick infestations in deer to reduce tick populations

  16. Modified tumour antigen-encoding mRNA facilitates the analysis of naturally occurring and vaccine-induced CD4 and CD8 T cells in cancer patients.

    Science.gov (United States)

    Knights, Ashley J; Nuber, Natko; Thomson, Christopher W; de la Rosa, Olga; Jäger, Elke; Tiercy, Jean-Marie; van den Broek, Maries; Pascolo, Steve; Knuth, Alexander; Zippelius, Alfred

    2009-03-01

    The development of effective anti-cancer vaccines requires precise assessment of vaccine-induced immunity. This is often hampered by low ex vivo frequencies of antigen-specific T cells and limited defined epitopes. This study investigates the applicability of modified, in vitro-transcribed mRNA encoding a therapeutically relevant tumour antigen to analyse T cell responses in cancer patients. In this study transfection of antigen presenting cells, by mRNA encoding the tumour antigen NY-ESO-1, was optimised and applied to address spontaneous and vaccine-induced T cell responses in cancer patients. Memory CD8+ T cells from lung cancer patients having detectable humoral immune responses directed towards NY-ESO-1 could be efficiently detected in peripheral blood. Specific T cells utilised a range of different T cell receptors, indicating a polyclonal response. Specific killing of a panel of NY-ESO-1 expressing tumour cell lines indicates recognition restricted to several HLA allelic variants, including a novel HLA-B49 epitope. Using a modified mRNA construct targeting the translated antigen to the secretory pathway, detection of NY-ESO-1-specific CD4+ T cells in patients could be enhanced, which allowed the in-depth characterisation of established T cell clones. Moreover, broad CD8+ and CD4+ T cell responses covering multiple epitopes were detected following mRNA stimulation of patients treated with a recombinant vaccinia/fowlpox NY-ESO-1 vaccine. This approach allows for a precise monitoring of responses to tumour antigens in a setting that addresses the breadth and magnitude of antigen-specific T cell responses, and that is not limited to a particular combination of known epitopes and HLA-restrictions. PMID:18663444

  17. Impaired Antigen-Specific Immune Response to Vaccines in Children with Antibody Production Defects

    OpenAIRE

    Szczawinska-Poplonyk, Aleksandra; Breborowicz, Anna; Samara, Husam; Ossowska, Lidia; Dworacki, Grzegorz

    2015-01-01

    The impaired synthesis of antigen-specific antibodies, which is indispensable for an adaptive immune response to infections, is a fundamental pathomechanism that leads to clinical manifestations in children with antibody production defects. The aim of this study was to evaluate the synthesis of antigen-specific antibodies following immunization in relation to peripheral blood B cell subsets in young children with hypogammaglobulinemia. Twenty-two children, aged from 8 to 61 months, with a def...

  18. Tumor antigen specific iTreg accumulate in the tumor microenvironment and suppress therapeutic vaccination

    OpenAIRE

    Schreiber, Taylor H; Wolf, Dietlinde; Bodero, Maria; Podack, Eckhard

    2012-01-01

    Tumor specific antigens (TSA) provide an opportunity to mobilize therapeutic immune responses against cancer. To evade such responses, tumor development in immunocompetent hosts is accompanied by acquisition of both active and passive mechanisms of immune suppression, including recruitment of CD4+FoxP3+ regulatory T cells (Treg). Thymic derived Treg (nTreg) may recognize self-antigens in the tumor microenvironment, while peripherally induced Treg (iTreg) may preferentially recognize the same ...

  19. DNA Vaccines Encoding Antigen Targeted to MHC Class II Induce Influenza-Specific CD8(+) T Cell Responses, Enabling Faster Resolution of Influenza Disease.

    Science.gov (United States)

    Lambert, Laura; Kinnear, Ekaterina; McDonald, Jacqueline U; Grodeland, Gunnveig; Bogen, Bjarne; Stubsrud, Elisabeth; Lindeberg, Mona M; Fredriksen, Agnete Brunsvik; Tregoning, John S

    2016-01-01

    Current influenza vaccines are effective but imperfect, failing to cover against emerging strains of virus and requiring seasonal administration to protect against new strains. A key step to improving influenza vaccines is to improve our understanding of vaccine-induced protection. While it is clear that antibodies play a protective role, vaccine-induced CD8(+) T cells can improve protection. To further explore the role of CD8(+) T cells, we used a DNA vaccine that encodes antigen dimerized to an immune cell targeting module. Immunizing CB6F1 mice with the DNA vaccine in a heterologous prime-boost regime with the seasonal protein vaccine improved the resolution of influenza disease compared with protein alone. This improved disease resolution was dependent on CD8(+) T cells. However, DNA vaccine regimes that induced CD8(+) T cells alone were not protective and did not boost the protection provided by protein. The MHC-targeting module used was an anti-I-E(d) single chain antibody specific to the BALB/c strain of mice. To test the role of MHC targeting, we compared the response between BALB/c, C57BL/6 mice, and an F1 cross of the two strains (CB6F1). BALB/c mice were protected, C57BL/6 were not, and the F1 had an intermediate phenotype; showing that the targeting of antigen is important in the response. Based on these findings, and in agreement with other studies using different vaccines, we conclude that, in addition to antibody, inducing a protective CD8 response is important in future influenza vaccines. PMID:27602032

  20. DNA vaccines

    OpenAIRE

    Coban, Cevayir; Kobiyama, Kouji; Jounai, Nao; Tozuka, Miyuki; Ishii, Ken J.

    2013-01-01

    Since the introduction of DNA vaccines two decades ago, this attractive strategy has been hampered by its low immunogenicity in humans. Studies conducted to improve the immunogenicity of DNA vaccines have shown that understanding the mechanism of action of DNA vaccines might be the key to successfully improving their immunogenicity. Our current understanding is that DNA vaccines induce innate and adaptive immune responses in two ways: (1) encoded protein (or polypeptide) antigen(s) by the DNA...

  1. Specificity for the tumor-associated self-antigen WT1 drives the development of fully functional memory T cells in the absence of vaccination.

    Science.gov (United States)

    Pospori, Constandina; Xue, Shao-An; Holler, Angelika; Voisine, Cecile; Perro, Mario; King, Judith; Fallah-Arani, Farnaz; Flutter, Barry; Chakraverty, Ronjon; Stauss, Hans J; Morris, Emma C

    2011-06-23

    Recently, vaccines against the Wilms Tumor antigen 1 (WT1) have been tested in cancer patients. However, it is currently not known whether physiologic levels of WT1 expression in stem and progenitor cells of normal tissue result in the deletion or tolerance induction of WT1-specific T cells. Here, we used an human leukocyte antigen-transgenic murine model to study the fate of human leukocyte antigen class-I restricted, WT1-specific T cells in the thymus and in the periphery. Thymocytes expressing a WT1-specific T-cell receptor derived from high avidity human CD8 T cells were positively selected into the single-positive CD8 population. In the periphery, T cells specific for the WT1 antigen differentiated into CD44-high memory phenotype cells, whereas T cells specific for a non-self-viral antigen retained a CD44(low) naive phenotype. Only the WT1-specific T cells, but not the virus-specific T cells, displayed rapid antigen-specific effector function without prior vaccination. Despite long-term persistence of WT1-specific memory T cells, the animals did not develop autoimmunity, and the function of hematopoietic stem and progenitor cells was unimpaired. This is the first demonstration that specificity for a tumor-associated self-antigen may drive differentiation of functionally competent memory T cells. PMID:21447831

  2. Nanolipoprotein Particles (NLPs) as Versatile Vaccine Platforms for Co-delivery of Multiple Adjuvants with Subunit Antigens from Burkholderia spp. and F. tularensis - Annual Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, N. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-04-16

    The goal of this proposal is to demonstrate that co-localization of protein subunit antigens and adjuvants on nanolipoprotein particles (NLPs) can increase the protective efficacy of recombinant subunit antigens from Burkholderia spp. and Francisella tularensis against an aerosol challenge. NLPs are are biocompatible, high-density lipoprotein mimetics that are amenable to the incorporation of multiple, chemically-disparate adjuvant and antigen molecules. We hypothesize that the ability to co-localize optimized adjuvant formulations with subunit antigens within a single particle will enhance the stimulation and activation of key immune effector cells, increasing the protective efficacy of subunit antigen-based vaccines. While Burkholderia spp. and F. tularensis subunit antigens are the focus of this proposal, we anticipate that this approach is applicable to a wide range of DOD-relevant biothreat agents. The F344 rat aerosol challenge model for F. tularensis has been successfully established at Battelle under this contract, and Year 3 efficacy studies performed at Battelle demonstrated that an NLP vaccine formulation was able to enhance survival of female F344 rats relative to naïve animals. In addition, Year 3 focused on the incorporation of multiple Burkholderia antigens (both polysaccharides and proteins) onto adjuvanted NLPs, with immunological analysis poised to begin in the next quarter.

  3. Hepatitis B Surface Antigen S Gene is an Effective Carrier Molecule for Developing GnRH DNA Immunocastration Vaccine in Mice.

    Science.gov (United States)

    Han, Y G; Ye, W J; Liu, G Q; Jiang, X P; Ijaz, N; Zhao, J Y; Tesema, B

    2016-06-01

    Relatively molecular mass of GnRH antigens is small and hence needs to couple to a large carrier molecule to enhance its immunogenicity. This study investigated whether hepatitis B surface antigen S (HBsAg-S) gene can be used as an effective carrier molecule for developing GnRH DNA immunocastration vaccine. Two copies of human GnRH gene were fused with HBsAg-S gene for constructing a recombinant plasmid pVAX-HBsAg-S-2GnRH that coded for 27 kDa target fusion protein. Ten male mice were divided into two equal groups, treatment and control. The vaccine (50 μg/mice) prepared in saline solution was injected into male mice at weeks 0, 1, 2, 4 and 7 of the experiment. Vaccine's efficacy was evaluated in terms of GnRH-specific IgG antibody response, plasma testosterone levels, testicular weight and extent of the testicular tissue damage. The specific anti-GnRH antibody titre in vaccinated animals was significantly higher than in controls in only 4th week of immunization (p vaccinated animals showed lower testicular weight than those of the controls (p vaccinated animals was suppressed. In conclusion, in this study, the engineered plasmid to be used as a GnRH DNA vaccine induced antibody response and suppressed spermatogenesis in mice. This suggests that HBsAg-S gene can be an effective carrier molecule for developing GnRH DNA immunocastration vaccine when relatively molecular mass of the aimed antigens is small. PMID:27157596

  4. Clinical assessment of a novel recombinant simian adenovirus ChAdOx1 as a vectored vaccine expressing conserved Influenza A antigens.

    Science.gov (United States)

    Antrobus, Richard D; Coughlan, Lynda; Berthoud, Tamara K; Dicks, Matthew D; Hill, Adrian Vs; Lambe, Teresa; Gilbert, Sarah C

    2014-03-01

    Adenoviruses are potent vectors for inducing and boosting cellular immunity to encoded recombinant antigens. However, the widespread seroprevalence of neutralizing antibodies to common human adenovirus serotypes limits their use. Simian adenoviruses do not suffer from the same drawbacks. We have constructed a replication-deficient chimpanzee adenovirus-vectored vaccine expressing the conserved influenza antigens, nucleoprotein (NP), and matrix protein 1 (M1). Here, we report safety and T-cell immunogenicity following vaccination with this novel recombinant simian adenovirus, ChAdOx1 NP+M1, in a first in human dose-escalation study using a 3+3 study design, followed by boosting with modified vaccinia virus Ankara expressing the same antigens in some volunteers. We demonstrate ChAdOx1 NP+M1 to be safe and immunogenic. ChAdOx1 is a promising vaccine vector that could be used to deliver vaccine antigens where strong cellular immune responses are required for protection. PMID:24374965

  5. Montanide ISA 71 VG adjuvant enhances antibody and cell-ediated immune responses to profilin subunit antigen vaccination and promotes protection against Eimeria acervulina and Eimeria tenella

    Science.gov (United States)

    The present study was conducted to investigate the immunoenhancing effects of ISA 71 VG adjuvant on profilin subunit antigen vaccination. Broiler chickens were immunized subcutaneously with a purified Eimeria acervulina recombinant profilin protein, either alone or mixed with ISA 71 VG, and host imm...

  6. Control of ticks resistant to immunization with Bm86 in cattle vaccinated with the recombinant antigen Bm95 isolated from the cattle tick, Boophilus microplus.

    Science.gov (United States)

    García-García, J C; Montero, C; Redondo, M; Vargas, M; Canales, M; Boue, O; Rodríguez, M; Joglar, M; Machado, H; González, I L; Valdés, M; Méndez, L; de la Fuente, J

    2000-04-28

    The recombinant Bm86-containing vaccine Gavac(TM) against the cattle tick Boophilus microplus has proved its efficacy in a number of experiments, especially when combined with acaricides in an integrated manner. However, tick isolates such as the Argentinean strain A, show low susceptibility to this vaccine. In this paper we report on the isolation of the Bm95 gene from the B. microplus strain A, which was cloned and expressed in the yeast Pichia pastoris producing a glycosylated and particulated recombinant protein. This new antigen was effective against different tick strains in a pen trial, including the B. microplus strain A, resistant to vaccination with Bm86. A Bm95-based vaccine was used to protect cattle against tick infestations under production conditions, lowering the number of ticks on vaccinated animals and, therefore, reducing the frequency of acaricide treatments. The Bm95 antigen from strain A was able to protect against infestations with Bm86-sensitive and Bm86-resistant tick strains, thus suggesting that Bm95 could be a more universal antigen to protect cattle against infestations by B. microplus strains from different geographical areas. PMID:10717348

  7. Antigenic analysis of classical swine fever virus E2 glycoprotein using pig antibodies identifies residues contributing to antigenic variation of the vaccine C-strain and group 2 strains circulating in China

    Directory of Open Access Journals (Sweden)

    Peng Jinrong

    2010-12-01

    Full Text Available Abstract Background Glycoprotein E2, the immunodominant protein of classical swine fever virus (CSFV, can induce neutralizing antibodies and confer protective immunity in pigs. Our previous phylogenetic analysis showed that subgroup 2.1 viruses branched away from subgroup 1.1, the vaccine C-strain lineage, and became dominant in China. The E2 glycoproteins of CSFV C-strain and recent subgroup 2.1 field isolates are genetically different. However, it has not been clearly demonstrated how this diversity affects antigenicity of the protein. Results Antigenic variation of glycoprotein E2 was observed not only between CSFV vaccine C-strain and subgroup 2.1 strains, but also among strains of the same subgroup 2.1 as determined by ELISA-based binding assay using pig antisera to the C-strain and a representative subgroup 2.1 strain QZ-07 currently circulating in China. Antigenic incompatibility of E2 proteins markedly reduced neutralization efficiency against heterologous strains. Single amino acid substitutions of D705N, L709P, G713E, N723S, and S779A on C-strain recombinant E2 (rE2 proteins significantly increased heterologous binding to anti-QZ-07 serum, suggesting that these residues may be responsible for the antigenic variation between the C-strain and subgroup 2.1 strains. Notably, a G713E substitution caused the most dramatic enhancement of binding of the variant C-strain rE2 protein to anti-QZ-07 serum. Multiple sequence alignment revealed that the glutamic acid residue at this position is conserved within group 2 strains, while the glycine residue is invariant among the vaccine strains, highlighting the role of the residue at this position as a major determinant of antigenic variation of E2. A variant Simpson's index analysis showed that both codons and amino acids of the residues contributing to antigenic variation have undergone similar diversification. Conclusions These results demonstrate that CSFV vaccine C-strain and group 2 strains

  8. Malaria Vaccine Candidate Diversity Offers Challenges and Opportunities for Effective Vaccine Development

    Directory of Open Access Journals (Sweden)

    Kamal CHOWDHURY

    2009-06-01

    Full Text Available Malaria is one of the most deadly diseases caused by protozoan parasites of genus Plasmodium. It affects 300-500 million people annually, of which more than a million lives are lost; among them majority under 5 years of age. By conventional wisdom, the immune mechanisms responsible for protection against malaria will require a multiple of 10-15 antigen targets for proper protection against various stages of malarial infection. Such large number of targets cannot be delivered to humans, by this method. Moreover, each antigen is reported to be highly polymorphic in nature and the malaria-affected populations live in economically poor part of the world. Development of anti-malarial vaccines is therefore, a very tough challenge from technical, delivery and affordability points of view. Technical challenges include identification of epitopes / antigens against appropriate targets, construction of DNA vector(s that will express properly folded functional protein. Vaccine delivery challenges include developing an easy method to deliver multiple doses within a short period of time to infants and children of less than five years of age. Affordability challenges include development of cost-effective vaccines that can be stored at room temperature and be easily delivered. Although the complex life cycle of Plasmodium is challenging for anti-malarial vaccine development, it also offers a lot of antigen targets (opportunities to combat malaria. Information on anti-malarial vaccine candidates, DNA constructs and cost-effective delivery mechanism will be discussed.

  9. A polyvalent vaccine for high-risk prostate patients: "are more antigens better?"

    DEFF Research Database (Denmark)

    Slovin, Susan F; Ragupathi, Govind; Fernandez, Celina; Diani, Meghan; Jefferson, Matthew P; Wilton, Andrew; Kelly, W Kevin; Morris, Michael; Solit, David; Clausen, Henrik; Livingston, Philip; Scher, Howard I

    2007-01-01

    We have shown the immunogenicity and safety of synthetic carbohydrate vaccines when conjugated to the carrier keyhole limpet hemocyanin (KLH) and given with the adjuvant, QS-21, in patients with biochemically relapsed prostate cancer. To determine whether immune response could be further enhanced...... detected. We address the relevance of the multivalent approach for prostate cancer treatment.......We have shown the immunogenicity and safety of synthetic carbohydrate vaccines when conjugated to the carrier keyhole limpet hemocyanin (KLH) and given with the adjuvant, QS-21, in patients with biochemically relapsed prostate cancer. To determine whether immune response could be further enhanced...

  10. Enhanced protective efficacy against Mycobacterium tuberculosis afforded by BCG prime-DNA boost regimen in an early challenge mouse model is associated with increased splenic interleukin-2-producing CD4 T-cell frequency post-vaccination.

    Science.gov (United States)

    Kang, Han; Yuan, Qin; Ma, Hui; Hu, Zhi-Dong; Han, De-Ping; Wu, Kang; Lowrie, Douglas B; Fan, Xiao-Yong

    2014-12-01

    The development of improved vaccines and vaccination strategies against Mycobacterium tuberculosis has been hindered by a limited understanding of the immune correlates of anti-tuberculosis protective immunity. Simple measurement of interferon-γ frequency or production per se does not provide adequate prediction of immune protection. In this study, we examined the relationship between T-cell immune responses and protective efficacy conferred by the heterologous vaccination strategy, bacillus Calmette-Guérin (BCG) prime-Ag85A DNA boost (B/D), in an early challenge mouse model of pulmonary tuberculosis. The results demonstrated that mice vaccinated with the B/D regimen had a significantly reduced bacillary load compared with BCG-vaccinated mice, and the reduction in colony-forming units was associated with decreased pathology and lower levels of inflammatory cytokines in the infected lungs. Further analysis of immunogenicity showed that the superior protection afforded by the B/D regimen was associated with significantly increased frequency of splenic interleukin-2 (IL-2) -producing CD4 T cells and increased IL-2 production when measured as integrated mean fluorescence intensity post-vaccination as well. These data suggest that measurement of elevated frequency of IL-2-producing CD4 T cells or IL-2 production in the spleens of vaccinated mice can predict vaccine efficacy, at least in the B/D strategy, and add to the accumulating body of evidence suggesting that BCG prime-boost strategies may be a useful approach to the control of M. tuberculosis infection. PMID:24965530

  11. The structural basis for T-antigen hydrolysis by Streptococcus pneumoniae: a target for structure-based vaccine design.

    Science.gov (United States)

    Caines, Matthew E C; Zhu, Haizhong; Vuckovic, Marija; Willis, Lisa M; Withers, Stephen G; Wakarchuk, Warren W; Strynadka, Natalie C J

    2008-11-14

    Streptococcus pneumoniae endo-alpha-N-acetylgalactosaminidase is a cell surface-anchored glycoside hydrolase from family GH101 involved in the breakdown of mucin type O-linked glycans. The 189-kDa mature enzyme specifically hydrolyzes the T-antigen disaccharide from extracellular host glycoproteins and is representative of a broadly important class of virulence factors that have remained structurally uncharacterized due to their large size and highly modular nature. Here we report a 2.9 angstroms resolution crystal structure that remarkably captures the multidomain architecture and characterizes a catalytic center unexpectedly resembling that of alpha-amylases. Our analysis presents a complete model of glycoprotein recognition and provides a basis for the structure-based design of novel Streptococcus vaccines and therapeutics. PMID:18784084

  12. Nanolipoprotein Particles (NLPs) as Versatile Vaccine Platforms for Co-delivery of Multiple Adjuvants with Subunit Antigens from Burkholderia spp. and F. tularensis - Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, N. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-13

    The goal of this proposal is to demonstrate that colocalization of protein subunit antigens and adjuvants on nanolipoprotein particles (NLPs) can increase the protective efficacy of subunit antigens from Burkholderia spp. and Francisella tularensis against an aerosol challenge. In the third quarter of the third year, F344 rats vaccinated with adjuvanted NLP formulations were challenged with F. tularensis SCHU S4 at Battelle. Preliminary data indicate that up to 65% of females vaccinated intranasally with an NLP-based formulation survived this challenge, compared to only 20% survival of naïve animals. In addition, NLPs were successfully formulated with Burkholderia protein antigens. IACUC approval for immunological assessments in BALB/c mice was received and we anticipate that these assessments will begin by March 2015, pending ACURO approval.

  13. Immunochemical characterization and purification of Sm-97 a Schistosoma manosin antigen monospecifically recognized by antibodies from mice protectively immunized with a nonliving vaccine

    International Nuclear Information System (INIS)

    Mice protected against Shistosoma mansoni infection by intradermal (i.d.) vaccination with nonliving schistosomula or soluble extracts of larval or adult schistosomes (SCHLARP and SWAP, respectively) produce antibodies that react by Western blot analysis with one antigen of M/sub r/ (x 10-3) 97 in SWAP prepared in the presence of protease inhibitors and two antigens of M/sub r/ (x 10-3) 95 and 78 in SWAP prepared in their absence. Vaccine antibodies also immunoprecipitated a single 97k molecule, with a pI of 5.5, from detergent extracts of [35S]methionine-labeled schistosomes. Three hybridomas, produced from spleen cells of i.d. immunized mice, all recognized both the 95k/78k doublet and one 97k antigen, indicating that the two lower M/sub r/ components are degradation products of the same 97k molecule. 125I-concanavalin a bound weakly to purified Sm-97, indicating that this antigen is minimally glycosylated. Competitive radioimmunoassays performed with 125I-labeled monoclonal antibodies and purified antigen defined at least two distinct epitopes on Sm-97. Antibodies from i.d. vaccinated mice recognized both monoclonal antibody-defined epitopes, whereas anti-Sm-97 antibodies in chronic infection sera recognized neither. Finally, purified Sm-97 was shown to elicit delayed-type hypersensitivity in i.d. vaccinated mice, suggesting that this molecule is also capable of evoking cell-mediated responses, a finding consistent with its proposed function as a vaccine immunogen

  14. Assessment of cathepsin D and L-like proteinases of poultry red mite, Dermanyssus gallinae (De Geer), as potential vaccine antigens.

    Science.gov (United States)

    Bartley, Kathryn; Huntley, John F; Wright, Harry W; Nath, Mintu; Nisbet, Alasdair J

    2012-05-01

    Vaccination is a feasible strategy for controlling the haematophagous poultry red mite Dermanyssus gallinae. A cDNA library enriched for genes upregulated after feeding was created to identify potential vaccine antigens. From this library, a gene (Dg-CatD-1) encoding a 383 amino acid protein (Dg-CatD-1) with homology to cathepsin D lysosomal aspartyl proteinases was identified as a potential vaccine candidate. A second gene (Dg-CatL-1) encoding a 341 amino acid protein (Dg-CatL-1) with homology to cathepsin L cysteine proteinases was also selected for further study. IgY obtained from naturally infested hens failed to detect Dg-CatD-1 suggesting that it is a concealed antigen. Conversely, Dg-CatL-1 was detected by IgY derived from natural-infestation, indicating that infested hens are exposed to Dg-CatL-1. Mortality rates 120 h after mites had been fed anti-Dg-CatD-1 were significantly higher than those fed control IgY (PF<0·01). In a survival analysis, fitting a proportional hazards model to the time of death of mites, anti-Dg-CatD-1 and anti-Dg-CatL-1 IgY had 4·42 and 2·13 times higher risks of dying compared with controls (PF<0·05). Dg-CatD-1 and L-1 both have potential as vaccine antigens as part of a multi-component vaccine and have the potential to be improved as vaccine antigens using alternative expression systems. PMID:22310226

  15. Vesicular Stomatitis Virus glycoprotein G carrying a tandem dimer of Foot and Mouth Disease Virus antigenic site A can be used as DNA and peptide vaccine for cattle.

    Science.gov (United States)

    Capozzo, Alejandra V; Wilda, Maximiliano; Bucafusco, Danilo; de los Ángeles Lavoria, María; Franco-Mahecha, Olga L; Mansilla, Florencia C; Pérez-Filgueira, Daniel M; Grigera, Pablo R

    2011-11-01

    Effective Foot and Mouth Disease Virus (FMDV) peptide vaccines for cattle have two major constraints: resemblance of one or more of the multiple conformations of the major VP1 antigenic sites to induce neutralizing antibodies, and stimulation of T cells despite the variable bovine-MHC polymorphism. To overcome these limitations, a chimeric antigen was developed, using Vesicular Stomatitis Virus glycoprotein (VSV-G) as carrier protein of an in tandem-dimer of FMDV antigenic site A (ASA), the major epitope on the VP1 capsid protein (aa 139-149, FMDV-C3 serotype). The G-ASA construct was expressed in the Baculovirus system to produce a recombinant protein (DEL BAC) (cloned in pCDNA 3.1 plasmid) (Invitrogen Corporation, Carlsbad, CA) and was also prepared as a DNA vaccine (pC DEL). Calves vaccinated with both immunogens elicited antibodies that recognized the ASA in whole virion and were able to neutralize FMDV infectivity in vitro. After two vaccine doses, DEL BAC induced serum neutralizing titers compatible with an "expected percentage of protection" above 90%. Plasmid pC DEL stimulated FMDV specific humoral responses earlier than DEL BAC, though IgG1 to IgG2 ratios were lower than those induced by both DEL BAC and inactivated FMDV-C3 after the second dose. DEL BAC induced FMDV-specific secretion of IFN-γ in peripheral blood mononuclear cells of outbred cattle immunized with commercial FMDV vaccine, suggesting its capacity to recall anamnestic responses mediated by functional T cell epitopes. The results show that exposing FMDV-VP1 major neutralizing antigenic site in the context of N-terminal sequences of the VSV G protein can overcome the immunological limitations of FMDV-VP1 peptides as effective protein and DNA vaccines for cattle. PMID:21889542

  16. Secretion of protective antigens by tissue-stage nematode larvae revealed by proteomic analysis and vaccination-induced sterile immunity.

    Science.gov (United States)

    Hewitson, James P; Ivens, Al C; Harcus, Yvonne; Filbey, Kara J; McSorley, Henry J; Murray, Janice; Bridgett, Stephen; Ashford, David; Dowle, Adam A; Maizels, Rick M

    2013-08-01

    Gastrointestinal nematode parasites infect over 1 billion humans, with little evidence for generation of sterilising immunity. These helminths are highly adapted to their mammalian host, following a developmental program through successive niches, while effectively down-modulating host immune responsiveness. Larvae of Heligmosomoides polygyrus, for example, encyst in the intestinal submucosa, before emerging as adult worms into the duodenal lumen. Adults release immunomodulatory excretory-secretory (ES) products, but mice immunised with adult H. polygyrus ES become fully immune to challenge infection. ES products of the intestinal wall 4th stage (L4) larvae are similarly important in host-parasite interactions, as they readily generate sterile immunity against infection, while released material from the egg stage is ineffective. Proteomic analyses of L4 ES identifies protective antigen targets as well as potential tissue-phase immunomodulatory molecules, using as comparators the adult ES proteome and a profile of H. polygyrus egg-released material. While 135 proteins are shared between L4 and adult ES, 72 are L4 ES-specific; L4-specific proteins correspond to those whose transcription is restricted to larval stages, while shared proteins are generally transcribed by all life cycle forms. Two protein families are more heavily represented in the L4 secretome, the Sushi domain, associated with complement regulation, and the ShK/SXC domain related to a toxin interfering with T cell signalling. Both adult and L4 ES contain extensive but distinct arrays of Venom allergen/Ancylostoma secreted protein-Like (VAL) members, with acetylcholinesterases (ACEs) and apyrase APY-3 particularly abundant in L4 ES. Serum antibodies from mice vaccinated with L4 and adult ES react strongly to the VAL-1 protein and to ACE-1, indicating that these two antigens represent major vaccine targets for this intestinal nematode. We have thus defined an extensive and novel repertoire of H

  17. Secretion of protective antigens by tissue-stage nematode larvae revealed by proteomic analysis and vaccination-induced sterile immunity.

    Directory of Open Access Journals (Sweden)

    James P Hewitson

    2013-08-01

    Full Text Available Gastrointestinal nematode parasites infect over 1 billion humans, with little evidence for generation of sterilising immunity. These helminths are highly adapted to their mammalian host, following a developmental program through successive niches, while effectively down-modulating host immune responsiveness. Larvae of Heligmosomoides polygyrus, for example, encyst in the intestinal submucosa, before emerging as adult worms into the duodenal lumen. Adults release immunomodulatory excretory-secretory (ES products, but mice immunised with adult H. polygyrus ES become fully immune to challenge infection. ES products of the intestinal wall 4th stage (L4 larvae are similarly important in host-parasite interactions, as they readily generate sterile immunity against infection, while released material from the egg stage is ineffective. Proteomic analyses of L4 ES identifies protective antigen targets as well as potential tissue-phase immunomodulatory molecules, using as comparators the adult ES proteome and a profile of H. polygyrus egg-released material. While 135 proteins are shared between L4 and adult ES, 72 are L4 ES-specific; L4-specific proteins correspond to those whose transcription is restricted to larval stages, while shared proteins are generally transcribed by all life cycle forms. Two protein families are more heavily represented in the L4 secretome, the Sushi domain, associated with complement regulation, and the ShK/SXC domain related to a toxin interfering with T cell signalling. Both adult and L4 ES contain extensive but distinct arrays of Venom allergen/Ancylostoma secreted protein-Like (VAL members, with acetylcholinesterases (ACEs and apyrase APY-3 particularly abundant in L4 ES. Serum antibodies from mice vaccinated with L4 and adult ES react strongly to the VAL-1 protein and to ACE-1, indicating that these two antigens represent major vaccine targets for this intestinal nematode. We have thus defined an extensive and novel

  18. Combining viral vectored and protein-in-adjuvant vaccines against the blood-stage malaria antigen AMA1: report on a phase 1a clinical trial.

    Science.gov (United States)

    Hodgson, Susanne H; Choudhary, Prateek; Elias, Sean C; Milne, Kathryn H; Rampling, Thomas W; Biswas, Sumi; Poulton, Ian D; Miura, Kazutoyo; Douglas, Alexander D; Alanine, Daniel Gw; Illingworth, Joseph J; de Cassan, Simone C; Zhu, Daming; Nicosia, Alfredo; Long, Carole A; Moyle, Sarah; Berrie, Eleanor; Lawrie, Alison M; Wu, Yimin; Ellis, Ruth D; Hill, Adrian V S; Draper, Simon J

    2014-12-01

    The development of effective vaccines against difficult disease targets will require the identification of new subunit vaccination strategies that can induce and maintain effective immune responses in humans. Here we report on a phase 1a clinical trial using the AMA1 antigen from the blood-stage Plasmodium falciparum malaria parasite delivered either as recombinant protein formulated with Alhydrogel adjuvant with and without CPG 7909, or using recombinant vectored vaccines--chimpanzee adenovirus ChAd63 and the orthopoxvirus MVA. A variety of promising "mixed-modality" regimens were tested. All volunteers were primed with ChAd63, and then subsequently boosted with MVA and/or protein-in-adjuvant using either an 8- or 16-week prime-boost interval. We report on the safety of these regimens, as well as the T cell, B cell, and serum antibody responses. Notably, IgG antibody responses primed by ChAd63 were comparably boosted by AMA1 protein vaccine, irrespective of whether CPG 7909 was included in the Alhydrogel adjuvant. The ability to improve the potency of a relatively weak aluminium-based adjuvant in humans, by previously priming with an adenoviral vaccine vector encoding the same antigen, thus offers a novel vaccination strategy for difficult or neglected disease targets when access to more potent adjuvants is not possible. PMID:25156127

  19. Hepatitis B vaccination.

    Science.gov (United States)

    Romanò, Luisa; Paladini, Sara; Galli, Cristina; Raimondo, Giovanni; Pollicino, Teresa; Zanetti, Alessandro R

    2015-01-01

    Hepatitis B virus is a worldwide leading cause of acute and chronic liver disease including cirrhosis and hepatocellular carcinoma. Effective vaccines have been available since the early '80s and vaccination has proved highly successful in reducing the disease burden, the development of the carrier state and the HB-related morbidity and mortality in the countries where vaccination has been implemented.   Neutralizing (protective) antibodies (anti-HBs) induced by vaccination are targeted largely towards the amino acid hydrophilic region, referred to as the common a determinant which is present on the outer protein coat or surface antigen (HBsAg), spanning amino acids 124-149. This provides protection against all HBV genotypes (from A to H) and is responsible for the broad immunity afforded by hepatitis B vaccination. Thus, alterations of residues within this region of the surface antigen may determine conformational changes that can allow replication of the mutated HBV in vaccinated people. An important mutation in the surface antigen region was identified in Italy some 25 years ago in infants born to HBsAg carrier mothers who developed breakthrough infections despite having received HBIG and vaccine at birth. This virus had a point mutation from guanosine to adenosine at nucleotide position 587, resulting in aa substitution from glycine (G) to arginine (R) at position 145 in the a determinant. Since the G145R substitution alters the projecting loop (aa 139-147) of the a determinant, the neutralizing antibodies induced by vaccination are no longer able to recognize the mutated epitope. Beside G145R, other S-gene mutations potentially able to evade neutralizing anti-HBs and infect vaccinated people have been described worldwide. In addition, the emergence of Pol mutants associated with resistance to treatment with nucleos(t)ide analogues can select viruses with crucial changes in the overlapping S-gene, potentially able to alter the S protein immunoreactivity. Thus

  20. Affordances revisited

    DEFF Research Database (Denmark)

    Dohn, Nina Bonderup

    2009-01-01

    argued, is a problem for both design and empirical research. Because HCI discussions of the concept have informed CSCL, views presented within this discourse are discussed. A Merleau-Pontian account of affordances is developed, building on his view of the human being as always already being-in-the world...

  1. Antigenicity and Diagnostic Potential of Vaccine Candidates in Human Chagas Disease

    OpenAIRE

    Shivali Gupta; Xianxiu Wan; Zago, Maria P.; Martinez Sellers, Valena C.; Silva, Trevor S.; Dadjah Assiah; Monisha Dhiman; Sonia Nuñez; Petersen, John R; Vázquez-Chagoyán, Juan C.; Jose G Estrada-Franco; Nisha Jain Garg

    2013-01-01

    BACKGROUND: Chagas disease, caused by Trypanosoma cruzi, is endemic in Latin America and an emerging infectious disease in the US and Europe. We have shown TcG1, TcG2, and TcG4 antigens elicit protective immunity to T. cruzi in mice and dogs. Herein, we investigated antigenicity of the recombinant proteins in humans to determine their potential utility for the development of next generation diagnostics for screening of T. cruzi infection and Chagas disease. METHODS AND RESULTS: Sera samples f...

  2. Anti-cattle tick vaccines: Many candidate antigens, but will a commercially viable product emerge?

    Science.gov (United States)

    This is an invited paper from the editor-in-chief of International Journal for Parasitology who requested a Current Opinion manuscript to discuss the status of anti-cattle tick vaccine research. Arguably the world's most significant arthropod pest of cattle, control of the cattle tick, Rhipicephalus...

  3. BCG Δzmp1 vaccine induces enhanced antigen specific immune responses in cattle.

    Science.gov (United States)

    Khatri, Bhagwati; Whelan, Adam; Clifford, Derek; Petrera, Agnese; Sander, Peter; Vordermeier, H Martin

    2014-02-01

    Mycobacterium bovis (M. bovis) causes major economy and public health problem in numerous countries. In Great Britain, despite the use of a test-and-slaughter strategy, the incidence of bovine tuberculosis (bTB) in cattle has steadily risen in recent years. One strategy being considered to reduce the burden of bTB in cattle is the development of an efficient vaccine. The only current potentially available vaccine against tuberculosis, live attenuated M. bovis bacille Calmette-Guérin (BCG), has demonstrated variable efficacy in both humans and cattle and the development of improved vaccination strategies for cattle is a research priority. In this study we assessed the immunogenicity in cattle of two recombinant BCG strains, namely BCG Pasteur Δzmp1::aph and BCG Danish Δzmp1. By applying a recently defined predictive immune-correlate of protection (T cell memory responses measured by cultured ELISPOT), we have compared these two recombinant BCG with wild-type BCG Danish SSI. Our results demonstrated that both strains induced superior T cell memory responses compared to wild-type BCG. These data provide support for the prioritisation of testing BCG Danish Δzmp1 in vaccination/M. bovis challenge studies to determine its protective efficacy. PMID:24394444

  4. A Challenge for the Development of Malaria Vaccines: Polymorphic Target Antigens

    OpenAIRE

    Sutherland, C.

    2007-01-01

    Parasites of the genus Plasmodium cause many hundreds of millions of cases of malaria worldwide optimism that in the future effective vaccination will join the current strategies of preventive and therapeutic uses of antimalarials, and of reduction in human–vector contact, as part of the global malaria control toolkit.

  5. Immune responses induced by gene gun or intramuscular injection of DNA vaccines that express immunogenic regions of the serine repeat antigen from Plasmodium falciparum.

    Science.gov (United States)

    Belperron, A A; Feltquate, D; Fox, B A; Horii, T; Bzik, D J

    1999-10-01

    The liver- and blood-stage-expressed serine repeat antigen (SERA) of Plasmodium falciparum is a candidate protein for a human malaria vaccine. We compared the immune responses induced in mice immunized with SERA-expressing plasmid DNA vaccines delivered by intramuscular (i.m.) injection or delivered intradermally by Gene Gun immunization. Mice were immunized with a pcdna3 plasmid encoding the entire 47-kDa domain of SERA (amino acids 17 to 382) or the N-terminal domain (amino acids 17 to 110) of SERA. Minimal antibody responses were detected following DNA vaccination with the N-terminal domain of SERA, suggesting that the N-terminal domain alone is not highly immunogenic by this route of vaccine delivery. Immunization of mice by Gene Gun delivery of the 47-kDa domain of SERA elicited a significantly higher serum antibody titer to the antigen than immunization of mice by i.m. injection with the same plasmid did. The predominant isotype subclass of the antibodies elicited to the SERA protein following i.m. and Gene Gun immunizations with SERA plasmid DNA was immunoglobulin G1. Coimmunization of mice with SERA plasmid DNA and a plasmid expressing the hepatitis B surface antigen (pCMV-s) by the i.m. route resulted in higher anti-SERA titers than those generated in mice immunized with the SERA DNA plasmid alone. Vaccination with DNA may provide a viable alternative or may be used in conjunction with protein-based subunit vaccines to maximize the efficacy of a human malaria vaccine that includes immunogenic regions of the SERA protein. PMID:10496891

  6. Immune responses elicited by Mycoplasma hyopneumoniae recombinant antigens and DNA constructs with potential for use in vaccination against porcine enzootic pneumonia.

    Science.gov (United States)

    Virginio, Veridiana Gomes; Gonchoroski, Taylor; Paes, Jéssica Andrade; Schuck, Desirée Cigaran; Zaha, Arnaldo; Ferreira, Henrique Bunselmeyer

    2014-10-01

    Mycoplasma hyopneumoniae is the etiological agent of porcine enzootic pneumonia (PEP) and causes major economic losses to the pig industry worldwide. Commercially available vaccines provide only partial protection and are relatively expensive. In this study, we assessed the humoral and cellular immune responses to three recombinant antigens of M. hyopneumoniae. Immune responses to selected domains of the P46, HSP70 and MnuA antigens (P46102-253, HSP70212-601 and MnuA182-378), delivered as recombinant subunit or DNA vaccines, were evaluated in BALB/c mice. All purified recombinant antigens and two DNA vaccines, pcDNA3.1(+)/HSP70212-601 and pcDNA3.1(+)/MnuA182-378, elicited a strong humoral immune response, indicated by high IgG levels in the serum. The cellular immune response was assessed by detection of IFN-γ, IL-10 and IL-4 in splenocyte culture supernatants. The recombinant subunit and DNA vaccines induced Th1-polarized immune responses, as evidenced by increased levels of IFN-γ. All recombinant subunit vaccines and the pcDNA3.1(+)/MnuA182-378 vaccine also induced the secretion of IL-10, a Th2-type cytokine, in large quantities. The mixed Th1/Th2-type response may elicit an effective immune response against M. hyopneumoniae, suggesting that P46102-253, HSP70212-601 and MnuA182-378 are potential novel and promising targets for the development of vaccines against PEP. PMID:25148775

  7. Identification of protective pneumococcal T(H17 antigens from the soluble fraction of a killed whole cell vaccine.

    Directory of Open Access Journals (Sweden)

    Kristin L Moffitt

    Full Text Available Mucosal or parenteral immunization with a killed unencapsulated pneumococcal whole cell antigen (WCA with an adjuvant protects mice from colonization by a T(H17 CD4+ cell-mediated mechanism. Using preparative SDS gels, we separated the soluble proteins that compose the WCA in order to identify fractions that were immunogenic and protective. We screened these fractions for their ability to stimulate IL-17A secretion from splenocytes obtained from mice immunized with WCA and adjuvant. We identified 12 proteins within the stimulatory fractions by mass spectrometry; these proteins were then cloned, recombinantly expressed and purified using an Escherichia coli expression system. The ability of these proteins to induce IL-17A secretion was then evaluated by stimulation of mouse splenocytes. Of the four most stimulatory proteins, three were protective in a mouse pneumococcal serotype 6B colonization model. This work thus describes a method for identifying immunogenic proteins from the soluble fraction of pneumococcus and shows that several of the proteins identified protect mice from colonization when used as mucosal vaccines. We propose that, by providing protection against pneumococcal colonization, one or more of these proteins may serve as components of a multivalent pneumococcal vaccine.

  8. Tomato bushy stunt virus (TBSV), a versatile platform for polyvalent display of antigenic epitopes and vaccine design

    International Nuclear Information System (INIS)

    Viruses-like particles (VLPs) are frequently being used as platforms for polyvalent display of foreign epitopes of interest on their capsid surface to improve their presentation enhancing the antigenicity and host immune response. In the present study, we used the VLPs of Tomato bushy stunt virus (TBSV), an icosahedral plant virus, as a platform to display 180 copies of 16 amino acid epitopes of ricin toxin fused to the C-terminal end of a modified TBSV capsid protein (NΔ52). Expression of the chimeric recombinant protein in insect cells resulted in spontaneous assembly of VLPs displaying the ricin epitope. Cryo-electron microscopy and image reconstruction of the chimeric VLPs at 22 A resolution revealed the locations and orientation of the ricin epitope exposed on the TBSV capsid surface. Furthermore, injection of chimeric VLPs into mice generated antisera that detected the native ricin toxin. The ease of fusing of short peptides of 15-20 residues and their ability to form two kinds (T = 1, T = 3) of bio-nanoparticles that result in the display of 60 or 180 copies of less constrained and highly exposed antigenic epitopes makes TBSV an attractive and versatile display platform for vaccine design.

  9. The role of Plasmodium falciparum variant surface antigens in protective immunity and vaccine development

    DEFF Research Database (Denmark)

    Hviid, Lars

    2010-01-01

    There is substantial immuno-epidemiological evidence that the parasite-encoded, so-called variant surface antigens (VSAs) such as PfEMP1 on the surface of infected erythrocytes (IEs) are important-in some cases probably decisive-determinants of clinical outcome of P. falciparum malaria. The evide...

  10. Mapping of Antigenic Sites on a SAT2 Foot-and-Mouth Disease Virus Vaccine Strain

    Science.gov (United States)

    Foot-and-mouth disease virus (FMDV) exist as seven serologically distinct serotypes based on the absence of cross-protection following infection. Even within a serotype, distinct genetic and antigenic variants are present, a likely consequence of the high mutation rate of the virus, giving rise to t...

  11. Enhancement of the priming efficacy of DNA vaccines encoding dendritic cell-targeted antigens by synergistic toll-like receptor ligands

    Directory of Open Access Journals (Sweden)

    Kornbluth Richard S

    2009-08-01

    Full Text Available Abstract Background Targeting of protein antigens to dendritic cells (DC via the DEC205 receptor enhances presentation of antigen-derived peptides on MHC-I and MHC-II molecules and, in the presence of costimulatory signals, antigen-specific immune responses. The immunogenicity and efficacy of DNA vaccination can also be enhanced by fusing the encoded antigen to single chain antibodies directed against DEC205. To further improve this strategy, we evaluated different toll-like receptor ligands (TLR and CD40 ligands (CD40L as adjuvants for DNA vaccines encoding a DEC205-single-chain antibody fused to the ovalbumin model antigen or HIV-1 Gag and assessed the priming efficacy of DNA in a DNA prime adenoviral vector boost immunization regimen. Results Mice were primed with the adjuvanted DEC-205 targeted DNA vaccines and boosted with adenoviral vectors encoding the same antigens. CD8+ T cell responses were determined after the adenoviral booster immunization, to determine how well the different DNA immunization regimens prime for the adenoviral boost. In the absence of adjuvants, targeting of DNA-encoded ovalbumin to DCs suppressed CD8+ T-cell responses after the adenoviral booster immunization. CD8+ T-cell responses to the DEC205 targeted DNA vaccines increased only slightly by adding either the TLR-9 ligand CpG, the TLR-3 ligand Poly I:C, or CD40 ligand expression plasmids. However, the combination of both TLR-ligands led to a strong enhancement of CD8+ T-cell responses compared to a non-targeted DNA vaccine. This finding was confirmed using HIV Gag as antigen. Conclusion Although DNA prime adenoviral vector boost immunizations belong to the strongest inducers of cytotoxic T cell responses in different animal models and humans, the CD8+ T cell responses can be further improved by targeting the DNA encoded antigen to DEC205 in the presence of synergistic TLR ligands CpG and Poly I:C.

  12. Vaccination to conserved influenza antigens in mice using a novel Simian adenovirus vector, PanAd3, derived from the bonobo Pan paniscus.

    Science.gov (United States)

    Vitelli, Alessandra; Quirion, Mary R; Lo, Chia-Yun; Misplon, Julia A; Grabowska, Agnieszka K; Pierantoni, Angiolo; Ammendola, Virginia; Price, Graeme E; Soboleski, Mark R; Cortese, Riccardo; Colloca, Stefano; Nicosia, Alfredo; Epstein, Suzanne L

    2013-01-01

    Among approximately 1000 adenoviruses from chimpanzees and bonobos studied recently, the Pan Adenovirus type 3 (PanAd3, isolated from a bonobo, Pan paniscus) has one of the best profiles for a vaccine vector, combining potent transgene immunogenicity with minimal pre-existing immunity in the human population. In this study, we inserted into a replication defective PanAd3 a transgene expressing a fusion protein of conserved influenza antigens nucleoprotein (NP) and matrix 1 (M1). We then studied antibody and T cell responses as well as protection from challenge infection in a mouse model. A single intranasal administration of PanAd3-NPM1 vaccine induced strong antibody and T cell responses, and protected against high dose lethal influenza virus challenge. Thus PanAd3 is a promising candidate vector for vaccines, including universal influenza vaccines. PMID:23536756

  13. Vaccination to conserved influenza antigens in mice using a novel Simian adenovirus vector, PanAd3, derived from the bonobo Pan paniscus.

    Directory of Open Access Journals (Sweden)

    Alessandra Vitelli

    Full Text Available Among approximately 1000 adenoviruses from chimpanzees and bonobos studied recently, the Pan Adenovirus type 3 (PanAd3, isolated from a bonobo, Pan paniscus has one of the best profiles for a vaccine vector, combining potent transgene immunogenicity with minimal pre-existing immunity in the human population. In this study, we inserted into a replication defective PanAd3 a transgene expressing a fusion protein of conserved influenza antigens nucleoprotein (NP and matrix 1 (M1. We then studied antibody and T cell responses as well as protection from challenge infection in a mouse model. A single intranasal administration of PanAd3-NPM1 vaccine induced strong antibody and T cell responses, and protected against high dose lethal influenza virus challenge. Thus PanAd3 is a promising candidate vector for vaccines, including universal influenza vaccines.

  14. Advances in the development of next-generation anthrax vaccines.

    Science.gov (United States)

    Friedlander, Arthur M; Little, Stephen F

    2009-11-01

    Anthrax, a disease of herbivores, only rarely infects humans. However, the threat of using Bacillus anthracis, the causative agent, to intentionally produce disease has been the impetus for development of next-generation vaccines. Two licensed vaccines have been available for human use for several decades. These are composed of acellular culture supernatants containing the protective antigen (PA) component of the anthrax toxins. In this review we summarize the various approaches used to develop improved vaccines. These efforts have included the use of PA with newer adjuvants and delivery systems, including bacterial and viral vectors and DNA vaccines. Attempts to broaden the protection afforded by PA-based vaccines have focused on adding other B. anthracis components, including spore and capsule antigens. PMID:19837282

  15. Immune responses induced by a Leishmania (Leishmania amazonensis recombinant antigen in mice and lymphocytes from vaccinated subjects

    Directory of Open Access Journals (Sweden)

    Ana Paula FERNANDES

    1997-03-01

    Full Text Available In the search for Leishmania recombinant antigens that can be used as a vaccine against American Cutaneous Leishmaniasis, we identified a Leishmania (Leishmania amazonensis recombinant protein of 33 kD (Larp33 which is recognized by antibodies and peripheral blood leukocytes (PBL from subjects vaccinated with Leishvacin ®, Larp33 was expressed in Escherichia coli after cloning of a 2,2 kb Sau3A digested genomic fragment of L. (L. amazonensis into the pDS56-6 His vector. Immunoblotting analysis indicated that Larp33 corresponds to an approximately 40-kD native protein expressed in promastigotes of L.(L. amazonensis and L. (Viannia braziliensis. Northern blots of total RNA also demonstrated that the gene coding for this protein is expressed in promastigotes of the major lineages of Leishmania causing American Cutaneous Leishmaniasis. Larp33 induced partial protection in susceptible mouse strains (BALB/c and C57BL/10 against L. (L. amazonensis after vaccination using Bacille Calmette-Guerin (BCG as adjuvant. In vitro stimulation of splenocytes from BALB/c protected mice with Larp33 elicited the secretion of IL-2 and IFN-g, suggesting that a Th1 cell-mediated protective response is associated with the resistance observed in these mice. As revealed by its immunogenic and antigenic properties, this novel recombinant antigen is a suitable candidate to compose a vaccine against cutaneous leishmaniasisA resposta imune induzida por uma proteína recombinante de Leishmania (Leishmania amazonensis de 33 kD (Larp33 foi avaliada em linfócitos de indivíduos vacinados com a Leishvacin® e em camundongos através de vacinação. Larp33 foi expressa em Escherichia coli após clonagem de um fragmento genômico de L. (L. amazonensis de 2,2 kb no vetor pDS56-6His. Larp33 foi reconhecida por anticorpos IgG presentes no soro de indivíduos vacinados com Leishvacin® e induziu proliferação em linfócitos desses indivíduos em níveis comparáveis ao ant

  16. EXPRESSION OF BACILLUS ANTHRACIS PROTECTIVE ANTIGEN IN VACCINE STRAIN BRUCELLA ABORTUS RB51

    OpenAIRE

    Poff, Sherry Ann

    1997-01-01

    Bacillus anthracis is a facultative intracellular bacterial pathogen that can cause cutaneous, gastrointestinal or respiratory disease in many vertebrates, including humans. Commercially available anthrax vaccines for immunization of humans are of limited duration and do not protect against the respiratory form of the disease. Brucella abortus is a facultative intracellular bacterium that causes chronic infection in animals and humans. As with other intracellular pathogens, cell mediated im...

  17. [Immune response in adult immunized with adsorbed DT-M anatoxin with reduced antigen content and Imovax-DT-adulte vaccine].

    Science.gov (United States)

    Moskalenko, E P; Kharseeva, G G; Sylka, O I; Fedoruk, S I

    2003-01-01

    The comparative study of immune response after immunization of adults with adsorbed DT toxoid with reduced antigen content and Imovax-DT-adulte vaccine, as well as the safety of these preparations, was made. The study revealed that immunization of adults with adsorbed DT toxoid having reduced antigen content, made in two injections, and the injection of Imovax-DT-dulte vaccine, as well as the successive injection of these preparations, produced the same the levels of antitetanus immunity. Antidiphtheria immunity, evaluated by the number of seroconverted to diphtheria persons following two injections immunization was similar for the two preparations, while the level of antidiphtheria antibodies was higher in persons immunized with adsorbed DT toxoid. The immune stratum index was rather high among persons aged 16-29 years. This age group exhibited the highest number of persons, seropositive to both diphtheria and tetanus. Both vaccine preparations, adsorbed DT toxoid with reduced antigen content and Imovax-DT-adulte vaccine, were found to be equally capable of inducing autoimmune reactions in the vaccinees, detected by laboratory methods. PMID:12630352

  18. Antigenicity and diagnostic potential of vaccine candidates in human Chagas disease.

    Directory of Open Access Journals (Sweden)

    Shivali Gupta

    Full Text Available BACKGROUND: Chagas disease, caused by Trypanosoma cruzi, is endemic in Latin America and an emerging infectious disease in the US and Europe. We have shown TcG1, TcG2, and TcG4 antigens elicit protective immunity to T. cruzi in mice and dogs. Herein, we investigated antigenicity of the recombinant proteins in humans to determine their potential utility for the development of next generation diagnostics for screening of T. cruzi infection and Chagas disease. METHODS AND RESULTS: Sera samples from inhabitants of the endemic areas of Argentina-Bolivia and Mexico-Guatemala were analyzed in 1(st-phase for anti-T. cruzi antibody response by traditional serology tests; and in 2(nd-phase for antibody response to the recombinant antigens (individually or mixed by an ELISA. We noted similar antibody response to candidate antigens in sera samples from inhabitants of Argentina and Mexico (n=175. The IgG antibodies to TcG1, TcG2, and TcG4 (individually and TcG(mix were present in 62-71%, 65-78% and 72-82%, and 89-93% of the subjects, respectively, identified to be seropositive by traditional serology. Recombinant TcG1- (93.6%, TcG2- (96%, TcG4- (94.6% and TcG(mix- (98% based ELISA exhibited significantly higher specificity compared to that noted for T. cruzi trypomastigote-based ELISA (77.8% in diagnosing T. cruzi-infection and avoiding cross-reactivity to Leishmania spp. No significant correlation was noted in the sera levels of antibody response and clinical severity of Chagas disease in seropositive subjects. CONCLUSIONS: Three candidate antigens were recognized by antibody response in chagasic patients from two distinct study sites and expressed in diverse strains of the circulating parasites. A multiplex ELISA detecting antibody response to three antigens was highly sensitive and specific in diagnosing T. cruzi infection in humans, suggesting that a diagnostic kit based on TcG1, TcG2 and TcG4 recombinant proteins will be useful in diverse situations.

  19. A Heterologous DNA Prime-Venezuelan Equine Encephalitis Virus Replicon Particle Boost Dengue Vaccine Regimen Affords Complete Protection from Virus Challenge in Cynomolgus Macaques▿

    OpenAIRE

    Chen, Lan; Ewing, Dan; Subramanian, Hemavathy; Block, Karla; Rayner, Jonathan; Alterson, Kimberly D.; Sedegah, Martha; Hayes, Curtis; Porter, Kevin; Raviprakash, Kanakatte

    2007-01-01

    A candidate vaccine (D1ME-VRP) expressing dengue virus type 1 premembrane and envelope proteins in a Venezuelan equine encephalitis (VEE) virus replicon particle (VRP) system was constructed and tested in conjunction with a plasmid DNA vaccine (D1ME-DNA) expressing identical dengue virus sequences. Cynomolgus macaques were vaccinated with three doses of DNA (DDD), three doses of VRP (VVV group), or a heterologous DNA prime-VRP boost regimen (DDV) using two doses of DNA vaccine and a third dos...

  20. Vaccination with Brucella abortus recombinant in vivo-induced antigens reduces bacterial load and promotes clearance in a mouse model for infection.

    Directory of Open Access Journals (Sweden)

    Jake E Lowry

    Full Text Available Current vaccines used for the prevention of brucellosis are ineffective in inducing protective immunity in animals that are chronically infected with Brucella abortus, such as elk. Using a gene discovery approach, in vivo-induced antigen technology (IVIAT on B. abortus, we previously identified ten loci that encode products up-regulated during infection in elk and consequently may play a role in virulence. In our present study, five of the loci (D15, 0187, VirJ, Mdh, AfuA were selected for further characterization and compared with three additional antigens with virulence potential (Hia, PrpA, MltA. All eight genes were PCR-amplified from B. abortus and cloned into E. coli. The recombinant products were then expressed, purified, adjuvanted, and delivered subcutaneously to BALB/c mice. After primary immunization and two boosts, mice were challenged i.p. with 5 x 10⁴ CFU of B. abortus strain 19. Spleens from challenged animals were harvested and bacterial loads determined by colony count at various time points. While vaccination with four of the eight individual proteins appeared to have some effect on clearance kinetics, mice vaccinated with recombinant Mdh displayed the most significant reduction in bacterial colonization. Furthermore, mice immunized with Mdh maintained higher levels of IFN-γ in spleens compared to other treatment groups. Collectively, our in vivo data gathered from the S19 murine colonization model suggest that vaccination with at least three of the IVIAT antigens conferred an enhanced ability of the host to respond to infection, reinforcing the utility of this methodology for the identification of potential vaccine candidates against brucellosis. Mechanisms for immunity to one protein, Mdh, require further in vitro exploration and evaluation against wild-type B. abortus challenge in mice, as well as other hosts. Additional studies are being undertaken to clarify the role of Mdh and other IVI antigens in B. abortus virulence

  1. Vaccination with Brucella abortus recombinant in vivo-induced antigens reduces bacterial load and promotes clearance in a mouse model for infection.

    Science.gov (United States)

    Lowry, Jake E; Isaak, Dale D; Leonhardt, Jack A; Vernati, Giulia; Pate, Jessie C; Andrews, Gerard P

    2011-01-01

    Current vaccines used for the prevention of brucellosis are ineffective in inducing protective immunity in animals that are chronically infected with Brucella abortus, such as elk. Using a gene discovery approach, in vivo-induced antigen technology (IVIAT) on B. abortus, we previously identified ten loci that encode products up-regulated during infection in elk and consequently may play a role in virulence. In our present study, five of the loci (D15, 0187, VirJ, Mdh, AfuA) were selected for further characterization and compared with three additional antigens with virulence potential (Hia, PrpA, MltA). All eight genes were PCR-amplified from B. abortus and cloned into E. coli. The recombinant products were then expressed, purified, adjuvanted, and delivered subcutaneously to BALB/c mice. After primary immunization and two boosts, mice were challenged i.p. with 5 x 10⁴ CFU of B. abortus strain 19. Spleens from challenged animals were harvested and bacterial loads determined by colony count at various time points. While vaccination with four of the eight individual proteins appeared to have some effect on clearance kinetics, mice vaccinated with recombinant Mdh displayed the most significant reduction in bacterial colonization. Furthermore, mice immunized with Mdh maintained higher levels of IFN-γ in spleens compared to other treatment groups. Collectively, our in vivo data gathered from the S19 murine colonization model suggest that vaccination with at least three of the IVIAT antigens conferred an enhanced ability of the host to respond to infection, reinforcing the utility of this methodology for the identification of potential vaccine candidates against brucellosis. Mechanisms for immunity to one protein, Mdh, require further in vitro exploration and evaluation against wild-type B. abortus challenge in mice, as well as other hosts. Additional studies are being undertaken to clarify the role of Mdh and other IVI antigens in B. abortus virulence and induction of

  2. Monitoring antigenic protein integrity during glycoconjugate vaccine synthesis using capillary electrophoresis-mass spectrometry.

    Science.gov (United States)

    Tengattini, Sara; Domínguez-Vega, Elena; Temporini, Caterina; Terreni, Marco; Somsen, Govert W

    2016-09-01

    A capillary electrophoresis-mass spectrometry (CE-MS) method was developed for the characterization and integrity assessment of the Mycobacterium tuberculosis (MTB) antigens TB10.4 and Ag85B and their chemically produced glycoconjugates, which are glycovaccine candidates against tuberculosis (TB). In order to prevent protein adsorption to the inner capillary wall and to achieve efficient separation of the antigen proteoforms, a polyionic multilayer coating of polybrene-dextran sulfate-polybrene (PB-DS-PB) was used in combination with 1.5 M acetic acid as background electrolyte (BGE). Coupling of CE to high-resolution time-of-flight MS was achieved by a coaxial interface employing a sheath liquid of isopropanol-water (50:50, v/v) containing 0.1 % formic acid. The MTB antigens were exposed to experimental conditions used for chemical glycosylation (but no activated saccharide was added) in order to investigate their stability during glycovaccine production. CE-MS analysis revealed the presence of several closely related degradation products, including truncated, oxidized and conformational variants, which were assigned by accurate mass. Analysis of synthesized mannose conjugates of TB10.4 and Ag85B allowed the determination of the glycoform composition of the neo-glycoproteins next to the characterization of degradation products which were shown to be partly glycoconjugated. Moreover, the selectivity of CE-MS allowed specific detection of deamidated species (protein mass change of 1.0 Da only), indicating that chemical glycosylation increased susceptibility to deamidation. Overall, the results show that CE-MS represents a useful analytical tool for the detailed characterization and optimization of neo-glycoconjugate products. Graphical Abstract Flowchart illustrating Mycobacterium tuberculosis (MTB) antigen glycosylation, glycoconjugate variant and degradation product separation by capillary electrophoresis (CE) and their characterization by intact mass

  3. Α1-giardin based live heterologous vaccine protects against Giardia lamblia infection in a murine model.

    Science.gov (United States)

    Jenikova, Gabriela; Hruz, Petr; Andersson, Mattias K; Tejman-Yarden, Noa; Ferreira, Patricia C D; Andersen, Yolanda S; Davids, Barbara J; Gillin, Frances D; Svärd, Staffan G; Curtiss, Roy; Eckmann, Lars

    2011-11-28

    Giardia lamblia is a leading protozoan cause of diarrheal disease worldwide, yet preventive medical strategies are not available. A crude veterinary vaccine has been licensed for cats and dogs, but no defined human vaccine is available. We tested the vaccine potential of three conserved antigens previously identified in human and murine giardiasis, α1-giardin, α-enolase, and ornithine carbamoyl transferase, in a murine model of G. lamblia infection. Live recombinant attenuated Salmonella enterica Serovar Typhimurium vaccine strains were constructed that stably expressed each antigen, maintained colonization capacity, and sustained total attenuation in the host. Oral administration of the vaccine strains induced antigen-specific serum IgG, particularly IgG(2A), and mucosal IgA for α1-giardin and α-enolase, but not for ornithine carbamoyl transferase. Immunization with the α1-giardin vaccine induced significant protection against subsequent G. lamblia challenge, which was further enhanced by boosting with cholera toxin or sublingual α1-giardin administration. The α-enolase vaccine afforded no protection. Analysis of α1-giardin from divergent assemblage A and B isolates of G. lamblia revealed >97% amino acid sequence conservation and immunological cross-reactivity, further supporting the potential utility of this antigen in vaccine development. Together. These results indicate that α1-giardin is a suitable candidate antigen for a vaccine against giardiasis. PMID:22001876

  4. Vaccination of grazing calves with antigens from the intestinal membranes of Haemonchus contortus: effects against natural challenge with Haemonchus placei and Haemonchus similis.

    Science.gov (United States)

    Bassetto, C C; Silva, M R L; Newlands, G F J; Smith, W D; Ratti Júnior, J; Martins, C L; Amarante, A F T

    2014-09-01

    A vaccine containing integral membrane glycoproteins from the intestine of Haemonchus contortus was evaluated in three groups of eight 5 months old grazing calves, naturally infected by Haemonchus similis, Haemonchus placei and other gastrointestinal nematodes. Vaccinated calves received 5 or 50μg of the antigen and 1mg of saponin adjuvant, while the controls received adjuvant alone, initially three times, 3 weeks apart and then four more times at 6 weeks intervals. Three weeks after the last immunisation all of the calves were euthanised for worm counts. Immunisation stimulated high titre antibodies against the vaccine antigens, reduced the egg output of Haemonchus spp. by 85% and the numbers of H. placei and H. similis by 63% and 32%, respectively, compared with control calves. It was concluded that vaccination with intestinal membrane glycoproteins from H. contortus could substantially reduce the transmission of H. placei and H. similis, thus providing protective benefit downstream. This appears to be the first known successful demonstration of a vaccine protective for cattle naturally exposed to infection with any gastrointestinal nematode parasite. PMID:24960373

  5. A Modular Vaccine Development Platform Based on Sortase-Mediated Site-Specific Tagging of Antigens onto Virus-Like Particles.

    Science.gov (United States)

    Tang, Shubing; Xuan, Baoqin; Ye, Xiaohua; Huang, Zhong; Qian, Zhikang

    2016-01-01

    Virus-like particles (VLPs) can be used as powerful nanoscale weapons to fight against virus infection. In addition to direct use as vaccines, VLPs have been extensively exploited as platforms on which to display foreign antigens for prophylactic vaccination and immunotherapeutic treatment. Unfortunately, fabrication of new chimeric VLP vaccines in a versatile, site-specific and highly efficient manner is beyond the capability of traditional VLP vaccine design approaches, genetic insertion and chemical conjugation. In this study, we described a greatly improved VLP display strategy by chemoenzymatic site-specific tailoring antigens on VLPs surface with high efficiency. Through the transpeptidation mediated by sortase A, one protein and two epitopes containing N-terminal oligoglycine were conjugated to the LPET motif on the surface of hepatitis B virus core protein (HBc) VLPs with high density. All of the new chimeric VLPs induced strong specific IgG responses. Furthermore, the chimeric VLPs with sortase A tagged enterovirus 71 (EV71) SP70 epitope could elicit effective antibodies against EV71 lethal challenging as well as the genetic insertion chimeric VLPs. The sortase A mediated chemoenzymatic site-specific tailoring of the HBc VLP approach shows great potential in new VLP vaccine design for its simplicity, site specificity, high efficiency, and versatility. PMID:27170066

  6. Analysis of antigenic variation in equine 2 influenza A viruses.

    Science.gov (United States)

    Hinshaw, V S; Naeve, C W; Webster, R G; Douglas, A; Skehel, J J; Bryans, J

    1983-01-01

    Influenza outbreaks involving viruses of the H3N8 subtype (equine 2) often occur in vaccinated horses. For this reason, a series of influenza viruses of the H3N8 subtype were examined to determine if antigenic variation could be detected in isolates during the period 1963-81. Antigenic analyses with post-infection ferret sera and monoclonal antibodies showed that the haemagglutinins of recent isolates were antigenically distinguishable from the prototype A/eq/Miami/1/63 and that antigenically distinguishable groups of equine 2 viruses co-circulate in the horse population. Based on these studies, it is recommended that a recent equine strain, A/equine/Fontainebleu/1/79 or A/equine/Kentucky/1/81, serve as an additional prototype strain for this subtype.Antigenic variation in equine 2 viruses may be of epidemiological significance, yet the overall conservation of these strains makes it unlikely that vaccine failures can be attributed solely to antigenic changes in these viruses. A sufficiently potent vaccine, containing a current representative of the most prevalent equine 2 strain, may improve the protection afforded by equine vaccines. PMID:6601538

  7. Effects of pre-existing anti-carrier immunity and antigenic element multiplicity on efficacy of a modular virus-like particle vaccine.

    Science.gov (United States)

    Chuan, Yap P; Rivera-Hernandez, Tania; Wibowo, Nani; Connors, Natalie K; Wu, Yang; Hughes, Fiona K; Lua, Linda H L; Middelberg, Anton P J

    2013-09-01

    Modularization of a peptide antigen for presentation on a microbially synthesized murine polyomavirus (MuPyV) virus-like particle (VLP) offers a new alternative for rapid and low-cost vaccine delivery at a global scale. In this approach, heterologous modules containing peptide antigenic elements are fused to and displayed on the VLP carrier, allowing enhancement of peptide immunogenicity via ordered and densely repeated presentation of the modules. This study addresses two key engineering questions pertaining to this platform, exploring the effects of (i) pre-existing carrier-specific immunity on modular VLP vaccine effectiveness and (ii) increase in the antigenic element number per VLP on peptide-specific immune response. These effects were studied in a mouse model and with modular MuPyV VLPs presenting a group A streptococcus (GAS) peptide antigen, J8i. The data presented here demonstrate that immunization with a modular VLP could induce high levels of J8i-specific antibodies despite a strong pre-existing anti-carrier immune response. Doubling of the J8i antigenic element number per VLP did not enhance J8i immunogenicity at a constant peptide dose. However, the strategy, when used in conjunction with increased VLP dose, could effectively increase the peptide dose up to 10-fold, leading to a significantly higher J8i-specific antibody titer. This study further supports feasibility of the MuPyV modular VLP vaccine platform by showing that, in the absence of adjuvant, modularized GAS antigenic peptide at a dose as low as 150 ng was sufficient to raise a high level of peptide-specific IgGs indicative of bactericidal activity. PMID:23532896

  8. Immune Responses Induced by Gene Gun or Intramuscular Injection of DNA Vaccines That Express Immunogenic Regions of the Serine Repeat Antigen from Plasmodium falciparum

    OpenAIRE

    Belperron, Alexia A.; Feltquate, David; Fox, Barbara A.; Horii, Toshihiro; Bzik, David J.

    1999-01-01

    The liver- and blood-stage-expressed serine repeat antigen (SERA) of Plasmodium falciparum is a candidate protein for a human malaria vaccine. We compared the immune responses induced in mice immunized with SERA-expressing plasmid DNA vaccines delivered by intramuscular (i.m.) injection or delivered intradermally by Gene Gun immunization. Mice were immunized with a pcdna3 plasmid encoding the entire 47-kDa domain of SERA (amino acids 17 to 382) or the N-terminal domain (amino acids 17 to 110)...

  9. Enhanced Protective Efficacy of a Chimeric Form of the Schistosomiasis Vaccine Antigen Sm-TSP-2

    OpenAIRE

    Pearson, Mark S.; Pickering, Darren A.; McSorley, Henry J.; Bethony, Jeffrey M; Tribolet, Leon; Dougall, Annette M.; Hotez, Peter J.; Loukas, Alex

    2012-01-01

    The large extracellular loop of the Schistosoma mansoni tetraspanin, Sm-TSP-2, when fused to a thioredoxin partner and formulated with Freund's adjuvants, has been shown to be an efficacious vaccine against murine schistosomiasis. Moreover, Sm-TSP-2 is uniquely recognised by IgG1 and IgG3 from putatively resistant individuals resident in S. mansoni endemic areas in Brazil. In the present study, we expressed Sm-TSP-2 at high yield and in soluble form in E. coli without the need for a solubilit...

  10. Cloning and vaccination properties of the sporozoite antigen Eimeria stiedae (rabbit coccidiosis)

    International Nuclear Information System (INIS)

    Coccidiosis, caused by the protozoan parasite of the genus Eimeria, is a common disease in rabbits and chicken and is of the major economic importance to poultry industry and commercial rabbit's production around the world. Ten known Eimeria species infects the rabbits. Nine of them infect only the intestinal tract while one (Eimeria stiedae) infects the intrahepathic epithelial bile ducts. At present, coccidiosis is controlled by chemotherapy. However, the emergence of drug resistant parasites coupled with the higher cost for developing new coccidiostats has drawn the attention to alternative means of control such as immunoprophylaxis including the development of genetically engineered vaccines

  11. Ad Hoc Influenza Vaccination During Years of Significant Antigenic Drift in a Tropical City With 2 Seasonal Peaks: A Cross-Sectional Survey Among Health Care Practitioners.

    Science.gov (United States)

    Wong, Martin C S; Nelson, E Anthony S; Leung, Czarina; Lee, Nelson; Chan, Martin C W; Choi, Kin Wing; Rainer, Timothy H; Cheng, Frankie W T; Wong, Samuel Y S; Lai, Christopher K C; Lam, Bosco; Cheung, Tak Hong; Leung, Ting Fan; Chan, Paul K S

    2016-05-01

    We evaluated the acceptability of an additional ad hoc influenza vaccination among the health care professionals following seasons with significant antigenic drift.Self-administered, anonymous surveys were performed by hard copy questionnaires in public hospitals, and by an on-line platform available to all healthcare professionals, from April 1st to May 31st, 2015. A total of 1290 healthcare professionals completed the questionnaires, including doctors, nurses, and allied health professionals working in both the public and private systems.Only 31.8% of participating respondents expressed an intention to receive the additional vaccine, despite that the majority of them agreed or strongly agreed that it would bring benefit to the community (88.9%), save lives (86.7%), reduce medical expenses (76.3%), satisfy public expectation (82.8%), and increase awareness of vaccination (86.1%). However, a significant proportion expressed concern that the vaccine could disturb the normal immunization schedule (45.5%); felt uncertain what to do in the next vaccination round (66.0%); perceived that the summer peak might not occur (48.2%); and believed that the summer peak might not be of the same virus (83.5%). Furthermore, 27.8% of all respondents expected that the additional vaccination could weaken the efficacy of previous vaccinations; 51.3% was concerned about side effects; and 61.3% estimated that there would be a low uptake rate. If the supply of vaccine was limited, higher priority groups were considered to include the elderly aged ≥65 years with chronic medical conditions (89.2%), the elderly living in residential care homes (87.4%), and long-stay residents of institutions for the disabled (80.7%). The strongest factors associated with accepting the additional vaccine included immunization with influenza vaccines in the past 3 years, higher perceived risk of contracting influenza, and higher perceived severity of the disease impact.The acceptability to an additional ad

  12. Nanolipoprotein Particles (NLPs) as Versatile Vaccine Platforms for Co-delivery of Multiple Adjuvants with Subunit Antigens from Burkholderia spp. and F. tularensis - Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, N. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-06

    The goal of this proposal is to demonstrate that colocalization of protein subunit antigens and adjuvants on nanolipoprotein particles (NLPs) can increase the protective efficacy of subunit antigens from Burkholderia spp. and Francisella tularensis against an aerosol challenge. In the second quarter of the third year, LLNL finalized all immunological assessments of NLP vaccine formulations in the F344 model. Battelle has immunized rats with three unique NLP formulations by either intramuscular or intranasal administration. All inoculations have been completed, and protective efficacy against an aerosolized challenge will begin at the end of October, 2014.

  13. Recombinant Virus Vaccination against “Self” Antigens Using Anchor-fixed Immunogens

    OpenAIRE

    Irvine, Kari R.; Parkhurst, Maria R.; Shulman, Eliza P.; Tupesis, Janis P; Custer, Mary; Touloukian, Christopher E; Robbins, Paul F.; Yafal, Alicia Gómez; Greenhalgh, Patricia; Sutmuller, Roger P.M.; Offringa, Rienk; Rosenberg, Steven A.; Restifo, Nicholas P

    1999-01-01

    To study the induction of anti-“self” CD8+ T-cell reactivity against the tumor antigen gp100, we used a mouse transgenic for a chimeric HLA-A*0201/H-2 Kb molecule (A2/Kb). We immunized the mice with a recombinant vaccinia virus encoding a form of gp100 that had been modified at position 210 (from a threonine to a methionine) to increase epitope binding to the restricting class I molecule. Immunogens containing the “anchor-fixed” modification elicited anti-self CD8+ T cells specific for the wi...

  14. Pentamers Not Found in the Universal Proteome Can Enhance Antigen Specific Immune Responses and Adjuvant Vaccines

    OpenAIRE

    Ami Patel; Dong, Jessica C.; Brett Trost; Richardson, Jason S.; Sarah Tohme; Shawn Babiuk; Anthony Kusalik; Kung, Sam K. P.; Kobinger, Gary P.

    2012-01-01

    Certain short peptides do not occur in humans and are rare or non-existent in the universal proteome. Antigens that contain rare amino acid sequences are in general highly immunogenic and may activate different arms of the immune system. We first generated a list of rare, semi-common, and common 5-mer peptides using bioinformatics tools to analyze the UniProtKB database. Experimental observations indicated that rare and semi-common 5-mers generated stronger cellular responses in comparison wi...

  15. Serum antibody responses to vaccinal antigens in lean and obese geriatric dogs.

    Science.gov (United States)

    Ellis, John; Gow, Sheryl; Rhodes, Carrie; Lacoste, Stacey; Kong, Lyndsay; Musil, Kristyna; Snead, Elisabeth

    2016-05-01

    The immune responses in control dogs [1 to 4 years of age, body condition score (BCS): 4 to 5 out of 9] were compared to those of aging dogs (based on breed and body size) either categorized as lean (BCS: 4 to 5 out of 9) or obese (BCS: 8 to 9 out of 9). Of interest were the serum titers to the following common agents found in vaccines, canine parainfluenza virus (CPIV), canine parvovirus (CPV), canine distemper virus (CDV), canine respiratory coronavirus (CRCoV), and Bordetella bronchiseptica. There were no statistical differences in the antibodies to CPIV, B. bronchispetica, and CRCoV, among the age/weight categories, nor among the age/weight categories and the time, in days, between the date of sample collection and the date of the last recorded vaccination for CPIV, B. bronchiseptica, CPV, and CDV. For CPV, the control dogs had significantly (P < 0.002) higher serum neutralization (SN) titers than the lean geriatric dogs and the obese geriatric dogs. For CDV SN titers, the only statistically significant (P = 0.01) difference was that the control dogs had higher SN titers than the lean geriatric dogs. PMID:27152043

  16. Antigenic diversity of meningococcal enterobactin receptor FetA, a vaccine component.

    Science.gov (United States)

    Thompson, Emily A L; Feavers, Ian M; Maiden, Martin C J

    2003-07-01

    Meningococcal FetA (FrpB), an iron-regulated outer-membrane protein and vaccine component, was shown to be highly diverse: a total of 60 fetA alleles, encoding 56 protein sequences, were identified from 107 representative Neisseria meningitidis isolates. Phylogenetic analysis established that the allelic variants had been generated by both point mutation and horizontal genetic exchange. Nucleotide substitution was unevenly distributed in the gene, which contained both conserved and variable sequence regions. The most conserved region of the translated peptide sequence corresponded to an amino-terminal domain of the protein and the most diverse region to a previously identified variable region (VR). A nomenclature system for the peptides encoded by the VR was devised which classified 24 variants into 5 FetA variant families. On the basis of these data, murine polyclonal sera specific for four FetA variants were generated. The reactivities of these sera in whole-cell ELISA experiments were consistent with the hypothesis that the VR encoded an immunodominant epitope and indicated that the sera reacted mainly with variants against which they were raised. The diversity of this protein is likely to limit its effectiveness as a vaccine component. PMID:12855736

  17. In vitro evaluation of a soluble Leishmania promastigote surface antigen as a potential vaccine candidate against human leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Rym Chamakh-Ayari

    Full Text Available PSA (Promastigote Surface Antigen belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L. species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm or L. braziliensis (CCLb or visceral leishmaniasis due to L. donovani (CVLd and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection or non immune/naive individuals (HLR: Healthy Low Responders, depending on whether they produce high or low levels of IFN-γ in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-γ, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-α in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-γ after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-γ-producing CD4+ T cells and the released IFN-γ. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection.

  18. Vaccination of Goats with 31 kDa and 32 kDa Schistosoma japonicum Antigens by DNA Priming and Protein Boosting

    Institute of Scientific and Technical Information of China (English)

    Lianfei Tang; Zhijun Zhou; Yuxiao Chen; Yonghui Luo; Linqian Wang; Liyu Chen; Fushen Huang; Xianfang Zeng; Xinyuan Yi

    2007-01-01

    Two Schistosoma japonicum vaccine candidate antigens Sj 31 and Sj 32, which have shown particular promise to induce protective immunity in mice, were used to immunize goats by using a DNA priming-protein boosting strategy in present work. DNA vaccine formulations of the two antigens (VRSj31 and VRSj32) were produced and injected intramuscularly twice at a 2-week interval and then recombinant proteins (rSj31 and rSj32) together with Freund Complete Adjuvant (FCA) were used to boost the goats. The experiment was repeated in different batche cercariae. A strong anamnestic antibody response was induced after boost. A significant reduction of liver egg counts and miracidial hatching was showed in both experiments. Significant protections against challenge infection were elicited with 31.6% of percentage reduction for worm recovery in the second experiment and 20.9% in the first experiment, respectively.

  19. Antigen localization and the induction of resistance in mice vaccinated with irradiated cercariae of Schistosoma mansoni

    International Nuclear Information System (INIS)

    The fate of 75Se-labelled parasites and their released pre-synthesized macromolecules has been followed in three murine infection models. Marked differences were found between the three models. The pattern of migration of normal schistosomula was similar to that previously reported. In addition we have described the transit of parasites through the lymph nodes draining the infection site. Significant quantities of released material were detected in the skin, draining lymph nodes, bloodstream and liver. The circulating material was of parasite origin, macromolecular, and hence potentially antigenic. In comparison to the normal infection, radiation-attenuated parasites (inducing a high level of resistance to challenge) persisted in the skin, draining lymph nodes and lungs, releasing a proportionally greater amount of material in the nodes. In mice exposed to attenuated parasites and treated with the compound RO11-3128 at 24 h (inducing a low level of resistance) there was an early death and rapid clearance of the parasites whilst still in the skin. This situation resulted in the highest levels of released material in the skin, bloodstream and liver, but negligible levels in the draining lymph nodes. We suggest that the persistence of radiation-attenuated parasites in the skin and draining lymph nodes, together with the prolonged release of antigen in the latter site, compared to the normal situation, are major factors in the induction of resistance. (author)

  20. Antigen localization and the induction of resistance in mice vaccinated with irradiated cercariae of Schistosoma mansoni

    Energy Technology Data Exchange (ETDEWEB)

    Mountford, A.P.; Coulson, P.S.; Wilson, R.A.

    1988-08-01

    The fate of /sup 75/Se-labelled parasites and their released pre-synthesized macromolecules has been followed in three murine infection models. Marked differences were found between the three models. The pattern of migration of normal schistosomula was similar to that previously reported. In addition we have described the transit of parasites through the lymph nodes draining the infection site. Significant quantities of released material were detected in the skin, draining lymph nodes, bloodstream and liver. The circulating material was of parasite origin, macromolecular, and hence potentially antigenic. In comparison to the normal infection, radiation-attenuated parasites (inducing a high level of resistance to challenge) persisted in the skin, draining lymph nodes and lungs, releasing a proportionally greater amount of material in the nodes. In mice exposed to attenuated parasites and treated with the compound RO11-3128 at 24 h (inducing a low level of resistance) there was an early death and rapid clearance of the parasites whilst still in the skin. This situation resulted in the highest levels of released material in the skin, bloodstream and liver, but negligible levels in the draining lymph nodes. We suggest that the persistence of radiation-attenuated parasites in the skin and draining lymph nodes, together with the prolonged release of antigen in the latter site, compared to the normal situation, are major factors in the induction of resistance.

  1. Personalized peptide vaccination for advanced biliary tract cancer: IL-6, nutritional status and pre-existing antigen-specific immunity as possible biomarkers for patient prognosis

    OpenAIRE

    Yoshitomi, Munehiro; Yutani, Shigeru; Matsueda, Satoko; IOJI, TETSUYA; Komatsu, Nobukazu; SHICHIJO, SHIGEKI; Yamada, Akira; ITOH, KYOGO; SASADA, TETSURO; Kinoshita, Hisafumi

    2011-01-01

    Considering that the prognosis of patients with advanced biliary tract cancer (BTC) remains very poor, with a median survival of less than 1 year, new therapeutic approaches need to be developed. In the present study, a phase II clinical trial of personalized peptide vaccination (PPV) was conducted in advanced BTC patients to evaluate the feasibility of this treatment and to identify potential biomarkers. A maximum of 4 human leukocyte antigen-matched peptides, which were selected based on th...

  2. Role of Escherichia coli type 1 pilus in colonization of porcine ileum and its protective nature as a vaccine antigen in controlling colibacillosis.

    OpenAIRE

    Jayappa, H G; Goodnow, R. A.; Geary, S. J.

    1985-01-01

    This study was designed to evaluate the role of Escherichia coli type 1 pili in adherence of the organism to porcine small intestines and the efficacy of pili as a vaccine antigen in controlling neonatal colibacillosis. Our results demonstrated that an E. coli phase cloned to express type 1 pili readily attached to the small intestines of colostrum-deprived newborn pigs. Immunofluorescent staining of intestine sections revealed the presence of E. coli expressing type 1 pili only on the brush ...

  3. Molecular characterization of thyroid hormone receptor beta from Schistosoma japonicum and assessment of its potential as a vaccine candidate antigen against schistosomiasis in BALB/c mice

    OpenAIRE

    Qiu Chunhui; Liu Shengfa; Hong Yang; Fu Zhiqiang; Wei Meimei; Ai Dezhou; Lin Jiaojiao

    2012-01-01

    Abstract Background Thyroid hormones (TH) modulate growth, development and differentiation and metabolic processes by interacting with thyroid hormone receptors (THRs). The purpose of this study was to identify a novel thyroid hormone receptor beta encoding gene of Schistosoma japonicum (SjTHRβ) and to investigate its potential as a vaccine candidate antigen against schistosomiasis in BALB/c mice. Methods The full-length cDNA sequence of SjTHRβ, its gene organization, and its transcript level...

  4. Enhancement by ampicillin of antibody responses induced by a protein antigen and a DNA vaccine carried by live-attenuated Salmonella enterica serovar Typhi.

    Science.gov (United States)

    Woo, P C; Tsoi, H W; Leung, H C; Wong, L P; Wong, S S; Chan, E; Yuen, K Y

    2000-07-01

    Live-attenuated Salmonella species are effective carriers of microbial antigens and DNA vaccines. In a mouse model, the immunoglobulin M (IgM) and total antibody levels directed toward the lipopolysaccharide of Salmonella enterica serovar Typhi were significantly enhanced at day 21 after oral immunization with live-attenuated serovar Typhi (strain Ty21a) when ampicillin was concomitantly administered (P Ty21a-stimulated lymphocyte proliferation indices for the ampicillin group at day 21 were significantly higher than those for the normal saline (NS) group (P Ty21a per well, respectively). The 50% lethal doses for mice from the ampicillin and NS groups immunized with Ty21a with pBR322 after wild-type serovar Typhi challenge on day 24 were 3.4 x 10(7) and 5.0 x 10(6) CFU, respectively. The fecal bacterial counts for the ampicillin group at days 1, 3, and 5 were significantly lower than those for the NS group (P Ty21a in a larger number of mice from the ampicillin group than from the NS group. Furthermore, the IgG2a levels directed toward tetanus toxoid were significantly enhanced at days 7 and 21 after oral immunization with Ty21a that carried the fragment c of tetanus toxoid when ampicillin was concomitantly administered (P Ty21a that carried the DNA vaccine that encodes hepatitis B surface antigen when ampicillin was concomitantly administered. The present observation may improve the efficacy of the protein antigens and DNA vaccines carried in live-attenuated bacteria, and further experiments should be carried out to determine the best antibiotics and dosage regimen to be used, as well as the best carrier system for individual protein antigens and DNA vaccines. PMID:10882658

  5. Redefining an epitope of a malaria vaccine candidate, with antibodies against the N-terminal MSA-2 antigen of Plasmodium harboring non-natural peptide bonds

    OpenAIRE

    Lozano, José Manuel; Guerrero, Yuly Andrea; Alba, Martha Patricia; Lesmes, Liliana Patricia; Escobar, José Oswaldo; Patarroyo, Manuel Elkin

    2013-01-01

    The aim of obtaining novel vaccine candidates against malaria and other transmissible diseases can be partly based on selecting non-polymorphic peptides from relevant antigens of pathogens, which have to be then precisely modified for inducing a protective immunity against the disease. Bearing in mind the high degree of the MSA-221–40 peptide primary structure’s genetic conservation among malaria species, and its crucial role in the high RBC binding ability of Plasmodium falciparum (the main ...

  6. Assessing the relationship between antigenicity and immunogenicity of human rabies vaccines when administered by intradermal route: Results of a metaanalysis

    OpenAIRE

    Sudarshan, Mysore Kalappa; Bilagumba, Gangaboraiah; Ravish, Haradanahalli Shankarappa; Narayana, Hanumanthappa Ashwath Doddabele

    2010-01-01

    The metadata of 10 published studies and 3 vaccine trial reports comprising of 19 vaccine cohorts from four countries conducted over a period of 23 years (1986–2009) was used for metaanalysis. The vaccines studied were purified chick embryo cell vaccine (Rabipur, India and Germany), purified vero cell rabies vaccine (Verorab, France; Indirab, India) and human diploid cell vaccine (MIRV, France). The potency of these vaccines varied from 0.55 IU to 2.32 IU per intradermal dose of 0.1 ml per si...

  7. Vaccination focusing immunity on conserved antigens protects mice and ferrets against virulent H1N1 and H5N1 influenza A viruses.

    Science.gov (United States)

    Price, Graeme E; Soboleski, Mark R; Lo, Chia-Yun; Misplon, Julia A; Pappas, Claudia; Houser, Katherine V; Tumpey, Terrence M; Epstein, Suzanne L

    2009-11-01

    Immunization against conserved virus components induces broad, heterosubtypic protection against diverse influenza A viruses, providing a strategy for controlling unexpected outbreaks or pandemics until strain-matched vaccines become available. This study characterized immunization to nucleoprotein (NP) and matrix 2 (M2) by DNA priming followed by parenteral or mucosal boosting in mice and ferrets. DNA vaccination followed by boosting with antigen-matched recombinant adenovirus (rAd) or cold-adapted (ca) influenza virus provided robust protection against virulent H1N1 and H5N1 challenges. Compared to other boosts, mucosal rAd induced stronger IgA responses, more virus-specific activated T-cells in the lung, and better protection against morbidity following challenge even eight months post-boost. In ferrets, both mucosal and parenteral rAd boosting protected from lethal H5N1 challenge. These findings demonstrate potent protection by vaccination highly focused on conserved antigens and identify immune response measures in mice that differed among vaccinations and correlated with outcome. PMID:19729082

  8. Human Leukocyte Antigen Associations with Humoral and Cellular Immunity Following a Second Dose of Measles-Containing Vaccine: Persistence, Dampening, and Extinction of Associations Found After a First Dose

    OpenAIRE

    Jacobson, Robert M.; Ovsyannikova, Inna G.; Vierkant, Robert A.; Pankratz, V. Shane; Poland, Gregory A.

    2011-01-01

    Previously we found Human Leukocyte Antigen (HLA) associations with humoral immunity following a single dose of measles-containing vaccine. In this study, we sought to determine if HLA associations exist with humoral and cellular immunity following a second dose of measles-containing vaccine and if the associations we found with humoral immunity after the first dose persist following a second dose.

  9. Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine.

    Directory of Open Access Journals (Sweden)

    Anne Endmann

    Full Text Available Currently marketed vaccines against hepatitis B virus (HBV based on the small (S hepatitis B surface antigen (HBsAg fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

  10. Immune responses of a chimaeric protein vaccine containing Mycoplasma hyopneumoniae antigens and LTB against experimental M. hyopneumoniae infection in pigs.

    Science.gov (United States)

    Marchioro, Silvana B; Sácristan, Rubén Del Pozo; Michiels, Annelies; Haesebrouck, Freddy; Conceição, Fabricio R; Dellagostin, Odir A; Maes, Dominiek

    2014-08-01

    A recombinant chimaeric protein containing three Mycoplasma hyopneumoniae antigens (C-terminal portion of P97, heat shock protein P42, and NrdF) fused to an adjuvant, the B subunit of heat-labile enterotoxin of Escherichia coli (LTB), was used to immunize pigs against enzootic pneumonia. The systemic and local immune responses, as well as the efficacy of the chimaeric protein in inducing protection against experimental M. hyopneumoniae infection were evaluated. In total, 60 male piglets, purchased from a M. hyopneumoniae-free herd, at 4 weeks of age were randomly allocated to six different experimental groups of 10 animals each: recombinant chimaeric protein by intramuscular (IM) (1) or intranasal (IN) (2) administration, commercial bacterin by IM administration (3), and the adjuvant LTB by IM (4, control group A) or IN (5, control group B) administration. All groups were immunized at 24 and 38 days of age and challenged at 52 days of age. The sixth group that was not challenged was used as the negative control (IN [n=5] or IM [n=5] administration of the LTB adjuvant). Compared with the non-challenged group, administration of the chimaeric protein induced significant (Phyopneumoniae infection in pigs. This lack of effectiveness points towards the need for further studies to improve the efficacy of this subunit-based vaccine approach. PMID:24909331

  11. Immunogenicity and safety of liposome-vaccine encapsulating hepatitis B surface antigen and phosphodiester CpG oligodeoxynucleotides

    Institute of Scientific and Technical Information of China (English)

    CHUN YAN HE; QING LIANG LIU

    2006-01-01

    CpG oligodeoxynucleotides (CpG ODN) as adjuvant have been extensively studied in recent years. Phosphodiester CpG ODN (PO CpG ODN) can perfectly mimic bacterial DNA in enhancing immune response but are vulnerable to nucleases in vivo. This study aimed to evaluate the immunostimu latory potential and safety of phosphodiester CpG ODN encapsulated in nonphospholipid liposomes.BALB/c mice were immunized intramuscularly with different formulations of liposomes, CpG ODN and hepatitis B surface antigen (HBsAg). The results demonstrated that the encapsulated PO CpG ODN were protected against rapid degradation in vivo and retained their adjuvant activity. PO CpG ODN encapsulated with HBsAg in liposomes induced strong Th1-biased or Th1/Th2 mixed humoral immune response in mice with the magnitude similar to their phosphothioate equivalent in the same formulation.High IFN-gamma production induced by this formulation confirmed the generation of strong cellular immune response. Additionally, co-delivery of HBsAg and PO CpG ODN improved the immune response over that obtained with separate delivery. Safety experiment showed that liposome-encapsulaed PO CpG ODN and HBsAg caused mild systemic and moderate local adverse reaction. In conclusion, our data shows that PO CpG ODN encapsulated in liposomes fully exhibit their Th1-type adjuvant activity and act as a potential adjuvant for vaccines.

  12. Impact of pneumococcal vaccination in children on serotype distribution in adult community-acquired pneumonia using the serotype-specific multiplex urinary antigen detection assay.

    Science.gov (United States)

    Pletz, Mathias W; Ewig, Santiago; Rohde, Gernot; Schuette, Hartwig; Rupp, Jan; Welte, Tobias; Suttorp, Norbert; Forstner, Christina

    2016-04-29

    The aim of the study was to compare the distribution of the vaccine-serotypes covered by pneumococcal conjugate vaccines (PCV7 and PCV13) in adult patients with pneumococcal community-acquired pneumonia in Germany between the periods 2002-2006 and 2007-2011 using a novel serotype-specific multiplex urinary antigen detection assay (SSUA). Vaccination of children started with PCV7 in 2007, which was replaced by PCV13 in 2010. Following confirmation of the accuracy of SSUA in long-term stored urine samples from 112 patients with confirmed pneumonia and known pneumococcal serotype, urine samples of 391 CAPNETZ patients with documented pneumococcal pneumonia (i.e. positive BinaxNOW(®) Streptococcus pneumoniae urine antigen test) but unknown serotype were tested for the 13 vaccine-serotypes using SSUA. The proportion of PCV7-serotypes significantly decreased in adult patients with pneumonia from 30.6% (2002-6) to 13.3% (2007-11, ppneumococcal serotypes included by PCV13 remained stable during study period with a coverage of 61.5% (2002-06) and 59.7% (2007-11) in non-bacteremic pneumonia and 79% (for both periods) in bacteremic pneumonia, mainly due to an increase in pneumococcal serotypes 1, 3 and 7F during the second period. Thus, implementation of PCV7 in children in Germany in 2007 was associated with a significant decrease in vaccine-serotypes covered by PCV7 in adult patients with non-bacteremic pneumococcal pneumonia and with an elimination of PCV7 vaccine-serotypes in bacteremic pneumococcal pneumonia. PCV13 coverage remained high up to 2011, mainly due to an increase in serotypes 1, 3 and 7F. German Clinical Trials Register: DRKS00005274. PMID:27016653

  13. Toll like receptor-3 ligand poly-ICLC promotes the efficacy of peripheral vaccinations with tumor antigen-derived peptide epitopes in murine CNS tumor models

    Directory of Open Access Journals (Sweden)

    Eguchi Junichi

    2007-02-01

    Full Text Available Abstract Background Toll-like receptor (TLR3 ligands serve as natural inducers of pro-inflammatory cytokines capable of promoting Type-1 adaptive immunity, and TLR3 is abundantly expressed by cells within the central nervous system (CNS. To improve the efficacy of vaccine strategies directed against CNS tumors, we evaluated whether administration of a TLR3 ligand, polyinosinic-polycytidylic (poly-IC stabilized with poly-lysine and carboxymethylcellulose (poly-ICLC would enhance the anti-CNS tumor effectiveness of tumor peptide-based vaccinations. Methods C57BL/6 mice bearing syngeneic CNS GL261 glioma or M05 melanoma received subcutaneous (s.c. vaccinations with synthetic peptides encoding CTL epitopes- mEphA2 (671–679, hgp100 (25–33 and mTRP-2 (180–188 for GL261, or ovalbumin (OVA: 257–264 for M05. The mice also received intramuscular (i.m. injections with poly-ICLC. Results The combination of subcutaneous (s.c. peptide-based vaccination and i.m. poly-ICLC administration promoted systemic induction of antigen (Ag-specific Type-1 CTLs expressing very late activation antigen (VLA-4, which confers efficient CNS-tumor homing of vaccine-induced CTLs based on experiments with monoclonal antibody (mAb-mediated blockade of VLA-4. In addition, the combination treatment allowed expression of IFN-γ by CNS tumor-infiltrating CTLs, and improved the survival of tumor bearing mice in the absence of detectable autoimmunity. Conclusion These data suggest that poly-ICLC, which has been previously evaluated in clinical trials, can be effectively combined with tumor Ag-specific vaccine strategies, thereby providing a greater index of therapeutic efficacy.

  14. A phase I trial of DNA vaccination with a plasmid expressing prostate-specific antigen in patients with hormone-refractory prostate cancer.

    Science.gov (United States)

    Pavlenko, M; Roos, A-K; Lundqvist, A; Palmborg, A; Miller, A M; Ozenci, V; Bergman, B; Egevad, L; Hellström, M; Kiessling, R; Masucci, G; Wersäll, P; Nilsson, S; Pisa, P

    2004-08-16

    Prostate-specific antigen (PSA) is a serine protease secreted at low levels by normal luminal epithelial cells of the prostate and in significantly higher levels by prostate cancer cells. Therefore, PSA is a potential target for various immunotherapeutical approaches against prostate cancer. DNA vaccination has been investigated as immunotherapy for infectious diseases in patients and for specific treatment of cancer in certain animal models. In animal studies, we have demonstrated that vaccination with plasmid vector pVAX/PSA results in PSA-specific cellular response and protection against tumour challenge. The purpose of the trial was to evaluate the safety, feasibility and biological efficacy of pVAX/PSA vaccine in the clinic. A phase I trial of pVAX/PSA, together with cytokine granulocyte/macrophage-colony stimulating factor (GM-CSF) (Molgramostim) and IL-2 (Aldesleukin) as vaccine adjuvants, was carried out in patients with hormone-refractory prostate cancer. To evaluate the biologically active dose, the vaccine was administered during five cycles in doses of 100, 300 and 900 microg, with three patients in each cohort. Eight patients were evaluable. A PSA-specific cellular immune response, measured by IFN-gamma production against recombinant PSA protein, and a rise in anti-PSA IgG were detected in two of three patients after vaccination in the highest dose cohort. A decrease in the slope of PSA was observed in the two patients exhibiting IFN-gamma production to PSA. No adverse effects (WHO grade >2) were observed in any dose cohort. We demonstrate that DNA vaccination with a PSA-coding plasmid vector, given with GM-CSF and IL-2 to patients with prostate cancer, is safe and in doses of 900 microg the vaccine can induce cellular and humoral immune responses against PSA protein. PMID:15280930

  15. Characterization of sporozoite surface antigens of Plasmodium falciparum, using monoclonal antibodies. Part of a coordinated programme on the preparation of irradiated vaccines against some human diseases

    International Nuclear Information System (INIS)

    Sporozoites are considered as a source of potential vaccine. Characterization of their antigens is therefore important and can be achieved by monoclonal antibodies. The purpose of this project is to study the production of monoclonal antibodies against sporozoites of P. falciparum. Various infections of mosquitoes were carried out during the period 1981-1982 to obtain antigens for the production of hybridomas. Hybridomas were produced from mice immunized through the bites of infected mosquitoes and by intravenous inoculation. The anti-sporozoite activity of the hybridomas was tested by an immunofluorescent antibody test using P. falciparum sporozoites as antigens. Positive immunofluorescence was seen in hybridoma cell lines tested with P. falciparum, whereas negative results were obtained when the cell lines were cross-reacted with other human species (P. vivax) and with a rodent malaria parasite (P. berghei)

  16. Expression of H5 hemagglutinin vaccine antigen in common duckweed (Lemna minor) protects against H5N1 high pathogenicity avian influenza virus challenge in immunized chickens.

    Science.gov (United States)

    Bertran, Kateri; Thomas, Colleen; Guo, Xuan; Bublot, Michel; Pritchard, Nikki; Regan, Jeffrey T; Cox, Kevin M; Gasdaska, John R; Dickey, Lynn F; Kapczynski, Darrell R; Swayne, David E

    2015-07-01

    A synthetic hemagglutinin (HA) gene from the highly pathogenic avian influenza (HPAI) virus A/chicken/Indonesia/7/2003 (H5N1) (Indo/03) was expressed in aquatic plant Lemna minor (rLemna-HA). In Experiment 1, efficacy of rLemna-HA was tested on birds immunized with 0.2μg or 2.3 μg HA and challenged with 10(6) mean chicken embryo infectious doses (EID50) of homologous virus strain. Both dosages of rLemna-HA conferred clinical protection and dramatically reduced viral shedding. Almost all the birds immunized with either dosage of rLemna-HA elicited HA antibody titers against Indo/03 antigen, suggesting an association between levels of anti-Indo/03 antibodies and protection. In Experiment 2, efficacy of rLemna-HA was tested on birds immunized with 0.9 μg or 2.2 μg HA and challenged with 10(6) EID50 of heterologous H5N1 virus strains A/chicken/Vietnam/NCVD-421/2010 (VN/10) or A/chicken/West Java/PWT-WIJ/2006 (PWT/06). Birds challenged with VN/10 exhibited 100% survival regardless of immunization dosage, while birds challenged with PWT/06 had 50% and 30% mortality at 0.9 μg HA and 2.2 μg HA, respectively. For each challenge virus, viral shedding titers from 2.2 μg HA vaccinated birds were significantly lower than those from 0.9μg HA vaccinated birds, and titers from both immunized groups were in turn significantly lower than those from sham vaccinated birds. Even if immunized birds elicited HA titers against the vaccine antigen Indo/03, only the groups challenged with VN/10 developed humoral immunity against the challenge antigen. None (rLemna-HA 0.9 μg HA) and 40% (rLemna-HA 2.2 μg HA) of the immunized birds challenged with PWT/06 elicited pre-challenge antibody titers, respectively. In conclusion, Lemna-expressed HA demonstrated complete protective immunity against homologous challenge and suboptimal protection against heterologous challenge, the latter being similar to results from inactivated whole virus vaccines. Transgenic duckweed-derived HA could be a

  17. Nucleic Acid Vaccines

    Institute of Scientific and Technical Information of China (English)

    LU Shan

    2004-01-01

    @@ Anew method of immunization was discovered in the early 1990s. Several research groups independently demonstrated that direct inoculation of DNA plasmids coding for a specific protein antigen could elicit immune responses against that antigen[1-4].Since in theory the mRNA molecules also have the potential to be translated into the protein antigen, this vaccination approach was officially named by WHO as the nucleic acid vaccination even though the term DNA vaccine has been used more commonly in the literature. This novel approach is considered the fourth generation of vaccines after live attenuated vaccines, killed or inactivated vaccines and recombinant protein based subunit vaccines.

  18. Tailoring subunit vaccine immunity with adjuvant combinations and delivery routes using the Middle East respiratory coronavirus (MERS-CoV receptor-binding domain as an antigen.

    Directory of Open Access Journals (Sweden)

    Jiaming Lan

    Full Text Available The development of an effective vaccine is critical for prevention of a Middle East respiratory syndrome coronavirus (MERS-CoV pandemic. Some studies have indicated the receptor-binding domain (RBD protein of MERS-CoV spike (S is a good candidate antigen for a MERS-CoV subunit vaccine. However, highly purified proteins are typically not inherently immunogenic. We hypothesised that humoral and cell-mediated immunity would be improved with a modification of the vaccination regimen. Therefore, the immunogenicity of a novel MERS-CoV RBD-based subunit vaccine was tested in mice using different adjuvant formulations and delivery routes. Different vaccination regimens were compared in BALB/c mice immunized 3 times intramuscularly (i.m. with a vaccine containing 10 µg of recombinant MERS-CoV RBD in combination with either aluminium hydroxide (alum alone, alum and polyriboinosinic acid (poly I:C or alum and cysteine-phosphate-guanine (CpG oligodeoxynucleotides (ODN. The immune responses of mice vaccinated with RBD, incomplete Freund's adjuvant (IFA and CpG ODN by a subcutaneous (s.c. route were also investigated. We evaluated the induction of RBD-specific humoral immunity (total IgG and neutralizing antibodies and cellular immunity (ELISpot assay for IFN-γ spot-forming cells and splenocyte cytokine production. Our findings indicated that the combination of alum and CpG ODN optimized the development of RBD-specific humoral and cellular immunity following subunit vaccination. Interestingly, robust RBD-specific antibody and T-cell responses were induced in mice immunized with the rRBD protein in combination with IFA and CpG ODN, but low level of neutralizing antibodies were elicited. Our data suggest that murine immunity following subunit vaccination can be tailored using adjuvant combinations and delivery routes. The vaccination regimen used in this study is promising and could improve the protection offered by the MERS-CoV subunit vaccine by eliciting

  19. Immunization with Surface Antigen Vaccine Alone and after Treatment with 1-(2-Fluoro-5-Methyl-β-l-Arabinofuranosyl)-Uracil (l-FMAU) Breaks Humoral and Cell-Mediated Immune Tolerance in Chronic Woodchuck Hepatitis Virus Infection

    OpenAIRE

    Menne, Stephan; Roneker, Carol A.; Korba, Brent E.; Gerin, John L.; Tennant, Bud C.; Cote, Paul J

    2002-01-01

    Woodchucks chronically infected with the woodchuck hepatitis virus (WHV) were treated with the antiviral drug 1-(2-fluoro-5-methyl-β-l-arabinofuranosyl)-uracil (l-FMAU) or placebo for 32 weeks. Half the woodchucks in each group then received four injections of surface antigen vaccine during the next 16 weeks. Vaccination alone elicited a low-level antibody response to surface antigen in most carriers but did not affect serum WHV DNA and surface antigen. Carriers treated first with l-FMAU to r...

  20. The safety and reactogenicity of a reduced-antigen-content diphtheria-tetanus-acellular pertussis (dTpa) booster vaccine in healthy Vietnamese children.

    Science.gov (United States)

    Anh, Dang Duc; Jayadeva, Girish; Kuriyakose, Sherine; Han, Htay Htay

    2016-08-17

    Despite effective infant immunization against pertussis, the disease continues to circulate due to waning immunity. Booster vaccinations against pertussis beyond infancy are widely recommended. In Vietnam, however, no recommendations for pertussis boosters beyond the second year of life exist. This open-label, single-centre study was designed to assess the safety of a single booster dose of reduced-antigen-content-diphtheria-tetanus-acellular-pertussis vaccine (dTpa) in 300 healthy Vietnamese children (mean age 7.9years), who had completed primary vaccination against diphtheria, tetanus and pertussis. Solicited symptoms were recorded for 4days and unsolicited and serious adverse events (SAEs) for 31days post-vaccination. Pain and fatigue were the most common solicited local and general symptoms in 35.0% and 14.0% of children, respectively. Grade 3 swelling occurred in 3 children; no large injection site reactions or SAEs were reported. The dTpa booster vaccine was well tolerated and this study supports its administration in school age Vietnamese children. PMID:27435387

  1. Vaccination with replication-deficient recombinant adenoviruses encoding the main surface antigens of toxoplasma gondii induces immune response and protection against infection in mice.

    Science.gov (United States)

    Caetano, Bráulia C; Bruña-Romero, Oscar; Fux, Blima; Mendes, Erica A; Penido, Marcus L O; Gazzinelli, Ricardo T

    2006-04-01

    We have generated recombinant adenoviruses encoding three genetically modified surface antigens (SAGs) of the parasite Toxoplasma gondii, that is, AdSAG1, AdSAG2, and AdSAG3. Modifications included the removal of their glycosylphosphatidylinositol (GPI) anchoring motifs and, in some cases, the exchange of the native signal peptide for influenza virus hemagglutinin signal sequence. Adenovirus immunization of BALB/c mice elicited potent antibody responses against each protein, displaying a significant bias toward a helper T cell type 1 (Th1) profile in animals vaccinated with AdSAG1. Furthermore, the presence of parasite-specific IFN-gamma-producing T cells was analyzed by proliferation assays and enzyme-linked immunospot assays in the same animals. Splenocytes from immunized mice secreted IFN-gamma after in vitro stimulation with tachyzoite lysate antigen or with a fraction enriched for membrane-purified GPI-anchored proteins (F3) from the T. gondii tachyzoite surface. Epitopes recognized by CD8+ T cells were identified in SAG1 and SAG3, but not SAG2, sequences, although this protein also induced a specific response. We also tested the capacity of the immune responses detected to protect mice against a challenge with live T. gondii parasites. Although no protection was observed against tachyzoites of the highly virulent RH strain, a significant reduction in cyst loads in the brain was observed in animals challenged with the P-Br strain. Thus, up to 80% of the cysts were eliminated from animals vaccinated with a mixture of the three recombinant viruses. Because adenoviruses seemed capable of inducing Th1-biased protective immune responses against T. gondii antigens, other parasite antigens should be tested alone or in combination with those described here to further develop a protective vaccine against toxoplasmosis. PMID:16610929

  2. A combined vaccine against Brucella abortus and infectious bovine rhinotracheitis.

    Science.gov (United States)

    Kamaraj, Govindasamy; Chinchkar, Shankar R; Rajendra, Lingala; Srinivasan, Villuppanoor Alwar

    2009-06-01

    The present study was undertaken to study the immune response in calves vaccinated with Brucella abortus strain 19, infectious bovine rhinotracheitis (IBR) vaccines in monovalent form and combined vaccine containing both antigen. The seroconversion of monovalent and combined vaccines was tested in seronegative cattle calves. IBR vaccine alone and combination with live Brucella abortus S19 vaccine elicited an anamnestic response on day 60 post booster but started declining from day 90 onwards against IBR. B. abortus S19 alone and in combination with IBR vaccine gave more than 2 log protection in mice two weeks post challenge. Fluorescence polarization assay analysis with sera samples of calves vaccinated with B. abortus S19 monovalent vaccine alone and in combination with IBR vaccine revealed the presence of B. abortus antibodies. The components of the combined vaccine did not show any evidence of interference in the development of immunity. This combined vaccine may provide economical and affordable biological for the control of brucellosis and IBR. PMID:23100765

  3. Immobilization antigen vaccine adjuvanted by parasitic heat shock protein 70C confers high protection in fish against cryptocaryonosis.

    Science.gov (United States)

    Josepriya, T A; Chien, Kuo-Hsuan; Lin, Hsin-Yun; Huang, Han-Ning; Wu, Chang-Jer; Song, Yen-Ling

    2015-08-01

    The immobilization antigen (iAg) has been demonstrated as a protective immunogen against Cryptocaryon irritans infection. In this study, C-terminal domain of heat shock protein 70 cloned from C. irritans (Hsp70C) was tested for its immuno-stimulatory effects. The iAg and Hsp70C cDNAs were constructed independently in secretory forms and were encapsulated in chitosan nanoparticles. In the first immunization trial, grouper fingerlings orally intubated with iAg and iAg:Hsp70C presented 96% and 100% relative percent survival (RPS), respectively, after a lethal challenge. In the second trial, both iAg and iAg:Hsp70C groups showed 100% RPS and the skin trophont burden was significantly lowered. The iAg:Hsp70C still provides a significantly high protection of 51% RPS at 49 days post immunization, when an even more serious lethal infection occurs. RT-qPCR results showed that Hsp70C could up-regulate the expression of i) T cell markers: Cluster of Differentiation 8 alpha (CD8α) and CD4, ii) cytokine genes: Interferon gamma (IFNγ), Tumor Necrosis Factor alpha (TNFα) and Interleukin 12 p40 (IL-12/P40), iii) antibody genes: Immunoglobulin M heavy chain (IgMH) and IgTH, and iv) major histocompatibility complex (MHC-I & MHC-II), in the spleen of iAg:Hsp70C group. Furthermore, significantly high levels of iAg-specific IgM was detected in skin mucus which efficiently immobilized live theronts in iAg- and iAg:Hsp70C-immunized fish at 5 weeks post immunization. Hsp70C significantly increased the number of nonspecific CD8(+) skin leucocytes which exerted cytotoxicity against theronts, although cytotoxic activity showed no difference among the various groups. Because of this complementary cooperation of cellular and humoral immune responses, Hsp70C enhances the efficacy of iAg vaccine and constrains C. irritans infection. In view of the severe loss caused by cryptocaryonosis, application of this parasitic vaccine in farmed and ornamental fish, is worthy to be considered. PMID

  4. Development of 111In-labeled tumor-associated antigen peptides for monitoring dendritic-cell-based vaccination

    International Nuclear Information System (INIS)

    Dendritic cells (DC) are professional antigen-presenting cells capable of inducing potent immune responses. In our ongoing clinical trials, human leukocyte antigen (HLA)-A2.1+ melanoma patients are vaccinated with mature DC, presenting tumor-derived peptides in major histocompatibility complexes (MHC) to naive T cells. Previously, we have shown that both intradermally and intranodally injected 111In-labeled mature DC migrate to draining lymph nodes. However, little is known about the fate of the MHC-peptide complex after injection of these peptide-loaded DC. The aim of the present study was to develop radiolabeled, tumor-derived peptides to monitor their binding to MHC Class I. Methods: The HLA-A2.1 binding peptide gp100:154-162mod (gp100:154m) was conjugated with diethylenetriamine pentaacetic acid (DTPA) either at the N-terminus (α-DTPA-gp100:154m) or at the epsilon amino group of the Lys154 residue (ε-DTPA-gp100:154m) and labeled with 111In. Results: The maximum specific activity for both peptides was 13 GBq/μmol. The IC5 of the α-[111In]DTPA-gp100:154m peptide was >75 μM. The IC5 of the 111In-labeled ε-DTPA-gp100:154m was 3 μM, similar to the unconjugated peptide. MHC binding studies showed specific binding of the ε-[111In]DTPA-gp100:154m peptide to the JY cells at 4 deg. C. Interestingly, no specific binding was observed for the α-[111In]DTPA-gp100:154m peptide. In contrast to the α-[111In]DTPA-gp100:154m peptide, the ε-[111In]DTPA-gp100:154m peptide was recognized by cytotoxic T cells. Conclusion: When DTPA was conjugated to the epsilon NH2 group of the Lys154 residue, MHC binding of the peptide was preserved and could still be recognized by cytotoxic T cells. These studies allow the noninvasive determination of the behavior of MHC-peptide complexes on DC in vivo

  5. Viable adenovirus vaccine prototypes: High-level production of a papillomavirus capsid antigen from the major late transcriptional unit

    OpenAIRE

    Berg, Michael; DiFatta, Julie; Hoiczyk, Egbert; Schlegel, Richard; Ketner, Gary

    2005-01-01

    Safe, effective, orally delivered, live adenovirus vaccines have been in use for three decades. Recombinant derivatives of the live adenovirus vaccines may prove an economical alternative to current vaccines for a variety of diseases. To explore that possibility, we constructed a series of recombinants that express the major capsid protein (L1) of canine oral papillomavirus (COPV), a model for mucosal human papillomavirus (HPV) infection. Vaccination with virus-like particles (VLPs) composed ...

  6. Molecular characterization of HAO3, the homologue of the Bm86 tick vaccine antigen, from the Iranian isolate of Hyalomma anatolicum anatolicum.

    Science.gov (United States)

    Ebrahimi, Seyyed Mahmoud; Paykari, Habib; Memarnejadian, Arash

    2013-12-01

    Hyalomma anatolicum anatolicum tick is widely distributed in many parts of Iran and while the commercial vaccines based on the application of midgut-derived recombinant Bm86 antigen are used for its control, limited information about the efficiency of this vaccination in Iran is available. Herein, with the final aim of evaluation of Bm86-based heterologous vaccination, as the primary step the Bm86 homologue of the H. a. anatolicum (Hao3) from an Iranian isolate was characterized and compared with the commercialized Bm86 and other Bm86 homologoue sequences available in GenBank. Our in silico predictions resulted in the identification of seven epidermal growth factor (EGF)-like domains, one hydrophobic transmembrane region, one leader sequence and several glycosylation sites within the structure of both Hao3 and Bm86 proteins, which suggested the pattern of extracellular membrane-bound glycoproteins with the role of regulation in cell growth for both proteins. Moreover, while the nucleotide and amino acid sequences corresponding to Bm86 homologue showed a high level of conservation among the Iranian isolates (Hao3, Hao3-1 and Hao3-2, more than 99%), the Hao3 amino acid sequence had a homology of around 89%, 64% and 65% with that of Indian, Australian and Argentinean isolates, respectively. This indicated a considerable variation between commercial Bm86 antigen and H. a. anatolicum Bm86-like protein of Iranian and Indian isolates. Taking together, these results imply that the efficiency of commercial Bm86-based vaccine against the Iranian H. a. anatolicum may be under the question and indicates the value of the development of Hao3-based recombinant vaccines and further planning for their in vivo evaluation. PMID:20599993

  7. Rabies virus vaccines: is there a need for a pan-lyssavirus vaccine?

    Science.gov (United States)

    Evans, Jennifer S; Horton, Daniel L; Easton, Andrew J; Fooks, Anthony R; Banyard, Ashley C

    2012-12-14

    All members of the lyssavirus genus are capable of causing disease that invariably results in death following the development of clinical symptoms. The recent detection of several novel lyssavirus species across the globe, in different animal species, has demonstrated that the lyssavirus genus contains a greater degree of genetic and antigenic variation than previously suspected. The divergence of species within the genus has led to a differentiation of lyssavirus isolates based on both antigenic and genetic data into two, and potentially a third phylogroup. Critically, from both a human and animal health perspective, current rabies vaccines appear able to protect against lyssaviruses classified within phylogroup I. However no protection is afforded against phylogroup II viruses or other more divergent viruses. Here we review current knowledge regarding the diversity and antigenicity of the lyssavirus glycoprotein. We review the degree of cross protection afforded by rabies vaccines, the genetic and antigenic divergence of the lyssaviruses and potential mechanisms for the development of novel lyssavirus vaccines for use in areas where divergent lyssaviruses are known to circulate, as well as for use by those at occupational risk from these pathogens. PMID:23084854

  8. Transplacentally acquired maternal antibody against hepatitis B surface antigen in infants and its influence on the response to hepatitis B vaccine.

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    Zhiqun Wang

    Full Text Available BACKGROUND: Passively acquired maternal antibodies in infants may inhibit active immune responses to vaccines. Whether maternal antibody against hepatitis B surface antigen (anti-HBs in infants may influence the long-term immunogenicity of hepatitis B vaccine remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: Totally 338 pairs of mothers and children were enrolled. All infants were routinely vaccinated against hepatitis B based on 0-, 1- and 6-month schedule. We characterized the transplacental transfer of maternal anti-HBs, and compared anti-HBs response in children of mothers with or without anti-HBs. In a prospective observation, all 63 anti-HBs positive mothers transferred anti-HBs to their infants; 84.1% of the infants had higher anti-HBs concentrations than their mothers. One and half years after vaccination with three doses of hepatitis B vaccine, the positive rate and geometric mean concentration (GMC of anti-HBs in 32 infants with maternal anti-HBs were comparable with those in 32 infants without maternal antibody (90.6% vs 87.5%, P = 0.688, and 74.5 vs 73.5 mIU/ml, P = 0.742, respectively. In a retrospective analysis, five and half years after vaccination with three doses vaccine, the positive rates of anti-HBs in 88 children of mothers with anti-HBs ≥1000 mIU/ml, 94 children of mothers with anti-HBs 10-999 mIU/ml, and 61 children of mothers with anti-HBs <10 mIU/ml were 72.7%, 69.2%, and 63.9% (P = 0.521, respectively; anti-HBs GMC in these three groups were 38.9, 43.9, and 31.7 mIU/ml (P = 0.726, respectively. CONCLUSIONS/SIGNIFICANCE: The data demonstrate that maternal anti-HBs in infants, even at high concentrations, does not inhibit the long-term immunogenicity of hepatitis B vaccine. Thus, current hepatitis B vaccination schedule for infants will be still effective in the future when most infants are positive for maternal anti-HBs due to the massive vaccination against hepatitis B.

  9. Novel 6xHis tagged foot-and-mouth disease virus vaccine bound to nanolipoprotein adjuvant via metal ions provides antigenic distinction and effective protective immunity.

    Science.gov (United States)

    Rai, Devendra K; Segundo, Fayna Diaz-San; Schafer, Elizabeth; Burrage, Thomas G; Rodriguez, Luis L; de Los Santos, Teresa; Hoeprich, Paul D; Rieder, Elizabeth

    2016-08-01

    Here, we engineered two FMD viruses with histidine residues inserted into or fused to the FMDV capsid. Both 6xHis viruses exhibited growth kinetics, plaque morphologies and antigenic characteristics similar to wild-type virus. The 6xHis tag allowed one-step purification of the mutant virions by Co(2+) affinity columns. Electron microscopy and biochemical assays showed that the 6xHis FMDVs readily assembled into antigen: adjuvant complexes in solution, by conjugating with Ni(2+)-chelated nanolipoprotein and monophosphoryl lipid A adjuvant (MPLA:NiNLP). Animals Immunized with the inactivated 6xHis-FMDV:MPLA:NiNLP vaccine acquired enhanced protective immunity against FMDV challenge compared to virions alone. Induction of anti-6xHis and anti-FMDV neutralizing antibodies in the immunized animals could be exploited in the differentiation of vaccinated from infected animals needed for the improvement of FMD control measures. The novel marker vaccine/nanolipid technology described here has broad applications for the development of distinctive and effective immune responses to other pathogens of importance. PMID:27209448

  10. PreS1 epitope recognition in newborns after vaccination with the third-generation Sci-B-Vac™ vaccine and their relation to the antibody response to hepatitis B surface antigen

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    Madalinski Kazimierz

    2009-01-01

    Full Text Available Abstract Background Sci-B-Vac™ is a recombinant, hepatitis B vaccine derived from a mammalian cell line and containing hepatitis B surface antigen (HBsAg as well as preS1 and preS2 antigens. Few studies have been performed on the antibody responses to preS1 in relation to the antibody to hepatitis B surface antigen (anti-HBs response during immunisation of healthy children with preS-containing vaccines. Results In this study 28 healthy newborns were randomly selected to receive either 2.5 ug or 5.0 ug of the Sci-B-Vac vaccine. Children received three doses of vaccine according to a 0-, 1-, 6-month scheme. Antibodies against the S-protein and three synthetic peptides mimicking three B-cell preS1 epitopes, (21–32 amino acid epitope, (32–47 amino acid epitope and the C-terminal (amino acid epitope 94–117 were determined at 6 and 9 months. Fourteen (50% of the 28 newborns had detectable levels of anti-preS1 (21–32 antibodies; 15 (54% were anti-preS1 (32–47 reactive and 12 (43% were anti-preS1 (94–117 reactive at 6 or 9 months after initiation of the vaccination. Significantly higher levels of anti-HBs were observed in the sera of patients with detectable anti-preS1 (32–47 reactivity (24 550 ± 7375 IU/L, mean ± SEM as compared with the non-reactive sera (5991 ± 1530 IU/L, p Conclusion Recognition of several preS1 epitopes, and in particular, the epitope contained within the second half of the hepatocyte binding site localised in the hepatitis B surface protein of the third-generation hepatitis B vaccine is accompanied by a more pronounced antibody response to the S-gene-derived protein in healthy newborns.

  11. Transient Loss of Protection Afforded by a Live Attenuated Non-typhoidal Salmonella Vaccine in Mice Co-infected with Malaria

    OpenAIRE

    Mooney, Jason P.; Lee, Seung-Joo; Lokken, Kristen L.; Nanton, Minelva R.; Nuccio, Sean-Paul; Stephen J McSorley; Tsolis, Renée M.

    2015-01-01

    In immunocompetent individuals, non-typhoidal Salmonella serovars (NTS) are associated with gastroenteritis, however, there is currently an epidemic of NTS bloodstream infections in sub-Saharan Africa. Plasmodium falciparum malaria is an important risk factor for invasive NTS bloodstream in African children. Here we investigated whether a live, attenuated Salmonella vaccine could be protective in mice, in the setting of concurrent malaria. Surprisingly, mice acutely infected with the nonletha...

  12. Prime-boost vaccination with Bacillus Calmette Guerin and a recombinant adenovirus co-expressing CFP10, ESAT6, Ag85A and Ag85B of Mycobacterium tuberculosis induces robust antigen-specific immune responses in mice.

    Science.gov (United States)

    Li, Wu; Li, Min; Deng, Guangcun; Zhao, Liping; Liu, Xiaoming; Wang, Yujiong

    2015-08-01

    Tuberculosis (TB) remains to be a prevalent health issue worldwide. At present, Mycobacterium bovis Bacillus Calmette Guerin (BCG) is the singular anti-TB vaccine available for the prevention of disease in humans; however, this vaccine only provides limited protection against Mycobacterium tuberculosis (Mtb) infection. Therefore, the development of alternative vaccines and strategies for increasing the efficacy of vaccination against TB are urgently required. The present study aimed to evaluate the ability of a recombinant adenoviral vector (Ad5-CEAB) co-expressing 10-kDa culture filtrate protein, 6-kDa early-secreted antigenic target, antigen 85 (Ag85)A and Ag85B of Mtb to boost immune responses following primary vaccination with BCG in mice. The mice were first subcutaneously primed with BCG and boosted with two doses of Ad5-CEAB via an intranasal route. The immunological effects of Ad5-CEAB boosted mice primed with BCG were then evaluated using a series of immunological indexes. The results demonstrated that the prime-boost strategy induced a potent antigen-specific immune response, which was primarily characterized by an enhanced T cell response and increased production of cytokines, including interferon-γ, tumor necrosis factor-α and interleukin-2, in mice. In addition, this vaccination strategy was demonstrated to have an elevated humoral response with increased concentrations of antigen-specific bronchoalveolar lavage secretory immunoglobulin (Ig)A and serum IgG in mice compared with those primed with BCG alone. These data suggested that the regimen of subcutaneous BCG prime and mucosal Ad5-CEAB boost was a novel strategy for inducing a broad range of antigen-specific immune responses to Mtb antigens in vivo, which may provide a promising strategy for further development of adenoviral-based vaccine against Mtb infection. PMID:25962477

  13. Immunological investigations of antigens released by normal and irradiated schistosomasa mansoni cercariae in vitro. Part of a coordinated programme on preparation of irradiated vaccines against some human diseases

    International Nuclear Information System (INIS)

    S.mansoni cercariae were γ-irradiated at 1-15 K rads, syringe transformed, and injected into groups of 20 mice (200 dose), with unirradiated controls. Aliquots of 1,500 cercariae irradiated at 1-40 K rads (plus unirradiated controls) were cultured in serum-free medium. It was found that irradiation does not inhibit release of a broad spectrum of antigens in culture over 6 hours until 20 K rads is delivered. Mice used as hosts for the graded cercarial irradiation vaccine were subdivided into groups of 10 and either left unchallenged or challenged at 6 weeks with a normal infection of 200 cercariae. Serum samples were taken from every mouse at regular intervals and antibodies titrated by solid phase radioimmunoassay. Injected parasites, whether irradiated or normal, always gave higher antibody titres to cercarial and egg antigens than the equivalent dose of normal (challenge) parasites infecting by the natural route. Challenge infection depressed anti-cercarial responses in mice exposed to irradiated larvae but boosted the response to normal injected parasites. Antibodies to SEA were in lower titre in all groups but rose from week 7 (1 week post-challenge) in the groups injected with normal and 1 K rad-treated parasites, where adults were previously established in the hosts. At 12 weeks all mice were sacrificed and perfused for adults. Egg yields in liver and intestine were determined. There was no evidence of protective immunity to challenge infection induced by injected unirradiated or 1 K rad-irradiated, transformed, cercariae, even though both sources of parasite gave rise to egg-laying adults. By contrast, the 5, 10 and 15 K rad vaccines gave protection of 36-49%, even though they gave rise to no persistent adults or any deposited eggs. The protective (immunising) properties of irradiation-attenuated vaccines of S.mansoni cercariae can thus be clearly correlated with their capacity to release antigens in the immediate post irradiation period

  14. Arthropod vaccines.

    Science.gov (United States)

    Lee, R; Opdebeeck, J P

    1999-03-01

    Antigens located in the midgut of the tick are hidden from the host's immune system. Egg production of ticks can be reduced when ticks are fed on animals vaccinated with midgut antigens of the tick, and a subunit vaccine formulated with the recombinant antigen Bm86 is now available that can reduce the number of ticks infesting cattle grazing on pasture. Midgut antigens used in vaccines against insects that transmit pathogenic organisms to humans have not been as effective in reducing insect fecundity and an alternative approach may be necessary. Transmission-blocking vaccines directed at interfering with the vector-pathogen interaction could result in loss of vector competence and block the spread of disease-causing organisms. PMID:10198800

  15. Synthetic TLR4 agonists enhance functional antibodies and CD4+ T-cell responses against the Plasmodium falciparum GMZ2.6C multi-stage vaccine antigen.

    Science.gov (United States)

    Baldwin, Susan L; Roeffen, Will; Singh, Susheel K; Tiendrebeogo, Regis W; Christiansen, Michael; Beebe, Elyse; Carter, Darrick; Fox, Christopher B; Howard, Randall F; Reed, Steven G; Sauerwein, Robert; Theisen, Michael

    2016-04-27

    A subunit vaccine targeting both transmission and pathogenic asexual blood stages of Plasmodium falciparum, i.e., a multi-stage vaccine, could be a powerful tool to combat malaria. Here, we report production and characterization of the recombinant protein GMZ2.6C, which contains a fragment of the sexual-stage protein Pfs48/45-6C genetically fused to GMZ2, an asexual vaccine antigen in advanced clinical development. To select the most suitable vaccine formulation for downstream clinical studies, GMZ2.6C was tested with various immune modulators in different adjuvant formulations (stable emulsions, liposomes, and alum) in C57BL/6 mice. Some, but not all, formulations containing either the synthetic TLR4 agonist GLA or SLA elicited the highest parasite-specific antibody titers, the greatest IFN-γ responses in CD4+ TH1 cells, and the highest percentage of multifunctional CD4+ T cells expressing IFN-γ and TNF in response to GMZ2.6C. Both of these agonists have good safety records in humans. PMID:26994314

  16. Oral Delivery of a Novel Recombinant Streptococcus mitis Vector Elicits Robust Vaccine Antigen-Specific Oral Mucosal and Systemic Antibody Responses and T Cell Tolerance.

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    Emily Xie

    Full Text Available The pioneer human oral commensal bacterium Streptococcus mitis has unique biologic features that make it an attractive mucosal vaccine or therapeutic delivery vector. S. mitis is safe as a natural persistent colonizer of the mouth, throat and nasopharynx and the oral commensal bacterium is capable of inducing mucosal antibody responses. A recombinant S. mitis (rS. mitis that stably expresses HIV envelope protein was generated and tested in the germ-free mouse model to evaluate the potential usefulness of this vector as a mucosal vaccine against HIV. Oral vaccination led to the efficient and persistent bacterial colonization of the mouth and the induction of both salivary and systemic antibody responses. Interestingly, persistently colonized animals developed antigen-specific systemic T cell tolerance. Based on these findings we propose the use of rS. mitis vaccine vector for the induction of mucosal antibodies that will prevent the penetration of the mucosa by pathogens such as HIV. Moreover, the first demonstration of rS. mitis having the ability to elicit T cell tolerance suggest the potential use of rS. mitis as an immunotherapeutic vector to treat inflammatory, allergic and autoimmune diseases.

  17. Recombinant Mycobacterium bovis BCG as an HIV vaccine vector.

    Science.gov (United States)

    Chapman, Rosamund; Chege, Gerald; Shephard, Enid; Stutz, Helen; Williamson, Anna-Lise

    2010-06-01

    HIV-1 has resulted in a devastating AIDS pandemic. An effective HIV/AIDS vaccine that can be used to either, prevent HIV infection, control infection or prevent progression of the disease to AIDS is needed. In this review we discuss the use of Mycobacterium bovis BCG, the tuberculosis vaccine, as a vaccine vector for an HIV vaccine. Numerous features make BCG an attractive vehicle to deliver HIV antigens. It has a good safety profile, elicits long-lasting cellular immune responses and in addition manufacturing costs are affordable, a necessary consideration for developing countries. In this review we discuss the numerous factors that influence generation of a genetically stable recombinant BCG vaccine for HIV. PMID:20353397

  18. Induction of immune tolerance in asthmatic mice by vaccination with DNA encoding an allergen-cytotoxic T lymphocyte-associated antigen 4 combination.

    Science.gov (United States)

    Zhang, Fang; Huang, Gang; Hu, Bo; Song, Yong; Shi, Yi

    2011-05-01

    Allergen-specific immunotherapy is a potential treatment for allergic diseases. We constructed an allergen-cytotoxic T lymphocyte-associated antigen 4 (CTLA-4)-encoding DNA vaccine, administered it directly to antigen-presenting cells (APCs), and investigated its ability and mechanisms to ameliorate allergic airway inflammation in an asthmatic mouse model. An allergen-CTLA-4 DNA plasmid (OVA-CTLA-4-pcDNA₃.₁) encoding an ovalbumin (OVA) and the mouse CTLA-4 extracellular domain was constructed and transfected into COS-7 cells to obtain the fusion protein OVA-CTLA-4, which was able to bind the B7 ligand on dendritic cells (DCs), and induced CD25⁺ Foxp3⁺ regulatory T (Treg) cells by the coculture of naive CD4⁺ T cells with DCs in vitro. In an animal study, BALB/c mice were sensitized and challenged with OVA to establish the asthmatic model. Vaccination with a high dose of OVA-CTLA-4-pcDNA₃.₁ significantly decreased interleukin-4 (IL-4) and IL-5 levels and eosinophil counts and prevented OVA-induced reduction of the gamma interferon level in the bronchoalveolar lavage fluid. In addition, these mice suffered less severe airway inflammation and had lower levels of OVA-specific IgE and IgG1 titers in serum. Also, high-dose OVA-CTLA-4-pcDNA₃.₁ vaccination inhibited the development of airway hyperreactivity and prevented OVA-induced reduction of the percentages of Foxp3⁺ Treg cells in the spleen. Our results indicate that a high dose of allergen-CTLA-4-encoding DNA vaccine was more effective in preventing an allergen-induced Th2-skewed immune response through the induction of Treg cells and may be a new alternative therapy for asthma. PMID:21346053

  19. Vaccination with Brucella abortus Recombinant In Vivo-Induced Antigens Reduces Bacterial Load and Promotes Clearance in a Mouse Model for Infection

    OpenAIRE

    Jake E Lowry; Isaak, Dale D.; Leonhardt, Jack A.; Giulia Vernati; Jessie C Pate; Andrews, Gerard P.

    2011-01-01

    Current vaccines used for the prevention of brucellosis are ineffective in inducing protective immunity in animals that are chronically infected with Brucella abortus, such as elk. Using a gene discovery approach, in vivo-induced antigen technology (IVIAT) on B. abortus, we previously identified ten loci that encode products up-regulated during infection in elk and consequently may play a role in virulence. In our present study, five of the loci (D15, 0187, VirJ, Mdh, AfuA) were selected for ...

  20. Quantitative Detection of the Foot-And-Mouth Disease Virus Serotype O 146S Antigen for Vaccine Production Using a Double-Antibody Sandwich ELISA and Nonlinear Standard Curves

    Science.gov (United States)

    Feng, Xia; Ma, Jun-Wu; Sun, Shi-Qi; Guo, Hui-Chen; Yang, Ya-Min; Jin, Ye; Zhou, Guang-Qing; He, Ji-Jun; Guo, Jian-Hong; Qi, Shu-yun; Lin, Mi; Cai, Hu; Liu, Xiang-Tao

    2016-01-01

    The efficacy of an inactivated foot-and-mouth disease (FMD) vaccine is mainly dependent on the integrity of the foot-and-mouth disease virus (FMDV) particles. At present, the standard method to quantify the active component, the 146S antigen, of FMD vaccines is sucrose density gradient (SDG) analysis. However, this method is highly operator dependent and difficult to automate. In contrast, the enzyme-linked immunosorbent assay (ELISA) is a time-saving technique that provides greater simplicity and sensitivity. To establish a valid method to detect and quantify the 146S antigen of a serotype O FMD vaccine, a double-antibody sandwich (DAS) ELISA was compared with an SDG analysis. The DAS ELISA was highly correlated with the SDG method (R2 = 0.9215, P<0.01). In contrast to the SDG method, the DAS ELISA was rapid, robust, repeatable and highly sensitive, with a minimum quantification limit of 0.06 μg/mL. This method can be used to determine the effective antigen yields in inactivated vaccines and thus represents an alternative for assessing the potency of FMD vaccines in vitro. But it still needs to be prospectively validated by analyzing a new vaccine preparation and determining the proper protective dose followed by an in vivo vaccination-challenge study to confirm the ELISA findings. PMID:26930597

  1. Quantitative Detection of the Foot-And-Mouth Disease Virus Serotype O 146S Antigen for Vaccine Production Using a Double-Antibody Sandwich ELISA and Nonlinear Standard Curves.

    Science.gov (United States)

    Feng, Xia; Ma, Jun-Wu; Sun, Shi-Qi; Guo, Hui-Chen; Yang, Ya-Min; Jin, Ye; Zhou, Guang-Qing; He, Ji-Jun; Guo, Jian-Hong; Qi, Shu-yun; Lin, Mi; Cai, Hu; Liu, Xiang-Tao

    2016-01-01

    The efficacy of an inactivated foot-and-mouth disease (FMD) vaccine is mainly dependent on the integrity of the foot-and-mouth disease virus (FMDV) particles. At present, the standard method to quantify the active component, the 146S antigen, of FMD vaccines is sucrose density gradient (SDG) analysis. However, this method is highly operator dependent and difficult to automate. In contrast, the enzyme-linked immunosorbent assay (ELISA) is a time-saving technique that provides greater simplicity and sensitivity. To establish a valid method to detect and quantify the 146S antigen of a serotype O FMD vaccine, a double-antibody sandwich (DAS) ELISA was compared with an SDG analysis. The DAS ELISA was highly correlated with the SDG method (R2 = 0.9215, P<0.01). In contrast to the SDG method, the DAS ELISA was rapid, robust, repeatable and highly sensitive, with a minimum quantification limit of 0.06 μg/mL. This method can be used to determine the effective antigen yields in inactivated vaccines and thus represents an alternative for assessing the potency of FMD vaccines in vitro. But it still needs to be prospectively validated by analyzing a new vaccine preparation and determining the proper protective dose followed by an in vivo vaccination-challenge study to confirm the ELISA findings. PMID:26930597

  2. Quantitative Detection of the Foot-And-Mouth Disease Virus Serotype O 146S Antigen for Vaccine Production Using a Double-Antibody Sandwich ELISA and Nonlinear Standard Curves.

    Directory of Open Access Journals (Sweden)

    Xia Feng

    Full Text Available The efficacy of an inactivated foot-and-mouth disease (FMD vaccine is mainly dependent on the integrity of the foot-and-mouth disease virus (FMDV particles. At present, the standard method to quantify the active component, the 146S antigen, of FMD vaccines is sucrose density gradient (SDG analysis. However, this method is highly operator dependent and difficult to automate. In contrast, the enzyme-linked immunosorbent assay (ELISA is a time-saving technique that provides greater simplicity and sensitivity. To establish a valid method to detect and quantify the 146S antigen of a serotype O FMD vaccine, a double-antibody sandwich (DAS ELISA was compared with an SDG analysis. The DAS ELISA was highly correlated with the SDG method (R2 = 0.9215, P<0.01. In contrast to the SDG method, the DAS ELISA was rapid, robust, repeatable and highly sensitive, with a minimum quantification limit of 0.06 μg/mL. This method can be used to determine the effective antigen yields in inactivated vaccines and thus represents an alternative for assessing the potency of FMD vaccines in vitro. But it still needs to be prospectively validated by analyzing a new vaccine preparation and determining the proper protective dose followed by an in vivo vaccination-challenge study to confirm the ELISA findings.

  3. A DNA vaccine encoding mutated HPV58 mE6E7-Fc-GPI fusion antigen and GM-CSF and B7.1

    Directory of Open Access Journals (Sweden)

    Wang H

    2015-10-01

    Full Text Available He Wang,1 Jiyun Yu,2 Li Li1 1Department of Gynecologic Oncology, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, 2Institute of Basic Medical Sciences, Academy of Military Medical Sciences, Beijing, People’s Republic of China Background: Persistent infection with high-risk human papillomavirus (HPV is a predominant cause of cervical cancer, and HPV58 is the third most common virus detected in the patients with cervical cancer in Asia. E6 and E7 are the viral oncogenes which are constitutively expressed in HPV-associated tumor cells and can be used as target antigens for related immunotherapy. In this study, we modified the HPV58 E6 and E7 oncogenes to eliminate their oncogenic potential and constructed a recombinant DNA vaccine that coexpresses the sig-HPV58 mE6E7-Fc-GPI fusion antigen in addition to granulocyte-macrophage colony-stimulating factor (GM-CSF and B7.1 as molecular adjuvants (PVAX1-HPV58 mE6E7FcGB for the treatment of HPV58 (+ cancer. Methods: PVAX1-HPV58 mE6E7FcGB recombinant DNA vaccine was constructed to express a fusion protein containing a signal peptide, a modified HPV58 mE6E7 gene, and human IgG Fc and glycosylphosphatidylinositol (GPI-anchoring sequences using the modified DNA vaccine vector PVAX1-IRES-GM/B7.1 that coexpresses GM-CSF, and B7.1. C57BL/6 mice were challenged by HPV58 E6E7-expressing B16-HPV58 E6E7 cells, followed by immunization by PVAX1-HPV58 mE6E7FcGB vaccine on days 7, 14, 21 after tumor challenge. The cellular immune responses in immunized mice were assessed by measuring IFN-γ production in splenocytes upon stimulation by HPV58 E6E7-GST protein and the lysis of B16-HPV58 E6E7 target cells by splenocytes after restimulation with HPV58 E6E7-GST protein. The antitumor efficacy was evaluated by monitoring the growth of the tumor. Results: PVAX1-HPV58 mE6E7FcGB elicited varying levels of IFN-lsgdB58onn T-cell immune responses and lysis of target cell in mice in response to the

  4. The Immunomodulatory Role of Adjuvants in Vaccines Formulated with the Recombinant Antigens Ov-103 and Ov-RAL-2 against Onchocerca volvulus in Mice.

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    Jessica A Hess

    2016-07-01

    Full Text Available In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administration, although there is concern based on several factors that onchocerciasis cannot be eliminated solely through this approach. A vaccine against Onchocerca volvulus would provide a critical tool for the ultimate elimination of this infection. Previous studies have demonstrated that immunization of mice with Ov-103 and Ov-RAL-2, when formulated with alum, induced protective immunity. It was hypothesized that the levels of protective immunity induced with the two recombinant antigens formulated with alum would be improved by formulation with other adjuvants known to enhance different types of antigen-specific immune responses.Immunizing mice with Ov-103 and Ov-RAL-2 in conjunction with alum, Advax 2 and MF59 induced significant levels of larval killing and host protection. The immune response was biased towards Th2 with all three of the adjuvants, with IgG1 the dominant antibody. Improved larval killing and host protection was observed in mice immunized with co-administered Ov-103 and Ov-RAL-2 in conjunction with each of the three adjuvants as compared to single immunizations. Antigen-specific antibody titers were significantly increased in mice immunized concurrently with the two antigens. Based on chemokine levels, it appears that neutrophils and eosinophils participate in the protective immune response induced by Ov-103, and macrophages and neutrophils participate in immunity induced by Ov-RAL-2.The mechanism of protective immunity induced by Ov-103 and Ov-RAL-2, with the adjuvants alum, Advax 2 and MF59, appears to be multifactorial with roles for cytokines, chemokines, antibody and specific effector cells. The vaccines developed in this study have the potential of reducing the morbidity associated with onchocerciasis in humans.

  5. Conserved regions ofPlasmodium vivax potential vaccine candidate antigens in Sri Lanka:Consciousin silico analysis of prospective conformational epitope regions

    Institute of Scientific and Technical Information of China (English)

    Shanika Amarasinghe; Hashendra Kathriarachchi; Preethi Udagama

    2014-01-01

    Objective:To do mapping and modeling of conformationalB cell epitope regions of highly conserved and protective regions of three merozoitecandidate vaccine proteins ofPlasmodium vivax(P. vivax) ,ie. merozoite purface protein-1(PvMSP-1), apical membrane antigen -1 domainⅡ(PvAMA1-DⅡ) and regionⅡ of theDuffy binding protein(PvDBPⅡ), and to analyze the immunogenic properties of these predicted epitopes.Methods:3-D structures of amino acid haplotypes fromSriLanka(available inGeneBank) ofPvMSP-119(n=27),PvAMA1-DⅡ(n=21) andPvDBPⅡ(n=33) were modeled.SEPPA, selected as the best online server was used for conformational epitope predictions, while prediction and modeling of protein structure and properties related to immunogenicity was carried out withGeno3D server,SCRATCHProtein Server,NetSurfPServer and standalonesoftware,Genious5.4.4.Results:SEPPA revealed that regions of predicted conformational epitopes formed4 clusters inPvMSP-I19, and3 clusters each inPvAMA1-DⅡ andPvDBPⅡ, all of which displayed a high degree of hydrophilicity, contained solvent exposed residues, displayed high probability of antigenicity and showed positive antigenic propensity values, that indicated high degree of immunogenicity.Conclusions:Findings of this study revealed and confirmed that different parts of the sequences of each of the conserved regions of the three selected potential vaccine candidate antigens ofP. vivax are important with regard to conformational epitope prediction that warrants further laboratory experimental investigations in in vivo animal models.

  6. Assessing the relationship between antigenicity and immunogenicity of human rabies vaccines. Results of a meta-analysis.

    Science.gov (United States)

    Sudarshan, M K; Mahendra, B J; Madhusudana, S N; Narayana, D H Ashwath; Sanjay, T V; Gangaboraiah; Anandagiri, M S

    2005-01-01

    A meta-analysis was done to study the relationship between antigenecity and immunogenecity of human rabies vaccines. The data of ten cell culture human rabies vaccine studies conducted at a single centre during 1993-2004 were used in the study. The vaccines studied included Purified Chick Embryo Cell Vaccine (Kaketsuken, Japan and Rabipur, India), Purified Vero cell Rabies Vaccine (Verorab, France), Human Diploid Cell Vaccine (MIRV, France and Rabivax, Adsorbed and Lyophilized, India) and Rhesus Diploid Rabies Vaccine (adsorbed, USA). Interestingly, it was revealed that an higher antigenecity of rabies vaccines viz. potency of > or = 5 IU per single intramuscular dose did not result in significantly higher immunogenecity, as measured by rabies virus neutralizing antibody (RVNA) titers in the vaccinees, both on day 14 (t = 0.42, p > 0.66, GMR = 1.06, 95% CI of GMR = 0.82, 1.37) and day 90 (t = 0.80, p > 0.43, GMR = 1.15, 95% CI of GMR = 0.74, 1.14). However, as there are no reports of meta-analysis of cell culture human rabies vaccine trials, to confirm this observation the authors recommend further studies in this regard. PMID:17033270

  7. Significance of Response to Hepatitis B Recombinant Vaccine in Subjects with Isolated Antibody to Hepatitis B Core Antigen.

    Science.gov (United States)

    Bahari, Ali; Izadi, Shahrokh; Bari, Zohreh; Khosravi, Soheyla; Baghaei, Bita; Saneimoghadam, Esmaeil; Firouzi, Farzad; Espiari, Ali; Esmaeilzadeh, Abbas; Mokhtarifar, Ali; Bakhshipour, Alireza; Ganji, Azita

    2015-10-01

    BACKGROUND It is important to differentiate whether isolated anti-HBc is due to false positive results or the prior exposure to hepatitis B virus, because individuals with false-positive anti-HBc can benefit from vaccination and their blood can be safely transfused. To distinguish between these two conditions, we evaluated the serologic response to hepatitis B vaccine. METHODS Ninety subjects with isolated anti-HBc (cases) and 100 subjects with totally negative hepatitis B serologic markers (controls) were recruited to receive three doses of hepatitis-B (HB) vaccine. Thirty days after the first dose of the vaccine, anti-HBs titers were checked and individuals with anti-HBs titer >50 mIU/mL did not receive additional doses of the vaccine. However, others completed the vaccination course, and another blood sample was collected 30 days after the third dose to measure anti-HBs level. RESULTS Nineteen (21.1%) cases and three (3%) controls had no sero-conversion (anti-HBs titers vaccine, but the rate was significantly lower (5%) in the control group (pvaccination. CONCLUSION More than 75% of individuals with positive isolated anti-HBc can benefit from vaccination and can be included in donor pool. Also, one fifth seemed to have occult HBV infection. So HB vaccination may be used as a diagnostic tool for clarifying the situation of the subjects with isolated anti-HBc. PMID:26609352

  8. Tissue reduction of map numbers after post-exposure vaccination with single latency antigen is improved by combination with acute-stage antigens in goats

    DEFF Research Database (Denmark)

    Thakur, Aneesh; Aagaard, C.; Melvang, Heidi Mikkelsen;

    compared to unvaccinated control goats. FET11 and FET13 vaccination, however, provided significantly protection with absent or very low Map numbers in tissues. No goats seroconverted in ID Screen® ELISA, except for a single goat in the unvaccinated control group at last sampling prior to euthanasia. PPDj...

  9. Cross-stage immunity for malaria vaccine development.

    Science.gov (United States)

    Nahrendorf, Wiebke; Scholzen, Anja; Sauerwein, Robert W; Langhorne, Jean

    2015-12-22

    A vaccine against malaria is urgently needed for control and eventual eradication. Different approaches are pursued to induce either sterile immunity directed against pre-erythrocytic parasites or to mimic naturally acquired immunity by controlling blood-stage parasite densities and disease severity. Pre-erythrocytic and blood-stage malaria vaccines are often seen as opposing tactics, but it is likely that they have to be combined into a multi-stage malaria vaccine to be optimally safe and effective. Since many antigenic targets are shared between liver- and blood-stage parasites, malaria vaccines have the potential to elicit cross-stage protection with immune mechanisms against both stages complementing and enhancing each other. Here we discuss evidence from pre-erythrocytic and blood-stage subunit and whole parasite vaccination approaches that show that protection against malaria is not necessarily stage-specific. Parasites arresting at late liver-stages especially, can induce powerful blood-stage immunity, and similarly exposure to blood-stage parasites can afford pre-erythrocytic immunity. The incorporation of a blood-stage component into a multi-stage malaria vaccine would hence not only combat breakthrough infections in the blood should the pre-erythrocytic component fail to induce sterile protection, but would also actively enhance the pre-erythrocytic potency of this vaccine. We therefore advocate that future studies should concentrate on the identification of cross-stage protective malaria antigens, which can empower multi-stage malaria vaccine development. PMID:26469724

  10. Vaccination with an adenoviral vector encoding the tumor antigen directly linked to invariant chain induces potent CD4(+) T-cell-independent CD8(+) T-cell-mediated tumor control

    DEFF Research Database (Denmark)

    Sorensen, Maria R; Holst, Peter J; Pircher, Hanspeter;

    2009-01-01

    Antigen-specific immunotherapy is an attractive strategy for cancer control. In the context of antiviral vaccines, adenoviral vectors have emerged as a favorable means for immunization. Therefore, we chose a strategy combining use of these vectors with another successful approach, namely linkage of...... the vaccine antigen to invariant chain (Ii). To evaluate this strategy we used a mouse model, in which an immunodominant epitope (GP33) of the LCMV glycoprotein (GP) represents the tumor-associated neoantigen. Prophylactic vaccination of C57BL/6 mice with a replication-deficient human adenovirus 5...... than vaccination with adenovirus expressing GP alone (Ad-GP), or GP and Ii unlinked (Ad-GP+Ii). Ad-Ii-GP- induced tumor control depended on an improved generation of the tumor-associated neoantigen-specific CD8(+) T-cell response and was independent of CD4(+) T cells. IFN-gamma was shown to be a key...

  11. Phase I study of safety and immunogenicity of an Escherichia coli-derived recombinant protective antigen (rPA vaccine to prevent anthrax in adults.

    Directory of Open Access Journals (Sweden)

    Bruce K Brown

    Full Text Available BACKGROUND: The fatal disease caused by Bacillus anthracis is preventable with a prophylactic vaccine. The currently available anthrax vaccine requires a lengthy immunization schedule, and simpler and more immunogenic options for protection against anthrax are a priority for development. In this report we describe a phase I clinical trial testing the safety and immunogenicity of an anthrax vaccine using recombinant Escherichia coli-derived, B. anthracis protective antigen (rPA. METHODOLOGY/PRINCIPAL FINDINGS: A total of 73 healthy adults ages 18-40 were enrolled and 67 received 2 injections separated by 4 weeks of either buffered saline placebo, or rPA formulated with or without 704 µg/ml Alhydrogel® adjuvant in increasing doses (5, 25, 50, 100 µg of rPA. Participants were followed for one year and safety and immunologic data were assessed. Tenderness and warmth were the most common post-injection site reactions. No serious adverse events related to the vaccine were observed. The most robust humoral immune responses were observed in subjects receiving 50 µg of rPA formulated with Alhydrogel® with a geometric mean concentration of anti-rPA IgG antibodies of 283 µg/ml and a toxin neutralizing geometric 50% reciprocal geometric mean titer of 1061. The highest lymphoproliferative peak cellular response (median Lymphocyte Stimulation Index of 29 was observed in the group receiving 25 µg Alhydrogel®-formulated rPA. CONCLUSIONS/SIGNIFICANCE: The vaccine was safe, well tolerated and stimulated a robust humoral and cellular response after two doses. TRIAL REGISTRATION: ClinicalTrials.gov NCT00057525.

  12. DNA-based vaccination induces humoral and cellular immune responses against hepatitis B virus surface antigen in mice without activation of Cmyc

    Institute of Scientific and Technical Information of China (English)

    Lian San Zhao; Shan Qin; Tao You Zhou; Hong Tang; Li Liu; Bing Jun Lei

    2000-01-01

    AIM To develop a safe and effective DNA vaccine for inducing humoral and cellular immunological responses against hepatitis B virus surface antigen (HBsAg). METHODS BALB/c mice were inoculated with NV-HB/s, a recombinant plasmid that had been inserted S gene of hepatitis B virus genome and could express HBsAg in eukaryotes. HBsAg expression was measured by ABC immunohistochemical assay, generation of anti-HBs by ELISA and cytotoxic T lymphocyte (CTL), by MTT method, existence of vaccine DNA by Southern blot hybridization and activation of oncogene C-myc by in situ hybridization.RESULTS With NV-HB/s vaccination by intramuscular injection, anti-HBs was initially positive 2 weeks after inoculation while all mice tested were HBsAg positive in the muscles. The titers and seroconversion rate of anti-HBs were steadily increasing as time went on and were dose-dependent. All the mice inoculated with 100 μg NV-HB/ s were anti-HBs positive one month after inoculation, the titer was 1:1024 or more. The humoral immune response was similar induced by either intramuscular or intradermal injection. CTL activities were much stronger (45.26%) in NV-HB/s DNA immunized mice as compared with those (only 6%) in plasmaderived HBsAg vaccine immunized mice. Two months after inoculation, all muscle samples were positive by Southern-blot hybridization for NV-HB/s DNA detection, but decreased to 25%and all were undetectable by in situ hybridization after 6 months. No oncogene Cmyc activation was found in the muscle of inoculation site. CONCLUSION NV-HB/s could generate humoral and cellular immunological responses against HBsAg that had been safely expressed in situ by NV-HB/s vaccination.

  13. cDNA library construction and isolation of genes for candidate vaccine antigens from Chrysomya bezziana (the Old World Screwworm fly

    Directory of Open Access Journals (Sweden)

    Tony Voucolo

    2000-10-01

    Full Text Available The construction and use of cDNA libraries for the isolation of genes encoding candidate antigens for use in a recombinant vaccine against Chrysomya bezziana is described. RNA was isolated and mRNA purified from first and third instar larvae of Chrysomya bezziana and used in the synthesis of two cDNA libraries in the bacteriophage vector λ ZAP express®. These libraries were screened using Digoxigenin-labeled DNA probes obtained from two independent approaches. First, a homolog approach used probes designed from previously characterized peritrophic membrane genes identified from the related myiasis fly, Lucilia cuprina. Secondly, a de novo approach used amino-terminal and internal peptide sequence information derived from purified Chrysomya bezziana peritrophic membrane proteins to generate DNA probes. Three peritrophic membrane genes were identified and characterized. Chrysomya bezziana peritrophin-48 was identified using the homolog approach and, Chrysomya bezziana peritrophin-15 and Chrysomya bezziana peritrophin-42 were identified using the de novo approach. The identification of these genes as encoding candidate antigens against Chrysomya bezziana has allowed the production of recombinant proteins for use in vaccination trials

  14. AN IMMUNOTHERAPEUTIC CONCEPT OF MICROBIAL ANTIGEN APPLICATION IN ATOPY AND DISORDERS ASSOCIATED WITH FACULTATIVE MICROFLORA, AS EXEMPLIFIED BY A POLYCOMPONENT IMMUNOVAC VP4 VACCINE

    Directory of Open Access Journals (Sweden)

    N. B. Egorova

    2008-01-01

    Full Text Available Abstract. Immunomodulating drugs play an important role in therapy and prevention of numeous diseases associated with altered immune functions. Immunomodulators of bacterial origin are the most active ones, serving as a basis for design of therapeutic vaccines that are capable of stimulating antigen-specific response, along with nonspecific actions. The Immunovac VP4 poly-component vaccine is among such preparations, being a potent activator of innate immunity and showing protective activities against a number of facultative pathogens. In present review, the data are summarized that concern therapeutic effects of Immunovac VP4 in various disorders (lung abscess, chronic bronchitis, bronchial asthma, atopic dermatitis, pyodermia, herpes, acute respiratory infections. In all cases, high clinical effect was registered, i.e., decrease in number and severity of relapses, decreased dosage/number of medical drugs applied, prolongation of remission states, and transition to less severe clinical forms. The therapeutic effect is accompanied by sufficient positive dynamics of immunological parameters, e.g., phagocytic activity of macrophages, increase in lymphocytes bearing CD4, CD8, CD16, CD72, CD21 markers, enhanced IFNγ and IFNα production, correction of Ig synthesis, increased antibody titers and affinity. Analysis of data from strictly controlled studies performed in limited clinical samples, has shown a number of general regularities for common effects of microbial antigens in various disorders including allergic diseases.

  15. A New Potent Route of DNA Vaccine Inoculation: DNA-Liposome Complexes on Bare Skin Induce Antigen-Special Antibody Responses

    Directory of Open Access Journals (Sweden)

    Mingxing Duan

    2003-01-01

    Full Text Available Transcutaneous immunization is a novel strategy for genetic vaccine immunization to induce detectable antigen-special antibody in humor and mucosal. In this study, plasmid expressing hepatitis B surface antigen (pGFP-HBsAg was encapsulated in liposome, then DNA- liposome complexes were glued on bare skin of mice ear in different dosage (50μg, 10μg and 1μg. As control, DNA- liposome complexes of pGFP-HBsAg and pGFP vector were inoculated intraperitoneally. The anti-HBsAg antibodies of serum were detected weekly by ELISA. It was found that the detectable antibodies of transcutaneous immunized mouse were elicited after four weeks, and reached a maximum at the sixth week. Even 1μg plasmid DNA in liposomes through immune skin can elicit the highest ELISA antibody titer (> 1:512 in test group, and corresponding percentage of positive response is up to 71% at sixth week, but higher amounts of plasmid DNA (50μg DNA per mice on immune skin cannot induce higher antibody levels. The result showed that DNA- liposome complexes glued on bare skin appear to be a novel method for the administration of DNA vaccines.

  16. Studies on the surface antigenicity and susceptibility to antibody-dependent killing of developing schistosomula using sera from chronically infected mice and mice vaccinated with irradiated cercariae

    International Nuclear Information System (INIS)

    Changes in the surface antigenicity and susceptibility to in vitro killing during development of schistosomula of Schistosoma mansoni were studied using serum from chronically infected mice (CIS) and from mice vaccinated with highly irradiated (20 krad) cercariae (VS). Binding of these sera was quantitated by counting the number of P388D1 cells (a transformed, macrophage-like cell of mouse origin, bearing Fc receptors for IgG) binding to the parasite surface. Compared with schistosomula derived in vitro by mechanical transformation (MS), schistosomula recovered 3 hr after skin penetration in vitro (SS) showed a significant loss in surface binding of CIS. Schistosomula recovered 3 hr after skin penetration in vivo (SRS) showed even less binding, and this trend continued such that parasites recovered from the lungs 5 days after infection (LS) showed only minimal binding, and 10-day-old worms from the portal system showed no significant binding. In contrast, VS, which bound significantly less well to MS than CIS, showed enhanced binding to SS, and in the face of their declining antigenicity with respect to CIS, 3- to 24-hr SRS maintained this raised level of antigenicity. Although there appeared to be a decline in binding of VS thereafter, LS remained antigenic, still binding as many cells as MS did despite the fact that they also expressed host antigens detected usng antisera raised against mouse RBC. In spite of this persistence of VS binding up to the lung stage, resistance to eosinophil-mediated killing in vitro had developed by 48 hr post-infection, and LS were totally resistant to both eosinophil- and C-mediated killing

  17. Studies on the surface antigenicity and susceptibility to antibody-dependent killing of developing schistosomula using sera from chronically infected mice and mice vaccinated with irradiated cercariae

    Energy Technology Data Exchange (ETDEWEB)

    Bickle, Q.D.; Ford, M.J.

    1982-05-01

    Changes in the surface antigenicity and susceptibility to in vitro killing during development of schistosomula of Schistosoma mansoni were studied using serum from chronically infected mice (CIS) and from mice vaccinated with highly irradiated (20 krad) cercariae (VS). Binding of these sera was quantitated by counting the number of P388D/sub 1/ cells (a transformed, macrophage-like cell of mouse origin, bearing Fc receptors for IgG) binding to the parasite surface. Compared with schistosomula derived in vitro by mechanical transformation (MS), schistosomula recovered 3 hr after skin penetration in vitro (SS) showed a significant loss in surface binding of CIS. Schistosomula recovered 3 hr after skin penetration in vivo (SRS) showed even less binding, and this trend continued such that parasites recovered from the lungs 5 days after infection (LS) showed only minimal binding, and 10-day-old worms from the portal system showed no significant binding. In contrast, VS, which bound significantly less well to MS than CIS, showed enhanced binding to SS, and in the face of their declining antigenicity with respect to CIS, 3- to 24-hr SRS maintained this raised level of antigenicity. Although there appeared to be a decline in binding of VS thereafter, LS remained antigenic, still binding as many cells as MS did despite the fact that they also expressed host antigens detected usng antisera raised against mouse RBC. In spite of this persistence of VS binding up to the lung stage, resistance to eosinophil-mediated killing in vitro had developed by 48 hr post-infection, and LS were totally resistant to both eosinophil- and C-mediated killing.

  18. Simulation of control strategies for the cattle tick Boophilus microplus employing vaccination with a recombinant Bm86 antigen preparation.

    Science.gov (United States)

    Labarta, V; Rodríguez, M; Penichet, M; Lleonart, R; Luaces, L L; de la Fuente, J

    1996-05-01

    Current strategies for the control of the cattle tick Boophilus microplus include the use of chemicals as the principal control method. These methods, however, have met with partially successful results. The recent development of immunological methods for the control of the cattle tick has opened new possibilities for the design of control strategies. Employing the results obtained by us in experiments testing the effect of vaccination with the recombinant vaccine, Gavac (Heber Biotec S.A.), on tick populations, we have developed a model to evaluate, through a computer program, the efficacy of the vaccine as a control method. The action of the vaccine on the control of tick populations was simulated and the specific serum antibody titers required to decrease the tick population in the field were calculated. The specific serum antibody titer required to decrease the tick population in the field after the first vaccination scheme was found to be > or = 57,200 and the antibody titer required to maintain this effect when the vaccine is already acting and after successive revaccinations was found to be > or = 27,500. Considerations about revaccination schemes and combination between vaccination and acaricide treatments as possible control strategies are discussed. PMID:8792587

  19. Nanoparticle-based targeting of vaccine compounds to skin antigen-presenting cells by hair follicles and their transport in mice.

    Science.gov (United States)

    Mahe, Brice; Vogt, Annika; Liard, Christelle; Duffy, Darragh; Abadie, Valérie; Bonduelle, Olivia; Boissonnas, Alexandre; Sterry, Wolfram; Verrier, Bernard; Blume-Peytavi, Ulrike; Combadiere, Behazine

    2009-05-01

    Particle-based drug delivery systems target active compounds to the hair follicle and may result in a better penetration and higher efficiency of compound uptake by skin resident cells. As previously proposed, such delivery systems could be important tools for vaccine delivery. In this study, we investigated the penetration of solid fluorescent 40 or 200 nm polystyrene nanoparticles (NPs) as well as virus particles in murine skin to further investigate the efficacy of transcutaneously (TC) applied particulate vaccine delivery route. We demonstrated that 40 and 200 nm NPs and modified vaccinia Ankara (MVA) expressing the green-fluorescent protein penetrated deeply into hair follicles and were internalized by perifollicular antigen-presenting cells (APCs). Fibered-based confocal microscopy analyses allowed visualizing in vivo particle penetration along the follicular duct, diffusion into the surrounding tissue, uptake by APCs and transport to the draining lymph nodes. The application of small particles, such as ovalbumin coding DNA or MVA, induced both humoral and cellular immune responses. Furthermore, TC applied MVA induced protection against vaccinia virus challenge. Our results strengthen the concept of TC targeting of cutaneous APCs by hair follicles and will contribute to the development of advanced vaccination protocols using NPs or viral vectors. PMID:19052565

  20. Use of the alpha-hemolysin secretion system of Escherichia coli for antigen delivery in the Salmonella typhi Ty21a vaccine strain.

    Science.gov (United States)

    Gentschev, Ivaylo; Dietrich, Guido; Spreng, Simone; Neuhaus, Beatrice; Maier, Elke; Benz, Roland; Goebel, Werner; Fensterle, Joachim; Rapp, Ulf R

    2004-10-01

    This study examined the suitability of the hemolysin secretion system of Escherichia coli for expression and delivery of alpha-hemolysin (HlyA) by the S. typhi Ty21a strain, the only live oral Salmonella vaccine strain licensed for human use, under in vitro and in vivo conditions. For this purpose, two plasmid vectors encoding either the whole alpha-hemolysin of E. coli (pANN202-812/pMOhly2) or the hemolysin secretion signal (pMOhly1) were transferred into S. typhi Ty21a. S. typhi Ty21a carrying pANN202-812/pMOhly2 revealed efficient secretion of hemolysin in vitro. After formulation according to a process suitable for commercial production of Salmonella-based live bacterial vaccines, plasmids were shown to be stable in Ty21a and hemolysin secretion was demonstrated even after storage of the strains under real-time and stress conditions. After intranasal immunization of mice with S. typhi Ty21a/pANN202-812 plasmids are stable in vivo, and immunization induced a profound immune response against the heterologous HlyA antigen. Therefore, the combination of the hemolysin secretion system and S. typhi Ty21a could form the basis for a new generation of live bacterial vaccines. PMID:15595386

  1. Membrane and envelope virus proteins co-expressed as lysosome associated membrane protein (LAMP fused antigens: a potential tool to develop DNA vaccines against flaviviruses

    Directory of Open Access Journals (Sweden)

    Rafael Dhalia

    2009-12-01

    Full Text Available Vaccination is the most practical and cost-effective strategy to prevent the majority of the flavivirus infection to which there is an available vaccine. However, vaccines based on attenuated virus can potentially promote collateral side effects and even rare fatal reactions. Given this scenario, the developent of alternative vaccination strategies such as DNA-based vaccines encoding specific flavivirus sequences are being considered. Endogenous cytoplasmic antigens, characteristically plasmid DNA-vaccine encoded, are mainly presented to the immune system through Major Histocompatibility Complex class I - MHC I molecules. The MHC I presentation via is mostly associated with a cellular cytotoxic response and often do not elicit a satisfactory humoral response. One of the main strategies to target DNA-encoded antigens to the MHC II compartment is expressing the antigen within the Lysosome-Associated Membrane Protein (LAMP. The flavivirus envelope protein is recognized as the major virus surface protein and the main target for neutralizing antibodies. Different groups have demonstrated that co-expression of flavivirus membrane and envelope proteins in mammalian cells, fused with the carboxyl-terminal of LAMP, is able to induce satisfactory levels of neutralizing antibodies. Here we reviewed the use of the envelope flavivirus protein co-expression strategy as LAMP chimeras with the aim of developing DNA vaccines for dengue, West Nile and yellow fever viruses.A vacinação é a estratégia mais prática e o melhor custo-benefício para prevenir a maioria das infecções dos flavivirus, para os quais existe vacina disponível. Entretanto, as vacinas baseadas em vírus atenuados podem potencialmente promover efeitos colaterais e, mais raramente, reações fatais. Diante deste cenário, o desenvolvimento de estratégias alternativas de vacinação, como vacinas baseadas em DNA codificando seqüências específicas dos flavivirus, está sendo considerado

  2. Silencing B7-H1 enhances the anti-tumor effect of bladder cancer antigen-loaded dendritic cell vaccine in vitro

    Directory of Open Access Journals (Sweden)

    Wang S

    2014-08-01

    Full Text Available Shuo Wang,1 Yonghua Wang,1 Jing Liu,2 Shixiu Shao,1 Xianjun Li,1 Jiannan Gao,1 Haitao Niu,1 Xinsheng Wang1 1Department of Urology, 2Department of Pediatrics, The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China Objective: The aim of this study was to examine whether short hairpin RNA (shRNA expressing lentiviral particles targeting B7-H1 infection could result in B7-H1 knockdown on dendritic cells (DCs and to investigate whether B7-H1 silencing could augment the immune function of DCs and further elicit a more potent anti-tumor immune effect against bladder cancer cells in vitro. Methods: Monocyte-derived DCs, which were generated from peripheral blood mononuclear cells, were infected by a recombinant lentivirus containing shRNA sequence aimed at B7-H1. After that, the infected DCs were pulsed by tumor antigens and used to stimulate cytotoxic T lymphocytes-based anti-tumor effect in vitro. Results: The lentivirus-mediated shRNA delivery method efficiently and effectively silenced B7-H1 in DCs. Furthermore, the B7-H1 silencing enhanced the stimulatory capacity and the secretion of interleukin-12, but down-regulated interleukin-10 secretion. And more importantly, the anti-tumor effect of bladder cancer antigen-loaded DC vaccine in vitro was also potentially augmented. Conclusion: This study suggests that a combination of B7-H1 knockdown and target antigen delivery could augment anti-tumor effects in vitro, which potentially provides a novel strategy in the immunotherapy of bladder cancer. Keywords: B7-H1, bladder cancer, dendritic cell, vaccine, immunotherapy

  3. Naturally acquired immune responses to malaria vaccine candidate antigens MSP3 and GLURP in Guahibo and Piaroa indigenous communities of the Venezuelan Amazon

    Directory of Open Access Journals (Sweden)

    Baumann Andreas

    2012-02-01

    Full Text Available Abstract Background Malaria transmission in most of Latin America can be considered as controlled. In such a scenario, parameters of baseline immunity to malaria antigens are of specific interest with respect to future malaria eradication efforts. Methods A cross-sectional study was carried out in two indigenous population groups in Amazonas/Venezuela. Data from the regional malaria documentation system were extracted and participants from the ethnic groups of the Guahibo (n = 180 and Piaroa (n = 295 were investigated for the presence of Plasmodium parasites and naturally acquired antibodies to Plasmodium falciparum antigens in serum. The GMZ2 vaccine candidate proteins MSP3 and GLURP were chosen as serological markers. Results The incidence of P. falciparum in both communities was found to be less than 2%, and none of the participants harboured P. falciparum at the time of the cross-sectional. Nearly a quarter of the participants (111/475; 23,4% had positive antibody titres to at least one of the antigens. 53/475 participants (11.2% were positive for MSP3, and 93/475 participants (19.6% were positive for GLURP. High positive responses were detected in 36/475 participants (7.6% and 61/475 participants (12.8% for MSP3 and GLURP, respectively. Guahibo participants had significantly higher antibody titres than Piaroa participants. Conclusions Considering the low incidence of P. falciparum, submicroscopical infections may explain the comparatively high anti-P. falciparum antibody concentrations.

  4. Improvement of the live vaccine strain Salmonella enterica serovar Typhi Ty21a for antigen delivery via the hemolysin secretion system of Escherichia coli.

    Science.gov (United States)

    Hotz, Christian; Fensterle, Joachim; Goebel, Werner; Meyer, Susanne R; Kirchgraber, Gabriel; Heisig, Martin; Fürer, Andreas; Dietrich, Guido; Rapp, Ulf R; Gentschev, Ivaylo

    2009-02-01

    The attenuated Salmonella enterica serovar Typhi strain Ty21a (Ty21a) is the only attenuated live oral vaccine against typhoid fever. Ty21a is also an attractive carrier for the delivery of heterologous antigens. We have used Ty21a for antigen delivery via the hemolysin (HlyA) secretion system of Escherichia coli, the prototype of the type I secretion system (T1SS). In this study, we identified by genetic complementation that the specific mutation of rpoS correlated with the hemolysin production of strain Ty21a. We furthermore showed that complementation with a plasmid encoding rfaH, which is described to be a downstream target of rpoS, led to increased expression and secretion of hemolysin. Finally, we demonstrated a significant enhancement of antibody responses against the heterologous HlyA antigen of Ty21a after immunization of mice with rfaH complemented S. typhi strain secreting HlyA compared with the same strain without rfaH plasmid. PMID:18706861

  5. A Novel Virus-Like Particle Based Vaccine Platform Displaying the Placental Malaria Antigen VAR2CSA

    OpenAIRE

    Thrane, Susan; Janitzek, Christoph M.; Agerbæk, Mette Ø.; Ditlev, Sisse B.; Resende, Mafalda; Nielsen, Morten A.; Theander, Thor G.; Salanti, Ali; Sander, Adam F.

    2015-01-01

    Placental malaria caused by Plasmodium falciparum is a major cause of mortality and severe morbidity. Clinical testing of a soluble protein-based vaccine containing the parasite ligand, VAR2CSA, has been initiated. VAR2CSA binds to the human receptor chondroitin sulphate A (CSA) and is responsible for sequestration of Plasmodium falciparum infected erythrocytes in the placenta. It is imperative that a vaccine against malaria in pregnancy, if administered to women before they become pregnant, ...

  6. Vaccine-induced plasmablast responses in rhesus macaques: phenotypic characterization and a source for generating antigen-specific monoclonal antibodies

    OpenAIRE

    Silveira, Eduardo L. V.; Kasturi, Sudhir P.; Kovalenkov, Yevgeniy; Ur Rasheed, Ata; Yeiser, Patryce; Jinnah, Zarpheen S.; Legere, Traci H.; Pulendran, Bali; Villinger, Francois; Wrammert, Jens

    2014-01-01

    Over 100 broadly neutralizing antibodies have been isolated from a minority of HIV infected patients, but the steps leading to the selection of plasmacells producing such antibodies remain incompletely understood, hampering the development of vaccines able to elicit them. Rhesus macaques have become a preferred animal model system used to study SIV/HIV, for the characterization and development of novel therapeutics and vaccines as well as to understand pathogenesis. However, most of our knowl...

  7. Significance of Response to Hepatitis B Recombinant Vaccine in Subjects with Isolated Antibody to Hepatitis B Core Antigen

    OpenAIRE

    Bahari, Ali; Izadi, Shahrokh; Bari, Zohreh; Khosravi, Soheyla; Baghaei, Bita; Saneimoghadam, Esmaeil; Firouzi, Farzad; Espiari, Ali; Esmaeilzadeh, Abbas; Mokhtarifar, Ali; Bakhshipour, Alireza; Ganji, Azita

    2015-01-01

    BACKGROUND It is important to differentiate whether isolated anti-HBc is due to false positive results or the prior exposure to hepatitis B virus, because individuals with false-positive anti-HBc can benefit from vaccination and their blood can be safely transfused. To distinguish between these two conditions, we evaluated the serologic response to hepatitis B vaccine. METHODS Ninety subjects with isolated anti-HBc (cases) and 100 subjects with totally negative hepatitis B serologic markers (...

  8. Freeze-Drying of Plant Tissue Containing HBV Surface Antigen for the Oral Vaccine against Hepatitis B

    OpenAIRE

    2014-01-01

    The aim of this study was to develop a freeze-drying protocol facilitating successful processing of plant material containing the small surface antigen of hepatitis B virus (S-HBsAg) while preserving its VLP structure and immunogenicity. Freeze-drying of the antigen in lettuce leaf tissue, without any isolation or purification step, was investigated. Each process step was consecutively evaluated and the best parameters were applied. Several drying profiles and excipients were tested. The prof...

  9. Montanide™ ISA 71 VG adjuvant enhances antibody and cell-mediated immune responses to profilin subunit antigen vaccination and promotes protection against Eimeria acervulina and Eimeria tenella. Experimental Parasitology

    Science.gov (United States)

    The present study was conducted to investigate the immunoenhancing effects of MontanideTM ISA 71 VG adjuvant on profilin subunit antigen vaccination. Broiler chickens were immunized subcutaneously with a purified Eimeria acervulina recombinant profilin protein, either alone or mixed with ISA 71 VG, ...

  10. Live recombinant Salmonella Typhi vaccines constructed to investigate the role of rpoS in eliciting immunity to a heterologous antigen.

    Science.gov (United States)

    Shi, Huoying; Santander, Javier; Brenneman, Karen E; Wanda, Soo-Young; Wang, Shifeng; Senechal, Patti; Sun, Wei; Roland, Kenneth L; Curtiss, Roy

    2010-01-01

    We hypothesized that the immunogenicity of live Salmonella enterica serovar Typhi vaccines expressing heterologous antigens depends, at least in part, on its rpoS status. As part of our project to develop a recombinant attenuated S. Typhi vaccine (RASTyV) to prevent pneumococcal diseases in infants and children, we constructed three RASTyV strains synthesizing the Streptococcus pneumoniae surface protein PspA to test this hypothesis. Each vector strain carried ten engineered mutations designed to optimize safety and immunogenicity. Two S. Typhi vector strains (chi9639 and chi9640) were derived from the rpoS mutant strain Ty2 and one (chi9633) from the RpoS(+) strain ISP1820. In chi9640, the nonfunctional rpoS gene was replaced with the functional rpoS gene from ISP1820. Plasmid pYA4088, encoding a secreted form of PspA, was moved into the three vector strains. The resulting RASTyV strains were evaluated for safety in vitro and for immunogenicity in mice. All three RASTyV strains were similar to the live attenuated typhoid vaccine Ty21a in their ability to survive in human blood and human monocytes. They were more sensitive to complement and were less able to survive and persist in sewage and surface water than their wild-type counterparts. Adult mice intranasally immunized with any of the RASTyV strains developed immune responses against PspA and Salmonella antigens. The RpoS(+) vaccines induced a balanced Th1/Th2 immune response while the RpoS(-) strain chi9639(pYA4088) induced a strong Th2 immune response. Immunization with any RASTyV provided protection against S. pneumoniae challenge; the RpoS(+) strain chi9640(pYA4088) provided significantly greater protection than the ISP1820 derivative, chi9633(pYA4088). In the pre-clinical setting, these strains exhibited a desirable balance between safety and immunogenicity and are currently being evaluated in a Phase 1 clinical trial to determine which of the three RASTyVs has the optimal safety and immunogenicity profile

  11. Lysosome-associated membrane glycoprotein (LAMP)--preliminary study on a hidden antigen target for vaccination against schistosomiasis.

    Science.gov (United States)

    Nawaratna, Sujeevi S K; Gobert, Geoffrey N; Willis, Charlene; Mulvenna, Jason; Hofmann, Andreas; McManus, Donald P; Jones, Malcolm K

    2015-01-01

    Our previously reported gene atlasing of schistosome tissues revealed transcripts that were highly enriched in the digestive tract of Schistosoma mansoni. From these, we selected two candidates, Sm-LAMP and Sm-NPC2 for testing as vaccine targets. The two molecules were selected on the basis of relatively high expression in the gastrodermis, their potentially important biological function, divergence from homologous molecules of the host and possible apical membrane expression in the gastrodermis. Bacterially expressed recombinant peptides corresponding to regions excluding trans-membrane domains of the selected vaccine targets were used in blinded vaccine trials in CBA mice using alum-CpG as adjuvant. Vaccine trials using the recombinant insoluble Sm-LAMP protein showed 16-25% significant reduction in total worm burden. Faecal egg count reduction was 52% and 60% in two trials, respectively, with similar results for the solubly expressed protein. Liver egg burden was reduced significantly (20% and 38%) with an insoluble recombinant Sm-LAMP in two trials, but not with the soluble recombinant form. Parasite fecundity was not affected by either Sm-LAMP protein preparations in the trials. It is concluded that Sm-LAMP may provide limited protection towards S. mansoni infections but could be used in combination with other vaccine candidates, to provide more comprehensive protection. PMID:26472258

  12. Vaccine Adjuvants in Fish Vaccines Make a Difference: Comparing Three Adjuvants (Montanide ISA763A Oil, CpG/Poly I:C Combo and VHSV Glycoprotein) Alone or in Combination Formulated with an Inactivated Whole Salmonid Alphavirus Antigen.

    Science.gov (United States)

    Thim, Hanna L; Villoing, Stéphane; McLoughlin, Marian; Christie, Karen Elina; Grove, Søren; Frost, Petter; Jørgensen, Jorunn B

    2014-01-01

    Most commercial vaccines offered to the aquaculture industry include inactivated antigens (Ag) formulated in oil adjuvants. Safety concerns are related to the use of oil adjuvants in multivalent vaccines for fish, since adverse side effects (e.g., adhesions) can appear. Therefore, there is a request for vaccine formulations for which protection will be maintained or improved, while the risk of side effects is reduced. Here, by using an inactivated salmonid alphavirus (SAV) as the test Ag, the combined use of two Toll-like receptor (TLR) ligand adjuvants, CpG oligonucleotides (ODNs) and poly I:C, as well as a genetic adjuvant consisting of a DNA plasmid vector expressing the viral haemorrhagic septicaemia virus (VHSV) glycoprotein (G) was explored. VHSV-G DNA vaccine was intramuscularly injected in combination with intraperitoneal injection of either SAV Ag alone or combined with the oil adjuvant, Montanide ISA763, or the CpG/polyI:C combo. Adjuvant formulations were evaluated for their ability to boost immune responses and induce protection against SAV in Atlantic salmon, following cohabitation challenge. It was observed that CpG/polyI:C-based formulations generated the highest neutralizing antibody titres (nAbs) before challenge, which endured post challenge. nAb responses for VHSV G-DNA- and oil-adjuvanted formulations were marginal compared to the CpG/poly I:C treatment. Interestingly, heat-inactivated sera showed reduced nAb titres compared to their non-heated counterparts, which suggests a role of complement-mediated neutralization against SAV. Consistently elevated levels of innate antiviral immune genes in the CpG/polyI:C injected groups suggested a role of IFN-mediated responses. Co-delivery of the VHSV-G DNA construct with either CpG/polyI:C or oil-adjuvanted SAV vaccine generated higher CD4 responses in head kidney at 48 h compared to injection of this vector or SAV Ag alone. The results demonstrate that a combination of pattern recognizing receptor (PRR

  13. Vaccine Adjuvants in Fish Vaccines Make a Difference: Comparing Three Adjuvants (Montanide ISA763A Oil, CpG/Poly I:C Combo and VHSV Glycoprotein Alone or in Combination Formulated with an Inactivated Whole Salmonid Alphavirus Antigen

    Directory of Open Access Journals (Sweden)

    Hanna L. Thim

    2014-03-01

    Full Text Available Most commercial vaccines offered to the aquaculture industry include inactivated antigens (Ag formulated in oil adjuvants. Safety concerns are related to the use of oil adjuvants in multivalent vaccines for fish, since adverse side effects (e.g., adhesions can appear. Therefore, there is a request for vaccine formulations for which protection will be maintained or improved, while the risk of side effects is reduced. Here, by using an inactivated salmonid alphavirus (SAV as the test Ag, the combined use of two Toll-like receptor (TLR ligand adjuvants, CpG oligonucleotides (ODNs and poly I:C, as well as a genetic adjuvant consisting of a DNA plasmid vector expressing the viral haemorrhagic septicaemia virus (VHSV glycoprotein (G was explored. VHSV-G DNA vaccine was intramuscularly injected in combination with intraperitoneal injection of either SAV Ag alone or combined with the oil adjuvant, Montanide ISA763, or the CpG/polyI:C combo. Adjuvant formulations were evaluated for their ability to boost immune responses and induce protection against SAV in Atlantic salmon, following cohabitation challenge. It was observed that CpG/polyI:C-based formulations generated the highest neutralizing antibody titres (nAbs before challenge, which endured post challenge. nAb responses for VHSV G-DNA- and oil-adjuvanted formulations were marginal compared to the CpG/poly I:C treatment. Interestingly, heat-inactivated sera showed reduced nAb titres compared to their non-heated counterparts, which suggests a role of complement-mediated neutralization against SAV. Consistently elevated levels of innate antiviral immune genes in the CpG/polyI:C injected groups suggested a role of IFN-mediated responses. Co-delivery of the VHSV-G DNA construct with either CpG/polyI:C or oil-adjuvanted SAV vaccine generated higher CD4 responses in head kidney at 48 h compared to injection of this vector or SAV Ag alone. The results demonstrate that a combination of pattern recognizing

  14. Antibody levels to multiple malaria vaccine candidate antigens in relation to clinical malaria episodes in children in the Kasena-Nankana district of Northern Ghana

    Directory of Open Access Journals (Sweden)

    Oduro Abraham R

    2011-05-01

    Full Text Available Abstract Background Considering the natural history of malaria of continued susceptibility to infection and episodes of illness that decline in frequency and severity over time, studies which attempt to relate immune response to protection must be longitudinal and have clearly specified definitions of immune status. Putative vaccines are expected to protect against infection, mild or severe disease or reduce transmission, but so far it has not been easy to clearly establish what constitutes protective immunity or how this develops naturally, especially among the affected target groups. The present study was done in under six year old children to identify malaria antigens which induce antibodies that correlate with protection from Plasmodium falciparum malaria. Methods In this longitudinal study, the multiplex assay was used to measure IgG antibody levels to 10 malaria antigens (GLURP R0, GLURP R2, MSP3 FVO, AMA1 FVO, AMA1 LR32, AMA1 3D7, MSP1 3D7, MSP1 FVO, LSA-1and EBA175RII in 325 children aged 1 to 6 years in the Kassena Nankana district of northern Ghana. The antigen specific antibody levels were then related to the risk of clinical malaria over the ensuing year using a negative binomial regression model. Results IgG levels generally increased with age. The risk of clinical malaria decreased with increasing antibody levels. Except for FMPOII-LSA, (p = 0.05, higher IgG levels were associated with reduced risk of clinical malaria (defined as axillary temperature ≥37.5°C and parasitaemia of ≥5000 parasites/ul blood in a univariate analysis, upon correcting for the confounding effect of age. However, in a combined multiple regression analysis, only IgG levels to MSP1-3D7 (Incidence rate ratio = 0.84, [95% C.I.= 0.73, 0.97, P = 0.02] and AMA1 3D7 (IRR = 0.84 [95% C.I.= 0.74, 0.96, P = 0.01] were associated with a reduced risk of clinical malaria over one year of morbidity surveillance. Conclusion The data from this study support the view

  15. Clearing Persistent Extracellular Antigen of Hepatitis B Virus: An Immunomodulatory Strategy To Reverse Tolerance for an Effective Therapeutic Vaccination.

    Science.gov (United States)

    Zhu, Danming; Liu, Longchao; Yang, Dan; Fu, Sherry; Bian, Yingjie; Sun, Zhichen; He, Junming; Su, Lishan; Zhang, Liguo; Peng, Hua; Fu, Yang-Xin

    2016-04-01

    Development of therapeutic vaccines/strategies to control chronic hepatitis B virus (HBV) infection has been challenging because of HBV-induced tolerance. In this study, we explored strategies for breaking tolerance and restoring the immune response to the HBV surface Ag in tolerant mice. We demonstrated that immune tolerance status is attributed to the level and duration of circulating HBsAg in HBV carrier models. Removal of circulating HBsAg by a monoclonal anti-HBsAg Ab in tolerant mice could gradually reduce tolerance and reestablish B cell and CD4(+) T cell responses to subsequent Engerix-B vaccination, producing protective IgG. Furthermore, HBsAg-specific CD8(+) T cells induced by the addition of a TLR agonist resulted in clearance of HBV in both serum and liver. Thus, generation of protective immunity can be achieved by clearing extracellular viral Ag with neutralizing Abs followed by vaccination. PMID:26936879

  16. MHC class II-associated invariant chain linkage of antigen dramatically improves cell-mediated immunity induced by adenovirus vaccines

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Mandrup Jensen, Camilla Maria; Orskov, Cathrine; Thomsen, Allan Randrup; Christensen, Jan Pravsgaard; Sørensen, Maria Rathmann

    2008-01-01

    potent and versatile Ag delivery vehicles available. However, the impact of chronic infections like HIV and hepatitis C virus underscore the need for further improvements. In this study, we show that the protective immune response to an adenovirus-encoded vaccine Ag can be accelerated, enhanced......, broadened, and prolonged by tethering of the rAg to the MHC class II-associated invariant chain (Ii). Thus, adenovirus-vectored vaccines expressing lymphocytic choriomeningitis virus (LCMV)-derived glycoprotein linked to Ii increased the CD4+ and CD8+ T cell stimulatory capacity in vitro and in vivo....... Furthermore, mice vaccinated with a single dose of adenovirus-expressing LCMV-derived glycoprotein linked to Ii were protected against lethal virus-induced choriomeningitis, lethal challenge with strains mutated in immunodominant T cell epitopes, and systemic infection with a highly invasive strain. In...

  17. Oral antigen exposure in newborn piglets circumvents induction of oral tolerance in response to intraperitoneal vaccination in later life

    OpenAIRE

    Pasternak, J. Alex; Ng, Siew Hon; Buchanan, Rachelle M; Mertins, Sonja; Mutwiri, George K; Gerdts, Volker; Wilson, Heather L.

    2015-01-01

    Background We previously determined that newborn piglets orally gavaged with Ovalbumin (OVA) responded to systemic OVA re-exposure with tolerance; if adjuvants were included in oral vaccine, piglets responded with antibody-mediated immunity (Vet Immunol Immunopathol 161(3–4):211–21, 2014). Here, we will investigate whether newborn piglets gavaged with a vaccine comprised of OVA plus unmethylated CpG oligodeoxynucleotides (CpG; soluble component; OVA/CpG) combined with OVA plus CpG encapsulate...

  18. Pellet feed adsorbed with the recombinant Lactococcus lactis BFE920 expressing SiMA antigen induced strong recall vaccine effects against Streptococcus iniae infection in olive flounder (Paralichthys olivaceus).

    Science.gov (United States)

    Kim, Daniel; Beck, Bo Ram; Lee, Sun Min; Jeon, Jongsu; Lee, Dong Wook; Lee, Jae Il; Song, Seong Kyu

    2016-08-01

    The aim of this study was to develop a fish feed vaccine that provides effective disease prevention and convenient application. A lactic acid bacterium (LAB), Lactococcus lactis BFE920, was modified to express the SiMA antigen, a membrane protein of Streptococcus iniae. The antigen was engineered to be expressed under the nisin promoter, which is induced by nisin produced naturally by the host LAB. Various sizes (40 ± 3.5 g, 80 ± 2.1 g, and 221 ± 2.4 g) of olive flounder (Paralichthys olivaceus) were vaccinated by feeding the extruded pellet feed, onto which the SiMA-expressing L. lactis BFE920 (1.0 × 10(7) CFU/g) was adsorbed. Vaccine-treated feed was administered twice a day for 1 week, and priming and boosting were performed with a 1-week interval in between. The vaccinated fish had significantly elevated levels of antigen-specific serum antibodies and T cell marker mRNAs: CD4-1, CD4-2, and CD8a. In addition, the feed vaccine significantly induced T cell effector functions, such as the production of IFN-γ and activation of the transcription factor that induces its expression, T-bet. When the flounder were challenged by intraperitoneal infection and bath immersion with S. iniae, the vaccinated fish showed 84% and 82% relative percent survival (RPS), respectively. Furthermore, similar protective effects were confirmed even 3 months after vaccination in a field study (n = 4800), indicating that this feed vaccine elicited prolonged duration of immunopotency. In addition, the vaccinated flounder gained 21% more weight and required 16% less feed to gain a unit of body weight compared to the control group. The data clearly demonstrate that the L. lactis BFE920-SiMA feed vaccine has strong protective effects, induces prolonged vaccine efficacy, and has probiotic effects. In addition, this LAB-based fish feed vaccine can be easily used to target many different pathogens of diverse fish species. PMID:27302864

  19. Affordable Care Act (ACA)

    Data.gov (United States)

    Social Security Administration — The Affordable Care Act (ACA) is a federal statute enacted with a goal of increasing the quality and affordability of health insurance. Through a web service, CMS...

  20. Immunoprotective activity of a Salmonid Alphavirus Vaccine: comparison of the immune responses induced by inactivated whole virus antigen formulations based on CpG class B oligonucleotides and poly I:C alone or combined with an oil adjuvant.

    Science.gov (United States)

    Thim, Hanna L; Iliev, Dimitar B; Christie, Karen E; Villoing, Stéphane; McLoughlin, Marian F; Strandskog, Guro; Jørgensen, Jorunn B

    2012-07-01

    CpG oligonucleotides and polyinosinic:polycytidylic acid (poly I:C) are toll-like receptor (TLR) agonists that mimic the immunostimulatory properties of bacterial DNA and double-stranded viral RNA respectively, and which have exhibited potential to serve as vaccine adjuvants in previous experiments. Here, a combination of CpGs and poly I:C together with water- or oil-formulated Salmonid Alphavirus (SAV) antigen preparations has been used for a vaccine in Atlantic salmon and tested for protection in SAV challenge trial. The results demonstrate that vaccination with a high dose of the SAV antigen induced protection against challenge with SAV which correlated with production of neutralizing antibodies (NAbs). As the high antigen dose alone induced full protection, no beneficial effect from the addition of CpG and poly I:C could be observed. Nevertheless, these TLR ligands significantly enhanced the levels of NAbs in serum of vaccinated fish. Interestingly, gene expression analysis demonstrated that while addition of oil suppressed the CpG/poly I:C-induced expression of IFN-γ, the upregulation of IFNa1 was substantially enhanced. A low dose of the SAV antigen combined with oil did not induce any detectable levels of NAbs either with or without TLR ligands present, however the addition of CpG and poly I:C to the low SAV antigen dose formulation significantly enhanced the protection against SAV suggesting that CpG/poly I:C may have enhanced a cytotoxic response - a process which is dependent on the up-regulation of type I IFN. These results highlight the immunostimulatory properties of the tested TLR ligands and will serve as a ground for further, more detailed studies aimed to investigate their capacity to serve as adjuvants in vaccine formulations for Atlantic salmon. PMID:22634299

  1. Evaluacion de la tecnica de contraimmunoelectroforesis para determinar la potencia antigena de las vacunas antirrabicas Evaluation ot the counterimmunoelectrophoresis technique to determine the antigenic potency of antirrabic vaccines

    Directory of Open Access Journals (Sweden)

    Graciela Miceli

    1993-12-01

    paper presents the results obtained when using a counterimmunoelectrophoresis (CIE techniques to determine the antigens content in samples of 84 and 40 samples of lots of suckling mouse rabies and tissue culture rabies vaccines, respectively. The evaluation of rabies vaccines under, at, near and up to 0.3 UI by the NIH and CIE tests showed that for practical use, a CIE titer of 1:4 would match the minimum of NIH potency test requirement. Low degree of CIE test variability within our laboratory was observed, when two working reference and 7 lots of rabies vaccines from different origin and activity were tested in five independent assays. All titres fell within one double dilution what is an indication of its reproducibility. Good sensitivity to detect antigen deterioration in thermal degradation test was observed when samples of 3 lots of liquid suckling mouse rabies vaccine were held stored at 4ºC or at 37ºC for 4 weeks and assays by CIE and NIH tests. Finally, CIE test could apply by manufactures to follow the concentration procedures to determine the final end point which could match a desired antigenic value in the NIH potency test.

  2. Genome sequence of Corynebacterium pseudotuberculosis biovar equi strain 258 and prediction of antigenic targets to improve biotechnological vaccine production

    DEFF Research Database (Denmark)

    Soares, Siomar C; Trost, Eva; Ramos, Rommel T J;

    2013-01-01

    Corynebacterium pseudotuberculosis is the causative agent of several veterinary diseases in a broad range of economically important hosts, which can vary from caseous lymphadenitis in sheep and goats (biovar ovis) to ulcerative lymphangitis in cattle and horses (biovar equi). Existing vaccines ag...

  3. Significance of isolated antibody to hepatitis B core antigen in Dutch national vaccination campaign of behavioural high-risk groups

    NARCIS (Netherlands)

    R.P.M. Koene; H.M. Gotz; J.A.R. van den Hoek; M.L.A. Heijnen; J.A. van Steenbergen; A.C.M. Kroes

    2009-01-01

    In the Dutch national vaccination campaign for behavioural risk groups, anti-HBcore is used as the primary HBV screening test. Samples with positive results undergo testing for active infection (HBsAg) but are otherwise accepted as indicating past infection, thereby assuming immunity. This study eva

  4. Enhancement of Leishmania amazonensis infection in BCG non-responder mice by BCG-antigen specific vaccine

    Directory of Open Access Journals (Sweden)

    Kátia da Silva Calabrese

    1992-01-01

    Full Text Available Different patterns of cutaneous leishmaniasis can be induced when a challenge of alike dose of Leishmania amazonensis amastigotes in various inbred strains was applied. Two strains of mice, the Balb/c and C57 BL/10J, showed exceptional suscepbility, and 10(elevado a sexta potência amastigotes infective dose lead, to ulcerative progressive lesions with cutaneous metastasis and loss by necrosis of leg on wich the footpad primary lesion occured. Lesions were also progressive but in a lower degree when C3H/HeN and C57BL/6 were infected. Lesions progress slowly in DBA/2 mice presenting lesions wich reach a discreet peack after 12 weeks, do not heal but do not uncerate. DBA/2 mice is, therefore, a good model for immunomodualtion. In attempt to determine the influence of BCG in vaccination schedule using microsomal fraction, DBA/2 became an excellent model, since it is also a non-responder to BCG. Vaccination of DBA/2 mice, receiving the same 10(elevado a sexta potência BCG viable dose and 10 *g or 50 *g of protein content of microsomal fraction, lead to a progressive disease with time course similar to those observed in susceptible non-vaccinated C57BL/10J mice after 6 months of observation. An enhancement of infection in BCG non-responder mice suggests that use of BCG as immunostimulant in humans could be critical for both vaccination and immunoprophylactic strategies.

  5. ANTIBODIES TO EIMERIA MAXIMA GAMETOCYTE ANTIGENS CROSS-REACT WITH EIMERIA TENELLA AND E. ACERVULINA: IMPLICATIONS FOR VACCINE DEVELOPMENT

    Science.gov (United States)

    It has been shown previously that vaccination with gamete specific molecules in Eimeria maxima offers protection via transfer of maternal antibodies (anti-EmAPGA), not just against infection with E. maxima, but also against E. tenella and E. acervulina. Antibodies to the gamete proteins recognise t...

  6. Oral vaccination of fish

    OpenAIRE

    Embregts, Carmen W.E.; Forlenza, Maria

    2016-01-01

    The limited number of oral vaccines currently approved for use in humans and veterinary species clearly illustrates that development of efficacious and safe oral vaccines has been a challenge not only for fish immunologists. The insufficient efficacy of oral vaccines is partly due to antigen breakdown in the harsh gastric environment, but also to the high tolerogenic gut environment and to inadequate vaccine design. In this review we discuss current approaches used to develop oral vaccines fo...

  7. The testing of antibodies raised against poultry red mite antigens in an in vitro feeding assay; preliminary screen for vaccine candidates.

    Science.gov (United States)

    Wright, Harry W; Bartley, Kathryn; Nisbet, Alasdair J; McDevitt, Regina M; Sparks, Nickolas H C; Brocklehurst, Sarah; Huntley, John F

    2009-06-01

    Dermanyssus gallinae (De Geer), the poultry red mite, is a blood-feeding ectoparasite that infests many bird species. We have used an in vitro feeding assay to allow the identification of protective D. gallinae antigens that may have potential as vaccine candidates. Homogenised mites were extracted sequentially with PBS, Tween 20, Triton X100 and urea giving four protein fractions. Five experimental groups of Lohmann Brown hens were used to generate antibodies; four groups were injected with one of each of the protein fractions in QuilA adjuvant and a control group was injected with adjuvant only. Booster injections were administered 2 and 4 weeks after initial immunisation. Eggs were collected throughout the experiment and soluble IgY antibodies were extracted from a pool of egg yolks collected at week six post-injection. Western blots, performed using post vaccination antibodies from test and control groups, revealed a strong antibody response against a range of injected proteins. Fresh chicken blood, supplemented with antibodies raised against these protein fractions, was fed to mites in an in vitro feeding assay in order to determine whether the antibodies had an anti-mite effect. Although there was variability in the numbers of feeding mites, it was found that the strongest anti-mite effect was seen with the PBS protein fraction, which had a cumulative average mortality of 34.8% 14 days after feeding compared with 27.3% for the control group (P = 0.043). PMID:19184466

  8. Core-linked LPS expression of Shigella dysenteriae serotype 1 O-antigen in live Salmonella Typhi vaccine vector Ty21a: preclinical evidence of immunogenicity and protection.

    Science.gov (United States)

    Xu, De Qi; Cisar, John O; Osorio, Manuel; Wai, Tint T; Kopecko, Dennis J

    2007-08-14

    Shigella dysenteriae serotype 1 (S. dysenteriae 1) causes severe shigellosis that is typically associated with high mortality. Antibodies against Shigella serotype-specific O-polysaccharide (O-Ps) have been shown to be host protective. In this study, the rfb locus and the rfp gene with their cognate promoter regions were PCR-amplified from S. dysenteriae 1, cloned, and sequenced. Deletion analysis showed that eight rfb ORFs plus rfp are necessary for biosynthesis of this O-Ps. A tandemly-linked rfb-rfp gene cassette was cloned into low copy plasmid pGB2 to create pSd1. Avirulent Salmonella enterica serovar Typhi (S. Typhi) Ty21a harboring pSd1 synthesized S. Typhi 9, 12 LPS as well as typical core-linked S. dysenteriae 1 LPS. Animal immunization studies showed that Ty21a (pSd1) induces protective immunity against high stringency challenge with virulent S. dysenteriae 1 strain 1617. These data further demonstrate the utility of S. Typhi Ty21a as a live, bacterial vaccine delivery system for heterologous O-antigens, supporting the promise of a bifunctional oral vaccine for prevention of shigellosis and typhoid fever. PMID:17629369

  9. A novel recombinant bivalent outer membrane protein of Vibrio vulnificus and Aeromonas hydrophila as a vaccine antigen of American eel (Anguilla rostrata).

    Science.gov (United States)

    SongLin, Guo; PanPan, Lu; JianJun, Feng; JinPing, Zhao; Peng, Lin; LiHua, Duan

    2015-04-01

    The immogenicity of a novel vaccine antigen was evaluated after immunized American eels (Anguilla rostrata) with a recombinant bivalent expressed outer membrane protein (OMP) of Vibrio vulnificus and Aeromonas hydrophila. Three groups of eels were intraperitoneal (i.p) injected with phosphate-buffered saline (PBS group), formaline-killed-whole-cell (FKC) of A. hydrophila and V. vulnificus (FKC group) or the bivalent OMP (OMP group). On 14, 21, 28 and 42 days post-vaccination respectively, proliferation of the whole blood cells, titers of specific antibody and lysozyme activities of experimental eels were detected. On 28 day post-vaccination, eels from three groups were challenged by i.p injection of live A. hydrophila or V. vulnificus. The results showed that, compared with the PBS group, proliferation of whole blood cells in OMP group was significant enhanced on 28 days, and the serum titers of anti-A.hydrophila and anti-V. vulnificus antibody in eels of FKC and OMP group were significant increased on 14, 21 and 28d. Lysozyme Activities in serum, skin mucus, liver and kidney were significant changed between the three groups. Relative Percent Survival (RPS) after challenged A. hydrophila in KFC vs. PBS group and OMP vs. PBS group were 62.5% and 50% respectively, and the RPS challenged V. vulnificus in FKC and OMP vs. PBS group were 37.5% and 50% respectively. These results suggest that American eels immunized with the bivalent OMP would positively affect specific as well as non-specific immune parameters and protect against infection by the two pathogens in fresh water farming. PMID:25655329

  10. Multicenter, phase II clinical trial of cancer vaccination for advanced esophageal cancer with three peptides derived from novel cancer-testis antigens

    Directory of Open Access Journals (Sweden)

    Kono Koji

    2012-07-01

    Full Text Available Abstract Background Since a phase I clinical trial using three HLA-A24-binding peptides from TTK protein kinase (TTK, lymphocyte antigen-6 complex locus K (LY6K, and insulin-like growth factor-II mRNA binding protein-3 (IMP3 had been shown to be promising for esophageal squamous cell carcinoma (ESCC, we further performed a multicenter, non-randomized phase II clinical trial. Patients and methods Sixty ESCC patients were enrolled to evaluate OS, PFS, immunological response employing ELISPOT and pentamer assays. Each of the three peptides was administered with IFA weekly. All patients received the vaccination without knowing an HLA-A type, and the HLA types were key-opened at the analysis point. Hence, the endpoints were set to evaluate differences between HLA-A*2402-positive (24(+ and -negative (24(− groups. Results The OS in the 24 (+ group (n = 35 tended to be better than that in the 24(− group (n = 25 (MST 4.6 vs. 2.6 month, respectively, p = 0.121, although the difference was not statistically significant. However, the PFS in the 24(+ group was significantly better than that in the 24(− group (p = 0.032. In the 24(+ group, ELISPOT assay indicated that the LY6K-, TTK-, and IMP3-specific CTL responses were observed after the vaccination in 63%, 45%, and 60% of the 24(+ group, respectively. The patients having LY6K-, TTK-, and IMP3-specific CTL responses revealed the better OS than those not having CTL induction, respectively. The patients showing the CTL induction for multiple peptides have better clinical responses. Conclusions The immune response induced by the vaccination could make the prognosis better for advanced ESCC patients. Trial registration ClinicalTrials.gov, number NCT00995358

  11. Dendritic cell-based vaccination with lentiviral vectors encoding ubiquitinated hepatitis B core antigen enhances hepatitis B virus-specific immune responses in vivo.

    Science.gov (United States)

    Dai, Shenglan; Zhuo, Meng; Song, Linlin; Chen, Xiaohua; Yu, Yongsheng; Tang, Zhenghao; Zang, Guoqing

    2015-11-01

    The activity of hepatitis B virus (HBV)-specific cytotoxic T lymphocytes (CTLs) plays a predominant role in the clearance of HBV. Dendritic cells (DCs) are key antigen-presenting cells and play an important role in the initiation of immune responses. We previously verified that lentiviral vector encoding ubiquitinated hepatitis B core antigen (LV-Ub-HBcAg) effectively transduced DCs to induce maturation, and the mature DCs efficiently induced T cell polarization to Th1 and generated HBcAg-specific CTLs ex vivo. In this study, HBV-specific immune responses of LV-Ub-HBcAg in BALB/c mice (H-2Kd) were evaluated. It was shown that direct injection of LV-Ub-HBcAg increased the production of cytokines IL-2 and IFN-γ, elicited strong antibody responses, and remarkably generated a high percentage of IFN-γ+CD8+ T cells with HBV-specific CTL responses in BALB/c mice. In addition, direct injection of LV-Ub-HBcAg induced potent anti-HBV immune responses, similar to those elicited by in vitro-transduced DCs. In conclusion, the DC-based therapeutic vaccine LV-Ub-HBcAg elicited specific antibody immune responses and induced robust specific CTL activity in vivo. PMID:26373843

  12. The Leishmania HSP20 Is Antigenic during Natural Infections, but, as DNA Vaccine, It does not Protect BALB/c Mice against Experimental L. amazonensis Infection

    Directory of Open Access Journals (Sweden)

    Ana M. Montalvo-Álvarez

    2008-01-01

    Full Text Available Protozoa of the genus Leishmania are causative agents of leishmaniasis, an important health problem in both human and veterinary medicine. Here, we describe a new heat shock protein (HSP in Leishmania, belonging to the small HSP (sHSP family in kinetoplastids. The protein is highly conserved in different Leishmania species, showing instead significant divergence with sHSP's from other organisms. The humoral response elicited against this protein during Leishmania infection has been investigated in natural infected humans and dogs, and in experimentally infected hamsters. Leishmania HSP20 is a prominent antigen for canine hosts; on the contrary, the protein seems to be a poor antigen for human immune system. Time-course analysis of appearance of anti-HSP20 antibodies in golden hamsters indicated that these antibodies are produced at late stages of the infection, when clinical symptoms of disease are patent. Finally, the protective efficacy of HSP20 was assessed in mice using a DNA vaccine approach prior to challenge with Leishmania amazonensis.

  13. Construction of a triple modified p53 containing DNA vaccine to enhance processing and presentation of the p53 antigen

    NARCIS (Netherlands)

    Hospers, Geke A. P.; Meijer, Coby; Dam, Wendy A.; Roossink, Frank; Mulder, Nanno H.

    2009-01-01

    More effective and less toxic treatments are urgently needed in the treatment of patients with cancer. The turnout suppressor protein p53 is a tumour-associated antigen that could serve that purpose when applied in an immunologic approval to cancer. It is mutated in similar to 50% of the tumours res

  14. Canonical affordances in context

    Directory of Open Access Journals (Sweden)

    Alan Costall

    2012-12-01

    Full Text Available James Gibson’s concept of affordances was an attempt to undermine the traditional dualism of the objective and subjective. Gibson himself insisted on the continuity of “affordances in general” and those attached to human artifacts. However, a crucial distinction needs to be drawn between “affordances in general” and the “canonical affordances” that are connected primarily to artifacts. Canonical affordances are conventional and normative. It is only in such cases that it makes sense to talk of the affordance of the object. Chairs, for example, are for sitting-on, even though we may also use them in many other ways. A good deal of confusion has arisen in the discussion of affordances from (1 the failure to recognize the normative status of canonical affordances and (2 then generalizing from this special case.

  15. IgG2 antibodies against a clinical grade Plasmodium falciparum CSP vaccine antigen associate with protection against transgenic sporozoite challenge in mice.

    Directory of Open Access Journals (Sweden)

    Robert Schwenk

    Full Text Available The availability of a highly purified and well characterized circumsporozoite protein (CSP is essential to improve upon the partial success of recombinant CSP-based malaria vaccine candidates. Soluble, near full-length, Plasmodium falciparum CSP vaccine antigen (CS/D was produced in E. coli under bio-production conditions that comply with current Good Manufacturing Practices (cGMP. A mouse immunogenicity study was conducted using a stable oil-in-water emulsion (SE of CS/D in combination with the Toll-Like Receptor 4 (TLR4 agonist Glucopyranosyl Lipid A (GLA/SE, or one of two TLR7/8 agonists: R848 (un-conjugated or 3M-051 (covalently conjugated. Compared to Alum and SE, GLA/SE induced higher CS/D specific antibody response in Balb/c mice. Subclass analysis showed higher IgG2:IgG1 ratio of GLA/SE induced antibodies as compared to Alum and SE. TLR synergy was not observed when soluble R848 was mixed with GLA/SE. Antibody response of 3M051 formulations in Balb/c was similar to GLA/SE, except for the higher IgG2:IgG1 ratio and a trend towards higher T cell responses in 3M051 containing groups. However, no synergistic enhancement of antibody and T cell response was evident when 3M051 conjugate was mixed with GLA/SE. In C57Bl/6 mice, CS/D adjuvanted with 3M051/SE or GLA/SE induced higher CSP repeat specific titers compared to SE. While, 3M051 induced antibodies had high IgG2c:IgG1 ratio, GLA/SE promoted high levels of both IgG1 and IgG2c. GLA/SE also induced more potent T-cell responses compared to SE in two independent C57/BL6 vaccination studies, suggesting a balanced and productive T(H1/T(H2 response. GLA and 3M-051 similarly enhanced the protective efficacy of CS/D against challenge with a transgenic P. berghei parasite and most importantly, high levels of cytophilic IgG2 antibodies were associated with protection in this model. Our data indicated that the cGMP-grade, soluble CS/D antigen combined with the TLR4-containing adjuvant GLA/SE warrants

  16. IgG2 Antibodies against a Clinical Grade Plasmodium falciparum CSP Vaccine Antigen Associate with Protection against Transgenic Sporozoite Challenge in Mice

    Science.gov (United States)

    Schwenk, Robert; Nikki, Jennifer; Rein, Lisa; Spaccapelo, Roberta; Crisanti, Andrea; Wightman, Paul D.; Ockenhouse, Christian F.; Dutta, Sheetij

    2014-01-01

    The availability of a highly purified and well characterized circumsporozoite protein (CSP) is essential to improve upon the partial success of recombinant CSP-based malaria vaccine candidates. Soluble, near full-length, Plasmodium falciparum CSP vaccine antigen (CS/D) was produced in E. coli under bio-production conditions that comply with current Good Manufacturing Practices (cGMP). A mouse immunogenicity study was conducted using a stable oil-in-water emulsion (SE) of CS/D in combination with the Toll-Like Receptor 4 (TLR4) agonist Glucopyranosyl Lipid A (GLA/SE), or one of two TLR7/8 agonists: R848 (un-conjugated) or 3M-051 (covalently conjugated). Compared to Alum and SE, GLA/SE induced higher CS/D specific antibody response in Balb/c mice. Subclass analysis showed higher IgG2:IgG1 ratio of GLA/SE induced antibodies as compared to Alum and SE. TLR synergy was not observed when soluble R848 was mixed with GLA/SE. Antibody response of 3M051 formulations in Balb/c was similar to GLA/SE, except for the higher IgG2:IgG1 ratio and a trend towards higher T cell responses in 3M051 containing groups. However, no synergistic enhancement of antibody and T cell response was evident when 3M051 conjugate was mixed with GLA/SE. In C57Bl/6 mice, CS/D adjuvanted with 3M051/SE or GLA/SE induced higher CSP repeat specific titers compared to SE. While, 3M051 induced antibodies had high IgG2c:IgG1 ratio, GLA/SE promoted high levels of both IgG1 and IgG2c. GLA/SE also induced more potent T-cell responses compared to SE in two independent C57/BL6 vaccination studies, suggesting a balanced and productive TH1/TH2 response. GLA and 3M-051 similarly enhanced the protective efficacy of CS/D against challenge with a transgenic P. berghei parasite and most importantly, high levels of cytophilic IgG2 antibodies were associated with protection in this model. Our data indicated that the cGMP-grade, soluble CS/D antigen combined with the TLR4-containing adjuvant GLA/SE warrants further

  17. Immunogenic profiling in mice of a HIV/AIDS vaccine candidate (MVA-B expressing four HIV-1 antigens and potentiation by specific gene deletions.

    Directory of Open Access Journals (Sweden)

    Juan García-Arriaza

    Full Text Available BACKGROUND: The immune parameters of HIV/AIDS vaccine candidates that might be relevant in protection against HIV-1 infection are still undefined. The highly attenuated poxvirus strain MVA is one of the most promising vectors to be use as HIV-1 vaccine. We have previously described a recombinant MVA expressing HIV-1 Env, Gag, Pol and Nef antigens from clade B (referred as MVA-B, that induced HIV-1-specific immune responses in different animal models and gene signatures in human dendritic cells (DCs with immunoregulatory function. METHODOLOGY/PRINCIPAL FINDINGS: In an effort to characterize in more detail the immunogenic profile of MVA-B and to improve its immunogenicity we have generated a new vector lacking two genes (A41L and B16R, known to counteract host immune responses by blocking the action of CC-chemokines and of interleukin 1beta, respectively (referred as MVA-B DeltaA41L/DeltaB16R. A DNA prime/MVA boost immunization protocol was used to compare the adaptive and memory HIV-1 specific immune responses induced in mice by the parental MVA-B and by the double deletion mutant MVA-B DeltaA41L/DeltaB16R. Flow cytometry analysis revealed that both vectors triggered HIV-1-specific CD4(+ and CD8(+ T cells, with the CD8(+ T-cell compartment responsible for >91.9% of the total HIV-1 responses in both immunization groups. However, MVA-B DeltaA41L/DeltaB16R enhanced the magnitude and polyfunctionality of the HIV-1-specific CD4(+ and CD8(+ T-cell immune responses. HIV-1-specific CD4(+ T-cell responses were polyfunctional and preferentially Env-specific in both immunization groups. Significantly, while MVA-B induced preferentially Env-specific CD8(+ T-cell responses, MVA-B DeltaA41L/DeltaB16R induced more GPN-specific CD8(+ T-cell responses, with an enhanced polyfunctional pattern. Both vectors were capable of producing similar levels of antibodies against Env. CONCLUSIONS/SIGNIFICANCE: These findings revealed that MVA-B and MVA-B DeltaA41L/DeltaB16R

  18. Differentiation of foot-and-mouth disease virus infected animals from vaccinated animals using a blocking ELISA based on baculovirus expressed FMDV 3ABC antigen and a 3ABC monoclonal antibody

    DEFF Research Database (Denmark)

    Sørensen, K.J.; de Stricker, K.; Dyrting, K.C.;

    2005-01-01

    A blocking ELISA that differentiated foot-and-mouth disease virus (FMDV) infected animals from vaccinated animals was developed which uses baculovirus expressed FMDV 3ABC non-structural protein as antigen and monoclonal antibody against FMDV 3ABC non-structural protein as capture and detector...... infected with all seven serotypes of FMDV. The test detected antibodies from days 7 or 9 following experimental infection of non-vaccinated cattle and sheep, and in cattle strong positive reactions persisted for up to 395 days after infection. In vaccinated cattle that became carriers after challenge...... with homologous FMDV, positive reactions were obtained in all but one case. In some of these cattle the antibody response was detected late in comparison to the non-vaccinated infected cattle. The test gave results that compared favourably with two commercial ELISA's when used to test sera from cattle, pigs...

  19. Comparative analysis of the immunologic response induced by the Sterne 34F2 live spore Bacillus anthracis vaccine in a ruminant model.

    Science.gov (United States)

    Ndumnego, Okechukwu C; Köhler, Susanne M; Crafford, Jannie; van Heerden, Henriette; Beyer, Wolfgang

    2016-10-01

    The Sterne 34F2 live spore vaccine (SLSV) developed in 1937 is the most widely used veterinary vaccine against anthrax. However, literature on the immunogenicity of this vaccine in a target ruminant host is scarce. In this study, we evaluated the humoral response to the Bacillus anthracis protective antigen (rPA), a recombinant bacillus collagen-like protein of anthracis (rBclA), formaldehyde inactivated spores (FIS) prepared from strain 34F2 and a vegetative antigen formulation prepared from a capsule and toxin deficient strain (CDC 1014) in Boer goats. The toxin neutralizing ability of induced antibodies was evaluated using an in vitro toxin neutralization assay. The protection afforded by the vaccine was also assessed in vaccinates. Anti-rPA, anti-FIS and lethal toxin neutralizing titres were superior after booster vaccinations, compared to single vaccinations. Qualitative analysis of humoral responses to rPA, rBclA and FIS antigens revealed a preponderance of anti-FIS IgG titres following either single or double vaccinations with the SLSV. Antibodies against FIS and rPA both increased by 350 and 300-fold following revaccinations respectively. There was no response to rBclA following vaccinations with the SLSV. Toxin neutralizing titres increased by 80-fold after single vaccination and 700-fold following a double vaccination. Lethal challenge studies in naïve goats indicated a minimum infective dose of 36 B. anthracis spores. Single and double vaccination with the SLSV protected 4/5 and 3/3 of goats challenged with>800 spores respectively. An early booster vaccination following the first immunization is suggested in order to achieve a robust immunity. Results from this study indicate that this crucial second vaccination can be administered as early as 3 months after the initial vaccination. PMID:27496738

  20. B5 deficient vaccinia virus as a vaccine vector for the expression of a foreign antigen in vaccinia immune animals

    OpenAIRE

    Viner, Kendra M.; Girgis, Natasha; Kwak, Heesun; Isaacs, Stuart N.

    2006-01-01

    Recombinant vaccinia viruses have shown promise as vaccine vectors. However, their effectiveness is markedly reduced by pre-existing anti-vaccinia immunity. The possibility of new vaccinia immunizations in the event of a bioterror-related smallpox release poses an additional negative impact on the utility of vaccinia-based vectors. Thus, we aimed to design a vaccinia vector that would enhance the immune response to an expressed foreign protein in a pre-immune animal model. To do this, we made...

  1. An alternative and effective HIV vaccination approach based on inhibition of antigen presentation attenuators in dendritic cells.

    OpenAIRE

    Xiao-Tong Song; Kevin Evel-Kabler; Lisa Rollins; Melissa Aldrich; Feng Gao; Xue F Huang; Si-Yi Chen

    2006-01-01

    BACKGROUND: Current efforts to develop HIV vaccines that seek to stimulate immune responses have been disappointing, underscoring the inability of natural immune responses to control HIV-1 infection. Here we tested an alternative strategy to induce anti-HIV immune responses by inhibiting a host's natural immune inhibitor. METHODS AND FINDINGS: We used small interfering RNA (siRNA) to inhibit suppressor of cytokine signaling (SOCS) 1, a key negative regulator of the JAK/STAT pathway, and inves...

  2. Comparison of Vaccine-Induced Effector CD8 T Cell Responses Directed against Self- and Non-Self-Tumor Antigens

    DEFF Research Database (Denmark)

    Pedersen, Sara R; Sørensen, Maria R; Buus, Søren;

    2013-01-01

    construct expressing a foreign (viral) TA induced efficient tumor control. Analyzing the self-TA-specific CD8 T cells, we observed that these could be activated to produce IFN-γ and TNF-α. In addition, surface expression of phenotypic markers and inhibitory receptors, as well as in vivo cytotoxicity and......It is generally accepted that CD8 T cells play a major role in tumor control, yet vaccination aimed at eliciting potent CD8 T cell responses are rarely efficient in clinical trials. To try and understand why this is so, we have generated potent adenoviral vectors encoding the endogenous tumor Ags....... Prophylactic vaccination with adenoviral vectors expressing either TRP-2 (Ad-Ii-TRP-2) or GP100 (Ad-Ii-GP100) had little or no effect on the growth of s.c. B16 melanomas, and only Ad-Ii-TRP-2 was able to induce a marginal reduction of B16 lung metastasis. In contrast, vaccination with a similar vector...

  3. A new Leishmania-specific hypothetical protein, LiHyT, used as a vaccine antigen against visceral leishmaniasis.

    Science.gov (United States)

    Martins, Vívian Tamietti; Lage, Daniela Pagliara; Duarte, Mariana Costa; Costa, Lourena Emanuele; Garde, Esther; Rodrigues, Marcella Rezende; Chávez-Fumagalli, Miguel Angel; Menezes-Souza, Daniel; Roatt, Bruno Mendes; Tavares, Carlos Alberto Pereira; Soto, Manuel; Coelho, Eduardo Antonio Ferraz

    2016-02-01

    The present study aimed to evaluate a new Leishmania-specific hypothetical protein, LiHyT, as a vaccine candidate against VL. The immunogenicity of the recombinant protein (rLiHyT) plus saponin was evaluated in BALB/c mice. In the results, it is shown that rLiHyT plus saponin vaccinated mice produced high levels of IFN-γ, IL-12, and GM-CSF after in vitro stimulation of spleen cells using both rLiHyT and Leishmania infantum SLA. The protective efficacy was evaluated after subcutaneous challenge with stationary promastigotes of L. infantum. Immunized and infected mice, when compared to the controls, showed significant reductions in the number of parasites in the liver, spleen, bone marrow, and in the paws' draining lymph nodes. Protection was associated with an IL-12-dependent production of IFN-γ, mainly by CD4(+) T cells, with a minor contribution of CD8(+) T cells. In these mice, a decrease in the parasite-mediated IL-4 and IL-10 responses, as well as a predominance of LiHyT- and parasite-specific IgG2a isotype antibodies, were also observed. The present study showed that a new Leishmania-specific protein, when combined with a Th1-type adjuvant, presents potential to be used as a vaccine against VL. PMID:26593442

  4. Different Vaccine Vectors Delivering the Same Antigen Elicit CD8plus T Cell Responses with Distinct Clonotype and Epitope Specificity

    Energy Technology Data Exchange (ETDEWEB)

    M Honda; R Wang; W Kong; M Kanekiyo; Q Akahata; L Xu; K Matsuo; K Natarajan; H Robinson; et al.

    2011-12-31

    Prime-boost immunization with gene-based vectors has been developed to generate more effective vaccines for AIDS, malaria, and tuberculosis. Although these vectors elicit potent T cell responses, the mechanisms by which they stimulate immunity are not well understood. In this study, we show that immunization by a single gene product, HIV-1 envelope, with alternative vector combinations elicits CD8{sup +} cells with different fine specificities and kinetics of mobilization. Vaccine-induced CD8{sup +} T cells recognized overlapping third V region loop peptides. Unexpectedly, two anchor variants bound H-2D{sup d} better than the native sequences, and clones with distinct specificities were elicited by alternative vectors. X-ray crystallography revealed major differences in solvent exposure of MHC-bound peptide epitopes, suggesting that processed HIV-1 envelope gave rise to MHC-I/peptide conformations recognized by distinct CD8{sup +} T cell populations. These findings suggest that different gene-based vectors generate peptides with alternative conformations within MHC-I that elicit distinct T cell responses after vaccination.

  5. Different Vaccine Vectors Delivering the Same Antigen Elicit CD8+ T Cell Responses with Distinct Clonotype and Epitope Specificity

    Energy Technology Data Exchange (ETDEWEB)

    Honda, M.; Robinson, H.; Wang, R.; Kong, W.-P.; Kanekiyo, M.; Akahata, W.; Xu, L.; Matsuo, K.; Natarajan, K.; Asher, T. E.; Price, D. A.; Douek, D. C.; Margulies, D. H.; Nabel, G. J.

    2009-08-15

    Prime-boost immunization with gene-based vectors has been developed to generate more effective vaccines for AIDS, malaria, and tuberculosis. Although these vectors elicit potent T cell responses, the mechanisms by which they stimulate immunity are not well understood. In this study, we show that immunization by a single gene product, HIV-1 envelope, with alternative vector combinations elicits CD8{sup +} cells with different fine specificities and kinetics of mobilization. Vaccine-induced CD8{sup +} T cells recognized overlapping third V region loop peptides. Unexpectedly, two anchor variants bound H-2D{sup d} better than the native sequences, and clones with distinct specificities were elicited by alternative vectors. X-ray crystallography revealed major differences in solvent exposure of MHC-bound peptide epitopes, suggesting that processed HIV-1 envelope gave rise to MHC-I/peptide conformations recognized by distinct CD8{sup +} T cell populations. These findings suggest that different gene-based vectors generate peptides with alternative conformations within MHC-I that elicit distinct T cell responses after vaccination.

  6. Molecular characterization of thyroid hormone receptor beta from Schistosoma japonicum and assessment of its potential as a vaccine candidate antigen against schistosomiasis in BALB/c mice

    Directory of Open Access Journals (Sweden)

    Qiu Chunhui

    2012-08-01

    Full Text Available Abstract Background Thyroid hormones (TH modulate growth, development and differentiation and metabolic processes by interacting with thyroid hormone receptors (THRs. The purpose of this study was to identify a novel thyroid hormone receptor beta encoding gene of Schistosoma japonicum (SjTHRβ and to investigate its potential as a vaccine candidate antigen against schistosomiasis in BALB/c mice. Methods The full-length cDNA sequence of SjTHRβ, its gene organization, and its transcript levels were characterized, and the phylogenetic relationship between THR, RAR and RXR from other organisms were analysis, the ability of this protein binding to a conserved DNA core motif, and its potential as a vaccine candidate antigen against schistosomiasis in BALB/c mice were evaluated. Results The SjTHRβ cDNA was cloned, verified by 5’ and 3’ Rapid Amplification of cDNA Ends and shown to be polyadenylated at the 3’end, suggesting the transcript is full-length. SjTHRβ is homologous to THRs from other species and has a predicted conservative DNA binding domain and ligand binding domain that normally characterizes these receptors. A comparative quantitative PCR analysis showed that SjTHRβ was the highest expressed in 21d worms and the lowest in 7 d and 13 d schistosomula. The cDNA corresponding to DNA binding domain (SjTHRβ-DBD and ligand binding domain (SjTHRβ-LBD were cloned and subsequently expressed in E coli. The expressed proteins were used to immunize mice and generate specific serum against recombinant SjTHRβ (rSjTHRβ. Western blotting revealed that anti-rSjTHRβ-LBD serum recognized two protein bands in extracts from 21 d worm with molecular sizes of approximately 95 kDa and 72 kDa. Electrophoretic mobility shift assay (EMSA analysis showed that rSjTHRβ-DBD could bind to a conserved DNA core motif. Immunization of BALB/c mice with rSjTHRβ-LBD could induce partial protective efficacy(27.52% worm reduction and 29.50% liver eggs

  7. Invitro immune responses in children following BCG vaccination

    Directory of Open Access Journals (Sweden)

    Vijayalakshmi V

    2006-01-01

    Full Text Available Introduction: There is still no consensus on the efficacy of BCG vaccine in the prevention of tuberculosis. This study therefore addressed the question of the magnitude of immunity afforded by BCG, by studying the effector mechanisms of protection in children. The main objectives were to assess the degree of immunity conferred by BCG vaccine in children and to identify the most immunogenic antigen(s of BCG by conducting in-vitro studies. Materials and methods: Children in the age-group of 1 to 10 years, were categorized: (A normal, and vaccinated with BCG during the first year, n=45, (B normal, without scar and with no evident history of vaccination, n=31: and (C children admitted in the hospital with a confirmed diagnosis of tuberculosis, n=31. Fractions of BCG were obtained by lysis, sonication, separation by gel chromatography, HPLC and confirmed by SDS-PAGE. In lymphoproliferative assays PBMC were cultured and stimulated with either Concanavalin-A or Tuberculin or the fractions of BCG. Stimulation indices (SI in lymphoproliferation, CD4/CD8 cells, levels of Interferon-γ (IFN- γ in the culture supernatants were measured by ELISA. Results: The vaccinated children displayed significantly high (P< 0.05 mean values of SI in LTT, CD4/CD8 cell ratio against the unfractionated, 67kDa fraction and BCG-CF Ags. While 100% of the vaccinated children had positive lymphoproliferation indices to BCG-CF, only 8.3% of the unvaccinated children were positive. Conclusion: Some of the components of BCG induced a strong Thl cell response in children. These immunogenic antigens were present in the whole cell lysate. The use of BCG vaccine for tuberculosis is worthwhile till a new vaccine is developed.

  8. Concerted activity of IgG1 antibodies and IL-4/IL-25-dependent effector cells trap helminth larvae in the tissues following vaccination with defined secreted antigens, providing sterile immunity to challenge infection.

    Directory of Open Access Journals (Sweden)

    James P Hewitson

    2015-03-01

    Full Text Available Over 25% of the world's population are infected with helminth parasites, the majority of which colonise the gastrointestinal tract. However, no vaccine is yet available for human use, and mechanisms of protective immunity remain unclear. In the mouse model of Heligmosomoides polygyrus infection, vaccination with excretory-secretory (HES antigens from adult parasites elicits sterilising immunity. Notably, three purified HES antigens (VAL-1, -2 and -3 are sufficient for effective vaccination. Protection is fully dependent upon specific IgG1 antibodies, but passive transfer confers only partial immunity to infection, indicating that cellular components are also required. Moreover, immune mice show greater cellular infiltration associated with trapping of larvae in the gut wall prior to their maturation. Intra-vital imaging of infected intestinal tissue revealed a four-fold increase in extravasation by LysM+GFP+ myeloid cells in vaccinated mice, and the massing of these cells around immature larvae. Mice deficient in FcRγ chain or C3 complement component remain fully immune, suggesting that in the presence of antibodies that directly neutralise parasite molecules, the myeloid compartment may attack larvae more quickly and effectively. Immunity to challenge infection was compromised in IL-4Rα- and IL-25-deficient mice, despite levels of specific antibody comparable to immune wild-type controls, while deficiencies in basophils, eosinophils or mast cells or CCR2-dependent inflammatory monocytes did not diminish immunity. Finally, we identify a suite of previously uncharacterised heat-labile vaccine antigens with homologs in human and veterinary parasites that together promote full immunity. Taken together, these data indicate that vaccine-induced immunity to intestinal helminths involves IgG1 antibodies directed against secreted proteins acting in concert with IL-25-dependent Type 2 myeloid effector populations.

  9. Removing N-Terminal Sequences in Pre-S1 Domain Enhanced Antibody and B-Cell Responses by an HBV Large Surface Antigen DNA Vaccine

    OpenAIRE

    Guohong Ge; Shixia Wang; Yaping Han; Chunhua Zhang; Shan Lu; Zuhu Huang

    2012-01-01

    Although the use of recombinant hepatitis B virus surface (HBsAg) protein vaccine has successfully reduced global hepatitis B infection, there are still a number of vaccine recipients who do not develop detectable antibody responses. Various novel vaccination approaches, including DNA vaccines, have been used to further improve the coverage of vaccine protection. Our previous studies demonstrated that HBsAg-based DNA vaccines could induce both humoral and CMI responses in experimental animal ...

  10. Constitutive expression of the Vi polysaccharide capsular antigen in attenuated Salmonella enterica serovar typhi oral vaccine strain CVD 909.

    Science.gov (United States)

    Wang, J Y; Noriega, F R; Galen, J E; Barry, E; Levine, M M

    2000-08-01

    Live oral Ty21a and parenteral Vi polysaccharide vaccines provide significant protection against typhoid fever, albeit by distinct immune mechanisms. Vi stimulates serum immunoglobulin G Vi antibodies, whereas Ty21a, which does not express Vi, elicits humoral and cell-mediated immune responses other than Vi antibodies. Protection may be enhanced if serum Vi antibody as well as cell-mediated and humoral responses can be stimulated. Disappointingly, several new attenuated Salmonella enterica serovar Typhi oral vaccines (e.g., CVD 908-htrA and Ty800) that elicit serum O and H antibody and cell-mediated responses following a single dose do not stimulate serum Vi antibody. Vi expression is regulated in response to environmental signals such as osmolarity by controlling the transcription of tviA in the viaB locus. To investigate if Vi antibodies can be stimulated if Vi expression is rendered constitutive, we replaced P(tviA) in serovar Typhi vaccine CVD 908-htrA with the constitutive promoter P(tac), resulting in CVD 909. CVD 909 expresses Vi even under high-osmolarity conditions and is less invasive for Henle 407 cells. In mice immunized with a single intranasal dose, CVD 909 was more immunogenic than CVD 908-htrA in eliciting serum Vi antibodies (geometric mean titer of 160 versus 49, P = 0.0007), whereas O antibody responses were virtually identical (geometric mean titer of 87 versus 80). In mice challenged intraperitoneally with wild-type serovar Typhi 4 weeks after a single intranasal immunization, the mortality of those immunized with CVD 909 (3 of 8) was significantly lower than that of control mice (10 of 10, P = 0.043) or mice given CVD 908-htrA (9 of 10, P = 0.0065). PMID:10899868

  11. Vaccination of pigs with Toxoplasma gondii antigens incorporated in immunostimulating complexes (iscoms) Vacinação de suínos com antígenos de Toxoplasma gondii incorporados a complexos imunoestimulantes (iscoms)

    OpenAIRE

    R.L. Freire; I.T. Navarro; A.P.F.R.L. Bracarense; Gennari, S. M.

    2003-01-01

    Immunity to Toxoplasma gondii was studied in pigs, after vaccination with T. gondii antigens incorporated into immunostimulating complexes. Nine pigs (group 1 - G1) were inoculated subcutaneously with T. gondii iscoms (LIV-5 sample) and three doses were given at 21 and 13 day-intervals. The results were compared in other three groups of nine pigs each: animals in group 2 (G2) were immunized with the LIV-5 antigens without Quil A, animals in group 3 (G3) were inoculated with tachyzoites of RH ...

  12. Protective Effect of Vaccination with a Combination of Recombinant Surface Antigen 1 and Interleukin-12 against Toxoplasmosis in Mice

    OpenAIRE

    Letscher-Bru, Valerie; Villard, Odile; Risse, Bernhard; Zauke, Michael; Klein, Jean-Paul; Kien, Truong T.

    1998-01-01

    We studied the immune response induced in mice by recombinant Toxoplasma gondii surface antigen 1 (rSAG1) protein, alone or combined with interleukin-12 (IL-12) as an adjuvant, and the protective effect against toxoplasmosis. Immunization with rSAG1 alone induced a specific humoral type 2 immunity and did not protect the animals from infection. In contrast, immunization with rSAG1 plus IL-12 redirected humoral and cellular immunity toward a type 1 pattern and reduced the brain parasite load b...

  13. Transcriptional profiling of serogroup B Neisseria meningitidis growing in human blood: an approach to vaccine antigen discovery.

    Science.gov (United States)

    Hedman, Åsa K; Hedman, Asa K; Li, Ming-Shi; Langford, Paul R; Kroll, J Simon

    2012-01-01

    Neisseria meningitidis is a nasopharyngeal commensal of humans which occasionally invades the blood to cause septicaemia. The transcriptome of N. meningitidis strain MC58 grown in human blood for up to 4 hours was determined and around 10% of the genome was found to be differentially regulated. The nuo, pet and atp operons, involved in energy metabolism, were up-regulated, while many house-keeping genes were down-regulated. Genes encoding protein chaperones and proteases, involved in the stress response; complement resistant genes encoding enzymes for LOS sialylation and biosynthesis; and fHbp (NMB1870) and nspA (NMB0663), encoding vaccine candidates, were all up-regulated. Genes for glutamate uptake and metabolism, and biosynthesis of purine and pyrimidine were also up-regulated. Blood grown meningococci are under stress and undergo a metabolic adaptation and energy conservation strategy. The localisation of four putative outer membrane proteins encoded by genes found to be up-regulated in blood was assessed by FACS using polyclonal mouse antisera, and one (NMB0390) showed evidence of surface expression, supporting its vaccine candidacy. PMID:22745818

  14. Amino-functionalized poly(L-lactide lamellar single crystals as a valuable substrate for delivery of HPV16-E7 tumor antigen in vaccine development

    Directory of Open Access Journals (Sweden)

    Di Bonito P

    2015-05-01

    Full Text Available Paola Di Bonito,1 Linda Petrone,1 Gabriele Casini,2 Iolanda Francolini,2 Maria Grazia Ammendolia,3 Luisa Accardi,1 Antonella Piozzi,2 Lucio D’Ilario,2 Andrea Martinelli2 1Department of Infectious, Parasitic and Immune-mediated Diseases, Italian National Institute of Health, 2Department of Chemistry, Sapienza University of Rome, Rome, Italy; 3Department of Technology and Health, Italian National Institute of Health, Rome, Italy Background: Poly(L-lactide (PLLA is a biodegradable polymer currently used in many biomedical applications, including the production of resorbable surgical devices, porous scaffolds for tissue engineering, nanoparticles and microparticles for the controlled release of drugs or antigens. The surfaces of lamellar PLLA single crystals (PLLAsc were provided with amino groups by reaction with a multifunctional amine and used to adsorb an Escherichia coli-produced human papillomavirus (HPV16-E7 protein to evaluate its possible use in antigen delivery for vaccine development.Methods: PLLA single crystals were made to react with tetraethylenepentamine to obtain amino-functionalized PLLA single crystals (APLLAsc. Pristine and amino-functionalized PLLAsc showed a two-dimensional microsized and one-dimensional nanosized lamellar morphology, with a lateral dimension of about 15–20 µm, a thickness of about 12 nm, and a surface specific area of about 130 m2/g. Both particles were characterized and loaded with HPV16-E7 before being administered to C57BL/6 mice for immunogenicity studies. The E7-specific humoral-mediated and cell-mediated immune response as well as tumor protective immunity were analyzed in mice challenged with TC-1 cancer cells.Results: Pristine and amino-functionalized PLLAsc adsorbed similar amounts of E7 protein, but in protein-release experiments E7-PLLAsc released a higher amount of protein than E7-APLLAsc. When the complexes were dried for observation by scanning electron microscopy, both samples showed a

  15. Tumor vaccines

    International Nuclear Information System (INIS)

    Tumor vaccines have several potential advantages over standard anticancer regiments. They represent highly specific anticancer therapy. Inducing tumor-specific memory T-lymphocytes, they have potential for long-lived antitumor effects. However, clinical trials, in which cancer patients were vaccinated with tumor vaccines, have been so far mainly disappointing. There are many reasons for the inefficiency of tumor vaccines. Most cancer antigens are normal self-molecules to which immune tolerance exists. That is why the population of tumor-specific lymphocytes is represented by a small number of low-affinity T-lymphocytes that induce weak antitumor immune response. Simultaneously, tumors evolve many mechanisms to actively evade immune system, what makes them poorly immunogenic or even tolerogenic. Novel immunotherapeutic strategies are directed toward breaking immune tolerance to tumor antigens, enhancing immunogenicity of tumor vaccines and overcoming mechanisms of tumor escape. There are several approaches, unfortunately, all of them still far away from an ideal tumor vaccine that would reject a tumor. Difficulties in the activation of antitumor immune response by tumor vaccines have led to the development of alternative immunotherapeutic strategies that directly focus on effector mechanisms of immune system (adoptive tumor- specific T-lymphocyte transfer and tumor specific monoclonal antibodies). (author)

  16. Typhoid vaccines.

    Science.gov (United States)

    Aggarwal, A; Dutta, A K

    2001-08-01

    Typhoid fever continues to be a major public health problem in developing countries with about 33 million cases per year. Protective efficacy of traditional acetone/phenol killed vaccines is similar to newer typhoid vaccines (Ty21A and Vi antigen vaccine) but side effects of these newer vaccines are considerably less. Though the mortality is low, typhoid fever causes considerable morbidity and loss of working days. Problems during treatment are increasing due to emergence and spread of multidrug resistant S. typhi. Hence to decrease the incidence of typhoid fever in addition to ensuring safe water supply and excreta disposal a typhoid vaccine needs to be introduced in the National Immunization Schedule. PMID:11563251

  17. Immunological Cross-Reactivity between Malaria Vaccine Target Antigen P48/45 in Plasmodium vivax and P. falciparum and Cross–Boosting of Immune Responses

    Science.gov (United States)

    Cao, Yi; Bansal, Geetha P.; Merino, Kristen; Kumar, Nirbhay

    2016-01-01

    In general, malaria immunity has been suggested to be species specific with very little, if any, known cross-reactivity between Plasmodium vivax and P. falciparum, both of which are responsible for >90% of human malaria, and co-endemic in many countries. It is therefore believed that species-specific immunity may be needed to target different species of Plasmodium. Pfs48/45 and Pvs48/45 are well established targets in the sexual stages of the malaria parasites, and are being pursued for the development of transmission blocking vaccines. Comparison of their sequences reveals 61% and 55% identity at the DNA and protein level, respectively raising the possibility that these two target antigens might share cross-reacting epitopes. Having succeeded in expressing recombinant Pfs48/45 and Pvs48/45 proteins, we hypothesized that these proteins will not only exhibit immunological cross–reactivity but also cross-boost immune responses. Mice were immunized with purified recombinant proteins using CFA, Montanide ISA-51 and alum as adjuvants, and the sera were analyzed by ELISA, Western blotting and indirect fixed and live IFA to address the hypothesis. Our studies revealed that Pvs48/45-immune sera showed strong cross-reactivity to full length Pfs48/45 protein, and the majority of this cross reactivity was in the amino-terminal and carboxyl-terminal sub-fragments of Pfs48/45. In cross-boosting experiments Pfs48/45 and Pvs48/45 antigens were able to cross-boost each other in mouse immunization studies. Additionally we also noticed an effect of adjuvants in the overall magnitude of observed cross-reactivity. These studies may have significant implications for immunity targeting transmission of both the species of malaria parasites. PMID:27438603

  18. Differentiation of foot-and-mouth disease virus-infected from vaccinated pigs by enzyme-linked immunosorbent assay using nonstructural protein 3AB as the antigen and application to an eradication program

    DEFF Research Database (Denmark)

    Chung, Wen Bin; Sørensen, Karl Johan; Liao, Pei Chih;

    2002-01-01

    Baculovirus-expressed foot-and-mouth disease virus (FMDV) nonstructural protein 3AB was used as the antigen in an enzyme-linked immunosorbent assay. This assay allowed the differentiation of vaccinated from infected pigs. Serial studies were performed using sera collected from pigs in the field...... in Taiwan showed that the positive reactors steadily decreased over time in both finishers and sows, indicating that the pig population risk of infection by FMDV has decreased....

  19. Humans and Ferrets with Prior H1N1 Influenza Virus Infections Do Not Exhibit Evidence of Original Antigenic Sin after Infection or Vaccination with the 2009 Pandemic H1N1 Influenza Virus

    OpenAIRE

    O'Donnell, Christopher D.; Wright, Amber; Vogel, Leatrice; Boonnak, Kobporn; Treanor, John J.; Subbarao, Kanta

    2014-01-01

    The hypothesis of original antigenic sin (OAS) states that the imprint established by an individual's first influenza virus infection governs the antibody response thereafter. Subsequent influenza virus infection results in an antibody response against the original infecting virus and an impaired immune response against the newer influenza virus. The purpose of our study was to seek evidence of OAS after infection or vaccination with the 2009 pandemic H1N1 (2009 pH1N1) virus in ferrets and hu...

  20. Co-Administration of Molecular Adjuvants Expressing NF-Kappa B Subunit p65/RelA or Type-1 Transactivator T-bet Enhance Antigen Specific DNA Vaccine-Induced Immunity

    Directory of Open Access Journals (Sweden)

    Devon J. Shedlock

    2014-03-01

    Full Text Available DNA vaccine-induced immunity can be enhanced by the co-delivery of synthetic gene-encoding molecular adjuvants. Many of these adjuvants have included cytokines, chemokines or co-stimulatory molecules that have been demonstrated to enhance vaccine-induced immunity by increasing the magnitude or type of immune responses and/or protective efficacy. In this way, through the use of adjuvants, immune responses can be highly customizable and functionally tailored for optimal efficacy against pathogen specific (i.e., infectious agent or non-pathogen (i.e., cancer antigens. In the novel study presented here, we examined the use of cellular transcription factors as molecular adjuvants. Specifically the co-delivery of (a RelA, a subunit of the NF-κB transcription complex or (b T-bet, a Th1-specific T box transcription factor, along with a prototypical DNA vaccine expressing HIV-1 proteins was evaluated. As well, all of the vaccines and adjuvants were administered to mice using in vivo electroporation (EP, a technology demonstrated to dramatically increase plasmid DNA transfection and subsequent transgene expression with concomitant enhancement of vaccine induced immune responses. As such, this study demonstrated that co-delivery of either adjuvant resulted in enhanced T and B cell responses, specifically characterized by increased T cell numbers, IFN-γ production, as well as enhanced antibody responses. This study demonstrates the use of cellular transcription factors as adjuvants for enhancing DNA vaccine-induced immunity.

  1. RECOMBINANT INFLUENZA VACCINES

    OpenAIRE

    Sedova, E.; Shcherbinin, D.; Migunov, A.; Smirnov, Iu; Logunov, D.; Shmarov, M.; Tsybalova, L.; Naroditskiĭ, B.; O. Kiselev; Gintsburg, A.

    2012-01-01

    This review covers the problems encountered in the construction and production of new recombinant influenza vaccines. New approaches to the development of influenza vaccines are investigated; they include reverse genetics methods, production of virus-like particles, and DNA- and viral vector-based vaccines. Such approaches as the delivery of foreign genes by DNA- and viral vector-based vaccines can preserve the native structure of antigens. Adenoviral vectors are a promising gene-delivery pla...

  2. Thermoregulation of Meningococcal fHbp, an Important Virulence Factor and Vaccine Antigen, Is Mediated by Anti-ribosomal Binding Site Sequences in the Open Reading Frame.

    Science.gov (United States)

    Loh, Edmund; Lavender, Hayley; Tan, Felicia; Tracy, Alexander; Tang, Christoph M

    2016-08-01

    During colonisation of the upper respiratory tract, bacteria are exposed to gradients of temperatures. Neisseria meningitidis is often present in the nasopharynx of healthy individuals, yet can occasionally cause severe disseminated disease. The meningococcus can evade the human complement system using a range of strategies that include recruitment of the negative complement regulator, factor H (CFH) via factor H binding protein (fHbp). We have shown previously that fHbp levels are influenced by the ambient temperature, with more fHbp produced at higher temperatures (i.e. at 37°C compared with 30°C). Here we further characterise the mechanisms underlying thermoregulation of fHbp, which occurs gradually over a physiologically relevant range of temperatures. We show that fHbp thermoregulation is not dependent on the promoters governing transcription of the bi- or mono-cistronic fHbp mRNA, or on meningococcal specific transcription factors. Instead, fHbp thermoregulation requires sequences located in the translated region of the mono-cistronic fHbp mRNA. Site-directed mutagenesis demonstrated that two anti-ribosomal binding sequences within the coding region of the fHbp transcript are involved in fHbp thermoregulation. Our results shed further light on mechanisms underlying the control of the production of this important virulence factor and vaccine antigen. PMID:27560142

  3. Thermoregulation of Meningococcal fHbp, an Important Virulence Factor and Vaccine Antigen, Is Mediated by Anti-ribosomal Binding Site Sequences in the Open Reading Frame

    Science.gov (United States)

    Loh, Edmund; Lavender, Hayley; Tan, Felicia; Tracy, Alexander; Tang, Christoph M.

    2016-01-01

    During colonisation of the upper respiratory tract, bacteria are exposed to gradients of temperatures. Neisseria meningitidis is often present in the nasopharynx of healthy individuals, yet can occasionally cause severe disseminated disease. The meningococcus can evade the human complement system using a range of strategies that include recruitment of the negative complement regulator, factor H (CFH) via factor H binding protein (fHbp). We have shown previously that fHbp levels are influenced by the ambient temperature, with more fHbp produced at higher temperatures (i.e. at 37°C compared with 30°C). Here we further characterise the mechanisms underlying thermoregulation of fHbp, which occurs gradually over a physiologically relevant range of temperatures. We show that fHbp thermoregulation is not dependent on the promoters governing transcription of the bi- or mono-cistronic fHbp mRNA, or on meningococcal specific transcription factors. Instead, fHbp thermoregulation requires sequences located in the translated region of the mono-cistronic fHbp mRNA. Site-directed mutagenesis demonstrated that two anti-ribosomal binding sequences within the coding region of the fHbp transcript are involved in fHbp thermoregulation. Our results shed further light on mechanisms underlying the control of the production of this important virulence factor and vaccine antigen. PMID:27560142

  4. Oral Immunization with Recombinant Mycobacterium smegmatis Expressing the Outer Membrane Protein 26-Kilodalton Antigen Confers Prophylactic Protection against Helicobacter pylori Infection ▿ †

    OpenAIRE

    Lü, Lin; Zeng, Han-qing; Wang, Pi-Long; Shen, Wei; Xiang, Ting-xiu; Mei, Zhe-chuan

    2011-01-01

    Helicobacter pylori infection is prevalent worldwide and results in chronic gastritis, which may lead to gastric mucosa-associated lymphoid tissue lymphoma and gastric cancer. We have previously reported that oral immunization with recombinant Mycobacterium smegmatis expressing the H. pylori outer membrane protein 26-kilodalton (Omp26) antigen affords therapeutic protection against H. pylori infection in mice. In the present study, we investigated the prophylactic effects of this vaccine cand...

  5. Adenovirus vaccine vectors expressing hepatitis B surface antigen: importance of regulatory elements in the adenovirus major late intron.

    Science.gov (United States)

    Mason, B B; Davis, A R; Bhat, B M; Chengalvala, M; Lubeck, M D; Zandle, G; Kostek, B; Cholodofsky, S; Dheer, S; Molnar-Kimber, K

    1990-08-01

    Adenovirus types 4 and 7 are currently used as live oral vaccines for prevention of acute respiratory disease caused by these adenovirus serotypes. To investigate the concept of producing live recombinant vaccines using these serotypes, adenovirus types 4 (Ad4) and 7 (Ad7) were constructed that produce HBsAg upon infection of cell cultures. Ad4 recombinants were constructed that express HBsAg from a cassette inserted 135 bp from the right-hand terminus of the viral genome. The cassette contained the Ad4 major late promoter followed by leader 1 of the tripartite leader, the first intervening sequence between leaders 1 and 2, leaders 2 and 3, the HBsAg gene, and tandem polyadenylation signals from the Ad4 E3B and hexon genes. Using this same cassette, a series of Ad4 recombinants expressing HBsAg were constructed with deletions in the intervening sequence between leaders 1 and 2 to evaluate the contribution of the downstream control elements more precisely. Inclusion of regions located between +82 and +148 as well as +148 and +232 resulted in increases in expression levels of HBsAg in A549-infected cells by 22-fold and 44-fold, respectively, over the levels attained by an adenovirus recombinant retaining only sequences from +1 to +82, showing the importance of these elements in the activation of the major late promoter during the course of a natural Ad4 viral infection. Parallel increases were also observed in steady-state levels of cytoplasmic HBsAg-specific mRNA. When similar Ad7 recombinant viruses were constructed, these viruses also expressed 20-fold more HBsAg due to the presence of the intron. All Ad4 and Ad7 recombinants produced HBsAg particles containing gp27 and p24 which were secreted in the medium. When dogs were immunized intratracheally with one of these Ad7 recombinants, they seroconverted to both Ad7 and HBsAg to a high level. PMID:2371766

  6. Selection of glutamate-rich protein long synthetic peptides for vaccine development: antigenicity and relationship with clinical protection and immunogenicity.

    Science.gov (United States)

    Theisen, M; Dodoo, D; Toure-Balde, A; Soe, S; Corradin, G; Koram, K K; Kurtzhals, J A; Hviid, L; Theander, T; Akanmori, B; Ndiaye, M; Druilhe, P

    2001-09-01

    Antibodies against three long synthetic peptides (LSPs) derived from the glutamate-rich protein (GLURP) of Plasmodium falciparum were analyzed in three cohorts from Liberia, Ghana, and Senegal. Two overlapping LSPs, LR67 and LR68, are derived from the relatively conserved N-terminal nonrepeat region (R0), and the third, LR70, is derived from the R2 repeat region. A high prevalence of antibody responses to each LSP was observed in all three areas of endemic infection. Levels of cytophilic immunoglobulin G (IgG) antibodies against both GLURP regions were significantly correlated with protection from clinical P. falciparum malaria. Protected children from the Ghana cohort possessed predominantly IgG1 antibodies against the nonrepeat epitope and IgG3 antibodies against the repeat epitope. T-cell proliferation responses, studied in the cohort from Senegal, revealed that T-helper-cell epitopes were confined to the nonrepeat region. When used as immunogens, the LR67 and LR68 peptides elicited strong IgG responses in outbred mice and LR67 also induced antibodies in mice of different H-2 haplotypes, confirming the presence of T-helper-cell epitopes in these constructs. Mouse antipeptide antisera recognized parasite proteins as determined by immunofluorescence and immunoblotting. This indicates that synthetic peptides derived from relatively conserved epitopes of GLURP might serve as useful immunogens for vaccination against P. falciparum malaria. PMID:11500389

  7. Adjuvant Effect of Cationic Liposomes for Subunit Influenza Vaccine: Influence of Antigen Loading Method, Cholesterol and Immune Modulators

    Directory of Open Access Journals (Sweden)

    Alexander Kros

    2013-07-01

    Full Text Available Cationic liposomes are potential adjuvants for influenza vaccines. In a previous study we reported that among a panel of cationic liposomes loaded with influenza hemagglutinin (HA, DC-Chol:DPPC (1:1 molar ratio liposomes induced the strongest immune response. However, it is not clear whether the cholesterol (Chol backbone or the tertiary amine head group of DC-Chol was responsible for this. Therefore, in the present work we studied the influence of Chol in the lipid bilayer of cationic liposomes. Moreover, we investigated the effect of the HA loading method (adsorption versus encapsulation and the encapsulation of immune modulators in DC-Chol liposomes on the immunogenicity of HA. Liposomes consisting of a neutral lipid (DPPC or Chol and a cationic compound (DC-Chol, DDA, or eDPPC were produced by film hydration-extrusion with/without an encapsulated immune modulator (CpG or imiquimod. The liposomes generally showed comparable size distribution, zeta potential and HA loading. In vitro studies with monocyte-derived human dendritic cells and immunization studies in C57Bl/6 mice showed that: (1 liposome-adsorbed HA is more immunogenic than encapsulated HA; (2 the incorporation of Chol in the bilayer of cationic liposomes enhances their adjuvant effect; and (3 CpG loaded liposomes are more efficient at enhancing HA-specific humoral responses than plain liposomes or Alhydrogel.

  8. A liquid crystal of ascorbyl palmitate, used as vaccine platform, provides sustained release of antigen and has intrinsic pro-inflammatory and adjuvant activities which are dependent on MyD88 adaptor protein.

    Science.gov (United States)

    Sánchez Vallecillo, María F; Minguito de la Escalera, María M; Aguirre, María V; Ullio Gamboa, Gabriela V; Palma, Santiago D; González-Cintado, Leticia; Chiodetti, Ana L; Soldano, Germán; Morón, Gabriel; Allemandi, Daniel A; Ardavín, Carlos; Pistoresi-Palencia, María C; Maletto, Belkys A

    2015-09-28

    Modern subunit vaccines require the development of new adjuvant strategies. Recently, we showed that CpG-ODN formulated with a liquid crystal nanostructure formed by self-assembly of 6-O-ascorbyl palmitate (Coa-ASC16) is an attractive system for promoting an antigen-specific immune response to weak antigens. Here, we showed that after subcutaneous injection of mice with near-infrared fluorescent dye-labeled OVA antigen formulated with Coa-ASC16, the dye-OVA was retained at the injection site for a longer period than when soluble dye-OVA was administered. Coa-ASC16 alone elicited a local inflammation, but how this material triggers this response has not been described yet. Although it is known that some materials used as a platform are not immunologically inert, very few studies have directly focused on this topic. In this study, we explored the underlying mechanisms concerning the interaction between Coa-ASC16 and the immune system and we found that the whole inflammatory response elicited by Coa-ASC16 (leukocyte recruitment and IL-1β, IL-6 and IL-12 production) was dependent on the MyD88 protein. TLR2, TLR4, TLR7 and NLRP3-inflammasome signaling were not required for induction of this inflammatory response. Coa-ASC16 induced local release of self-DNA, and in TLR9-deficient mice IL-6 production was absent. In addition, Coa-ASC16 revealed an intrinsic adjuvant activity which was affected by MyD88 and IL-6 absence. Taken together these results indicate that Coa-ASC16 used as a vaccine platform is effective due to the combination of the controlled release of antigen and its intrinsic pro-inflammatory activity. Understanding how Coa-ASC16 works might have significant implications for rational vaccine design. PMID:26188153

  9. Assuring Access to Affordable Coverage

    Data.gov (United States)

    U.S. Department of Health & Human Services — Under the Affordable Care Act, millions of uninsured Americans will gain access to affordable coverage through Affordable Insurance Exchanges and improvements in...

  10. Discovery of dormancy associated antigens of Mycobacterium tuberculosis : novel targets for the development of post-exposure or therapeutic tuberculosis vaccines

    NARCIS (Netherlands)

    Lin, May Young

    2009-01-01

    The growing number of tuberculosis (TB) casualties urges development of not only more effective drugs and preventive vaccines but also development of post-exposure/therapeutic TB vaccines. Post-exposure/therapeutic TB vaccines are needed since 2 billion people worldwide harbor a latent Mycobacterium

  11. Cell Wall Anchoring of the Campylobacter Antigens to Lactococcus lactis.

    Science.gov (United States)

    Kobierecka, Patrycja A; Olech, Barbara; Książek, Monika; Derlatka, Katarzyna; Adamska, Iwona; Majewski, Paweł M; Jagusztyn-Krynicka, Elżbieta K; Wyszyńska, Agnieszka K

    2016-01-01

    Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein - CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type C. jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analyzed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ Lactic Acid Bacteria (LAB) strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered as an alternative vector to

  12. Cloning, expression and immunoprotective efficacy of rHaa86, the homologue of the Bm86 tick vaccine antigen, from Hyalomma anatolicum anatolicum.

    Science.gov (United States)

    Azhahianambi, P; De La Fuente, J; Suryanarayana, V V S; Ghosh, S

    2009-03-01

    The Bm86 homologue of Hyalomma anatolicum anatolicum Izatnagar isolate was cloned and expressed in methylotropic yeast Pichia pastoris as intracellular, glycosylated and particulated form. It was named as rHaa86, the first recombinant protein of H. a. anatolicum. Seven epidermal growth factor-like domains predicted in Haa86 were structurally similar with that of its Bm86 counterpart. The identity between the corresponding EGF like domains of Bm86 and Haa86 were ranging from 51.3% to 78.3%. The molecular weight of the rHaa86 was 120-140 kDa, with possible 50-70 kDa glycosylation. The purified rHaa86 was characterized immunologically and evaluated for its immunoprotective potential against homologous challenge infestation in three groups of cross-bred calves. The immediate rejection percentage of females of H. a. anatolicum was 36 5%, 12.4% and 10.1% fed on immunized (group 1), adjuvant control (group 2) and untreated control (group 3) calves, respectively. The percent rejection of female ticks fed on immunized calves was 24.1% and 26.4% higher than for the ticks fed on control groups 2 and 3, respectively (P < 0.05). The reduction of number of females, mean weight of eggs, adult females and efficacy of immunogen were 58.0%, 9.0%, 5.0% and 61.6%, respectively. The mean reproductive index of females fed on group 1 calves was significantly lower (P < 0.05) than the females fed on the control groups and 44% reduction in the number of engorged larvae was recorded from the group 1 calves. The data demonstrated that rHaa86 antigen based vaccine could serve as one of the effective components in the integrated control of H. a. anatolicum. PMID:19222782

  13. 猪囊尾蚴重组抗原和基因工程疫苗的研究进展%Research Progress for Recombinant Antigen and Genetic Engineering Vaccine of Cysticercosis

    Institute of Scientific and Technical Information of China (English)

    冯金瑞; 刘立军

    2012-01-01

    猪囊尾蚴病(Cysticercosis)是由猪带绦虫的幼虫囊尾蚴寄生于人或猪等而引起的人畜共患寄生虫病,是公认的世界经济病之一。严重威胁着人体健康,并给畜牧业造成重大经济损失,猪囊尾蚴病的免疫防治势在必行。然而在猪囊尾蚴病疫苗研究中,疫苗抗原的选择和来源一直困扰着兽医工作者。该文就近年来猪囊尾蚴病诊断重组抗原和基因工程疫苗的分子生物学研究进展进行了综述。%Cysticercosis,which is known as a social-economic disease in the world,is an important zoonosis infecting human and pig caused by Taenia solium larval Cysticercus cellulosae.This disease must be prevented for its influence on international competition of the meat product and the great economic loss.However,the choice and source of vaccinal antigen always puzzles veterinarians.This paper reviewed recent research progress in molecular biology of vaccine for Recombinant antigen and genetic engineering vaccine of cysticercosis.

  14. Affordable Vehicle Avionics Overview

    Science.gov (United States)

    Cockrell, James J.

    2015-01-01

    Public and private launch vehicle developers are reducing the cost of propulsion for small commercial launchers, but conventional high-performance, high-reliability avionics remain the disproportionately high cost driver for launch. AVA technology performs as well or better than conventional launch vehicle avionics, but with a fraction of the recurring costs. AVA enables small launch providers to offer affordable rides to LEO to nano-satellites as primary payloads meaning, small payloads can afford to specify their own launch and orbit parameters

  15. Study on the efficacy and safety of different antigens and oil formulations of infectious coryza vaccines containing an NAD-independent strain of Avibacterium paragallinarum

    Directory of Open Access Journals (Sweden)

    B. Dungu

    2009-09-01

    Full Text Available The present study was designed to assess and compare three different formulations of the new Onderstepoort infectious coryza (IC quadrivalent vaccine, which contain an NAD-independent strain of Avibacterium paragallinarum (previously known as Haemophilus paragallinarum, and a commercial IC vaccine, not containing an NAD-independent strain, for their safety and ability to protect chickens of varying ages against virulent challenges with four different serovars of A. paragallinarum, including the NAD-independent strain of the C-3 serovar. Four groups of 140 chickens each were vaccinated at the age of 17 weeks and revaccinated at the age of 19 weeks with each of the four vaccine formulations. A similar sized group of non-vaccinated chickens was used as control. Two rounds of challenge were conducted: a group of chicken in each vaccination group was challenged between 31 and 35 weeks of age, while another group was challenged between 51 and 55 weeks of age. The ''in-contact'' challenge model was used in this experiment. For each vaccination group, the four challenge strains representing four local serovars were used in each challenge round. The efficacy of the vaccines was compared based on overall protection levels obtained and the duration of protection. The safety of the different vaccines was determined by the severity of post-vaccination reactions. The need for the incorporation of the NAD-independent strain in the vaccine was evidenced by the low protection level against NAD-independent challenge recorded in the group of birds vaccinated with the commercial vaccine. The results obtained confirmed not only the variation in virulence of different South African serovars, with serovar C-3 being the most virulent and serovar B having almost no virulence but also the age related increase in susceptibility. The importance of a suitable formulation of the vaccine is discussed.

  16. Results from tandem Phase 1 studies evaluating the safety, reactogenicity and immunogenicity of the vaccine candidate antigen Plasmodium falciparum FVO merozoite surface protein-1 (MSP142 administered intramuscularly with adjuvant system AS01

    Directory of Open Access Journals (Sweden)

    Otsyula Nekoye

    2013-01-01

    Full Text Available Abstract Background The development of an asexual blood stage vaccine against Plasmodium falciparum malaria based on the major merozoite surface protein-1 (MSP1 antigen is founded on the protective efficacy observed in preclinical studies and induction of invasion and growth inhibitory antibody responses. The 42 kDa C-terminus of MSP1 has been developed as the recombinant protein vaccine antigen, and the 3D7 allotype, formulated with the Adjuvant System AS02A, has been evaluated extensively in human clinical trials. In preclinical rabbit studies, the FVO allele of MSP142 has been shown to have improved immunogenicity over the 3D7 allele, in terms of antibody titres as well as growth inhibitory activity of antibodies against both the heterologous 3D7 and homologous FVO parasites. Methods Two Phase 1 clinical studies were conducted to examine the safety, reactogenicity and immunogenicity of the FVO allele of MSP142 in the adjuvant system AS01 administered intramuscularly at 0-, 1-, and 2-months: one in the USA and, after evaluation of safety data results, one in Western Kenya. The US study was an open-label, dose escalation study of 10 and 50 μg doses of MSP142 in 26 adults, while the Kenya study, evaluating 30 volunteers, was a double-blind, randomized study of only the 50 μg dose with a rabies vaccine comparator. Results In these studies it was demonstrated that this vaccine formulation has an acceptable safety profile and is immunogenic in malaria-naïve and malaria-experienced populations. High titres of anti-MSP1 antibodies were induced in both study populations, although there was a limited number of volunteers whose serum demonstrated significant inhibition of blood-stage parasites as measured by growth inhibition assay. In the US volunteers, the antibodies generated exhibited better cross-reactivity to heterologous MSP1 alleles than a MSP1-based vaccine (3D7 allele previously tested at both study sites. Conclusions Given that the primary

  17. Assessment of packed bed bioreactor systems in the production of viral vaccines.

    Science.gov (United States)

    Rajendran, Ramya; Lingala, Rajendra; Vuppu, Siva Kumar; Bandi, Bala Obulapathi; Manickam, Elaiyaraja; Macherla, Sankar Rao; Dubois, Stéphanie; Havelange, Nicolas; Maithal, Kapil

    2014-01-01

    Vaccination is believed to be the most effective method for the prevention of infectious diseases. Thus it is imperative to develop cost effective and scalable process for the production of vaccines so as to make them affordable for mass use. In this study, performance of a novel disposable iCELLis fixed bed bioreactor system was investigated for the production of some viral vaccines like Rabies, Hepatitis-A and Chikungunya vaccines in comparison to conventional systems like the commercially available packed bed system and roller bottle system. Vero and MRC-5 cell substrates were evaluated for growth parameters in all the three systems maintaining similar seeding density, multiplicity of infection (MOI) and media components. It was observed that Vero cells showed similar growth in all the three bioreactors whereas MRC-5 cells showed better growth in iCELLis Nano system and roller bottle system. Subsequently, the virus infection and antigen production studies also revealed that for Hepatitis-A and Chikungunya iCELLis Nano bioreactor system was better to the commercial packed bed bioreactor and roller bottle systems. Although for rabies antigen production commercially available packed bed bioreactor system was found to be better. This study shows that different bioreactor platforms may be employed for viral vaccine production and iCELLis Nano is one of such new convenient and a stable platform for production of human viral vaccines. PMID:24949260

  18. Nanoparticles for nasal delivery of vaccines : monitoring adaptive immune responses

    NARCIS (Netherlands)

    Keijzer, C.

    2013-01-01

    The continuous emergence of new pathogens and growing drug resistance of microorganisms asks for innovative vaccination strategies. An alternative to conventional multiple injection vaccines is the nasal route of vaccine delivery. The immune response induced following nasal antigen delivery depends

  19. Vietnam Affordable Housing

    OpenAIRE

    World Bank Group

    2015-01-01

    Affordable housing will be instrumental to helping Vietnam achieve its goals for increasing productivity and inclusive urban growth. Since Doi Moi, the country has experienced impressive economic growth, averaged at 7.4 percent per annum from 1990 to 2008, lowering to an average of 6 percent per annum from 2007 to 2013. Strong economic growth has supported a substantial reduction in povert...

  20. Production of dengue virus envelope protein domain III-based antigens in tobacco chloroplasts using inducible and constitutive expression systems.

    Science.gov (United States)

    Gottschamel, Johanna; Lössl, Andreas; Ruf, Stephanie; Wang, Yanliang; Skaugen, Morten; Bock, Ralph; Clarke, Jihong Liu

    2016-07-01

    Dengue fever is a disease in many parts of the tropics and subtropics and about half the world's population is at risk of infection according to the World Health Organization. Dengue is caused by any of the four related dengue virus serotypes DEN-1, -2, -3 and -4, which are transmitted to people by Aedes aegypti mosquitoes. Currently there is only one vaccine (Dengvaxia(®)) available (limited to a few countries) on the market since 2015 after half a century's intensive efforts. Affordable and accessible vaccines against dengue are hence still urgently needed. The dengue envelop protein domain III (EDIII), which is capable of eliciting serotype-specific neutralizing antibodies, has become the focus for subunit vaccine development. To contribute to the development of an accessible and affordable dengue vaccine, in the current study we have used plant-based vaccine production systems to generate a dengue subunit vaccine candidate in tobacco. Chloroplast genome engineering was applied to express serotype-specific recombinant EDIII proteins in tobacco chloroplasts using both constitutive and ethanol-inducible expression systems. Expression of a tetravalent antigen fusion construct combining EDIII polypeptides from all four serotypes was also attempted. Transplastomic EDIII-expressing tobacco lines were obtained and homoplasmy was verified by Southern blot analysis. Northern blot analyses showed expression of EDIII antigen-encoding genes. EDIII protein accumulation levels varied for the different recombinant EDIII proteins and the different expression systems, and reached between 0.8 and 1.6 % of total cellular protein. Our study demonstrates the suitability of the chloroplast compartment as a production site for an EDIII-based vaccine candidate against dengue fever and presents a Gateway(®) plastid transformation vector for inducible transgene expression. PMID:27116001

  1. Enhanced effect of BCG vaccine against pulmonary Mycobacterium tuberculosis infection in mice with lung Th17 response to mycobacterial heparin-binding hemagglutinin adhesin antigen.

    Science.gov (United States)

    Fukui, Masayuki; Shinjo, Kikuko; Umemura, Masayuki; Shigeno, Satoko; Harakuni, Tetsuya; Arakawa, Takeshi; Matsuzaki, Goro

    2015-12-01

    Although the BCG vaccine can prevent tuberculosis (TB) in infants, its ability to prevent adult pulmonary TB is reportedly limited. Therefore, development of a novel effective vaccine against pulmonary TB has become an international research priority. We have previously reported that intranasal vaccination of mice with a mycobacterial heparin-binding hemagglutinin adhesin (HBHA) plus mucosal adjuvant cholera toxin (CT) enhances production of IFN-γ and anti-HBHA antibody and suppresses extrapulmonary bacterial dissemination after intranasal infection with BCG. In the present study, the effects of intranasal HBHA + CT vaccine on murine pulmonary Mycobacterium tuberculosis (Mtb) infection were examined. Intranasal HBHA + CT vaccination alone failed to reduce the bacterial burden in the infected lung. However, a combination vaccine consisting of s.c. BCG priming and an intranasal HBHA + CT booster significantly enhanced protective immunity against pulmonary Mtb infection on day 14 compared with BCG vaccine alone. Further, it was found that intranasal HBHA + CT vaccine enhanced not only IFN-γ but also IL-17A production by HBHA-specific T cells in the lung after pulmonary Mtb infection. Therefore, this combination vaccine may be a good candidate for a new vaccine strategy against pulmonary TB. PMID:26577130

  2. Optimising and evaluating the characteristics of a multiple antigen ELISA for detection of Mycobacterium bovis infection in a badger vaccine field trial.

    Directory of Open Access Journals (Sweden)

    Inma Aznar

    Full Text Available A long-term research programme has been underway in Ireland to evaluate the usefulness of badger vaccination as part of the national bTB (bovine tuberculosis control strategy. This culminated in a field trial which commenced in county Kilkenny in 2009 to determine the effects of badger vaccination on Mycobacterium bovis transmission in badgers under field conditions. In the present study, we sought to optimise the characteristics of a multiplex chemiluminescent assay for detection of M. bovis infection in live badgers. Our goal was to maximise specificity, and therefore statistical power, during evaluation of the badger vaccine trial data. In addition, we also aimed to explore the effects of vaccination on test characteristics. For the test optimisation, we ran a stepwise logistic regression with analytical weights on the converted Relative Light Units (RLU obtained from testing blood samples from 215 badgers captured as part of culling operations by the national Department of Agriculture, Food and the Marine (DAFM. The optimised test was applied to two other datasets obtained from two captive badger studies (Study 1 and Study 2, and the sensitivity and specificity of the test was attained separately for vaccinated and non-vaccinated badgers. During optimisation, test sensitivity was maximised (30.77%, while retaining specificity at 99.99%. When the optimised test was then applied to the captive badger studies data, we observed that test characteristics did not vary greatly between vaccinated and non-vaccinated badgers. However, a different time lag between infection and a positive test result was observed in vaccinated and non-vaccinated badgers. We propose that the optimized multiplex immunoassay be used to analyse the vaccine trial data. In relation to the difference in the time lag observed for vaccinated and non-vaccinated badgers, we also present a strategy to enable the test to be used during trial evaluation.

  3. Optimising and evaluating the characteristics of a multiple antigen ELISA for detection of Mycobacterium bovis infection in a badger vaccine field trial.

    Science.gov (United States)

    Aznar, Inma; Frankena, Klaas; More, Simon J; Whelan, Clare; Martin, Wayne; Gormley, Eamonn; Corner, Leigh A L; Murphy, Denise; De Jong, Mart C M

    2014-01-01

    A long-term research programme has been underway in Ireland to evaluate the usefulness of badger vaccination as part of the national bTB (bovine tuberculosis) control strategy. This culminated in a field trial which commenced in county Kilkenny in 2009 to determine the effects of badger vaccination on Mycobacterium bovis transmission in badgers under field conditions. In the present study, we sought to optimise the characteristics of a multiplex chemiluminescent assay for detection of M. bovis infection in live badgers. Our goal was to maximise specificity, and therefore statistical power, during evaluation of the badger vaccine trial data. In addition, we also aimed to explore the effects of vaccination on test characteristics. For the test optimisation, we ran a stepwise logistic regression with analytical weights on the converted Relative Light Units (RLU) obtained from testing blood samples from 215 badgers captured as part of culling operations by the national Department of Agriculture, Food and the Marine (DAFM). The optimised test was applied to two other datasets obtained from two captive badger studies (Study 1 and Study 2), and the sensitivity and specificity of the test was attained separately for vaccinated and non-vaccinated badgers. During optimisation, test sensitivity was maximised (30.77%), while retaining specificity at 99.99%. When the optimised test was then applied to the captive badger studies data, we observed that test characteristics did not vary greatly between vaccinated and non-vaccinated badgers. However, a different time lag between infection and a positive test result was observed in vaccinated and non-vaccinated badgers. We propose that the optimized multiplex immunoassay be used to analyse the vaccine trial data. In relation to the difference in the time lag observed for vaccinated and non-vaccinated badgers, we also present a strategy to enable the test to be used during trial evaluation. PMID:24983473

  4. Advances in the study of multivalent recombinant DNA vaccines utilizing the hepatitis B virus surface antigen gene%乙肝表面抗原载体多价重组核酸疫苗研究进展

    Institute of Scientific and Technical Information of China (English)

    肖婷; 郭根灵; 辛宪云; 魏庆宽

    2012-01-01

    研究表明,乙肝病毒的包膜蛋白HBsAg不仅可以作为疫苗的理想候选分子,还可作为基因工程疫苗的理想载体,用来成功构建多种重组核酸疫苗.本文概述了以乙肝表面抗原为载体,重组或联合其他病毒、寄生虫、细胞因子等其他基因制作多价核酸疫苗的研究进展.%Studies have shown that hepatitis B virus envelope protein HBsAg can be used as an ideal candidate molecule for vaccines and also as an ideal vehicle for genetically engineered vaccines to successfully build a variety of recombinant DNA vaccines. This article provides an overview of advances in recombinant DNA vaccines prepared by using hepatitis B virus surface antigen as a carrier to restructure or join it to other viruses, parasites, cell factors, or other genes.

  5. Governments, off-patent vaccines, smallpox and universal childhood vaccination.

    Science.gov (United States)

    Music, Stanley

    2010-01-22

    WHO is now celebrating more than 30 years of freedom from smallpox. What was originally seen as a victory over an ancient scourge can now be viewed as an epidemiologically driven programme to overcome governmental inertia and under-achievement in delivering an off-patent vaccine. Though efforts are accelerating global vaccine use, a plea is made to push the world's governments to commit to universal childhood vaccination via a proposed new programme. The latter should begin by exploiting a long list of ever more affordable off-patent vaccines, vaccines that can virtually eliminate the bulk of the world's current vaccine-preventable disease burden. PMID:19699330

  6. Recombinant influenza vaccines.

    Science.gov (United States)

    Sedova, E S; Shcherbinin, D N; Migunov, A I; Smirnov, Iu A; Logunov, D Iu; Shmarov, M M; Tsybalova, L M; Naroditskiĭ, B S; Kiselev, O I; Gintsburg, A L

    2012-10-01

    This review covers the problems encountered in the construction and production of new recombinant influenza vaccines. New approaches to the development of influenza vaccines are investigated; they include reverse genetics methods, production of virus-like particles, and DNA- and viral vector-based vaccines. Such approaches as the delivery of foreign genes by DNA- and viral vector-based vaccines can preserve the native structure of antigens. Adenoviral vectors are a promising gene-delivery platform for a variety of genetic vaccines. Adenoviruses can efficiently penetrate the human organism through mucosal epithelium, thus providing long-term antigen persistence and induction of the innate immune response. This review provides an overview of the practicability of the production of new recombinant influenza cross-protective vaccines on the basis of adenoviral vectors expressing hemagglutinin genes of different influenza strains. PMID:23346377

  7. Vaccines against leptospirosis.

    Science.gov (United States)

    Adler, Ben

    2015-