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Sample records for antigenic peptide vaccine

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

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    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.

  2. Photochemical Internalization of Peptide Antigens Provides a Novel Strategy to Realize Therapeutic Cancer Vaccination

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    Markus Haug

    2018-04-01

    Full Text Available Effective priming and activation of tumor-specific CD8+ cytotoxic T lymphocytes (CTLs is crucial for realizing the potential of therapeutic cancer vaccination. This requires cytosolic antigens that feed into the MHC class I presentation pathway, which is not efficiently achieved with most current vaccination technologies. Photochemical internalization (PCI provides an emerging technology to route endocytosed material to the cytosol of cells, based on light-induced disruption of endosomal membranes using a photosensitizing compound. Here, we investigated the potential of PCI as a novel, minimally invasive, and well-tolerated vaccination technology to induce priming of cancer-specific CTL responses to peptide antigens. We show that PCI effectively promotes delivery of peptide antigens to the cytosol of antigen-presenting cells (APCs in vitro. This resulted in a 30-fold increase in MHC class I/peptide complex formation and surface presentation, and a subsequent 30- to 100-fold more efficient activation of antigen-specific CTLs compared to using the peptide alone. The effect was found to be highly dependent on the dose of the PCI treatment, where optimal doses promoted maturation of immature dendritic cells, thus also providing an adjuvant effect. The effect of PCI was confirmed in vivo by the successful induction of antigen-specific CTL responses to cancer antigens in C57BL/6 mice following intradermal peptide vaccination using PCI technology. We thus show new and strong evidence that PCI technology holds great potential as a novel strategy for improving the outcome of peptide vaccines aimed at triggering cancer-specific CD8+ CTL responses.

  3. Anti-cancer vaccination by transdermal delivery of antigen peptide-loaded nanogels via iontophoresis.

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    Toyoda, Mao; Hama, Susumu; Ikeda, Yutaka; Nagasaki, Yukio; Kogure, Kentaro

    2015-04-10

    Transdermal vaccination with cancer antigens is expected to become a useful anti-cancer therapy. However, it is difficult to accumulate enough antigen in the epidermis for effective exposure to Langerhans cells because of diffusion into the skin and muscle. Carriers, such as liposomes and nanoparticles, may be useful for the prevention of antigen diffusion. Iontophoresis, via application of a small electric current, is a noninvasive and efficient technology for transdermal drug delivery. Previously, we succeeded in the iontophoretic transdermal delivery of liposomes encapsulating insulin, and accumulation of polymer-based nanoparticle nanogels in the stratum corneum of the skin. Therefore, in the present study, we examined the use of iontophoresis with cancer antigen gp-100 peptide KVPRNQDWL-loaded nanogels for anti-cancer vaccination. Iontophoresis resulted in the accumulation of gp-100 peptide and nanogels in the epidermis, and subsequent increase in the number of Langerhans cells in the epidermis. Moreover, tumor growth was significantly suppressed by iontophoresis of the antigen peptide-loaded nanogels. Thus, iontophoresis of the antigen peptide-loaded nanogels may serve as an effective transdermal delivery system for anti-cancer vaccination. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Peptide Vaccines for Leishmaniasis

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    Rory C. F. De Brito

    2018-05-01

    Full Text Available Due to an increase in the incidence of leishmaniases worldwide, the development of new strategies such as prophylactic vaccines to prevent infection and decrease the disease have become a high priority. Classic vaccines against leishmaniases were based on live or attenuated parasites or their subunits. Nevertheless, the use of whole parasite or their subunits for vaccine production has numerous disadvantages. Therefore, the use of Leishmania peptides to design more specific vaccines against leishmaniases seems promising. Moreover, peptides have several benefits in comparison with other kinds of antigens, for instance, good stability, absence of potentially damaging materials, antigen low complexity, and low-cost to scale up. By contrast, peptides are poor immunogenic alone, and they need to be delivered correctly. In this context, several approaches described in this review are useful to solve these drawbacks. Approaches, such as, peptides in combination with potent adjuvants, cellular vaccinations, adenovirus, polyepitopes, or DNA vaccines have been used to develop peptide-based vaccines. Recent advancements in peptide vaccine design, chimeric, or polypeptide vaccines and nanovaccines based on particles attached or formulated with antigenic components or peptides have been increasingly employed to drive a specific immune response. In this review, we briefly summarize the old, current, and future stands on peptide-based vaccines, describing the disadvantages and benefits associated with them. We also propose possible approaches to overcome the related weaknesses of synthetic vaccines and suggest future guidelines for their development.

  5. Peptide Vaccines for Leishmaniasis.

    Science.gov (United States)

    De Brito, Rory C F; Cardoso, Jamille M De O; Reis, Levi E S; Vieira, Joao F; Mathias, Fernando A S; Roatt, Bruno M; Aguiar-Soares, Rodrigo Dian D O; Ruiz, Jeronimo C; Resende, Daniela de M; Reis, Alexandre B

    2018-01-01

    Due to an increase in the incidence of leishmaniases worldwide, the development of new strategies such as prophylactic vaccines to prevent infection and decrease the disease have become a high priority. Classic vaccines against leishmaniases were based on live or attenuated parasites or their subunits. Nevertheless, the use of whole parasite or their subunits for vaccine production has numerous disadvantages. Therefore, the use of Leishmania peptides to design more specific vaccines against leishmaniases seems promising. Moreover, peptides have several benefits in comparison with other kinds of antigens, for instance, good stability, absence of potentially damaging materials, antigen low complexity, and low-cost to scale up. By contrast, peptides are poor immunogenic alone, and they need to be delivered correctly. In this context, several approaches described in this review are useful to solve these drawbacks. Approaches, such as, peptides in combination with potent adjuvants, cellular vaccinations, adenovirus, polyepitopes, or DNA vaccines have been used to develop peptide-based vaccines. Recent advancements in peptide vaccine design, chimeric, or polypeptide vaccines and nanovaccines based on particles attached or formulated with antigenic components or peptides have been increasingly employed to drive a specific immune response. In this review, we briefly summarize the old, current, and future stands on peptide-based vaccines, describing the disadvantages and benefits associated with them. We also propose possible approaches to overcome the related weaknesses of synthetic vaccines and suggest future guidelines for their development.

  6. Synthetic peptide vaccines: palmitoylation of peptide antigens by a thioester bond increases immunogenicity

    DEFF Research Database (Denmark)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many...... or an amide bond. It was found that these S-palmitoylated peptides were much more immunogenic than N-palmitoylated peptides and at least similar to KLH-conjugated peptides with respect to appearance and magnitude of induced antibodies (canine parvovirus) or immunocastration effect (gonadotropin...

  7. Oral Delivery of Probiotics Expressing Dendritic Cell-Targeting Peptide Fused with Porcine Epidemic Diarrhea Virus COE Antigen: A Promising Vaccine Strategy against PEDV.

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    Wang, Xiaona; Wang, Li; Huang, Xuewei; Ma, Sunting; Yu, Meiling; Shi, Wen; Qiao, Xinyuan; Tang, Lijie; Xu, Yigang; Li, Yijing

    2017-10-25

    Porcine epidemic diarrhea virus (PEDV), an enteric coronavirus, is the causative agent of porcine epidemic diarrhea (PED) that damages intestinal epithelial cells and results in severe diarrhea and dehydration in neonatal suckling pigs with up to 100% mortality. The oral vaccine route is reported as a promising approach for inducing protective immunity against PEDV invasion. Furthermore, dendritic cells (DCs), professional antigen-presenting cells, link humoral and cellular immune responses for homeostasis of the intestinal immune environment. In this study, in order to explore an efficient oral vaccine against PEDV infection, a mucosal DC-targeting oral vaccine was developed using Lactobacillus casei to deliver the DC-targeting peptide (DCpep) fused with the PEDV core neutralizing epitope (COE) antigen. This probiotic vaccine could efficiently elicit secretory immunoglobulin A (SIgA)-based mucosal and immunoglobulin G (IgG)-based humoral immune responses via oral vaccination in vivo. Significant differences ( p targeting peptide fused with PEDV COE antigen. This mucosal DC-targeting oral vaccine delivery effectively enhances vaccine antigen delivery efficiency, providing a useful strategy to induce efficient immune responses against PEDV infection.

  8. Computational identification, characterization and validation of potential antigenic peptide vaccines from hrHPVs E6 proteins using immunoinformatics and computational systems biology approaches.

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    Abbas Khan

    Full Text Available High-risk human papillomaviruses (hrHPVs are the most prevalent viruses in human diseases including cervical cancers. Expression of E6 protein has already been reported in cervical cancer cases, excluding normal tissues. Continuous expression of E6 protein is making it ideal to develop therapeutic vaccines against hrHPVs infection and cervical cancer. Therefore, we carried out a meta-analysis of multiple hrHPVs to predict the most potential prophylactic peptide vaccines. In this study, immunoinformatics approach was employed to predict antigenic epitopes of hrHPVs E6 proteins restricted to 12 Human HLAs to aid the development of peptide vaccines against hrHPVs. Conformational B-cell and CTL epitopes were predicted for hrHPVs E6 proteins using ElliPro and NetCTL. The potential of the predicted peptides were tested and validated by using systems biology approach considering experimental concentration. We also investigated the binding interactions of the antigenic CTL epitopes by using docking. The stability of the resulting peptide-MHC I complexes was further studied by molecular dynamics simulations. The simulation results highlighted the regions from 46-62 and 65-76 that could be the first choice for the development of prophylactic peptide vaccines against hrHPVs. To overcome the worldwide distribution, the predicted epitopes restricted to different HLAs could cover most of the vaccination and would help to explore the possibility of these epitopes for adaptive immunotherapy against HPVs infections.

  9. Peptide Vaccine: Progress and Challenges

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    Weidang Li

    2014-07-01

    Full Text Available Conventional vaccine strategies have been highly efficacious for several decades in reducing mortality and morbidity due to infectious diseases. The bane of conventional vaccines, such as those that include whole organisms or large proteins, appear to be the inclusion of unnecessary antigenic load that, not only contributes little to the protective immune response, but complicates the situation by inducing allergenic and/or reactogenic responses. Peptide vaccines are an attractive alternative strategy that relies on usage of short peptide fragments to engineer the induction of highly targeted immune responses, consequently avoiding allergenic and/or reactogenic sequences. Conversely, peptide vaccines used in isolation are often weakly immunogenic and require particulate carriers for delivery and adjuvanting. In this article, we discuss the specific advantages and considerations in targeted induction of immune responses by peptide vaccines and progresses in the development of such vaccines against various diseases. Additionally, we also discuss the development of particulate carrier strategies and the inherent challenges with regard to safety when combining such technologies with peptide vaccines.

  10. Polymeric nanoparticles for co-delivery of synthetic long peptide antigen and poly IC as therapeutic cancer vaccine formulation

    NARCIS (Netherlands)

    Rahimian, Sima; Fransen, Marieke F.; Kleinovink, Jan Willem; Christensen, Jonatan Riis; Amidi, Maryam|info:eu-repo/dai/nl/304834912; Hennink, Wim E.|info:eu-repo/dai/nl/070880409; Ossendorp, Ferry

    2015-01-01

    The aim of the current study was to develop a cancer vaccine formulation for treatment of human papillomavirus (HPV)-induced malignancies. Synthetic long peptides (SLPs) derived from HPV16 E6 and E7 oncoproteins have been used for therapeutic vaccination in clinical trials with promising results. In

  11. A Large Size Chimeric Highly Immunogenic Peptide Presents Multistage Plasmodium Antigens as a Vaccine Candidate System against Malaria.

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    Lozano, José Manuel; Varela, Yahson; Silva, Yolanda; Ardila, Karen; Forero, Martha; Guasca, Laura; Guerrero, Yuly; Bermudez, Adriana; Alba, Patricia; Vanegas, Magnolia; Patarroyo, Manuel Elkin

    2017-11-01

    Rational strategies for obtaining malaria vaccine candidates should include not only a proper selection of target antigens for antibody stimulation, but also a versatile molecular design based on ordering the right pieces from the complex pathogen molecular puzzle towards more active and functional immunogens. Classical Plasmodium falciparum antigens regarded as vaccine candidates have been selected as model targets in this study. Among all possibilities we have chosen epitopes of Pf CSP, STARP; MSA1 and Pf 155/RESA from pre- and erythrocyte stages respectively for designing a large 82-residue chimeric immunogen. A number of options aimed at diminishing steric hindrance for synthetic procedures were assessed based on standard Fmoc chemistry such as building block orthogonal ligation; pseudo-proline and microwave-assisted procedures, therefore the large-chimeric target was produced, characterized and immunologically tested. Antigenicity and functional in vivo efficacy tests of the large-chimera formulations administered alone or as antigen mixtures have proven the stimulation of high antibody titers, showing strong correlation with protection and parasite clearance of vaccinated BALB/c mice after being lethally challenged with both P. berghei -ANKA and P. yoelii 17XL malaria strains. Besides, 3D structure features shown by the large-chimera encouraged as to propose using these rational designed large synthetic molecules as reliable vaccine candidate-presenting systems.

  12. A Large Size Chimeric Highly Immunogenic Peptide Presents Multistage Plasmodium Antigens as a Vaccine Candidate System against Malaria

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    José Manuel Lozano

    2017-11-01

    Full Text Available Rational strategies for obtaining malaria vaccine candidates should include not only a proper selection of target antigens for antibody stimulation, but also a versatile molecular design based on ordering the right pieces from the complex pathogen molecular puzzle towards more active and functional immunogens. Classical Plasmodium falciparum antigens regarded as vaccine candidates have been selected as model targets in this study. Among all possibilities we have chosen epitopes of PfCSP, STARP; MSA1 and Pf155/RESA from pre- and erythrocyte stages respectively for designing a large 82-residue chimeric immunogen. A number of options aimed at diminishing steric hindrance for synthetic procedures were assessed based on standard Fmoc chemistry such as building block orthogonal ligation; pseudo-proline and microwave-assisted procedures, therefore the large-chimeric target was produced, characterized and immunologically tested. Antigenicity and functional in vivo efficacy tests of the large-chimera formulations administered alone or as antigen mixtures have proven the stimulation of high antibody titers, showing strong correlation with protection and parasite clearance of vaccinated BALB/c mice after being lethally challenged with both P. berghei-ANKA and P. yoelii 17XL malaria strains. Besides, 3D structure features shown by the large-chimera encouraged as to propose using these rational designed large synthetic molecules as reliable vaccine candidate-presenting systems.

  13. Therapeutic HIV Peptide Vaccine

    DEFF Research Database (Denmark)

    Fomsgaard, Anders

    2015-01-01

    Therapeutic vaccines aim to control chronic HIV infection and eliminate the need for lifelong antiretroviral therapy (ART). Therapeutic HIV vaccine is being pursued as part of a functional cure for HIV/AIDS. We have outlined a basic protocol for inducing new T cell immunity during chronic HIV-1...... infection directed to subdominant conserved HIV-1 epitopes restricted to frequent HLA supertypes. The rationale for selecting HIV peptides and adjuvants are provided. Peptide subunit vaccines are regarded as safe due to the simplicity, quality, purity, and low toxicity. The caveat is reduced immunogenicity...

  14. NOG-hIL-4-Tg, a new humanized mouse model for producing tumor antigen-specific IgG antibody by peptide vaccination.

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    Yoshie Kametani

    Full Text Available Immunodeficient mice transplanted with human peripheral blood mononuclear cells (PBMCs are promising tools to evaluate human immune responses to vaccines. However, these mice usually develop severe graft-versus-host disease (GVHD, which makes estimation of antigen-specific IgG production after antigen immunization difficult. To evaluate antigen-specific IgG responses in PBMC-transplanted immunodeficient mice, we developed a novel NOD/Shi-scid-IL2rγnull (NOG mouse strain that systemically expresses the human IL-4 gene (NOG-hIL-4-Tg. After human PBMC transplantation, GVHD symptoms were significantly suppressed in NOG-hIL-4-Tg compared to conventional NOG mice. In kinetic analyses of human leukocytes, long-term engraftment of human T cells has been observed in peripheral blood of NOG-hIL-4-Tg, followed by dominant CD4+ T rather than CD8+ T cell proliferation. Furthermore, these CD4+ T cells shifted to type 2 helper (Th2 cells, resulting in long-term suppression of GVHD. Most of the human B cells detected in the transplanted mice had a plasmablast phenotype. Vaccination with HER2 multiple antigen peptide (CH401MAP or keyhole limpet hemocyanin (KLH successfully induced antigen-specific IgG production in PBMC-transplanted NOG-hIL-4-Tg. The HLA haplotype of donor PBMCs might not be relevant to the antibody secretion ability after immunization. These results suggest that the human PBMC-transplanted NOG-hIL-4-Tg mouse is an effective tool to evaluate the production of antigen-specific IgG antibodies.

  15. An M2e-based multiple antigenic peptide vaccine protects mice from lethal challenge with divergent H5N1 influenza viruses

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    Chan Chris CS

    2010-01-01

    Full Text Available Abstract Background A growing concern has raised regarding the pandemic potential of the highly pathogenic avian influenza (HPAI H5N1 viruses. Consequently, there is an urgent need to develop an effective and safe vaccine against the divergent H5N1 influenza viruses. In the present study, we designed a tetra-branched multiple antigenic peptide (MAP-based vaccine, designated M2e-MAP, which contains the sequence overlapping the highly conserved extracellular domain of matrix protein 2 (M2e of a HPAI H5N1 virus, and investigated its immune responses and cross-protection against different clades of H5N1 viruses. Results Our results showed that M2e-MAP vaccine induced strong M2e-specific IgG antibody responses following 3-dose immunization of mice with M2e-MAP in the presence of Freunds' or aluminium (alum adjuvant. M2e-MAP vaccination limited viral replication and attenuated histopathological damage in the challenged mouse lungs. The M2e-MAP-based vaccine protected immunized mice against both clade1: VN/1194 and clade2.3.4: SZ/406H H5N1 virus challenge, being able to counteract weight lost and elevate survival rate following lethal challenge of H5N1 viruses. Conclusions These results suggest that M2e-MAP presenting M2e of H5N1 virus has a great potential to be developed into an effective subunit vaccine for the prevention of infection by a broad spectrum of HPAI H5N1 viruses.

  16. Effective clinical-scale production of dendritic cell vaccines by monocyte elutriation directly in medium, subsequent culture in bags and final antigen loading using peptides or RNA transfection.

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    Erdmann, Michael; Dörrie, Jan; Schaft, Niels; Strasser, Erwin; Hendelmeier, Martin; Kämpgen, Eckhart; Schuler, Gerold; Schuler-Thurner, Beatrice

    2007-09-01

    Dendritic cell (DC) vaccination approaches are advancing fast into the clinic. The major obstacle for further improvement is the current lack of a simple functionally "closed" system to generate standardized monocyte-derived (mo) DC vaccines. Here, we significantly optimized the use of the Elutra counterflow elutriation system to enrich monocytic DC precursors by (1) developing an algorithm to avoid red blood cell debulking and associated monocyte loss before elutriation, and (2) by elutriation directly in culture medium rather than phosphate-buffered saline. Upon elutriation the bags containing the collected monocytes are simply transferred into the incubator to generate DC progeny as the final "open" washing step is no longer required. Elutriation resulted in significantly more (> or = 2-fold) and purer DC than the standard gradient centrifugation/adherence-based monocyte enrichment, whereas morphology, maturation markers, viability, migratory capacity, and T cell stimulatory capacity were identical. Subsequently, we compared RNA transfection, as this is an increasingly used approach to load DC with antigen. Elutra-derived and adherence-derived DC could be electroporated with similar, high efficiency (on average >85% green fluorescence protein positive), and appeared also equal in antigen expression kinetics. Both Elutra-derived and adherence-derived DC, when loaded with the MelanA peptide or electroporated with MelanA RNA, showed a high T cell stimulation capacity, that is, priming of MelanA-specific CD8+ T cells. Our optimized Elutra-based procedure is straightforward, clearly superior to the standard gradient centrifugation/plastic adherence protocol, and now allows the generation of large numbers of peptide-loaded or RNA-transfected DC in a functionally closed system.

  17. High-affinity human leucocyte antigen class I binding variola-derived peptides induce CD4(+) T cell responses more than 30 years post-vaccinia virus vaccination

    DEFF Research Database (Denmark)

    Wang, M.; Tang, Sheila Tuyet; Lund, Ole

    2009-01-01

    Interferon-gamma secreting T lymphocytes against pox virus-derived synthetic 9-mer peptides were tested by enzyme-linked immunospot in peripheral blood of individuals vaccinated with vaccinia virus more than 30 years ago. The peptides were characterized biochemically as high-affinity human leucoc...

  18. Liposome-based synthetic long peptide vaccines for cancer immunotherapy

    NARCIS (Netherlands)

    Varypataki, E.M.

    2016-01-01

    Synthetic long peptides (SLP) derived from cancer-associated antigens hold great promise as well-defined antigens for cancer immunotherapy. Clinical studies showed that SLP vaccines have functional potency when applied to pre-malignant stage patients, but need to be improved for use as a therapeutic

  19. Idala: An unnamed Function Peptide Vaccine for Tuberculosis ...

    African Journals Online (AJOL)

    Purpose: To evaluate Myt272 protein antigenicity and immunogenicity by trial vaccination in mice and its in silico analysis as a potential peptide vaccine for tuberculosis. Methods: Myt272 gene, which has 100 % identity with Mycobacterium tuberculosis H37Rv unknown function gene Rv3424c, was ligated by genomic ...

  20. Selection of glutamate-rich protein long synthetic peptides for vaccine development: antigenicity and relationship with clinical protection and immunogenicity

    DEFF Research Database (Denmark)

    Theisen, M; Dodoo, D; Toure-Balde, A

    2001-01-01

    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...

  1. Vaccination with NY-ESO-1 overlapping peptides mixed with Picibanil OK-432 and montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

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    Wada, Hisashi; Isobe, Midori; Kakimi, Kazuhiro; Mizote, Yu; Eikawa, Shingo; Sato, Eiichi; Takigawa, Nagio; Kiura, Katsuyuki; Tsuji, Kazuhide; Iwatsuki, Keiji; Yamasaki, Makoto; Miyata, Hiroshi; Matsushita, Hirokazu; Udono, Heiichiro; Seto, Yasuyuki; Yamada, Kazuhiro; Nishikawa, Hiroyoshi; Pan, Linda; Venhaus, Ralph; Oka, Mikio; Doki, Yuichiro; Nakayama, Eiichi

    2014-01-01

    We conducted a clinical trial of an NY-ESO-1 cancer vaccine using 4 synthetic overlapping long peptides (OLP; peptides #1, 79-108; #2, 100-129; #3, 121-150; and #4, 142-173) that include a highly immunogenic region of the NY-ESO-1 molecule. Nine patients were immunized with 0.25 mg each of three 30-mer and a 32-mer long NY-ESO-1 OLP mixed with 0.2 KE Picibanil OK-432 and 1.25 mL Montanide ISA-51. The primary endpoints of this study were safety and NY-ESO-1 immune responses. Five to 18 injections of the NY-ESO-1 OLP vaccine were well tolerated. Vaccine-related adverse events observed were fever and injection site reaction (grade 1 and 2). Two patients showed stable disease after vaccination. An NY-ESO-1-specific humoral immune response was observed in all patients and an antibody against peptide #3 (121-150) was detected firstly and strongly after vaccination. NY-ESO-1 CD4 and CD8 T-cell responses were elicited in these patients and their epitopes were identified. Using a multifunctional cytokine assay, the number of single or double cytokine-producing cells was increased in NY-ESO-1-specific CD4 and CD8 T cells after vaccination. Multiple cytokine-producing cells were observed in PD-1 (-) and PD-1 (+) CD4 T cells. In conclusion, our study indicated that the NY-ESO-1 OLP vaccine mixed with Picibanil OK-432 and Montanide ISA-51 was well tolerated and elicited NY-ESO-1-specific humoral and CD4 and CD8 T-cell responses in immunized patients.

  2. Vaccination and the TAP-independent antigen processing pathways.

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    López, Daniel; Lorente, Elena; Barriga, Alejandro; Johnstone, Carolina; Mir, Carmen

    2013-09-01

    The cytotoxic CD8(+) T lymphocyte-mediated cellular response is important for the elimination of virus-infected cells and requires the prior recognition of short viral peptide antigens previously translocated to the endoplasmic reticulum by the transporter associated with antigen processing (TAP). However, individuals with nonfunctional TAP complexes or infected cells with TAP molecules blocked by specific viral proteins, such as the cowpoxvirus, a component of the first source of early empirical vaccination against smallpox, are still able to present several HLA class I ligands generated by the TAP-independent antigen processing pathways to specific cytotoxic CD8(+) T lymphocytes. Currently, bioterrorism and emerging infectious diseases have renewed interest in poxviruses. Recent works that have identified HLA class I ligands and epitopes in virus-infected TAP-deficient cells have implications for the study of both the effectiveness of early empirical vaccination and the analysis of HLA class I antigen processing in TAP-deficient subjects.

  3. Vaccine Adjuvant Incorporation Strategy Dictates Peptide Amphiphile Micelle Immunostimulatory Capacity.

    Science.gov (United States)

    Zhang, Rui; Kramer, Jake S; Smith, Josiah D; Allen, Brittany N; Leeper, Caitlin N; Li, Xiaolei; Morton, Logan D; Gallazzi, Fabio; Ulery, Bret D

    2018-06-01

    Current vaccine research has shifted from traditional vaccines (i.e., whole-killed or live-attenuated) to subunit vaccines (i.e., protein, peptide, or DNA) as the latter is much safer due to delivering only the bioactive components necessary to produce a desirable immune response. Unfortunately, subunit vaccines are very weak immunogens requiring delivery vehicles and the addition of immunostimulatory molecules termed adjuvants to convey protective immunity. An interesting type of delivery vehicle is peptide amphiphile micelles (PAMs), unique biomaterials where the vaccine is part of the nanomaterial itself. Due to the modularity of PAMs, they can be readily modified to deliver both vaccine antigens and adjuvants within a singular construct. Through the co-delivery of a model antigenic epitope (Ovalbumin 319-340 -OVA BT ) and a known molecular adjuvant (e.g., 2,3-dipalmitoyl-S-glyceryl cysteine-Pam 2 C), greater insight into the mechanisms by which PAMs can exert immunostimulatory effects was gained. It was found that specific combinations of antigen and adjuvant can significantly alter vaccine immunogenicity both in vitro and in vivo. These results inform fundamental design rules that can be leveraged to fabricate optimal PAM-based vaccine formulations for future disease-specific applications. Graphical Abstract.

  4. Inactivation and purification of cowpea mosaic virus-like particles displaying peptide antigens from Bacillus anthracis

    OpenAIRE

    Phelps, Jamie P.; Dang, Nghiep; Rasochova, Lada

    2007-01-01

    Chimeric cowpea mosaic virus (CPMV) particles displaying foreign peptide antigens on the particle surface are suitable for development of peptide-based vaccines. However, commonly used PEG precipitation-based purification methods are not sufficient for production of high quality vaccine candidates because they do not allow for separation of chimeric particles from cleaved contaminating species. Moreover, the purified particles remain infectious to plants. To advance the CPMV technology furthe...

  5. 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.

  6. Cellular vaccines in listeriosis: role of the Listeria antigen GAPDH

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    Calderón-González, Ricardo; Frande-Cabanes, Elisabet; Bronchalo-Vicente, Lucía; Lecea-Cuello, M. Jesús; Pareja, Eduardo; Bosch-Martínez, Alexandre; Fanarraga, Mónica L.; Yañez-Díaz, Sonsoles; Carrasco-Marín, Eugenio; Álvarez-Domínguez, Carmen

    2014-01-01

    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. PMID:24600592

  7. Unusual antigen presentation offers new insight into HIV vaccine design.

    Science.gov (United States)

    McMichael, Andrew J; Picker, Louis J

    2017-06-01

    Recent findings with a rhesus monkey cytomegalovirus based simian immunodeficiency virus vaccine have identified strong CD8+ T cell responses that are restricted by MHC-E. Also mycobacteria specific CD8+ T cells, that are MHC-E restricted, have been identified. MHC-E therefore can present a wide range of epitope peptides to CD8+ T cells, alongside its well defined role in presenting a conserved MHC-class I signal peptide to the NKG2A/C-CD94 receptor on natural killer cells. Here we explore the antigen processing pathways involved in these atypical T cell responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. An Overview on the Field of Micro- and Nanotechnologies for Synthetic Peptide-Based Vaccines

    Directory of Open Access Journals (Sweden)

    Aiala Salvador

    2011-01-01

    Full Text Available The development of synthetic peptide-based vaccines has many advantages in comparison with vaccines based on live attenuated organisms, inactivated or killed organism, or toxins. Peptide-based vaccines cannot revert to a virulent form, allow a better conservation, and are produced more easily and safely. However, they generate a weaker immune response than other vaccines, and the inclusion of adjuvants and/or the use of vaccine delivery systems is almost always needed. Among vaccine delivery systems, micro- and nanoparticulated ones are attractive, because their particulate nature can increase cross-presentation of the peptide. In addition, they can be passively or actively targeted to antigen presenting cells. Furthermore, particulate adjuvants are able to directly activate innate immune system in vivo. Here, we summarize micro- and nanoparticulated vaccine delivery systems used in the field of synthetic peptide-based vaccines as well as strategies to increase their immunogenicity.

  9. 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....

  10. Increasing vaccine potency through exosome antigen targeting.

    Science.gov (United States)

    Hartman, Zachary C; Wei, Junping; Glass, Oliver K; Guo, Hongtao; Lei, Gangjun; Yang, Xiao-Yi; Osada, Takuya; Hobeika, Amy; Delcayre, Alain; Le Pecq, Jean-Bernard; Morse, Michael A; Clay, Timothy M; Lyerly, Herbert K

    2011-11-21

    While many tumor associated antigens (TAAs) have been identified in human cancers, efforts to develop efficient TAA "cancer vaccines" using classical vaccine approaches have been largely ineffective. Recently, a process to specifically target proteins to exosomes has been established which takes advantage of the ability of the factor V like C1C2 domain of lactadherin to specifically address proteins to exosomes. Using this approach, we hypothesized that TAAs could be targeted to exosomes to potentially increase their immunogenicity, as exosomes have been demonstrated to traffic to antigen presenting cells (APC). To investigate this possibility, we created adenoviral vectors expressing the extracellular domain (ECD) of two non-mutated TAAs often found in tumors of cancer patients, carcinoembryonic antigen (CEA) and HER2, and coupled them to the C1C2 domain of lactadherin. We found that these C1C2 fusion proteins had enhanced expression in exosomes in vitro. We saw significant improvement in antigen specific immune responses to each of these antigens in naïve and tolerant transgenic animal models and could further demonstrate significantly enhanced therapeutic anti-tumor effects in a human HER2+ transgenic animal model. These findings demonstrate that the mode of secretion and trafficking can influence the immunogenicity of different human TAAs, and may explain the lack of immunogenicity of non-mutated TAAs found in cancer patients. They suggest that exosomal targeting could enhance future anti-tumor vaccination protocols. This targeting exosome process could also be adapted for the development of more potent vaccines in some viral and parasitic diseases where the classical vaccine approach has demonstrated limitations. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. 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

  12. A phase I study of vaccination with NY-ESO-1f peptide mixed with Picibanil OK-432 and Montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

    Science.gov (United States)

    Kakimi, Kazuhiro; Isobe, Midori; Uenaka, Akiko; Wada, Hisashi; Sato, Eiichi; Doki, Yuichiro; Nakajima, Jun; Seto, Yasuyuki; Yamatsuji, Tomoki; Naomoto, Yoshio; Shiraishi, Kenshiro; Takigawa, Nagio; Kiura, Katsuyuki; Tsuji, Kazuhide; Iwatsuki, Keiji; Oka, Mikio; Pan, Linda; Hoffman, Eric W; Old, Lloyd J; Nakayama, Eiichi

    2011-12-15

    We conducted a phase I clinical trial of a cancer vaccine using a 20-mer NY-ESO-1f peptide (NY-ESO-1 91-110) that includes multiple epitopes recognized by antibodies, and CD4 and CD8 T cells. Ten patients were immunized with 600 μg of NY-ESO-1f peptide mixed with 0.2 KE Picibanil OK-432 and 1.25 ml Montanide ISA-51. Primary end points of the study were safety and immune response. Subcutaneous injection of the NY-ESO-1f peptide vaccine was well tolerated. Vaccine-related adverse events observed were fever (Grade 1), injection-site reaction (Grade 1 or 2) and induration (Grade 2). Vaccination with the NY-ESO-1f peptide resulted in an increase or induction of NY-ESO-1 antibody responses in nine of ten patients. The sera reacted with recombinant NY-ESO-1 whole protein as well as the NY-ESO-1f peptide. An increase in CD4 and CD8 T cell responses was observed in nine of ten patients. Vaccine-induced CD4 and CD8 T cells responded to NY-ESO-1 91-108 in all patients with various HLA types with a less frequent response to neighboring peptides. The findings indicate that the 20-mer NY-ESO-1f peptide includes multiple epitopes recognized by CD4 and CD8 T cells with distinct specificity. Of ten patients, two with lung cancer and one with esophageal cancer showed stable disease. Our study shows that the NY-ESO-1f peptide vaccine was well tolerated and elicited humoral, CD4 and CD8 T cell responses in immunized patients. Copyright © 2011 UICC.

  13. Heterologous expression of antigenic peptides in Bacillus subtilis biofilms.

    Science.gov (United States)

    Vogt, Cédric M; Schraner, Elisabeth M; Aguilar, Claudio; Eichwald, Catherine

    2016-08-11

    Numerous strategies have been developed for the display of heterologous proteins in the surface of live bacterial carriers, which can be used as vaccines, immune-modulators, cancer therapy or bioremediation. Bacterial biofilms have emerged as an interesting approach for the expression of proteins of interest. Bacillus subtilis is a well-described, endospore-forming organism that is able to form biofilms and also used as a probiotic, thus making it a suitable candidate for the display of heterologous proteins within the biofilm. Here, we describe the use of TasA, an important structural component of the biofilms formed by B. subtilis, as a genetic tool for the display of heterologous proteins. We first engineered the fusion protein TasA-mCherry and showed that was widely deployed within the B. subtilis biofilms. A significant enhancement of the expression of TasA-mCherry within the biofilm was obtained when depleting both tasA and sinR genes. We subsequently engineered fusion proteins of TasA to antigenic peptides of the E. granulosus parasite, paramyosin and tropomyosin. Our results show that the antigens were well expressed within the biofilm as denoted by macrostructure complementation and by the detection of the fusion protein in both immunoblot and immunohistochemistry. In addition, we show that the recombinant endospores of B. subtilis preserve their biophysical and morphological properties. In this work we provide strong evidence pointing that TasA is a suitable candidate for the display of heterologous peptides, such as antigens, cytokines, enzymes or antibodies, in the B. subtilis biofilms. Finally, our data portray that the recombinant endospores preserve their morphological and biophysical properties and could be an excellent tool to facilitate the transport and the administration.

  14. A novel multi-antigen virally vectored vaccine against Mycobacterium avium subspecies paratuberculosis.

    Science.gov (United States)

    Bull, Tim J; Gilbert, Sarah C; Sridhar, Saranya; Linedale, Richard; Dierkes, Nicola; Sidi-Boumedine, Karim; Hermon-Taylor, John

    2007-11-28

    Mycobacterium avium subspecies paratuberculosis causes systemic infection and chronic intestinal inflammation in many species including primates. Humans are exposed through milk and from sources of environmental contamination. Hitherto, the only vaccines available against Mycobacterium avium subspecies paratuberculosis have been limited to veterinary use and comprised attenuated or killed organisms. We developed a vaccine comprising a fusion construct designated HAV, containing components of two secreted and two cell surface Mycobacterium avium subspecies paratuberculosis proteins. HAV was transformed into DNA, human Adenovirus 5 (Ad5) and Modified Vaccinia Ankara (MVA) delivery vectors. Full length expression of the predicted 95 kDa fusion protein was confirmed. Vaccination of naïve and Mycobacterium avium subspecies paratuberculosis infected C57BL/6 mice using DNA-prime/MVA-boost or Ad5-prime/MVA-boost protocols was highly immunogenic resulting in significant IFN-gamma ELISPOT responses by splenocytes against recombinant vaccine antigens and a range of HAV specific peptides. This included strong recognition of a T-cell epitope GFAEINPIA located near the C-terminus of the fusion protein. Antibody responses to recombinant vaccine antigens and HAV specific peptides but not GFAEINPIA, also occurred. No immune recognition of vaccine antigens occurred in any sham vaccinated Mycobacterium avium subspecies paratuberculosis infected mice. Vaccination using either protocol significantly attenuated pre-existing Mycobacterium avium subspecies paratuberculosis infection measured by qPCR in spleen and liver and the Ad5-prime/MVA-boost protocol also conferred some protection against subsequent challenge. No adverse effects of vaccination occurred in any of the mice. A range of modern veterinary and clinical vaccines for the treatment and prevention of disease caused by Mycobacterium avium subspecies paratuberculosis are needed. The present vaccine proved to be highly

  15. Evaluation of MAP-specific peptides following vaccination of goats

    DEFF Research Database (Denmark)

    Lybeck, Kari; Sjurseth, Siri K.; Melvang, Heidi Mikkelsen

    species or 2) selected based on “experience”. Peptides predicted to bind bovine MHC II by in silico analysis were included in further studies, resulting in two panels 1) genome-based and 2) selected. Initially, two groups of 15 healthy goats were vaccinated with one of the two panels (50 µg/peptide in CAF......01 adjuvant/CAF04 for boosting). Four MAP-infected goats were also vaccinated. In a second vaccination trail, groups of 8 healthy goat kids were vaccinated with genome-based peptides, selected peptides or selected peptides linked together in a recombinant protein (20 µg/peptide or 50 µg protein...... peptides. IFN-γ responses in healthy goats after the first vaccination were low, but testing of T cell lines from MAP-infected goats identified peptides inducing strong proliferative responses. Peptides for a second vaccination were selected by combining results from this study with a parallel cattle study...

  16. Dissecting antigen processing and presentation routes in dermal vaccination strategies

    NARCIS (Netherlands)

    Platteel, Anouk C M; Henri, Sandrine; Zaiss, Dietmar M; Sijts, Alice J A M

    2017-01-01

    The skin is an attractive site for vaccination due to its accessibility and presence of immune cells surveilling this barrier. However, knowledge of antigen processing and presentation upon dermal vaccination is sparse. In this study we determined antigen processing routes that lead to CD8(+) T cell

  17. Identification of protective antigens for vaccination against systemic salmonellosis

    Directory of Open Access Journals (Sweden)

    Dirk eBumann

    2014-08-01

    Full Text Available There is an urgent medical need for improved vaccines with broad serovar coverage and high efficacy against systemic salmonellosis. Subunit vaccines offer excellent safety profiles but require identification of protective antigens, which remains a challenging task. Here, I review crucial properties of Salmonella antigens that might help to narrow down the number of potential candidates from more than 4000 proteins encoded in Salmonella genomes, to a more manageable number of 50-200 most promising antigens. I also discuss complementary approaches for antigen identification and potential limitations of current pre-clinical vaccine testing.

  18. Overview of Plant-Made Vaccine Antigens against Malaria

    Directory of Open Access Journals (Sweden)

    Marina Clemente

    2012-01-01

    Full Text Available This paper is an overview of vaccine antigens against malaria produced in plants. Plant-based expression systems represent an interesting production platform due to their reduced manufacturing costs and high scalability. At present, different Plasmodium antigens and expression strategies have been optimized in plants. Furthermore, malaria antigens are one of the few examples of eukaryotic proteins with vaccine value expressed in plants, making plant-derived malaria antigens an interesting model to analyze. Up to now, malaria antigen expression in plants has allowed the complete synthesis of these vaccine antigens, which have been able to induce an active immune response in mice. Therefore, plant production platforms offer wonderful prospects for improving the access to malaria vaccines.

  19. A modern approach for epitope prediction: identification of foot-and-mouth disease virus peptides binding bovine leukocyte antigen (BoLA) class I molecules

    DEFF Research Database (Denmark)

    Pandya, Mital; Rasmussen, Michael; Hansen, Andreas

    2015-01-01

    Major histocompatibility complex (MHC) class I molecules regulate adaptive immune responses through the presentation of antigenic peptides to CD8+ T cells. Polymorphisms in the peptide binding region of class I molecules determine peptide binding affinity and stability during antigen presentation......, and different antigen peptide motifs are associated with specific genetic sequences of class I molecules. Understanding bovine leukocyte antigen (BoLA), peptide-MHC class I binding specificities may facilitate development of vaccines or reagents for quantifying the adaptive immune response to intracellular...... pathogens, such as foot-and-mouth disease virus (FMDV). Six synthetic BoLA class I (BoLA-I) molecules were produced, and the peptide binding motif was generated for five of the six molecules using a combined approach of positional scanning combinatorial peptide libraries (PSCPLs) and neural network...

  20. 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

  1. Tumor Associated Antigenic Peptides in Prostate Cancer

    National Research Council Canada - National Science Library

    Tiwari, Raj

    1999-01-01

    .... We proposed to identify these novel antigens in an experimental rat model using purified preparations of the heat shock protein gp96 and a library of synthetic distinct antibodies that were available...

  2. Phase 1 clinical study of cyclophilin B peptide vaccine for patients with lung cancer.

    Science.gov (United States)

    Gohara, Rumi; Imai, Nobue; Rikimaru, Toru; Yamada, Akira; Hida, Naoya; Ichiki, Masao; Kawamoto, Mayumi; Matsunaga, Kazuko; Ashihara, Junko; Yano, Sayoko; Tamura, Mayumi; Ohkouchi, Shinya; Yamana, Hideaki; Oizumi, Kotaro; Itoh, Kyogo

    2002-01-01

    Cyclophilin B (CypB) possesses two antigenic epitopes (CypB(84-92) and CypB(91-99) ) recognized by HLA-A24-restricted and tumor-specific cytotoxic T lymphocytes (CTLs). To determine the safety of CypB-derived peptides and its ability to generate antitumor immune responses, patients with advanced lung cancer received subcutaneous vaccinations of these peptides or their modified peptides. All 16 patients were vaccinated with CypB(91-99) or its modified peptide, whereas only two patients were vaccinated with the modified CypB(84-92), as immediate-type hypersensitivity to CypB(84-92) or its modified peptide was observed in the remaining patients. No severe adverse events were associated with the vaccination. No significant increase in cellular responses to either peptides or tumor cells was observed in the postvaccination PBMCs by the conventional CTL assays in any patients tested. These results suggest that the vaccination of CypB(91-99) peptide was safe, but failed to induce objective immune responses at this regimen.

  3. Dendrimer-conjugated peptide vaccine enhances clearance of Chlamydia trachomatis genital infection.

    Science.gov (United States)

    Ganda, Ingrid S; Zhong, Qian; Hali, Mirabela; Albuquerque, Ricardo L C; Padilha, Francine F; da Rocha, Sandro R P; Whittum-Hudson, Judith A

    2017-07-15

    Peptide-based vaccines have emerged in recent years as promising candidates in the prevention of infectious diseases. However, there are many challenges to maintaining in vivo peptide stability and enhancement of peptide immunogenicity to generate protective immunity which enhances clearance of infections. Here, a dendrimer-based carrier system is proposed for peptide-based vaccine delivery, and shows its anti-microbial feasibility in a mouse model of Chlamydia trachomatis. Chlamydiae are the most prevalent sexually transmitted bacteria worldwide, and also the causal agent of trachoma, the leading cause of preventable infectious blindness. In spite of the prevalence of this infectious agent and the many previous vaccine-related studies, there is no vaccine commercially available. The carrier system proposed consists of generation 4, hydroxyl-terminated, polyamidoamine (PAMAM) dendrimers (G4OH), to which a peptide mimic of a chlamydial glycolipid antigen-Peptide 4 (Pep4, AFPQFRSATLLL) was conjugated through an ester bond. The ester bond between G4OH and Pep4 is expected to break down mainly in the intracellular environment for antigen presentation. Pep4 conjugated to dendrimer induced Chlamydia-specific serum antibodies after subcutaneous immunizations. Further, this new vaccine formulation significantly protected immunized animals from vaginal challenge with infectious Chlamydia trachomatis, and it reduced infectious loads and tissue (genital tract) damage. Pep4 conjugated to G4OH or only mixed with peptide provided enhanced protection compared to Pep4 and adjuvant (i.e. alum), suggesting a potential adjuvant effect of the PAMAM dendrimer. Combined, these results demonstrate that hydroxyl-terminated PAMAM dendrimer is a promising polymeric nanocarrier platform for the delivery of peptide vaccines and this approach has potential to be expanded to other infectious intracellular bacteria and viruses of public health significance. Copyright © 2017 Elsevier B.V. All

  4. Analysis of Swine Leukocyte Antigen Peptide Binding Profiles and the Identification of T cell Epitopes by Tetramer Staining

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers

    class I peptide binding characteristics in relation to immune responses to vaccination or infection. Applying proven technologies to newly produced, recombinant swine leukocyte antigen (SLA) class I proteins yielded a body of data for peptide:SLA:β2m (pSLA) complex affinity and stability. Mapping...... system to specifically identify and react upon non-self peptide fragments unique only to the foreign intruder. The polymorphism of the MHC molecule effectively individualizes the immune response of each member of any given species. Moreover, responding T cells recognize antigen ligands, only...... in the context of peptide:MHC:β2m (pMHC) complex. The gene encoding the MHC is one of the most polymorphic regions of the genome known. Despite thousands of different human leukocyte antigen (HLA) variants identified, each member of a species only inherits and expresses a few of these MHC alleles. The “MHC...

  5. Idala: An unnamed Function Peptide Vaccine for Tuberculosis

    African Journals Online (AJOL)

    Color development in a microplate reader was ... peptide vaccine for tuberculosis tested by mice immunogenicity experiment. Keywords: ... potential new tuberculosis vaccine candidate. [3]. ..... New York and London: Garland Science,.

  6. Artificially synthesized helper/killer-hybrid epitope long peptide (H/K-HELP): preparation and immunological analysis of vaccine efficacy.

    Science.gov (United States)

    Masuko, Kazutaka; Wakita, Daiko; Togashi, Yuji; Kita, Toshiyuki; Kitamura, Hidemitsu; Nishimura, Takashi

    2015-01-01

    To elucidate the immunologic mechanisms of artificially synthesized helper/killer-hybrid epitope long peptide (H/K-HELP), which indicated a great vaccine efficacy in human cancers, we prepared ovalbumin (OVA)-H/K-HELP by conjugating killer and helper epitopes of OVA-model tumor antigen via a glycine-linker. Vaccination of C57BL/6 mice with OVA-H/K-HELP (30 amino acids) but not with short peptides mixture of class I-binding peptide (8 amino-acids) and class II-binding peptide (17 amino-acids) combined with adjuvant CpG-ODN (cytosine-phosphorothioate-guanine oligodeoxynucleotides), induced higher numbers of OVA-tetramer-positive CTL with concomitant activation of IFN-γ-producing CD4(+) Th1 cells. However, replacement of glycine-linker of OVA-H/K-HELP with other peptide-linker caused a significant decrease of vaccine efficacy of OVA-H/K-HELP. In combination with adjuvant CpG-ODN, OVA-H/KHELP exhibited greater vaccine efficacy compared with short peptides vaccine, in both preventive and therapeutic vaccine models against OVA-expressing EG-7 tumor. The elevated vaccine efficacy of OVAH/K-HELP might be derived from the following mechanisms: (i) selective presentation by only professional dendritic cells (DC) in vaccinated draining lymph node (dLN); (ii) a long-term sustained antigen presentation exerted by DC to stimulate both CTL and Th1 cells; (iii) formation of three cells interaction among DC, Th and CTL. In comparative study, H/K-HELP indicated stronger therapeutic vaccine efficacy compared with that of extended class I synthetic long peptide, indicating that both the length of peptide and the presence of Th epitope peptide were crucial aspects for preparing artificially synthesized H/K-HELP vaccine. Copyright © 2014 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  7. IMMUNOLOGICAL CHARACTERISTIC OF SYNTHETIC PEPTIDES SIMILAR TO ACTUAL HIV ANTIGEN DETERMINANTS

    Directory of Open Access Journals (Sweden)

    S. V. Korobova

    2016-01-01

    Full Text Available The development of HIV vaccine remains an important goal in prophylaxis and therapy of HIV/ AIDS epidemics. There are various approaches for development of а candidate vaccine based on induction of neutralizing antibodies and cell-mediated immunity. Synthetic peptides are considered promising vaccine antigens since they are capable of activating both humoral and cellular immune response. HIV-1 envelope gp120 is the target for neutralizing antiviral antibodies. The V3 region of the HIV-1 gp120 is highly immunogenic and important for the virus-coreceptor interaction. In a RV144 vaccine trial, the levels of vaccine-induced IgG antibodies recognizing V1V2 regions from multiple HIV-1 subtypes show inverse correlations with a risk for HIV-1 infection. Meanwhile, HIV is characterized by high diversity. The consensus and mosaic immunogens are complete but artificial proteins, which are computationally designed to elicit immune responses with improved cross-reactive broadness. We have been studied immunogenic properties of synthetic peptides derived from V1, V2, V3 loop regions of the consensus M HIV1 (CON-S sequence group of the gp 120 envelope protein and V3 loop derived from a Russian RUA022a2 isolate. These peptides specifically reacted to HIV-positive sera in ELISA, thus indicating their similarity to appropriate HIV proteins. The peptides proved to be weakly immunogenic. Therefore, Freund complete adjuvant was used to enhance peptide immunogenicity. To assess the immunogenicity, the mice were immunized with a peptide mixture. Antibodies have been developed to every peptide from the mixture, being, predominantly, of IgG isotype. The antibody titers depended on the length of peptide sequences. However, the sera from immunized mice did not have a HIV neutralizing activity. The serum neutralization was assessed by pseudovirus-based assay, using a molecular clone of virus isolates CAP 45.2.00.G3 and QH.209.14.M.EnvA2. The virus neutralization is a

  8. Chitosan-Poly (I:C-PADRE Based Nanoparticles as Delivery Vehicles for Synthetic Peptide Vaccines

    Directory of Open Access Journals (Sweden)

    Jorge F. Correia-Pinto

    2015-09-01

    Full Text Available The safety and precision of peptide antigens has prompted the search for adjuvants capable of increasing the immune response against these intrinsically poorly immunogenic antigens. The integration of both immunostimulants and peptide antigens within nanometric delivery systems for their co-delivery to immune cells is a promising vaccination strategy. With this in mind, the potential synergistic effect of the immunostimulant poly (I:C (pIC and a T-Helper peptide (PADRE, integrated into a chitosan (CS based nanostructure, was explored. The value of this nanostructured combination of materials was assessed for a peptide antigen (1338aa derived from the HPV-16 L2 protein. These nanoparticles, produced by ionic gelation technique, exhibited a nanometric size (<300 nm, a high positive surface charge (>40 mV and high pIC association efficiency (>96%. They also showed capacity for the association of both the 1338aa and PADRE peptides. The influence of the presence of pIC and PADRE in the nanocomposition, as well as that of the peptide presentation form (encapsulated versus surface adsorbed on the antibody induction was evaluated in a preliminary in vivo study. The data obtained highlights the possibility to engineer nanoparticles through the rational combination of a number of adjuvant molecules together with the antigen.

  9. First peptide vaccine providing protection against viral infection in the target animal: studies of canine parvovirus in dogs.

    OpenAIRE

    Langeveld, J P; Casal, J I; Osterhaus, A D; Cortés, E; de Swart, R; Vela, C; Dalsgaard, K; Puijk, W C; Schaaper, W M; Meloen, R H

    1994-01-01

    textabstractA synthetic peptide vaccine which protects dogs against challenge with virulent canine parvovirus is described. The amino acid sequence used was discovered in previous studies on the immunogenic properties of previously mapped antigenic sites and represents the amino-terminal region of viral protein VP2. As with marker vaccines, it is possible to discriminate between vaccinated dogs that have not been exposed to the virus and dogs that have been infected with the virus. The protec...

  10. Autologous peptides constitutively occupy the antigen binding site on Ia

    DEFF Research Database (Denmark)

    Buus, S; Sette, A; Colon, S M

    1988-01-01

    Low molecular weight material associated with affinity-purified class II major histocompatibility complex (MHC) molecules of mouse (Ia) had the expected properties of peptides bound to the antigen binding site of Ia. Thus, the low molecular weight material derived from the I-Ad isotype...

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

    International Nuclear Information System (INIS)

    Kim, Seung Jo; Suh, Dongchul; Park, Sang Eun; Park, Jeong-Sook; Byun, Hyang-Min; Lee, Chan; Lee, Sun Young; Kim, Inho; Oh, Yu-Kyoung

    2003-01-01

    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 IgG 2a rather than IgG 1 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

  12. Strategies to enhance immunogenicity of cDNA vaccine encoded antigens by modulation of antigen processing

    NARCIS (Netherlands)

    Platteel, Anouk C M; Marit de Groot, A; Andersen, Peter; Ovaa, Huib; Kloetzel, Peter M; Mishto, Michele; Sijts, Alice J A M

    2016-01-01

    Most vaccines are based on protective humoral responses while for intracellular pathogens CD8(+) T cells are regularly needed to provide protection. However, poor processing efficiency of antigens is often a limiting factor in CD8(+) T cell priming, hampering vaccine efficacy. The multistage cDNA

  13. Mapping the antigenic structure of porcine parvovirus at the level of peptides

    DEFF Research Database (Denmark)

    Kamstrup, Søren; Langeveld, Jan; Bøtner, Anette

    1998-01-01

    The antigenic structure of the capsid proteins of porcine parvovirus (PPV) was investigated. A total of nine linear epitopes were identified by Pepscan using porcine or rabbit anti-PPV antisera. No sites were identified with a panel of neutralising monoclonal antibodies (MAbs). All epitopes were...... located in the region corresponding to the major capsid protein VP2. Based on this information, and on analogy to other autonomous parvoviruses, 24 different peptides were synthesised, coupled to keyhole limpet haemocyanin (KLH) and used to immunise rabbits. Most antisera were able to bind viral protein....... It is concluded that in PPV, the VP2 N-terminus is involved in virus neutralisation (VN) and peptides from this region are therefore primary targets for developing peptide-based vaccines against this virus....

  14. 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

    Background: Computational methods for T cell-based vaccine target discovery focus on selection of highly conserved peptides identified across pathogen variants, followed by prediction of their binding of human leukocyte antigen molecules. However, experimental studies have shown that T cells ofte...... or proteome using human leukocyte antigen binding predictions and made a web-accessible software implementation freely available at http://met-hilab.cbs.dtu.dk/blockcons/....

  15. Peptide mimic for influenza vaccination using nonnatural combinatorial chemistry

    Science.gov (United States)

    Miles, John J.; Tan, Mai Ping; Dolton, Garry; Galloway, Sarah A.E.; Laugel, Bruno; Makinde, Julia; Matthews, Katherine K.; Watkins, Thomas S.; Wong, Yide; Clark, Richard J.; Pentier, Johanne M.; Attaf, Meriem; Lissina, Anya; Ager, Ann; Gallimore, Awen; Gras, Stephanie; Rossjohn, Jamie; Burrows, Scott R.; Cole, David K.; Price, David A.

    2018-01-01

    Polypeptide vaccines effectively activate human T cells but suffer from poor biological stability, which confines both transport logistics and in vivo therapeutic activity. Synthetic biology has the potential to address these limitations through the generation of highly stable antigenic “mimics” using subunits that do not exist in the natural world. We developed a platform based on D–amino acid combinatorial chemistry and used this platform to reverse engineer a fully artificial CD8+ T cell agonist that mirrored the immunogenicity profile of a native epitope blueprint from influenza virus. This nonnatural peptide was highly stable in human serum and gastric acid, reflecting an intrinsic resistance to physical and enzymatic degradation. In vitro, the synthetic agonist stimulated and expanded an archetypal repertoire of polyfunctional human influenza virus–specific CD8+ T cells. In vivo, specific responses were elicited in naive humanized mice by subcutaneous vaccination, conferring protection from subsequent lethal influenza challenge. Moreover, the synthetic agonist was immunogenic after oral administration. This proof-of-concept study highlights the power of synthetic biology to expand the horizons of vaccine design and therapeutic delivery. PMID:29528337

  16. New Data on Vaccine Antigen Deficient Bordetella pertussis Isolates

    Directory of Open Access Journals (Sweden)

    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.

  17. Immunological consequences of using three different clinical/laboratory techniques of emulsifying peptide-based vaccines in incomplete Freund's adjuvant

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    Kast W Martin

    2006-10-01

    Full Text Available Abstract Incomplete Freund's adjuvant (IFA serves as a carrier for water-in-oil emulsion (W/O vaccines. The stability of such emulsions greatly affects vaccine safety and efficacy since continued presence of antigen depots at lymphoid organs releasing low-level antigens is known to stimulate a potent immune response and high-level systemic release of antigens can lead to tolerance. W/O emulsions for the purpose of clinical and laboratory peptide-based vaccinations have been prepared using the techniques of syringe extrusion, vortex or high-speed homogenization. There is no consensus in the field over which technique would be best to use and no immunological data are available that compare the three techniques. In this study, we compared the immune responses induced by a peptide-based vaccine prepared using vortex, syringe-extrusion and homogenization. The vaccination led to tumor rejection by mice vaccinated with the peptide-based vaccine prepared using all three techniques. The immunological data from the in vivo cytotoxicity assay showed a trend for lower responses and a higher variability and greater range in the immune responses induced by a vaccine that was emulsified by the vortex or homogenizer techniques as compared to the syringe-extrusion technique. There were statistically significant lower numbers of IFNγ-secreting cells induced when the mice were vaccinated with a peptide-based vaccine emulsion prepared using the vortex compared to the syringe-extrusion technique. At a suboptimal vaccine dose, the mice vaccinated with a peptide-based vaccine emulsion prepared using the vortex technique had the largest tumors compared to the syringe-extrusion or the homogenizer technique. In the setting of a busy pharmacy that prepares peptide-based vaccine emulsions for clinical studies, the vortex technique can still be used but we urge investigators to take special care in their choice of mixing vessels for the vortex technique as that can

  18. A novel multi-antigen virally vectored vaccine against Mycobacterium avium subspecies paratuberculosis.

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    Tim J Bull

    Full Text Available BACKGROUND: Mycobacterium avium subspecies paratuberculosis causes systemic infection and chronic intestinal inflammation in many species including primates. Humans are exposed through milk and from sources of environmental contamination. Hitherto, the only vaccines available against Mycobacterium avium subspecies paratuberculosis have been limited to veterinary use and comprised attenuated or killed organisms. METHODS: We developed a vaccine comprising a fusion construct designated HAV, containing components of two secreted and two cell surface Mycobacterium avium subspecies paratuberculosis proteins. HAV was transformed into DNA, human Adenovirus 5 (Ad5 and Modified Vaccinia Ankara (MVA delivery vectors. Full length expression of the predicted 95 kDa fusion protein was confirmed. PRINCIPAL FINDINGS: Vaccination of naïve and Mycobacterium avium subspecies paratuberculosis infected C57BL/6 mice using DNA-prime/MVA-boost or Ad5-prime/MVA-boost protocols was highly immunogenic resulting in significant IFN-gamma ELISPOT responses by splenocytes against recombinant vaccine antigens and a range of HAV specific peptides. This included strong recognition of a T-cell epitope GFAEINPIA located near the C-terminus of the fusion protein. Antibody responses to recombinant vaccine antigens and HAV specific peptides but not GFAEINPIA, also occurred. No immune recognition of vaccine antigens occurred in any sham vaccinated Mycobacterium avium subspecies paratuberculosis infected mice. Vaccination using either protocol significantly attenuated pre-existing Mycobacterium avium subspecies paratuberculosis infection measured by qPCR in spleen and liver and the Ad5-prime/MVA-boost protocol also conferred some protection against subsequent challenge. No adverse effects of vaccination occurred in any of the mice. CONCLUSIONS/SIGNIFICANCE: A range of modern veterinary and clinical vaccines for the treatment and prevention of disease caused by Mycobacterium avium

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

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    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.

  20. A paradigm for peptide vaccine delivery using viral epitopes encapsulated in degradable polymer hydrogel capsules.

    Science.gov (United States)

    Chong, Siow-Feng; Sexton, Amy; De Rose, Robert; Kent, Stephen J; Zelikin, Alexander N; Caruso, Frank

    2009-10-01

    We report on the use of degradable polymer capsules as carriers for the delivery of oligopeptide antigens to professional antigen presenting cells (APCs). To achieve encapsulation, oligopeptide sequences were covalently linked to a negatively charged carrier polymer via biodegradable linkages and the resulting conjugate was then adsorbed onto amine-functionalized silica particles. These peptide-coated particles were then used as templates for the layer-by-layer (LbL) deposition of thiolated poly(methacrylic acid) (PMA(SH)) and poly(vinylpyrrolidone) (PVPON) multilayers. Removal of the silica core and disruption of the hydrogen bonding between PMA(SH) and PVPON by altering the solution pH yielded disulfide-stabilized PMA capsules that retain the encapsulated cargo in an oxidative environment. In the presence of a natural reducing agent, glutathione, cleavage of the disulfide bonds causes release of the peptide from the capsules. The developed strategy provides control over peptide loading into polymer capsules and yields colloidally stable micron- and submicron-sized carriers with uniform size and peptide loading. The conjugation and encapsulation procedures were proven to be non-degrading to the peptide vaccines. The peptide-loaded capsules were successfully used to deliver their cargo to APCs and activate CD8 T lymphocytes in a non-human primate model of SIV infection ex vivo. The reported approach represents a novel paradigm in the delivery of peptide vaccines and other therapeutic agents.

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

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    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.

  2. 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

    Background: Computational methods for T cell-based vaccine target discovery focus on selection of highly conserved peptides identified across pathogen variants, followed by prediction of their binding of human leukocyte antigen molecules. However, experimental studies have shown that T cells often...... target diverse regions in highly variable viral pathogens and this diversity may need to be addressed through redefinition of suitable peptide targets. Methods: We have developed a method for antigen assessment and target selection for polyvalent vaccines, with which we identified immune epitopes from...... 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...

  3. A novel strategy to improve antigen presentation for active immunotherapy in cancer. Fusion of the human papillomavirus type 16 E7 antigen to a cell penetrating peptide

    International Nuclear Information System (INIS)

    Granadillo, Milaid; Torrens, Isis; Guerra, Maribel

    2012-01-01

    Facilitating the delivery of exogenous antigens to antigen-presenting cells, ensuing processing and presentation via the major histocompatibility complex class I and induction of an effective immune response are fundamental for an effective therapeutic cancer vaccine. In this regard, we propose the use of cell-penetrating peptides fused to a tumor antigen. To demonstrate this concept we designed a fusion protein comprising a novel cell-penetrating and immunostimulatory peptide corresponding to residues 32 to 51 of the Limulus anti-lipopolysaccharide factor protein (LALF 32-51 ) linked to human papillomavirus 16 E7 antigen (LALF 32-51 -E7). In this work, we demonstrated that the immunization with LALF 32-51 -E7 using the TC-1 mouse model induces a potent and long-lasting anti-tumor response supported on an effective E7-specific CD8 +T -cell response. The finding that therapeutic immunization with LALF 32-51 or E7 alone, or an admixture of LALF32-51 and E7, does not induce significant tumor reduction indicates that covalent linkage between LALF 32-51 and E7 is required for the anti-tumor effect. These results support the use of this novel cell-penetrating peptide as an efficient means for delivering therapeutic targets into cellular compartments with the induction of a cytotoxic CD8 +T lymphocyte immune response. This approach is promissory for the treatment of tumors associated with the human papillomavirus 16, which is responsible for the 50% of cervical cancer cases worldwide and other malignancies. Furthermore, protein-based vaccines can circumvent the major histocompatibility complex specificity limitation associated with peptide vaccines providing a greater extent in their application

  4. Cancer vaccines: an update with special focus on ganglioside antigens.

    Science.gov (United States)

    Bitton, Roberto J; Guthmann, Marcel D; Gabri, Mariano R; Carnero, Ariel J L; Alonso, Daniel F; Fainboim, Leonardo; Gomez, Daniel E

    2002-01-01

    Vaccine development is one of the most promising and exciting fields in cancer research; numerous approaches are being studied to developed effective cancer vaccines. The aim of this form of therapy is to teach the patient's immune system to recognize the antigens expressed in tumor cells, but not in normal tissue, to be able to destroy these abnormal cells leaving the normal cells intact. In other words, is an attempt to teach the immune system to recognize antigens that escaped the immunologic surveillance and are by it, therefore able to survive and, in time, disseminate. However each research group developing a cancer vaccine, uses a different technology, targeting different antigens, combining different carriers and adjuvants, and using different immunization schedules. Most of the vaccines are still experimental and not approved by the US or European Regulatory Agencies. In this work, we will offer an update in the knowledge in cancer immunology and all the anticancer vaccine approaches, with special emphasis in ganglioside based vaccines. It has been demonstrated that quantitative and qualitative changes occur in ganglioside expression during the oncogenic transformation. Malignant transformation appears to activate enzymes associated with ganglioside glycosylation, resulting in altered patterns of ganglioside expression in tumors. Direct evidence of the importance of gangliosides as potential targets for active immunotherapy has been suggested by the observation that human monoclonal antibodies against these glycolipids induce shrinkage of human cutaneous melanoma metastasis. Thus, the cellular over-expression and shedding of gangliosides into the interstitial space may play a central role in cell growth regulation, immune tolerance and tumor-angiogenesis, therefore representing a new target for anticancer therapy. Since 1993 researchers at the University of Buenos Aires and the University of Quilmes (Argentina), have taken part in a project carried out by

  5. Limited antigenic variation in the Trypanosoma cruzi candidate vaccine antigen TSA-1.

    Science.gov (United States)

    Knight, J M; Zingales, B; Bottazzi, M E; Hotez, P; Zhan, B

    2014-12-01

    Chagas disease (American trypanosomiasis caused by Trypanosoma cruzi) is one of the most important neglected tropical diseases in the Western Hemisphere. The toxicities and limited efficacies of current antitrypanosomal drugs have prompted a search for alternative technologies such as a therapeutic vaccine comprised of T. cruzi antigens, including a recombinant antigen encoding the N-terminal 65 kDa portion of Trypomastigote surface antigen-1 (TSA-1). With at least six known genetically distinct T. cruzi lineages, variability between the different lineages poses a unique challenge for the development of broadly effective therapeutic vaccine. The variability across the major lineages in the current vaccine candidate antigen TSA-1 has not previously been addressed. To assess the variation in TSA-1, we cloned and sequenced TSA-1 from several different T. cruzi strains representing three of the most clinically relevant lineages. Analysis of the different alleles showed limited variation in TSA-1 across the different strains and fit with the current theory for the evolution of the different lineages. Additionally, minimal variation in known antigenic epitopes for the HLA-A 02 allele suggests that interlineage variation in TSA-1 would not impair the range and efficacy of a vaccine containing TSA-1. © 2014 John Wiley & Sons Ltd.

  6. Phase I vaccination trial of SYT-SSX junction peptide in patients with disseminated synovial sarcoma

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    Asanuma Hiroko

    2005-01-01

    Full Text Available Abstract Background Synovial sarcoma is a high-grade malignant tumor of soft tissue, characterized by the specific chromosomal translocation t(X;18, and its resultant SYT-SSX fusion gene. Despite intensive multimodality therapy, the majority of metastatic or relapsed diseases still remain incurable, thus suggesting a need for new therapeutic options. We previously demonstrated the antigenicity of SYT-SSX gene-derived peptides by in vitro analyses. The present study was designed to evaluate in vivo immunological property of a SYT-SSX junction peptide in selected patients with synovial sarcoma. Methods A 9-mer peptide (SYT-SSX B: GYDQIMPKK spanning the SYT-SSX fusion region was synthesized. Eligible patients were those (i who have histologically and genetically confirmed, unresectable synovial sarcoma (SYT-SSX1 or SYT-SSX2 positive, (ii HLA-A*2402 positive, (iii between 20 and 70 years old, (iv ECOG performance status between 0 and 3, and (v who gave informed consent. Vaccinations with SYT-SSX B peptide (0.1 mg or 1.0 mg were given subcutaneously six times at 14-day intervals. These patients were evaluated for DTH skin test, adverse events, tumor size, tetramer staining, and peptide-specific CTL induction. Results A total of 16 vaccinations were carried out in six patients. The results were (i no serious adverse effects or DTH reactions, (ii suppression of tumor progression in one patient, (iii increases in the frequency of peptide-specific CTLs in three patients and a decrease in one patient, and (iv successful induction of peptide-specific CTLs from four patients. Conclusions Our findings indicate the safety of the SYT-SSX junction peptide in the use of vaccination and also give support to the property of the peptide to evoke in vivo immunological responses. Modification of both the peptide itself and the related protocol is required to further improve the therapeutic efficacy.

  7. Peptides and Anti-peptide Antibodies for Small and Medium Scale Peptide and Anti-peptide Affinity Microarrays: Antigenic Peptide Selection, Immobilization, and Processing.

    Science.gov (United States)

    Zhang, Fan; Briones, Andrea; Soloviev, Mikhail

    2016-01-01

    This chapter describes the principles of selection of antigenic peptides for the development of anti-peptide antibodies for use in microarray-based multiplex affinity assays and also with mass-spectrometry detection. The methods described here are mostly applicable to small to medium scale arrays. Although the same principles of peptide selection would be suitable for larger scale arrays (with 100+ features) the actual informatics software and printing methods may well be different. Because of the sheer number of proteins/peptides to be processed and analyzed dedicated software capable of processing all the proteins and an enterprise level array robotics may be necessary for larger scale efforts. This report aims to provide practical advice to those who develop or use arrays with up to ~100 different peptide or protein features.

  8. Effect of vaccination on parvovirus antigen testing in kittens.

    Science.gov (United States)

    Patterson, Erin V; Reese, Michael J; Tucker, Sylvia J; Dubovi, Edward J; Crawford, P Cynda; Levy, Julie K

    2007-02-01

    To determine the frequency and duration of feline panleukopenia virus (FPV) vaccine-induced interference with fecal parvovirus diagnostic testing in cats. Prospective controlled study. Sixty-four 8- to 10-week-old specific-pathogen-free kittens. Kittens were inoculated once with 1 of 8 commercial multivalent vaccines containing modified-live virus (MLV) or inactivated FPV by the SC or intranasal routes. Feces were tested for parvovirus antigen immediately prior to vaccination, then daily for 14 days with 3 tests designed for detection of canine parvovirus. Serum anti-FPV antibody titers were determined by use of hemagglutination inhibition prior to vaccination and 14 days later. All fecal parvovirus test results were negative prior to vaccination. After vaccination, 1 kitten had positive test results with test 1, 4 kittens had positive results with test 2, and 13 kittens had positive results with test 3. Only 1 kitten had positive results with all 3 tests, and only 2 of those tests were subjectively considered to have strongly positive results. At 14 days after vaccination, 31% of kittens receiving inactivated vaccines had protective FPV titers, whereas 85% of kittens receiving MLV vaccines had protective titers. Animal shelter veterinarians should select fecal tests for parvovirus detection that have high sensitivity for FPV and low frequency of vaccine-related test interference. Positive parvovirus test results should be interpreted in light of clinical signs, vaccination history, and results of confirmatory testing. Despite the possibility of test interference, the benefit provided by universal MLV FPV vaccination of cats in high-risk environments such as shelters outweighs the impact on diagnostic test accuracy.

  9. First peptide vaccine providing protection against viral infection in the target animal: studies of canine parvovirus in dogs.

    NARCIS (Netherlands)

    J.P.M. Langeveld; J.I. Casal; A.D.M.E. Osterhaus (Albert); E. Cortes; R.L. de Swart (Rik); C. Vela (Carmen); K. Dalsgaard (Kristian); W.C. Puijk (Wouter); W.M.M. Schaaper (Wim); R.H. Meloen

    1994-01-01

    textabstractA synthetic peptide vaccine which protects dogs against challenge with virulent canine parvovirus is described. The amino acid sequence used was discovered in previous studies on the immunogenic properties of previously mapped antigenic sites and represents the amino-terminal region of

  10. Plant-made vaccine antigens and biopharmaceuticals.

    Science.gov (United States)

    Daniell, Henry; Singh, Nameirakpam D; Mason, Hugh; Streatfield, Stephen J

    2009-12-01

    Plant cells are ideal bioreactors for the production and oral delivery of vaccines and biopharmaceuticals, eliminating the need for expensive fermentation, purification, cold storage, transportation and sterile delivery. Plant-made vaccines have been developed for two decades but none has advanced beyond Phase I. However, two plant-made biopharmaceuticals are now advancing through Phase II and Phase III human clinical trials. In this review, we evaluate the advantages and disadvantages of different plant expression systems (stable nuclear and chloroplast or transient viral) and their current limitations or challenges. We provide suggestions for advancing this valuable concept for clinical applications and conclude that greater research emphasis is needed on large-scale production, purification, functional characterization, oral delivery and preclinical evaluation.

  11. Peptide dendrimers

    Czech Academy of Sciences Publication Activity Database

    Niederhafner, Petr; Šebestík, Jaroslav; Ježek, Jan

    2005-01-01

    Roč. 11, - (2005), 757-788 ISSN 1075-2617 R&D Projects: GA ČR(CZ) GA203/03/1362 Institutional research plan: CEZ:AV0Z40550506 Keywords : multiple antigen peptides * peptide dendrimers * synthetic vaccine * multipleantigenic peptides Subject RIV: CC - Organic Chemistry Impact factor: 1.803, year: 2005

  12. Structural characterization by NMR of a double phosphorylated chimeric peptide vaccine for treatment of Alzheimer's disease.

    Science.gov (United States)

    Ramírez-Gualito, Karla; Richter, Monique; Matzapetakis, Manolis; Singer, David; Berger, Stefan

    2013-04-26

    Rational design of peptide vaccines becomes important for the treatment of some diseases such as Alzheimer's disease (AD) and related disorders. In this study, as part of a larger effort to explore correlations of structure and activity, we attempt to characterize the doubly phosphorylated chimeric peptide vaccine targeting a hyperphosphorylated epitope of the Tau protein. The 28-mer linear chimeric peptide consists of the double phosphorylated B cell epitope Tau₂₂₉₋₂₃₇[pThr231/pSer235] and the immunomodulatory T cell epitope Ag85B₂₄₁₋₂₅₅ originating from the well-known antigen Ag85B of the Mycobacterium tuberculosis, linked by a four amino acid sequence -GPSL-. NMR chemical shift analysis of our construct demonstrated that the synthesized peptide is essentially unfolded with a tendency to form a β-turn due to the linker. In conclusion, the -GPSL- unit presumably connects the two parts of the vaccine without transferring any structural information from one part to the other. Therefore, the double phosphorylated epitope of the Tau peptide is flexible and accessible.

  13. Chagas disease-specific antigens: characterization of epitopes in CRA/FRA by synthetic peptide mapping and evaluation by ELISA-peptide assay.

    Science.gov (United States)

    Bottino, Carolina G; Gomes, Luciano P; Pereira, José B; Coura, José R; Provance, David William; De-Simone, Salvatore G

    2013-12-03

    The identification of epitopes in proteins recognized by medically relevant antibodies is useful for the development of peptide-based diagnostics and vaccines. In this study, epitopes in the cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) proteins from Trypanosoma cruzi were identified using synthetic peptide techniques and pooled sera from Chagasic patients. The epitopes were further assayed with an ELISA assay based on synthetic peptides. Twenty-two overlapping synthetic peptides representing the coding sequence of the T. cruzi CRA and FRA proteins were assessed by a Spot-synthesis array analysis using sera donated by patients with Chagas disease. Shorter peptides were selected that represented the determined epitopes and synthesized by solid phase synthesis to evaluate the patterns of cross-reactivities and discrimination through an ELISA-diagnostic assay. The peptide Spot-synthesis array successfully identified two IgG antigenic determinants in the CRA protein and four in FRA. Bioinformatics suggested that the CRA antigens were unique to T. cruzi while the FRA antigen showed similarity with sequences present within various proteins from Leishmania sp. Subsequently, shorter peptides representing the CRA-1, CRA-2 and FRA-1 epitopes were synthesized by solid phase synthesis and assayed by an ELISA-diagnostic assay. The CRA antigens gave a high discrimination between Chagasic, Leishmaniasis and T. cruzi-uninfected serum. A sensitivity and specificity of 100% was calculated for CRA. While the FRA antigen showed a slightly lower sensitivity (91.6%), its specificity was only 60%. The epitopes recognized by human anti-T. cruzi antibodies have been precisely located in two biomarkers of T. cruzi, CRA and FRA. The results from screening a panel of patient sera through an ELISA assay based on peptides representing these epitopes strongly suggest that the sequences from CRA would be useful for the development of diagnostic reagents that could

  14. 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. Copyright © 2013 Wiley Periodicals, Inc.

  15. Screening of random peptide library of hemagglutinin from pandemic 2009 A(H1N1 influenza virus reveals unexpected antigenically important regions.

    Directory of Open Access Journals (Sweden)

    Wanghui Xu

    Full Text Available The antigenic structure of the membrane protein hemagglutinin (HA from the 2009 A(H1N1 influenza virus was dissected with a high-throughput screening method using complex antisera. The approach involves generating yeast cell libraries displaying a pool of random peptides of controllable lengths on the cell surface, followed by one round of fluorescence-activated cell sorting (FACS against antisera from mouse, goat and human, respectively. The amino acid residue frequency appearing in the antigenic peptides at both the primary sequence and structural level was determined and used to identify "hot spots" or antigenically important regions. Unexpectedly, different antigenic structures were seen for different antisera. Moreover, five antigenic regions were identified, of which all but one are located in the conserved HA stem region that is responsible for membrane fusion. Our findings are corroborated by several recent studies on cross-neutralizing H1 subtype antibodies that recognize the HA stem region. The antigenic peptides identified may provide clues for creating peptide vaccines with better accessibility to memory B cells and better induction of cross-neutralizing antibodies than the whole HA protein. The scheme used in this study enables a direct mapping of the antigenic regions of viral proteins recognized by antisera, and may be useful for dissecting the antigenic structures of other viral proteins.

  16. Synthetic Long Peptide Influenza Vaccine Containing Conserved T and B Cell Epitopes Reduces Viral Load in Lungs of Mice and Ferrets.

    Directory of Open Access Journals (Sweden)

    S K Rosendahl Huber

    Full Text Available Currently licensed influenza vaccines mainly induce antibodies against highly variable epitopes. Due to antigenic drift, protection is subtype or strain-specific and regular vaccine updates are required. In case of antigenic shifts, which have caused several pandemics in the past, completely new vaccines need to be developed. We set out to develop a vaccine that provides protection against a broad range of influenza viruses. Therefore, highly conserved parts of the influenza A virus (IAV were selected of which we constructed antibody and T cell inducing peptide-based vaccines. The B epitope vaccine consists of the highly conserved HA2 fusion peptide and M2e peptide coupled to a CD4 helper epitope. The T epitope vaccine comprises 25 overlapping synthetic long peptides of 26-34 amino acids, thereby avoiding restriction for a certain MHC haplotype. These peptides are derived from nucleoprotein (NP, polymerase basic protein 1 (PB1 and matrix protein 1 (M1. C57BL/6 mice, BALB/c mice, and ferrets were vaccinated with the B epitopes, 25 SLP or a combination of both. Vaccine-specific antibodies were detected in sera of mice and ferrets and vaccine-specific cellular responses were measured in mice. Following challenge, both mice and ferrets showed a reduction of virus titers in the lungs in response to vaccination. Summarizing, a peptide-based vaccine directed against conserved parts of influenza virus containing B and T cell epitopes shows promising results for further development. Such a vaccine may reduce disease burden and virus transmission during pandemic outbreaks.

  17. Marked differences in human melanoma antigen-specific T cell responsiveness after vaccination using a functional microarray.

    Directory of Open Access Journals (Sweden)

    Daniel S Chen

    2005-10-01

    Full Text Available In contrast to many animal model studies, immunotherapeutic trials in humans suffering from cancer invariably result in a broad range of outcomes, from long-lasting remissions to no discernable effect.In order to study the T cell responses in patients undergoing a melanoma-associated peptide vaccine trial, we have developed a high-throughput method using arrays of peptide-major histocompatibility complexes (pMHC together with antibodies against secreted factors. T cells were specifically immobilized and activated by binding to particular pMHCs. The antibodies, spotted together with the pMHC, specifically capture cytokines secreted by the T cells. This technique allows rapid, simultaneous isolation and multiparametric functional characterization of antigen-specific T cells present in clinical samples. Analysis of CD8+ lymphocytes from ten melanoma patients after peptide vaccination revealed a diverse set of patient- and antigen-specific profiles of cytokine secretion, indicating surprising differences in their responsiveness. Four out of four patients who showed moderate or greater secretion of both interferon-gamma (IFNgamma and tumor necrosis factor-alpha (TNFalpha in response to a gp100 antigen remained free of melanoma recurrence, whereas only two of six patients who showed discordant secretion of IFNgamma and TNFalpha did so.Such multiparametric analysis of T cell antigen specificity and function provides a valuable tool with which to dissect the molecular underpinnings of immune responsiveness and how this information correlates with clinical outcome.

  18. Peptide vaccination against multiple myeloma using peptides derived from anti-apoptotic protein

    DEFF Research Database (Denmark)

    Jørgensen, Nicolai Grønne Dahlager; Ahmad, Shamaila Munir; Abildgaard, N.

    2016-01-01

    The B-cell lymphoma-2 (Bcl-2) family of proteins play a crucial role in multiple myeloma (MM), contributing to lacking apoptosis which is a hallmark of the disease. This makes the Bcl-2 proteins interesting targets for therapeutic peptide vaccination. We report a phase I trial of therapeutic vacc...... vaccination. Vaccination against Bcl-2 was well tolerated and was able to induce immune responses in patients with relapsed MM. © Stem Cell Investigation. All rights reserved.......The B-cell lymphoma-2 (Bcl-2) family of proteins play a crucial role in multiple myeloma (MM), contributing to lacking apoptosis which is a hallmark of the disease. This makes the Bcl-2 proteins interesting targets for therapeutic peptide vaccination. We report a phase I trial of therapeutic...... vaccination with peptides from the proteins Bcl-2, Bcl-XL and Mcl-1 in patients with relapsed MM. Vaccines were given concomitant with bortezomib. Out of 7 enrolled patients, 4 received the full course of 8 vaccinations. The remaining 3 patients received fewer vaccinations due to progression, clinical...

  19. Vaccination with lipid core peptides fails to induce epitope-specific T cell responses but confers non-specific protective immunity in a malaria model.

    Directory of Open Access Journals (Sweden)

    Simon H Apte

    Full Text Available Vaccines against many pathogens for which conventional approaches have failed remain an unmet public health priority. Synthetic peptide-based vaccines offer an attractive alternative to whole protein and whole organism vaccines, particularly for complex pathogens that cause chronic infection. Previously, we have reported a promising lipid core peptide (LCP vaccine delivery system that incorporates the antigen, carrier, and adjuvant in a single molecular entity. LCP vaccines have been used to deliver several peptide subunit-based vaccine candidates and induced high titre functional antibodies and protected against Group A streptococcus in mice. Herein, we have evaluated whether LCP constructs incorporating defined CD4(+ and/or CD8(+ T cell epitopes could induce epitope-specific T cell responses and protect against pathogen challenge in a rodent malaria model. We show that LCP vaccines failed to induce an expansion of antigen-specific CD8(+ T cells following primary immunization or by boosting. We further demonstrated that the LCP vaccines induced a non-specific type 2 polarized cytokine response, rather than an epitope-specific canonical CD8(+ T cell type 1 response. Cytotoxic responses of unknown specificity were also induced. These non-specific responses were able to protect against parasite challenge. These data demonstrate that vaccination with lipid core peptides fails to induce canonical epitope-specific T cell responses, at least in our rodent model, but can nonetheless confer non-specific protective immunity against Plasmodium parasite challenge.

  20. Detection of Avian Antigen-Specific T Cells Induced by Viral Vaccines

    DEFF Research Database (Denmark)

    Dalgaard, Tina Sørensen; Norup, Liselotte Rothmann; Juul-Madsen, Helle Risdahl

    2016-01-01

    Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen. There is ......Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen...

  1. Simulated digestion for testing the stability of edible vaccine based on Cucumber mosaic virus (CMV) chimeric particle display Hepatitis C virus (HCV) peptide.

    Science.gov (United States)

    Vitti, Antonella; Nuzzaci, Maria; Condelli, Valentina; Piazzolla, Pasquale

    2014-01-01

    Edible vaccines must survive digestive process and preserve the specific structure of the antigenic peptide to elicit effective immune response. The stability of a protein to digestive process can be predicted by subjecting it to the in vitro assay with simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Here, we describe the protocol of producing and using chimeric Cucumber mosaic virus (CMV) displaying Hepatitis C virus (HCV) derived peptide (R9) in double copy as an oral vaccine. Its stability after treatment with SGF and SIF and the preservation of the antigenic properties were verified by SDS-PAGE and immuno western blot techniques.

  2. Diversity of Francisella tularensis Schu4 antigens recognized by T lymphocytes after natural infections in humans: identification of candidate epitopes for inclusion in a rationally designed tularemia vaccine

    DEFF Research Database (Denmark)

    McMurry, Julie A; Gregory, Stephen H; Moise, Leonard

    2007-01-01

    The T lymphocyte antigens, which may have a role in protection against tularemia, were predicted by immunoinformatics analysis of Francisella tularensis Schu4. Twenty-seven class II putative promiscuous epitopes and 125 putative class I supertype epitopes were chosen for synthesis; peptides were...... responded to pools of 25 A2, A24, and B7 peptides, respectively. These data can aid in the development of novel epitope-based and subunit tularemia vaccines....

  3. Humoral and cellular immune responses to Yersinia pestis Pla antigen in humans immunized with live plague vaccine.

    Science.gov (United States)

    Feodorova, Valentina A; Lyapina, Anna M; Khizhnyakova, Maria A; Zaitsev, Sergey S; Sayapina, Lidiya V; Arseneva, Tatiana E; Trukhachev, Alexey L; Lebedeva, Svetlana A; Telepnev, Maxim V; Ulianova, Onega V; Lyapina, Elena P; Ulyanov, Sergey S; Motin, Vladimir L

    2018-06-01

    To establish correlates of human immunity to the live plague vaccine (LPV), we analyzed parameters of cellular and antibody response to the plasminogen activator Pla of Y. pestis. This outer membrane protease is an essential virulence factor that is steadily expressed by Y. pestis. PBMCs and sera were obtained from a cohort of naïve (n = 17) and LPV-vaccinated (n = 34) donors. Anti-Pla antibodies of different classes and IgG subclasses were determined by ELISA and immunoblotting. The analysis of antibody response was complicated with a strong reactivity of Pla with normal human sera. The linear Pla B-cell epitopes were mapped using a library of 15-mer overlapping peptides. Twelve peptides that reacted specifically with sera of vaccinated donors were found together with a major cross-reacting peptide IPNISPDSFTVAAST located at the N-terminus. PBMCs were stimulated with recombinant Pla followed by proliferative analysis and cytokine profiling. The T-cell recall response was pronounced in vaccinees less than a year post-immunization, and became Th17-polarized over time after many rounds of vaccination. The Pla protein can serve as a biomarker of successful vaccination with LPV. The diagnostic use of Pla will require elimination of cross-reactive parts of the antigen.

  4. Designing Peptide-Based HIV Vaccine for Chinese

    Science.gov (United States)

    Fan, Xiaojuan

    2014-01-01

    CD4+ T cells are central to the induction and maintenance of CD8+ T cell and antibody-producing B cell responses, and the latter are essential for the protection against disease in subjects with HIV infection. How to elicit HIV-specific CD4+ T cell responses in a given population using vaccines is one of the major areas of current HIV vaccine research. To design vaccine that targets specifically Chinese, we assembled a database that is comprised of sequences from 821 Chinese HIV isolates and 46 human leukocyte antigen (HLA) DR alleles identified in Chinese population. We then predicted 20 potential HIV epitopes using bioinformatics approaches. The combination of these 20 epitopes has a theoretical coverage of 98.1% of the population for both the prevalent HIV genotypes and also Chinese HLA-DR types. We suggest that testing this vaccine experimentally will facilitate the development of a CD4+ T cell vaccine especially catered for Chinese. PMID:25136573

  5. Identification of a peptide binding protein that plays a role in antigen presentation

    International Nuclear Information System (INIS)

    Lakey, E.K.; Margoliash, E.; Pierce, S.K.

    1987-01-01

    The helper T-cell response to globular proteins appears, in general, to require intracellular processing of the antigen, such that a peptide fragment containing the T-cell antigenic determinant is released and transported to and held on the surface of an Ia-expressing, antigen-presenting cell. However, the molecular details underlying these phenomena are largely unknown. The means by which antigenic peptides are anchored on the antigen-presenting cell surface was investigated. A cell surface protein is identified that was isolated by it ability to bind to a 24-amino acid peptide fragment of pigeon cytochrome c, residues 81-104, containing the major antigenic determinant for B10.A mouse T cells. This peptide binding protein, purified from [ 35 S]methionine-labeled cells, appears as two discrete bands of ≅72 and 74 kDa after NaDodSO 4 /PAGE. The protein can be eluted from the peptide affinity column with equivalent concentrations of either the antigenic pigeon cytochrome c peptide or the corresponding nonantigenic peptide of mouse cytochrome c. However, it does not bind to the native cytochromes c, either of pigeon or mouse, and thus the protein appears to recognize some structure available only in the free peptides. This protein plays a role in antigen presentation. Its expression is not major histocompatibility complex-restricted in that the blocking activity of the antisera can be absorbed on spleen cells from mice of different haplotypes. This peptide binding protein can be isolated from a variety of cell types, including B cells, T cells, and fibroblasts. The anchoring of processed peptides on the cell surface by such a protein may play a role in antigen presentation

  6. The simultaneous ex vivo detection of low-frequency antigen-specific CD4+ and CD8+ T-cell responses using overlapping peptide pools.

    Science.gov (United States)

    Singh, Satwinder Kaur; Meyering, Maaike; Ramwadhdoebe, Tamara H; Stynenbosch, Linda F M; Redeker, Anke; Kuppen, Peter J K; Melief, Cornelis J M; Welters, Marij J P; van der Burg, Sjoerd H

    2012-11-01

    The ability to measure antigen-specific T cells at the single-cell level by intracellular cytokine staining (ICS) is a promising immunomonitoring tool and is extensively applied in the evaluation of immunotherapy of cancer. The protocols used to detect antigen-specific CD8+ T-cell responses generally work for the detection of antigen-specific T cells in samples that have undergone at least one round of in vitro pre-stimulation. Application of a common protocol but now using long peptides as antigens was not suitable to simultaneously detect antigen-specific CD8+ and CD4+ T cells directly ex vivo in cryopreserved samples. CD8 T-cell reactivity to monocytes pulsed with long peptides as antigens ranged between 5 and 25 % of that observed against monocytes pulsed with a direct HLA class I fitting minimal CTL peptide epitope. Therefore, we adapted our ICS protocol and show that the use of tenfold higher concentration of long peptides to load APC, the use of IFN-α and poly(I:C) to promote antigen processing and improve T-cell stimulation, does allow for the ex vivo detection of low-frequency antigen-specific CD8+ and CD4+ T cells in an HLA-independent setting. While most of the improvements were related to increasing the ability to measure CD8+ T-cell reactivity following stimulation with long peptides to at least 50 % of the response detected when using a minimal peptide epitope, the final analysis of blood samples from vaccinated patients successfully showed that the adapted ICS protocol also increases the ability to ex vivo detect low-frequency p53-specific CD4+ T-cell responses in cryopreserved PBMC samples.

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

    Science.gov (United States)

    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 antibiotic free selectable markers or the ability to excise selectable marker genes. Hyperexpression of several therapeutic proteins, including human serum albumin (11.1% TSP), somatotropin (7% TSP), interferon-alpha (19% TSP), interferon-gamma (6% TSP), and antimicrobial peptide (21.5% TSP), facilitates efficient and economic purification. Also, the presence of chaperones and enzymes in chloroplasts facilitates assembly of complex multisubunit proteins and correct folding of human blood proteins with proper disulfide bonds. Functionality of chloroplast-derived vaccine antigens and therapeutic proteins has been demonstrated by several assays, including the macrophage lysis assay, GM1-ganglioside binding assay, protection of HeLA cells or human lung carcinoma cells against encephalomyocarditis virus, systemic immune response, protection against pathogen challenge, and growth or inhibition of cell cultures. Purification of human proinsulin has been achieved using novel purification strategies (inverse temperature transition property) that do not require expensive column chromatography techniques. Thus, transgenic chloroplasts are ideal bioreactors for production of functional human and animal therapeutic proteins in an environmentally friendly manner. PMID:19401820

  8. 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

  9. Development of a multi-epitope peptide vaccine inducing robust T cell responses against brucellosis using immunoinformatics based approaches.

    Science.gov (United States)

    Saadi, Mahdiye; Karkhah, Ahmad; Nouri, Hamid Reza

    2017-07-01

    Current investigations have demonstrated that a multi-epitope peptide vaccine targeting multiple antigens could be considered as an ideal approach for prevention and treatment of brucellosis. According to the latest findings, the most effective immunogenic antigens of brucella to induce immune responses are included Omp31, BP26, BLS, DnaK and L7-L12. Therefore, in the present study, an in silico approach was used to design a novel multi-epitope vaccine to elicit a desirable immune response against brucellosis. First, five novel T-cell epitopes were selected from Omp31, BP26, BLS, DnaK and L7-L12 proteins using different servers. In addition, helper epitopes selected from Tetanus toxin fragment C (TTFrC) were applied to induce CD4+ helper T lymphocytes (HTLs) responses. Selected epitopes were fused together by GPGPG linkers to facilitate the immune processing and epitope presentation. Moreover, cholera toxin B (CTB) was linked to N terminal of vaccine construct as an adjuvant by using EAAAK linker. A multi-epitope vaccine was designed based on predicted epitopes which was 377 amino acid residues in length. Then, the physico-chemical properties, secondary and tertiary structures, stability, intrinsic protein disorder, solubility and allergenicity of this multi-epitope vaccine were assessed using immunoinformatics tools and servers. Based on obtained results, a soluble, and non-allergic protein with 40.59kDa molecular weight was constructed. Expasy ProtParam classified this chimeric protein as a stable protein and also 89.8% residues of constructed vaccine were located in favored regions of the Ramachandran plot. Furthermore, this multi-epitope peptide vaccine was able to strongly induce T cell and B-cell mediated immune responses. In conclusion, immunoinformatics analysis indicated that this multi-epitope peptide vaccine can be effectively expressed and potentially be used for prophylactic or therapeutic usages against brucellosis. Copyright © 2017 Elsevier B.V. All

  10. Booster Vaccination: The Role of Reduced Antigen Content Vaccines as a Preschool Booster

    Directory of Open Access Journals (Sweden)

    Giovanni Gabutti

    2014-01-01

    Full Text Available The need for boosters for tetanus, diphtheria, pertussis, and polio, starting from preschool age, is related to the waning immune protection conferred by vaccination, the elimination/reduction of natural boosters due to large-scale immunization programs, and the possibility of reintroduction of wild agents from endemic areas. Taking into account the relevance of safety/tolerability in the compliance with vaccination among the population, it have been assessed whether today enough scientific evidences are available to support the use of dTap-IPV booster in preschool age. The review of the literature was conducted using the PubMed search engine. A total of 41 works has been selected; besides, the documentation produced by the World Health Organization, the European Centre for Disease Control, and the Italian Ministry of Health has been consulted. Many recent papers confirm the opportunity to use a low antigenic dose vaccine starting from 4 to 6 years of age. There is also evidence that 10 years after immunization the rate of seroprotected subjects against diphtheria does not differ significantly between those vaccinated with paediatric dose (DTaP or reduced dose (dTaP or dTap product. The dTpa vaccine is highly immunogenic for diphtheria toxoids regardless of prior vaccination history (2 + 1 and 3 + 1 schedules.

  11. Therapy of established B16-F10 melanoma tumors by a single vaccination of CTL/T helper peptides in VacciMax®

    Directory of Open Access Journals (Sweden)

    Korets-Smith Ella

    2007-04-01

    Full Text Available Abstract Background Melanoma tumors are known to express antigens that usually induce weak immune responses of short duration. Expression of both tumor-associated antigens p53 and TRP2 by melanoma cells raises the possibility of simultaneously targeting more than one antigen in a therapeutic vaccine. In this report, we show that VacciMax® (VM, a novel liposome-based vaccine delivery platform, can increase the immunogenicity of melanoma associated antigens, resulting in tumor elimination. Methods C57BL/6 mice bearing B16-F10 melanoma tumors were vaccinated subcutaneously 6 days post tumor implantation with a mixture of synthetic peptides (modified p53: 232–240, TRP-2: 181–188 and PADRE and CpG. Tumor growth was monitored and antigen-specific splenocyte responses were assayed by ELISPOT. Results Vaccine formulated in VM increased the number of both TRP2- and p53-specific IFN-γ producing splenocytes following a single vaccination. Vaccine formulated without VM resulted only in enhanced IFN-γ producing splenocytes to one CTL epitopes (TRP2:180–188, suggesting that VM overcomes antigen dominance and enhances immunogenicity of multiple epitopes. Vaccination of mice bearing 6-day old B16-F10 tumors with both TRP2 and p53-peptides formulated in VM successfully eradicated tumors in all mice. A control vaccine which contained all ingredients except liposomes resulted in eradication of tumors in no more than 20% of mice. Conclusion A single administration of VM is capable of inducing an effective CTL response to multiple tumor-associated antigens. The responses generated were able to reject 6-day old B16-F10 tumors.

  12. 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

    is generally known about how antigens and adjuvants interact at the molecular level. The aim of this study was to elucidate the mechanisms of interactions between the equally sized, but oppositely charged model protein antigens α-lactalbumin and lysozyme, and i) the clinically tested cationic liposomal...... 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 immunogenicity......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...

  13. An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Munang'andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

    2016-12-13

    Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia ( Niloticus oreochromis ) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy.

  14. An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus)

    Science.gov (United States)

    Munang’andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

    2016-01-01

    Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia (Niloticus oreochromis) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy. PMID:27983591

  15. Novel multi-peptide vaccination in Hla-A2+ hormone sensitive patients with biochemical relapse of prostate cancer.

    Science.gov (United States)

    Feyerabend, Susan; Stevanovic, Stefan; Gouttefangeas, Cécile; Wernet, Dorothee; Hennenlotter, Jörg; Bedke, Jens; Dietz, Klaus; Pascolo, Steve; Kuczyk, Markus; Rammensee, Hans-Georg; Stenzl, Arnulf

    2009-06-15

    A phase I/II trial was conducted to assess feasibility and tolerability of tumor associated antigen peptide vaccination in hormone sensitive prostate carcinoma (PC) patients with biochemical recurrence after primary surgical treatment. Nineteen HLA-A2 positive patients with rising PSA without detectable metastatic disease or local recurrence received 11 HLA-A*0201-restricted and two HLA class II synthetic peptides derived from PC tumor antigens subcutaneously for 18 months or until PSA progression. The vaccine was emulgated in montanide ISA51 and combined with imiquimod, GM-CSF, mucin-1-mRNA/protamine complex, local hyperthermia or no adjuvant. PSA was assessed, geometric mean doubling times (DT) calculated and clinical performance monitored. PSA DT of 4 out of 19 patients (21%) increased from 4.9 to 25.8 months during vaccination. Out of these, two patients (11%) exhibited PSA stability for 28 and 31 months which were still continuing at data cut-off. One patient showed no change of PSA DT during vaccination but decline after the therapy. Three patients had an interim PSA decline or DT increase followed by DT decrease compared to baseline PSA DT. Three of the responding patients received imiquimod and one the mucin-1-mRNA/protamine complex as adjuvant; both are Toll-like receptor-7 agonists. Eleven (58%) patients had progressive PSA values. The vaccine was well tolerated, and no grade III or IV toxicity occurred. Multi-peptide vaccination stabilized or slowed down PSA progress in four of 19 cases. The vaccination approach is promising with moderate adverse events. Long-term stability delayed androgen deprivation up to 31 months. TLR-7 co-activation seems to be beneficial.

  16. Entrapment of H1N1 Influenza Virus Derived Conserved Peptides in PLGA Nanoparticles Enhances T Cell Response and Vaccine Efficacy in Pigs.

    Science.gov (United States)

    Hiremath, Jagadish; Kang, Kyung-il; Xia, Ming; Elaish, Mohamed; Binjawadagi, Basavaraj; Ouyang, Kang; Dhakal, Santosh; Arcos, Jesus; Torrelles, Jordi B; Jiang, X; Lee, Chang Won; Renukaradhya, Gourapura J

    2016-01-01

    Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV). Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA) nanoparticle (PLGA-NP) based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2) chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant) significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs.

  17. Entrapment of H1N1 Influenza Virus Derived Conserved Peptides in PLGA Nanoparticles Enhances T Cell Response and Vaccine Efficacy in Pigs.

    Directory of Open Access Journals (Sweden)

    Jagadish Hiremath

    Full Text Available Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV. Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA nanoparticle (PLGA-NP based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2 chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs.

  18. Peptide amphiphile nanoparticles enhance the immune response against a CpG-adjuvanted influenza antigen

    NARCIS (Netherlands)

    Zope, H.; Quer, C.B.; Bomans, P.H.H.; Sommerdijk, N.A.J.M.; Kros, A.; Jiskoot, W.

    2014-01-01

    Cationic peptide amphiphile nanoparticles are employed for co-delivery of immune modulator CpG and antigen. This results in better targeting to the antigen presenting cells and eliciting strong Th1 response, which is effective against the intracellular pathogens.

  19. Functional mimicry of a discontinuous antigenic site by a designed synthetic peptide

    NARCIS (Netherlands)

    Villen, J.; Borras, E.; Schaaper, W.M.M.; Meloen, R.H.; Davila, M.; Domingo, E.; Giralt, E.; Andreu, D.

    2002-01-01

    Functional reproduction of the discontinuous antigenic site D of foot-and-mouth disease virus (FMDV) has been achieved by means of synthetic peptide constructions that integrate each of the three protein loops that define the antigenic site into a single molecule. The site D mimics were designed on

  20. 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

  1. Efficacy demonstration of tetanus vaccines by double antigen ELISA.

    Science.gov (United States)

    Rosskopf, U; Noeske, K; Werner, E

    2005-09-01

    This paper describes a double antigen ELISA (DAE) for rapid, specific and reliable assessment of the antitetanus immune status of horses and sheep. Compared with the indirect ELISA, the double antigen ELISA has the advantage of species-independent testing of sera. Thanks to its test design, it is more specific since the detected antibodies are forced to bind tetanus toxoid twice. In addition, it is very sensitive to tetanus antibodies, enabling the detection of low antibody titres, in range which is relevant for the assessment of the protective status (tetanus toxin neutralising antibodies). The detection limit of the DAE for tetanus antibodies is in the order of 10(-4) EU/ml. A comparison of in vitro results of individual sera with in vivo titres showed that horse sera with titres of 0.04 and 0.05 EU/ml in the DAE showed titres of > 0.05 IU and 0.034 IU/ml respectively during in vivo testing thus indicating good agreement. For tested sheep sera which were rated > 0.05 IU/ml in vivo, the corresponding titre in the DAE was 0.24 EU/ml. Clear tetanus antitoxin establishment of protective ELISA limits requires further comparative examination of sera with low titres (tetanus vaccines ad us. vet. As a consequence, the toxin neutralisation test (still being the standard method of choice for quantifying tetanus toxin neutralising antitoxin titres) could be replaced, since it requires too great a number of animals per test and involves considerable suffering for the animals. The test described here reduces the use of mice and guinea pigs within vaccine efficacy testing. In addition, it involves less exposure of the laboratory personnel to toxin.

  2. Structural requirements for the interaction between class II MHC molecules and peptide antigens

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Appella, E

    1990-01-01

    of binding, it is possible to define certain structural features of peptides that are associated with the capacity to bind to a particular MHC specificity (IA(d) or IE(d)); 3) IA(d) and IE(d) molecules recognize different and independent structures on the antigen molecule; 4) only about 10% of the single...... IA(d) and IE(d) molecules and their peptide ligands, we found that some structural characteristics apply to both antigen-MHC interactions. In particular, we found: 1) each MHC molecule is capable of binding many unrelated peptides through the same peptide-binding site; 2) despite this permissiveness...... amino acid substitutions tested on two IA(d)- and IE(d)-binding peptides had significant effect on their MHC-binding capacities, while over 80% of these substitutions significantly impaired T cell recognition of the Ia-peptide complex; 5) based on the segregation between residues that are crucial for T...

  3. Prime-boost BCG vaccination with DNA vaccines based in β-defensin-2 and mycobacterial antigens ESAT6 or Ag85B improve protection in a tuberculosis experimental model.

    Science.gov (United States)

    Cervantes-Villagrana, Alberto R; Hernández-Pando, Rogelio; Biragyn, Arya; Castañeda-Delgado, Julio; Bodogai, Monica; Martínez-Fierro, Margarita; Sada, Eduardo; Trujillo, Valentin; Enciso-Moreno, Antonio; Rivas-Santiago, Bruno

    2013-01-11

    The World Health Organization (WHO) has estimated that there are about 8 million new cases annually of active Tuberculosis (TB). Despite its irregular effectiveness (0-89%), the Bacillus Calmette-Guérin) BCG is the only vaccine available worldwide for prevention of TB; thus, the design is important of novel and more efficient vaccination strategies. Considering that β-defensin-2 is an antimicrobial peptide that induces dendritic cell maturation through the TLR-4 receptor and that both ESAT-6 and Ag85B are immunodominant mycobacterial antigens and efficient activators of the protective immune response, we constructed two DNA vaccines by the fusion of the gene encoding β-defensin-2 and antigens ESAT6 (pDE) and 85B (pDA). After confirming efficient local antigen expression that induced high and stable Interferon gamma (IFN-γ) production in intramuscular (i.m.) vaccinated Balb/c mice, groups of mice were vaccinated with DNA vaccines in a prime-boost regimen with BCG and with BCG alone, and 2 months later were challenged with the mild virulence reference strain H37Rv and the highly virulent clinical isolate LAM 5186. The level of protection was evaluated by survival, lung bacilli burdens, and extension of tissue damage (pneumonia). Vaccination with both DNA vaccines showed similar protection to that of BCG. After the challenge with the highly virulent Mycobacterium tuberculosis strain, animals that were prime-boosted with BCG and then boosted with both DNA vaccines showed significant higher survival and less tissue damage than mice vaccinated only with BCG. These results suggest that improvement of BCG vaccination, such as the prime-boost DNA vaccine, represents a more efficient vaccination scheme against TB. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. FULL-LENGTH PEPTIDE ASSAY OF ANTIGENIC PROFILE OF ENVELOPE PROTEINS FROM SIBERIAN ISOLATES OF HEPATITIS C VIRUS

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    A. A. Grazhdantseva

    2010-01-01

    Full Text Available Antigenic profiles of envelope glycoproteins of hepatitis C virus presented by three genotypes 1b, 2a/2c and 3a, which are most widespread in the territory of Russia and, in particular, in Novosibirsk, were studied using a panel of overlapping synthetic peptides. It was shown that highly immunogenic peptide epitopes of Е1 and Е2 proteins common for all HCV genotypes, are located in amino acid positions 250-260, 315-325 (Е1 protein, 390-400 (hypervariable region 1, 430-440, and 680-690 (Е2 protein. The greatest inter-genotypic differences were recorded in positions 280-290, 410-430 and 520-540. A novel antigenic determinant was detected in the region of aa 280-290 of the Е1 protein which was typical only for HCV 2a/2c genotype. A broad variation in the boundaries for the most epitopes suggests a high variability of the Е1 and Е2 viral proteins; however, a similar repertoire of antibodies induced by different HCV genotypes indicates to an opportunity of designing a new generation of cross-reactive HCV vaccines based on mapping of the E1 and E2 antigenic regions.

  5. Structural Characterization by NMR of a Double Phosphorylated Chimeric Peptide Vaccine for Treatment of Alzheimer’s Disease

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    Stefan Berger

    2013-04-01

    Full Text Available Rational design of peptide vaccines becomes important for the treatment of some diseases such as Alzheimer’s disease (AD and related disorders. In this study, as part of a larger effort to explore correlations of structure and activity, we attempt to characterize the doubly phosphorylated chimeric peptide vaccine targeting a hyperphosphorylated epitope of the Tau protein. The 28-mer linear chimeric peptide consists of the double phosphorylated B cell epitope Tau229-237[pThr231/pSer235] and the immunomodulatory T cell epitope Ag85B241-255 originating from the well-known antigen Ag85B of the Mycobacterium tuberculosis, linked by a four amino acid sequence -GPSL-. NMR chemical shift analysis of our construct demonstrated that the synthesized peptide is essentially unfolded with a tendency to form a β-turn due to the linker. In conclusion, the -GPSL- unit presumably connects the two parts of the vaccine without transferring any structural information from one part to the other. Therefore, the double phosphorylated epitope of the Tau peptide is flexible and accessible.

  6. High Antigen Dose Is Detrimental to Post-Exposure Vaccine Protection against Tuberculosis.

    Science.gov (United States)

    Billeskov, Rolf; Lindenstrøm, Thomas; Woodworth, Joshua; Vilaplana, Cristina; Cardona, Pere-Joan; Cassidy, Joseph P; Mortensen, Rasmus; Agger, Else Marie; Andersen, Peter

    2017-01-01

    Mycobacterium tuberculosis (Mtb), the etiologic agent of tuberculosis (TB), causes 1.8M deaths annually. The current vaccine, BCG, has failed to eradicate TB leaving 25% of the world's population with latent Mtb infection (LTBI), and 5-10% of these people will reactivate and develop active TB. An efficient therapeutic vaccine targeting LTBI could have an enormous impact on global TB incidence, and could be an important aid in fighting multidrug resistance, which is increasing globally. Here we show in a mouse model using the H56 (Ag85B-ESAT-6-Rv2660) TB vaccine candidate that post-exposure, but not preventive, vaccine protection requires low vaccine antigen doses for optimal protection. Loss of protection from high dose post-exposure vaccination was not associated with a loss of overall vaccine response magnitude, but rather with greater differentiation and lower functional avidity of vaccine-specific CD4 T cells. High vaccine antigen dose also led to a decreased ability of vaccine-specific CD4 T cells to home into the Mtb-infected lung parenchyma, a recently discovered important feature of T cell protection in mice. These results underscore the importance of T cell quality rather than magnitude in TB-vaccine protection, and the significant role that antigen dosing plays in vaccine-mediated protection.

  7. High Antigen Dose Is Detrimental to Post-Exposure Vaccine Protection against Tuberculosis

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    Rolf Billeskov

    2018-01-01

    Full Text Available Mycobacterium tuberculosis (Mtb, the etiologic agent of tuberculosis (TB, causes 1.8M deaths annually. The current vaccine, BCG, has failed to eradicate TB leaving 25% of the world’s population with latent Mtb infection (LTBI, and 5–10% of these people will reactivate and develop active TB. An efficient therapeutic vaccine targeting LTBI could have an enormous impact on global TB incidence, and could be an important aid in fighting multidrug resistance, which is increasing globally. Here we show in a mouse model using the H56 (Ag85B-ESAT-6-Rv2660 TB vaccine candidate that post-exposure, but not preventive, vaccine protection requires low vaccine antigen doses for optimal protection. Loss of protection from high dose post-exposure vaccination was not associated with a loss of overall vaccine response magnitude, but rather with greater differentiation and lower functional avidity of vaccine-specific CD4 T cells. High vaccine antigen dose also led to a decreased ability of vaccine-specific CD4 T cells to home into the Mtb-infected lung parenchyma, a recently discovered important feature of T cell protection in mice. These results underscore the importance of T cell quality rather than magnitude in TB-vaccine protection, and the significant role that antigen dosing plays in vaccine-mediated protection.

  8. Vaccination with map specific peptides reduces map burden in tissues of infected goats

    DEFF Research Database (Denmark)

    Melvang, Heidi Mikkelsen; Hassan, Sufia Butt; Thakur, Aneesh

    As an alternative to protein-based vaccines, we investigated the effect of post-exposure vaccination with Map specific peptides in a goat model aiming at developing a Map vaccine that will neither interfere with diagnosis of paratuberculosis nor bovine tuberculosis. Peptides were initially select...... in the unvaccinated control group seroconverted in ID Screen® ELISA at last sampling prior to euthanasia. These results indicate that a subunit vaccine against Map can induce a protective immune response against paratuberculosis in goats....

  9. Antigen uptake and expression of antigen presentation-related immune genes in flounder (Paralichthys olivaceus) after vaccination with an inactivated Edwardsiella tarda immersion vaccine, following hyperosmotic treatment.

    Science.gov (United States)

    Gao, Yingli; Tang, Xiaoqian; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

    2016-08-01

    Antigen uptake is a critical process for activation of the immune system, and therefore the ability to enhance antigen uptake is a primary consideration in the development of an immersion vaccination of fish. In the present work, flounders (Paralichthys olivaceus) were immersed in three hyperosmotic solutions with 40, 50 and 60‰ salinities, then transferred into seawater of normal salinity (i.e. 30‰) containing formalin-inactivated Edwardsiella tarda for 30 min. The antigen uptake in vaccinated flounder was determined using an absolute quantitative PCR (qPCR). The results showed significantly higher antigen uptake in the tissues of flounders immersed in solutions with 50‰ and 60‰ salinity compared to the control group directly immersed in vaccine (DI) (P immersed in the 50‰ salinity solution, whereas there was no significant difference in antigen uptake between the 40‰ salinity group and the DI group (P > 0.05). A rapid and significant increase in antigen uptake was detected in the mucosal-associated tissues including the gill, skin and intestine (P immersion, which was significantly higher than the levels of uptake measured in the other tissues (P immersion (hpi). The expression profiles of four antigen presentation-related immune genes (MHC Iα, MHC IIα, CD4-1 and CD8α) were investigated after immersion. These four genes showed a significantly stronger response in the immersed flounders exposed to 50‰ salinity compared with the DI group (P immersion, notably 50‰ salinity significantly enhanced antigen uptake and the expression of selected genes associated with antigen presentation, providing evidence for an enhanced immune activation of the fish's immune response by the hyperosmotic immersion treatment prior to vaccination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. A recombinant multi-antigen vaccine formulation containing Babesia bovis merozoite surface antigens MSA-2a1, MSA-2b and MSA-2c elicits invasion-inhibitory antibodies and IFN-γ producing cells

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    Alba Marina Gimenez

    2016-11-01

    Full Text Available Abstract Background Babesia bovis is a tick-transmitted protozoan hemoparasite and the causative agent of bovine babesiosis, a potential risk to more than 500 million cattle worldwide. The vaccines currently available are based on attenuated parasites, which are difficult to produce, and are only recommended for use in bovines under one year of age. When used in older animals, these vaccines may cause life-threatening clinical symptoms and eventually death. The development of a multi-subunit recombinant vaccine against B. bovis would be attractive from an economic standpoint and, most importantly, could be recommended for animals of any age. In the present study, recombinant ectodomains of MSA-2a1, MSA-2b and MSA-2c antigens were expressed in Pichia pastoris yeast as secreted soluble peptides. Results The antigens were purified to homogeneity, and biochemically and immunologically characterized. A vaccine formulation was obtained by emulsifying a mixture of the three peptides with the adjuvant Montanide ISA 720, which elicited high IgG antibody titers against each of the above antigens. IgG antibodies generated against each MSA-antigen recognized merozoites and significantly inhibited the invasion of bovine erythrocytes. Cellular immune responses were also detected, which were characterized by splenic and lymph node CD4+ T cells producing IFN-γ and TNF-α upon stimulation with the antigens MSA-2a1 or MSA-2c. Conclusions These data strongly suggest the high protective potential of the presented formulation, and we propose that it could be tested in vaccination trials of bovines challenged with B. bovis.

  11. Vaccinomics Approach for Designing Potential Peptide Vaccine by Targeting Shigella spp. Serine Protease Autotransporter Subfamily Protein SigA

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    Arafat Rahman Oany

    2017-01-01

    Full Text Available Shigellosis, a bacillary dysentery, is closely associated with diarrhoea in human and causes infection of 165 million people worldwide per year. Casein-degrading serine protease autotransporter of enterobacteriaceae (SPATE subfamily protein SigA, an outer membrane protein, exerts both cytopathic and enterotoxic effects especially cytopathic to human epithelial cell type-2 (HEp-2 and is shown to be highly immunogenic. In the present study, we have tried to impose the vaccinomics approach for designing a common peptide vaccine candidate against the immunogenic SigA of Shigella spp. At first, 44 SigA proteins from different variants of S. flexneri, S. dysenteriae, S. boydii, and S. sonnei were assessed to find the most antigenic protein. We retrieved 12 peptides based on the highest score for human leukocyte antigen (HLA supertypes analysed by NetCTL. Initially, these peptides were assessed for the affinity with MHC class I and class II alleles, and four potential core epitopes VTARAGLGY, FHTVTVNTL, HTTWTLTGY, and IELAGTLTL were selected. From these, FHTVTVNTL and IELAGTLTL peptides were shown to have 100% conservancy. Finally, IELAGTLTL was shown to have the highest population coverage (83.86% among the whole world population. In vivo study of the proposed epitope might contribute to the development of functional and unique widespread vaccine, which might be an operative alleyway to thwart dysentery from the world.

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

    DEFF Research Database (Denmark)

    Slovin, Susan F; Ragupathi, Govind; Fernandez, Celina

    2007-01-01

    vaccine of synthetic "self" antigens broke immunologic tolerance against two or more antigens in all 30 vaccinated patients, was safe, but antibody titers against several of the antigens were lower than those seen in individual monovalent trials. No impact on PSA slope was detected. We address......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...... and mixed with QS-21. Eight vaccinations were administered over 13 months. All 30 patients had significant elevations in antibody titers to at least two of the six antigens; 22 patients had increased reactivity with FACS. These serologic responses were lower than that seen previously in patients treated...

  13. Characterization and standardization of Sabin based inactivated polio vaccine: proposal for a new antigen unit for inactivated polio vaccines.

    Science.gov (United States)

    Westdijk, Janny; Brugmans, Debbie; Martin, Javier; van't Oever, Aart; Bakker, Wilfried A M; Levels, Lonneke; Kersten, Gideon

    2011-04-18

    GMP-batches of Sabin-IPV were characterized for their antigenic and immunogenic properties. Antigenic fingerprints of Sabin-IPV reveal that the D-antigen unit is not a fixed amount of antigen but depends on antibody and assay type. Instead of the D-antigen unit we propose standardization of IPV based on a combination of protein amount for dose and D-antigenicity for quality of the vaccine. Although Sabin-IPV type 2 is less immunogenic than regular wild type IPV type 2, the immunogenicity (virus neutralizing titers) per microgram antigen for Sabin-IPV type 2 is in the same order as for wild type serotypes 1 and 3. The latter observations are in line with data from human trials. This suggests that a higher dose of Sabin-IPV type 2 to compensate for the lower rat immunogenicity may not be necessary. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Current Peptide and Protein Candidates Challenging HIV Therapy beyond the Vaccine Era

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    Koollawat Chupradit

    2017-09-01

    Full Text Available Human immunodeficiency virus (HIV is a causative agent of acquired immune deficiency syndrome (AIDS. Highly active antiretroviral therapy (HAART can slow down the replication of HIV-1, leading to an improvement in the survival of HIV-1-infected patients. However, drug toxicities and poor drug administration has led to the emergence of a drug-resistant strain. HIV-1 immunotherapy has been continuously developed, but antibody therapy and HIV vaccines take time to improve its efficiency and have limitations. HIV-1-specific chimeric antigen receptor (CAR-based immunotherapy founded on neutralizing antibodies is now being developed. In HIV-1 therapy, anti-HIV chimeric antigen receptors showed promising data in the suppression of HIV-1 replication; however, autologous transfusion is still a problem. This has led to the development of effective peptides and proteins for an alternative HIV-1 treatment. In this paper, we provide a comprehensive review of potent anti-HIV-1 peptides and proteins that reveal promising therapeutic activities. The inhibitory mechanisms of each therapeutic molecule in the different stages of the HIV-1 life cycle will be discussed herein.

  15. Peptide-based subunit vaccine against hookworm infection.

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    Mariusz Skwarczynski

    Full Text Available Hookworms infect more people than HIV and malaria combined, predominantly in third world countries. Treatment of infection with chemotherapy can have limited efficacy and re-infections after treatment are common. Heavy infection often leads to debilitating diseases. All these factors suggest an urgent need for development of vaccine. In an attempt to develop a vaccine targeting the major human hookworm, Necator americanus, a B-cell peptide epitope was chosen from the apical enzyme in the hemoglobin digestion cascade, the aspartic protease Na-APR-1. The A(291Y alpha helical epitope is known to induce neutralizing antibodies that inhibit the enzymatic activity of Na-APR-1, thus reducing the capacity for hookworms to digest hemoglobin and obtain nutrients. A(291Y was engineered such that it was flanked on both termini by a coil-promoting sequence to maintain native conformation, and subsequently incorporated into a Lipid Core Peptide (LCP self-adjuvanting system. While A(291Y alone or the chimeric epitope with or without Freund's adjuvants induced negligible IgG responses, the LCP construct incorporating the chimeric peptide induced a strong IgG response in mice. Antibodies produced were able to bind to and completely inhibit the enzymatic activity of Na-APR-1. The results presented show that the new chimeric LCP construct can induce effective enzyme-neutralising antibodies in mice, without the help of any additional toxic adjuvants. This approach offers promise for the development of vaccines against helminth parasites of humans and their livestock and companion animals.

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

    NARCIS (Netherlands)

    Weinert, Brian T.; Krishnadath, Kausilia K.; Milano, Francesca; Pedersen, Ayako W.; Claesson, Mogens H.; Zocca, Mai-Britt

    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

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

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    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

  18. 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...... assessed the influence of helminth infection on vaccine-induced immune responses in a phase I clinical trial of the malaria vaccine candidate GMZ2. METHODS: Twenty Gabonese preschool-age children were vaccinated with GMZ2, a blood stage malaria vaccine candidate. Humoral immune response against the vaccine...... antigens and parasitological status were assessed. Vaccine-specific antibody concentrations and memory B-cell numbers were compared in worm infected and non-infected participants. RESULTS: Antibody response to GMZ2 was 3.4-fold (95% confidence interval: 1.6, 7.4) higher in Trichuris trichiura negative...

  19. Successful adjuvant-free vaccination of BALB/c mice with mutated amyloid β peptides

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    Wahi Monika M

    2008-02-01

    Full Text Available Abstract Background A recent human clinical trial of an Alzheimer's disease (AD vaccine using amyloid beta (Aβ 1–42 plus QS-21 adjuvant produced some positive results, but was halted due to meningoencephalitis in some participants. The development of a vaccine with mutant Aβ peptides that avoids the use of an adjuvant may result in an effective and safer human vaccine. Results All peptides tested showed high antibody responses, were long-lasting, and demonstrated good memory response. Epitope mapping indicated that peptide mutation did not lead to epitope switching. Mutant peptides induced different inflammation responses as evidenced by cytokine profiles. Ig isotyping indicated that adjuvant-free vaccination with peptides drove an adequate Th2 response. All anti-sera from vaccinated mice cross-reacted with human Aβ in APP/PS1 transgenic mouse brain tissue. Conclusion Our study demonstrated that an adjuvant-free vaccine with different Aβ peptides can be an effective and safe vaccination approach against AD. This study represents the first report of adjuvant-free vaccines utilizing Aβ peptides carrying diverse mutations in the T-cell epitope. These largely positive results provide encouragement for the future of the development of human vaccinations for AD.

  20. Expression and Immunogenicity of the Mycobacterial Ag85B/ESAT-6 Antigens Produced in Transgenic Plants by Elastin-Like Peptide Fusion Strategy

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    Doreen Manuela Floss

    2010-01-01

    Full Text Available This study explored a novel system combining plant-based production and the elastin-like peptide (ELP fusion strategy to produce vaccinal antigens against tuberculosis. Transgenic tobacco plants expressing the mycobacterial antigens Ag85B and ESAT-6 fused to ELP (TBAg-ELP were generated. Purified TBAg-ELP was obtained by the highly efficient, cost-effective, inverse transition cycling (ICT method and tested in mice. Furthermore, safety and immunogenicity of the crude tobacco leaf extracts were assessed in piglets. Antibodies recognizing mycobacterial antigens were produced in mice and piglets. A T-cell immune response able to recognize the native mycobacterial antigens was detected in mice. These findings showed that the native Ag85B and ESAT-6 mycobacterial B- and T-cell epitopes were conserved in the plant-expressed TBAg-ELP. This study presents the first results of an efficient plant-expression system, relying on the elastin-like peptide fusion strategy, to produce a safe and immunogenic mycobacterial Ag85B-ESAT-6 fusion protein as a potential vaccine candidate against tuberculosis.

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

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    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.

  2. Phase I clinical study of anti-apoptosis protein, survivin-derived peptide vaccine therapy for patients with advanced or recurrent colorectal cancer

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    Minamida Hidetoshi

    2004-06-01

    Full Text Available Abstract Survivin is a member of the inhibitor of apoptosis protein (IAP family containing a single baculovirus IAP repeat domain. It is expressed during fetal development but becomes undetectable in terminally differentiated normal adult tissues. We previously reported that survivin and its splicing variant survivin-2B was expressed abundantly in various types of tumor tissues as well as tumor cell lines and was suitable as a target antigen for active-specific anti-cancer immunization. Subsequently, we identified an HLA-A24-restricted antigenic peptide, survivin-2B80-88 (AYACNTSTL recognized by CD8+ cytotoxic T lymphocytes (CTLs. We, therefore, started a phase I clinical study assessing the efficacy of survivin-2B peptide vaccination in patients with advanced or recurrent colorectal cancer expressing survivin. Vaccinations with survivin-2B peptide were given subcutaneously six times at 14-day intervals. Of 15 patients who finished receiving the vaccination schedule, three suffered slight toxicities, including anemia (grade 2, general malaise (grade 1, and fever (grade 1. No severe adverse events were observed in any patient. In 6 patients, tumor marker levels (CEA and CA19-9 decreased transiently during the period of vaccination. Slight reduction of the tumor volume was observed in one patient, which was considered a minor responder. No changes were noted in three patients while the remaining eleven patients experienced tumor progression. Analysis of peripheral blood lymphocytes of one patient using HLA-A24/peptide tetramers revealed an increase in peptide-specific CTL frequency from 0.09% to 0.35% of CD8+ T cells after 4 vaccinations. This phase I clinical study indicates that survivin-2B peptide-based vaccination is safe and should be further considered for potential immune and clinical efficacy in HLA-A24-expression patients with colorectal cancer.

  3. Prime-Boost Vaccination Using Chemokine-Fused gp120 DNA and HIV Envelope Peptides Activates Both Immediate and Long-Term Memory Cellular Responses in Rhesus Macaques

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    Hong Qin

    2010-01-01

    Full Text Available HIV vaccine candidates with improved immunogenicity and induction of mucosal T-cell immunity are needed. A prime-boost strategy using a novel HIV glycoprotein 120 DNA vaccine was employed to immunize rhesus macaques. The DNA vaccine encoded a chimeric gp120 protein in fusion with monocyte chemoattractant protein-3, which was hypothesized to improve the ability of antigen-presenting cells to capture viral antigen through chemokine receptor-mediated endocytosis. DNA vaccination induced virus-reactive T cells in peripheral blood, detectable by T cell proliferation, INFγ ELISPOT and sustained IL-6 production, without humoral responses. With a peptide-cocktail vaccine containing a set of conserved polypeptides of HIV-1 envelope protein, given by nasogastric administration, primed T-cell immunity was significantly boosted. Surprisingly, long-term and peptide-specific mucosal memory T-cell immunity was detected in both vaccinated macaques after one year. Therefore, data from this investigation offer proof-of-principle for potential effectiveness of the prime-boost strategy with a chemokine-fused gp120 DNA and warrant further testing in the nonhuman primate models for developing as a potential HIV vaccine candidate in humans.

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

    DEFF Research Database (Denmark)

    Schmidt, Signe Tandrup; Foged, Camilla; Korsholm, Karen Smith

    2016-01-01

    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......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...... of immunostimulators and antigens, respectively, into liposomes, and the choice of immunostimulator should ideally be based on knowledge regarding the specific PRR expression profile of the target APCs. Here, we review state-of-the-art formulation approaches employed for the inclusion of immunostimulators and subunit...

  5. A recombinant modified vaccinia ankara vaccine encoding Epstein-Barr Virus (EBV) target antigens: a phase I trial in UK patients with EBV-positive cancer.

    Science.gov (United States)

    Taylor, Graham S; Jia, Hui; Harrington, Kevin; Lee, Lip Wai; Turner, James; Ladell, Kristin; Price, David A; Tanday, Manjit; Matthews, Jen; Roberts, Claudia; Edwards, Ceri; McGuigan, Lesley; Hartley, Andrew; Wilson, Steve; Hui, Edwin P; Chan, Anthony T C; Rickinson, Alan B; Steven, Neil M

    2014-10-01

    Epstein-Barr virus (EBV) is associated with several cancers in which the tumor cells express EBV antigens EBNA1 and LMP2. A therapeutic vaccine comprising a recombinant vaccinia virus, MVA-EL, was designed to boost immunity to these tumor antigens. A phase I trial was conducted to demonstrate the safety and immunogenicity of MVA-EL across a range of doses. Sixteen patients in the United Kingdom (UK) with EBV-positive nasopharyngeal carcinoma (NPC) received three intradermal vaccinations of MVA-EL at 3-weekly intervals at dose levels between 5 × 10(7) and 5 × 10(8) plaque-forming units (pfu). Blood samples were taken at screening, after each vaccine cycle, and during the post-vaccination period. T-cell responses were measured using IFNγ ELISpot assays with overlapping EBNA1/LMP2 peptide mixes or HLA-matched epitope peptides. Polychromatic flow cytometry was used to characterize functionally responsive T-cell populations. Vaccination was generally well tolerated. Immunity increased after vaccination to at least one antigen in 8 of 14 patients (7/14, EBNA1; 6/14, LMP2), including recognition of epitopes that vary between EBV strains associated with different ethnic groups. Immunophenotypic analysis revealed that vaccination induced differentiation and functional diversification of responsive T-cell populations specific for EBNA1 and LMP2 within the CD4 and CD8 compartments, respectively. MVA-EL is safe and immunogenic across diverse ethnicities and thus suitable for use in trials against different EBV-positive cancers globally as well as in South-East Asia where NPC is most common. The highest dose (5 × 10(8) pfu) is recommended for investigation in current phase IB and II trials. ©2014 American Association for Cancer Research.

  6. Antigen-Sparing and Enhanced Efficacy of Multivalent Vaccines Adjuvanted with Immunopotentiators in Chickens

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    Peipei Wu

    2017-05-01

    Full Text Available We previously described that immunopotentiators, CVCVA5, increased the efficacy of H5 and H9 subtype avian influenza vaccines in chickens, ducks, and geese. In this study, we further investigated the effects of the CVCVA5 for improving the efficacy of other univalent or multivalent inactivated vaccines. The immune response administrated with half-dose of monovalent vaccine plus CVCVA5 were higher than those of one dose of monovalent vaccine without immunopotentiators as measured by levels of antibodies from serum, tears and bronchoalveolar lavage fluids, and cytokines of IFNγ and IL-4 from serum. Vaccines included the univalent vaccine of Newcastle Disease virus (ND, Egg Drop Syndrome virus (EDS, Infectious Bronchitis virus (IB, and Infectious Bursal Disease virus (IBD. The CVCVA5 also improved the immune response of both ND and IBD vaccines with less dosage. The sterile protective immunity was monitored with one- or a half-dose of adjuvanted ND vaccine or one dose of adjuvanted IBD vaccine, respectively. The improved immune efficacy was observed in a half-dose of adjuvanted bivalent vaccines compared to one dose of vaccines without CVCVA5 as measured by the antibody levels, including bivalent vaccine of ND-H9, ND-IB, and ND-IBD. The CVCVA5 also boosted the immune efficacy of the tetravalent vaccine (ND-IB-EDS-H9. A half-dose of adjuvanted commercial vaccine or 75% antigen-sparing adjuvanted vaccine elicited similar antibody levels to those of one dose non-adjuvanted commercial vaccines. The CVCVA5 improved the effect of a booster vaccination as measured by the antibody levels against H5 or H9 virus antigens, in which chickens primed with the adjuvanted ND-IB vaccines given a booster with H5–H9 bivalent vaccines without CVCVA5 using 5-day intervals. The inflammatory response may contribute to these additional effects by increasing the levels of IFNγ and IL-4 after the injection of the adjuvanted ND-IB vaccines. Results indicated that the

  7. Oxidative stress can alter the antigenicity of immunodominant peptides

    DEFF Research Database (Denmark)

    Weiskopf, Daniela; Schwanninger, Angelika; Weinberger, Birgit

    2010-01-01

    APCs operate frequently under oxidative stress induced by aging, tissue damage, pathogens, or inflammatory responses. Phagocytic cells produce peroxides and free-radical species that facilitate pathogen clearance and can in the case of APCs, also lead to oxidative modifications of antigenic prote...

  8. A randomized placebo-controlled phase Ia malaria vaccine trial of two virosome-formulated synthetic peptides in healthy adult volunteers.

    Directory of Open Access Journals (Sweden)

    Blaise Genton

    2007-10-01

    Full Text Available Influenza virosomes represent an innovative human-compatible antigen delivery system that has already proven its suitability for subunit vaccine design. The aim of the study was to proof the concept that virosomes can also be used to elicit high titers of antibodies against synthetic peptides. The specific objective was to demonstrate the safety and immunogenicity of two virosome-formulated P. falciparum protein derived synthetic peptide antigens given in two different doses alone or in combination.The design was a single blind, randomized, placebo controlled, dose-escalating study involving 46 healthy Caucasian volunteers aged 18-45 years. Five groups of 8 subjects received virosomal formulations containing 10 microg or 50 microg of AMA 49-CPE, an apical membrane antigen-1 (AMA-1 derived synthetic phospatidylethanolamine (PE-peptide conjugate or 10 ug or 50 ug of UK39, a circumsporozoite protein (CSP derived synthetic PE-peptide conjugate or 50 ug of both antigens each. A control group of 6 subjects received unmodified virosomes. Virosomal formulations of the antigens (designated PEV301 and PEV302 for the AMA-1 and the CSP virosomal vaccine, respectively or unmodified virosomes were injected i. m. on days 0, 60 and 180. In terms of safety, no serious or severe adverse events (AEs related to the vaccine were observed. 11/46 study participants reported 16 vaccine related local AEs. Of these 16 events, all being pain, 4 occurred after the 1(st, 7 after the 2(nd and 5 after the 3(rd vaccination. 6 systemic AEs probably related to the study vaccine were reported after the 1(st injection, 10 after the 2(nd and 6 after the 3(rd. Generally, no difference in the distribution of the systemic AEs between either the doses applied (10 respectively 50 microg or the synthetic antigen vaccines (PEV301 and PEV302 used for immunization was found. In terms of immunogenicity, both PEV301 and PEV302 elicited already after two injections a synthetic peptide

  9. An M2e-based synthetic peptide vaccine for influenza A virus confers heterosubtypic protection from lethal virus challenge.

    Science.gov (United States)

    Ma, Ji-Hong; Yang, Fu-Ru; Yu, Hai; Zhou, Yan-Jun; Li, Guo-Xin; Huang, Meng; Wen, Feng; Tong, Guangzhi

    2013-07-09

    Vaccination is considered as the most effective preventive method to control influenza. The hallmark of influenza virus is the remarkable variability of its major surface glycoproteins, HA and NA, which allows the virus to evade existing anti-influenza immunity in the target population. So it is necessary to develop a novel vaccine to control animal influenza virus. Also we know that the ectodomain of influenza matrix protein 2 (M2e) is highly conserved in animal influenza A viruses, so a vaccine based on the M2e could avoid several drawbacks of the traditional vaccines. In this study we designed a novel tetra-branched multiple antigenic peptide (MAP) based vaccine, which was constructed by fusing four copies of M2e to one copy of foreign T helper (Th) cell epitope, and then investigated its immune responses. Our results show that the M2e-MAP induced strong M2e-specific IgG antibody,which responses following 2 doses immunization in the presence of Freunds' adjuvant. M2e-MAP vaccination limited viral replication substantially. Also it could attenuate histopathological damage in the lungs of challenged mice and counteracted weight loss. M2e-MAP-based vaccine protected immunized mice against the lethal challenge with PR8 virus. Based on these findings, M2e-MAP-based vaccine seemed to provide useful information for the research of M2e-based influenza vaccine. Also it show huge potential to study vaccines for other similarly viruses.

  10. Multiple Antigen Peptide Vaccines against Plasmodium falciparum Malaria

    Science.gov (United States)

    2010-01-01

    Robert A. Boykins/ Victoria Majam,l Hong Zheng,1 Rana Chattopadhyay,l Patricia de Ia Vcga,3 J. Kathleen Moch ,J J. David Hayncs,3 Igor M. Belyakov,2...K. Moch , and D. S. Smoot. 2002. Erythroc-ytic malaria growth or invasion inhibition assays with emphasis on suspension culture GIA. Methods Mol. Med

  11. 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...... in 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 tumor cell...

  12. Structural Basis for Antigenic Peptide Recognition and Processing by Endoplasmic Reticulum (ER) Aminopeptidase 2.

    Science.gov (United States)

    Mpakali, Anastasia; Giastas, Petros; Mathioudakis, Nikolas; Mavridis, Irene M; Saridakis, Emmanuel; Stratikos, Efstratios

    2015-10-23

    Endoplasmic reticulum (ER) aminopeptidases process antigenic peptide precursors to generate epitopes for presentation by MHC class I molecules and help shape the antigenic peptide repertoire and cytotoxic T-cell responses. To perform this function, ER aminopeptidases have to recognize and process a vast variety of peptide sequences. To understand how these enzymes recognize substrates, we determined crystal structures of ER aminopeptidase 2 (ERAP2) in complex with a substrate analogue and a peptidic product to 2.5 and 2.7 Å, respectively, and compared them to the apo-form structure determined to 3.0 Å. The peptides were found within the internal cavity of the enzyme with no direct access to the outside solvent. The substrate analogue extends away from the catalytic center toward the distal end of the internal cavity, making interactions with several shallow pockets along the path. A similar configuration was evident for the peptidic product, although decreasing electron density toward its C terminus indicated progressive disorder. Enzymatic analysis confirmed that visualized interactions can either positively or negatively impact in vitro trimming rates. Opportunistic side-chain interactions and lack of deep specificity pockets support a limited-selectivity model for antigenic peptide processing by ERAP2. In contrast to proposed models for the homologous ERAP1, no specific recognition of the peptide C terminus by ERAP2 was evident, consistent with functional differences in length selection and self-activation between these two enzymes. Our results suggest that ERAP2 selects substrates by sequestering them in its internal cavity and allowing opportunistic interactions to determine trimming rates, thus combining substrate permissiveness with sequence bias. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Fine-mapping of immunodominant linear B-cell epitopes of the Staphylococcus aureus SEB antigen using short overlapping peptides.

    Directory of Open Access Journals (Sweden)

    Zhuo Zhao

    Full Text Available Staphylococcal enterotoxin B (SEB is one of the most potent Staphylococcus aureus exotoxins (SEs. Due to its conserved sequence and stable structure, SEB might be a good candidate antigen for MRSA vaccines. Although cellular immune responses to SEB are well-characterized, much less is known regarding SEB-specific humoral immune responses, particularly regarding detailed epitope mapping. In this study, we utilized a recombinant nontoxic mutant of SEB (rSEB and an AlPO4 adjuvant to immunize BALB/c mice and confirmed that rSEB can induce a high antibody level and effective immune protection against MRSA infection. Next, the antisera of immunized mice were collected, and linear B cell epitopes within SEB were finely mapped using a series of overlapping synthetic peptides. Three immunodominant B cell epitopes of SEB were screened by ELISA, including a novel epitope, SEB205-222, and two known epitopes, SEB97-114 and SEB247-261. Using truncated peptides, an ELISA was performed with peptide-KLH antisera, and the core sequence of the three immunodominant B cell epitopes were verified as SEB97-112, SEB207-222, and SEB247-257. In vitro, all of the immunodominant epitope-specific antisera (anti-SEB97-112, anti-SEB207-222 and anti-SEB247-257 were observed to inhibit SEB-induced T cell mitogenesis and cytokine production from splenic lymphocytes of BALB/c mice. The homology analysis indicated that SEB97-112 and SEB207-222 were well-conserved among different Staphylococcus aureus strains. The 3D crystal structure of SEB indicated that SEB97-112 was in the loop region inside SEB, whereas SEB207-222 and SEB247-257 were in the β-slice region outside SEB. In summary, the fine-mapping of linear B-cell epitopes of the SEB antigen in this study will be useful to understand anti-SEB immunity against MRSA infection further and will be helpful to optimize MRSA vaccine designs that are based on the SEB antigen.

  14. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Differing patterns of selection and geospatial genetic diversity within two leading Plasmodium vivax candidate vaccine antigens.

    Directory of Open Access Journals (Sweden)

    Christian M Parobek

    2014-04-01

    Full Text Available Although Plasmodium vivax is a leading cause of malaria around the world, only a handful of vivax antigens are being studied for vaccine development. Here, we investigated genetic signatures of selection and geospatial genetic diversity of two leading vivax vaccine antigens--Plasmodium vivax merozoite surface protein 1 (pvmsp-1 and Plasmodium vivax circumsporozoite protein (pvcsp. Using scalable next-generation sequencing, we deep-sequenced amplicons of the 42 kDa region of pvmsp-1 (n = 44 and the complete gene of pvcsp (n = 47 from Cambodian isolates. These sequences were then compared with global parasite populations obtained from GenBank. Using a combination of statistical and phylogenetic methods to assess for selection and population structure, we found strong evidence of balancing selection in the 42 kDa region of pvmsp-1, which varied significantly over the length of the gene, consistent with immune-mediated selection. In pvcsp, the highly variable central repeat region also showed patterns consistent with immune selection, which were lacking outside the repeat. The patterns of selection seen in both genes differed from their P. falciparum orthologs. In addition, we found that, similar to merozoite antigens from P. falciparum malaria, genetic diversity of pvmsp-1 sequences showed no geographic clustering, while the non-merozoite antigen, pvcsp, showed strong geographic clustering. These findings suggest that while immune selection may act on both vivax vaccine candidate antigens, the geographic distribution of genetic variability differs greatly between these two genes. The selective forces driving this diversification could lead to antigen escape and vaccine failure. Better understanding the geographic distribution of genetic variability in vaccine candidate antigens will be key to designing and implementing efficacious vaccines.

  16. Serum reactome induced by Bordetella pertussis infection and Pertussis vaccines: qualitative differences in serum antibody recognition patterns revealed by peptide microarray analysis.

    Science.gov (United States)

    Valentini, Davide; Ferrara, Giovanni; Advani, Reza; Hallander, Hans O; Maeurer, Markus J

    2015-07-01

    Pertussis (whooping cough) remains a public health problem despite extensive vaccination strategies. Better understanding of the host-pathogen interaction and the detailed B. pertussis (Bp) target recognition pattern will help in guided vaccine design. We characterized the specific epitope antigen recognition profiles of serum antibodies ('the reactome') induced by whooping cough and B. pertussis (Bp) vaccines from a case-control study conducted in 1996 in infants enrolled in a Bp vaccine trial in Sweden (Gustafsson, NEJM, 1996, 334, 349-355). Sera from children with whooping cough, vaccinated with Diphtheria Tetanus Pertussis (DTP) whole-cell (wc), acellular 5 (DPTa5), or with the 2 component (a2) vaccines and from infants receiving only DT (n=10 for each group) were tested with high-content peptide microarrays containing 17 Bp proteins displayed as linear (n=3175) peptide stretches. Slides were incubated with serum and peptide-IgG complexes detected with Cy5-labeled goat anti-human IgG and analyzed using a GenePix 4000B microarray scanner, followed by statistical analysis, using PAM (Prediction Analysis for Microarrays) and the identification of uniquely recognized peptide epitopes. 367/3,085 (11.9%) peptides were recognized in 10/10 sera from children with whooping cough, 239 (7.7%) in DTPwc, 259 (8.4%) in DTPa5, 105 (3.4%) DTPa2, 179 (5.8%) in the DT groups. Recognition of strongly recognized peptides was similar between whooping cough and DPTwc, but statistically different between whooping cough vs. DTPa5 (p<0.05), DTPa2 and DT (p<0.001 vs. both) vaccines. 6/3,085 and 2/3,085 peptides were exclusively recognized in (10/10) sera from children with whooping cough and DTPa2 vaccination, respectively. DTPwc resembles more closely the whooping cough reactome as compared to acellular vaccines. We could identify a unique recognition signature common for each vaccination group (10/10 children). Peptide microarray technology allows detection of subtle differences in

  17. Protection of ewes against Teladorsagia circumcincta infection in the periparturient period by vaccination with recombinant antigens.

    Science.gov (United States)

    Nisbet, Alasdair J; McNeilly, Tom N; Greer, Andrew W; Bartley, Yvonne; Oliver, E Margaret; Smith, Stephen; Palarea-Albaladejo, Javier; Matthews, Jacqueline B

    2016-09-15

    Teladorsagiosis is a major production-limiting disease in ruminants in temperate regions throughout the world and one of the key interventions in the management of the disease is the prevention of pasture contamination with Teladorsagia circumcincta eggs by ewes during the periparturient relaxation in immunity which occurs in the period around lambing. Here, we describe the immunisation of twin-bearing ewes with a T. circumcincta recombinant subunit vaccine and the impact that vaccination has on their immune responses and shedding of parasite eggs during a continuous T. circumcincta challenge period spanning late gestation and lactation. In ewes which displayed a clear periparturient relaxation in immunity, vaccination resulted in a 45% reduction in mean cumulative faecal egg count (cFEC, p=0.027) compared to control (immunised with adjuvant only) ewes. Recombinant antigen-specific IgG and IgA, which bound each of the vaccine antigens, were detected in the serum of vaccinated ewes following each immunisation and in colostrum taken from vaccinated ewes post-partum whereas low levels of antigen-specific IgG were detected in serum and colostrum from control ewes. Antigen-specific IgG and IgA levels in blood collected within 48h of birth from lambs largely reflected those in the colostrum of their ewes. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Leptospira spp. vaccinal antibodies do not react with Borrelia burgdorferi peptides used in the AccuPlex 4.

    Science.gov (United States)

    Caress, Amber L; Moroff, Scott; Lappin, Michael R

    2017-11-01

    We attempted to determine if Leptospira spp. antibodies induced by vaccination would cross-react with Borrelia burgdorferi antigens used in a commercial automated immunofluorescent assay (AccuPlex 4 BioCD; Antech). Staff- and student-owned dogs ( n = 31) were recruited at a veterinary teaching hospital in a B. burgdorferi nonendemic area. The dogs were randomized and administered 1 of 4 commercial Leptospira spp. vaccines that contained serovars Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona, then booster vaccinated 3 wk later. Blood was collected on weeks 0, 3, 4, 8, and 12. After confirming that maximal Leptospira spp. titers occurred on week 4, aliquots of sera from week 4 were shipped frozen for analysis of B. burgdorferi antibodies against OspA, OspC, OspF, P39, and SLP with the AccuPlex system. Week 4 sera from all 31 dogs had a titer of 1:100 for at least 1 Leptospira spp. serovar. Titers of 1:800 or greater were detected against multiple serovars in 27 dogs. None of the samples contained antibodies against the B. burgdorferi OspA, OspC, OspF, P39, and SLP peptides used in the commercial assay. The B. burgdorferi peptides used in the AccuPlex system do not recognize naturally occurring Leptospira spp. antibodies or those induced by the commercial Leptospira spp. vaccines administered in our study.

  19. Recombinant protective antigen 102 (rPA102): profile of a second-generation anthrax vaccine.

    Science.gov (United States)

    Keitel, Wendy A

    2006-08-01

    Recent terrorist attacks involving the use of Bacillus anthracis spores have stimulated interest in the development of new vaccines for anthrax prevention. Studies of the pathogenesis of anthrax and of the immune responses following infection and immunization underscore the pivotal role that antibodies to the protective antigen play in protection. The most promising vaccine candidates contain purified recombinant protective antigen. Clinical trials of one of these, recombinant protective antigen (rPA)102, are underway. Initial results suggest that rPA102 is well tolerated and immunogenic. Additional trials are necessary to identify optimal formulations and immunization regimens for pre- and postexposure prophylaxis. Future licensure of these and other candidate vaccines will depend on their safety and immunogenicity profiles in humans, and their ability to confer protection in animal models of inhalational anthrax.

  20. Immunogenicity of meningococcal PorA antigens in OMV vaccines

    NARCIS (Netherlands)

    Luijkx, T.A.

    2006-01-01

    For the prevention of meningococcal infection caused by group B meningococci, the Netherlands Vaccine Institute (NVI) has developed a hexavalent Porin A (PorA) based Outer Membrane Vesicle (OMV) vaccine (Hexamen). In various clinical studies with HexaMen, differences in the immune responses to the

  1. THE ANTIGEN-SPECIFIC CELL IN VITRO TESTS FOR POST-VACCINATION ANTIPLAGUE IMMUNITY FORMATION

    Directory of Open Access Journals (Sweden)

    A. N. Kulichenko

    2017-01-01

    Full Text Available The possibility of post-vaccination anti-plague immunity evaluation was researched using antigen-stimulated cells tests in vitro and cytometry analysis. The object of study — the blood samples of 17 people immunised by the live plague vaccine (Yersinia pestis EV epicutaneously. Blood taking was carried out before vaccination and after immunisation on 7 and on 21 days, in 3 and in 6 months. Intensity antigen reactivity of lymphocytes was detected by cell tests in vitro, analysing markers of early (CD45+CD3+CD25+ and late (CD45+CD3+HLA-DR+ lymphocyte activation using flow cytometry. The complex of water-soluble Y. pestis antigens and allergen — pestin PP was tested as antigen. The high stimulating potential was defined of the water-soluble antigens Y. pestis complex. It is shown that coefficient of stimulation of relative level T- lymphocytes which express receptors for IL-2 was positive for all observation times after immunisation. The coefficient of stimulation had maximum values at 21 days (56.37% and at 3 (47.41% months. In identifying HLADR-positive lymphocytes before vaccination, the negative coefficient of stimulation was indicated on 7 and 21 days and the positive coefficient of stimulation was indicated at 3 and at 6 months. Analysis of intensity expression of early and late lymphocyte activation markers dynamics showed the possibility and prospect of application of cellular in vitro tests for the laboratory evaluation of specific reactivity of cellular immunity in both the early (7 days and late (6 months periods after vaccination. The results can be the basis for developing a new algorithm for assessment of immunological effectiveness of vaccination people against plague. It is the algorithm based on the identification of lymphocyte activation markers by antigen stimulation in conditions in vitro.

  2. Design and synthesis of multiple antigenic peptides and their application for dengue diagnosis.

    Science.gov (United States)

    Rai, Reeta; Dubey, Sameer; Santosh, K V; Biswas, Ashutosh; Mehrotra, Vinit; Rao, D N

    2017-09-01

    Major difficulty in development of dengue diagnostics is availability of suitable antigens. To overcome this, we made an attempt to develop a peptide based diagnosis which offers significant advantage over other methods. With the help of in silico methods, two epitopes were selected from envelope protein and three from NS1 protein of dengue virus. These were synthesized in combination as three multiple antigenic peptides (MAPs). We have tested 157 dengue positive sera confirmed for NS1 antigen. MAP1 showed 96.81% sera positive for IgM and 68.15% positive for IgG. MAP2 detected 94.90% IgM and 59.23% IgG positive sera. MAP3 also detected 96.17% IgM and 59.87% IgG positive sera. To the best of our knowledge this is the first study describing the use of synthetic multiple antigenic peptides for the diagnosis of dengue infection. This study describes MAPs as a promising tool for the use in serodiagnosis of dengue. Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  3. Definition of natural T cell antigens with mimicry epitopes obtained from dedicated synthetic peptide libraries.

    Science.gov (United States)

    Hiemstra, H S; van Veelen, P A; Schloot, N C; Geluk, A; van Meijgaarden, K E; Willemen, S J; Leunissen, J A; Benckhuijsen, W E; Amons, R; de Vries, R R; Roep, B O; Ottenhoff, T H; Drijfhout, J W

    1998-10-15

    Progress has recently been made in the use of synthetic peptide libraries for the identification of T cell-stimulating ligands. T cell epitopes identified from synthetic libraries are mimics of natural epitopes. Here we show how the mimicry epitopes obtained from synthetic peptide libraries enable unambiguous identification of natural T cell Ags. Synthetic peptide libraries were screened with Mycobacterium tuberculosis-reactive and -autoreactive T cell clones. In two cases, database homology searches with mimicry epitopes isolated from a dedicated synthetic peptide library allowed immediate identification of the natural antigenic protein. In two other cases, an amino acid pattern that reflected the epitope requirements of the T cell was determined by substitution and omission mixture analysis. Subsequently, the natural Ag was identified from databases using this refined pattern. This approach opens new perspectives for rapid and reliable Ag definition, representing a feasible alternative to the biochemical and genetic approaches described thus far.

  4. Influence of virus strain and antigen mass on efficacy of H5 avian influenza inactivated vaccines.

    Science.gov (United States)

    Swayne, D E; Beck, J R; Garcia, M; Stone, H D

    1999-06-01

    The influence of vaccine strain and antigen mass on the ability of inactivated avian influenza (AI) viruses to protect chicks from a lethal, highly pathogenic (HP) AI virus challenge was studied. Groups of 4-week-old chickens were immunized with inactivated vaccines containing one of 10 haemagglutinin subtype H5 AI viruses, one heterologous H7 AI virus or normal allantoic fluid (sham), and challenged 3 weeks later by intra-nasal inoculation with a HP H5 chicken-origin AI virus. All 10 H5 vaccines provided good protection from clinical signs and death, and produced positive serological reactions on agar gel immunodiffusion and haemagglutination inhibition tests. In experiment 1, challenge virus was recovered from the oropharynx of 80% of chickens in the H5 vaccine group. In five H5 vaccine groups, challenge virus was not recovered from the cloaca of chickens. In the other five H5 vaccine groups, the number of chickens with detection of challenge virus from the cloaca was lower than in the sham group (P turkey/Wisconsin/68 (H5N9) was the best vaccine candidate of the H5 strains tested (PD50= 0.006 μg AI antigen). These data demonstrate that chickens vaccinated with inactivated H5 whole virus AI vaccines were protected from clinical signs and death, but usage of vaccine generally did not prevent infection by the challenge virus, as indicated by recovery of virus from the oropharynx. Vaccine use reduced cloacal detection rates, and quantity of virus shed from the cloaca and oropharynx in some vaccine groups, which would potentially reduce environmental contamination and disease transmission in the field.

  5. Safety of currently licensed hepatitis B surface antigen vaccines in the United States, Vaccine Adverse Event Reporting System (VAERS), 2005-2015.

    Science.gov (United States)

    Haber, Penina; Moro, Pedro L; Ng, Carmen; Lewis, Paige W; Hibbs, Beth; Schillie, Sarah F; Nelson, Noele P; Li, Rongxia; Stewart, Brock; Cano, Maria V

    2018-01-25

    Currently four recombinant hepatitis B (HepB) vaccines are in use in the United States. HepB vaccines are recommended for infants, children and adults. We assessed adverse events (AEs) following HepB vaccines reported to the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous reporting system. We searched VAERS for reports of AEs following single antigen HepB vaccine and HepB-containing vaccines (either given alone or with other vaccines), from January 2005 - December 2015. We conducted descriptive analyses and performed empirical Bayesian data mining to assess disproportionate reporting. We reviewed serious reports including reports of special interest. VAERS received 20,231 reports following HepB or HepB-containing vaccines: 10,291 (51%) in persons 18 years; for 1485 (7.3%) age was missing. Dizziness and nausea (8.4% each) were the most frequently reported AEs following a single antigen HepB vaccine: fever (23%) and injection site erythema (11%) were most frequent following Hep-containing vaccines. Of the 4444 (22%) reports after single antigen HepB vaccine, 303 (6.8%) were serious, including 45 deaths. Most commonly reported cause of death was Sudden Infant Death Syndrome (197). Most common non-death serious reports following single antigen HepB vaccines among infants aged children aged 1-23 months; infections and infestation (8) among persons age 2-18 years blood and lymphatic systemic disorders; and general disorders and administration site conditions among persons age >18 years. Most common vaccination error following single antigen HepB was incorrect product storage. Review current U.S.-licensed HepB vaccines administered alone or in combination with other vaccines did not reveal new or unexpected safety concerns. Vaccination errors were identified which indicate the need for training and education of providers on HepB vaccine indications and recommendations. Published by Elsevier Ltd.

  6. 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.

  7. 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. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  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 evide...... of VSAs, and how vaccines based on this type of antigens fit into the current global strategy to reduce, eliminate and eventually eradicate the burden of malaria....

  9. Formulation of influenza T cell peptides : in search of a universal influenza vaccine

    NARCIS (Netherlands)

    Soema, Peter Christiaan

    2015-01-01

    Current seasonal influenza vaccines rely on the induction of antibodies to neutralize the virus. However, influenza viruses frequently undergo genetic mutations due to antigenic drift and shift, altering the surface proteins hemagglutinin and neuraminidase to which antibodies usually bind. This

  10. SVMTriP: a method to predict antigenic epitopes using support vector machine to integrate tri-peptide similarity and propensity.

    Directory of Open Access Journals (Sweden)

    Bo Yao

    Full Text Available Identifying protein surface regions preferentially recognizable by antibodies (antigenic epitopes is at the heart of new immuno-diagnostic reagent discovery and vaccine design, and computational methods for antigenic epitope prediction provide crucial means to serve this purpose. Many linear B-cell epitope prediction methods were developed, such as BepiPred, ABCPred, AAP, BCPred, BayesB, BEOracle/BROracle, and BEST, towards this goal. However, effective immunological research demands more robust performance of the prediction method than what the current algorithms could provide. In this work, a new method to predict linear antigenic epitopes is developed; Support Vector Machine has been utilized by combining the Tri-peptide similarity and Propensity scores (SVMTriP. Applied to non-redundant B-cell linear epitopes extracted from IEDB, SVMTriP achieves a sensitivity of 80.1% and a precision of 55.2% with a five-fold cross-validation. The AUC value is 0.702. The combination of similarity and propensity of tri-peptide subsequences can improve the prediction performance for linear B-cell epitopes. Moreover, SVMTriP is capable of recognizing viral peptides from a human protein sequence background. A web server based on our method is constructed for public use. The server and all datasets used in the current study are available at http://sysbio.unl.edu/SVMTriP.

  11. Carrier protein influences immunodominance of a known epitope: implication in peptide vaccine design.

    Science.gov (United States)

    Ghosh, Moumita; Solanki, Ashish K; Roy, Koushik; Dhoke, Reema R; Ashish; Roy, Syamal

    2013-09-23

    We investigated how the processing of a given antigen by antigen presenting cells (APC) is dictated by the conformation of the antigen and how this governs the immunodominance hierarchy. To address the question, a known immunodominant sequence of bacteriophage lambda repressor N-terminal sequence 12-26 [λR(12-26)] was engineered at the N and C termini of a heterologous leishmanial protein, Kinetoplastid membrane protein-11 (KMP-11); the resulting proteins were defined as N-KMP-11 and C-KMP-11 respectively. The presence of λR(12-26) in N-KMP-11 and C-KMP-11 was established by western blot analysis with antibody to λR(12-26) peptide. N-KMP-11 but not C-KMP-11 could stimulate the anti λR(12-26) T-cell clonal population very efficiently in the presence of APCs. Priming of BALB/c mice with N-KMP-11 or C-KMP-11 generated similar levels of anti-KMP-11 IgG, but anti-λR(12-26) specific IgG was observed only upon priming with N-KMP-11. Interestingly, uptake of both N-KMP-11 and C-KMP-11 by APCs was similar but catabolism of N-KMP-11 but not C-KMP-11 was biphasic and fast at the initial time point. Kratky plots of small angle X-ray scattering showed that while N-KMP-11 adopts flexible Gaussian type of topology, C-KMP-11 prefers Globular nature. To show that KMP-11 is not unique as a carrier protein, an epitope (SPITBTNLBTMBK) of Plasmodium yoelii (PY) apical membrane protein 1[AMA-1 (136-148)], is placed at the C and N terminals of a dominant T-cell epitope of ovalbumin protein OVA(323-339) and the resulting peptides are defined as PY-OVA and OVA-PY respectively. Interestingly, only OVA-PY could stimulate anti-OVA T-cells and produce IgG response upon priming of BALB/c mice with it. Thus for rational design of peptide vaccine it is important to place the dominant epitope appropriately in the context of the carrier protein. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Peptide Probes Reveal a Hydrophobic Steric Ratchet in the Anthrax Toxin Protective Antigen Translocase.

    Science.gov (United States)

    Colby, Jennifer M; Krantz, Bryan A

    2015-11-06

    Anthrax toxin is a tripartite virulence factor produced by Bacillus anthracis during infection. Under acidic endosomal pH conditions, the toxin's protective antigen (PA) component forms a transmembrane channel in host cells. The PA channel then translocates its two enzyme components, lethal factor and edema factor, into the host cytosol under the proton motive force. Protein translocation under a proton motive force is catalyzed by a series of nonspecific polypeptide binding sites, called clamps. A 10-residue guest/host peptide model system, KKKKKXXSXX, was used to functionally probe polypeptide-clamp interactions within wild-type PA channels. The guest residues were Thr, Ala, Leu, Phe, Tyr, and Trp. In steady-state translocation experiments, the channel blocked most tightly with peptides that had increasing amounts of nonpolar surface area. Cooperative peptide binding was observed in the Trp-containing peptide sequence but not the other tested sequences. Trp substitutions into a flexible, uncharged linker between the lethal factor amino-terminal domain and diphtheria toxin A chain expedited translocation. Therefore, peptide-clamp sites in translocase channels can sense large steric features (like tryptophan) in peptides, and while these steric interactions may make a peptide translocate poorly, in the context of folded domains, they can make the protein translocate more rapidly presumably via a hydrophobic steric ratchet mechanism. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Immunogenicity of Mycobacterium avium subsp. paratuberculosis specific peptides for inclusion in a subunit vaccine against paratuberculosis

    DEFF Research Database (Denmark)

    Mikkelsen, Heidi; Tollefsen, S.; Olsen, I.

    Paratuberculosis in ruminants is caused by an infection with Mycobacterium avium subspecies paratuberculosis (MAP) and is a chronic disease characterized by granulomatous enteritis. Available vaccines against paratuberculosis consist of variations of whole bacteria with adjuvant showing various...... efficacies. The main problem with available vaccines is their interference with surveillance and diagnosis of bovine tuberculosis and paratuberculosis. Our ultimate aim is to develop a subunit vaccine consisting of selected MAP peptides, which allow differentiation of infected from vaccinated animals. Here......, 118 peptides were identified by in silico analysis and synthesized chemically. Peptides were tested for reactivity and immunogenicity with T-cell lines generated from PBMCs isolated from MAP infected goats and with blood samples from MAP infected calves. Immunogenicity of peptides was evaluated using...

  14. Full protection in mink against mink enteritis virus with new generation canine parvovirus vaccines based on synthetic peptide or recombinant protein

    DEFF Research Database (Denmark)

    Langeveld, J. P.; Kamstrup, Søren; Uttenthal, Åse

    1995-01-01

    Two recently developed vaccines—one based on synthetic peptide and one based on recombinant capsid protein—fully protected dogs against heavy experimental canine parvovirus (CPV) infection. The high sequence homology (>98%) and antigenic similarity between CPV and mink enteritis virus (MEV), feline...... on inactivated virus. Surprisingly, this protection was obtained after only a single injection. Furthermore, the vaccinal dose of 150 μg of conjugated peptide or 3 μg of recombinant VP2 particles per animal, are sufficiently low to be cost-effective and applicable on a large scale....

  15. Vaccination with poly(IC:LC and peptide-pulsed autologous dendritic cells in patients with pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Shikhar Mehrotra

    2017-04-01

    Full Text Available Abstract Background Dendritic cells (DCs enhance the quality of anti-tumor immune response in patients with cancer. Thus, we posit that DC-based immunotherapy, in conjunction with toll-like receptor (TLR-3 agonist poly-ICLC, is a promising approach for harnessing immunity against metastatic or locally advanced unresectable pancreatic cancer (PC. Methods We generated autologous DCs from the peripheral blood of HLA-A2+ patients with PC. DCs were pulsed with three distinct A2-restricted peptides: 1 human telomerase reverse transcriptase (hTERT, TERT572Y, 2 carcinoembryonic antigen (CEA; Cap1-6D, and 3 survivin (SRV.A2. Patients received four intradermal injections of 1 × 107 peptide-pulsed DC vaccines every 2 weeks (Day 0, 14, 28, and 42. Concurrently, patients received intramuscular administration of Poly-ICLC at 30 μg/Kg on vaccination days (i.e., day 0, 14, 28, and 42, as well as on days 3, 17, 21, 31, 37, and 45. Our key objective was to assess safety and feasibility. The effect of DC vaccination on immune response was measured at each DC injection time point by enumerating the phenotype and function of patient T cells. Results Twelve patients underwent apheresis: nine patients with metastatic disease, and three patients with locally advanced unresectable disease. Vaccines were successfully manufactured from all individuals. We found that this treatment was well-tolerated, with the most common symptoms being fatigue and/or self-limiting flu-like symptoms. Among the eight patients who underwent imaging on day 56, four patients experienced stable disease while four patients had disease progression. The median overall survival was 7.7 months. One patient survived for 28 months post leukapheresis. MHC class I –tetramer analysis before and after vaccination revealed effective generation of antigen-specific T cells in three patients with stable disease. Conclusion Vaccination with peptide-pulsed DCs in combination with poly-ICLC is safe and

  16. Exosomes derived from tumor cells genetically modified to express Mycobacterium tuberculosis antigen: a novel vaccine for cancer therapy.

    Science.gov (United States)

    Koyama, Yoshiyuki; Ito, Tomoko; Hasegawa, Aya; Eriguchi, Masazumi; Inaba, Toshio; Ushigusa, Takahiro; Sugiura, Kikuya

    2016-11-01

    To examine the potential of exosomes derived from the tumor cells, which had been genetically modified to express a Mycobacterium tuberculosis antigen, as a cancer vaccine aimed at overcoming the weak immunogenicity of tumor antigens. We transfected B16 melanoma cells with a plasmid encoding the M. tuberculosis antigen, early secretory antigenic target-6 (ESAT-6). The secreted exosomes bearing both tumor-associated antigens and the pathogenic antigen (or their epitopes) were collected. When the exosomes were injected into foot pads of mice, they significantly (p exosomes significantly suppressed (p exosomes derived from the non-transfected B16 cells showed no effect on tumor growth, although both exosomes should have similar tumor antigens. Exosomes bearing both tumor antigens and the M. tuberculosis antigen (or their epitopes) have a high potential as a candidate for cancer vaccine to overcome the immune escape by tumor cells.

  17. Crystal structure of a TAPBPR–MHC I complex reveals the mechanism of peptide editing in antigen presentation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jiansheng; Natarajan, Kannan; Boyd, Lisa F.; Morozov, Giora I.; Mage, Michael G.; Margulies, David H. (NIH); (Hebrew)

    2017-10-12

    Central to CD8+ T cell–mediated immunity is the recognition of peptide–major histocompatibility complex class I (p–MHC I) proteins displayed by antigen-presenting cells. Chaperone-mediated loading of high-affinity peptides onto MHC I is a key step in the MHC I antigen presentation pathway. However, the structure of MHC I with a chaperone that facilitates peptide loading has not been determined. We report the crystal structure of MHC I in complex with the peptide editor TAPBPR (TAP-binding protein–related), a tapasin homolog. TAPBPR remodels the peptide-binding groove of MHC I, resulting in the release of low-affinity peptide. Changes include groove relaxation, modifications of key binding pockets, and domain adjustments. This structure captures a peptide-receptive state of MHC I and provides insights into the mechanism of peptide editing by TAPBPR and, by analogy, tapasin.

  18. A multi-antigenic MVA vaccine increases efficacy of combination chemotherapy against Mycobacterium tuberculosis.

    Science.gov (United States)

    Leung-Theung-Long, Stéphane; Coupet, Charles-Antoine; Gouanvic, Marie; Schmitt, Doris; Ray, Aurélie; Hoffmann, Chantal; Schultz, Huguette; Tyagi, Sandeep; Soni, Heena; Converse, Paul J; Arias, Lilibeth; Kleinpeter, Patricia; Sansas, Benoît; Mdluli, Khisimuzi; Vilaplana, Cristina; Cardona, Pere-Joan; Nuermberger, Eric; Marchand, Jean-Baptiste; Silvestre, Nathalie; Inchauspé, Geneviève

    2018-01-01

    Despite the existence of the prophylactic Bacille Calmette-Guérin (BCG) vaccine, infection by Mycobacterium tuberculosis (Mtb) remains a major public health issue causing up to 1.8 million annual deaths worldwide. Increasing prevalence of Mtb strains resistant to antibiotics represents an urgent threat for global health that has prompted a search for alternative treatment regimens not subject to development of resistance. Immunotherapy constitutes a promising approach to improving current antibiotic treatments through engagement of the host's immune system. We designed a multi-antigenic and multiphasic vaccine, based on the Modified Vaccinia Ankara (MVA) virus, denoted MVATG18598, which expresses ten antigens classically described as representative of each of different phases of Mtb infection. In vitro analysis coupled with multiple-passage evaluation demonstrated that this vaccine is genetically stable, i.e. fit for manufacturing. Using different mouse strains, we show that MVATG18598 vaccination results in both Th1-associated T-cell responses and cytolytic activity, targeting all 10 vaccine-expressed Mtb antigens. In chronic post-exposure mouse models, MVATG18598 vaccination in combination with an antibiotic regimen decreases the bacterial burden in the lungs of infected mice, compared with chemotherapy alone, and is associated with long-lasting antigen-specific Th1-type T cell and antibody responses. In one model, co-treatment with MVATG18598 prevented relapse of the disease after treatment completion, an important clinical goal. Overall, results demonstrate the capacity of the therapeutic MVATG18598 vaccine to improve efficacy of chemotherapy against TB. These data support further development of this novel immunotherapeutic in the treatment of Mtb infections.

  19. A multi-antigenic MVA vaccine increases efficacy of combination chemotherapy against Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Stéphane Leung-Theung-Long

    Full Text Available Despite the existence of the prophylactic Bacille Calmette-Guérin (BCG vaccine, infection by Mycobacterium tuberculosis (Mtb remains a major public health issue causing up to 1.8 million annual deaths worldwide. Increasing prevalence of Mtb strains resistant to antibiotics represents an urgent threat for global health that has prompted a search for alternative treatment regimens not subject to development of resistance. Immunotherapy constitutes a promising approach to improving current antibiotic treatments through engagement of the host's immune system. We designed a multi-antigenic and multiphasic vaccine, based on the Modified Vaccinia Ankara (MVA virus, denoted MVATG18598, which expresses ten antigens classically described as representative of each of different phases of Mtb infection. In vitro analysis coupled with multiple-passage evaluation demonstrated that this vaccine is genetically stable, i.e. fit for manufacturing. Using different mouse strains, we show that MVATG18598 vaccination results in both Th1-associated T-cell responses and cytolytic activity, targeting all 10 vaccine-expressed Mtb antigens. In chronic post-exposure mouse models, MVATG18598 vaccination in combination with an antibiotic regimen decreases the bacterial burden in the lungs of infected mice, compared with chemotherapy alone, and is associated with long-lasting antigen-specific Th1-type T cell and antibody responses. In one model, co-treatment with MVATG18598 prevented relapse of the disease after treatment completion, an important clinical goal. Overall, results demonstrate the capacity of the therapeutic MVATG18598 vaccine to improve efficacy of chemotherapy against TB. These data support further development of this novel immunotherapeutic in the treatment of Mtb infections.

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

    NARCIS (Netherlands)

    Vermeij, R.; Daemen, T.; de Bock, G.H.; de Graeff, P.; Leffers, N.; Lambeck, A.; Ten Hoor, K.A.; Hollema, H.; van der Zee, A.G.J.; Nijman, H.W.

    2010-01-01

    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

  2. Antigenicity and immunogenicity of a novel Plasmodium vivax circumsporozoite derived synthetic vaccine construct

    DEFF Research Database (Denmark)

    Céspedes, Nora; Jiménez, Eliécer; Lopez-Perez, Mary

    2014-01-01

    BACKGROUND: The circumsporozoite (CS) protein is a major malaria sporozoite surface antigen currently being considered as vaccine candidate. Plasmodium vivax CS (PvCS) protein comprises a dimorphic central repeat fragment flanked by conserved regions that contain functional domains involved in pa...

  3. Comparative immunological evaluation of recombinant Salmonella Typhimurium strains expressing model antigens as live oral vaccines.

    Science.gov (United States)

    Zheng, Song-yue; Yu, Bin; Zhang, Ke; Chen, Min; Hua, Yan-Hong; Yuan, Shuofeng; Watt, Rory M; Zheng, Bo-Jian; Yuen, Kwok-Yung; Huang, Jian-Dong

    2012-09-26

    Despite the development of various systems to generate live recombinant Salmonella Typhimurium vaccine strains, little work has been performed to systematically evaluate and compare their relative immunogenicity. Such information would provide invaluable guidance for the future rational design of live recombinant Salmonella oral vaccines. To compare vaccine strains encoded with different antigen delivery and expression strategies, a series of recombinant Salmonella Typhimurium strains were constructed that expressed either the enhanced green fluorescent protein (EGFP) or a fragment of the hemagglutinin (HA) protein from the H5N1 influenza virus, as model antigens. The antigens were expressed from the chromosome, from high or low-copy plasmids, or encoded on a eukaryotic expression plasmid. Antigens were targeted for expression in either the cytoplasm or the outer membrane. Combinations of strategies were employed to evaluate the efficacy of combined delivery/expression approaches. After investigating in vitro and in vivo antigen expression, growth and infection abilities; the immunogenicity of the constructed recombinant Salmonella strains was evaluated in mice. Using the soluble model antigen EGFP, our results indicated that vaccine strains with high and stable antigen expression exhibited high B cell responses, whilst eukaryotic expression or colonization with good construct stability was critical for T cell responses. For the insoluble model antigen HA, an outer membrane expression strategy induced better B cell and T cell responses than a cytoplasmic strategy. Most notably, the combination of two different expression strategies did not increase the immune response elicited. Through systematically evaluating and comparing the immunogenicity of the constructed recombinant Salmonella strains in mice, we identified their respective advantages and deleterious or synergistic effects. Different construction strategies were optimally-required for soluble versus

  4. Australian contingency plans for emergency animal disease control: the role of antigen/vaccine banks.

    Science.gov (United States)

    Tweddle, N E

    2004-01-01

    Vaccination is an important element of contingency plans for many animal diseases. The decision whether or not to use vaccine is complex, and must consider epidemiological, economic and social issues. Vaccines are rarely available in a country for emergency animal diseases unless a low pathogenicity strain of the agent is present or it is localised in carrier hosts. High quality commercial vaccine from overseas is often the preferred source of vaccine in an emergency, although less reliable sources may be used with additional safeguards. Alternatively, master seeds may be imported or developed for production within the country For contingency planning, diseases may be ranked according to the expected role of vaccine in the disease eradication strategy, with diseases for which vaccine is part of the initial response strategy receiving highest priority for action. A range of preparedness options is available, ranging from identifying producers of vaccine, obtaining permits for import and use from regulatory authorities, to establishing vaccine or antigen banks. Countries need to consider their individual situations and develop strategies to address the diseases of significance to them.

  5. The Peptide Vaccine Combined with Prior Immunization of a Conventional Diphtheria-Tetanus Toxoid Vaccine Induced Amyloid β Binding Antibodies on Cynomolgus Monkeys and Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Akira Yano

    2015-01-01

    Full Text Available The reduction of brain amyloid beta (Aβ peptides by anti-Aβ antibodies is one of the possible therapies for Alzheimer’s disease. We previously reported that the Aβ peptide vaccine including the T-cell epitope of diphtheria-tetanus combined toxoid (DT induced anti-Aβ antibodies, and the prior immunization with conventional DT vaccine enhanced the immunogenicity of the peptide. Cynomolgus monkeys were given the peptide vaccine subcutaneously in combination with the prior DT vaccination. Vaccination with a similar regimen was also performed on guinea pigs. The peptide vaccine induced anti-Aβ antibodies in cynomolgus monkeys and guinea pigs without chemical adjuvants, and excessive immune responses were not observed. Those antibodies could preferentially recognize Aβ40, and Aβ42 compared to Aβ fibrils. The levels of serum anti-Aβ antibodies and plasma Aβ peptides increased in both animals and decreased the brain Aβ40 level of guinea pigs. The peptide vaccine could induce a similar binding profile of anti-Aβ antibodies in cynomolgus monkeys and guinea pigs. The peptide vaccination could be expected to reduce the brain Aβ peptides and their toxic effects via clearance of Aβ peptides by generated antibodies.

  6. Chimeric vaccine composed of viral peptide and mammalian heat-shock protein 60 peptide protects against West Nile virus challenge.

    Science.gov (United States)

    Gershoni-Yahalom, Orly; Landes, Shimon; Kleiman-Shoval, Smadar; Ben-Nathan, David; Kam, Michal; Lachmi, Bat-El; Khinich, Yevgeny; Simanov, Michael; Samina, Itzhak; Eitan, Anat; Cohen, Irun R; Rager-Zisman, Bracha; Porgador, Angel

    2010-08-01

    The protective efficacy and immunogenicity of a chimeric peptide against West Nile virus (WNV) was evaluated. This virus is the aetiological agent of West Nile fever, which has recently emerged in the western hemisphere. The rapid spread of WNV throughout North America, as well as the constantly changing epidemiology and transmission of the virus by blood transfusion and transplantation, have raised major public-health concerns. Currently, there are no effective treatments for WNV or vaccine for human use. We previously identified a novel, continuous B-cell epitope from domain III of the WNV envelope protein, termed Ep15. To test whether this epitope can protect against WNV infection, we synthesized a linear chimeric peptide composed of Ep15 and the heat-shock protein 60 peptide, p458. The p458 peptide is an effective carrier peptide for subunit vaccines against other infectious agents. We now report that mice immunized with the chimeric peptide, p458-Ep15, were resistant to lethal challenges with three different WNV strains. Moreover, their brains were free of viral genome and infectious virus. Mice immunized with Ep15 alone or with p431-Ep15, a control conjugate, were not protected. The chimeric p458-Ep15 peptide induced WNV-specific immunoglobulin G antibodies that neutralized the virus and induced the secretion of interferon-gammain vitro. Challenge of chimeric peptide-immunized mice considerably enhanced WNV-specific neutralizing antibodies. We conclude that this chimeric peptide can be used for formulation of a human vaccine against WNV.

  7. Directed antigen delivery as a vaccine strategy for an intracellular bacterial pathogen

    Science.gov (United States)

    Bouwer, H. G. Archie; Alberti-Segui, Christine; Montfort, Megan J.; Berkowitz, Nathan D.; Higgins, Darren E.

    2006-03-01

    We have developed a vaccine strategy for generating an attenuated strain of an intracellular bacterial pathogen that, after uptake by professional antigen-presenting cells, does not replicate intracellularly and is readily killed. However, after degradation of the vaccine strain within the phagolysosome, target antigens are released into the cytosol for endogenous processing and presentation for stimulation of CD8+ effector T cells. Applying this strategy to the model intracellular pathogen Listeria monocytogenes, we show that an intracellular replication-deficient vaccine strain is cleared rapidly in normal and immunocompromised animals, yet antigen-specific CD8+ effector T cells are stimulated after immunization. Furthermore, animals immunized with the intracellular replication-deficient vaccine strain are resistant to lethal challenge with a virulent WT strain of L. monocytogenes. These studies suggest a general strategy for developing safe and effective, attenuated intracellular replication-deficient vaccine strains for stimulation of protective immune responses against intracellular bacterial pathogens. CD8+ T cell | replication-deficient | Listeria monocytogenes

  8. Conservation analysis of dengue virust-cell epitope-based vaccine candidates using peptide block entropy

    DEFF Research Database (Denmark)

    Olsen, Lars Rønn; Zhang, Guang Lan; Keskin, Derin B.

    2011-01-01

    residues. The block entropy analysis provides broad coverage of variant antigens. We applied the block entropy analysis method to the proteomes of the four serotypes of dengue virus (DENV) and found 1,551 blocks of 9-mer peptides, which cover 99% of available sequences with five or fewer unique peptides...

  9. Active self-healing encapsulation of vaccine antigens in PLGA microspheres

    Science.gov (United States)

    Desai, Kashappa-Goud H.; Schwendeman, Steven P.

    2013-01-01

    Herein, we describe the detailed development of a simple and effective method to microencapsulate vaccine antigens in poly(lactic-co-glycolic acid) (PLGA) by simple mixing of preformed active self-microencapsulating (SM) PLGA microspheres in a low concentration aqueous antigen solution at modest temperature (10-38 °C). Co-encapsulating protein-sorbing vaccine adjuvants and polymer plasticizers were used to “actively” load the protein in the polymer pores and facilitate polymer self-healing at temperature > hydrated polymer glass transition temperature, respectively. The microsphere formulation parameters and loading conditions to provide optimal active self-healing microencapsulation of vaccine antigen in PLGA was investigated. Active self-healing encapsulation of two vaccine antigens, ovalbumin and tetanus toxoid (TT), in PLGA microspheres was adjusted by preparing blank microspheres containing different vaccine adjuvant (aluminum hydroxide (Al(OH)3) or calcium phosphate). Active loading of vaccine antigen in Al(OH)3-PLGA microspheres was found to: a) increase proportionally with an increasing loading of Al(OH)3 (0.88-3 wt%) and addition of porosigen, b) decrease when the inner Al(OH)3/trehalose phase to 1 mL outer oil phase and size of microspheres was respectively > 0.2 mL and 63 μm, and c) change negligibly by PLGA concentration and initial incubation (loading) temperature. Encapsulation of protein sorbing Al(OH)3 in PLGA microspheres resulted in suppression of self-healing of PLGA pores, which was then overcome by improving polymer chain mobility, which in turn was accomplished by coincorporating hydrophobic plasticizers in PLGA. Active self-healing microencapsulation of manufacturing process-labile TT in PLGA was found to: a) obviate micronization- and organic solvent-induced TT degradation, b) improve antigen loading (1.4-1.8 wt% TT) and encapsulation efficiency (~ 97%), c) provide nearly homogeneous distribution and stabilization of antigen in polymer

  10. GM-CSF production allows the identification of immunoprevalent antigens recognized by human CD4+ T cells following smallpox vaccination.

    Directory of Open Access Journals (Sweden)

    Valeria Judkowski

    Full Text Available The threat of bioterrorism with smallpox and the broad use of vaccinia vectors for other vaccines have led to the resurgence in the study of vaccinia immunological memory. The importance of the role of CD4+ T cells in the control of vaccinia infection is well known. However, more CD8+ than CD4+ T cell epitopes recognized by human subjects immunized with vaccinia virus have been reported. This could be, in part, due to the fact that most of the studies that have identified human CD4+ specific protein-derived fragments or peptides have used IFN-γ production to evaluate vaccinia specific T cell responses. Based on these findings, we reasoned that analyzing a large panel of cytokines would permit us to generate a more complete analysis of the CD4 T cell responses. The results presented provide clear evidence that TNF-α is an excellent readout of vaccinia specificity and that other cytokines such as GM-CSF can be used to evaluate the reactivity of CD4+ T cells in response to vaccinia antigens. Furthermore, using these cytokines as readout of vaccinia specificity, we present the identification of novel peptides from immunoprevalent vaccinia proteins recognized by CD4+ T cells derived from smallpox vaccinated human subjects. In conclusion, we describe a "T cell-driven" methodology that can be implemented to determine the specificity of the T cell response upon vaccination or infection. Together, the single pathogen in vitro stimulation, the selection of CD4+ T cells specific to the pathogen by limiting dilution, the evaluation of pathogen specificity by detecting multiple cytokines, and the screening of the clones with synthetic combinatorial libraries, constitutes a novel and valuable approach for the elucidation of human CD4+ T cell specificity in response to large pathogens.

  11. Comparison of vaccine efficacy for different antigen delivery systems for infectious pancreatic necrosis virus vaccines in Atlantic salmon (Salmo salar L.) in a cohabitation challenge model.

    Science.gov (United States)

    Munang'andu, Hetron M; Fredriksen, Børge N; Mutoloki, Stephen; Brudeseth, Bjørn; Kuo, Tsun-Yung; Marjara, Inderjit S; Dalmo, Roy A; Evensen, Øystein

    2012-06-08

    Two strains of IPNV made by reverse genetics on the Norwegian Sp strain NVI-015 (GenBank AY379740) backbone encoding the virulent (T(217)A(221)) and avirulent (P(217)T(221)) motifs were used to prepare inactivated whole virus (IWV), nanoparticle vaccines with whole virus, Escherichia coli subunit encoding truncated VP2-TA and VP2-PT, VP2-TA and VP2-PT fusion antigens with putative translocating domains of Pseudomonas aeruginosa exotoxin, and plasmid DNA encoding segment A of the TA strain. Post challenge survival percentages (PCSP) showed that IWV vaccines conferred highest protection (PCSP=42-53) while nanoparticle, sub-unit recombinant and DNA vaccines fell short of the IWV vaccines in Atlantic salmon (Salmo salar L.) postsmolts challenged with the highly virulent Sp strain NVI-015 (TA strain) of IPNV after 560 degree days post vaccination. Antibody levels induced by these vaccines did not show antigenic differences between the virulent and avirulent motifs for vaccines made with the same antigen dose and delivery system after 8 weeks post vaccination. Our findings show that fish vaccinated with less potent vaccines comprising of nanoparticle, DNA and recombinant vaccines got infected much earlier and yielded to higher infection rates than fish vaccinated with IWV vaccines that were highly potent. Ability of the virulent (T(217)A(221)) and avirulent (P(217)T(221)) motifs to limit establishment of infection showed equal protection for vaccines made of the same antigen dose and delivery systems. Prevention of tissue damage linked to viral infection was eminent in the more potent vaccines than the less protective ones. Hence, there still remains the challenge of developing highly efficacious vaccines with the ability to eliminate the post challenge carrier state in IPNV vaccinology. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Peptides in melanoma therapy.

    Science.gov (United States)

    Mocellin, Simone

    2012-01-01

    Peptides derived from tumor associated antigens can be utilized to elicit a therapeutically effective immune response against melanoma in experimental models. However, patient vaccination with peptides - although it is often followed by the induction of melanoma- specific T lymphocytes - is rarely associated with tumor response of clinical relevance. In this review I summarize the principles of peptide design as well as the results so far obtained in the clinical setting while treating cutaneous melanoma by means of this active immunotherapy strategy. I also discuss some immunological and methodological issues that might be helpful for the successful development of peptide-based vaccines.

  13. 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.

  14. 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

    2002-01-01

    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 statistic......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 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 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....

  15. Genetic distribution of noncapsular meningococcal group B vaccine antigens in Neisseria lactamica.

    Science.gov (United States)

    Lucidarme, Jay; Gilchrist, Stefanie; Newbold, Lynne S; Gray, Stephen J; Kaczmarski, Edward B; Richardson, Lynne; Bennett, Julia S; Maiden, Martin C J; Findlow, Jamie; Borrow, Ray

    2013-09-01

    The poor immunogenicity of the meningococcal serogroup B (MenB) capsule has led to the development of vaccines targeting subcapsular antigens, in particular the immunodominant and diverse outer membrane porin, PorA. These vaccines are largely strain specific; however, they offer limited protection against the diverse MenB-associated diseases observed in many industrialized nations. To broaden the scope of its protection, the multicomponent vaccine (4CMenB) incorporates a PorA-containing outer membrane vesicle (OMV) alongside relatively conserved recombinant protein components, including factor H-binding protein (fHbp), Neisseria adhesin A (NadA), and neisserial heparin-binding antigen (NHBA). The expression of PorA is unique to meningococci (Neisseria meningitidis); however, many subcapsular antigens are shared with nonpathogenic members of the genus Neisseria that also inhabit the nasopharynx. These organisms may elicit cross-protective immunity against meningococci and/or occupy a niche that might otherwise accommodate pathogens. The potential for 4CMenB responses to impact such species (and vice versa) was investigated by determining the genetic distribution of the primary 4CMenB antigens among diverse members of the common childhood commensal, Neisseria lactamica. All the isolates possessed nhba but were devoid of fhbp and nadA. The nhba alleles were mainly distinct from but closely related to those observed among a representative panel of invasive MenB isolates from the same broad geographic region. We made similar findings for the immunogenic typing antigen, FetA, which constitutes a major part of the 4CMenB OMV. Thus, 4CMenB vaccine responses may impact or be impacted by nasopharyngeal carriage of commensal neisseriae. This highlights an area for further research and surveillance should the vaccine be routinely implemented.

  16. Thermostability of the coating, antigen and immunostimulator in an adjuvanted oral capsule vaccine formulation.

    Science.gov (United States)

    Longet, Stephanie; Aversa, Vincenzo; O'Donnell, Daire; Tobias, Joshua; Rosa, Monica; Holmgren, Jan; Coulter, Ivan S; Lavelle, Ed C

    2017-12-20

    Oral vaccines present an attractive alternative to injectable vaccines for enteric diseases due to ease of delivery and the induction of intestinal immunity at the site of infection. However, susceptibility to gastrointestinal proteolysis, limited transepithelial uptake and a lack of clinically acceptable adjuvants present significant challenges. A further challenge to mass vaccination in developing countries is the very expensive requirement to maintain the cold chain. We recently described the effectiveness of a Single Multiple Pill ® (SmPill ® ) adjuvanted capsule approach to enhance the effectiveness of a candidate enterotoxigenic Escherichia coli (ETEC) oral vaccine. Here it was demonstrated that this delivery system maintains the antigenicity of ETEC colonisation factor antigen I (CFA/I) and the immunostimulatory activity of the orally active α-Galactosylceramide (α-GalCer) adjuvant after storage of SmPill ® minispheres under room temperature and extreme storage conditions for several months. In addition, the internal structure of the cores of SmPill ® minispheres and antigen release features at intestinal pH were found to be preserved under all these conditions. However, changes in the surface morphology of SmPill ® minispheres leading to the antigen release at gastric pH were observed after a few weeks of storage under extreme conditions. Those modifications were prevented by the introduction of an Opadry ® White film coating layer between the core of SmPill ® minispheres and the enteric coating. Under these conditions, protection against antigen release at gastric pH was maintained even under high temperature and humidity conditions. These results support the potential of the SmPill ® minisphere approach to maintain the stability of an adjuvanted whole cell killed oral vaccine formulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. 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.

  18. Antigen-Specific lgA B Memory Cell Responses to Shigella Antigens Elicited in Volunteers Immunized with Live Attenuated Shigella flexneri 2a Oral Vaccine Candidates

    Science.gov (United States)

    2011-01-01

    167. [10] E.V. Oaks, T.L. Hale, S.B. Formal, Serum immune response to Shigella protein antigens in rhesus monkeys and humans infected with Shigella ...cell responses to Shigella antigens elicited in volunteers immunized with live attenuated Shigella flexneri 2a oral vaccine candidates J.K. Simona,b... Shigella ;. B cell memory; Immunoglobulin lgA; Mucosal immunity Abstract We studied the induction of antigen-specific lgA memory B cells (BM) in

  19. Cancer-germline antigen vaccines and epigenetic enhancers

    DEFF Research Database (Denmark)

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

    2010-01-01

    IMPORTANCE OF THE FIELD: Immunotherapy holds great potential for disseminated cancer, and cancer-germline (CG) antigens are among the most promising tumor targets. They are widely expressed in different cancer types and are essentially tumor-specific, since their expression in normal tissues is l...

  20. 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.

  1. Competitor analogs for defined T cell antigens: peptides incorporating a putative binding motif and polyproline or polyglycine spacers.

    Science.gov (United States)

    Maryanski, J L; Verdini, A S; Weber, P C; Salemme, F R; Corradin, G

    1990-01-12

    We describe a new approach for modeling antigenic peptides recognized by T cells. Peptide A24 170-182 can compete with other antigenic peptides that are recognized by H-2kd-restricted cytolytic T cells, presumably by binding to the Kd molecule. By comparing substituted A24 peptides as competitors in a functional competition assay, the A24 residues Tyr-171, Thr-178, and Leu-179 were identified as possible contact residues for Kd. A highly active competitor peptide analog was synthesized in which Tyr was separated from the Thr-Leu pair by a pentaproline spacer. The choice of proline allowed the prediction of a probable conformation for the analog when bound to the Kd molecule. The simplest conformation of the A24 peptide that allows the same spacing and orientation of the motif as in the analog would be a nearly extended polypeptide chain incorporating a single 3(10) helical turn or similar structural kink.

  2. Protein antigenic structures recognized by T cells: potential applications to vaccine design.

    Science.gov (United States)

    Berzofsky, J A; Cease, K B; Cornette, J L; Spouge, J L; Margalit, H; Berkower, I J; Good, M F; Miller, L H; DeLisi, C

    1987-08-01

    In summary, our results using the model protein antigen myoglobin indicated, in concordance with others, that helper T lymphocytes recognize a limited number of immunodominant antigenic sites of any given protein. Such immunodominant sites are the focus of a polyclonal response of a number of different T cells specific for distinct but overlapping epitopes. Therefore, the immunodominance does not depend on the fine specificity of any given clone of T cells, but rather on other factors, either intrinsic or extrinsic to the structure of the antigen. A major extrinsic factor is the MHC of the responding individual, probably due to a requirement for the immunodominant peptides to bind to the MHC of presenting cells in that individual. In looking for intrinsic factors, we noted that both immunodominant sites of myoglobin were amphipathic helices, i.e., helices having hydrophilic and hydrophobic residues on opposite sides. Studies with synthetic peptides indicated that residues on the hydrophilic side were necessary for T-cell recognition. However, unfolding of the native protein was shown to be the apparent goal of processing of antigen, presumably to expose something not already exposed on the native molecule, such as the hydrophobic sides of these helices. We propose that such exposure is necessary to interact with something on the presenting cell, such as MHC or membrane, where we have demonstrated the presence of antigenic peptides by blocking of presentation of biotinylated peptide with avidin. The membrane may serve as a short-term memory of peptides from antigens encountered by the presenting cell, for dynamic sampling by MHC molecules to be available for presentation to T cells. These ideas, together with the knowledge that T-cell recognition required only short peptides and therefore had to be based only on primary or secondary structure, not tertiary folding of the native protein, led us to propose that T-cell immunodominant epitopes may tend to be amphipathic

  3. Lipopolysaccharide Antigens of Pseudomonas aeruginosa and Design of Novel Vaccines.

    Science.gov (United States)

    1987-09-01

    Studies on the Lipopolysaccharide Antigens of Seven Immunotypes of P a_ n , SELAQ, Proc. 3 VL Seminario Latinoamericano J1 Quimica , pp. 143-159 (1979). 7...Bioolymers, 19 (1980) 1801-1814. 74" , 8. Derek Horton and David A. Riley, Phosphorus-31 Nuclear Magnetic Resonance Spectroscopy of Lipopolysaccharides...Amer. Chem. Soc., 87 (1965), 1345-1353. 40. D. Horton and D. A. Riley, "Phosphorus-31 Nuclear Magnetic Resonance Spectroscopy of Lipopolysaccharides

  4. Phase I clinical trial of the vaccination for the patients with metastatic melanoma using gp100-derived epitope peptide restricted to HLA-A*2402

    Directory of Open Access Journals (Sweden)

    Baba Toshiyuki

    2010-09-01

    Full Text Available Abstract Background The tumor associated antigen (TAA gp100 was one of the first identified and has been used in clinical trials to treat melanoma patients. However, the gp100 epitope peptide restricted to HLA-A*2402 has not been extensively examined clinically due to the ethnic variations. Since it is the most common HLA Class I allele in the Japanese population, we performed a phase I clinical trial of cancer vaccination using the HLA-A*2402 gp100 peptide to treat patients with metastatic melanoma. Methods The phase I clinical protocol to test a HLA-A*2402 gp100 peptide-based cancer vaccine was designed to evaluate safety as the primary endpoint and was approved by The University of Tokyo Institutional Review Board. Information related to the immunologic and antitumor responses were also collected as secondary endpoints. Patients that were HLA-A*2402 positive with stage IV melanoma were enrolled according to the criteria set by the protocol and immunized with a vaccine consisting of epitope peptide (VYFFLPDHL, gp100-in4 emulsified with incomplete Freund's adjuvant (IFA for the total of 4 times with two week intervals. Prior to each vaccination, peripheral blood mononuclear cells (PBMCs were separated from the blood and stored at -80°C. The stored PBMCs were thawed and examined for the frequency of the peptide specific T lymphocytes by IFN-γ- ELISPOT and MHC-Dextramer assays. Results No related adverse events greater than grade I were observed in the six patients enrolled in this study. No clinical responses were observed in the enrolled patients although vitiligo was observed after the vaccination in two patients. Promotion of peptide specific immune responses was observed in four patients with ELISPOT assay. Furthermore, a significant increase of CD8+ gp100-in4+ CTLs was observed in all patients using the MHC-Dextramer assay. Cytotoxic T lymphocytes (CTLs clones specific to gp100-in4 were successfully established from the PBMC of some

  5. Immunogenicity of DNA vaccines encoding simian immunodeficiency virus antigen targeted to dendritic cells in rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Matthias Tenbusch

    Full Text Available BACKGROUND: Targeting antigens encoded by DNA vaccines to dendritic cells (DCs in the presence of adjuvants enhances their immunogenicity and efficacy in mice. METHODOLOGY/PRINCIPAL FINDINGS: To explore the immunogenicity of this approach in non-human primates, we generated a single chain antibody to the antigen uptake receptor DEC-205 expressed on rhesus macaque DCs. DNA vaccines encoding this single chain antibody fused to the SIV capsid protein were delivered to six monkeys each by either intramuscular electroporation or conventional intramuscular injection co-injected or not with poly ICLC, a stabilized poly I: C analogue, as adjuvant. Antibodies to capsid were induced by the DC-targeting and non-targeting control DNA delivered by electroporation while conventional DNA immunization at a 10-fold higher dose of DNA failed to induce detectable humoral immune responses. Substantial cellular immune responses were also observed after DNA electroporation of both DNAs, but stronger responses were induced by the non-targeting vaccine. Conventional immunization with the DC-targeting DNA at a 10-fold higher dose did not give rise to substantial cellular immune responses, neither when co-injected with poly ICLC. CONCLUSIONS/SIGNIFICANCE: The study confirms the potent immunogenicity of DNA vaccines delivered by electroporation. Targeting the DNA via a single chain antibody to DEC-205 expressed by DCs, however, does not improve the immunogenicity of the antigens in non-human primates.

  6. Isolation of a peptide binding protein and its role in antigen presentation

    International Nuclear Information System (INIS)

    Lakey, E.; Pierce, S.K.; Margoliash, E.

    1986-01-01

    A mouse T cell hybrid, TPc9.1, recognizes pigeon cytochrome c (Pc) as processed and presented by histocompatible antigen presenting cells (APC). When paraformaldehyde fixed APC are employed, only a peptide fragment of Pc, Pc 81-104, and not the native Pc, is capable of stimulating TPc9.1 cells. Pc 81-104 appears to associate tightly with the APC surface since paraformaldehyde fixed APC which have been incubated with Pc 81-104 remain stimulatory following extensive washing. When APC are surface labeled with 125 I, solubilized and affinity purified on Pc 81-104-Sepharose 4B columns, two predominant polypeptides of approximately 72 and 74 kd are isolated. Little or no immunoglobulin, Class I or Class II proteins are obtained under these conditions. Antisera from rabbits immunized with the affinity purified material, but not preimmune sera, block the activation of TPc 9.1 cells by Pc as well as Pc 81-104 when presented by live APC. Furthermore, these antisera are even more effective in blocking the activation of TPc9.1 cells by either APC which had been pulsed with Pc and then paraformaldehyde fixed, or by Pc 81-104 when added to paraformaldehyde fixed APC, suggesting that these antisera were not affecting antigen processing. Thus, these peptide binding proteins may play a role in antigen presentation, and they are being further characterized

  7. Combinatorial synthetic peptide vaccine strategy protects against hypervirulent CovR/S mutant streptococci

    DEFF Research Database (Denmark)

    Pandey, Manisha; Mortensen, Rasmus; Calcutt, Ainslie

    2016-01-01

    -mediated killing and enabling ingress of bacteria from a superficial wound to deep tissue.We previously showed that a combination vaccine incorporating J8-DT (conserved peptide vaccine from theM protein) and a recombinant SpyCEP fragment protects against CovR/S mutants. To enhance the vaccine's safety profile, we......), and it would be to the organism's advantage if the host did not induce a strong Ab response against it. However, S2 conjugated to diphtheria toxoid is highly immunogenic and induces Abs that recognize and neutralize SpyCEP. Hence, we describe a two-component peptide vaccine that induces Abs (anti-S2....... This protection correlated with a significant influx of neutrophils to the infection site. The data strongly suggest that the lack of natural immunity to hypervirulent GAS strains in humans could be rectified by this combination vaccine....

  8. 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-conserved......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...

  9. Immunogenicity and safety of a tetravalent E. coli O-antigen bioconjugate vaccine in animal models.

    Science.gov (United States)

    van den Dobbelsteen, Germie P J M; Faé, Kellen C; Serroyen, Jan; van den Nieuwenhof, Ingrid M; Braun, Martin; Haeuptle, Micha A; Sirena, Dominique; Schneider, Joerg; Alaimo, Cristina; Lipowsky, Gerd; Gambillara-Fonck, Veronica; Wacker, Michael; Poolman, Jan T

    2016-07-29

    Extra-intestinal pathogenic Escherichia coli (ExPEC) are major human pathogens; however, no protective vaccine is currently available. We assessed in animal models the immunogenicity and safety of a 4-valent E. coli conjugate vaccine (ExPEC-4V, serotypes O1, O2, O6 and O25 conjugated to Exotoxin A from Pseudomonas aeruginosa (EPA)) produced using a novel in vivo bioconjugation method. Three doses of ExPEC-4V (with or without aluminum hydroxide) were administered to rabbits (2μg or 20μg per O-antigen, subcutaneously), mice (0.2μg or 2μg per O-antigen, subcutaneously) and rats (0.4μg or 4μg per O-antigen, intramuscularly). Antibody persistence and boostability were evaluated in rats using O6-EPA monovalent conjugate (0.4μg O-antigen/dose, intramuscularly). Toxicity was assessed in rats (16μg total polysaccharide, intramuscularly). Serum IgG and IgM antibodies were measured by ELISA. Robust antigen-specific IgG responses were observed in all animal models, with increased responses in rabbits when administered with adjuvant. O antigen-specific antibody responses persisted up to 168days post-priming. Booster immunization induced a rapid recall response. Toxicity of ExPEC-4V when administered to rats was considered to be at the no observed adverse effect level. ExPEC-4V conjugate vaccine showed good immunogenicity and tolerability in animal models supporting progression to clinical evaluation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Nod2 is required for antigen-specific humoral responses against antigens orally delivered using a recombinant Lactobacillus vaccine platform.

    Directory of Open Access Journals (Sweden)

    Sara A Bumgardner

    Full Text Available Safe and efficacious orally-delivered mucosal vaccine platforms are desperately needed to combat the plethora of mucosally transmitted pathogens. Lactobacillus spp. have emerged as attractive candidates to meet this need and are known to activate the host innate immune response in a species- and strain-specific manner. For selected bacterial isolates and mutants, we investigated the role of key innate immune pathways required for induction of innate and subsequent adaptive immune responses. Co-culture of murine macrophages with L. gasseri (strain NCK1785, L. acidophilus (strain NCFM, or NCFM-derived mutants-NCK2025 and NCK2031-elicited an M2b-like phenotype associated with TH2 skewing and immune regulatory function. For NCFM, this M2b phenotype was dependent on expression of lipoteichoic acid and S layer proteins. Through the use of macrophage genetic knockouts, we identified Toll-like receptor 2 (TLR2, the cytosolic nucleotide-binding oligomerization domain containing 2 (NOD2 receptor, and the inflammasome-associated caspase-1 as contributors to macrophage activation, with NOD2 cooperating with caspase-1 to induce inflammasome derived interleukin (IL-1β in a pyroptosis-independent fashion. Finally, utilizing an NCFM-based mucosal vaccine platform with surface expression of human immunodeficiency virus type 1 (HIV-1 Gag or membrane proximal external region (MPER, we demonstrated that NOD2 signaling is required for antigen-specific mucosal and systemic humoral responses. We show that lactobacilli differentially utilize innate immune pathways and highlight NOD2 as a key mediator of macrophage function and antigen-specific humoral responses to a Lactobacillus acidophilus mucosal vaccine platform.

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

    International Nuclear Information System (INIS)

    Kumar, Shantanu; Ochoa, Wendy; Singh, Pratik; Hsu, Catherine; Schneemann, Anette; Manchester, Marianne; Olson, Mark; Reddy, Vijay

    2009-01-01

    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.

  12. Identification of DLD, by immunoproteomic analysis and evaluation as a potential vaccine antigen against three Vibrio species in Epinephelus coioides.

    Science.gov (United States)

    Pang, Huanying; Chen, Liming; Hoare, Rowena; Huang, Yucong; ZaoheWu; Jian, Jichang

    2016-02-24

    Vibrio spp. represent a serious threat to the culture of Epinephelus coioides (Orange-spotted Grouper) in Southeast Asia. In this study we used two-dimensional electrophoresis (2-DE) and Western blotting to identify common immunogenic proteins of Vibrio alginolyticus, Vibrio harveyi and Vibrio parahaemolyticus. Membranes were probed with orange-spotted grouper anti-V. alginolyticus sera and accordingly 60, 58 and 48 immunogenic protein spots were detected. By matching analysis for the three Western blotting membranes, 6 cross immunogenic spots for the three Vibrio species were identified. They were Outer membrane protein W (OmpW), dihydrolipoamide dehydrogenase (DLD), succinate dehydrogenase flavoprotein subunit(SDHA), elongation factor Ts(Ts), peptide ABC transporter periplasmic peptide-binding protein and phosphoenolpyruvate carboxykinase(PEPCK). One of the proteins, DLD, was used to evaluate the cross protective function for E. coioides with a bacterial immunization and challenge method. The relative percent survival rate of E. coioides against V. alginolyticus, V. harveyi and V. parahaemolyticus was 90%, 86% and 80%, respectively. This work may provide potential cross protective vaccine candidate antigens for three Vibrio species, and DLD may be considered as an effective cross-protective immunogen against three Vibrio species. Copyright © 2016. Published by Elsevier Ltd.

  13. Applying the Concept of Peptide Uniqueness to Anti-Polio Vaccination

    Directory of Open Access Journals (Sweden)

    Darja Kanduc

    2015-01-01

    Full Text Available Background. Although rare, adverse events may associate with anti-poliovirus vaccination thus possibly hampering global polio eradication worldwide. Objective. To design peptide-based anti-polio vaccines exempt from potential cross-reactivity risks and possibly able to reduce rare potential adverse events such as the postvaccine paralytic poliomyelitis due to the tendency of the poliovirus genome to mutate. Methods. Proteins from poliovirus type 1, strain Mahoney, were analyzed for amino acid sequence identity to the human proteome at the pentapeptide level, searching for sequences that (1 have zero percent of identity to human proteins, (2 are potentially endowed with an immunologic potential, and (3 are highly conserved among poliovirus strains. Results. Sequence analyses produced a set of consensus epitopic peptides potentially able to generate specific anti-polio immune responses exempt from cross-reactivity with the human host. Conclusion. Peptide sequences unique to poliovirus proteins and conserved among polio strains might help formulate a specific and universal anti-polio vaccine able to react with multiple viral strains and exempt from the burden of possible cross-reactions with human proteins. As an additional advantage, using a peptide-based vaccine instead of current anti-polio DNA vaccines would eliminate the rare post-polio poliomyelitis cases and other disabling symptoms that may appear following vaccination.

  14. Applying the Concept of Peptide Uniqueness to Anti-Polio Vaccination.

    Science.gov (United States)

    Kanduc, Darja; Fasano, Candida; Capone, Giovanni; Pesce Delfino, Antonella; Calabrò, Michele; Polimeno, Lorenzo

    2015-01-01

    Although rare, adverse events may associate with anti-poliovirus vaccination thus possibly hampering global polio eradication worldwide. To design peptide-based anti-polio vaccines exempt from potential cross-reactivity risks and possibly able to reduce rare potential adverse events such as the postvaccine paralytic poliomyelitis due to the tendency of the poliovirus genome to mutate. Proteins from poliovirus type 1, strain Mahoney, were analyzed for amino acid sequence identity to the human proteome at the pentapeptide level, searching for sequences that (1) have zero percent of identity to human proteins, (2) are potentially endowed with an immunologic potential, and (3) are highly conserved among poliovirus strains. Sequence analyses produced a set of consensus epitopic peptides potentially able to generate specific anti-polio immune responses exempt from cross-reactivity with the human host. Peptide sequences unique to poliovirus proteins and conserved among polio strains might help formulate a specific and universal anti-polio vaccine able to react with multiple viral strains and exempt from the burden of possible cross-reactions with human proteins. As an additional advantage, using a peptide-based vaccine instead of current anti-polio DNA vaccines would eliminate the rare post-polio poliomyelitis cases and other disabling symptoms that may appear following vaccination.

  15. Production of a DNA Vaccine Specific for the 64 kDa Protective Antigen of Erysipelothrix rhusiopathiae

    National Research Council Canada - National Science Library

    Middlebrooks, Bobby L

    2007-01-01

    The gene for the protective antigen of E. rhusiopathiae will be inserted into a eukaryotic vector both for the production of a DNA vaccine and for large scale production of the recombinant protein (in vitro...

  16. Active immunizations with peptide-DC vaccines and passive transfer with antibodies protect neutropenic mice against disseminated candidiasis.

    Science.gov (United States)

    Xin, Hong

    2016-01-04

    We previously report that peptide-pulsed dendritic cell (DC) vaccination, which targeting two peptides (Fba and Met6) expressed on the cell surface of Candida albicans, can induce high degree of protection against disseminated candidiasis in immunocompetent mice. Passive transfer of immune sera from the peptide immunized mice or peptide-related monoclonal antibodies demonstrated that protection was medicated by peptide-specific antibodies. In this study the efficacy of active and passive immunization against disseminated candidiasis was tested in mice with cyclophosphamide-induced neutropenia. Peptide-DC vaccines were given to mice prior to induction of neutropenia. We show active immunization with either Fba or Met6 peptide-DC vaccine significantly improved the survival and reduced the fungal burden of disseminated candidiasis in those immunocompromised mice. Importantly, we show that administration of two protective monoclonal antibodies also protect neutropenic mice against the disease, implying possibility of developing a successful passive immunotherapy strategy to treat the disease and protect against disseminated candidiasis. The results of this study are crucial as they address the fundamental questions as to whether the synthetic peptide vaccine induced immunity protects the host during a neutropenic episode. We anticipate that this peptide-vaccine study will serve as the foundation of future investigations into new peptide vaccines comprised of cell surface peptides from other medically important Candida species, as well as other fungi. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Active Immunizations with Peptide-DC Vaccines and Passive Transfer with Antibodies Protect Neutropenic Mice against Disseminated Candidiasis

    Science.gov (United States)

    Xin, Hong

    2015-01-01

    We previously report that peptide-pulsed dendritic cell (DC) vaccination, which targeting two peptides (Fba and Met6) expressed on the cell surface of Candida albicans, can induce high degree of protection against disseminated candidiasis in immunocompetent mice. Passive transfer of immune sera from the peptide immunized mice or peptide-related monoclonal antibodies demonstrated that protection was medicated by peptide-specific antibodies. In this study the efficacy of active and passive immunization against disseminated candidiasis was tested in mice with cyclophosphamide-induced neutropenia. Peptide-DC vaccines were given to mice prior to induction of neutropenia. We show active immunization with either Fba or Met6 peptide-DC vaccine significantly improved the survival and reduced the fungal burden of disseminated candidiasis in those immunocompromised mice. Importantly, we show that administration of two protective monoclonal antibodies also protect neutropenic mice against the disease, implying possibility of developing a successful passive immunotherapy strategy to treat the disease and protect against disseminated candidiasis. The results of this study are crucial as they address the fundamental questions as to whether the synthetic peptide vaccine induced immunity protects the host during a neutropenic episode. We anticipate that this peptide-vaccine study will serve as the foundation of future investigations into new peptide vaccines comprised of cell surface peptides from other medically important Candida species, as well as other fungi. PMID:26620842

  18. Positive correlation between Aeromonas salmonicida vaccine antigen concentration and protection in vaccinated rainbow trout Oncorhynchus mykiss evaluated by a tail fin infection model

    DEFF Research Database (Denmark)

    Marana, M. H.; Skov, J.; Chettri, Jiwan Kumar

    2017-01-01

    Rainbow trout, Oncorhynchus mykiss (Walbaum), are able to raise a protective immune response against Aeromonas salmonicida subsp. salmonicida (AS) following injection vaccination with commercial vaccines containing formalin-killed bacteria, but the protection is often suboptimal under Danish...... mariculture conditions. We elucidated whether protection can be improved by increasing the concentration of antigen (formalin-killed bacteria) in the vaccine. Rainbow trout juveniles were vaccinated by intraperitoneal (i.p.) injection with a bacterin of Aeromonas salmonicida subsp. salmonicida strain 090710...... bacteria. The infection method proved to be efficient and could differentiate efficacies of different vaccines. It was shown that protection and antibody production in exposed fish were positively correlated to the AS antigen concentration in the vaccine....

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

    Directory of Open Access Journals (Sweden)

    David Dauvillée

    2010-12-01

    Full Text Available 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.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.This novel system paves the way for the production of clinically relevant plasmodial antigens as algal starch-based particles designated herein as amylosomes, demonstrating that

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

    Science.gov (United States)

    Dauvillée, David; Delhaye, Stéphane; Gruyer, Sébastien; Slomianny, Christian; Moretz, Samuel E; d'Hulst, Christophe; Long, Carole A; Ball, Steven G; Tomavo, Stanislas

    2010-12-15

    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. 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. This novel system paves the way for the production of clinically relevant plasmodial antigens as algal starch-based particles designated herein as amylosomes, demonstrating that efficient production

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

    OpenAIRE

    Willadsen,P.; Kemp,D. H.; Cobon,G. S.; Wright,I. G.

    1992-01-01

    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 ...

  2. Proteomic study via a non-gel based approach of meningococcal outer membrane vesicle vaccine obtained from strain CU385: a road map for discovering new antigens.

    Science.gov (United States)

    Gil, Jeovanis; Betancourt, L Zaro H; Sardiñas, Gretel; Yero, Daniel; Niebla, Olivia; Delgado, Maité; García, Darien; Pajón, Rolando; Sánchez, Aniel; González, Luis J; Padrón, Gabriel; Campa, Concepción; Sotolongo, Franklin; Barberó, Ramón; Guillén, Gerardo; Herrera, Luis; Besada, Vladimir

    2009-05-01

    This work presents the results from a study of the protein composition of outer membrane vesicles from VA-MENGOC-BC (Finlay Institute, Cuba), an available vaccine against serogroup B Neisseria meningitidis. Proteins were identified by means of SCAPE, a 2DE-free method for proteome studies. More than one hundred proteins were detected by tandem liquid chromatographymass spectrometry analysis of fractions enriched in peptides devoid of histidine or arginine residues, providing a detailed description of the vaccine. A bioinformatic analysis of the identified components resulted in the identification of 31 outer membrane proteins and three conserved hypothetical proteins, allowing the cloning, expression, purification and immunological study of two of them (NMB0088 and NMB1796) as new antigens.

  3. Induction of influenza-specific local CD8 T-cells in the respiratory tract after aerosol delivery of vaccine antigen or virus in the Babraham inbred pig

    Science.gov (United States)

    Morgan, Sophie B.; Attaf, Meriem; Szomolay, Barbara; Miles, John J.; Townsend, Alain; Bailey, Mick; Charleston, Bryan; Tchilian, Elma

    2018-01-01

    There is increasing evidence that induction of local immune responses is a key component of effective vaccines. For respiratory pathogens, for example tuberculosis and influenza, aerosol delivery is being actively explored as a method to administer vaccine antigens. Current animal models used to study respiratory pathogens suffer from anatomical disparity with humans. The pig is a natural and important host of influenza viruses and is physiologically more comparable to humans than other animal models in terms of size, respiratory tract biology and volume. It may also be an important vector in the birds to human infection cycle. A major drawback of the current pig model is the inability to analyze antigen-specific CD8+ T-cell responses, which are critical to respiratory immunity. Here we address this knowledge gap using an established in-bred pig model with a high degree of genetic identity between individuals, including the MHC (Swine Leukocyte Antigen (SLA)) locus. We developed a toolset that included long-term in vitro pig T-cell culture and cloning and identification of novel immunodominant influenza-derived T-cell epitopes. We also generated structures of the two SLA class I molecules found in these animals presenting the immunodominant epitopes. These structures allowed definition of the primary anchor points for epitopes in the SLA binding groove and established SLA binding motifs that were used to successfully predict other influenza-derived peptide sequences capable of stimulating T-cells. Peptide-SLA tetramers were constructed and used to track influenza-specific T-cells ex vivo in blood, the lungs and draining lymph nodes. Aerosol immunization with attenuated single cycle influenza viruses (S-FLU) induced large numbers of CD8+ T-cells specific for conserved NP peptides in the respiratory tract. Collectively, these data substantially increase the utility of pigs as an effective model for studying protective local cellular immunity against respiratory

  4. Curdlan sulfate-O-linked quaternized chitosan nanoparticles: potential adjuvants to improve the immunogenicity of exogenous antigens via intranasal vaccination.

    Science.gov (United States)

    Zhang, Shu; Huang, Shengshi; Lu, Lu; Song, Xinlei; Li, Pingli; Wang, Fengshan

    2018-01-01

    The development of ideal vaccine adjuvants for intranasal vaccination can provide convenience for many vaccinations. As an ideal intranasal vaccine adjuvant, it should have the properties of assisting soluble antigens to pass the mucosal barrier and potentiating both systemic and mucosal immunity via nasal administration. By using the advantages of polysaccharides, which can promote both T-helper 1 and 2 responses, curdlan sulfate (CS)- O -(2-hydroxyl)propyl-3-trimethyl ammonium chitosan chloride ( O -HTCC) nanoparticles were prepared by interacting CS with O -HTCC, and the adjuvancy of the nanoparticles was investigated. The results showed that the polysaccharide-based nanoparticles induced the proliferation and activation of antigen-presenting cells. High protein-loading efficiency was obtained by testing with the model antigen ovalbumin (Ova), and the Ova adsorbed onto the cationic CS/ O -HTCC complexes was taken up easily by the epithelium. To evaluate the capacity of the Ova/CS/ O -HTCC nanoparticles for immune enhancement in vivo, we collected and analyzed immunocytes, serum, and mucosal lavage fluid from intranasally vaccinated mice. The results showed that Ova/CS/ O -HTCC nanoparticles induced activation and maturation of antigen-presenting cells and provoked the proliferation and differentiation of lymphocytes more significantly compared to the immunization of Ova mixed with aluminum hydroxide gel. Furthermore, CS/ O -HTCC evoked a significantly higher level of Ova-specific antibodies. Therefore, these results suggest that CS/ O -HTCC nanoparticles are ideal vaccine adjuvants for soluble antigens used in intranasal or mucosal vaccination.

  5. Antigenic characterization of a formalin-inactivated poliovirus vaccine derived from live-attenuated Sabin strains.

    Science.gov (United States)

    Tano, Yoshio; Shimizu, Hiroyuki; Martin, Javier; Nishimura, Yorihiro; Simizu, Bunsiti; Miyamura, Tatsuo

    2007-10-10

    A candidate inactivated poliovirus vaccine derived from live-attenuated Sabin strains (sIPV), which are used in the oral poliovirus vaccine (OPV), was prepared in a large-production scale. The modification of viral antigenic epitopes during the formalin inactivation process was investigated by capture ELISA assays using type-specific and antigenic site-specific monoclonal antibodies (MoAbs). The major antigenic site 1 was modified during the formalin inactivation of Sabin 1. Antigenic sites 1-3 were slightly modified during the formalin inactivation of Sabin 2 strain. Sites 1 and 3 were altered on inactivated Sabin 3 virus. These alterations were different to those shown by wild-type Saukett strain, used in conventional IPV (cIPV). It has been previously reported that type 1 sIPV showed higher immunogenicity to type 1 cIPV whereas types 2 and 3 sIPV induced lower level of immunogenicity than their cIPV counterparts. Our results suggest that the differences in epitope structure after formalin inactivation may account, at least in part, for the observed differences in immunogenicity between Sabin and wild-type inactivated poliovaccines.

  6. Doubly Phosphorylated Peptide Vaccines to Protect Transgenic P301S Mice against Alzheimer’s Disease Like Tau Aggregation

    Directory of Open Access Journals (Sweden)

    Monique Richter

    2014-07-01

    Full Text Available Intracellular neurofibrillary tangles and extracellular senile plaques are potential targets for active and passive immunotherapies. In this study we used the transgenic mouse model P301S for active immunizations with peptide vaccines composed of a double phosphorylated tau neoepitope (pSer202/pThr205, pThr212/pSer214, pThr231/pSer235 and an immunomodulatory T cell epitope from the tetanus toxin or tuberculosis antigen Ag85B. Importantly, the designed vaccine combining Alzheimer’s disease (AD specific B cell epitopes with foreign (bacterial T cell epitopes induced fast immune responses with high IgG1 titers after prophylactic immunization that subsequently decreased over the observation period. The effectiveness of the immunization was surveyed by evaluating the animal behavior, as well as the pathology in the brain by biochemical and histochemical techniques. Immunized mice clearly lived longer with reduced paralysis than placebo-treated mice. Additionally, they performed significantly better in rotarod and beam walk tests at the age of 20 weeks, indicating that the disease development was slowed down. Forty-eight weeks old vaccinated mice passed the beam walk test significantly better than control animals, which together with the increased survival rates undoubtedly prove the treatment effect. In conclusion, the data provide strong evidence that active immune therapies can reduce toxic effects of deposits formed in AD.

  7. Application of recombinant hemagglutinin proteins as alternative antigen standards for pandemic influenza vaccines.

    Science.gov (United States)

    Choi, Yejin; Kwon, Seong Yi; Oh, Ho Jung; Shim, Sunbo; Chang, Seokkee; Chung, Hye Joo; Kim, Do Keun; Park, Younsang; Lee, Younghee

    2017-09-01

    The single radial immunodiffusion (SRID) assay, used to quantify hemagglutinin (HA) in influenza vaccines, requires reference reagents; however, because centralized production of reference reagents may slow the emergency deployment of vaccines, alternatives are needed. We investigated the production of HA proteins using recombinant DNA technology, rather than a traditional egg-based production process. The HA proteins were then used in an SRID assay as a reference antigen. We found that HA can be quantified in both egg-based and cell-based influenza vaccines when recombinant HAs (rHAs) are used as the reference antigen. Furthermore, we confirmed that rHAs obtained from strains with pandemic potential, such as H5N1, H7N3, H7N9, and H9N2 strains, can be utilized in the SRID assay. The rHA production process takes just one month, in contrast to the traditional process that takes three to four months. The use of rHAs may reduce the time required to produce reference reagents and facilitate timely introduction of vaccines during emergencies.

  8. 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

    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...

  9. 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

  10. Deinococcus Mn2+ -Peptide Complex: A Novel Approach to Alphavirus Vaccine Development

    Science.gov (United States)

    2016-08-05

    vaccines, ionizing radiation (IR)-induced destruction of a virus’ genome is desired, while radiation - induced damage to epitopes is...development of irradiation-based approaches to vaccine production [1-3]. During ionizing radiation (IR) exposure, the energy of the photons induces direct...specifically protect proteins from the far more damaging indirect effects of gamma (γ)-rays in aqueous preparations. Mn2+-peptide antioxidants that

  11. Assessment of the adjuvant activity of mesoporous silica nanoparticles in recombinant Mycoplasma hyopneumoniae antigen vaccines

    Directory of Open Access Journals (Sweden)

    Veridiana Gomes Virginio

    2017-01-01

    Full Text Available The adjuvant potential of two mesoporous silica nanoparticles (MSNs, SBa-15 and SBa-16, was assessed in combination with a recombinant HSP70 surface polypeptide domain from Mycoplasma hyopneumoniae, the etiological agent of porcine enzootic pneumonia (PEP. The recombinant antigen (HSP70212-600, previously shown as immunogenic in formulation with classic adjuvants, was used to immunize BALB/c mice in combination with SBa-15 or SBa-16 MSNs, and the effects obtained with these formulations were compared to those obtained with alum, the adjuvant traditionally used in anti-PEP bacterins. The HSP70212-600 + SBa-15 vaccine elicited a strong humoral immune response, with high serum total IgG levels, comparable to those obtained using HSP70212-600 + alum. The HSP70212-600 + SBa-16 vaccine elicited a moderate humoral immune response, with lower levels of total IgG. The cellular immune response was assessed by the detection of IFN-γ, IL-4 and IL-10 in splenocyte culture supernatants. The HSP70212-600 + SBa-15 vaccine increased IFN-γ, IL-4 and IL-10 levels, while no stimulation was detected with the HSP70212-600 + SBa-16 vaccine. The HSP70212-600 + SBa-15 vaccine induced a mixed Th1/Th2-type response, with an additional IL-10 mediated anti-inflammatory effect, both of relevance for an anti-PEP vaccine. Alum adjuvant controls stimulated an unspecific cellular immune response, with similar levels of cytokines detected in mice immunized either with HSP70212-600 + alum or with the adjuvant alone. The better humoral and cellular immune responses elicited in mice indicated that SBa-15 has adjuvant potential, and can be considered as an alternative to the use of alum in veterinary vaccines. The use of SBa-15 with HSP70212-600 is also promising as a potential anti-PEP subunit vaccine formulation.

  12. Histo-blood group antigens as receptors for rotavirus, new understanding on rotavirus epidemiology and vaccine strategy

    Science.gov (United States)

    Jiang, Xi; Liu, Yang; Tan, Ming

    2017-01-01

    The success of the two rotavirus (RV) vaccines (Rotarix and RotaTeq) in many countries endorses a live attenuated vaccine approach against RVs. However, the lower efficacies of both vaccines in many low- and middle-income countries indicate a need to improve the current RV vaccines. The recent discovery that RVs recognize histo-blood group antigens (HBGAs) as potential receptors has significantly advanced our understanding of RV diversity, evolution and epidemiology, providing important new insights into the performances of current RV vaccines in different populations and emphasizing a P-type-based vaccine approach. New understanding of RV diversity and evolution also raises a fundamental question about the ‘Jennerian' approach, which needs to be addressed for future development of live attenuated RV vaccines. Alternative approaches to develop safer and more cost-effective subunit vaccines against RVs are also discussed. PMID:28400594

  13. A Lactococcus lactis BFE920 feed vaccine expressing a fusion protein composed of the OmpA and FlgD antigens from Edwardsiella tarda was significantly better at protecting olive flounder (Paralichthys olivaceus) from edwardsiellosis than single antigen vaccines.

    Science.gov (United States)

    Beck, Bo Ram; Lee, Soon Ho; Kim, Daniel; Park, Ji Hye; Lee, Hyun Kyung; Kwon, San-Sung; Lee, Kwan Hee; Lee, Jae Il; Song, Seong Kyu

    2017-09-01

    Edwardsiellosis is a major fish disease that causes a significant economic damage in the aquaculture industry. Here, we assessed vaccine efficacy after feeding oral vaccines to olive flounder (Paralichthys olivaceus), either L. lactis BFE920 expressing Edwardsiella tarda outer membrane protein A (OmpA), flagellar hook protein D (FlgD), or a fusion antigen of the two. Feed vaccination was done twice with a one-week interval. Fish were fed regular feed adsorbed with the vaccines. Feed vaccination was given over the course of one week to maximize the interaction between the feed vaccines and the fish intestine. Flounder fed the vaccine containing the fusion antigen had significantly elevated levels T cell genes (CD4-1, CD4-2, and CD8α), type 1 helper T cell (Th1) subset indicator genes (T-bet and IFN-γ), and antigen-specific antibodies compared to the groups fed the single antigen-expressing vaccines. Furthermore, the superiority of the fusion vaccine was also observed in survival rates when fish were challenged with E. tarda: OmpA-FlgD-expressing vaccine (82.5% survival); FlgD-vaccine (55.0%); OmpA-vaccine (50%); WT L. lactis BFE920 (37.5%); Ctrl (10%). In addition, vaccine-fed fish exhibited increased weight gain (∼20%) and a decreased feed conversion ratio (∼20%) during the four week vaccination period. Flounder fed the FlgD-expressing vaccine, either the single or the fusion form, had significantly increased expression of TLR5M, IL-1β, and IL-12p40, suggesting that the FlgD may be a ligand of olive flounder TLR5M receptor or closely related to the TLR5M pathway. In conclusion, the present study demonstrated that olive flounder fed L. lactis BFE920 expressing a fusion antigen composed of E. tarda OmpA and FlgD showed a strong protective effect against edwardsiellosis indicating this may be developed as an E. tarda feed vaccine. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. 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

  15. A Brief Review of Computer-Assisted Approaches to Rational Design of Peptide Vaccines

    Directory of Open Access Journals (Sweden)

    Ashesh Nandy

    2016-05-01

    Full Text Available The growing incidences of new viral diseases and increasingly frequent viral epidemics have strained therapeutic and preventive measures; the high mutability of viral genes puts additional strains on developmental efforts. Given the high cost and time requirements for new drugs development, vaccines remain as a viable alternative, but there too traditional techniques of live-attenuated or inactivated vaccines have the danger of allergenic reactions and others. Peptide vaccines have, over the last several years, begun to be looked on as more appropriate alternatives, which are economically affordable, require less time for development and hold the promise of multi-valent dosages. The developments in bioinformatics, proteomics, immunogenomics, structural biology and other sciences have spurred the growth of vaccinomics where computer assisted approaches serve to identify suitable peptide targets for eventual development of vaccines. In this mini-review we give a brief overview of some of the recent trends in computer assisted vaccine development with emphasis on the primary selection procedures of probable peptide candidates for vaccine development.

  16. MHC class II-derived peptides can bind to class II molecules, including self molecules, and prevent antigen presentation

    DEFF Research Database (Denmark)

    Rosloniec, E F; Vitez, L J; Buus, S

    1990-01-01

    the alpha k-3 peptide binds slightly less well. These combined data, suggesting that class II-derived peptides can bind to MHC class II molecules, including the autologous molecule from which they are derived, have important implications for the molecular basis of alloreactivity and autoreactivity. Further...... found in the first and third polymorphic regions (PMR) of the A alpha k chain (alpha k-1 and alpha k-3) were capable of inhibiting the presentation of three different HEL-derived peptide antigens to their appropriate T cells. In addition, the alpha k-1 peptide inhibited the presentation of the OVA(323......-339) immunodominant peptide to the I-Ad-restricted T cell hybridomas specific for it. Prepulsing experiments demonstrated that the PMR peptides were interacting with the APC and not with the T cell hybridomas. These observations were confirmed and extended by the demonstration that the alpha k-1 and alpha k-3...

  17. Antigen processing of glycoconjugate vaccines; the polysaccharide portion of the pneumococcal CRM(197) conjugate vaccine co-localizes with MHC II on the antigen processing cell surface.

    Science.gov (United States)

    Lai, Zengzu; Schreiber, John R

    2009-05-21

    Pneumococcal (Pn) polysaccharides (PS) are T-independent (TI) antigens and do not induce immunological memory or antibodies in infants. Conjugation of PnPS to the carrier protein CRM(197) induces PS-specific antibody in infants, and memory similar to T-dependent (Td) antigens. Conjugates have improved immunogenicity via antigen processing and presentation of carrier protein with MHC II and recruitment of T cell help, but the fate of the PS attached to the carrier is unknown. To determine the location of the PS component of PnPS-CRM(197) in the APC, we separately labeled PS and protein and tracked their location. The PS of types 14-CRM(197) and 19F-CRM(197) was specifically labeled by Alexa Fluor 594 hydrazide (red). The CRM(197) was separately labeled red in a reaction that did not label PS. Labeled antigens were incubated with APC which were fixed, permeabilized and incubated with anti-MHC II antibody labeled green by Alexa Fluor 488, followed by confocal microscopy. Labeled CRM(197) was presented on APC surface and co-localized with MHC II (yellow). Labeled unconjugated 14 or 19F PS did not go to the APC surface, but PS labeled 14-CRM(197) and 19F-CRM(197) was internalized and co-localized with MHC II. Monoclonal antibody to type 14 PS bound to intracellular type 14 PS and PS-CRM(197). Brefeldin A and chloroquine blocked both CRM(197) and PS labeled 14-CRM(197) and 19F-CRM(197) from co-localizing with MHC II. These data suggest that the PS component of the CRM(197) glycoconjugate enters the endosome, travels with CRM(197) peptides to the APC surface and co-localizes with MHC II.

  18. A recombinant multi-antigen vaccine with broad protection potential against avian pathogenic Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Angelica Van Goor

    Full Text Available Chickens are a major source of protein worldwide, yet infectious diseases continue to threaten the poultry industry. Avian pathogenic Escherichia coli (APEC, a subgroup of extraintestinal pathogenic E. coli (ExPEC, causes colibacillosis in chickens resulting in economic loss because of treatment, condemnation of products, and death. In this study, we evaluated a recombinant antigens (rAg vaccine combining common ExPEC surface proteins EtsC, OmpA, OmpT, and TraT for broad protective potential against APEC infections in chickens. The specific objectives were to evaluate antibody (serum and cytokines (lymphoid organs responses to vaccination; in vitro bactericidal ability of serum and splenocytes against multiple APEC serotypes; and in vivo protection against APEC challenge in chickens. Groups of four-day old chickens (N = 10 were vaccinated twice (two-week interval subcutaneously with rAgs alone or in combination and CpG adjuvant or PBS (control. IgY antibody in the serum and mRNA expression of IL-1β, IL-6, IL-18, IFN-γ, IL-4, IFN-β, and IL-8 in bursa, spleen, and thymus were measured using ELISA and RT-qPCR, respectively. Serum and splenocytes were tested for their bactericidal ability in vitro against multiple APEC isolates. Vaccinated and non-vaccinated chickens were challenged with 108 CFU of APEC-O2 via air sac at 31 days post first vaccination. Vaccine protection was determined by the decrease of bacterial loads in blood and organs (lung, heart, spleen, and liver, as well as gross colibacillosis lesion scores in air sac, heart, and liver. Vaccination significantly (P < 0.05 elicited IgY against specific antigens, induced immune related mRNA expression in the spleen and bursa, reduced in vitro growth of multiple APEC serotypes, and decreased bacterial loads in the heart and spleen, and gross lesion scores of the air sac, heart and liver in chickens. The vaccine reported may be used to provide broad protection against APEC strains

  19. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    International Nuclear Information System (INIS)

    Kim, Sun Young; Song, Kyung-A; Kieff, Elliott; Kang, Myung-Soo

    2012-01-01

    Highlights: ► Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. ► A small molecule and a peptide as EBNA1 dimerization inhibitors identified. ► Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. ► Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)’s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459–607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-Jκ binding to the Jκ site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560–574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated with EBNA1 in vitro, and repressed EBNA1-dependent transcription in vivo. Collectively, this study describes two

  20. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Young; Song, Kyung-A [Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kieff, Elliott [Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States); Kang, Myung-Soo, E-mail: mkang@skku.edu [Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States)

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. Black-Right-Pointing-Pointer A small molecule and a peptide as EBNA1 dimerization inhibitors identified. Black-Right-Pointing-Pointer Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. Black-Right-Pointing-Pointer Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)'s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459-607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-J{kappa} binding to the J{kappa} site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560-574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated

  1. 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......G concentrations. The two P. pastoris-produced MSP-1(19)-induced IgGs conferred the lowest growth inhibition. Comparative analysis of immunogenicity of vaccine antigens can be used to prioritize candidates before moving to expensive GMP production and clinical testing. The assays used have given discriminating...

  2. 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.

  3. 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.

  4. Effective plague vaccination via oral delivery of plant cells expressing F1-V antigens in chloroplasts.

    Science.gov (United States)

    Arlen, Philip A; Singleton, Michael; Adamovicz, Jeffrey J; Ding, Yi; Davoodi-Semiromi, Abdolreza; Daniell, Henry

    2008-08-01

    The chloroplast bioreactor is an alternative to fermentation-based systems for production of vaccine antigens and biopharmaceuticals. We report here expression of the plague F1-V fusion antigen in chloroplasts. Site-specific transgene integration and homoplasmy were confirmed by PCR and Southern blotting. Mature leaves showed the highest level of transgene expression on the third day of continuous illumination, with a maximum level of 14.8% of the total soluble protein. Swiss Webster mice were primed with adjuvant-containing subcutaneous (s.c.) doses of F1-V and then boosted with either adjuvanted s.c. doses (s.c. F1-V mice) or unadjuvanted oral doses (oral F1-V mice). Oral F1-V mice had higher prechallenge serum immunoglobulin G1 (IgG1) titers than s.c. F1-V mice. The corresponding serum levels of antigen-specific IgG2a and IgA were 2 and 3 orders of magnitude lower, respectively. After vaccination, mice were exposed to an inhaled dose of 1.02 x 10(6) CFU of aerosolized Yersinia pestis CO92 (50% lethal dose, 6.8 x 10(4) CFU). All control animals died within 3 days. F1-V given s.c. (with adjuvant) protected 33% of the immunized mice, while 88% of the oral F1-V mice survived aerosolized Y. pestis challenge. A comparison of splenic Y. pestis CFU counts showed that there was a 7- to 10-log reduction in the mean bacterial burden in survivors. Taken together, these data indicate that oral booster doses effectively elicit protective immune responses in vivo. In addition, this is the first report of a plant-derived oral vaccine that protected animals from live Y. pestis challenge, bringing the likelihood of lower-cost vaccines closer to reality.

  5. Epidermal growth factor receptor VIII peptide vaccination is efficacious against established intracerebral tumors.

    Science.gov (United States)

    Heimberger, Amy B; Crotty, Laura E; Archer, Gary E; Hess, Kenneth R; Wikstrand, Carol J; Friedman, Allan H; Friedman, Henry S; Bigner, Darell D; Sampson, John H

    2003-09-15

    The epidermal growth factor receptor (EGFR) is often amplified and structurally rearranged in malignant gliomas and other tumors such as breast and lung, with the most common mutation being EGFRvIII. In the study described here, we tested in mouse models a vaccine consisting of a peptide encompassing the tumor-specific mutated segment of EGFRvIII (PEP-3) conjugated to keyhole limpet hemocyanin [KLH (PEP-3-KLH)]. C57BL/6J or C3H mice were vaccinated with PEP-3-KLH and subsequently challenged either s.c. or intracerebrally with a syngeneic melanoma cell line stably transfected with a murine homologue of EGFRvIII. Control mice were vaccinated with KLH. To test its effect on established tumors, C3H mice were also challenged intracerebrally and subsequently vaccinated with PEP-3-KLH. S.c. tumors developed in all of the C57BL/6J mice vaccinated with KLH in Freund's adjuvant, and there were no long-term survivors. Palpable tumors never developed in 70% of the PEP-3-KLH-vaccinated mice. In the C57BL/6J mice receiving the PEP-3-KLH vaccine, the tumors that did develop were significantly smaller than those in the control group (P PEP-3-KLH vaccination did not result in significant cytotoxic responses in standard cytotoxicity assays; however, antibody titers against PEP-3 were enhanced. The passive transfer of sera from the immunized mice to nonimmunized mice protected 31% of the mice from tumor development (P PEP-3-KLH-vaccinated mice. Peptide vaccination was also sufficiently potent to have marked efficacy against intracerebral tumors, resulting in a >173% increase in median survival time, with 80% of the C3H mice achieving long-term survival (P = 0.014). In addition, C3H mice with established intracerebral tumor that received a single treatment of PEP-3-KLH showed a 26% increase in median survival time, with 40% long-term survival (P = 0.007). Vaccination with an EGFRvIII-specific peptide is efficacious against both s.c. and established intracerebral tumors. The

  6. Evidence for a role of regulatory T cells in mediating the atheroprotective effect of apolipoprotein B peptide vaccine.

    Science.gov (United States)

    Wigren, M; Kolbus, D; Dunér, P; Ljungcrantz, I; Söderberg, I; Björkbacka, H; Fredrikson, G N; Nilsson, J

    2011-05-01

    Autoimmune responses against oxidized low-density lipoprotein are considered to play an important pro-inflammatory role in atherosclerosis and to promote disease progression. T-regulatory cells (Tregs) are immunosuppressive cells that have an important part in maintaining self-tolerance and protection against autoimmunity. We investigated whether aBp210, a prototype atherosclerosis vaccine based on a peptide sequence derived from apolipoprotein B, inhibits atherosclerosis through the activation of Tregs. Six-week-old Apoe(-/-) mice were immunized with aBp210 and received booster immunizations 3 and 5 weeks later, as well as 1 week before being killed at 25 weeks of age. At 12 weeks, immunized mice had increased expression of the Treg marker CD25 on circulating CD4 cells, and concanavalin A (Con A)-induced interferon-γ, interleukin (IL)-4, and IL-10 release from splenocytes was markedly depressed. At 25 weeks, there was a fivefold expansion of splenic CD4+ CD25+ Foxp3 Tregs, a 65% decrease in Con A-induced splenic T-cell proliferation and a 37% reduction in the development of atherosclerosis in immunized mice. Administration of blocking antibodies against CD25 neutralized aBp210-induced Treg activation as well as the reduction of atherosclerosis. The present findings demonstrate that immunization of Apoe(-/-) mice with the apolipoprotein B peptide vaccine aBp210 is associated with activation of Tregs. Administration of antibodies against CD25 results in depletion of Tregs and blocking of the atheroprotective effect of the vaccine. Modulation in atherosclerosis-related autoimmunity by antigen-specific activation of Tregs represents a novel approach for treatment of atherosclerosis. © 2010 The Association for the Publication of the Journal of Internal Medicine.

  7. Application of Pharmacokinetics Modelling to Predict Human Exposure of a Cationic Liposomal Subunit Antigen Vaccine System

    Directory of Open Access Journals (Sweden)

    Raj K. S. Badhan

    2017-12-01

    Full Text Available The pharmacokinetics of a liposomal subunit antigen vaccine system composed of the cationic lipid dimethyldioctadecylammonium bromide (DDA and the immunostimulatory agent trehalose 6,6-dibehenate (TDB (8:1 molar ratio combined with the Ag85B-ESAT-6 (H1 antigen were modelled using mouse in-vivo data. Compartment modelling and physiologically based pharmacokinetics (PBPK were used to predict the administration site (muscle and target site (lymph temporal concentration profiles and factors governing these. Initial estimates using compartmental modelling established that quadriceps pharmacokinetics for the liposome demonstrated a long half-life (22.6 days compared to the associated antigen (2.62 days. A mouse minimal-PBPK model was developed and successfully predicted quadriceps liposome and antigen pharmacokinetics. Predictions for the popliteal lymph node (PLN aligned well at earlier time-points. A local sensitivity analysis highlighted that the predicted AUCmuscle was sensitive to the antigen degradation constant kdeg (resulting in a 3-log change more so than the fraction escaping the quadriceps (fe (resulting in a 10-fold change, and the predicted AUCPLN was highly sensitive to fe. A global sensitivity analysis of the antigen in the muscle demonstrated that model predictions were within the 50th percentile for predictions and showed acceptable fits. To further translate in-vitro data previously generated by our group, the mouse minimal-PBPK model was extrapolated to humans and predictions made for antigen pharmacokinetics in muscle and PLN. Global analysis demonstrated that both kdeg and fe had a minimal impact on the resulting simulations in the muscle but a greater impact in the PLN. In summary, this study has predicted the in-vivo fate of DDA:TDB:H1 in humans and demonstrated the roles that formulation degradation and fraction escaping the depot site can play upon the overall depot effect within the site of administration.

  8. Active immunization with the peptide epitope vaccine Aβ3-10-KLH induces a Th2-polarized anti-Aβ antibody response and decreases amyloid plaques in APP/PS1 transgenic mice.

    Science.gov (United States)

    Ding, Li; Meng, Yuan; Zhang, Hui-Yi; Yin, Wen-Chao; Yan, Yi; Cao, Yun-Peng

    2016-11-10

    Active amyloid-β (Aβ) immunotherapy is effective in preventing Aβ deposition, facilitating plaque clearance, and improving cognitive functions in mouse models of Alzheimer's disease (AD). Developing a safe and effective AD vaccine requires a delicate balance between inducing adequate humoral immune responses and avoiding T cell-mediated autoimmune responses. In this study, we designed 2 peptide epitope vaccines, Aβ3-10-KLH and 5Aβ3-10, prepared respectively by coupling Aβ3-10 to the immunogenic carrier protein keyhole limpet hemocyanin (KLH) or by joining 5 Aβ3-10 epitopes linearly in tandem. Young APP/PS1 mice were immunized subcutaneously with Aβ3-10-KLH or 5Aβ3-10 mixed with Freund's adjuvant, and the immunopotencies of these Aβ3-10 peptide vaccines were tested. Aβ3-10-KLH elicited a robust Th2-polarized anti-Aβ antibody response and inhibited Aβ deposition in APP/PS1 mice. However, 5Aβ3-10 did not induce an effective humoral immune response. These results indicated that Aβ3-10-KLH may be a safe and efficient vaccine for AD and that conjugating the antigen to a carrier protein may be more effective than linking multiple peptide antigens in tandem in applications for antibody production and vaccine preparation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Neisseria meningitidis antigen NMB0088: sequence variability, protein topology and vaccine potential.

    Science.gov (United States)

    Sardiñas, Gretel; Yero, Daniel; Climent, Yanet; Caballero, Evelin; Cobas, Karem; Niebla, Olivia

    2009-02-01

    The significance of Neisseria meningitidis serogroup B membrane proteins as vaccine candidates is continually growing. Here, we studied different aspects of antigen NMB0088, a protein that is abundant in outer-membrane vesicle preparations and is thought to be a surface protein. The gene encoding protein NMB0088 was sequenced in a panel of 34 different meningococcal strains with clinical and epidemiological relevance. After this analysis, four variants of NMB0088 were identified; the variability was confined to three specific segments, designated VR1, VR2 and VR3. Secondary structure predictions, refined with alignment analysis and homology modelling using FadL of Escherichia coli, revealed that almost all the variable regions were located in extracellular loop domains. In addition, the NMB0088 antigen was expressed in E. coli and a procedure for obtaining purified recombinant NMB0088 is described. The humoral immune response elicited in BALB/c mice was measured by ELISA and Western blotting, while the functional activity of these antibodies was determined in a serum bactericidal assay and an animal protection model. After immunization in mice, the recombinant protein was capable of inducing a protective response when it was administered inserted into liposomes. According to our results, the recombinant NMB0088 protein may represent a novel antigen for a vaccine against meningococcal disease. However, results from the variability study should be considered for designing a cross-protective formulation in future studies.

  10. Impact of genetic changes, pathogenicity and antigenicity on Enterovirus- A71 vaccine development.

    Science.gov (United States)

    Yee, Pinn Tsin Isabel; Laa Poh, Chit

    2017-06-01

    Enterovirus-A71 (EV-A71) is an etiological agent of the hand, foot and mouth disease (HFMD). EV-A71 infection produces high fever and ulcers in children. Some EV-A71 strains produce severe infections leading to pulmonary edema and death. Although the protective efficacy of the inactivated vaccine (IV) was ≥90% against mild HFMD, there was approximately 80% protection against severe HFMD. The monovalent EV-A71 IV elicits humoral immunity but lacks long-term immunogenicity. Spontaneous mutations of the EV-A71 genome could lead to antigenicity changes and the virus may not be neutralized by antibodies elicited by the IV. A better alternative would be the live attenuated vaccine (LAV) that elicits cellular and humoral immunity. The LAV induces excellent antigenicity and chances of reversion is reduced by presence of multiple mutations which could reduce pathogenicity. Besides CV-A16, outbreaks have been caused by CV-A6 and CV-A10, hence the development of bivalent and trivalent vaccines is required. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Expression of the Gastrin-Releasing Peptide Receptor, the Prostate Stem Cell Antigen and the Prostate-Specific Membrane Antigen in Lymph Node and Bone Metastases of Prostate Cancer

    NARCIS (Netherlands)

    Ananias, Hildo J. K.; van den Heuvel, Marius C.; Helfrich, Wijnand; de Jong, Igle J.

    2009-01-01

    OBJECTIVE. Cell membrane antigens like the gastrin-releasing peptide receptor (GRPR), the prostate stem cell antigen (PSCA), and the prostate-specific membrane antigen (PSMA), expressed in prostate cancer, are attractive targets for new therapeutic and diagnostic applications. Therefore, we

  12. Mechanistic studies on long peptide-based vaccines for the use in cancer therapy

    NARCIS (Netherlands)

    Bijker, Martijn Sander

    2007-01-01

    Synthetic peptide vaccines aiming at the induction of a protective CD8+ T-cell response against infectious or malignant diseases are widely used in the clinic but, despite their success in animal models, they do not yet live up to their promise in humans. This thesis assesses the development of

  13. Idala: An unnamed Function Peptide Vaccine for Tuberculosis

    African Journals Online (AJOL)

    lysate and injected in mice for immunogenicity experiment up to 42 days. ELISA tests with anti- ... Color development in a microplate reader was ... potential new tuberculosis vaccine candidate. [3]. ..... New York and London: Garland Science,.

  14. Non-immunogenicity of overlapping gag peptides pulsed on autologous cells after vaccination of HIV infected individuals.

    Directory of Open Access Journals (Sweden)

    Henrik N Kløverpris

    Full Text Available HIV Gag-specific CD4+ and CD8+ T-cell responses are important for HIV immune control. Pulsing overlapping Gag peptides on autologous lymphocytes (OPAL has proven immunogenic and effective in reducing viral loads in multiple pigtail macaque studies, warranting clinical evaluation.We performed a phase I, single centre, placebo-controlled, double-blinded and dose-escalating study to evaluate the safety and preliminary immunogenicity of a novel therapeutic vaccine approach 'OPAL-HIV-Gag(c'. This vaccine is comprised of 120 15mer peptides, overlapping by 11 amino acids, spanning the HIV Gag C clade sequence proteome, pulsed on white blood cells enriched from whole blood using a closed system, followed by intravenous reinfusion. Patients with undetectable HIV viral loads (<50 copies/ml plasma on HAART received four administrations at week 0, 4, 8 and 12, and were followed up for 12 weeks post-treatment. Twenty-three people were enrolled in four groups: 12 mg (n = 6, 24 mg (n = 7, 48 mg (n = 2 or matching placebo (n = 8 with 18 immunologically evaluable. T-cell immunogenicity was assessed by IFNγ ELIspot and intracellular cytokine staining (ICS.The OPAL-HIV-Gag(c peptides were antigenic in vitro in 17/17 subjects. After vaccination with OPAL-HIV-Gag(c, 1/6 subjects at 12 mg and 1/6 subjects at 24 mg dose groups had a 2- and 3-fold increase in ELIspot magnitudes from baseline, respectively, of Gag-specific CD8+ T-cells at week 14, compared to 0/6 subjects in the placebo group. No Gag-specific CD4+ T-cell responses or overall change in Rev, Nef, Tat and CMV specific responses were detected. Marked, transient and self-limiting lymphopenia was observed immediately post-vaccination (4 hours in OPAL-HIV-Gag(c but not in placebo recipients, with median fall from 1.72 to 0.67 million lymphocytes/mL for active groups (P<0.001, compared to post-placebo from 1.70 to 1.56 lymphocytes/ml (P = 0.16.Despite strong immunogenicity observed in

  15. 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.

  16. Challenges and opportunities of using liquid chromatography and mass spectrometry methods to develop complex vaccine antigens as pharmaceutical dosage forms.

    Science.gov (United States)

    Hickey, John M; Sahni, Neha; Toth, Ronald T; Kumru, Ozan S; Joshi, Sangeeta B; Middaugh, C Russell; Volkin, David B

    2016-10-01

    Liquid chromatographic methods, combined with mass spectrometry, offer exciting and important opportunities to better characterize complex vaccine antigens including recombinant proteins, virus-like particles, inactivated viruses, polysaccharides, and protein-polysaccharide conjugates. The current abilities and limitations of these physicochemical methods to complement traditional in vitro and in vivo vaccine potency assays are explored in this review through the use of illustrative case studies. Various applications of these state-of-the art techniques are illustrated that include the analysis of influenza vaccines (inactivated whole virus and recombinant hemagglutinin), virus-like particle vaccines (human papillomavirus and hepatitis B), and polysaccharide linked to protein carrier vaccines (pneumococcal). Examples of utilizing these analytical methods to characterize vaccine antigens in the presence of adjuvants, which are often included to boost immune responses as part of the final vaccine dosage form, are also presented. Some of the challenges of using chromatographic and LC-MS as physicochemical assays to routinely test complex vaccine antigens are also discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Positive hepatitis B surface antigen tests due to recent vaccination: a persistent problem

    Directory of Open Access Journals (Sweden)

    Rysgaard Carolyn D

    2012-09-01

    Full Text Available Abstract Background Hepatitis B virus (HBV is a common cause of viral hepatitis with significant health complications including cirrhosis and hepatocellular carcinoma. Assays for hepatitis B surface antigen (HBsAg are the most frequently used tests to detect HBV infection. Vaccination for HBV can produce transiently detectable levels of HBsAg in patients. However, the time course and duration of this effect is unclear. The objective of this retrospective study was to clarify the frequency and duration of transient HBsAg positivity following vaccination against HBV. Methods The electronic medical record at an academic tertiary care medical center was searched to identify all orders for HBsAg within a 17 month time period. Detailed chart review was performed to identify all patients who were administered HBV vaccine within 180 days prior to HBsAg testing and also to ascertain likely cause of weakly positive (grayzone results. Results During the 17 month study period, 11,719 HBsAg tests were ordered on 9,930 patients. There were 34 tests performed on 34 patients who received HBV vaccine 14 days or less prior to HBsAg testing. Of these 34 patients, 11 had grayzone results for HBsAg that could be attributed to recent vaccination. Ten of the 11 patients were renal dialysis patients who were receiving HBsAg testing as part of routine and ongoing monitoring. Beyond 14 days, there were no reactive or grayzone HBsAg tests that could be attributed to recent HBV vaccination. HBsAg results reached a peak COI two to three days following vaccination before decaying. Further analysis of all the grayzone results within the 17 month study period (43 results out of 11,719 tests revealed that only 4 of 43 were the result of true HBV infection as verified by confirmatory testing. Conclusions Our study confirms that transient HBsAg positivity can occur in patients following HBV vaccination. The results suggest this positivity is unlikely to persist beyond 14 days

  18. P5 HER2/neu-derived peptide conjugated to liposomes containing MPL adjuvant as an effective prophylactic vaccine formulation for breast cancer.

    Science.gov (United States)

    Shariat, Sheida; Badiee, Ali; Jalali, Seyed Amir; Mansourian, Mercedeh; Yazdani, Mona; Mortazavi, Seyed Alireza; Jaafari, Mahmoud Reza

    2014-12-01

    Vaccines containing synthetic peptides derived from tumor-associated antigens (TAA) can elicit potent cytotoxic T lymphocyte (CTL) response if they are formulated in an optimal vaccine delivery system. The aim of this study was to develop a simple and effective lipid-based vaccine delivery system using P5 HER2/neu-derived peptide conjugated to Maleimide-PEG2000-DSPE. The conjugated lipid was then incorporated into liposomes composed of DMPC:DMPG:Chol:DOPE containing Monophosphoryl lipid A (MPL) (Lip-DOPE-P5-MPL). Different liposome formulations were prepared and characterized for their physicochemical properties. To evaluate anti-tumoral efficacy, BALB/c mice were immunized subcutaneously 3 times in two-week intervals and the generated immune response was studied. The results demonstrated that Lip-DOPE-P5-MPL induced a significantly higher IFN-γ production by CD8+ T cells intracellularly which represents higher CTL response in comparison with other control formulations. CTL response induced by this formulation caused the lowest tumor size and the longest survival time in a mice model of TUBO tumor. The encouraging results achieved by Lip-DOPE-P5-MPL formulation could make it a promising candidate in developing effective vaccines against Her2 positive breast cancers. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Arginine (Di)methylated Human Leukocyte Antigen Class I Peptides Are Favorably Presented by HLA-B*07

    NARCIS (Netherlands)

    Marino, Fabio; Mommen, Geert P M; Jeko, Anita; Meiring, Hugo D; van Gaans-van den Brink, Jacqueline A M; Scheltema, Richard A; van Els, Cécile A C M; Heck, Albert J R

    Alterations in protein post-translational modification (PTM) are recognized hallmarks of diseases. These modifications potentially provide a unique source of disease-related human leukocyte antigen (HLA) class I-presented peptides that can elicit specific immune responses. While phosphorylated HLA

  20. 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.

  1. 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

    -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 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...... to that 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...

  2. 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.

  3. Recombinant heat shock protein 70 functional peptide and alpha-fetoprotein epitope peptide vaccine elicits specific anti-tumor immunity.

    Science.gov (United States)

    Wang, Xiao-Ping; Wang, Qiao-Xia; Lin, Huan-Ping; Xu, Bing; Zhao, Qian; Chen, Kun

    2016-11-01

    Alpha-fetoprotein (AFP) is a marker of hepatocellular carcinoma (HCC) and serves as a target for immunotherapy. However, current treatments targeting AFP are not reproducible and do not provide complete protection against cancer. This issue may be solved by developing novel therapeutic vaccines with enhanced immunogenicity that could effectively target AFP-expressing tumors. In this study, we report construction of a therapeutic peptide vaccine by linking heat shock protein 70 (HSP70) functional peptide to the AFP epitope to obtain HSP70-P/AFP-P. This novel peptide was administered into BALB/c mice to observe the effects. Quantification of AFP-specific CD8 + T cells that secrete IFN-γ in these mice via ELISPOT revealed the synergistic effects of HSP70-P/AFP-P with increased numbers of AFP-specific CD8 + T cells. Similarly, ELISA analysis showed increased granzyme B and perforin released by natural killer cells. Moreover, in vitro cytotoxic T-lymphocyte assays and in vivo tumor preventive experiments clearly showed the higher antitumor effects of HSP70-P/AFP-P against AFP-expressing tumors. These results show that treatment of BALB/c mice with HSP70-P/AFP-P induced stronger T-cells responses and improved protective immunity. Our data suggest that HSP70-P/AFP-P may be used as a therapeutic approach in the treatment of AFP-expressing cancers.

  4. Antigenicity of peptides comprising the immunosuppressive domain of the retroviral envelope glycoprotein [version 1; referees: 2 approved

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    Bryony Jenkins

    2016-12-01

    Full Text Available To achieve persistent infection of the host, viruses often subvert or suppress host immunity through mechanisms that are not entirely understood. The envelope glycoprotein of several retroviruses is thought to possess potent immunosuppressive activity, mapped to a 17-amino acid residue conserved domain. Synthetic peptides corresponding to this immunosuppressive domain can inhibit lymphocyte activation, whereas mutation of key domain residues can increase the lymphocyte response to linked antigenic epitopes. Using three T cell receptors (TCRs of defined specificity, we examine the effect of the immunosuppressive domain on the T cell response to their respective antigenic peptides. We find that fusion of a T cell epitope to the immunosuppressive domain can greatly modulate its potency. However, the effects heavily depend on the particular combination of TCR and peptide-major histocompatibility complex class II (pMHC II, and are mimicked by sequence-scrambled peptides of similar length, suggesting they operate at the level of TCR-pMHC interaction. These results offer an alternative explanation for the immunogenicity of T cell epitopes comprising the putative immunosuppressive domain, which is more consistent with an effect on peptide antigenicity than true immunosuppressive activity.

  5. Antigenicity of peptides comprising the immunosuppressive domain of the retroviral envelope glycoprotein [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Bryony Jenkins

    2017-02-01

    Full Text Available To achieve persistent infection of the host, viruses often subvert or suppress host immunity through mechanisms that are not entirely understood. The envelope glycoprotein of several retroviruses is thought to possess potent immunosuppressive activity, mapped to a 17-amino acid residue conserved domain. Synthetic peptides corresponding to this immunosuppressive domain can inhibit lymphocyte activation, whereas mutation of key domain residues can increase the lymphocyte response to linked antigenic epitopes. Using three T cell receptors (TCRs of defined specificity, we examine the effect of the immunosuppressive domain on the T cell response to their respective antigenic peptides. We find that fusion of a T cell epitope to the immunosuppressive domain can greatly modulate its potency. However, the effects heavily depend on the particular combination of TCR and peptide-major histocompatibility complex class II (pMHC II, and are mimicked by sequence-scrambled peptides of similar length, suggesting they operate at the level of pMHC formation or TCR-pMHC interaction. These results offer an alternative explanation for the immunogenicity of T cell epitopes comprising the putative immunosuppressive domain, which is more consistent with an effect on peptide antigenicity than true immunosuppressive activity.

  6. 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

  7. The role of peptide and DNA vaccines in myeloid leukemia immunotherapy

    Directory of Open Access Journals (Sweden)

    Lin Chen

    2013-02-01

    Full Text Available Abstract While chemotherapy and targeted therapy are successful in inducing the remission of myeloid leukemia as acute myeloid leukemia (AML and chronic myeloid leukemia (CML, the disease remains largely incurable. This observation is likely due to the drug resistance of leukemic cells, which are responsible for disease relapse. Myeloid leukemia vaccines may most likely be beneficial for eradicating minimal residual disease after treatment with chemotherapy or targeted therapy. Several targeted immunotherapies using leukemia vaccines have been heavily investigated in clinical and preclinical trials. This review will focus on peptides and DNA vaccines in the context of myeloid leukemias, and optimal strategies for enhancing the efficacy of vaccines based on myeloid leukemia immunization are also summarized.

  8. Cross-protective peptide vaccine against influenza A viruses developed in HLA-A*2402 human immunity model.

    Directory of Open Access Journals (Sweden)

    Toru Ichihashi

    Full Text Available BACKGROUND: The virus-specific cytotoxic T lymphocyte (CTL induction is an important target for the development of a broadly protective human influenza vaccine, since most CTL epitopes are found on internal viral proteins and relatively conserved. In this study, the possibility of developing a strain/subtype-independent human influenza vaccine was explored by taking a bioinformatics approach to establish an immunogenic HLA-A24 restricted CTL epitope screening system in HLA-transgenic mice. METHODOLOGY/PRINCIPAL FINDINGS: HLA-A24 restricted CTL epitope peptides derived from internal proteins of the H5N1 highly pathogenic avian influenza A virus were predicted by CTL epitope peptide prediction programs. Of 35 predicted peptides, six peptides exhibited remarkable cytotoxic activity in vivo. More than half of the mice which were subcutaneously vaccinated with the three most immunogenic and highly conserved epitopes among three different influenza A virus subtypes (H1N1, H3N2 and H5N1 survived lethal influenza virus challenge during both effector and memory CTL phases. Furthermore, mice that were intranasally vaccinated with these peptides remained free of clinical signs after lethal virus challenge during the effector phase. CONCLUSIONS/SIGNIFICANCE: This CTL epitope peptide selection system can be used as an effective tool for the development of a cross-protective human influenza vaccine. Furthermore this vaccine strategy can be applicable to the development of all intracellular pathogens vaccines to induce epitope-specific CTL that effectively eliminate infected cells.

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

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    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

  10. Dairy cows produce cytokine and cytotoxic T cell responses following vaccination with an antigenic fraction from Streptococcus uberis.

    Science.gov (United States)

    Wedlock, D Neil; Buddle, Bryce M; Williamson, John; Lacy-Hulbert, S Jane; Turner, Sally-Anne; Subharat, Supatsak; Heiser, Axel

    2014-07-15

    Streptococcus uberis is a major cause of mastitis in dairy cows worldwide and currently, there is no vaccine commercially available against this form of mastitis. In the current study, cell-free extracts (CFE) were prepared from each of three different S. uberis strains, designated as #3, #24 and #363 representative of the three main sequence types of S. uberis that cause mastitis in New Zealand. These proteins were formulated into vaccines with Emulsigen-D and the immunogenicity of the vaccines was determined in both calves and dairy cows. Two groups of calves (n=5/group) were vaccinated subcutaneously with CFE from strain #24 or strains #3, #24 and #363 formulated with Emulsigen-D, respectively. A third group (n=5) was vaccinated with CFE from the three strains formulated with Emulsigen-D and also containing recombinant bovine granulocyte macrophage colony-stimulating factor while, a control group (n=5) was not vaccinated. Vaccinated animals produced strong antibody responses to the S. uberis antigens and an antigen-specific cytotoxic effect against blood monocytes/macrophages that had phagocytosed S. uberis, with no significant differences in responses observed between the three vaccinated groups. In a second trial, the safety and immunogenicity of the vaccine containing CFE from all three strains of S. uberis and Emulsigen-D was determined in dairy cows. A group of six cows were vaccinated subcutaneously at 3 and 1 week prior to dry off and revaccinated 2-3 weeks before calving. Immune responses in blood and mammary gland secretions (MGS) were monitored during the dry period and in the subsequent lactation. The vaccine was well tolerated with no adverse effect from vaccination observed in any of the cows. Vaccination induced an antigen-specific cytotoxic effect against blood monocytes/macrophages that had phagocytosed S. uberis, moderate antigen-specific IFN-γ responses in blood and strong antibody responses in both blood and MGS. In conclusion, the results

  11. Subcomponent vaccine based on CTA1-DD adjuvant with incorporated UreB class II peptides stimulates protective Helicobacter pylori immunity.

    Science.gov (United States)

    Nedrud, John G; Bagheri, Nayer; Schön, Karin; Xin, Wei; Bergroth, Hilda; Eliasson, Dubravka Grdic; Lycke, Nils Y

    2013-01-01

    A mucosal vaccine against Helicobacter pylori infection could help prevent gastric cancers and peptic ulcers. While previous attempts to develop such a vaccine have largely failed because of the requirement for safe and effective adjuvants or large amounts of well defined antigens, we have taken a unique approach to combining our strong mucosal CTA1-DD adjuvant with selected peptides from urease B (UreB). The protective efficacy of the selected peptides together with cholera toxin (CT) was first confirmed. However, CT is a strong adjuvant that unfortunately is precluded from clinical use because of its toxicity. To circumvent this problem we have developed a derivative of CT, the CTA1-DD adjuvant, that has been found safe in non-human primates and equally effective compared to CT when used intranasally. We genetically fused the selected peptides into the CTA1-DD plasmid and found after intranasal immunizations of Balb/c mice using purified CTA1-DD with 3 copies of an H. pylori urease T cell epitope (CTA1-UreB3T-DD) that significant protection was stimulated against a live challenge infection. Protection was, however, weaker than with the gold standard, bacterial lysate+CT, but considering that we only used a single epitope in nanomolar amounts the results convey optimism. Protection was associated with enhanced Th1 and Th17 immunity, but immunizations in IL-17A-deficient mice revealed that IL-17 may not be essential for protection. Taken together, we have provided evidence for the rational design of an effective mucosal subcomponent vaccine against H. pylori infection based on well selected protective epitopes from relevant antigens incorporated into the CTA1-DD adjuvant platform.

  12. Subcomponent vaccine based on CTA1-DD adjuvant with incorporated UreB class II peptides stimulates protective Helicobacter pylori immunity.

    Directory of Open Access Journals (Sweden)

    John G Nedrud

    Full Text Available A mucosal vaccine against Helicobacter pylori infection could help prevent gastric cancers and peptic ulcers. While previous attempts to develop such a vaccine have largely failed because of the requirement for safe and effective adjuvants or large amounts of well defined antigens, we have taken a unique approach to combining our strong mucosal CTA1-DD adjuvant with selected peptides from urease B (UreB. The protective efficacy of the selected peptides together with cholera toxin (CT was first confirmed. However, CT is a strong adjuvant that unfortunately is precluded from clinical use because of its toxicity. To circumvent this problem we have developed a derivative of CT, the CTA1-DD adjuvant, that has been found safe in non-human primates and equally effective compared to CT when used intranasally. We genetically fused the selected peptides into the CTA1-DD plasmid and found after intranasal immunizations of Balb/c mice using purified CTA1-DD with 3 copies of an H. pylori urease T cell epitope (CTA1-UreB3T-DD that significant protection was stimulated against a live challenge infection. Protection was, however, weaker than with the gold standard, bacterial lysate+CT, but considering that we only used a single epitope in nanomolar amounts the results convey optimism. Protection was associated with enhanced Th1 and Th17 immunity, but immunizations in IL-17A-deficient mice revealed that IL-17 may not be essential for protection. Taken together, we have provided evidence for the rational design of an effective mucosal subcomponent vaccine against H. pylori infection based on well selected protective epitopes from relevant antigens incorporated into the CTA1-DD adjuvant platform.

  13. Oral delivery of human biopharmaceuticals, autoantigens and vaccine antigens bioencapsulated in plant cells.

    Science.gov (United States)

    Kwon, Kwang-Chul; Verma, Dheeraj; Singh, Nameirakpam D; Herzog, Roland; Daniell, Henry

    2013-06-15

    Among 12billion injections administered annually, unsafe delivery leads to >20million infections and >100million reactions. In an emerging new concept, freeze-dried plant cells (lettuce) expressing vaccine antigens/biopharmaceuticals are protected in the stomach from acids/enzymes but are released to the immune or blood circulatory system when plant cell walls are digested by microbes that colonize the gut. Vaccine antigens bioencapsulated in plant cells upon oral delivery after priming, conferred both mucosal and systemic immunity and protection against bacterial, viral or protozoan pathogens or toxin challenge. Oral delivery of autoantigens was effective against complications of type 1 diabetes and hemophilia, by developing tolerance. Oral delivery of proinsulin or exendin-4 expressed in plant cells regulated blood glucose levels similar to injections. Therefore, this new platform offers a low cost alternative to deliver different therapeutic proteins to combat infectious or inherited diseases by eliminating inactivated pathogens, expensive purification, cold storage/transportation and sterile injections. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Cutting edge: HLA-B27 acquires many N-terminal dibasic peptides: coupling cytosolic peptide stability to antigen presentation

    NARCIS (Netherlands)

    Herberts, Carla A.; Neijssen, Joost J.; de Haan, Jolanda; Janssen, Lennert; Drijfhout, Jan Wouter; Reits, Eric A.; Neefjes, Jacques J.

    2006-01-01

    Ag presentation by MHC class I is a highly inefficient process because cytosolic peptidases destroy most peptides after proteasomal generation. Various mechanisms shape the MHC class I peptidome. We define a new one: intracellular peptide stability. Peptides with two N-terminal basic amino acids are

  15. Antigen-displaying lipid-enveloped PLGA nanoparticles as delivery agents for a Plasmodium vivax malaria vaccine.

    Science.gov (United States)

    Moon, James J; Suh, Heikyung; Polhemus, Mark E; Ockenhouse, Christian F; Yadava, Anjali; Irvine, Darrell J

    2012-01-01

    The parasite Plasmodium vivax is the most frequent cause of malaria outside of sub-Saharan Africa, but efforts to develop viable vaccines against P. vivax so far have been inadequate. We recently developed pathogen-mimicking polymeric vaccine nanoparticles composed of the FDA-approved biodegradable polymer poly(lactide-co-glycolide) acid (PLGA) "enveloped" by a lipid membrane. In this study, we sought to determine whether this vaccine delivery platform could be applied to enhance the immune response against P. vivax sporozoites. A candidate malaria antigen, VMP001, was conjugated to the lipid membrane of the particles, and an immunostimulatory molecule, monophosphoryl lipid A (MPLA), was incorporated into the lipid membranes, creating pathogen-mimicking nanoparticle vaccines (VMP001-NPs). Vaccination with VMP001-NPs promoted germinal center formation and elicited durable antigen-specific antibodies with significantly higher titers and more balanced Th1/Th2 responses in vivo, compared with vaccines composed of soluble protein mixed with MPLA. Antibodies raised by NP vaccinations also exhibited enhanced avidity and affinity toward the domains within the circumsporozoite protein implicated in protection and were able to agglutinate live P. vivax sporozoites. These results demonstrate that these VMP001-NPs are promising vaccines candidates that may elicit protective immunity against P. vivax sporozoites.

  16. Antigen-displaying lipid-enveloped PLGA nanoparticles as delivery agents for a Plasmodium vivax malaria vaccine.

    Directory of Open Access Journals (Sweden)

    James J Moon

    Full Text Available The parasite Plasmodium vivax is the most frequent cause of malaria outside of sub-Saharan Africa, but efforts to develop viable vaccines against P. vivax so far have been inadequate. We recently developed pathogen-mimicking polymeric vaccine nanoparticles composed of the FDA-approved biodegradable polymer poly(lactide-co-glycolide acid (PLGA "enveloped" by a lipid membrane. In this study, we sought to determine whether this vaccine delivery platform could be applied to enhance the immune response against P. vivax sporozoites. A candidate malaria antigen, VMP001, was conjugated to the lipid membrane of the particles, and an immunostimulatory molecule, monophosphoryl lipid A (MPLA, was incorporated into the lipid membranes, creating pathogen-mimicking nanoparticle vaccines (VMP001-NPs. Vaccination with VMP001-NPs promoted germinal center formation and elicited durable antigen-specific antibodies with significantly higher titers and more balanced Th1/Th2 responses in vivo, compared with vaccines composed of soluble protein mixed with MPLA. Antibodies raised by NP vaccinations also exhibited enhanced avidity and affinity toward the domains within the circumsporozoite protein implicated in protection and were able to agglutinate live P. vivax sporozoites. These results demonstrate that these VMP001-NPs are promising vaccines candidates that may elicit protective immunity against P. vivax sporozoites.

  17. Label-free quantitative mass spectrometry for analysis of protein antigens in a meningococcal group B outer membrane vesicle vaccine.

    Science.gov (United States)

    Dick, Lawrence W; Mehl, John T; Loughney, John W; Mach, Anna; Rustandi, Richard R; Ha, Sha; Zhang, Lan; Przysiecki, Craig T; Dieter, Lance; Hoang, Van M

    2015-01-01

    The development of a multivalent outer membrane vesicle (OMV) vaccine where each strain contributes multiple key protein antigens presents numerous analytical challenges. One major difficulty is the ability to accurately and specifically quantitate each antigen, especially during early development and process optimization when immunoreagents are limited or unavailable. To overcome this problem, quantitative mass spectrometry methods can be used. In place of traditional mass assays such as enzyme-linked immunosorbent assays (ELISAs), quantitative LC-MS/MS using multiple reaction monitoring (MRM) can be used during early-phase process development to measure key protein components in complex vaccines in the absence of specific immunoreagents. Multiplexed, label-free quantitative mass spectrometry methods using protein extraction by either detergent or 2-phase solvent were developed to quantitate levels of several meningococcal serogroup B protein antigens in an OMV vaccine candidate. Precision was demonstrated to be less than 15% RSD for the 2-phase extraction and less than 10% RSD for the detergent extraction method. Accuracy was 70 to 130% for the method using a 2-phase extraction and 90-110% for detergent extraction. The viability of MS-based protein quantification as a vaccine characterization method was demonstrated and advantages over traditional quantitative methods were evaluated. Implementation of these MS-based quantification methods can help to decrease the development time for complex vaccines and can provide orthogonal confirmation of results from existing antigen quantification techniques.

  18. Effect of different hapten-carrier conjugation ratios and molecular orientations on antibody affinity against a peptide antigen

    DEFF Research Database (Denmark)

    Pedersen, M. K.; Sørensen, Nanna Skall; Heegaard, Peter M. H.

    2006-01-01

    -based assay systems and in deciding whether a vaccine-induced antibody response will be protective. With ovalbumin as a carrier protein and a peptide (7.2NY) representing a 19 ammo acid sequence from the E. coli-derived Verotoxin 2e as a model hapten we investigated whether it was possible to influence...... ten dines at two-weeks intervals with low doses of the eight conjugates, Blood samples collected between each immunisation were analysed by ELISA for specific antibody titres and relative affinities. With both types of conjugations, the anti-peptide antibody titres increased in response to increasing...... for terminal conjugation. Thus, it appears that the molar ratio of a peptide and its carrier may affect the resulting antibody affinities, and that a conjugation ratio between a terminally Conjugated peptide and its carrier approaching one will result in relatively high antibody affinities. Furthermore...

  19. Heterologous expression of carcinoembryonic antigen in Lactococcus lactis via LcsB-mediated surface displaying system for oral vaccine development.

    Science.gov (United States)

    Zhang, Xiaowei; Hu, Shumin; Du, Xue; Li, Tiejun; Han, Lanlan; Kong, Jian

    2016-12-01

    Carcinoembryonic antigen (CEA) is an attractive target for immunotherapy because it is expressed minimally in normal tissue, but is overexpressed in a wide variety of malignant epithelial tissues. Lactic acid bacteria (LABs), widely used in food processes, are attractive candidates for oral vaccination. Thus, we examined whether LABs could be used as a live vaccine vector to deliver CEA antigen. CEA was cloned into an Escherichia coli/Lactococcus lactis shuttle vector pSEC:LEISS under the control of a nisin promoter. For displaying the CEA on the cell surface of the L. lactis strain, the anchor motif LcsB from the S-layer protein of Lactobacillus crispatus was fused with CEA. Intracellular and cell surface expression of the CEA-LcsB fusion was confirmed by western blot analysis. Significantly higher levels of CEA-specific secretory immunoglobulin A in the sera of mice were observed upon oral administration of strain cultures containing the CEA-LcsB fused protein. In addition, the CEA-LcsB antigen group showed a higher spleen index compared to the CEA antigen alone or negative control, demonstrating that surface-displayed CEA antigen could induce a higher immune response. These results provided the first evidence for displaying CEA antigen on the cell surfaces of LABs as oral vaccines against cancer or infectious diseases. Copyright © 2014. Published by Elsevier B.V.

  20. Enhanced stability of a chimeric hepatitis B core antigen virus-like-particle (HBcAg-VLP) by a C-terminal linker-hexahistidine-peptide.

    Science.gov (United States)

    Schumacher, Jens; Bacic, Tijana; Staritzbichler, René; Daneschdar, Matin; Klamp, Thorsten; Arnold, Philipp; Jägle, Sabrina; Türeci, Özlem; Markl, Jürgen; Sahin, Ugur

    2018-04-13

    Virus-like-particles (VLPs) are attractive nanoparticulate scaffolds for broad applications in material/biological sciences and medicine. Prior their functionalization, specific adaptations have to be carried out. These adjustments frequently lead to disordered particles, but the particle integrity is an essential factor for the VLP suitability. Therefore, major requirements for particle stabilization exist. The objective of this study was to evaluate novel stabilizing elements for functionalized chimeric hepatitis B virus core antigen virus-like particles (HBcAg-VLP), with beneficial characteristics for vaccine development, imaging or delivery. The effects of a carboxy-terminal polyhistidine-peptide and an intradimer disulfide-bridge on the stability of preclinically approved chimeric HBcAg-VLPs were assessed. We purified recombinant chimeric HBcAg-VLPs bearing different modified C-termini and compared their physical and chemical particle stability by quantitative protein-biochemical and biophysical techniques. We observed lower chemical resistance of T = 3- compared to T = 4-VLP (triangulation number) capsids and profound impairment of accessibility of hexahistidine-peptides in assembled VLPs. Histidines attached to the C-terminus were associated with superior mechanical and/or chemical particle stability depending on the number of histidine moieties. A molecular modeling approach based on cryo-electron microscopy and biolayer interferometry revealed the underlying structural mechanism for the strengthening of the integrity of VLPs. Interactions triggering capsid stabilization occur on a highly conserved residue on the basis of HBcAg-monomers as well as on hexahistidine-peptides of adjacent monomers. This new stabilization mechanism appears to mimic an evolutionary conserved stabilization concept for hepadnavirus core proteins. These findings establish the genetically simply transferable C-terminal polyhistidine-peptide as a general stabilizing element

  1. Protection against Fasciola gigantica using paramyosin antigen as a candidate for vaccine production.

    Science.gov (United States)

    Abou-Elhakam, H; Rabee, I; El Deeb, S; El Amir, A

    2013-11-15

    Yet no vaccine to protect ruminants against liver fluke infection has been commercialized. In an attempt to develop a suitable vaccine against Fasciola gigantica (F. gigantica) infection in rabbits, using 97 kDa Pmy antigen. It was found that, the mean worm burdens and bile egg count after challenge were reduced significantly by 58.40 and 61.40%, respectively. On the other hand, immunization of rabbits with Pmy induced a significant expression of humoral antibodies (IgM, total IgG, IgG1, IgG2 and IgG4) and different cytokines (IL-6, IL-10, L-12 and TNF-alpha). Among Ig isotypes, IgG2 and IgG4 were most dominant Post-infection (PI) while, recording a low IgG1 level. The dominance of IgG2 and IgG4 suggested late T helper1 (Th1) involvement in rabbit's cellular response. While, the low IgG1 level suggested Th2 response to adult F. gigantica worm Pmy. Among all cytokines, IL-10 was the highest in rabbits immunized with Pmy PI suggesting also the enhancement of Th2 response. It was clear that the native F. gigantica Pmy is considered as a relevant candidate for vaccination against fascioliasis. Also, these data suggested the immunoprophylactic effect of the native F. gigantica Pmy which is mediated by a mixed Th1/Th2 response.

  2. Preclinical evaluation of multi antigenic HCV DNA vaccine for the prevention of Hepatitis C virus infection.

    Science.gov (United States)

    Lee, Hyojin; Jeong, Moonsup; Oh, Jooyeon; Cho, Youngran; Shen, Xuefei; Stone, John; Yan, Jian; Rothkopf, Zachary; Khan, Amir S; Cho, Byung Mun; Park, Young K; Weiner, David B; Son, Woo-Chan; Maslow, Joel N

    2017-03-07

    Direct-acting antiviral treatment for hepatitis C virus (HCV) infection is costly and does not protect from re-infection. For human and chimpanzees, recovery from acute HCV infection correlates with host CD4+ and CD8+ T cell responses. DNA plasmids targeting the HCV non-structural antigens NS3, NS4, and NS5, were previously reported to induce robust and sustained T cell responses in mice and primates. These plasmids were combined with a plasmid encoding cytokine IL-28B, together named as VGX-6150. The dose-dependent T cell response and safety of VGX-6150 administered intramuscularly and followed by electroporation was assessed in mice. Immune responses plateaued at 20 μg/dose with IL-28B demonstrating significant immunoadjuvant activity. Mice administered VGX-6150 at 40, 400, and 800 μg given either as a single injection or as 14 injections given bi-weekly over 26 weeks showed no vaccine related changes in any clinical parameter compared to placebo recipients. There was no evidence of VGX-6150 accumulation at the injection site or in any organ 1 month following the 14 th vaccination. Based on these studies, the approximate lethal dose (ALD) exceeds 800 μg/dose and the NOAEL was 800 μg/dose in mouse. In conclusion, VGX-6150 appears safe and a promising preventive vaccine candidate for HCV infection.

  3. CD4+ T-cell Responses Among Adults and Young Children In Response to Streptococcus pneumoniae and Haemophilus influenzae Vaccine Candidate Protein Antigens

    OpenAIRE

    Sharma, Sharad K.; Roumanes, David; Almudevar, Anthony; Mosmann, Tim R.; Pichichero, Michael E.

    2013-01-01

    We characterized cytokine profiles of CD4+ T-helper (h) cells in adults and young children to ascertain if responses occur to next-generation candidate vaccine antigens PspA, PcpA, PhtD, PhtE, Ply, LytB of Streptococcus pneumonia (Spn) and Protein D and OMP26 of non-typeable Haemophilus influenzae (NTHi). Adults had vaccine antigen-specific Th1 - and Th2 cells responsive to all antigens evaluated whereas young children had significant numbers of vaccine antigen-specific CD4+ T cells producing...

  4. Peptide-based anti-PCSK9 vaccines - an approach for long-term LDLc management.

    Directory of Open Access Journals (Sweden)

    Gergana Galabova

    Full Text Available Low Density Lipoprotein (LDL hypercholesterolemia, and its associated cardiovascular diseases, are some of the leading causes of death worldwide. The ability of proprotein convertase subtilisin/kexin 9 (PCSK9 to modulate circulating LDL cholesterol (LDLc concentrations made it a very attractive target for LDLc management. To date, the most advanced approaches for PCSK9 inhibition are monoclonal antibody (mAb therapies. Although shown to lower LDLc significantly, mAbs face functional limitations because of their relatively short in vivo half-lives necessitating frequent administration. Here, we evaluated the long-term efficacy and safety of PCSK9-specific active vaccines in different preclinical models.PCSK9 peptide-based vaccines were successfully selected by our proprietary technology. To test their efficacy, wild-type (wt mice, Ldlr+/- mice, and rats were immunized with highly immunogenic vaccine candidates. Vaccines induced generation of high-affine PCSK9-specific antibodies in all species. Group mean total cholesterol (TC concentration was reduced by up to 30%, and LDLc up to 50% in treated animals. Moreover, the PCSK9 vaccine-induced humoral immune response persisted for up to one year in mice, and reduced cholesterol levels significantly throughout the study. Finally, the vaccines were well tolerated in all species tested.Peptide-based anti-PCSK9 vaccines induce the generation of antibodies that are persistent, high-affine, and functional for up to one year. They are powerful and safe tools for long-term LDLc management, and thus may represent a novel therapeutic approach for the prevention and/or treatment of LDL hypercholesterolemia-related cardiovascular diseases in humans.

  5. Hepatitis B vaccination coverage and risk factors associated with incomplete vaccination of children born to hepatitis B surface antigen-positive mothers, Denmark, 2006 to 2010.

    Science.gov (United States)

    Kunoee, Asja; Nielsen, Jens; Cowan, Susan

    2016-01-01

    In Denmark, universal screening of pregnant women for hepatitis B has been in place since November 2005, with the first two years as a trial period with enhanced surveillance. It is unknown what the change to universal screening without enhanced surveillance has meant for vaccination coverage among children born to hepatitis B surface antigen (HBsAg)-positive mothers and what risk factors exist for incomplete vaccination. This retrospective cohort study included 699 children of mothers positive for HBsAg. Information on vaccination and risk factors was collected from central registers. In total, 93% (651/699) of the children were vaccinated within 48 hours of birth, with considerable variation between birthplaces. Only 64% (306/475) of the children had received all four vaccinations through their general practitioner (GP) at the age of two years, and 10% (47/475) of the children had received no hepatitis B vaccinations at all. Enhanced surveillance was correlated positively with coverage of birth vaccination but not with coverage at the GP. No or few prenatal examinations were a risk factor for incomplete vaccination at the GP. Maternity wards and GPs are encouraged to revise their vaccination procedures and routines for pregnant women, mothers with chronic HBV infection and their children.

  6. Large-scale detection of antigen-specific T cells using peptide-MHC-I multimers labeled with DNA barcodes

    DEFF Research Database (Denmark)

    Bentzen, Amalie Kai; Marquard, Andrea Marion; Lyngaa, Rikke Birgitte

    2016-01-01

    -major histocompatibility complex (MHC) multimers labeled with individual DNA barcodes to screen >1,000 peptide specificities in a single sample, and detect low-frequency CD8 T cells specific for virus- or cancer-restricted antigens. When analyzing T-cell recognition of shared melanoma antigens before and after adoptive...... cell therapy in melanoma patients, we observe a greater number of melanoma-specific T-cell populations compared with cytometry-based approaches. Furthermore, we detect neoepitope-specific T cells in tumor-infiltrating lymphocytes and peripheral blood from patients with non-small cell lung cancer...

  7. Structural Simulation of MHC-peptide Interactions using T-cell Epitope in Iron-acquisition Protein of N. meningitides for Vaccine Design

    Directory of Open Access Journals (Sweden)

    Namrata Mishra

    2010-12-01

    Full Text Available The present work uses a structural simulation approach to identify the potential target vaccine candidates or T cell epitopes (antigenic region that can activate T cell response in two iron acquisition proteins from Neisseria. An iron regulated outer membrane protein frpB: extracellular, [NMB1988], and a Major ferric Iron-binding protein fbpA: periplasmic, [NMB0634] critical for the survival of the pathogen in the host were used. Ten novel promiscuous epitopes from the two iron acquisition proteins were identified using bioinformatics interface. Of these epitopes, 630VQKAVGSIL638 present on frpB with high binding affinity for allele HLA*DR1 was identified with an anchor position at P2, an aliphatic residue at P4 and glycine at P6 making it thereby a potential quality choice for linking peptide-loaded MHC dynamics to T-cell activation and vaccine constructs. The feasibility and structural binding of predicted peptide to the respective HLA allele was investigated by molecular modeling and template-based structural simulation. The conformational properties of the linear peptide were investigated by molecular dynamics using GROMOS96 package and Swiss PDB viewer.

  8. Predicted MHC peptide binding promiscuity explains MHC class I 'hotspots' of antigen presentation defined by mass spectrometry eluted ligand data.

    Science.gov (United States)

    Jappe, Emma Christine; Kringelum, Jens; Trolle, Thomas; Nielsen, Morten

    2018-02-15

    Peptides that bind to and are presented by MHC class I and class II molecules collectively make up the immunopeptidome. In the context of vaccine development, an understanding of the immunopeptidome is essential, and much effort has been dedicated to its accurate and cost-effective identification. Current state-of-the-art methods mainly comprise in silico tools for predicting MHC binding, which is strongly correlated with peptide immunogenicity. However, only a small proportion of the peptides that bind to MHC molecules are, in fact, immunogenic, and substantial work has been dedicated to uncovering additional determinants of peptide immunogenicity. In this context, and in light of recent advancements in mass spectrometry (MS), the existence of immunological hotspots has been given new life, inciting the hypothesis that hotspots are associated with MHC class I peptide immunogenicity. We here introduce a precise terminology for defining these hotspots and carry out a systematic analysis of MS and in silico predicted hotspots. We find that hotspots defined from MS data are largely captured by peptide binding predictions, enabling their replication in silico. This leads us to conclude that hotspots, to a great degree, are simply a result of promiscuous HLA binding, which disproves the hypothesis that the identification of hotspots provides novel information in the context of immunogenic peptide prediction. Furthermore, our analyses demonstrate that the signal of ligand processing, although present in the MS data, has very low predictive power to discriminate between MS and in silico defined hotspots. © 2018 John Wiley & Sons Ltd.

  9. Cytotoxic T lymphocyte response to peptide vaccination predicts survival in stage III colorectal cancer.

    Science.gov (United States)

    Kawamura, Junichiro; Sugiura, Fumiaki; Sukegawa, Yasushi; Yoshioka, Yasumasa; Hida, Jin-Ichi; Hazama, Shoichi; Okuno, Kiyotaka

    2018-02-23

    We previously reported a phase I clinical trial of a peptide vaccine ring finger protein 43 (RNF43) and 34-kDa translocase of the outer mitochondrial membrane (TOMM34) combined with uracil-tegafur (UFT)/LV for patients with metastatic colorectal cancer (CRC), and demonstrated the safety and immunological responsiveness of this combination therapy. In this study, we evaluated vaccination-induced immune responses to clarify the survival benefit of the combination therapy as adjuvant treatment. We enrolled 44 patients initially in an HLA-masked fashion. After the disclosure of HLA, 28 patients were in the HLA-A*2402-matched and 16 were in the unmatched group. In the HLA-matched group, 14 patients had positive CTL responses specific for the RNF43 and/or TOMM34 peptides after 2 cycles of treatment and 9 had negative responses; in the HLA-unmatched group, 10 CTL responses were positive and 2 negative. In the HLA-matched group, 3-year relapse-free survival (RFS) was significantly better in the positive CTL subgroup than in the negative-response subgroup. Patients with negative vaccination-induced CTL responses showed a significant trend towards shorter RFS than those with positive responses. Moreover, in the HLA-unmatched group, the positive CTL response subgroup showed an equally good 3-year RFS as in the HLA-matched group. In conclusion, vaccination-induced CTL response to peptide vaccination could predict survival in the adjuvant setting for stage III CRC. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  10. Feasibility of Cancer Immunotherapy with WT1 Peptide Vaccination for Solid and Hematological Malignancies in Children.

    Science.gov (United States)

    Sawada, Akihisa; Inoue, Masami; Kondo, Osamu; Yamada-Nakata, Kayo; Ishihara, Takashi; Kuwae, Yuko; Nishikawa, Masanori; Ammori, Yasuhiro; Tsuboi, Akihiro; Oji, Yusuke; Koyama-Sato, Maho; Oka, Yoshihiro; Yasui, Masahiro; Sugiyama, Haruo; Kawa, Keisei

    2016-02-01

    Advances in cancer immunotherapy in the pediatric field are needed in order to improve the prognosis of children with malignancies. We conducted a prospective phase I/II study of WT1 peptide vaccination for children with relapsed or refractory malignancies. The main eligibility criteria were affected tissues or leukemic cells expressing the WT1 gene, and patients (and donors for allogeneic hematopoietic stem cell transplantation) having HLA-A*24:02. Vaccination using the WT1 peptide (CYTWNQMNL), which was modified for higher affinity to this HLA-type molecule with the adjuvant Montanide ISA51, was performed weekly 12 times. Twenty-six patients were enrolled and 13 (50.0%) completed the vaccination 12 times. Evidence for the induction of WT1-specific cytotoxic T-lymphocyte (CTL) responses without severe systemic side effects was obtained. Two out of 12 patients with bulky disease exhibited a transient clinical effect (one mixed response and one stable disease), three out of six patients with minimal residual disease achieved transient molecular remission, and five out of eight patients without a detectable level of the molecular marker, but with a high risk of relapse, had the best outcome of long-term continuous complete remission. WT1 vaccination is a safe immunotherapy and induced WT1-specific CTL responses in children; however, as a single agent, vaccination only provided patients in remission, but with a high risk of relapse, with "long-term benefits" in the context of its use for relapse prevention. WT1 peptide-based treatments in combination with other modalities, such as anti-tumor drugs or immunomodulating agents, need to be planned. © 2015 Wiley Periodicals, Inc.

  11. Efficacy of a DNA Vaccine Carrying Eimeria maxima Gam56 Antigen Gene against Coccidiosis in Chickens

    Science.gov (United States)

    Xu, Jinjun; Zhang, Yan

    2013-01-01

    To control coccidiosis without using prophylactic medications, a DNA vaccine targeting the gametophyte antigen Gam56 from Eimeria maxima in chickens was constructed, and the immunogenicity and protective effects were evaluated. The ORF of Gam56 gene was cloned into an eukaryotic expression vector pcDNA3.1(zeo)+. Expression of Gam56 protein in COS-7 cells transfected with recombinant plasmid pcDNA-Gam56 was confirmed by indirect immunofluorescence assay. The DNA vaccine was injected intramuscularly to yellow feathered broilers of 1-week old at 3 dosages (25, 50, and 100 µg/chick). Injection was repeated once 1 week later. One week after the second injection, birds were challenged orally with 5×104 sporulated oocysts of E. maxima, then weighed and killed at day 8 post challenge. Blood samples were collected and examined for specific peripheral blood lymphocyte proliferation activity and serum antibody levels. Compared with control groups, the administration of pcDNA-Gam56 vaccine markedly increased the lymphocyte proliferation activity (P<0.05) at day 7 and 14 after the first immunization. The level of lymphocyte proliferation started to decrease on day 21 after the first immunization. A similar trend was seen in specific antibody levels. Among the 3 pcDNA-Gam56 immunized groups, the median dosage group displayed the highest lymphocyte proliferation and antibody levels (P<0.05). The median dosage group had the greatest relative body weight gain (89.7%), and the greatest oocyst shedding reduction (53.7%). These results indicate that median dosage of DNA vaccine had good immunogenicity and immune protection effects, and may be used in field applications for coccidiosis control. PMID:23710081

  12. Polyclonal immune responses to antigens associated with cancer signaling pathways and new strategies to enhance cancer vaccines.

    Science.gov (United States)

    Clay, Timothy M; Osada, Takuya; Hartman, Zachary C; Hobeika, Amy; Devi, Gayathri; Morse, Michael A; Lyerly, H Kim

    2011-04-01

    Aberrant signaling pathways are a hallmark of cancer. A variety of strategies for inhibiting signaling pathways have been developed, but monoclonal antibodies against receptor tyrosine kinases have been among the most successful. A challenge for these therapies is therapeutic unresponsiveness and acquired resistance due to mutations in the receptors, upregulation of alternate growth and survival pathways, or inadequate function of the monoclonal antibodies. Vaccines are able to induce polyclonal responses that can have a multitude of affects against the target molecule. We began to explore therapeutic vaccine development to antigens associated with these signaling pathways. We provide an illustrative example in developing therapeutic cancer vaccines inducing polyclonal adaptive immune responses targeting the ErbB family member HER2. Further, we will discuss new strategies to augment the clinical efficacy of cancer vaccines by enhancing vaccine immunogenicity and reversing the immunosuppressive tumor microenvironment.

  13. Vaccination with peptides of Mycobacterium avium subsp. paratuberculosis (MAP) reduces MAP burden of infected goats

    DEFF Research Database (Denmark)

    Melvang, Heidi Mikkelsen; Hassan, Sufia Butt; Thakur, Aneesh

    Mycobacterium avium subsp. paratuberculosis (Map) is the cause of paratuberculosis, a chronic enteritis of ruminants that is widespread worldwide. We investigated the effect of post-exposure vaccination with Map specific peptides in a goat model aiming at developing a Map vaccine that will neither...... unique to Map from selected proteins (n =68). For vaccination, 23 MAP peptides (20 µg each) were selected and formulated with Montanide ISA 61 VG adjuvant. At age three weeks 10 goats were orally inoculated with 4x10E9 live Map and assigned to two groups of 5 goats each: 5 vaccinated (V) at 14 and 18...... weeks post inoculation (PI) and 5 unvaccinated (C). At termination 32 weeks PI, Map burdens in 15 intestinal tissues and lymph nodes were determined by IS900 qPCR. Of the 75 tissue samples from the 5 C goats only 5 samples were IS900 qPCR negative. In contrast, only 9 samples in total from 5 V goats...

  14. Improved protection conferred by vaccination with a recombinant vaccinia virus that incorporates a foreign antigen into the extracellular enveloped virion

    International Nuclear Information System (INIS)

    Kwak, Heesun; Mustafa, Waleed; Speirs, Kendra; Abdool, Asha J.; Paterson, Yvonne; Isaacs, Stuart N.

    2004-01-01

    Recombinant poxviruses have shown promise as vaccine vectors. We hypothesized that improved cellular immune responses could be developed to a foreign antigen by incorporating it as part of the extracellular enveloped virion (EEV). We therefore constructed a recombinant vaccinia virus that replaced the cytoplasmic domain of the B5R protein with a test antigen, HIV-1 Gag. Mice immunized with the virus expressing Gag fused to B5R had significantly better primary CD4 T-cell responses than recombinant virus expressing HIV-Gag from the TK-locus. The CD8 T-cell responses were less different between the two groups. Importantly, although we saw differences in the immune response to the test antigen, the vaccinia virus-specific immune responses were similar with both constructs. When groups of vaccinated mice were challenged 30 days later with a recombinant Listeria monocytogenes that expresses HIV-Gag, mice inoculated with the virus that expresses the B5R-Gag fusion protein had lower colony counts of Listeria in the liver and spleen than mice vaccinated with the standard recombinant. Thus, vaccinia virus expressing foreign antigen incorporated into EEV may be a better vaccine strategy than standard recombinant vaccinia virus

  15. Development of a Nucleoprotein-Based Enzyme-Linked Immunosorbent Assay Using a Synthetic Peptide Antigen for Detection of Avian Metapneumovirus Antibodies in Turkey Sera

    Science.gov (United States)

    Alvarez, Rene; Njenga, M. Kariuki; Scott, Melissa; Seal, Bruce S.

    2004-01-01

    Avian metapneumoviruses (aMPV) cause an upper respiratory tract disease with low mortality but high morbidity, primarily in commercial turkeys, that can be exacerbated by secondary infections. There are three types of aMPV, of which type C is found only in the United States. The aMPV nucleoprotein (N) amino acid sequences of serotypes A, B, and C were aligned for comparative analysis. On the basis of the predicted antigenicity of consensus sequences, five aMPV-specific N peptides were synthesized for development of a peptide antigen enzyme-linked immunosorbent assay (aMPV N peptide-based ELISA) to detect aMPV-specific antibodies among turkeys. Sera from naturally and experimentally infected turkeys were used to demonstrate the presence of antibodies reactive to the chemically synthesized aMPV N peptides. Subsequently, aMPV N peptide 1, which had the sequence 10-DLSYKHAILKESQYTIKRDV-29, with variations at only three amino acids among aMPV serotypes, was evaluated as a universal aMPV ELISA antigen. Data obtained with the peptide-based ELISA correlated positively with total aMPV viral antigen-based ELISAs, and the peptide ELISA provided higher optical density readings. The results indicated that aMPV N peptide 1 can be used as a universal ELISA antigen to detect antibodies for all aMPV serotypes. PMID:15013970

  16. Mimicry of the immunodominant conformation-dependent antigenic site of hepatitis A virus by motifs selected from synthetic peptide libraries.

    Science.gov (United States)

    Mattioli, S; Imberti, L; Stellini, R; Primi, D

    1995-09-01

    Hepatitis A virus (HAV) is a positive-strand RNA virus with a genome length of approximately 7,480 nucleotides. Although HAV morphogenesis is thought to be similar to that of poliovirus, the prototype picornavirus, the complete characterization of the antigenic structure of this virus remains elusive. All the available evidences, however, support the existence, on HAV virions and empty capsids, of an immunodominant neutralization antigenic site which is conformation dependent and whose structure involves residues of both VP1 and VP3 capsid proteins. This particular feature and the difficulty of obtaining high virus yield in tissue cultures make HAV an ideal target for developing synthetic peptides that simulate the structure of its main antigenic determinant. To this end we utilized, in the present work, the divide-couple-recombine approach to generate a random library composed of millions of different hexapeptides. This vast library was screened with a well-characterized anti-HAV monoclonal antibody. By this strategy we identified a peptide that reacted specifically with monoclonal and polyclonal anti-HAV antibodies and, in mice, induced a specific anti-virus immune response. Furthermore, the peptide could also be used in an enzyme-linked immunosorbent assay for revealing a primary immunoglobulin M immune response in sera of acutely infected human patients. Interestingly, no sequence homology was found between the identified peptide and the HAV capsid proteins VP1 and VP3. Collectively, these data represent an additional important paradigm of a mimotope capable of mimicking an antigenic determinant with unknown tertiary structure.

  17. Cancer Antigen Prioritization: A Road Map to Work in Defining Vaccines Against Specific Targets. A Point of View

    International Nuclear Information System (INIS)

    Gomez, Daniel E.; Vázquez, Ana María; Alonso, Daniel F.

    2012-01-01

    The use of anti-idiotype antibodies as vaccines to stimulate antitumor immunity is a very promising pathway in the therapy of cancer. A good body of work in animal tumor models have demonstrated the efficacy of anti-Id vaccines in preventing tumor growth and curing mice with established tumors. A number of monoclonal anti-Id antibodies that mimic different human tumor-associated antigens (TAAs) have been developed and tested in the clinic, demonstrating interesting. In general terms, the antigen mimicry by anti-Id antibodies has reflected structural homology in the most of the cases, and amino acid sequence homology in a minority of them. The major challenge of immunotherapy using anti-idiotype vaccines is to identify the optimal anti-idiotype antibody that will function as a true surrogate antigen for a TAA system, and ideally will generate both humoral and cellular immune responses. Several clinical studies have shown enhanced patient's survival when receiving anti-Id vaccines, the true demonstration of efficacy of these vaccines will depend upon the results of several randomized Phase III clinical trials that are currently planned or ongoing (Bhattacharya-Chatterjee et al.,).

  18. Cancer Antigen Prioritization: A Road Map to Work in Defining Vaccines Against Specific Targets. A Point of View

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Daniel E. [Laboratory of Molecular Oncology, Quilmes National University, Buenos Aires (Argentina); Vázquez, Ana María [Center of Molecular Immunology, La Habana (Cuba); Alonso, Daniel F., E-mail: degomez@unq.edu.ar [Laboratory of Molecular Oncology, Quilmes National University, Buenos Aires (Argentina)

    2012-06-28

    The use of anti-idiotype antibodies as vaccines to stimulate antitumor immunity is a very promising pathway in the therapy of cancer. A good body of work in animal tumor models have demonstrated the efficacy of anti-Id vaccines in preventing tumor growth and curing mice with established tumors. A number of monoclonal anti-Id antibodies that mimic different human tumor-associated antigens (TAAs) have been developed and tested in the clinic, demonstrating interesting. In general terms, the antigen mimicry by anti-Id antibodies has reflected structural homology in the most of the cases, and amino acid sequence homology in a minority of them. The major challenge of immunotherapy using anti-idiotype vaccines is to identify the optimal anti-idiotype antibody that will function as a true surrogate antigen for a TAA system, and ideally will generate both humoral and cellular immune responses. Several clinical studies have shown enhanced patient's survival when receiving anti-Id vaccines, the true demonstration of efficacy of these vaccines will depend upon the results of several randomized Phase III clinical trials that are currently planned or ongoing (Bhattacharya-Chatterjee et al.,).

  19. 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

    -five different S. aureus proteins were identified, recombinantly expressed, and tested for protection in a lethal sepsis mouse model using S. aureus strain MRSA252 as the challenge organism. We found that 13 of the 35 recombinant peptides yielded significant protection and that 12 of these antigens were highly...

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

    CSIR Research Space (South Africa)

    Meyers, A

    2008-06-23

    Full Text Available Open AcceResearch article Expression of HIV-1 antigens in plants as potential subunit vaccines Ann Meyers1,2, Ereck Chakauya1,2,3, Enid Shephard1,4, Fiona L Tanzer1,2, James Maclean1,2, Alisson Lynch1,2, Anna-Lise Williamson1,5 and Edward P Rybicki...Figure 1 The HIV-1 Gag-derived proteins used in this study. Scale diagram showing (A) native Pr55Gag ORF organisation in the Page 2 of 15 (page number not for citation purposes) gag gene, (B) the p17/p24 fusion protein ORF, (C) p24 ORF. ORFs labelled p7...

  1. Recombinant lactic acid bacteria as delivery vectors of heterologous antigens: the future of vaccination?

    Science.gov (United States)

    Trombert, A

    2015-01-01

    Lactic acid bacteria (LABs) are good candidates for the development of new oral vaccines and are attractive alternatives to attenuated pathogens. This review focuses on the use of wild-type and recombinant lactococci and lactobacilli with emphasis on their molecular design, immunomodulation and treatment of bacterial infections. The majority of studies related to recombinant LABs have focused on Lactococcus lactis, however, molecular tools have been successfully used for Lactobacillus spp. Recombinant lactobacilli and lactococci have several health benefits, such as immunomodulation, restoration of the microbiota, synthesis of antimicrobial substances and inhibition of virulence factors. In addition, protective immune responses that are well tolerated are induced by the expression of heterologous antigens from recombinant probiotics.

  2. Tracking by flow cytometry antigen-specific follicular helper T cells in wild-type animals after protein vaccination.

    Science.gov (United States)

    Chakarov, Svetoslav; Fazilleau, Nicolas

    2015-01-01

    Flow cytometry is a valuable technology used in immunology to characterize and enumerate the different cell subpopulations specific for a nonself-antigen in the context of an ongoing immune response. Among them, follicular helper T cells are the cognate regulators of B cells in secondary lymphoid tissues. Thus, tracking them is of high interest especially in the context of protein vaccination. For this purpose, transgenic antigen-receptor mouse models have been largely used. It is now clear that transgenic models are not always the best means to study the dynamics of the immune response since they can modify the response. In this chapter, we describe how to track endogenous antigen-specific follicular helper T cells by flow cytometry after protein vaccination in nonmodified wild-type animals, which ultimately provides a comprehensive way to enumerate, characterize, and isolate these particular cells in vivo.

  3. Chloroplast-derived vaccine antigens confer dual immunity against cholera and malaria by oral or injectable delivery.

    Science.gov (United States)

    Davoodi-Semiromi, Abdoreza; Schreiber, Melissa; Nalapalli, Samson; Verma, Dheeraj; Singh, Nameirakpam D; Banks, Robert K; Chakrabarti, Debopam; Daniell, Henry

    2010-02-01

    Cholera and malaria are major diseases causing high mortality. The only licensed cholera vaccine is expensive; immunity is lost in children within 3 years and adults are not fully protected. No vaccine is yet available for malaria. Therefore, in this study, the cholera toxin-B subunit (CTB) of Vibrio cholerae fused to malarial vaccine antigens apical membrane antigen-1 (AMA1) and merozoite surface protein-1 (MSP1) was expressed in lettuce and tobacco chloroplasts. Southern blot analysis confirmed homoplasmy and stable integration of transgenes. CTB-AMA1 and CTB-MSP1 fusion proteins accumulated up to 13.17% and 10.11% (total soluble protein, TSP) in tobacco and up to 7.3% and 6.1% (TSP) in lettuce, respectively. Nine groups of mice (n = 10/group) were immunized subcutaneously (SQV) or orally (ORV) with purified antigens or transplastomic tobacco leaves. Significant levels of antigen-specific antibody titres of immunized mice completely inhibited proliferation of the malarial parasite and cross-reacted with the native parasite proteins in immunoblots and immunofluorescence studies. Protection against cholera toxin challenge in both ORV (100%) and SQV (89%) mice correlated with CTB-specific titres of intestinal, serum IgA and IgG1 in ORV and only IgG1 in SQV mice, but no other immunoglobulin. Increasing numbers of interleukin-10(+) T cell but not Foxp3(+) regulatory T cells, suppression of interferon-gamma and absence of interleukin-17 were observed in protected mice, suggesting that immunity is conferred via the Tr1/Th2 immune response. Dual immunity against two major infectious diseases provided by chloroplast-derived vaccine antigens for long-term (>300 days, 50% of mouse life span) offers a realistic platform for low cost vaccines and insight into mucosal and systemic immunity.

  4. Phase II Study of HER-2/neu Intracellular Domain Peptide-Based Vaccine Administered to Stage IV HER2 Positive Breast Cancer Patients Receiving Trastuzumab

    National Research Council Canada - National Science Library

    Disis, Mary L

    2007-01-01

    The primary purpose of this grant is to determine the overall survival benefit in Stage IV HER2 positive breast cancer patients vaccinated with a HER2 ICD peptide-based vaccine while receiving maintenance trastuzumab...

  5. Phase II Study of HER-2/neu Intracellular Domain Peptide-Based Vaccine Administered to Stage IV HER2 Positive Breast Cancer Patients Receiving Trastuzumab

    National Research Council Canada - National Science Library

    Disis, Mary L

    2006-01-01

    The primary purpose of this grant is to determine the overall survival benefit in Stage IV HER2 positive breast cancer patients vaccinated with a HER2 ICD peptide-based vaccine while receiving maintenance trastuzumab...

  6. Epitope-based peptide vaccine design and target site depiction against Ebola viruses: an immunoinformatics study.

    Science.gov (United States)

    Khan, M A; Hossain, M U; Rakib-Uz-Zaman, S M; Morshed, M N

    2015-07-01

    Ebola viruses (EBOVs) have been identified as an emerging threat in recent year as it causes severe haemorrhagic fever in human. Epitope-based vaccine design for EBOVs remains a top priority because a mere progress has been made in this regard. Another reason is the lack of antiviral drug and licensed vaccine although there is a severe outbreak in Central Africa. In this study, we aimed to design an epitope-based vaccine that can trigger a significant immune response as well as to prognosticate inhibitor that can bind with potential drug target sites using various immunoinformatics and docking simulation tools. The capacity to induce both humoral and cell-mediated immunity by T cell and B cell was checked for the selected protein. The peptide region spanning 9 amino acids from 42 to 50 and the sequence TLASIGTAF were found as the most potential B and T cell epitopes, respectively. This peptide could interact with 12 HLAs and showed high population coverage up to 80.99%. Using molecular docking, the epitope was further appraised for binding against HLA molecules to verify the binding cleft interaction. In addition with this, the allergenicity of the epitopes was also evaluated. In the post-therapeutic strategy, docking study of predicted 3D structure identified suitable therapeutic inhibitor against targeted protein. However, this computational epitope-based peptide vaccine designing and target site prediction against EBOVs open up a new horizon which may be the prospective way in Ebola viruses research; the results require validation by in vitro and in vivo experiments. © 2015 John Wiley & Sons Ltd.

  7. Heat shock protein HSP60 and the perspective for future using as vaccine antigens

    Directory of Open Access Journals (Sweden)

    Joanna Bajzert

    2015-10-01

    Full Text Available Heat Shock Proteins (HSPs are widely spread in nature, highly conserved proteins, found in all prokaryotic and eukaryotic cells. HSPs have been classified in 10 families, one of them is the HSP60 family. HSP60 function in the cytoplasm as ATP-dependent molecular chaperones by assisting the folding of newly synthesised polypeptides and the assembly of multiprotein complexes. There is a large amount of evidence which demonstrate that HSP60 is expressed on the cell surface. Especially in bacteria the expression on the surface occurs constitutively and increases remarkably during host infection. HSP60 also play an important role in biofilm formation. In the extracellular environment, HSP60 alone or with self or microbial proteins can acts not only as a link between immune cells, but also as a coordinator of the immune system activity. This protein could influence the immune system in a different way because they act as an antigen, a carrier of other functional molecules or as a ligand for receptor. They are able to stimulate both cells of the acquired (naïve, effector, regulatory T lymphocyte, B lymphocyte and the innate (macrophages, monocytes, dendritic cells immune system. HSPs have been reported to be potent activators of the immune system and they are one of the immunodominant bacterial antigens they could be a good candidate for a subunit vaccine or as an adjuvant.

  8. Effect of recombinant glutathione S-transferase as vaccine antigen against Rhipicephalus appendiculatus and Rhipicephalus sanguineus infestation.

    Science.gov (United States)

    Sabadin, Gabriela Alves; Parizi, Luís Fernando; Kiio, Irene; Xavier, Marina Amaral; da Silva Matos, Renata; Camargo-Mathias, Maria Izabel; Githaka, Naftaly Wang'ombe; Nene, Vish; da Silva Vaz, Itabajara

    2017-12-04

    The ticks Rhipicephalus appendiculatus and Rhipicephalus sanguineus are the main vectors of Theileria parva and Babesia spp. in cattle and dogs, respectively. Due to their impact in veterinary care and industry, improved methods against R. appendiculatus and R. sanguineus parasitism are under development, including vaccines. We have previously demonstrated the induction of a cross-protective humoral response against Rhipicephalus microplus following vaccination with recombinant glutathione S-transferase from Haemaphysalis longicornis tick (rGST-Hl), suggesting that this protein could control tick infestations. In the present work, we investigated the effect of rGST-Hl vaccine against R. appendiculatus and R. sanguineus infestation in rabbits. In silico analysis revealed that GST from H. longicornis, R. appendiculatus and R. sanguineus have >80% protein sequence similarity, and multiple conserved antigenic sites. After the second vaccine dose, rGST-Hl-immunized rabbits showed elevated antibody levels which persisted until the end of experiment (75 and 60 days for R. appendiculatus and R. sanguineus, respectively). Western blot assays demonstrated cross-reactivity between anti-rGST-Hl antibodies and native R. appendiculatus and R. sanguineus GST extracts from ticks at different life stages. Vaccination with rGST-Hl decreased the number, weight, and fertility of engorged R. appendiculatus adults, leading to an overall vaccine efficacy of 67%. Interestingly, histological analysis of organ morphology showed damage to salivary glands and ovaries of R. appendiculatus adult females fed on vaccinated animals. In contrast, rGST-Hl vaccination did not affect R. appendiculatus nymphs, and it was ineffective against R. sanguineus across the stages of nymph and adult. Taken together, our results show the potential application of rGST-Hl as an antigen in anti-tick vaccine development, however indicating a broad difference in efficacy among tick species. Copyright © 2017 Elsevier

  9. A trivalent subunit antigen glycoprotein vaccine as immunotherapy for genital herpes in the guinea pig genital infection model.

    Science.gov (United States)

    Awasthi, Sita; Hook, Lauren M; Shaw, Carolyn E; Friedman, Harvey M

    2017-12-02

    An estimated 417 million people worldwide ages 15 to 49 are infected with herpes simplex virus type 2 (HSV-2), the most common cause of genital ulcer disease. Some individuals experience frequent recurrences of genital lesions, while others only have subclinical infection, yet all risk transmitting infection to their intimate partners. A vaccine was developed that prevents shingles, which is a recurrent infection caused by varicella-zoster virus (VZV), a closely related member of the Herpesviridae family. The success of the VZV vaccine has stimulated renewed interest in a therapeutic vaccine for genital herpes. We have been evaluating a trivalent subunit antigen vaccine for prevention of genital herpes. Here, we assess the trivalent vaccine as immunotherapy in guinea pigs that were previously infected intravaginally with HSV-2. The trivalent vaccine contains HSV-2 glycoproteins C, D, and E (gC2, gD2, gE2) subunit antigens administered with CpG and alum as adjuvants. We previously demonstrated that antibodies to gD2 neutralize the virus while antibodies to gC2 and gE2 block their immune evasion activities, including evading complement attack and inhibiting activities mediated by the IgG Fc domain, respectively. Here, we demonstrate that the trivalent vaccine significantly boosts ELISA titers and neutralizing antibody titers. The trivalent vaccine reduces the frequency of recurrent genital lesions and vaginal shedding of HSV-2 DNA by approximately 50% and almost totally eliminates vaginal shedding of replication-competent virus, suggesting that the trivalent vaccine is a worthy candidate for immunotherapy of genital herpes.

  10. A Novel Vaccine Delivery Model of the Apicomplexan Eimeria tenella Expressing Eimeria maxima Antigen Protects Chickens against Infection of the Two Parasites.

    Science.gov (United States)

    Tang, Xinming; Liu, Xianyong; Yin, Guangwen; Suo, Jingxia; Tao, Geru; Zhang, Sixin; Suo, Xun

    2017-01-01

    Vaccine delivery is critical in antigen discovery and vaccine efficacy and safety. The diversity of infectious diseases in humans and livestock has required the development of varied delivery vehicles to target different pathogens. In livestock animals, previous strategies for the development of coccidiosis vaccines have encountered several hurdles, limiting the development of multiple species vaccine formulations. Here, we describe a novel vaccine delivery system using transgenic Eimeria tenella expressing immunodominant antigens of Eimeria maxima . In this delivery system, the immune mapped protein 1 of E. maxima (EmIMP1) was delivered by the closely related species of E. tenella to the host immune system during the whole endogenous life cycle. The overexpression of the exogenous antigen did not interfere with the reproduction and immunogenicity of transgenic Eimeria . After immunization with the transgenic parasite, we detected EmIMP1's and E. maxima oocyst antigens' specific humoral and cellular immune responses. In particular, we observed partial protection of chickens immunized with transgenic E. tenella against subsequent E. maxima infections. Our results demonstrate that the transgenic Eimeria parasite is an ideal coccidia antigen delivery vehicle and represents a new type of coccidiosis vaccines. In addition, this model could potentially be used in the development of malaria live sporozoite vaccines, in which antigens from different strains can be expressed in the vaccine strain.

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

    International Nuclear Information System (INIS)

    Baranova, E.; Biketov, S.; Dunaytsev, I.; Mironova, R.; Dyatlov, I.

    2009-01-01

    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)

  12. Screening and identification of RhD antigen mimic epitopes from a phage display random peptide library for the serodiagnosis of haemolytic disease of the foetus and newborn.

    Science.gov (United States)

    Wang, Jiao; Song, Jingjing; Zhou, Shuimei; Fu, Yourong; Bailey, Jeffrey A; Shen, Changxin

    2018-01-16

    Identification of RhD antigen epitopes is a key component in understanding the pathogenesis of haemolytic disease of the foetus and newborn. Research has indicated that phage display libraries are useful tools for identifying novel mimic epitopes (mimotopes) which may help to determine antigen specificity. We selected the mimotopes of blood group RhD antigen by affinity panning a phage display library using monoclonal anti-D. After three rounds of biopanning, positive phage clones were identified by enzyme-linked immunosorbent assay (ELISA) and then sent for sequencing and peptides synthesis. Next, competitive ELISA and erythrocyte haemagglutination inhibition tests were carried out to confirm the inhibitory activity of the synthetic peptide. To evaluate the diagnostic performance of the synthetic peptide, a diagnostic ELISA was examined. Fourteen of 35 phage clones that were chosen randomly from the titering plate were considered to be positive. Following DNA sequencing and translation, 11 phage clones were found to represent the same peptide - RMKMLMMLMRRK (P4) - whereas each of the other three clones represented a unique peptide. Through the competitive ELISA and erythrocyte haemagglutination inhibition tests, the peptide (P4) was verified to have the ability to mimic the RhD antigen. The diagnostic ELISA for P4 proved to be sensitive (82.61%) and specific (88.57%). This study reveals that the P4 peptide can mimic RhD antigen and paves the way for the development of promising targeted diagnostic and therapeutic platforms for haemolytic disease of the foetus and newborn.

  13. Bacillus subtilis as a tool for vaccine development: from antigen factories to delivery vectors

    Directory of Open Access Journals (Sweden)

    Luís C.S. Ferreira

    2005-03-01

    Full Text Available Bacillus subtilis and some of its close relatives have a long history of industrial and biotechnological applications. Search for antigen expression systems based on recombinant B. subtilis strains sounds attractive both by the extensive genetic knowledge and the lack of an outer membrane, which simplify the secretion and purification of heterologous proteins. More recently, genetically modified B. subtilis spores have been described as indestructible delivery vehicles for vaccine antigens. Nonetheless both production and delivery of antigens by B. subtilis strains face some inherent obstacles, as unstable gene expression and reduced immunogenicity that, otherwise, can be overcome by already available gene technology approaches. In the present review we present the status of B. subtilis-based vaccine research, either as protein factories or delivery vectors, and discuss some alternatives for a better use of genetically modified strains.Bacillus subtilis e alguns de seus parentes mais próximos possuem uma longa história de aplicações industriais e biotecnológicas. A busca de sistemas de expressão de antígenos baseados em linhagens recombinants de B. subtilis mostra-se atrativa em função do conhecimento genético disponível e ausência de uma membrana externa, o que simplifica a secreção e a purificação de proteínas heterólogas. Mais recentemente, esporos geneticamente modificados de B. subtilis foram descritos com veículos indestrutíveis para o transporte de antígenos vacinais. Todavia a produção e o transporte de antígenos por linhagens de B. subtilis encontra obstáculos, como a expressão gênica instável e imunogenicidade reduzida, que podem ser superados com o auxílio de tecnologias genéticas atualmente disponíveis. Apresentamos nesta revisão o estado atual da pesquisa em vacinas baseadas em B. subtilis, empregado tanto como fábrica de proteínas ou veículos, e discute algumas alternativas para o uso mais

  14. Identification of candidate vaccine antigens of bovine hemoparasites Theileria parva and Babesia bovis by use of helper T cell clones.

    Science.gov (United States)

    Brown, W C; Zhao, S; Logan, K S; Grab, D J; Rice-Ficht, A C

    1995-03-01

    Current vaccines for bovine hemoparasites utilize live attenuated organisms or virulent organisms administered concurrently with antiparasitic drugs. Although such vaccines can be effective, for most hemoparasites the mechanisms of acquired resistance to challenge infection with heterologous parasite isolates have not been clearly defined. Selection of potentially protective antigens has traditionally made use of antibodies to identify immunodominant proteins. However, numerous studies have indicated that induction of high antibody titers neither predicts the ability of an antigen to confer protective immunity nor correlates with protection. Because successful parasites have evolved antibody evasion tactics, alternative strategies to identify protective immunogens should be used. Through the elaboration of cytokines, T helper 1-(Th1)-like T cells and macrophages mediate protective immunity against many intracellular parasites, and therefore most likely play an important role in protective immunity against bovine hemoparasites. CD4+ T cell clones specific for soluble or membrane antigens of either Theileria parva schizonts or Babesia bovis merozoites were therefore employed to identify parasite antigens that elicit strong Th cell responses in vitro. Soluble cytosolic parasite antigen was fractionated by gel filtration, anion exchange chromatography or hydroxylapatite chromatography, or a combination thereof, and fractions were tested for the ability to induce proliferation of Th cell clones. This procedure enabled the identification of stimulatory fractions containing T. parva proteins of approximately 10 and 24 kDa. Antisera raised against the purified 24 kDa band reacted with a native schizont protein of approximately 30 kDa. Babesia bovis-specific Th cell clones tested against fractionated soluble Babesia bovis merozoite antigen revealed the presence of at least five distinct antigenic epitopes. Proteins separated by gel filtration revealed four patterns of

  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

    2016-05-05

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Targeting of non-dominant antigens as a vaccine strategy to broaden T-cell responses during chronic viral infection

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Jensen, Benjamin Anderschou Holbech; Ragonnaud, Emeline

    2015-01-01

    In this study, we compared adenoviral vaccine vectors with the capacity to induce equally potent immune responses against non-dominant and immunodominant epitopes of murine lymphocytic choriomeningitis virus (LCMV). Our results demonstrate that vaccination targeting non-dominant epitopes facilita......In this study, we compared adenoviral vaccine vectors with the capacity to induce equally potent immune responses against non-dominant and immunodominant epitopes of murine lymphocytic choriomeningitis virus (LCMV). Our results demonstrate that vaccination targeting non-dominant epitopes...... was lost over time in T cells specific for the dominant T cell epitopes, and these cells were fully capable of expanding in response to a new viral challenge. Overall, our data suggests a potential for broadening of the antiviral CD8+ T-cell response by selecting non-dominant antigens to be targeted...

  17. 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.

  18. Recombinant Secreted Antigens from Mycoplasma hyopneumoniae Delivered as a Cocktail Vaccine Enhance the Immune Response of Mice

    Science.gov (United States)

    Galli, Vanessa; Simionatto, Simone; Marchioro, Silvana Beutinger; Klabunde, Gustavo Henrique Ferrero; Conceição, Fabricio Rochedo

    2013-01-01

    Mycoplasma hyopneumoniae is the etiological agent of porcine enzootic pneumonia (EP), which is a respiratory disease responsible for huge economic losses in the pig industry worldwide. The commercially available vaccines provide only partial protection and are expensive. Thus, the development of alternatives for the prophylaxis of EP is critical for improving pig health. The use of multiple antigens in the same immunization may represent a promising alternative. In the present study, seven secreted proteins of M. hyopneumoniae were cloned, expressed in Escherichia coli, and evaluated for antigenicity using serum from naturally and experimentally infected pigs. In addition, the immunogenicity of the seven recombinant proteins delivered individually or in protein cocktail vaccines was evaluated in mice. In Western blot assays and enzyme-linked immunosorbent assays, most of the recombinant proteins evaluated were recognized by convalescent-phase serum from the animals, indicating that they are expressed during the infectious process. The recombinant proteins were also immunogenic, and most induced a mixed IgG1/IgG2a humoral immune response. The use of these proteins in a cocktail vaccine formulation enhanced the immune response compared to their use as antigens delivered individually, providing evidence of the efficacy of the multiple-antigen administration strategy for the induction of an immune response against M. hyopneumoniae. PMID:23803903

  19. Longitudinal multiparameter single-cell analysis of macaques immunized with pneumococcal protein-conjugated or unconjugated polysaccharide vaccines reveals distinct antigen specific memory B cell repertoires.

    Directory of Open Access Journals (Sweden)

    Bin Jia

    Full Text Available The efficacy of protein-conjugated pneumococcal polysaccharide vaccines has been well characterized for children. The level of protection conferred by unconjugated polysaccharide vaccines remains less clear, particularly for elderly individuals who have had prior antigenic experience through immunization with unconjugated polysaccharide vaccines or natural exposure to Streptococcus pneumoniae.We compared the magnitude, diversity and genetic biases of antigen-specific memory B cells in two groups of adult cynomolgus macaques that were immunized with a 7-valent conjugated vaccine and boosted after five years with either a 13-valent pneumococcal polysaccharide conjugate vaccine (13vPnC or a 23-valent unconjugated pneumococcal polysaccharide vaccine (23vPS using microengraving (a single-cell analysis method and single-cell RT-PCR.Seven days after boosting, the mean frequency of antigen-specific memory B cells was significantly increased in macaques vaccinated with 13vPnC compared to those receiving 23vPS. The 13vPnC-vaccinated macaques also exhibited a more even distribution of antibody specificities to four polysaccharides in the vaccine (PS4, 6B, 14, 23F that were examined. However, single-cell analysis of the antibody variable region sequences from antigen-specific B cells elicited by unconjugated and conjugated vaccines indicated that both the germline gene segments forming the heavy chains and the average lengths of the Complementary Determining Region 3 (CDR3 were similar.Our results confirm that distinctive differences can manifest between antigen-specific memory B cell repertoires in nonhuman primates immunized with conjugated and unconjugated pneumococcal polysaccharide vaccines. The study also supports the notion that the conjugated vaccines have a favorable profile in terms of both the frequency and breadth of the anamnestic response among antigen-specific memory B cells.

  20. Computational Identification and Characterization of a Promiscuous T-Cell Epitope on the Extracellular Protein 85B of Mycobacterium spp. for Peptide-Based Subunit Vaccine Design

    Directory of Open Access Journals (Sweden)

    Md. Saddam Hossain

    2017-01-01

    Full Text Available Tuberculosis (TB is a reemerging disease that remains as a leading cause of morbidity and mortality in humans. To identify and characterize a T-cell epitope suitable for vaccine design, we have utilized the Vaxign server to assess all antigenic proteins of Mycobacterium spp. recorded to date in the Protegen database. We found that the extracellular protein 85B displayed the most robust antigenicity among the proteins identified. Computational tools for identifying T-cell epitopes predicted an epitope, 181-QQFIYAGSLSALLDP-195, that could bind to at least 13 major histocompatibility complexes, revealing the promiscuous nature of the epitope. Molecular docking simulation demonstrated that the epitope could bind to the binding groove of MHC II and MHC I molecules by several hydrogen bonds. Molecular docking analysis further revealed that the epitope had a distinctive binding pattern to all DRB1 and A and B series of MHC molecules and presented almost no polymorphism in its binding site. Moreover, using “Allele Frequency Database,” we checked the frequency of HLA alleles in the worldwide population and found a higher frequency of both class I and II HLA alleles in individuals living in TB-endemic regions. Our results indicate that the identified peptide might be a universal candidate to produce an efficient epitope-based vaccine for TB.

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

    International Nuclear Information System (INIS)

    Hebishima, Takehisa; Tada, Seiichi; Takeshima, Shin-nosuke; Akaike, Toshihiro; Ito, Yoshihiro; Aida, Yoko

    2011-01-01

    Highlights: ► To develop effective vaccine, we examined the effects of CO 3 Ap as an antigen carrier. ► OVA contained in CO 3 Ap was taken up by BMDCs more effectively than free OVA. ► OVA-immunized splenocytes was activated by OVA contained in CO 3 Ap effectively. ► OVA contained in CO 3 Ap induced strong OVA-specific immune responses to C57BL/6 mice. ► CO 3 Ap is promising antigen carrier for the achievement of effective vaccine. -- Abstract: The ability of carbonate apatite (CO 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 3 Ap more effectively than free OVA. Interestingly, mice immunized with OVA-containing CO 3 Ap produced OVA-specific antibodies more effectively than mice immunized with free OVA. Furthermore, immunization of C57BL/6 mice with OVA-containing CO 3 Ap 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 CO 3 Ap and OVA-containing alumina salt (Alum), suggesting that CO 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 3 Ap.

  2. Pretreatment antigen-specific immunity and regulation - association with subsequent immune response to anti-tumor DNA vaccination.

    Science.gov (United States)

    Johnson, Laura E; Olson, Brian M; McNeel, Douglas G

    2017-07-18

    Immunotherapies have demonstrated clinical benefit for many types of cancers, however many patients do not respond, and treatment-related adverse effects can be severe. Hence many efforts are underway to identify treatment predictive biomarkers. We have reported the results of two phase I trials using a DNA vaccine encoding prostatic acid phosphatase (PAP) in patients with biochemically recurrent prostate cancer. In both trials, persistent PAP-specific Th1 immunity developed in some patients, and this was associated with favorable changes in serum PSA kinetics. In the current study, we sought to determine if measures of antigen-specific or antigen non-specific immunity were present prior to treatment, and associated with subsequent immune response, to identify possible predictive immune biomarkers. Patients who developed persistent PAP-specific, IFNγ-secreting immune responses were defined as immune "responders." The frequency of peripheral T cell and B cell lymphocytes, natural killer cells, monocytes, dendritic cells, myeloid derived suppressor cells, and regulatory T cells were assessed by flow cytometry and clinical laboratory values. PAP-specific immune responses were evaluated by cytokine secretion in vitro, and by antigen-specific suppression of delayed-type hypersensitivity to a recall antigen in an in vivo SCID mouse model. The frequency of peripheral blood cell types did not differ between the immune responder and non-responder groups. Non-responder patients tended to have higher PAP-specific IL-10 production pre-vaccination (p = 0.09). Responder patients had greater preexisting PAP-specific bystander regulatory responses that suppressed DTH to a recall antigen (p = 0.016). While our study population was small (n = 38), these results suggest that different measures of antigen-specific tolerance or regulation might help predict immunological outcome from DNA vaccination. These will be prospectively evaluated in an ongoing randomized, phase II trial.

  3. Acanthocheilonema viteae: Vaccination of jirds with irradiation-attenuated stage-3 larvae and with exported larval antigens

    International Nuclear Information System (INIS)

    Lucius, R.; Textor, G.; Kern, A.; Kirsten, C.

    1991-01-01

    Jirds (Meriones unguiculatus) were immunized with irradiated (35 krad) stage-3 larvae (L3) of Acanthocheilonema viteae. The induced resistance against homologous challenge infection and the antibody response of the animals were studied. Immunization with 3, 2, or 1 dose of 50 irradiated L3 induced approximately 90% resistance. Immunization with a single dose of only 5 irradiated L3 resulted in 60.8% protection while immunization with a single dose of 25 L3 induced 94.1% protection. The protection induced with 3 doses of 50 irradiated L3 did not decrease significantly during a period of 6 months. Sera of a proportion, but not all resistant jirds, contained antibodies against the surface of vector derived L3 as defined by IFAT. No surface antigens of microfilariae or adult worms were recognized by the sera. Vaccinated animals had antibody responses against antigens in the inner organs of L3 and in the cuticle and reproductive organs of adult worms as shown by IFAT. Immunoblotting with SDS-PAGE-separated L3 antigens and L3-CSN revealed that all sera contained antibodies against two exported antigens of 205 and 68 kDa, and against a nonexported antigen of 18 kDa. The 205-kDa antigen easily degraded into fragments of 165, 140, 125, and 105 kDa which were recognized by resistant jird sera. Various antigens of adult worms, but relatively few antigens of microfilariae, were also recognized. To test the relevance of exported antigens of L3 to resistance, jirds were immunized with L3-CSN together with a mild adjuvant. This immunization induced 67.7% resistance against challenge infection and sera of the immunized animals recognized the 205- and 68-kDa antigens of L3

  4. Evaluation of peptide selection approaches for epitope‐based vaccine design

    DEFF Research Database (Denmark)

    Schubert, B.; Lund, Ole; Nielsen, Morten

    2013-01-01

    A major challenge in epitope-based vaccine (EV) design stems from the vast genomic variation of pathogens and the diversity of the host cellular immune system. Several computational approaches have been published to assist the selection of potential T cell epitopes for EV design. So far, no thoro......A major challenge in epitope-based vaccine (EV) design stems from the vast genomic variation of pathogens and the diversity of the host cellular immune system. Several computational approaches have been published to assist the selection of potential T cell epitopes for EV design. So far...... in terms of in silico measurements simulating important vaccine properties like the ability of inducing protection against a multivariant pathogen in a population; the predicted immunogenicity; pathogen, allele, and population coverage; as well as the conservation of selected epitopes. Additionally, we...... evaluate the use of human leukocyte antigen (HLA) supertypes with regards to their applicability for population-spanning vaccine design. The results showed that in terms of induced protection methods that simultaneously aim to optimize pathogen and HLA coverage significantly outperform methods focusing...

  5. A Novel Vaccine Delivery Model of the Apicomplexan Eimeria tenella Expressing Eimeria maxima Antigen Protects Chickens against Infection of the Two Parasites

    Science.gov (United States)

    Tang, Xinming; Liu, Xianyong; Yin, Guangwen; Suo, Jingxia; Tao, Geru; Zhang, Sixin; Suo, Xun

    2018-01-01

    Vaccine delivery is critical in antigen discovery and vaccine efficacy and safety. The diversity of infectious diseases in humans and livestock has required the development of varied delivery vehicles to target different pathogens. In livestock animals, previous strategies for the development of coccidiosis vaccines have encountered several hurdles, limiting the development of multiple species vaccine formulations. Here, we describe a novel vaccine delivery system using transgenic Eimeria tenella expressing immunodominant antigens of Eimeria maxima. In this delivery system, the immune mapped protein 1 of E. maxima (EmIMP1) was delivered by the closely related species of E. tenella to the host immune system during the whole endogenous life cycle. The overexpression of the exogenous antigen did not interfere with the reproduction and immunogenicity of transgenic Eimeria. After immunization with the transgenic parasite, we detected EmIMP1’s and E. maxima oocyst antigens’ specific humoral and cellular immune responses. In particular, we observed partial protection of chickens immunized with transgenic E. tenella against subsequent E. maxima infections. Our results demonstrate that the transgenic Eimeria parasite is an ideal coccidia antigen delivery vehicle and represents a new type of coccidiosis vaccines. In addition, this model could potentially be used in the development of malaria live sporozoite vaccines, in which antigens from different strains can be expressed in the vaccine strain. PMID:29375584

  6. Study of the peptide length and amino acid specific substitution in the antigenic activity of the chimeric synthetic peptides, containing the p19 core and gp46 envelope proteins of the HTLV-I virus.

    Science.gov (United States)

    Marin, Milenen Hernández; Rodríguez-Tanty, Chryslaine; Higginson-Clarke, David; Bocalandro, Yadaris Márquez; Peña, Lilliam Pozo

    2005-10-28

    Four chimeric synthetic peptides (Q5, Q6, Q7(multiply sign in circle), and Q8(multiply sign in circle)), incorporating immunodominant epitopes of the core p19 (105-124 a.a.) and envelope gp46 proteins (175-205 a.a.), of HTLV-I were obtained. Also, two gp46 monomeric peptides M4 and M5(multiply sign in circle) (Ser at position 192) were synthesized. The analysis of the influence of the peptide lengths and the proline to serine substitution on the chimeric and monomeric peptides' antigenicity, with regard to the chimeric peptides Q1, Q2, Q3(multiply sign in circle), and Q4(multiply sign in circle), reported previously, for HTLV-I was carried out. The peptides' antigenicity was evaluated in an ultramicroenzyme-linked immunosorbent assay (UMELISA) using sera of HTLV-I/II. The peptides' antigenicity was affected appreciably by the change of the peptide length and amino acid substitutions into the immunodominant sequence of gp46 peptide.

  7. Strong and multi-antigen specific immunity by hepatitis B core antigen (HBcAg)-based vaccines in a murine model of chronic hepatitis B: HBcAg is a candidate for a therapeutic vaccine against hepatitis B virus.

    Science.gov (United States)

    Akbar, Sheikh Mohammad Fazle; Chen, Shiyi; Al-Mahtab, Mamun; Abe, Masanori; Hiasa, Yoichi; Onji, Morikazu

    2012-10-01

    Experimental evidence suggests that hepatitis B core antigen (HBcAg)-specific cytotoxic T lymphocytes (CTL) are essential for the control of hepatitis B virus (HBV) replication and prevention of liver damage in patients with chronic hepatitis B (CHB). However, most immune therapeutic approaches in CHB patients have been accomplished with hepatitis B surface antigen (HBsAg)-based prophylactic vaccines with unsatisfactory clinical outcomes. In this study, we prepared HBsAg-pulsed dendritic cells (DC) and HBcAg-pulsed DC by culturing spleen DC from HBV transgenic mice (HBV TM) and evaluated the immunomodulatory capabilities of these antigens, which may serve as a better therapy for CHB. The kinetics of HBsAg, antibody levels against HBsAg (anti-HBs), proliferation of HBsAg- and HBcAg-specific lymphocytes, production of antigen-specific CTL, and activation of endogenous DC were compared between HBV TM vaccinated with either HBsAg- or HBcAg-pulsed DC. Vaccination with HBsAg-pulsed DC induced HBsAg-specific immunity, but failed to induce HBcAg-specific immunity in HBV TM. However, immunization of HBV TM with HBcAg-pulsed DC resulted in: (1) HBsAg negativity, (2) production of anti-HBs, and (3) development of HBsAg- and HBcAg-specific T cells and CTL in the spleen and the liver. Additionally, significantly higher levels of activated endogenous DC were detected in HBV TM immunized with HBcAg-pulsed DC compared to HBsAg-pulsed DC (pdamage suggests that HBcAg should be an integral component of the therapeutic vaccine against CHB. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Conserved Binding Regions Provide the Clue for Peptide-Based Vaccine Development: A Chemical Perspective

    Directory of Open Access Journals (Sweden)

    Hernando Curtidor

    2017-12-01

    Full Text Available Synthetic peptides have become invaluable biomedical research and medicinal chemistry tools for studying functional roles, i.e., binding or proteolytic activity, naturally-occurring regions’ immunogenicity in proteins and developing therapeutic agents and vaccines. Synthetic peptides can mimic protein sites; their structure and function can be easily modulated by specific amino acid replacement. They have major advantages, i.e., they are cheap, easily-produced and chemically stable, lack infectious and secondary adverse reactions and can induce immune responses via T- and B-cell epitopes. Our group has previously shown that using synthetic peptides and adopting a functional approach has led to identifying Plasmodium falciparum conserved regions binding to host cells. Conserved high activity binding peptides’ (cHABPs physicochemical, structural and immunological characteristics have been taken into account for properly modifying and converting them into highly immunogenic, protection-inducing peptides (mHABPs in the experimental Aotus monkey model. This article describes stereo–electron and topochemical characteristics regarding major histocompatibility complex (MHC-mHABP-T-cell receptor (TCR complex formation. Some mHABPs in this complex inducing long-lasting, protective immunity have been named immune protection-inducing protein structures (IMPIPS, forming the subunit components in chemically synthesized vaccines. This manuscript summarizes this particular field and adds our recent findings concerning intramolecular interactions (H-bonds or π-interactions enabling proper IMPIPS structure as well as the peripheral flanking residues (PFR to stabilize the MHCII-IMPIPS-TCR interaction, aimed at inducing long-lasting, protective immunological memory.

  9. Hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) combine CpG oligodeoxynucletides as a novel therapeutic vaccine for chronic hepatitis B infection.

    Science.gov (United States)

    Li, Jianqiang; Ge, Jun; Ren, Sulin; Zhou, Tong; Sun, Ying; Sun, Honglin; Gu, Yue; Huang, Hongying; Xu, Zhenxing; Chen, Xiaoxiao; Xu, Xiaowei; Zhuang, Xiaoqian; Song, Cuiling; Jia, Fangmiao; Xu, Aiguo; Yin, Xiaojin; Du, Sean X

    2015-08-20

    Hepatitis B virus infection is a non-cytopathic hepatotropic virus which can lead to chronic liver disease and hepatocellular carcinoma. Traditional therapies fail to provide sustained control of viral replication and liver damage in most patients. As an alternative strategy, immunotherapeutic approaches have shown promising efficacy in the treatment of chronic hepatitis B patients. Here, we investigated the efficacy of a novel therapeutic vaccine formulation consisting of two HBV antigens, HBsAg and HBcAg, and CpG adjuvant. This vaccine formulation elicits forceful humoral responses directed against HBsAg/HBcAg, and promotes a Th1/Th2 balance response against HBsAg and a Th1-biased response against HBcAg in both C57BL/6 and HBV transgenic mice. Vigorous cellular immune response was also detected in HBV transgenic mice, for a significantly higher number of HBs/HBc-specific IFN-γ secreting CD4+ and CD8+ T cells was generated. Moreover, vaccinated mice elicited significantly intense in vivo CTL attack, reduced serum HBsAg level without causing liver damage in HBV transgenic mice. In summary, this study demonstrates a novel therapeutic vaccine with the potential to elicit vigorous humoral and cellular response, overcoming tolerance in HBV transgenic mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Structural analysis of peptides capable of binding to more than one Ia antigen

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S

    1989-01-01

    The Ia binding regions were analyzed for three unrelated peptide Ag (sperm whale myoglobin 106-118, influenza hemagglutinin 130-142, and lambda repressor protein 12-26) for which binding to more than one Ia molecule has previously been demonstrated. By determining the binding profile of three...... separate series of truncated synthetic peptides, it was found that in all three cases the different Ia reactivities mapped to largely overlapping regions of the peptides; although, for two of the peptides, the regions involved in binding the different Ia specificities were distinct. Moreover, subtle...... differences were found to dramatically influence some, but not other, Ia reactivities. Using a large panel of synthetic peptides it was found that a significant correlation exists between the capacity of peptides to interact with different alleles of the same molecule (i.e., IAd and IAk), but no correlation...

  11. A novel peptide-nucleotide dual vaccine of human telomerase reverse transcriptase induces a potent cytotoxic T-cell response in vivo

    International Nuclear Information System (INIS)

    Guo, Hong; Hao, Jia; Wu, Chao; Shi, Yun; Zhao, Xiao-yan; Fang, Dian-chun

    2007-01-01

    Human telomerase reverse transcriptase (hTERT) is highly expressed in over 85% of human cancers, which makes it a broadly applicable molecular target for cancer therapy. Several groups have demonstrated that hTERT can efficiently evoke specific cytotoxic T lymphocytes (CTL) responses for malignant tumors. In the present study, we developed a novel virus-like particulate peptide-nucleotide dual vaccine (PNDV) of hTERT, which was composed of a low-affinity epitope variant with encoding full-length gene in the same virus-size particulate. We verified the formation of PNDV by DNA retarding assay, DNase I protection assay and transmission electron microscopy, and confirmed its immunogenicity and transfection activities in mammalian cells. Furthermore, in vivo immunization of HLA-A2.1 transgenic mice generated efficient IFN-γ secretion and hTERT-specific CTLs which are known to cause selective cell death of telomerase positive gastrointestinal cancer cells. To our knowledge, this represents the first report on collocating a low-affinity epitope variant with a full-length hTERT gene for anti-cancer vaccine design. This novel strategy for vaccine design not only enables enhanced immunity to a universal tumor antigen, but also has the potential to generate CTLs effective in telomerase-positive tumor cells of diverse tissue origins. Therefore, our findings bear significant implications for immunotherapy of human cancers

  12. I-Ad-binding peptides derived from unrelated protein antigens share a common structural motif

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S

    1988-01-01

    on the I-Ad binding of the immunogenic peptide OVA 323-339. The results obtained demonstrated the very permissive nature of Ag-Ia interaction. We also showed that unrelated peptides that are good I-Ad binders share a common structural motif and speculated that recognition of such motifs could represent...... that I-Ad molecules recognize a large library of Ag by virtue of common structural motifs present in peptides derived from phylogenetically unrelated proteins....

  13. Pregnancy Vaccination with Gold Glyco-Nanoparticles Carrying Listeria monocytogenes Peptides Protects against Listeriosis and Brain- and Cutaneous-Associated Morbidities

    Directory of Open Access Journals (Sweden)

    Ricardo Calderón-Gonzalez

    2016-08-01

    Full Text Available Listeriosis is a fatal infection for fetuses and newborns with two clinical main morbidities in the neonatal period, meningitis and diffused cutaneous lesions. In this study, we vaccinated pregnant females with two gold glyconanoparticles (GNP loaded with two peptides, listeriolysin peptide 91–99 (LLO91–99 or glyceraldehyde-3-phosphate dehydrogenase 1–22 peptide (GAPDH1–22. Neonates born to vaccinated mothers were free of bacteria and healthy, while non-vaccinated mice presented clear brain affections and cutaneous diminishment of melanocytes. Therefore, these nanoparticle vaccines are effective measures to offer pregnant mothers at high risk of listeriosis interesting therapies that cross the placenta.

  14. Pregnancy Vaccination with Gold Glyco-Nanoparticles Carrying Listeria monocytogenes Peptides Protects against Listeriosis and Brain- and Cutaneous-Associated Morbidities

    Science.gov (United States)

    Calderón-Gonzalez, Ricardo; Terán-Navarro, Héctor; Frande-Cabanes, Elisabet; Ferrández-Fernández, Eva; Freire, Javier; Penadés, Soledad; Marradi, Marco; García, Isabel; Gomez-Román, Javier; Yañez-Díaz, Sonsoles; Álvarez-Domínguez, Carmen

    2016-01-01

    Listeriosis is a fatal infection for fetuses and newborns with two clinical main morbidities in the neonatal period, meningitis and diffused cutaneous lesions. In this study, we vaccinated pregnant females with two gold glyconanoparticles (GNP) loaded with two peptides, listeriolysin peptide 91–99 (LLO91–99) or glyceraldehyde-3-phosphate dehydrogenase 1–22 peptide (GAPDH1–22). Neonates born to vaccinated mothers were free of bacteria and healthy, while non-vaccinated mice presented clear brain affections and cutaneous diminishment of melanocytes. Therefore, these nanoparticle vaccines are effective measures to offer pregnant mothers at high risk of listeriosis interesting therapies that cross the placenta. PMID:28335280

  15. A novel chimeric protein composed of recombinant Mycoplasma hyopneumoniae antigens as a vaccine candidate evaluated in mice.

    Science.gov (United States)

    de Oliveira, Natasha Rodrigues; Jorge, Sérgio; Gomes, Charles Klazer; Rizzi, Caroline; Pacce, Violetta Dias; Collares, Thais Farias; Monte, Leonardo Garcia; Dellagostin, Odir Antônio

    2017-03-01

    Enzootic Pneumonia (EP) is caused by the Mycoplasma hyopneumoniae pathogenic bacteria, and it represents a significant respiratory disease that is responsible for major economic losses within the pig industry throughout the world. The bacterins that are currently commercially available have been proven to offer only partial protection against M. hyopneumoniae, and the development of more efficient vaccines is required. Several recombinant antigens have been evaluated via different immunization strategies and have been found to be highly immunogenic. This work describes the construction and immunological characterization of a multi-antigen chimera composed of four M. hyopneumoniae antigens: P97R1, P46, P95, and P42. Immunogenic regions of each antigen were selected and combined to encode a single polypeptide. The gene was cloned and expressed in Escherichia coli, and the chimeric protein was recognized by specific antibodies against each subunit, as well as by convalescent pig sera. The immunogenic properties of the chimera were then evaluated in a mice model through two recombinant vaccines that were formulated as follows: (1) purified chimeric protein plus adjuvant or (2) recombinant Escherichia coli bacterin. The immune response induced in BALB/c mice immunized with each formulation was characterized in terms of total IgG levels, IgG1, and IgG2a isotypes against each antigen present in the chimera. The results of the study indicated that novel chimeric protein is a potential candidate for the future development of a more effective vaccine against EP. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Grafting of a peptide probe for Prostate-Specific Antigen detection using diazonium electroreduction and click chemistry.

    Science.gov (United States)

    Strzemińska, I; Sainte Rose Fanchine, S; Anquetin, G; Reisberg, S; Noël, V; Pham, M C; Piro, B

    2016-07-15

    The main objective of this work was to validate a label-free electrochemical method of protein detection using peptides as capture probes. As a proof-of-concept, we used a 7 amino acids sequence (HSSKLQL) specific for Prostate Specific Antigen. We investigated various electrografting conditions of two anilines (2-[(4-aminophenyl)sulfanyl]-8-hydroxy-1,4-naphthoquinone and 4-azidoaniline) further converted in situ into their corresponding diazonium salts on glassy carbon electrodes. It was demonstrated that the best method to obtain a mixed layer is the simultaneous electroreduction of the two diazonium salts. 4-azidoaniline was used to covalently immobilize the ethynyl-functionalized peptide probe by click coupling, and the hydroxynaphthoquinone derivative plays the role of electrochemical transducer of the peptide-protein recognition. The proteolytic activity of PSA towards a small peptide substrate carrying streptavidin at its distal end was also investigated to design an original sensing architecture leading to a reagentless, label free, and "signal-on" PSA sensor. Without optimization, the limit of quantification can be estimated in the nM to pM range. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Proteolytic activity of prostate-specific antigen (PSA towards protein substrates and effect of peptides stimulating PSA activity.

    Directory of Open Access Journals (Sweden)

    Johanna M Mattsson

    Full Text Available Prostate-specific antigen (PSA or kallikrein-related peptidase-3, KLK3 exerts chymotrypsin-like proteolytic activity. The main biological function of PSA is the liquefaction of the clot formed after ejaculation by cleavage of semenogelins I and II in seminal fluid. PSA also cleaves several other substrates, which may explain its putative functions in prostate cancer and its antiangiogenic activity. We compared the proteolytic efficiency of PSA towards several protein and peptide substrates and studied the effect of peptides stimulating the activity of PSA with these substrates. An endothelial cell tube formation model was used to analyze the effect of PSA-degraded protein fragments on angiogenesis. We showed that PSA degrades semenogelins I and II much more efficiently than other previously identified protein substrates, e.g., fibronectin, galectin-3 and IGFBP-3. We identified nidogen-1 as a new substrate for PSA. Peptides B2 and C4 that stimulate the activity of PSA towards small peptide substrates also enhanced the proteolytic activity of PSA towards protein substrates. Nidogen-1, galectin-3 or their fragments produced by PSA did not have any effect on endothelial cell tube formation. Although PSA cleaves several other protein substrates, in addition to semenogelins, the physiological importance of this activity remains speculative. The PSA levels in prostate are very high, but several other highly active proteases, such as hK2 and trypsin, are also expressed in the prostate and may cleave protein substrates that are weakly cleaved by PSA.

  18. Proteolytic Activity of Prostate-Specific Antigen (PSA) towards Protein Substrates and Effect of Peptides Stimulating PSA Activity

    Science.gov (United States)

    Mattsson, Johanna M.; Ravela, Suvi; Hekim, Can; Jonsson, Magnus; Malm, Johan; Närvänen, Ale; Stenman, Ulf-Håkan; Koistinen, Hannu

    2014-01-01

    Prostate-specific antigen (PSA or kallikrein-related peptidase-3, KLK3) exerts chymotrypsin-like proteolytic activity. The main biological function of PSA is the liquefaction of the clot formed after ejaculation by cleavage of semenogelins I and II in seminal fluid. PSA also cleaves several other substrates, which may explain its putative functions in prostate cancer and its antiangiogenic activity. We compared the proteolytic efficiency of PSA towards several protein and peptide substrates and studied the effect of peptides stimulating the activity of PSA with these substrates. An endothelial cell tube formation model was used to analyze the effect of PSA-degraded protein fragments on angiogenesis. We showed that PSA degrades semenogelins I and II much more efficiently than other previously identified protein substrates, e.g., fibronectin, galectin-3 and IGFBP-3. We identified nidogen-1 as a new substrate for PSA. Peptides B2 and C4 that stimulate the activity of PSA towards small peptide substrates also enhanced the proteolytic activity of PSA towards protein substrates. Nidogen-1, galectin-3 or their fragments produced by PSA did not have any effect on endothelial cell tube formation. Although PSA cleaves several other protein substrates, in addition to semenogelins, the physiological importance of this activity remains speculative. The PSA levels in prostate are very high, but several other highly active proteases, such as hK2 and trypsin, are also expressed in the prostate and may cleave protein substrates that are weakly cleaved by PSA. PMID:25237904

  19. The porcine circovirus type 1 capsid gene promoter improves antigen expression and immunogenicity in a HIV-1 plasmid vaccine

    Directory of Open Access Journals (Sweden)

    Burger Marieta

    2011-02-01

    Full Text Available Abstract Background One of the promising avenues for development of vaccines against Human immunodeficiency virus type 1 (HIV-1 and other human pathogens is the use of plasmid-based DNA vaccines. However, relatively large doses of plasmid must be injected for a relatively weak response. We investigated whether genome elements from Porcine circovirus type 1 (PCV-1, an apathogenic small ssDNA-containing virus, had useful expression-enhancing properties that could allow dose-sparing in a plasmid vaccine. Results The linearised PCV-1 genome inserted 5' of the CMV promoter in the well-characterised HIV-1 plasmid vaccine pTHgrttnC increased expression of the polyantigen up to 2-fold, and elicited 3-fold higher CTL responses in mice at 10-fold lower doses than unmodified pTHgrttnC. The PCV-1 capsid gene promoter (Pcap alone was equally effective. Enhancing activity was traced to a putative composite host transcription factor binding site and a "Conserved Late Element" transcription-enhancing sequence previously unidentified in circoviruses. Conclusions We identified a novel PCV-1 genome-derived enhancer sequence that significantly increased antigen expression from plasmids in in vitro assays, and improved immunogenicity in mice of the HIV-1 subtype C vaccine plasmid, pTHgrttnC. This should allow significant dose sparing of, or increased responses to, this and other plasmid-based vaccines. We also report investigations of the potential of other circovirus-derived sequences to be similarly used.

  20. Vaccine adjuvant MF59 promotes the intranodal differentiation of antigen-loaded and activated monocyte-derived dendritic cells.

    Directory of Open Access Journals (Sweden)

    Rossella Cioncada

    Full Text Available MF59 is an oil-in-water emulsion adjuvant approved for human influenza vaccination in European Union. The mode of action of MF59 is not fully elucidated yet, but results from several years of investigation indicate that MF59 establishes an immunocompetent environment at injection site which promotes recruitment of immune cells, including antigen presenting cells (APCs, that are facilitated to engulf antigen and transport it to draining lymph node (dLN where the antigen is accumulated. In vitro studies showed that MF59 promotes the differentiation of monocytes to dendritic cells (Mo-DCs. Since after immunization with MF59, monocytes are rapidly recruited both at the injection site and in dLN and appear to have a morphological change toward a DC-like phenotype, we asked whether MF59 could play a role in inducing differentiation of Mo-DC in vivo. To address this question we immunized mice with the auto-fluorescent protein Phycoerythrin (PE as model antigen, in presence or absence of MF59. We measured the APC phenotype and their antigen uptake within dLNs, the antigen distribution within the dLN compartments and the humoral response to PE. In addition, using Ovalbumin as model antigen, we measured the capacity of dLN APCs to induce antigen-specific CD4 T cell proliferation. Here, we show, for the first time, that MF59 promotes differentiation of Mo-DCs within dLNs from intranodal recruited monocytes and we suggest that this differentiation could take place in the medullary compartment of the LN. In addition we show that the Mo-DC subset represents the major source of antigen-loaded and activated APCs within the dLN when immunizing with MF59. Interestingly, this finding correlates with the enhanced triggering of antigen-specific CD4 T cell response induced by LN APCs. This study therefore demonstrates that MF59 is able to promote an immunocompetent environment also directly within the dLN, offering a novel insight on the mechanism of action of

  1. Development of stable Vibrio cholerae O1 Hikojima type vaccine strains co-expressing the Inaba and Ogawa lipopolysaccharide antigens.

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    Stefan L Karlsson

    Full Text Available We describe here the development of stable classical and El Tor V. cholerae O1 strains of the Hikojima serotype that co-express the Inaba and Ogawa antigens of O1 lipopolysaccharide (LPS. Mutation of the wbeT gene reduced LPS perosamine methylation and thereby gave only partial transformation into Ogawa LPS on the cell surface. The strains express approximately equal amounts of Inaba- and Ogawa-LPS antigens which are preserved after formalin-inactivation of the bacteria. Oral immunizations of both inbred and outbred mice with formalin-inactivated whole-cell vaccine preparations of these strains elicited strong intestinal IgA anti-LPS as well as serum vibriocidal antibody responses against both Inaba and Ogawa that were fully comparable to the responses induced by the licensed Dukoral vaccine. Passive protection studies in infant mice showed that immune sera raised against either of the novel Hikojima vaccine strains protected baby mice against infection with virulent strains of both serotypes. This study illustrates the power of using genetic manipulation to improve the properties of bacteria strains for use in killed whole-cell vaccines.

  2. 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.

  3. Characterization of the disassembly and reassembly of the HBV glycoprotein surface antigen, a pliable nanoparticle vaccine platform

    International Nuclear Information System (INIS)

    Gallagher, John R.; Torian, Udana; McCraw, Dustin M.; Harris, Audray K.

    2017-01-01

    While nanoparticle vaccine technology is gaining interest due to the success of vaccines like those for the human papillomavirus that is based on viral capsid nanoparticles, little information is available on the disassembly and reassembly of viral surface glycoprotein-based nanoparticles. One such particle is the hepatitis B virus surface antigen (sAg) that exists as nanoparticles. Here we show, using biochemical analysis coupled with electron microscopy, that sAg nanoparticle disassembly requires both reducing agent to disrupt intermolecular disulfide bonds, and detergent to disrupt hydrophobic interactions that stabilize the nanoparticle. Particles were otherwise resistant to salt and urea, suggesting the driving mechanism of particle formation involves hydrophobic interactions. We reassembled isolated sAg protein into nanoparticles by detergent removal and reassembly resulted in a wider distribution of particle diameters. Knowledge of these driving forces of nanoparticle assembly and stability should facilitate construction of epitope-displaying nanoparticles that can be used as immunogens in vaccines.

  4. Characterization of the disassembly and reassembly of the HBV glycoprotein surface antigen, a pliable nanoparticle vaccine platform

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, John R.; Torian, Udana; McCraw, Dustin M.; Harris, Audray K., E-mail: harrisau@mail.nih.gov

    2017-02-15

    While nanoparticle vaccine technology is gaining interest due to the success of vaccines like those for the human papillomavirus that is based on viral capsid nanoparticles, little information is available on the disassembly and reassembly of viral surface glycoprotein-based nanoparticles. One such particle is the hepatitis B virus surface antigen (sAg) that exists as nanoparticles. Here we show, using biochemical analysis coupled with electron microscopy, that sAg nanoparticle disassembly requires both reducing agent to disrupt intermolecular disulfide bonds, and detergent to disrupt hydrophobic interactions that stabilize the nanoparticle. Particles were otherwise resistant to salt and urea, suggesting the driving mechanism of particle formation involves hydrophobic interactions. We reassembled isolated sAg protein into nanoparticles by detergent removal and reassembly resulted in a wider distribution of particle diameters. Knowledge of these driving forces of nanoparticle assembly and stability should facilitate construction of epitope-displaying nanoparticles that can be used as immunogens in vaccines.

  5. Protection of Rhesus Monkeys by a DNA Prime/Poxvirus Boost Malaria Vaccine Depends on Optimal DNA Priming and Inclusion of Blood Stage Antigens

    Science.gov (United States)

    Weiss, Walter R.; Kumar, Anita; Jiang, George; Williams, Jackie; Bostick, Anthony; Conteh, Solomon; Fryauff, David; Aguiar, Joao; Singh, Manmohan; O'Hagan, Derek T.; Ulmer, Jeffery B.; Richie, Thomas L.

    2007-01-01

    Background We have previously described a four antigen malaria vaccine consisting of DNA plasmids boosted by recombinant poxviruses which protects a high percentage of rhesus monkeys against Plasmodium knowlesi (Pk) malaria. This is a multi-stage vaccine that includes two pre-erythrocytic antigens, PkCSP and PkSSP2(TRAP), and two erythrocytic antigens, PkAMA-1 and PkMSP-1(42kD). The present study reports three further experiments where we investigate the effects of DNA dose, timing, and formulation. We also compare vaccines utilizing only the pre-erythrocytic antigens with the four antigen vaccine. Methodology In three experiments, rhesus monkeys were immunized with malaria vaccines using DNA plasmid injections followed by boosting with poxvirus vaccine. A variety of parameters were tested, including formulation of DNA on poly-lactic co-glycolide (PLG) particles, varying the number of DNA injections and the amount of DNA, varying the interval between the last DNA injection to the poxvirus boost from 7 to 21 weeks, and using vaccines with from one to four malaria antigens. Monkeys were challenged with Pk sporozoites given iv 2 to 4 weeks after the poxvirus injection, and parasitemia was measured by daily Giemsa stained blood films. Immune responses in venous blood samples taken after each vaccine injection were measured by ELIspot production of interferon-γ, and by ELISA. Conclusions 1) the number of DNA injections, the formulation of the DNA plasmids, and the interval between the last DNA injection and the poxvirus injection are critical to vaccine efficacy. However, the total dose used for DNA priming is not as important; 2) the blood stage antigens PkAMA-1 and PkMSP-1 were able to protect against high parasitemias as part of a genetic vaccine where antigen folding is not well defined; 3) immunization with PkSSP2 DNA inhibited immune responses to PkCSP DNA even when vaccinations were given into separate legs; and 4) in a counter-intuitive result, higher

  6. Virosome-formulated Plasmodium falciparum AMA-1 & CSP derived peptides as malaria vaccine: randomized phase 1b trial in semi-immune adults & children.

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    Patrick Georges Cech

    Full Text Available This trial was conducted to evaluate the safety and immunogenicity of two virosome formulated malaria peptidomimetics derived from Plasmodium falciparum AMA-1 and CSP in malaria semi-immune adults and children.The design was a prospective randomized, double-blind, controlled, age-deescalating study with two immunizations. 10 adults and 40 children (aged 5-9 years living in a malaria endemic area were immunized with PEV3B or virosomal influenza vaccine Inflexal®V on day 0 and 90.No serious or severe adverse events (AEs related to the vaccines were observed. The only local solicited AE reported was pain at injection site, which affected more children in the Inflexal®V group compared to the PEV3B group (p = 0.014. In the PEV3B group, IgG ELISA endpoint titers specific for the AMA-1 and CSP peptide antigens were significantly higher for most time points compared to the Inflexal®V control group. Across all time points after first immunization the average ratio of endpoint titers to baseline values in PEV3B subjects ranged from 4 to 15 in adults and from 4 to 66 in children. As an exploratory outcome, we found that the incidence rate of clinical malaria episodes in children vaccinees was half the rate of the control children between study days 30 and 365 (0.0035 episodes per day at risk for PEV3B vs. 0.0069 for Inflexal®V; RR  = 0.50 [95%-CI: 0.29-0.88], p = 0.02.These findings provide a strong basis for the further development of multivalent virosomal malaria peptide vaccines.ClinicalTrials.gov NCT00513669.

  7. T Helper 17 Promotes Induction of Antigen-Specific Gut-Mucosal Cytotoxic T Lymphocytes following Adenovirus Vector Vaccination

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    Masahisa Hemmi

    2017-11-01

    Full Text Available Few current vaccines can establish antigen (Ag-specific immune responses in both mucosal and systemic compartments. Therefore, development of vaccines providing defense against diverse infectious agents in both compartments is of high priority in global health. Intramuscular vaccination of an adenovirus vector (Adv has been shown to induce Ag-specific cytotoxic T lymphocytes (CTLs in both systemic and gut-mucosal compartments. We previously found that type I interferon (IFN signaling is required for induction of gut-mucosal, but not systemic, CTLs following vaccination; however, the molecular mechanism involving type I IFN signaling remains unknown. Here, we found that T helper 17 (Th17-polarizing cytokine expression was down-regulated in the inguinal lymph nodes (iLNs of Ifnar2−/− mice, resulting in the reduction of Ag-specific Th17 cells in the iLNs and gut mucosa of the mice. We also found that prior transfer of Th17 cells reversed the decrease in the number of Ag-specific gut-mucosal CTLs in Ifnar2−/− mice following Adv vaccination. Additionally, prior transfer of Th17 cells into wild-type mice enhanced the induction of Ag-specific CTLs in the gut mucosa, but not in systemic compartments, suggesting a gut mucosa-specific mechanism where Th17 cells regulate the magnitude of vaccine-elicited Ag-specific CTL responses. These data suggest that Th17 cells translate systemic type I IFN signaling into a gut-mucosal CTL response following vaccination, which could promote the development of promising Adv vaccines capable of establishing both systemic and gut-mucosal protective immunity.

  8. Improving Multi-Epitope Long Peptide Vaccine Potency by Using a Strategy that Enhances CD4+ T Help in BALB/c Mice.

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    Haniyeh Ghaffari-Nazari

    Full Text Available Peptide-based vaccines are attractive approaches for cancer immunotherapy; but the success of these vaccines in clinical trials have been limited. Our goal is to improve immune responses and anti-tumor effects against a synthetic, multi-epitope, long peptide from rat Her2/neu (rHer2/neu using the help of CD4+ T cells and appropriate adjuvant in a mouse tumor model. Female BALB/c mice were vaccinated with P5+435 multi-epitope long peptide that presents epitopes for cytotoxic T lymphocytes (CTL in combination with a universal Pan DR epitope (PADRE or CpG-oligodeoxynucleotides (CpG-ODNs as a Toll-like receptor agonist adjuvant. The results show that vaccination with the multi-epitope long peptide in combination with the PADRE peptide and CpG-ODN induced expansion of subpopulations of CD4+ and CD8+ cells producing IFN-γ, the average tumor size in the vaccinated mice was less than that of the other groups, and tumor growth was inhibited in 40% of the mice in the vaccinated group. The mean survival time was 82.6 ± 1.25 days in mice vaccinated with P5+435 + CpG+ PADRE. Our results demonstrate that inclusion of PADRE and CpG with the peptide vaccine enhanced significant tumor specific-immune responses in vaccinated mice.

  9. Increased B and T Cell Responses in M. bovis Bacille Calmette-Guérin Vaccinated Pigs Co-Immunized with Plasmid DNA Encoding a Prototype Tuberculosis Antigen

    DEFF Research Database (Denmark)

    Bruffaerts, Nicolas; Pedersen, Lasse Eggers; Vandermeulen, Gaëlle

    2015-01-01

    derivative of tuberculin (PPD) were induced in all (BCG) vaccinated animals, but responses were much stronger in BCG-pAg85A vaccinated pigs. Finally, Ag85A-specific IFN-γ producing CD8+ T cells were detected by intracellular cytokine staining and a synthetic peptide, spanning Ag85A131-150 and encompassing...

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

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    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.

  11. Low cost tuberculosis vaccine antigens in capsules: expression in chloroplasts, bio-encapsulation, stability and functional evaluation in vitro.

    Directory of Open Access Journals (Sweden)

    Priya Saikumar Lakshmi

    Full Text Available Tuberculosis (TB caused by Mycobacterium tuberculosis is one of the leading fatal infectious diseases. The development of TB vaccines has been recognized as a major public health priority by the World Health Organization. In this study, three candidate antigens, ESAT-6 (6 kDa early secretory antigenic target and Mtb72F (a fusion polyprotein from two TB antigens, Mtb32 and Mtb39 fused with cholera toxin B-subunit (CTB and LipY (a cell wall protein were expressed in tobacco and/or lettuce chloroplasts to facilitate bioencapsulation/oral delivery. Site-specific transgene integration into the chloroplast genome was confirmed by Southern blot analysis. In transplastomic leaves, CTB fusion proteins existed in soluble monomeric or multimeric forms of expected sizes and their expression levels varied depending upon the developmental stage and time of leaf harvest, with the highest-level of accumulation in mature leaves harvested at 6PM. The CTB-ESAT6 and CTB-Mtb72F expression levels reached up to 7.5% and 1.2% of total soluble protein respectively in mature tobacco leaves. Transplastomic CTB-ESAT6 lettuce plants accumulated up to 0.75% of total leaf protein. Western blot analysis of lyophilized lettuce leaves stored at room temperature for up to six months showed that the CTB-ESAT6 fusion protein was stable and preserved proper folding, disulfide bonds and assembly into pentamers for prolonged periods. Also, antigen concentration per gram of leaf tissue was increased 22 fold after lyophilization. Hemolysis assay with purified CTB-ESAT6 protein showed partial hemolysis of red blood cells and confirmed functionality of the ESAT-6 antigen. GM1-binding assay demonstrated that the CTB-ESAT6 fusion protein formed pentamers to bind with the GM1-ganglioside receptor. The expression of functional Mycobacterium tuberculosis antigens in transplastomic plants should facilitate development of a cost-effective and orally deliverable TB booster vaccine with potential

  12. Low cost tuberculosis vaccine antigens in capsules: expression in chloroplasts, bio-encapsulation, stability and functional evaluation in vitro.

    Science.gov (United States)

    Lakshmi, Priya Saikumar; Verma, Dheeraj; Yang, Xiangdong; Lloyd, Bethany; Daniell, Henry

    2013-01-01

    Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the leading fatal infectious diseases. The development of TB vaccines has been recognized as a major public health priority by the World Health Organization. In this study, three candidate antigens, ESAT-6 (6 kDa early secretory antigenic target) and Mtb72F (a fusion polyprotein from two TB antigens, Mtb32 and Mtb39) fused with cholera toxin B-subunit (CTB) and LipY (a cell wall protein) were expressed in tobacco and/or lettuce chloroplasts to facilitate bioencapsulation/oral delivery. Site-specific transgene integration into the chloroplast genome was confirmed by Southern blot analysis. In transplastomic leaves, CTB fusion proteins existed in soluble monomeric or multimeric forms of expected sizes and their expression levels varied depending upon the developmental stage and time of leaf harvest, with the highest-level of accumulation in mature leaves harvested at 6PM. The CTB-ESAT6 and CTB-Mtb72F expression levels reached up to 7.5% and 1.2% of total soluble protein respectively in mature tobacco leaves. Transplastomic CTB-ESAT6 lettuce plants accumulated up to 0.75% of total leaf protein. Western blot analysis of lyophilized lettuce leaves stored at room temperature for up to six months showed that the CTB-ESAT6 fusion protein was stable and preserved proper folding, disulfide bonds and assembly into pentamers for prolonged periods. Also, antigen concentration per gram of leaf tissue was increased 22 fold after lyophilization. Hemolysis assay with purified CTB-ESAT6 protein showed partial hemolysis of red blood cells and confirmed functionality of the ESAT-6 antigen. GM1-binding assay demonstrated that the CTB-ESAT6 fusion protein formed pentamers to bind with the GM1-ganglioside receptor. The expression of functional Mycobacterium tuberculosis antigens in transplastomic plants should facilitate development of a cost-effective and orally deliverable TB booster vaccine with potential for long

  13. A booster vaccine expressing a latency-associated antigen augments BCG induced immunity and confers enhanced protection against tuberculosis.

    Directory of Open Access Journals (Sweden)

    Bappaditya Dey

    Full Text Available BACKGROUND: In spite of a consistent protection against tuberculosis (TB in children, Mycobacterium bovis Bacille Calmette-Guerin (BCG fails to provide adequate protection against the disease in adults as well as against reactivation of latent infections or exogenous reinfections. It has been speculated that failure to generate adequate memory T cell response, elicitation of inadequate immune response against latency-associated antigens and inability to impart long-term immunity against M. tuberculosis infections are some of the key factors responsible for the limited efficiency of BCG in controlling TB. METHODS/PRINCIPAL FINDINGS: In this study, we evaluated the ability of a DNA vaccine expressing α-crystallin--a key latency antigen of M. tuberculosis to boost the BCG induced immunity. 'BCG prime-DNA boost' regimen (B/D confers robust protection in guinea pigs along with a reduced pathology in comparison to BCG vaccination (1.37 log(10 and 1.96 log(10 fewer bacilli in lungs and spleen, respectively; p<0.01. In addition, B/D regimen also confers enhanced protection in mice. Further, we show that B/D immunization in mice results in a heightened frequency of PPD and antigen specific multi-functional CD4 T cells (3(+ simultaneously producing interferon (IFNγ, tumor necrosis factor (TNFα and interleukin (IL2. CONCLUSIONS/SIGNIFICANCE: These results clearly indicate the superiority of α-crystallin based B/D regimen over BCG. Our study, also demonstrates that protection against TB is predictable by an increased frequency of 3(+ Th1 cells with superior effector functions. We anticipate that this study would significantly contribute towards the development of superior booster vaccines for BCG vaccinated individuals. In addition, this regimen can also be expected to reduce the risk of developing active TB due to reactivation of latent infection.

  14. Mucosal vaccination with heterologous viral vectored vaccine targeting subdominant SIV accessory antigens strongly inhibits early viral replication

    DEFF Research Database (Denmark)

    Xu, Huanbin; Andersson, Anne-Marie Carola; Ragonnaud, Emeline

    2017-01-01

    Conventional HIV T cell vaccine strategies have not been successful in containing acute peak viremia, nor in providing long-term control. We immunized rhesus macaques intramuscularly and rectally using a heterologous adenovirus vectored SIV vaccine regimen encoding normally weakly immunogenic tat...

  15. Identification of pre-erythrocytic malaria antigens that target hepatocytes for killing in vivo and contribute to protection elicited by whole-parasite vaccination.

    Directory of Open Access Journals (Sweden)

    Lin Chen

    Full Text Available Pre-erythrocytic malaria vaccines, including those based on whole-parasite approaches, have shown protective efficacy in animal and human studies. However few pre-erythocytic antigens other than the immunodominant circumsporozoite protein (CSP have been studied in depth with the goal of developing potent subunit malaria vaccines that are suited for use in endemic areas. Here we describe a novel technique to identify pre-erythrocytic malaria antigens that contribute to protection elicited by whole-parasite vaccination in the mouse model. Our approach combines immunization with genetically attenuated parasites and challenge with DNA plasmids encoding for potential protective pre-erythrocytic malaria antigens as luciferase fusions by hydrodynamic tail vein injection. After optimizing the technique, we first showed that immunization with Pyfabb/f-, a P. yoelii genetically attenuated parasite, induces killing of CSP-presenting hepatocytes. Depletion of CD8+ but not CD4+ T cells diminished the killing of CSP-expressing hepatocytes, indicating that killing is CD8+ T cell-dependent. Finally we showed that the use of heterologous prime/boost immunization strategies that use genetically attenuated parasites and DNA vaccines enabled the characterization of a novel pre-erythrocytic antigen, Tmp21, as a contributor to Pyfabb/f- induced protection. This technique will be valuable for identification of potentially protective liver stage antigens and has the potential to contribute to the understanding of immunity elicited by whole parasite vaccination, as well as the development of effective subunit malaria vaccines.

  16. Human Tumor Antigens Yesterday, Today, and Tomorrow.

    Science.gov (United States)

    Finn, Olivera J

    2017-05-01

    The question of whether human tumors express antigens that can be recognized by the immune system has been answered with a resounding YES. Most were identified through spontaneous antitumor humoral and cellular immune responses found in cancer patients and include peptides, glycopeptides, phosphopeptides, viral peptides, and peptides resulting from common mutations in oncogenes and tumor-suppressor genes, or common gene fusion events. Many have been extensively tested as candidates for anticancer vaccines. More recently, attention has been focused on the potentially large number of unique tumor antigens, mutated neoantigens, that are the predicted products of the numerous mutations revealed by exome sequencing of primary tumors. Only a few have been confirmed as targets of spontaneous immunity and immunosurveillance, and even fewer have been tested in preclinical and clinical settings. The field has been divided for a long time on the relative importance of shared versus mutated antigens in tumor surveillance and as candidates for vaccines. This question will eventually need to be answered in a head to head comparison in well-designed clinical trials. One advantage that shared antigens have over mutated antigens is their potential to be used in vaccines for primary cancer prevention. Cancer Immunol Res; 5(5); 347-54. ©2017 AACR . ©2017 American Association for Cancer Research.

  17. Deinococcus Mn2+-peptide complex: A novel approach to alphavirus vaccine development.

    Science.gov (United States)

    Gayen, Manoshi; Gupta, Paridhi; Morazzani, Elaine M; Gaidamakova, Elena K; Knollmann-Ritschel, Barbara; Daly, Michael J; Glass, Pamela J; Maheshwari, Radha K

    2017-06-22

    Over the last ten years, Chikungunya virus (CHIKV), an Old World alphavirus has caused numerous outbreaks in Asian and European countries and the Americas, making it an emerging pathogen of great global health importance. Venezuelan equine encephalitis virus (VEEV), a New World alphavirus, on the other hand, has been developed as a bioweapon in the past due to its ease of preparation, aerosol dispersion and high lethality in aerosolized form. Currently, there are no FDA approved vaccines against these viruses. In this study, we used a novel approach to develop inactivated vaccines for VEEV and CHIKV by applying gamma-radiation together with a synthetic Mn-decapeptide-phosphate complex (MnDpPi), based on manganous-peptide-orthophosphate antioxidants accumulated in the extremely radiation-resistant bacterium Deinococcus radiodurans. Classical gamma-irradiated vaccine development approaches are limited by immunogenicity-loss due to oxidative damage to the surface proteins at the high doses of radiation required for complete virus-inactivation. However, addition of MnDpPi during irradiation process selectively protects proteins, but not the nucleic acids, from the radiation-induced oxidative damage, as required for safe and efficacious vaccine development. Previously, this approach was used to develop a bacterial vaccine. In the present study, we show that this approach can successfully be applied to protecting mice against viral infections. Irradiation of VEEV and CHIKV in the presence of MnDpPi resulted in substantial epitope preservation even at supra-lethal doses of gamma-rays (50,000Gy). Irradiated viruses were found to be completely inactivated and safe in vivo (neonatal mice). Upon immunization, VEEV inactivated in the presence of MnDpPi resulted in drastically improved protective efficacy. Thus, the MnDpPi-based gamma-inactivation approach described here can readily be applied to developing vaccines against any pathogen of interest in a fast and cost

  18. Cysteine mutagenesis improves the production without abrogating antigenicity of a recombinant protein vaccine candidate for human chagas disease.

    Science.gov (United States)

    Seid, Christopher A; Jones, Kathryn M; Pollet, Jeroen; Keegan, Brian; Hudspeth, Elissa; Hammond, Molly; Wei, Junfei; McAtee, C Patrick; Versteeg, Leroy; Gutierrez, Amanda; Liu, Zhuyun; Zhan, Bin; Respress, Jonathan L; Strych, Ulrich; Bottazzi, Maria Elena; Hotez, Peter J

    2017-03-04

    A therapeutic vaccine for human Chagas disease is under development by the Sabin Vaccine Institute Product Development Partnership. The aim of the vaccine is to significantly reduce the parasite burden of Trypanosoma cruzi in humans, either as a standalone product or in combination with conventional chemotherapy. Vaccination of mice with Tc24 formulated with monophosphoryl-lipid A (MPLA) adjuvant results in a Th1 skewed immune response with elevated IgG2a and IFNγ levels and a statistically significant decrease in parasitemia following T. cruzi challenge. Tc24 was therefore selected for scale-up and further evaluation. During scale up and downstream process development, significant protein aggregation was observed due to intermolecular disulfide bond formation. To prevent protein aggregation, cysteine codons were replaced with serine codons which resulted in the production of a non-aggregated and soluble recombinant protein, Tc24-C4. No changes to the secondary structure of the modified molecule were detected by circular dichroism. Immunization of mice with wild-type Tc24 or Tc24-C4, formulated with E6020 (TLR4 agonist analog to MPLA) emulsified in a squalene-oil-in-water emulsion, resulted in IgG2a and antigen specific IFNγ production levels from splenocytes that were not significantly different, indicating that eliminating putative intermolecular disulfide bonds had no significant impact on the immunogenicity of the molecule. In addition, vaccination with either formulated wild type Tc24 or Tc24-C4 antigen also significantly increased survival and reduced cardiac parasite burden in mice. Investigations are now underway to examine the efficacy of Tc24-C4 formulated with other adjuvants to reduce parasite burden and increase survival in pre-clinical studies.

  19. Vaccination Expands Antigen-Specific CD4+ Memory T Cells and Mobilizes Bystander Central Memory T Cells

    Science.gov (United States)

    Li Causi, Eleonora; Parikh, Suraj C.; Chudley, Lindsey; Layfield, David M.; Ottensmeier, Christian H.; Stevenson, Freda K.; Di Genova, Gianfranco

    2015-01-01

    CD4+ T helper memory (Thmem) cells influence both natural and vaccine-boosted immunity, but mechanisms for their maintenance remain unclear. Pro-survival signals from the common gamma-chain cytokines, in particular IL-7, appear important. Previously we showed in healthy volunteers that a booster vaccination with tetanus toxoid (TT) expanded peripheral blood TT-specific Thmem cells as expected, but was accompanied by parallel increase of Thmem cells specific for two unrelated and non cross-reactive common recall antigens. Here, in a new cohort of healthy human subjects, we compare blood vaccine-specific and bystander Thmem cells in terms of differentiation stage, function, activation and proliferative status. Both responses peaked 1 week post-vaccination. Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype. Importantly, TT-specific Thmem cells were activated (CD38High HLA-DR+), cycling or recently divided (Ki-67+), and apparently vulnerable to death (IL-7RαLow and Bcl-2 Low). In contrast, bystander Thmem cells were resting (CD38Low HLA-DR- Ki-67-) with high expression of IL-7Rα and Bcl-2. These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs. Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines. PMID:26332995

  20. Genetic and antigenic relationship of foot-and-mouth disease virus serotype O isolates with the vaccine strain O1/BFS.

    Science.gov (United States)

    Xu, Wanhong; Zhang, Zhidong; Nfon, Charles; Yang, Ming

    2018-05-15

    Foot-and-mouth disease serotype O viruses (FMDV/O) are responsible for the most outbreaks in FMD endemic countries. O1/BFS is one of the recommended FMD/O vaccine strains by World Reference Laboratory for FMD. In the current study, FMDV/O1 BFS vaccine strain and serotype O field isolates (45) were analyzed phylogenetically and antigenically to gain more insight into the genetic and antigenic characteristics of the vaccine strain and field isolates. O1/BFS showed similarity with 89% of the field isolates using a virus neutralization test (VNT). The P1 region encoding the FMDV capsid was sequenced and analysed for 46 strains of FMDV/O. Phylogenetic analysis showed these viruses originated from five continents and covered eight of 11 reported topotypes. Five isolates that demonstrated low antigenic similarities with O1/BFS were analyzed for their antigenic variation at the known neutralizing antigenic sites. Three of the five isolates demonstrated unique amino acid substitutions at various antigenic sites. No unique amino acid substitutions were observed for the other two unmatched isolates. Positively selected residues were identified on the surface of the FMD virus capsid supporting that it is important to continuously monitor field isolates for their antigenic and phenotypic changes. In conclusion, the vaccine strain O1/BFS is likely to confer protection against 89% of the 45 FMDV/O isolates based on VNT. Thus O1/BFS vaccine strain is still suitable for use in global FMD serotype O outbreak control. Combining data from phylogenetic, molecular and antigenic analysis can provide improvements in the process of vaccine selection. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  1. Therapeutic Vaccination Using Cationic Liposome-Adjuvanted HIV Type 1 Peptides Representing HLA-Supertype-Restricted Subdominant T Cell Epitopes

    DEFF Research Database (Denmark)

    Román, Victor Raúl Gómez; Jensen, Kristoffer Jarlov; Jensen, Sanne Skov

    2013-01-01

    We have designed a therapeutic HIV-1 vaccine concept based on peptides together with the adjuvant CAF01. Peptides represented 15 HLA-supertype-restricted subdominant and conserved CD8 T cell epitopes and three CD4 T-helper cell epitopes. In this phase I clinical trial, safety and immunogenicity...... were assessed in untreated HIV-1-infected individuals in Guinea-Bissau, West Africa. Twenty-three HIV-1-infected individuals were randomized to receive placebo (n=5) or vaccine (n=18). Safety was appraised by clinical follow-up combined with monitoring of biochemistry, hematology, CD4 T cell counts......, and HIV-1 viral loads. T cell immunogenicity was monitored longitudinally by interferon (IFN)-γ ELISpot. New vaccine-specific T cell responses were induced in 6/14 vaccinees for whom ELISpot data were valid. CD4 T cell counts and viral loads were stable. The study shows that therapeutic immunization...

  2. 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 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.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.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.FMP1/AS02 is not a promising candidate for further development as a monovalent malaria vaccine. Future MSP-1(42 vaccine development should focus on other formulations and antigen constructs

  3. Clinical and parasitological protection in a Leishmania infantum-macaque model vaccinated with adenovirus and the recombinant A2 antigen.

    Science.gov (United States)

    Grimaldi, Gabriel; Teva, Antonio; Porrozzi, Renato; Pinto, Marcelo A; Marchevsky, Renato S; Rocha, Maria Gabrielle L; Dutra, Miriam S; Bruña-Romero, Oscar; Fernandes, Ana-Paula; Gazzinelli, Ricardo T

    2014-06-01

    Visceral leishmaniasis (VL) is a severe vector-born disease of humans and dogs caused by Leishmania donovani complex parasites. Approximately 0.2 to 0.4 million new human VL cases occur annually worldwide. In the new world, these alarming numbers are primarily due to the impracticality of current control methods based on vector reduction and dog euthanasia. Thus, a prophylactic vaccine appears to be essential for VL control. The current efforts to develop an efficacious vaccine include the use of animal models that are as close to human VL. We have previously reported a L. infantum-macaque infection model that is reliable to determine which vaccine candidates are most worthy for further development. Among the few amastigote antigens tested so far, one of specific interest is the recombinant A2 (rA2) protein that protects against experimental L. infantum infections in mice and dogs. Primates were vaccinated using three rA2-based prime-boost immunization regimes: three doses of rA2 plus recombinant human interleukin-12 (rhIL-12) adsorbed in alum (rA2/rhIL-12/alum); two doses of non-replicative adenovirus recombinant vector encoding A2 (Ad5-A2) followed by two boosts with rA2/rhIL-12/alum (Ad5-A2+rA2/rhIL12/alum); and plasmid DNA encoding A2 gene (DNA-A2) boosted with two doses of Ad5-A2 (DNA-A2+Ad5-A2). Primates received a subsequent infectious challenge with L. infantum. Vaccines, apart from being safe, were immunogenic as animals responded with increased pre-challenge production of anti-A2-specific IgG antibodies, though with some variability in the response, depending on the vaccine formulation/protocol. The relative parasite load in the liver was significantly lower in immunized macaques as compared to controls. Protection correlated with hepatic granuloma resolution, and reduction of clinical symptoms, particularly when primates were vaccinated with the Ad5-A2+rA2/rhIL12/alum protocol. The remarkable clinical protection induced by A2 in an animal model that is

  4. Clinical and parasitological protection in a Leishmania infantum-macaque model vaccinated with adenovirus and the recombinant A2 antigen.

    Directory of Open Access Journals (Sweden)

    Gabriel Grimaldi

    2014-06-01

    Full Text Available BACKGROUND: Visceral leishmaniasis (VL is a severe vector-born disease of humans and dogs caused by Leishmania donovani complex parasites. Approximately 0.2 to 0.4 million new human VL cases occur annually worldwide. In the new world, these alarming numbers are primarily due to the impracticality of current control methods based on vector reduction and dog euthanasia. Thus, a prophylactic vaccine appears to be essential for VL control. The current efforts to develop an efficacious vaccine include the use of animal models that are as close to human VL. We have previously reported a L. infantum-macaque infection model that is reliable to determine which vaccine candidates are most worthy for further development. Among the few amastigote antigens tested so far, one of specific interest is the recombinant A2 (rA2 protein that protects against experimental L. infantum infections in mice and dogs. METHODOLOGY/PRINCIPAL FINDINGS: Primates were vaccinated using three rA2-based prime-boost immunization regimes: three doses of rA2 plus recombinant human interleukin-12 (rhIL-12 adsorbed in alum (rA2/rhIL-12/alum; two doses of non-replicative adenovirus recombinant vector encoding A2 (Ad5-A2 followed by two boosts with rA2/rhIL-12/alum (Ad5-A2+rA2/rhIL12/alum; and plasmid DNA encoding A2 gene (DNA-A2 boosted with two doses of Ad5-A2 (DNA-A2+Ad5-A2. Primates received a subsequent infectious challenge with L. infantum. Vaccines, apart from being safe, were immunogenic as animals responded with increased pre-challenge production of anti-A2-specific IgG antibodies, though with some variability in the response, depending on the vaccine formulation/protocol. The relative parasite load in the liver was significantly lower in immunized macaques as compared to controls. Protection correlated with hepatic granuloma resolution, and reduction of clinical symptoms, particularly when primates were vaccinated with the Ad5-A2+rA2/rhIL12/alum protocol. CONCLUSIONS

  5. Pathogenesis of Ovarian Serous Carcinoma as the Basis for Immunologic Directed Diagnosis and Treatment. Project 3 - Development of Antigen-Specific Cancer Vaccines for the Control of Ovarian Cancer

    National Research Council Canada - National Science Library

    Kurman, Robert

    2003-01-01

    The purpose of this study is to test whether the greater extent of intracellular spreading of encoded antigen will generate a higher degree of antigen-specific immunity and ant-tumor effects in vaccinated mice...

  6. Freeze-thaw stress of Alhydrogel ® alone is sufficient to reduce the immunogenicity of a recombinant hepatitis B vaccine containing native antigen.

    Science.gov (United States)

    Clapp, Tanya; Munks, Michael W; Trivedi, Ruchit; Kompella, Uday B; Braun, LaToya Jones

    2014-06-24

    Preventing losses in vaccine potency due to accidental freezing has recently become a topic of interest for improving vaccines. All vaccines with aluminum-containing adjuvants are susceptible to such potency losses. Recent studies have described excipients that protect the antigen from freeze-induced inactivation, prevent adjuvant agglomeration and retain potency. Although these strategies have demonstrated success, they do not provide a mechanistic understanding of freeze-thaw (FT) induced potency losses. In the current study, we investigated how adjuvant frozen in the absence of antigen affects vaccine immunogenicity and whether preventing damage to the freeze-sensitive recombinant hepatitis B surface antigen (rHBsAg) was sufficient for maintaining vaccine potency. The final vaccine formulation or Alhydrogel(®) alone was subjected to three FT-cycles. The vaccines were characterized for antigen adsorption, rHBsAg tertiary structure, particle size and charge, adjuvant elemental content and in-vivo potency. Particle agglomeration of either vaccine particles or adjuvant was observed following FT-stress. In vivo studies demonstrated no statistical differences in IgG responses between vaccines with FT-stressed adjuvant and no adjuvant. Adsorption of rHBsAg was achieved; regardless of adjuvant treatment, suggesting that the similar responses were not due to soluble antigen in the frozen adjuvant-containing formulations. All vaccines with adjuvant, including the non-frozen controls, yielded similar, blue-shifted fluorescence emission spectra. Immune response differences could not be traced to differences in the tertiary structure of the antigen in the formulations. Zeta potential measurements and elemental content analyses suggest that FT-stress resulted in a significant chemical alteration of the adjuvant surface. This data provides evidence that protecting a freeze-labile antigen from subzero exposure is insufficient to maintain vaccine potency. Future studies should

  7. Vaccination against schistosomiasis and fascioliasis with the new recombinant antigen Sm14: potential basis of a multi-valent anti-helminth vaccine?

    Directory of Open Access Journals (Sweden)

    Miriam Tendler

    1995-04-01

    Full Text Available Molecular cloning of components of protective antigenic preparations have suggested that related parasite fatty acid binding proteins could form the basis of the well documented protective, immune cross reactivity between the parasitic trematode worms Fasciola hepatica and Schistosoma mansoni. We have now confirmed the cross protective potential of parasite fatty acid binding proteins and suggest that it may be possible to produce a single vaccine that would be effective against at least two parasites, F. hepatica and S. mansoni of veterinary and human importance respectively.

  8. Comparison of serum and salivary antibodies in children vaccinated with oral live or parenteral inactivated poliovirus vaccines of different antigen concentrations.

    Science.gov (United States)

    Zaman, S; Carlsson, B; Jalil, F; Mellander, L; Van Wezel, A L; Böttiger, M; Hanson, L A

    1991-12-01

    A new antigen-rich inactivated poliovirus vaccine (IPV) in ordinary (IPV1), double (IPV2) and quadruple (IPV4) antigen concentrations was given in 2 doses to 6 and 18 week old Pakistani infants. The immune responses to poliovirus types 1 and 3 were compared to those in infants given three doses of oral poliovirus vaccine (OPV) at 6, 12 and 18 weeks of age. Enzyme-linked immunosorbent assay, ELISA, was used to estimate IgG and IgA in serum and secretory IgA (SIgA) in saliva. Two to three years later, a follow-up of the serum antibody response was carried out in the same infants using a microneutralization test. Serum IgG antibody responses to poliovirus type 1 antigen after two doses of IPV1, IPV2 and IPV4 were not significantly higher than the response after three doses of OPV at 21 weeks of age (p greater than 0.05). The serum IgG responses to poliovirus type 3 were similar to those against type 1 in all the groups. Mean neutralizing antibody titres to poliovirus type 1 was significantly higher in the IPV2 group than the rest of the groups (p less than 0.01). For type 3, these titres were highest but not significantly, in the IPV4 group (p greater than 0.05). This study shows that two doses of a new antigen-rich IPV can give similar immediate serum antibody responses as OPV but higher late responses. SIgA antibodies in saliva were more efficiently induced by OPV after three doses than after 2 doses of IPV (p less than 0.05).

  9. Affinity selection of Nipah and Hendra virus-related vaccine candidates from a complex random peptide library displayed on bacteriophage virus-like particles

    Energy Technology Data Exchange (ETDEWEB)

    Peabody, David S.; Chackerian, Bryce; Ashley, Carlee; Carnes, Eric; Negrete, Oscar

    2017-01-24

    The invention relates to virus-like particles of bacteriophage MS2 (MS2 VLPs) displaying peptide epitopes or peptide mimics of epitopes of Nipah Virus envelope glycoprotein that elicit an immune response against Nipah Virus upon vaccination of humans or animals. Affinity selection on Nipah Virus-neutralizing monoclonal antibodies using random sequence peptide libraries on MS2 VLPs selected peptides with sequence similarity to peptide sequences found within the envelope glycoprotein of Nipah itself, thus identifying the epitopes the antibodies recognize. The selected peptide sequences themselves are not necessarily identical in all respects to a sequence within Nipah Virus glycoprotein, and therefore may be referred to as epitope mimics VLPs displaying these epitope mimics can serve as vaccine. On the other hand, display of the corresponding wild-type sequence derived from Nipah Virus and corresponding to the epitope mapped by affinity selection, may also be used as a vaccine.

  10. Clinical and immunological evaluation of anti-apoptosis protein, survivin-derived peptide vaccine in phase I clinical study for patients with advanced or recurrent breast cancer

    Directory of Open Access Journals (Sweden)

    Asanuma Hiroko

    2008-05-01

    Full Text Available Abstract Background We previously reported that survivin-2B, a splicing variant of survivin, was expressed in various types of tumors and that survivin-2B peptide might serve as a potent immunogenic cancer vaccine. The objective of this study was to examine the toxicity of and to clinically and immunologically evaluate survivin-2B peptide in a phase I clinical study for patients with advanced or recurrent breast cancer. Methods We set up two protocols. In the first protocol, 10 patients were vaccinated with escalating doses (0.1–1.0 mg of survivin-2B peptide alone 4 times every 2 weeks. In the second protocol, 4 patients were vaccinated with the peptide at a dose of 1.0 mg mixed with IFA 4 times every 2 weeks. Results In the first protocol, no adverse events were observed during or after vaccination. In the second protocol, two patients had induration at the injection site. One patient had general malaise (grade 1, and another had general malaise (grade 1 and fever (grade 1. Peptide vaccination was well tolerated in all patients. In the first protocol, tumor marker levels increased in 8 patients, slightly decreased in 1 patient and were within the normal range during this clinical trial in 1 patient. With regard to tumor size, two patients were considered to have stable disease (SD. Immunologically, in 3 of the 10 patients (30%, an increase of the peptide-specific CTL frequency was detected. In the second protocol, an increase of the peptide-specific CTL frequency was detected in all 4 patients (100%, although there were no significant beneficial clinical responses. ELISPOT assay showed peptide-specific IFN-γ responses in 2 patients in whom the peptide-specific CTL frequency in tetramer staining also was increased in both protocols. Conclusion This phase I clinical study revealed that survivin-2B peptide vaccination was well tolerated. The vaccination with survivin-2B peptide mixed with IFA increased the frequency of peptide-specific CTL more

  11. A molecular basis for the presentation of phosphorylated peptides by HLA-B antigens

    NARCIS (Netherlands)

    Alpízar, Adán; Marino, Fabio; Ramos-Fernández, Antonio; Lombardía, Manuel; Jeko, Anita; Pazos, Florencio; Paradela, Alberto; Santiago, César; Heck, Albert J R; Marcilla, Miguel

    2017-01-01

    As aberrant protein phosphorylation is a hallmark of tumor cells, the display of tumor-specific phosphopeptides by Human Leukocyte Antigen (HLA) class I molecules can be exploited in the treatment of cancer by T-cell-based immunotherapy. Yet, the characterization and prediction of HLA-I

  12. Quantification of HLA-DM-Dependent Major Histocompatibility Complex of Class II Immunopeptidomes by the Peptide Landscape Antigenic Epitope Alignment Utility

    Directory of Open Access Journals (Sweden)

    Miguel Álvaro-Benito

    2018-05-01

    Full Text Available The major histocompatibility complex of class II (MHCII immunopeptidome represents the repertoire of antigenic peptides with the potential to activate CD4+ T cells. An understanding of how the relative abundance of specific antigenic epitopes affects the outcome of T cell responses is an important aspect of adaptive immunity and offers a venue to more rationally tailor T cell activation in the context of disease. Recent advances in mass spectrometric instrumentation, computational power, labeling strategies, and software analysis have enabled an increasing number of stratified studies on HLA ligandomes, in the context of both basic and translational research. A key challenge in the case of MHCII immunopeptidomes, often determined for different samples at distinct conditions, is to derive quantitative information on consensus epitopes from antigenic peptides of variable lengths. Here, we present the design and benchmarking of a new algorithm [peptide landscape antigenic epitope alignment utility (PLAtEAU] allowing the identification and label-free quantification (LFQ of shared consensus epitopes arising from series of nested peptides. The algorithm simplifies the complexity of the dataset while allowing the identification of nested peptides within relatively short segments of protein sequences. Moreover, we apply this algorithm to the comparison of the ligandomes of cell lines with two different expression levels of the peptide-exchange catalyst HLA-DM. Direct comparison of LFQ intensities determined at the peptide level is inconclusive, as most of the peptides are not significantly enriched due to poor sampling. Applying the PLAtEAU algorithm for grouping of the peptides into consensus epitopes shows that more than half of the total number of epitopes is preferentially and significantly enriched for each condition. This simplification and deconvolution of the complex and ambiguous peptide-level dataset highlights the value of the PLAt

  13. The Length of N-Glycans of Recombinant H5N1 Hemagglutinin Influences the Oligomerization and Immunogenicity of Vaccine Antigen

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    Edyta Kopera

    2017-04-01

    Full Text Available Hemagglutinin glycoprotein (HA is a principle influenza vaccine antigen. Recombinant HA-based vaccines become a potential alternative for traditional approach. Complexity and variation of HA N-glycosylation are considered as the important factors for the vaccine design. The number and location of glycan moieties in the HA molecule are also crucial. Therefore, we decided to study the effect of N-glycosylation pattern on the H5 antigen structure and its ability to induce immunological response. We also decided to change neither the number nor the position of the HA glycosylation sites but only the glycan length. Two variants of the H5 antigen with high mannose glycosylation (H5hm and with low-mannose glycosylation (H5Man5 were prepared utilizing different Pichia strains. Our structural studies demonstrated that only the highly glycosylated H5 antigen formed high molecular weight oligomers similar to viral particles. Further, the H5hm was much more immunogenic for mice than H5Man5. In summary, our results suggest that high mannose glycosylation of vaccine antigen is superior to the low glycosylation pattern. Our findings have strong implications for the recombinant HA-based influenza vaccine design.

  14. Microfluidic squeezing for intracellular antigen loading in polyclonal B-cells as cellular vaccines

    Science.gov (United States)

    Lee Szeto, Gregory; van Egeren, Debra; Worku, Hermoon; Sharei, Armon; Alejandro, Brian; Park, Clara; Frew, Kirubel; Brefo, Mavis; Mao, Shirley; Heimann, Megan; Langer, Robert; Jensen, Klavs; Irvine, Darrell J.

    2015-05-01

    B-cells are promising candidate autologous antigen-presenting cells (APCs) to prime antigen-specific T-cells both in vitro and in vivo. However to date, a significant barrier to utilizing B-cells as APCs is their low capacity for non-specific antigen uptake compared to “professional” APCs such as dendritic cells. Here we utilize a microfluidic device that employs many parallel channels to pass single cells through narrow constrictions in high throughput. This microscale “cell squeezing” process creates transient pores in the plasma membrane, enabling intracellular delivery of whole proteins from the surrounding medium into B-cells via mechano-poration. We demonstrate that both resting and activated B-cells process and present antigens delivered via mechano-poration exclusively to antigen-specific CD8+T-cells, and not CD4+T-cells. Squeezed B-cells primed and expanded large numbers of effector CD8+T-cells in vitro that produced effector cytokines critical to cytolytic function, including granzyme B and interferon-γ. Finally, antigen-loaded B-cells were also able to prime antigen-specific CD8+T-cells in vivo when adoptively transferred into mice. Altogether, these data demonstrate crucial proof-of-concept for mechano-poration as an enabling technology for B-cell antigen loading, priming of antigen-specific CD8+T-cells, and decoupling of antigen uptake from B-cell activation.

  15. Peptide and nucleotide sequences of rat CD4 (W3/25) antigen: evidence for derivation from a structure with four immunoglobulin-related domains

    International Nuclear Information System (INIS)

    Clark, S.J.; Jefferies, W.A.; Barclay, A.N.; Gagnon, J.; Williams, A.F.

    1987-01-01

    The rat W3/25 antigen was the first marker antigen of helper T lymphocytes to be identified. Subsequently, the human OKT4 antigen (now called CD4) was described, and cell distribution and functional data suggested that W3/25 and OKT4 antigens were homologous. This is now confirmed by the matching of peptide sequences from W3/25 antigen with sequence predicted from rat cDNA clones detected by cross-hybridization with a cDNA probe for human CD4. Analysis of the two sequences suggests an evolutionary origin from a structure with four immunoglobulin-related domains, although only domain 1 at the NH 2 terminus meets the standard criteria for an immunoglobulin-related sequence. CD4 domains 2 and 4 contain disulfide bonds but seem like truncated immunoglobulin domains, whereas domain 3 may have a pattern of β-strands like an immunoglobulin variable domain, but without the disulfide bond

  16. Cellular and humoral immune responses in sheep vaccinated with candidate antigens MAP2698c and MAP3567 from Mycobacterium avium subspecies paratuberculosis

    Science.gov (United States)

    Gurung, Ratna B.; Purdie, Auriol C.; Whittington, Richard J.; Begg, Douglas J.

    2014-01-01

    Control of Johne's disease, caused by Mycobacterium avium subspecies paratuberculosis (MAP) in ruminants using commercially available vaccine reduces production losses, mortality, fecal shedding and histopathological lesions but does not provide complete protection from infection and interferes with serological diagnosis of Johne's disease and bovine tuberculosis. At this time no recombinant antigens have been found to provide superior protection compared to whole killed or live-attenuated MAP vaccines. Therefore, there is a need to evaluate more candidate MAP antigens. In this study recombinant MAP antigens MAP2698c and MAP3567 were formulated with four different MONTANIDE™ (ISA 50V2, 61VG, 71VG, and 201VG) adjuvants and evaluated for their ability to produce specific immune responses in vaccinated sheep. The cellular immune response was measured with an interferon-gamma (IFN-γ) release assay and the humoral immune response was measured by antibody detection enzyme linked immunosorbent assay. Recombinant vaccine formulation with the antigen MAP2698c and MONTANIDE™ ISA 201VG adjuvant produced strong whole-MAP as well as MAP2698c-specific IFN-γ responses in a high proportion of the vaccinated sheep. The formulation caused less severe injection site lesions in comparison to other formulations. The findings from this study suggest that the MAP2698c + 201VG should be evaluated in a challenge trial to determine the efficacy of this vaccine candidate. PMID:25077074

  17. 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.

  18. The EG95 Antigen of Echinococcus spp. Contains Positively Selected Amino Acids, which May Influence Host Specificity and Vaccine Efficacy

    Science.gov (United States)

    Haag, Karen Luisa; Gottstein, Bruno; Ayala, Francisco Jose

    2009-01-01

    Echinococcosis is a worldwide zoonotic parasitic disease of humans and various herbivorous domestic animals (intermediate hosts) transmitted by the contact with wild and domestic carnivores (definitive hosts), mainly foxes and dogs. Recently, a vaccine was developed showing high levels of protection against one parasite haplotype (G1) of Echinococcus granulosus, and its potential efficacy against distinct parasite variants or species is still unclear. Interestingly, the EG95 vaccine antigen is a secreted glycosylphosphatydilinositol (GPI)-anchored protein containing a fibronectin type III domain, which is ubiquitous in modular proteins involved in cell adhesion. EG95 is highly expressed in oncospheres, the parasite life cycle stage which actively invades the intermediate hosts. After amplifying and sequencing the complete CDS of 57 Echinococcus isolates belonging to 7 distinct species, we uncovered a large amount of genetic variability, which may influence protein folding. Two positively selected sites are outside the vaccine epitopes, but are predicted to alter protein conformation. Moreover, phylogenetic analyses indicate that EG95 isoform evolution is convergent with regard to the number of beta-sheets and alpha-helices. We conclude that having a variety of EG95 isoforms is adaptive for Echinococcus parasites, in terms of their ability to invade different hosts, and we propose that a mixture of isoforms could possibly maximize vaccine efficacy. PMID:19401778

  19. 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.

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

    International Nuclear Information System (INIS)

    Meissonnier, Guylaine M.; Pinton, Philippe; Laffitte, Joelle; Cossalter, Anne-Marie; Gong, Yun Yun; Wild, Christopher P.; Bertin, Gerard; Galtier, Pierre; Oswald, Isabelle P.

    2008-01-01

    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

  1. Chemoselective ligation and antigen vectorization.

    Science.gov (United States)

    Gras-Masse, H

    2001-01-01

    The interest in cocktail-lipopeptide vaccines has now been confirmed by phase I clinical trials: highly diversified B-, T-helper or cytotoxic T-cell epitopes can be combined with a lipophilic vector for the induction of B- and T-cell responses of predetermined specificity. With the goal of producing an improved vaccine that should ideally induce a multispecific response in non-selected populations, increasing the diversity of the immunizing mixture represents one of the most obvious strategies.The selective delivery of antigens to professional antigen-presenting cells represents another promising approach for the improvement of vaccine efficacy. In this context, the mannose-receptor represents an attractive entry point for the targeting to dendritic cells of antigens linked to clustered glycosides or glycomimetics. In all cases, highly complex but fully characterized molecules must be produced. To develop a modular and flexible strategy which could be generally applicable to a large set of peptide antigens, we elected to explore the potentialities of chemoselective ligation methods. The hydrazone bond was found particularly reliable and fully compatible with sulphide ligation. Hydrazone/thioether orthogonal ligation systems could be developed to account for the nature of the antigens and the solubility of the vector systems. Copyright 2001 The International Association for Biologicals.

  2. Analysis of the DosR regulon genes to select cytotoxic T lymphocyte epitope specific vaccine candidates using a reverse vaccinology approach

    Directory of Open Access Journals (Sweden)

    Kirti Pandey

    2016-01-01

    Conclusion: Our study has generated several promiscuous antigenic peptides capable of binding to major histocompatibility complex class I with high affinity. These epitopes can become part of a postexposure multivalent subunit vaccine upon experimental validation.

  3. An Approach to Identify and Characterize a Subunit Candidate Shigella Vaccine Antigen.

    Science.gov (United States)

    Pore, Debasis; Chakrabarti, Manoj K

    2016-01-01

    Shigellosis remains a serious issue throughout the developing countries, particularly in children under the age of 5. Numerous strategies have been tested to develop vaccines targeting shigellosis; unfortunately despite several years of extensive research, no safe, effective, and inexpensive vaccine against shigellosis is available so far. Here, we illustrate in detail an approach to identify and establish immunogenic outer membrane proteins from Shigella flexneri 2a as subunit vaccine candidates.

  4. Immunogenicity of a virosomally-formulated Plasmodium falciparum GLURP-MSP3 chimeric protein-based malaria vaccine candidate in comparison to adjuvanted formulations

    DEFF Research Database (Denmark)

    Tamborrini, Marco; Stoffel, Sabine A; Westerfeld, Nicole

    2011-01-01

    In clinical trials, immunopotentiating reconstituted influenza virosomes (IRIVs) have shown great potential as a versatile antigen delivery platform for synthetic peptides derived from Plasmodium falciparum antigens. This study describes the immunogenicity of a virosomally-formulated recombinant ...... fusion protein comprising domains of the two malaria vaccine candidate antigens MSP3 and GLURP....

  5. The Non-structural Protein 5 and Matrix Protein Are Antigenic Targets of T Cell Immunity to Genotype 1 Porcine Reproductive and Respiratory Syndrome Viruses

    DEFF Research Database (Denmark)

    Mokhtar, Helen; Pedrera, Miriam; Frossard, Jean-Pierre

    2016-01-01

    The porcine reproductive and respiratory syndrome virus (PRRSV) is the cause of one of the most economically important diseases affecting swine worldwide. Efforts to develop a next-generation vaccine have largely focused on envelope glycoproteins to target virus-neutralizing antibody responses...... proposed that T cell-mediated immunity plays a key role. Therefore, we hypothesized that conserved T cell antigens represent prime candidates for the development a novel PRRS vaccine. Antigens were identified by screening a proteome-wide synthetic peptide library with T cells from cohorts of pigs rendered...... attractive vaccine candidate T cell antigens, which should be evaluated further in the context of PRRSV vaccine development....

  6. Extending the honey bee venome with the antimicrobial peptide apidaecin and a protein resembling wasp antigen 5.

    Science.gov (United States)

    Van Vaerenbergh, M; Cardoen, D; Formesyn, E M; Brunain, M; Van Driessche, G; Blank, S; Spillner, E; Verleyen, P; Wenseleers, T; Schoofs, L; Devreese, B; de Graaf, D C

    2013-04-01

    Honey bee venom is a complex mixture of toxic proteins and peptides. In the present study we tried to extend our knowledge of the venom composition using two different approaches. First, worker venom was analysed by liquid chromatography-mass spectrometry and this revealed the antimicrobial peptide apidaecin for the first time in such samples. Its expression in the venom gland was confirmed by reverse transcription PCR and by a peptidomic analysis of the venom apparatus tissue. Second, genome mining revealed a list of proteins with resemblance to known insect allergens or venom toxins, one of which showed homology to proteins of the antigen 5 (Ag5)/Sol i 3 cluster. It was demonstrated that the honey bee Ag5-like gene is expressed by venom gland tissue of winter bees but not of summer bees. Besides this seasonal variation, it shows an interesting spatial expression pattern with additional production in the hypopharyngeal glands, the brains and the midgut. Finally, our immunoblot study revealed that both synthetic apidaecin and the Ag5-like recombinant from bacteria evoke no humoral activity in beekeepers. Also, no IgG4-based cross-reactivity was detected between the honey bee Ag5-like protein and its yellow jacket paralogue Ves v 5. © 2013 Royal Entomological Society.

  7. Antigenic specificity of a monovalent versus polyvalent MOMP based Chlamydia pecorum vaccine in koalas (Phascolarctos cinereus).

    Science.gov (United States)

    Kollipara, Avinash; Wan, Charles; Rawlinson, Galit; Brumm, Jacqui; Nilsson, Karen; Polkinghorne, Adam; Beagley, Kenneth; Timms, Peter

    2013-02-06

    Chlamydia continues to be a major pathogen of koalas. The bacterium is associated with ocular, respiratory and urogenital tract infections and a vaccine is considered the best option to limit the decline of mainland koala populations. Over the last 20 years, efforts to develop a chlamydial vaccine in humans have focussed on the use of the chlamydial major outer membrane protein (MOMP). Potential problems with the use of MOMP-based vaccines relate to the wide range of genetic diversity in its four variable domains. In the present study, we evaluated the immune response of koalas vaccinated with a MOMP-based C. pecorum vaccine formulated with genetically and serologically diverse MOMPs. Animals immunised with individual MOMPs developed strong antibody and lymphocyte proliferation responses to both homologous as well as heterologous MOMP proteins. Importantly, we also showed that vaccine induced antibodies which effectively neutralised various heterologous strains of koala C. pecorum in an in vitro assay. Finally, we also demonstrated that the immune responses in monovalent as well as polyvalent MOMP vaccine groups were able to recognise whole chlamydial elementary bodies, illustrating the feasibility of developing an effective MOMP based C. pecorum vaccine that could protect against a range of strains. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  8. Heat shock protein-peptide complex-96 (Vitespen for the treatment of cancer

    Directory of Open Access Journals (Sweden)

    Robert J. Amato

    2011-12-01

    Full Text Available Heat shock proteins (HSPs are the most abundant and ubiquitous soluble intracellular proteins. Members of the HSP family bind peptides, they include antigenic peptides generated within cells. HSPs also interact with antigen-presenting cells (APCs through CD91 and other receptors, eliciting a cascade of events that includes re-presentation of HSP-chaperoned peptides by major histocompatability complex (MHC, translocation of nuclear factorkappaB (NFkB into the nuclei, and maturation of dendritic cells (DCs. These consequences point to a key role of heat shock proteins in fundamental immunological phenomena such as activation of APCs, indirect presentation (or crosspriming of antigenic peptides, and chaperoning of peptides during antigen presentation. The properties of HSPs also allow them to be used for immunotherapy of cancers and infections in novel ways. This paper reviews the development and clinical trial progress of vitespen, an HSP peptide complex vaccine based on tumor-derived glycoprotein 96.

  9. Formulation of the bivalent prostate cancer vaccine with surgifoam elicits antigen-specific effector T cells in PSA-transgenic mice.

    Science.gov (United States)

    Karan, Dev

    2017-10-13

    We previously developed and characterized an adenoviral-based prostate cancer vaccine for simultaneous targeting of prostate-specific antigen (PSA) and prostate stem cell antigen (PSCA). We also demonstrated that immunization of mice with the bivalent vaccine (Ad 5 -PSA+PSCA) inhibited the growth of established prostate tumors. However, there are multiple challenges hindering the success of immunological therapies in the clinic. One of the prime concerns has been to overcome the immunological tolerance and maintenance of long-term effector T cells. In this study, we further characterized the use of the bivalent vaccine (Ad 5 -PSA+PSCA) in a transgenic mouse model expressing human PSA in the mouse prostate. We demonstrated the expression of PSA analyzed at the mRNA level (by RT-PCR) and protein level (by immunohistochemistry) in the prostate lobes harvested from the PSA-transgenic (PSA-Tg) mice. We established that the administration of the bivalent vaccine in surgifoam to the PSA-Tg mice induces strong PSA-specific effector CD8 + T cells as measured by IFN-γ secretion and in vitro cytotoxic T-cell assay. Furthermore, the use of surgifoam with Ad 5 -PSA+PSCA vaccine allows multiple boosting vaccinations with a significant increase in antigen-specific CD8 + T cells. These observations suggest that the formulation of the bivalent prostate cancer vaccine (Ad 5 -PSA+PSCA) with surgifoam bypasses the neutralizing antibody response, thus allowing multiple boosting. This formulation is also helpful for inducing an antigen-specific immune response in the presence of self-antigen, and maintains long-term effector CD8 + T cells. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  10. Optimization of inactivated H5N9 highly pathogenic avian influenza vaccine and inactivated Salmonella enterica serovar Typhimurium vaccine with antigen dose and prime-boost regimen in domestic ducks.

    Science.gov (United States)

    Yuk, Seong-Su; To, Eredene-Ochir; Kwon, Jung-Hoon; Noh, Jin-Yong; Hong, Woo-Tack; Jeong, Jei-Hyun; Gwon, Gyeong-Bin; Song, Chang-Seon

    2017-09-01

    Owing to the increase in the number of diseases affecting ducks and the demand for food safety by consumers, vaccination has become one of the factors that influence duck meat productivity. The highly pathogenic avian influenza (HPAI) virus is one of the most prevalent and causes one of the most lethal diseases in domestic ducks, and Salmonella enterica serovar Typhimurium is a food-borne pathogen persistent in the domestic duck population. To better understand the optimal usage of HPAI and S. enterica serovar Typhimurium vaccines, we aimed to determine antigen dose, oil and gel adjuvant usage with prime-boost regimen, and vaccination age, inducing the best immune response in ducks, without an effect on body weight gain. In the case of the inactivated H5N9 vaccine, a single dose of vaccine was inadequate to induce proper antibody titer when administered to day-old ducks, which necessitates boost vaccination. Administration of the oil-adjuvanted H5N9 vaccine administration in day-old and 2-week-old ducks resulted in a lower body weight at the time of slaughtering, compared to that of gel-adjuvanted H5N9 vaccine. However, gel-adjuvanted H5N9 vaccine failed to induce proper immune response to an extent recommend by OIE-World Organization for Animal Health. In the case of the Salmonella enterica serovar Typhimurium vaccine, a moderate or low dose of vaccine was appropriate for day-old ducks receiving the gel prime-oil boost vaccination. Single vaccination with oil adjuvants affects the mean body weight of 7-week-old ducks, suggesting that the gel adjuvant is more suitable for meat production. We expect that the use of adjuvants in a prime-boost regimen and at antigen doses set in this study will be helpful to maximize body weight in the case of domestic duck production at the actual farm site. © 2017 Poultry Science Association Inc.

  11. Fc receptor-targeting of immunogen as a strategy for enhanced antigen loading, vaccination, and protection using intranasally administered antigen-pulsed dendritic cells.

    Science.gov (United States)

    Pham, Giang H; Iglesias, Bibiana V; Gosselin, Edmund J

    2014-09-08

    Dendritic cells (DCs) play a critical role in the generation of adaptive immunity via the efficient capture, processing, and presentation of antigen (Ag) to naïve T cells. Administration of Ag-pulsed DCs is also an effective strategy for enhancing immunity to tumors and infectious disease organisms. Studies have also demonstrated that targeting Ags to Fcγ receptors (FcγR) on Ag presenting cells can enhance humoral and cellular immunity in vitro and in vivo. Specifically, our studies using a Francisella tularensis (Ft) infectious disease vaccine model have demonstrated that targeting immunogens to FcγR via intranasal (i.n.) administration of monoclonal antibody (mAb)-inactivated Ft (iFt) immune complexes (ICs) enhances protection against Ft challenge. Ft is the causative agent of tularemia, a debilitating disease of humans and other mammals and a category A biothreat agent for which there is no approved vaccine. Therefore, using iFt Ag as a model immunogen, we sought to determine if ex vivo targeting of iFt to FcγR on DCs would enhance the potency of i.n. administered iFt-pulsed DCs. In this study, bone marrow-derived DCs (BMDCs) were pulsed ex vivo with iFt or mAb-iFt ICs. Intranasal administration of mAb-iFt-pulsed BMDCs enhanced humoral and cellular immune responses, as well as protection against Ft live vaccine strain (LVS) challenge. Increased protection correlated with increased iFt loading on the BMDC surface as a consequence of FcγR-targeting. However, the inhibitory FcγRIIB had no impact on this enhancement. In conclusion, targeting Ag ex vivo to FcγR on DCs provides a method for enhanced Ag loading of DCs ex vivo, thereby reducing the amount of Ag required, while also avoiding the inhibitory impact of FcγRIIB. Thus, this represents a simple and less invasive strategy for increasing the potency of ex vivo-pulsed DC vaccines against chronic infectious diseases and cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Fc Receptor-Targeting of Immunogen as a Strategy for Enhanced Antigen Loading, Vaccination, and Protection Using Intranasally-Administered Antigen-Pulsed Dendritic Cells

    Science.gov (United States)

    Pham, Giang H.; Iglesias, Bibiana V.; Gosselin, Edmund J.

    2014-01-01

    Dendritic cells (DCs) play a critical role in the generation of adaptive immunity via the efficient capture, processing, and presentation of antigen (Ag) to naïve T cells. Administration of Ag-pulsed DCs is also an effective strategy for enhancing immunity to tumors and infectious disease organisms. Studies have also demonstrated that targeting Ags to Fcγ receptors (FcγR) on Ag presenting cells can enhance humoral and cellular immunity in vitro and in vivo. Specifically, our studies using an F. tularensis (Ft) infectious disease vaccine model have demonstrated that targeting immunogens to FcγR via intranasal (i.n.) administration of monoclonal antibody (mAb)-inactivated Ft (iFt) immune complexes (ICs) enhances protection against Ft challenge. Ft is the causative agent of tularemia, a debilitating disease of humans and other mammals and a category A biothreat agent for which there is no approved vaccine. Therefore, using iFt Ag as a model immunogen, we sought to determine if ex vivo targeting of iFt to FcγR on DCs would enhance the potency of i.n. administered iFt-pulsed DCs. In this study, bone marrow-derived DCs (BMDCs) were pulsed ex vivo with iFt or mAb-iFt ICs. Intranasal administration of mAb-iFt-pulsed BMDCs enhanced humoral and cellular immune responses, as well as protection against Ft live vaccine strain (LVS) challenge. Increased protection correlated with increased iFt loading on the BMDC surface as a consequence of FcγR targeting. However, the inhibitory FcγRIIB had no impact on this enhancement. In conclusion, targeting Ag ex vivo to FcγR on DCs provides a method for enhanced Ag loading of DCs ex vivo, thereby reducing the amount of Ag required, while also avoiding the inhibitory impact of FcγRIIB. Thus, this represents a simple and less invasive strategy for increasing the potency of ex vivo-pulsed DC vaccines against chronic infectious diseases and cancer. PMID:25068496

  13. Evolution of the Sabin vaccine into pathogenic derivatives without appreciable changes in antigenic properties: need for improvement of current poliovirus surveillance.

    Science.gov (United States)

    Yakovenko, Maria L; Korotkova, Ekaterina A; Ivanova, Olga E; Eremeeva, Tatyana P; Samoilovich, Elena; Uhova, Iryna; Gavrilin, Gene V; Agol, Vadim I

    2009-04-01

    The Sabin oral polio vaccine (OPV) may evolve into pathogenic viruses, causing sporadic cases and outbreaks of poliomyelitis. Such vaccine-derived polioviruses (VDPV) generally exhibit altered antigenicity. The current paradigm to distinguish VDPV from OPV and wild polioviruses is to characterize primarily those poliovirus isolates that demonstrate deviations from OPV in antigenic and genetic intratypic differentiation (ITD) tests. Here we report on two independent cases of poliomyelitis caused by VDPVs with "Sabin-like" properties in several ITD assays. The results suggest the existence of diverse pathways of OPV evolution and necessitate improvement of poliovirus surveillance, which currently potentially misses this class of VDPV.

  14. Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route

    OpenAIRE

    Carey, John B.; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V. S.; Draper, Simon J.; Moore, Anne C.

    2014-01-01

    Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP142, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delive...

  15. Synthetic Self-Adjuvanting Glycopeptide Cancer Vaccines

    Science.gov (United States)

    Payne, Richard; McDonald, David; Byrne, Scott

    2015-10-01

    Due to changes in glycosyltransferase expression during tumorigenesis, the glycoproteins of cancer cells often carry highly truncated carbohydrate chains compared to those on healthy cells. These glycans are known as tumor-associated carbohydrate antigens, and are prime targets for use in vaccines for the prevention and treatment of cancer. Herein, we review the state-of-the-art in targeting the immune system towards tumor-associated glycopeptide antigens via synthetic self adjuvanting vaccines, in which the antigenic and adjuvanting moieties of the vaccines are present in the same molecule. The majority of the self-adjuvanting glycopeptide cancer vaccines reported to date employ antigens from mucin 1, a protein which is highly over-expressed and aberrantly glycosylated in many forms of cancer. The adjuvants used in these vaccines predominantly include lipopeptide- or lipoamino acid-based TLR2 agonists, although studies investigating stimulation of TLR9 and TLR4 are also discussed. Most of these adjuvants are highly lipophilic, and, upon conjugation to antigenic peptides, provide amphiphilic vaccine molecules. The amphiphilic nature of these vaccine constructs can lead to the formation of higher-order structures by vaccines in solution, which are likely to be important for their efficacy in vivo.

  16. 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

  17. 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. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  18. Exosomes as potent cell-free peptide-based vaccine. II. Exosomes in CpG adjuvants efficiently prime naive Tc1 lymphocytes leading to tumor rejection.

    NARCIS (Netherlands)

    Chaput, N.; Schartz, N.E.; Andre, F.; Taieb, J.; Novault, S.; Bonnaventure, P.; Aubert, N.; Bernard, J.; Lemonnier, F.; Merad, M.; Adema, G.J.; Adams, M.; Ferrantini, M.; Carpentier, A.F.; Escudier, B.; Tursz, T.; Angevin, E.; Zitvogel, L.

    2004-01-01

    Ideal vaccines should be stable, safe, molecularly defined, and out-of-shelf reagents efficient at triggering effector and memory Ag-specific T cell-based immune responses. Dendritic cell-derived exosomes could be considered as novel peptide-based vaccines because exosomes harbor a discrete set of

  19. Dendritic cells induce specific cytotoxic T lymphocytes against prostate cancer TRAMP-C2 cells loaded with freeze- thaw antigen and PEP-3 peptide.

    Science.gov (United States)

    Liu, Xiao-Qi; Jiang, Rong; Li, Si-Qi; Wang, Jing; Yi, Fa-Ping

    2015-01-01

    Prostate cancer is the most common cancer in men. In this study, we investigated immune responses of cytotoxic T lymphocytes (CTLs) against TRAMP-C2 prostate cancer cells after activation by dendritic cells (DCs) loaded with TRAMP-C2 freeze-thaw antigen and/or PEP-3 peptide in vitro. Bone marrow-derived DC from the bone marrow of the C57BL/6 were induced to mature by using the cytokine of rhGM-CSF and rhIL-4, and loaded with either the freeze-thaw antigen or PEP-3 peptide or both of them. Maturation of DCs was detected by flow cytometry. The killing efficiency of the CTLs on TRAMP-C2 cells were detected by flow cytometry, CCK8, colony formation, transwell migration, and wound-healing assay. The levels of the IFN-γ, TNF-β and IL-12 were measured by enzyme-linked immunosorbent assay (ELISA). Compared with the unloaded DCs, the loaded DCs had significantly increased expression of several phenotypes related to DC maturation. CTLs activated by DCs loaded with freeze-thaw antigen and PEP-3 peptide had more evident cytotoxicity against TRAMP-C2 cells in vitro. The secretion levels of IFN-γ, TNF-β and IL-12, secreted by DCs loaded with antigen and PEP-3 and interaction with T cells, were higher than in the other groups. Our results suggest that the CTLs activated by DCs loaded with TRAMP-C2 freeze-thaw antigen and PEP-3 peptide exert a remarkable killing efficiency against TRAMP-C2 cells in vitro.

  20. Antigen-specific immature dendritic cell vaccine ameliorates anti-dsDNA antibody-induced renal damage in a mouse model.

    Science.gov (United States)

    Xia, Yumin; Jiang, Shan; Weng, Shenhong; Lv, Xiaochun; Cheng, Hong; Fang, Chunhong

    2011-12-01

    Dendritic cells (DCs) can inhibit immune response by clonal anergy when immature. Recent studies have shown that immature DCs (iDCs) may serve as a live cell vaccine after specific antigen pulse based on its potential of blocking antibody production. In this study, we aimed to investigate the effects of nuclear antigen-pulsed iDCs in the treatment of lupus-like renal damages induced by anti-dsDNA antibodies. iDCs were generated from haemopoietic stem cells in bone marrow and then pulsed in vitro with nuclear antigen. The iDC vaccine and corresponding controls were injected into mice with lupus-like renal damages. The evaluation of disease was monitored by biochemical parameters and histological scores. Anti-dsDNA antibody isotypes and T-lymphocyte-produced cytokines were analysed for elucidating therapeutic mechanisms. RESULTS; The mice treated with antigen-pulsed iDCs had a sustained remission of renal damage compared with those injected with non-pulsed iDCs or other controls, including decreased anti-dsDNA antibody level, less proteinuria, lower blood urea nitrogen and serum creatinine values, and improved histological evaluation. Analysis on isotypes of anti-dsDNA antibody showed that iDC vaccine preferentially inhibited the production of IgG3, IgG2b and IgG2a. Furthermore, administration of antigen-treated iDCs to mice resulted in significantly reduced IL-2, IL-4 and IL-12 and IFN-γ produced by T-memory cells. Conversely, the vaccination of antigen-pulsed mature DCs led to increased anti-dsDNA antibody production and an aggravation of lupus-like disease in the model. CONCLUSIONS; These results suggested the high potency of iDC vaccine in preventing lupus-like renal injuries induced by pathogenic autoantibodies.

  1. 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

    2010-03-01

    Full Text Available 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.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.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.

  2. Green revolution vaccines, edible vaccines

    African Journals Online (AJOL)

    Admin

    of development. Food vaccines may also help to suppress autoimmunity disorders such as Type-1. Diabetes. Key words: Edible vaccines, oral vaccines, antigen expression, food vaccines. INTRODUCTION. Vaccination involves the stimulation of the immune system to prepare it for the event of an invasion from a particular ...

  3. 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.

  4. Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route.

    Science.gov (United States)

    Carey, John B; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V S; Draper, Simon J; Moore, Anne C

    2014-08-21

    Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP1₄₂, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delivery. Microneedle-mediated vaccine priming and resultant induction of low anti-vector antibody titres permitted repeated use of the same adenovirus vaccine vector. This resulted in significantly increased antigen-specific antibody responses in these mice compared to ID-treated mice. Boosting with a heterologous vaccine; MVA-PyMSP1₄₂ also resulted in significantly greater antibody responses in mice primed with HAdV5-PyMSP1₄₂ using MN compared to the ID route. The highest protection against blood-stage malaria challenge was observed when a heterologous route of immunization (MN/ID) was used. Therefore, microneedle-mediated immunization has potential to both overcome some of the logistic obstacles surrounding needle-and-syringe-based immunization as well as to facilitate the repeated use of the same adenovirus vaccine thereby potentially reducing manufacturing costs of multiple vaccines. This could have important benefits in the clinical ease of use of adenovirus-based immunization strategies.

  5. Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route

    Science.gov (United States)

    Carey, John B.; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V. S.; Draper, Simon J.; Moore, Anne C.

    2014-01-01

    Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP142, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delivery. Microneedle-mediated vaccine priming and resultant induction of low anti-vector antibody titres permitted repeated use of the same adenovirus vaccine vector. This resulted in significantly increased antigen-specific antibody responses in these mice compared to ID-treated mice. Boosting with a heterologous vaccine; MVA-PyMSP142 also resulted in significantly greater antibody responses in mice primed with HAdV5-PyMSP142 using MN compared to the ID route. The highest protection against blood-stage malaria challenge was observed when a heterologous route of immunization (MN/ID) was used. Therefore, microneedle-mediated immunization has potential to both overcome some of the logistic obstacles surrounding needle-and-syringe-based immunization as well as to facilitate the repeated use of the same adenovirus vaccine thereby potentially reducing manufacturing costs of multiple vaccines. This could have important benefits in the clinical ease of use of adenovirus-based immunization strategies. PMID:25142082

  6. Proteomics-Based Characterization of the Humoral Immune Response in Sporotrichosis: Toward Discovery of Potential Diagnostic and Vaccine Antigens.

    Directory of Open Access Journals (Sweden)

    Anderson Messias Rodrigues

    Full Text Available Sporothrix schenckii and associated species are agents of human and animal sporotrichosis that cause large sapronoses and zoonoses worldwide. Epidemiological surveillance has highlighted an overwhelming occurrence of the highly pathogenic fungus Sporothrix brasiliensis during feline outbreaks, leading to massive transmissions to humans. Early diagnosis of feline sporotrichosis by demonstrating the presence of a surrogate marker of infection can have a key role for selecting appropriate disease control measures and minimizing zoonotic transmission to humans.We explored the presence and diversity of serum antibodies (IgG specific against Sporothrix antigens in cats with sporotrichosis and evaluated the utility of these antibodies for serodiagnosis. Antigen profiling included protein extracts from the closest known relatives S. brasiliensis and S. schenckii. Enzyme-linked immunosorbent assays and immunoblotting enabled us to characterize the major antigens of feline sporotrichosis from sera from cats with sporotrichosis (n = 49, healthy cats (n = 19, and cats with other diseases (n = 20.Enzyme-linked immunosorbent assay-based quantitation of anti-Sporothrix IgG exhibited high sensitivity and specificity in cats with sporotrichosis (area under the curve, 1.0; 95% confidence interval, 0.94-1; P<0.0001 versus controls. The two sets of Sporothrix antigens were remarkably cross-reactive, supporting the hypothesis that antigenic epitopes may be conserved among closely related agents. One-dimensional immunoblotting indicated that 3-carboxymuconate cyclase (a 60-kDa protein in S. brasiliensis and a 70-kDa protein in S. schenckii is the immunodominant antigen in feline sporotrichosis. Two-dimensional immunoblotting revealed six IgG-reactive isoforms of gp60 in the S. brasiliensis proteome, similar to the humoral response found in human sporotrichosis.A convergent IgG-response in various hosts (mice, cats, and humans has important implications for our

  7. Augmentation of antigen-specific immune responses using DNA-fusogenic liposome vaccine

    International Nuclear Information System (INIS)

    Yoshikawa, Tomoaki; Imazu, Susumu; Gao Jianqing; Hayashi, Kazuyuki; Tsuda, Yasuhiro; Shimokawa, Mariko; Sugita, Toshiki; Niwa, Takako; Oda, Atushi; Akashi, Mitsuru; Tsutsumi, Yasuo; Mayumi, Tadanori; Nakagawa, Shinsaku

    2004-01-01

    In an attempt to enhance the immunological efficacy of genetic immunization, we investigated a new biological means for delivering antigen gene directly to the cytoplasm via membrane fusion. In this context, we investigated fusogenic liposome (FL) encapsulating DNA as a possible genetic immunization vehicle. RT-PCR analysis indicated that a FL could introduce and express encapsulating OVA gene efficiently and rapidly in vitro. Consistent with this observation, an in vitro assay showed that FL-mediated antigen-gene delivery can induce potent presentation of antigen via the MHC class I-dependent pathway. Accordingly, immunization with FL containing the OVA-gene induced potent OVA-specific Th1 and Th2 cytokine production. Additionally, OVA-specific CTL responses and antibody production were also observed in systemic compartments including the spleen, upon immunization with the OVA-gene encapsulating FL. These findings suggest that FL is an effective genetic immunization carrier system for the stimulation of antigen-specific immune responses against its encoding antigen

  8. N-Trimethyl chitosan (TMC) nanoparticles loaded with influenza subunit antigen for intranasal vaccination : Biological properties and immunogenicity in a mouse model

    NARCIS (Netherlands)

    Amidi, Maryam; Romeijn, Stefan G.; Verhoef, J. Coos; Junginger, Hans E.; Bungener, Laura; Huckriede, Anke; Crommelin, Daan J. A.; Jiskoot, Wim

    2007-01-01

    In this study, the potential of N-trimethyl chitosan (TMC) nanoparticles as a carrier system for the nasal delivery of a monovalent influenza subunit vaccine was investigated. The antigen-loaded nanoparticles were prepared by mixing a solution containing TMC and monovalent influenza A subunit H3N2

  9. Prevalence and sequence variations of the genes encoding the five antigens included in the novel 5CVMB vaccine covering group B meningococcal disease.

    Science.gov (United States)

    Jacobsson, Susanne; Hedberg, Sara Thulin; Mölling, Paula; Unemo, Magnus; Comanducci, Maurizio; Rappuoli, Rino; Olcén, Per

    2009-03-04

    During the recent years, projects are in progress for designing broad-range non-capsular-based meningococcal vaccines, covering also serogroup B isolates. We have examined three genes encoding antigens (NadA, GNA1030 and GNA2091) included in a novel vaccine, i.e. the 5 Component Vaccine against Meningococcus B (5CVMB), in terms of gene prevalence and sequence variations. These data were combined with the results from a similar study, examining the two additional antigens included in the 5CVMB (fHbp and GNA2132). nadA and fHbp v. 1 were present in 38% (n=36), respectively 71% (n=67) of the isolates, whereas gna2132, gna1030 and gna2091 were present in all the Neisseria meningitidis isolates tested (n=95). The level of amino acid conservation was relatively high in GNA1030 (93%), GNA2091 (92%), and within the main variants of NadA and fHbp. GNA2132 (54% of the amino acids conserved) appeared to be the most diversified antigen. Consequently, the theoretical coverage of the 5CVMB antigens and the feasibility to use these in a broad-range meningococcal vaccine is appealing.

  10. The administration route is decisive for the ability of the vaccine adjuvant CAF09 to induce antigen-specific CD8(+) T-cell responses

    DEFF Research Database (Denmark)

    Schmidt, Signe Tandrup; Khadke, Swapnil; Korsholm, Karen Smith

    2016-01-01

    A prerequisite for vaccine-mediated induction of CD8(+) T-cell responses is the targeting of dendritic cell (DC) subsets specifically capable of cross-presenting antigen epitopes to CD8(+) T cells. Administration of a number of cationic adjuvants via the intraperitoneal (i.p.) route has been show...

  11. Improving the malaria transmission-blocking activity of a Plasmodium falciparum 48/45 based vaccine antigen by SpyTag/SpyCatcher mediated virus-like display

    DEFF Research Database (Denmark)

    Singh, Susheel K; Thrane, Susan; Janitzek, Christoph M

    2017-01-01

    Malaria is a devastating disease caused by Plasmodium parasites, resulting in almost 0.5 million deaths per year. The Pfs48/45 protein exposed on the P. falciparum sexual stages is one of the most advanced antigen candidates for a transmission-blocking (TB) vaccine in the clinical pipeline. However...

  12. Structure-activity-based design of a synthetic malaria peptide eliciting sporozoite inhibitory antibodies in a virosomal formulation.

    NARCIS (Netherlands)

    Okitsu, S.L.; Kienzl, U.; Moehle, K.; Silvie, O.; Peduzzi, E.; Mueller, M.S.; Sauerwein, R.W.; Matile, H.; Zurbriggen, R.; Mazier, D.; Robinson, J.A.; Pluschke, G.

    2007-01-01

    The circumsporozoite protein (CSP) of Plasmodium falciparum is a leading candidate antigen for inclusion in a malaria subunit vaccine. We describe here the design of a conformationally constrained synthetic peptide, designated UK-39, which has structural and antigenic similarity to the NPNA-repeat

  13. Induction of anti-HBs in HB vaccine nonresponders in vivo by hepatitis B surface antigen-pulsed blood dendritic cells.

    Science.gov (United States)

    Fazle Akbar, Sk Md; Furukawa, Shinya; Yoshida, Osamu; Hiasa, Yoichi; Horiike, Norio; Onji, Morikazu

    2007-07-01

    Antigen-pulsed dendritic cells (DCs) are now used for treatment of patients with cancers, however, the efficacy of these DCs has never been evaluated for prophylactic purposes. The aim of this study was (1) to prepare hepatitis B surface antigen (HBsAg)-pulsed human blood DCs, (2) to assess immunogenicity of HBsAg-pulsed DCs in vitro and (3) to evaluate the efficacy of HBsAg-pulsed DCs in hepatitis B (HB) vaccine nonresponders. Human peripheral blood DCs were cultured with HBsAg to prepare HBsAg-pulsed DCs. The expression of immunogenic epitopes of HBsAg on HBsAg-pulsed DCs was assessed in vitro. Finally, HBsAg-pulsed DCs were administered, intradermally to six HB vaccine nonresponders and the levels of antibody to HBsAg (anti-HBs) in the sera were assessed. HB vaccine nonresponders did not exhibit features of immediate, early or delayed adverse reactions due to administration of HBsAg-pulsed DCs. Anti-HBs were detected in the sera of all HB vaccine nonresponders within 28 days after administration of HBsAg-pulsed DCs. This study opens a new field of application of antigen-pulsed DCs for prophylactic purposes when adequate levels of protective antibody cannot be induced by traditional vaccination approaches.

  14. Molecular insights into the interaction between Plasmodium falciparum apical membrane antigen 1 and an invasion-inhibitory peptide.

    Directory of Open Access Journals (Sweden)

    Geqing Wang

    Full Text Available Apical membrane antigen 1 (AMA1 of the human malaria parasite Plasmodium falciparum has been implicated in invasion of the host erythrocyte. It interacts with malarial rhoptry neck (RON proteins in the moving junction that forms between the host cell and the invading parasite. Agents that block this interaction inhibit invasion and may serve as promising leads for anti-malarial drug development. The invasion-inhibitory peptide R1 binds to a hydrophobic cleft on AMA1, which is an attractive target site for small molecules that block parasite invasion. In this work, truncation and mutational analyses show that Phe5-Phe9, Phe12 and Arg15 in R1 are the most important residues for high affinity binding to AMA1. These residues interact with two well-defined binding hot spots on AMA1. Computational solvent mapping reveals that one of these hot spots is suitable for small molecule targeting. We also confirm that R1 in solution binds to AMA1 with 1:1 stoichiometry and adopts a secondary structure consistent with the major form of R1 observed in the crystal structure of the complex. Our results provide a basis for designing high affinity inhibitors of the AMA1-RON2 interaction.

  15. 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.

  16. Genetic diversity of G1P[8] rotavirus VP7 and VP8* antigens in Finland over a 20-year period: No evidence for selection pressure by universal mass vaccination with RotaTeq® vaccine.

    Science.gov (United States)

    Hemming, Maria; Vesikari, Timo

    2013-10-01

    Two live-attenuated oral vaccines (Rotarix™ and Rotateq®) against rotavirus gastroenteritis were licensed in 2006 and have been introduced into National Immunization Programs (NIPs) of several countries. Large scale use of rotavirus vaccines might cause antigenic pressure on circulating rotavirus types or lead to selection of new rotaviruses thus decreasing vaccine efficacy. We examined the nucleotide and amino acid sequences of the surface proteins VP7 and VP4 (cleaved to VP8(*) and VP5(*)) of a total of 108 G1P[8] rotavirus strains collected over a 20-year period from 1992, including the years 2006-2009 when rotavirus vaccine (mainly Rotarix™) was available, and the years 2009-2012 after implementation of RotaTeq® vaccine into the NIP of Finland. In G1 VP7 no changes at amino acid level were observed. In VP8(*) periodical fluctuation of the sublineage over the study period was found with multiple changes both at nucleotide and amino acid levels. Most amino acid changes were in the dominant antigenic epitopes of VP8(*). A change in VP8(*) sublineage occurred between 2008 and 2009, with a temporal correlation to the use of Rotarix™ up to 30% coverage in the period. In contrast, no antigenic changes in the VP8(*) protein appeared to be correlated to the exclusive use of RotaTeq® vaccine after 2009. Nevertheless, long-term surveillance of antigenic changes in VP4 and also VP7 proteins in wild-type rotavirus strains is warranted in countries with large scale use of the currently licensed live oral rotavirus vaccines. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Selection of a novel anti-nicotine vaccine: influence of antigen design on antibody function in mice.

    Directory of Open Access Journals (Sweden)

    David C Pryde

    Full Text Available Anti-nicotine vaccines may aid smoking cessation via the induction of anti-nicotine antibodies (Ab which reduce nicotine entering the brain, and hence the associated reward. Ab function depends on both the quantity (titer and the quality (affinity of the Ab. Anti-nicotine vaccines tested previously in clinical studies had poor efficacy despite high Ab titer, and this may be due to inadequate function if Ab of low affinity were induced. In this study, we designed and synthesized a series of novel nicotine-like haptens which were all linked to diphtheria toxoid (DT as carrier, but which differed in the site of attachment of linker to nicotine, the nature of linker used, and the handle used to attach the hapten to DT. The resulting hapten conjugates were evaluated in a mouse model, using CpG (a TLR9 agonist and aluminum hydroxide (Al(OH3 as adjuvants, whereby Ab titers, affinity and function were evaluated using a radiolabeled nicotine challenge model. A series of additional linkers varying in length, rigidity and polarity were used with a single hapten to generate additional DT-conjugates, which were also tested in mice. Conjugates made with different haptens resulted in various titers of anti-nicotine Ab. Several haptens gave similarly high Ab titers, but among these, Ab affinity and hence function varied considerably. Linker also influenced Ab titer, affinity and function. These results demonstrate that immune responses induced in mice by nicotine-conjugate antigens are greatly influenced by hapten design including site of attachment of linker to nicotine, the nature of linker used, and the handle used to attach the hapten to DT. While both Ab titer and affinity contributed to function, affinity was more sensitive to antigen differences.

  18. Safety, immune and clinical responses in metastatic melanoma patients vaccinated with a long peptide derived from indoleamine 2,3-dioxygenase in combination with ipilimumab

    DEFF Research Database (Denmark)

    Bjørn, Jon; Iversen, Trine Zeeberg; Nitschke, Nikolaj Juul

    2016-01-01

    antibody ipilimumab (ipi). METHODS: Ten patients with metastatic melanoma participated in a phase I first-in-human clinical study assessing safety of combining ipi with a 21-mer synthetic peptide vaccine from IDO denoted IDOlong. Secondary and tertiary end points included vaccine and clinical response......BACKGROUND AIM: Indoleamine 2,3-dioxygenase (IDO) is an emerging new target in cancer therapy that can be targeted with active immunotherapy (e.g. through peptide vaccination). Furthermore, IDO has been identified as a key mechanism underlying resistance to treatment with the checkpoint blocking....... RESULTS: Treatment was generally safe and well tolerated. Vaccine related adverse reactions included grade I and II erythema, oedema and pruritus at the vaccination site, which were manageable with mild topical corticosteroids. One patient developed presumed ipi-induced colitis. It initially responded...

  19. Phase I study utilizing a novel antigen-presenting cell-targeted vaccine with Toll-like receptor stimulation to induce immunity to self-antigens in cancer patients.

    Science.gov (United States)

    Morse, Michael A; Chapman, Robert; Powderly, John; Blackwell, Kimberly; Keler, Tibor; Green, Jennifer; Riggs, Renee; He, Li-Zhen; Ramakrishna, Venky; Vitale, Laura; Zhao, Biwei; Butler, Stephen A; Hobeika, Amy; Osada, Takuya; Davis, Thomas; Clay, Timothy; Lyerly, H Kim

    2011-07-15

    The use of tumor-derived proteins as cancer vaccines is complicated by tolerance to these self-antigens. Tolerance may be broken by immunization with activated, autologous, ex vivo generated and antigen-loaded, antigen-presenting cells (APC); however, targeting tumor antigen directly to APC in vivo would be a less complicated strategy. We wished to test whether targeted delivery of an otherwise poorly immunogenic, soluble antigen to APC through their mannose receptors (MR) would induce clinically relevant immunity. Two phase I studies were conducted with CDX-1307, a vaccine composed of human chorionic gonadotropin beta-chain (hCG-β) fused to an MR-specific monoclonal antibody, administered either locally (intradermally) or systemically (intravenously) in patients with advanced epithelial malignancies. An initial dose escalation of single-agent CDX-1307 was followed by additional cohorts of CDX-1307 combined with granulocyte-macrophage colony-stimulating factor (GM-CSF) and the Toll-like receptor (TLR) 3 agonist polyinosinic-polycytidylic acid (poly-ICLC) and TLR7/8 agonist resiquimod to activate the APC. CDX-1307 induced consistent humoral and T-cell responses to hCG-β when coadministered with TLR agonists. Greater immune responses and clinical benefit, including the longest duration of stable disease, were observed with immunization combined with local TLR agonists. Immune responses were induced equally efficiently in patients with elevated and nonelevated levels of serum hCG-β. Antibodies within the serum of vaccinated participants had tumor suppressive function in vitro. Toxicity consisted chiefly of mild injection site reactions. APC targeting and activation induce adaptive immunity against poorly immunogenic self-antigens which has implications for enhancing the efficacy of cancer immunotherapy.

  20. Safety and immunogenicity of a combined hepatitis B virus-Haemophilus influenzae type B vaccine comprising a synthetic antigen in healthy adults.

    Science.gov (United States)

    Aguilar-Betancourt, Arístides; González-Delgado, Carlos Alberto; Cinza-Estévez, Z; Martínez-Cabrera, Jesus; Véliz-Ríos, Gloria; Alemán-Zaldívar, Regis; Alonso-Martínez, M I; Lago-Baños, M; Puble-Alvarez, N; Delahanty-Fernandez, A; Juvier-Madrazo, A I; Ortega-León, D; Olivera-Ruano, L; Correa-Fernández, A; Abreu-Reyes, D; Soto-Mestre, E; Pérez-Pérez, M V; Figueroa-Baile, N; Pérez, L Hernandez; Rodríguez-Silva, A; Martínez-Díaz, E; Guillén-Nieto, G E; Muzio-González, Verena L

    2008-01-01

    The combined HB-Hib vaccine candidate Hebervac HB-Hib (CIGB, La Habana), comprising recombinant HBsAg and tetanus toxoid conjugate synthetic PRP antigens has shown to be highly immunogenic in animal models. A phase I open, controlled, randomized clinical trial was carried out to assess the safety and immunogenicity profile of this bivalent vaccine in 25 healthy adults who were positive for antibody to HBsAg (anti-HBs). The trial was performed according to Good Clinical Practices and Guidelines. Volunteers were randomly allocated to receive the combined vaccine or simultaneous administration of HB vaccine Heberbiovac-HB and Hib vaccine QuimiHib (CIGB, La Habana). All individuals were intramuscularly immunized with a unique dose of 10 microg HBsAg plus 10 microg conjugated synthetic PRP. Adverse events were actively recorded after vaccine administration. Total anti-HBs and IgG anti-PRP antibody titers were evaluated using commercial ELISA kits at baseline and 30 days post-vaccination. The combined vaccine candidate was safe and well tolerated. The most common adverse reactions were local pain, febricula, fever and local erythema. These reactions were all mild in intensity and resolved without medical treatment. Adverse events were mostly reported during the first 6-72 hours post-vaccination. There were no serious adverse events during the study. No severe or unexpected events were either recorded during the trial. The combined vaccine elicited an anti-HBs and anti-PRP booster response in 100% of subjects at day 30 of the immunization schedule. Anti-HBs and anti-PRP antibody levels had at least a two-fold increase compared to baseline sera. Even more, anti-HBs antibody titer showed a four-fold increase in 100% of volunteers in the study group. The results indicate that the combined HB-Hib vaccine produces increased antibody levels in healthy adults who have previously been exposed to these two antigens. To our knowledge, this is the first demonstration of safety and

  1. Genome-wide screening and identification of antigens for rickettsial vaccine development

    Science.gov (United States)

    The capacity to identify immunogens for vaccine development by genome-wide screening has been markedly enhanced by the availability of complete microbial genome sequences coupled to rapid proteomic and bioinformatic analysis. Critical to this genome-wide screening is in vivo testing in the context o...

  2. Silk fibroin-antigenic peptides-YVO{sub 4}:Eu{sup 3+} nanostructured thin films as sensors for hepatitis C

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Lais R. [Institute of Chemistry, São Paulo State University, UNESP, CP355, Araraquara, SP 14801-970 (Brazil); Moraes, Marli L. [Institute of Science and Technology, Federal University of São Paulo, UNIFESP, São José dos Campos, SP 12231-280 (Brazil); Nigoghossian, Karina; Peres, Maristela F.S. [Institute of Chemistry, São Paulo State University, UNESP, CP355, Araraquara, SP 14801-970 (Brazil); Ribeiro, Sidney J.L., E-mail: sidney@iq.unesp.br [Institute of Chemistry, São Paulo State University, UNESP, CP355, Araraquara, SP 14801-970 (Brazil)

    2016-02-15

    Nanostructured films prepared by Layer-by-Layer technique and containing silk fibroin, antigenic peptide NS5A-1 derived from hepatitis C virus (HCV) NS5A protein and YVO{sub 4}:Eu{sup 3+} luminescent nanoparticles, were utilized in sensing of hepatitis C. Detection system exploits the biorecognition between the antibody anti-HCV and the antigenic peptide NS5A-1 through changes in luminescence properties. Films deposition was monitored by UV–vis Absorption and Fluorescence Spectroscopy measurements at each bilayer deposited. The Eu{sup 3+} luminescence properties were evaluated in the presence of anti-HCV for optical detection of specific antibody and anti-HIV used as negative control. Significant changes in luminescence were observed in the presence of anti-HCV concentrations. A new immunosensor platform is proposed for optical detection of hepatitis C. - Highlights: • LbL films composed of silk fibroin, antigenic peptide NS5A-1 and YVO{sub 4}:Eu{sup 3+} NPs. • PL is sensitive to the presence of anti-HCV. • A new imunosensor platform is therefore proposed.

  3. A virosomal formulated Her-2/neu multi-peptide vaccine induces Her-2/neu-specific immune responses in patients with metastatic breast cancer: a phase I study.

    Science.gov (United States)

    Wiedermann, Ursula; Wiltschke, C; Jasinska, J; Kundi, M; Zurbriggen, R; Garner-Spitzer, E; Bartsch, R; Steger, G; Pehamberger, H; Scheiner, O; Zielinski, C C

    2010-02-01

    We have previously shown in mice that vaccination with three Her-2-peptides representing B-cell epitopes of the extracellular domain of Her-2/neu induces Her-2/neu-specific IgG antibodies with strong anti-tumor activity in vitro and in vivo. We have now finalized a phase I clinical trial with an anti-Her-2/neu vaccine-construct of immunopotentiating reconstituted influenza virosomes with the three peptides in patients with metastatic breast cancer (MBC). Ten MBC patients with low protein overexpression of Her-2/neu of MBC (+ or ++ upon immunohistochemistry, FISH negative) and positive hormone receptor status were enrolled in a single center phase I study. The virosomal formulated vaccine, consisting of 10 microg/peptide, was intramuscularly applied three times on days 1, 28, and 56. The primary endpoint of the study, which lasted 12 weeks, was safety, the secondary endpoint immunogenicity. Local erythema at the injection site was the only vaccine-related side effect occurring in four patients. In 8 of 10 patients an increase in peptide-specific antibody titer measured by ELISA was found. Importantly, the induced antibodies were also directed against the native Her-2/neu protein. Cellular immune responses, as measured by in vitro production of IL-2, IFN-c, and TNF-a of PBMCs showed a marked increase after vaccination in the majority of vaccinees. Notably, the number of CD4+CD25+Foxp3+T regulatory cells, which were significantly increased compared to healthy controls prior to vaccination, was markedly reduced following vaccination. In all, the immunological responses after vaccination indicated that the patients in stage IV of disease were immunocompetent and susceptible to vaccination. The Her-2/neu multipeptide vaccine was safe, well tolerated and effective in overcoming immunological tolerance to Her-2/neu. The induction of anti-Her-2-specific antibodies could result in clinical benefit comparable to passive anti-Her-2 antibody therapy.

  4. Microneedle arrays coated with charge reversal pH-sensitive copolymers improve antigen presenting cells-homing DNA vaccine delivery and immune responses.

    Science.gov (United States)

    Duong, Huu Thuy Trang; Kim, Nak Won; Thambi, Thavasyappan; Giang Phan, V H; Lee, Min Sang; Yin, Yue; Jeong, Ji Hoon; Lee, Doo Sung

    2018-01-10

    Successful delivery of a DNA vaccine to antigen-presenting cells and their subsequent stimulation of CD4 + and CD8 + T cell immunity remains an inefficient process. In general, the delivery of prophylactic vaccines is mainly mired by low transfection efficacy, poor immunogenicity, and safety issues from the materials employed. Currently, several strategies have been exploited to improve immunogenicity, but an effective strategy for safe and pain-free delivery of DNA vaccines is complicated. Herein, we report the rapid delivery of polyplex-based DNA vaccines using microneedle arrays coated with a polyelectrolyte multilayer assembly of charge reversal pH-responsive copolymer and heparin. The charge reversal pH-responsive copolymer, composed of oligo(sulfamethazine)-b-poly(ethylene glycol)-b-poly(amino urethane) (OSM-b-PEG-b-PAEU), was used as a triggering layer in the polyelectrolyte multilayer assembly on microneedles. Charge reversal characteristics of this copolymer, that is, the OSM-b-PEG-b-PAEU copolymer exhibit, positive charge at low pH (pH4.03) and becoming negative charge when exposed to physiological pH conditions (pH7.4), allowing the facile assembly and disassembly of polyelectrolyte multilayers. The electrostatic repulsion between heparin and OSM-b-PEG-b-PAEU charge reversal copolymer triggered the release of DNA vaccines. DNA vaccines laden on microneedles are effectively transfected into RAW 264.7 macrophage cells in vitro. Vaccination of BALB/c mice by DNA vaccine-loaded microneedle arrays coated with a polyelectrolyte multilayer generated antigen-specific robust immune responses. These findings provide potential strategy of charge reversal pH-responsive copolymers coated microneedles for DNA vaccine delivery. Copyright © 2017. Published by Elsevier B.V.

  5. 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

    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 vector...... encoding GP linked to Ii (Ad-Ii-GP) resulted in complete protection against GP33-expressing B16.F10 tumors. Therapeutic vaccination with Ad-Ii-GP delayed tumor growth by more than 2 wk compared with sham vaccination. Notably, therapeutic vaccination with the linked vaccine was significantly better than...... the tumor degradation. Finally, Ad-Ii-GP but not Ad-GP vaccination can break the immunological non-reactivity in GP transgenic mice indicating that our vaccine strategy will prove efficient also against endogenous tumor antigens....

  6. Characterisation of peptide microarrays for studying antibody-antigen binding using surface plasmon resonance imagery.

    Directory of Open Access Journals (Sweden)

    Claude Nogues

    Full Text Available BACKGROUND: Non-specific binding to biosensor surfaces is a major obstacle to quantitative analysis of selective retention of analytes at immobilized target molecules. Although a range of chemical antifouling monolayers has been developed to address this problem, many macromolecular interactions still remain refractory to analysis due to the prevalent high degree of non-specific binding. We describe how we use the dynamic process of the formation of self assembling monolayers and optimise physical and chemical properties thus reducing considerably non-specific binding and allowing analysis of specific binding of analytes to immobilized target molecules. METHODOLOGY/PRINCIPAL FINDINGS: We illustrate this approach by the production of specific protein arrays for the analysis of interactions between the 65kDa isoform of human glutamate decarboxylase (GAD65 and a human monoclonal antibody. Our data illustrate that we have effectively eliminated non-specific interactions with the surface containing the immobilised GAD65 molecules. The findings have several implications. First, this approach obviates the dubious process of background subtraction and gives access to more accurate kinetic and equilibrium values that are no longer contaminated by multiphase non-specific binding. Second, an enhanced signal to noise ratio increases not only the sensitivity but also confidence in the use of SPR to generate kinetic constants that may then be inserted into van't Hoff type analyses to provide comparative DeltaG, DeltaS and DeltaH values, making this an efficient, rapid and competitive alternative to ITC measurements used in drug and macromolecular-interaction mechanistic studies. Third, the accuracy of the measurements allows the application of more intricate interaction models than simple Langmuir monophasic binding. CONCLUSIONS: The detection and measurement of antibody binding by the type 1 diabetes autoantigen GAD65 represents an example of an antibody-antigen

  7. Identification of protective postexposure mycobacterial vaccine antigens using an immunosuppression-based reactivation model in the zebrafish

    Directory of Open Access Journals (Sweden)

    Henna Myllymäki

    2018-03-01

    Full Text Available Roughly one third of the human population carries a latent Mycobacterium tuberculosis infection, with a 5-10% lifetime risk of reactivation to active tuberculosis and further spreading the disease. The mechanisms leading to the reactivation of a latent Mycobacterium tuberculosis infection are insufficiently understood. Here, we used a natural fish pathogen, Mycobacterium marinum, to model the reactivation of a mycobacterial infection in the adult zebrafish (Danio rerio. A low-dose intraperitoneal injection (∼40 colony-forming units led to a latent infection, with mycobacteria found in well-organized granulomas surrounded by a thick layer of fibrous tissue. A latent infection could be reactivated by oral dexamethasone treatment, which led to disruption of the granuloma structures and dissemination of bacteria. This was associated with the depletion of lymphocytes, especially CD4+ T cells. Using this model, we verified that ethambutol is effective against an active disease but not a latent infection. In addition, we screened 15 mycobacterial antigens as postexposure DNA vaccines, of which RpfB and MMAR_4207 reduced bacterial burdens upon reactivation, as did the Ag85-ESAT-6 combination. In conclusion, the adult zebrafish-M. marinum infection model provides a feasible tool for examining the mechanisms of reactivation in mycobacterial infections, and for screening vaccine and drug candidates. This article has an associated First Person interview with the first author of the paper.

  8. Molecular definition of multiple sites of antibody inhibition of malaria transmission-blocking vaccine antigen Pfs25.

    Science.gov (United States)

    Scally, Stephen W; McLeod, Brandon; Bosch, Alexandre; Miura, Kazutoyo; Liang, Qi; Carroll, Sean; Reponen, Sini; Nguyen, Ngan; Giladi, Eldar; Rämisch, Sebastian; Yusibov, Vidadi; Bradley, Allan; Lemiale, Franck; Schief, William R; Emerling, Daniel; Kellam, Paul; King, C Richter; Julien, Jean-Philippe

    2017-11-16

    The Plasmodium falciparum Pfs25 protein (Pfs25) is a leading malaria transmission-blocking vaccine antigen. Pfs25 vaccination is intended to elicit antibodies that inhibit parasite development when ingested by Anopheles mosquitoes during blood meals. The Pfs25 three-dimensional structure has remained elusive, hampering a molecular understanding of its function and limiting immunogen design. We report six crystal structures of Pfs25 in complex with antibodies elicited by immunization via Pfs25 virus-like particles in human immunoglobulin loci transgenic mice. Our structural findings reveal the fine specificities associated with two distinct immunogenic sites on Pfs25. Importantly, one of these sites broadly overlaps with the epitope of the well-known 4B7 mouse antibody, which can be targeted simultaneously by antibodies that target a non-overlapping site to additively increase parasite inhibition. Our molecular characterization of inhibitory antibodies informs on the natural disposition of Pfs25 on the surface of ookinetes and provides the structural blueprints to design next-generation immunogens.

  9. 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.

  10. Towards biocompatible vaccine delivery systems: interactions of colloidal PECs based on polysaccharides with HIV-1 p24 antigen.

    Science.gov (United States)

    Drogoz, Alexandre; Munier, Séverine; Verrier, Bernard; David, Laurent; Domard, Alain; Delair, Thierry

    2008-02-01

    This work reports on the interactions of a model protein (p24, the capside protein of HIV-1 virus) with colloids obtained from polyelectrolyte complexes (PECs) involving two polysaccharides: chitosan and dextran sulfate (DS). The PECs were elaborated by a one-shot addition of default amounts of one counterpart to the polymer in excess. Depending on the nature of the excess polyelectrolyte, the submicrometric colloid was either positively or negatively charged. HIV-1 capsid p24 protein was chosen as antigen, the ultrapure form, lipopolysaccharide-free (endotoxin-, vaccine grade) was used in most experiments, as the level of purity of the protein had a great impact on the immobilization process. p24 sorption kinetics, isotherms, and loading capacities were investigated for positively and negatively charged particles of chitosans and dextran sulfates differing in degrees of polymerization (DP) or acetylation (DA). Compared with the positive particles, negatively charged colloids had higher binding capacities, faster kinetics, and a better stability of the adsorbed p24. Capacities up to 600 mg x g(-1) (protein-colloid) were obtained, suggesting that the protein interacted within the shell of the particles. Small-angle X-rays scattering experiments confirmed this hypothesis. Finally, the immunogenicity of the p24-covered particles was assessed for vaccine purposes in mice. The antibody titers obtained with immobilized p24 was dose dependent and in the same range as for Freund's adjuvant, a gold standard for humoral responses.

  11. Human Asymptomatic Epitope Peptide/CXCL10-Based Prime/Pull Vaccine Induces Herpes Simplex Virus-Specific Gamma Interferon-Positive CD107+ CD8+ T Cells That Infiltrate the Cornea and Trigeminal Ganglia of Humanized HLA Transgenic Rabbits and Protect against Ocular Herpes Challenge.

    Science.gov (United States)

    Khan, Arif A; Srivastava, Ruchi; Vahed, Hawa; Roy, Soumyabrata; Walia, Sager S; Kim, Grace J; Fouladi, Mona A; Yamada, Taikun; Ly, Vincent T; Lam, Cynthia; Lou, Anthony; Nguyen, Vivianna; Boldbaatar, Undariya; Geertsema, Roger; Fraser, Nigel W; BenMohamed, Lbachir

    2018-06-13

    Herpes simplex virus 1 (HSV-1) is a prevalent human pathogen that infects the cornea causing potentially blinding herpetic disease. A clinical herpes vaccine is still lacking. In the present study, a novel prime/pull vaccine was tested in Human Leukocyte Antigen- (HLA-) transgenic rabbit model of ocular herpes (HLA Tg rabbit). Three asymptomatic (ASYMP) peptide epitopes were selected from the HSV-1 membrane glycoprotein C (UL44 400-408 ), the DNA replication binding helicase (UL9 196-204 ), and the tegument protein (UL25 572-580 ), all preferentially recognized by CD8 + T cells from "naturally protected" HSV-1-seropositive healthy ASYMP individuals (who never had recurrent corneal herpetic disease). HLA Tg rabbits were immunized with a mixture of these three ASYMP CD8 + T cell peptide epitopes (UL44 400-408 , UL9 196-204 and UL25 572-580 ), delivered subcutaneously with CpG 2007 adjuvant (prime). Fifteen days later, half of the rabbits received a topical ocular treatment with a recombinant neurotropic AAV8 vector, expressing the T cell-attracting CXCL10 chemokine (pull). The frequency, function of HSV-specific CD8 + T cells induced by the prime/pull vaccine were assessed in peripheral blood, cornea, and trigeminal ganglia (TG). Compared to peptides alone, the peptides/CXCL10 prime/pull vaccine generated frequent polyfunctional gamma interferon-positive (IFN-γ + ) CD107 + CD8 + T cells that infiltrated both the cornea and TG. CD8 + T cells mobilization into cornea and TG of prime/pull- vaccinated rabbits was associated with a significant reduction in corneal herpes infection and disease following an ocular HSV-1 challenge (McKrae). These findings draw attention to the novel prime/pull vaccine strategy to mobilize anti-viral CD8 + T cells into tissues protecting them against herpes infection and disease. IMPORTANCE There is an urgent need for a vaccine against widespread herpes simplex virus infections. The present study demonstrates that immunization of HLA

  12. A phase I study of combination vaccine treatment of five therapeutic epitope-peptides for metastatic colorectal cancer; safety, immunological response, and clinical outcome.

    Science.gov (United States)

    Hazama, Shoichi; Nakamura, Yusuke; Takenouchi, Hiroko; Suzuki, Nobuaki; Tsunedomi, Ryouichi; Inoue, Yuka; Tokuhisa, Yoshihiro; Iizuka, Norio; Yoshino, Shigefumi; Takeda, Kazuyoshi; Shinozaki, Hirokazu; Kamiya, Akira; Furukawa, Hiroyuki; Oka, Masaaki

    2014-03-10

    To evaluate the safety of combination vaccine treatment of multiple peptides, phase I clinical trial was conducted for patients with advanced colorectal cancer using five novel HLA-A*2402-restricted peptides, three peptides derived from oncoantigens, ring finger protein 43 (RNF43), 34 kDa-translocase of the outer mitochondrial membrane (TOMM34), and insulin-like growth factor-II mRNA binding protein 3 (KOC1), and the remaining two from angiogenesis factors, vascular endothelial growth factor receptor 1 (VEGFR1) and VEGFR2. Eighteen HLA- A*2402-positive colorectal cancer patients who had failed to standard therapy were enrolled in this study. 0.5 mg, 1.0 mg or 3.0 mg each of the peptides was mixed with incomplete Freund's adjuvant and then subcutaneously injected at five separated sites once a week. We also examined possible effect of a single site injection of "the cocktail of 5 peptides" on the immunological responses. ELISPOT assay was performed before and after vaccinations in the schedule of every 4 weeks. The vaccine treatment using multiple peptides was well tolerated without any severe treatment-associated systemic adverse events. Dose-dependent induction of peptide-specific cytotoxic T lymphocytes was observed. The single injection of "peptides cocktail" did not diminish the immunological responses. Regarding the clinical outcome, one patient achieved complete response and 6 patients revealed stable disease for 4 to 7 months. The median overall survival time (MST) was 13.5 months. Patients, in which we detected induction of cytotoxic T lymphocytes specific to 3 or more peptides, revealed significantly better prognosis (MST; 27.8 months) than those with poorer immune responses (MST; 3.7 months) (p = 0.032). Our cancer vaccine treatment using multiple peptides is a promising approach for advanced colorectal cancer with the minimum risk of systemic adverse reactions. UMIN-CTR number UMIN000004948.

  13. Proteomics-Based Characterization of the Humoral Immune Response in Sporotrichosis: Toward Discovery of Potential Diagnostic and Vaccine Antigens.

    Science.gov (United States)

    Rodrigues, Anderson Messias; Fernandes, Geisa Ferreira; Araujo, Leticia Mendes; Della Terra, Paula Portella; dos Santos, Priscila Oliveira; Pereira, Sandro Antonio; Schubach, Tânia Maria Pacheco; Burger, Eva; Lopes-Bezerra, Leila Maria; de Camargo, Zoilo Pires

    2015-01-01

    Sporothrix schenckii and associated species are agents of human and animal sporotrichosis that cause large sapronoses and zoonoses worldwide. Epidemiological surveillance has highlighted an overwhelming occurrence of the highly pathogenic fungus Sporothrix brasiliensis during feline outbreaks, leading to massive transmissions to humans. Early diagnosis of feline sporotrichosis by demonstrating the presence of a surrogate marker of infection can have a key role for selecting appropriate disease control measures and minimizing zoonotic transmission to humans. We explored the presence and diversity of serum antibodies (IgG) specific against Sporothrix antigens in cats with sporotrichosis and evaluated the utility of these antibodies for serodiagnosis. Antigen profiling included protein extracts from the closest known relatives S. brasiliensis and S. schenckii. Enzyme-linked immunosorbent assays and immunoblotting enabled us to characterize the major antigens of feline sporotrichosis from sera from cats with sporotrichosis (n = 49), healthy cats (n = 19), and cats with other diseases (n = 20). Enzyme-linked immunosorbent assay-based quantitation of anti-Sporothrix IgG exhibited high sensitivity and specificity in cats with sporotrichosis (area under the curve, 1.0; 95% confidence interval, 0.94-1; Psporotrichosis. Two-dimensional immunoblotting revealed six IgG-reactive isoforms of gp60 in the S. brasiliensis proteome, similar to the humoral response found in human sporotrichosis. A convergent IgG-response in various hosts (mice, cats, and humans) has important implications for our understanding of the coevolution of Sporothrix and its warm-blooded hosts. We propose that 3-carboxymuconate cyclase has potential for the serological diagnosis of sporotrichosis and as target for the development of an effective multi-species vaccine against sporotrichosis in animals and humans.

  14. Chimeric peptide containing both B and T cells epitope of tumor-associated antigen L6 enhances anti-tumor effects in HLA-A2 transgenic mice.

    Science.gov (United States)

    Lin, Su-I; Huang, Ming-Hsi; Chang, Yu-Wen; Chen, I-Hua; Roffler, Steve; Chen, Bing-Mae; Sher, Yuh-Pyng; Liu, Shih-Jen

    2016-07-28

    Synthetic peptides are attractive for cancer immunotherapy because of their safety and flexibility. In this report, we identified a new B cell epitope of tumor-associated antigen L6 (TAL6) that could induce antibody-dependent cellular cytotoxicity (ADCC) in vivo. We incorporated the B cell epitope with a cytotoxic T lymphocyte (CTL) and a helper T (Th) epitope to form a chimeric long peptide. We formulated the chimeric peptide with different adjuvants to immunize HLA-A2 transgenic mice and evaluate their immunogenicity. The chimeric peptide formulated with an emulsion type nanoparticle (PELC) adjuvant and a toll-like receptor 9 agonist (CpG ODN) (PELC/CpG) induced the greatest ADCC and CTL responses. The induced anti-tumor immunity inhibited the growth of TAL6-positive cancer cells. Moreover, we observed that immunization with the chimeric peptide inhibited cancer cell migration in vitro and metastasis in vivo. These data suggest that a chimeric peptide containing both B and T cell epitopes of TAL6 formulated with PELC/CpG adjuvant is feasible for cancer immunotherapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Improvement of different vaccine delivery systems for cancer therapy

    Directory of Open Access Journals (Sweden)

    Safaiyan Shima

    2011-01-01

    Full Text Available Abstract Cancer vaccines are the promising tools in the hands of the clinical oncologist. Many tumor-associated antigens are excellent targets for immune therapy and vaccine design. Optimally designed cancer vaccines should combine the best tumor antigens with the most effective immunotherapy agents and/or delivery strategies to achieve positive clinical results. Various vaccine delivery systems such as different routes of immunization and physical/chemical delivery methods have been used in cancer therapy with the goal to induce immunity against tumor-associated antigens. Two basic delivery approaches including physical delivery to achieve higher levels of antigen production and formulation with microparticles to target antigen-presenting cells (APCs have demonstrated to be effective in animal models. New developments in vaccine delivery systems will improve the efficiency of clinical trials in the near future. Among them, nanoparticles (NPs such as dendrimers, polymeric NPs, metallic NPs, magnetic NPs and quantum dots have emerged as effective vaccine adjuvants for infectious diseases and cancer therapy. Furthermore, cell-penetrating peptides (CPP have been known as attractive carrier having applications in drug delivery, gene transfer and DNA vaccination. This review will focus on the utilization of different vaccine delivery systems for prevention or treatment of cancer. We will discuss their clinical applications and the future prospects for cancer vaccine development.

  16. 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

    2014-10-07

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Antigenicity and diagnostic potential of vaccine candidates in human Chagas disease.

    Directory of Open Access Journals (Sweden)

    Shivali Gupta

    Full Text Available 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.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.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.

  18. Recombinant α-actinin subunit antigens of Trichomonas vaginalis as potential vaccine candidates in protecting against trichomoniasis.

    Science.gov (United States)

    Xie, Yi-Ting; Gao, Jiang-Mei; Wu, Ya-Ping; Tang, Petrus; Hide, Geoff; Lai, De-Hua; Lun, Zhao-Rong

    2017-02-16

    stimulation with the corresponding antigens in vitro. Immunization with both ACT-F and ACT-T could confer partial to complete protection and trigger strong Th1/Th2 mixed humoral and cellular immune responses in the mouse host. This suggested that recombinant α-actinin subunit antigens may be promising vaccine candidates against trichomoniasis.

  19. Vaccination of koalas (Phascolarctos cinereus) with a recombinant chlamydial major outer membrane protein adjuvanted with poly I:C, a host defense peptide and polyphosphazine, elicits strong and long lasting cellular and humoral immune responses.

    Science.gov (United States)

    Khan, Shahneaz Ali; Waugh, Courtney; Rawlinson, Galit; Brumm, Jacqui; Nilsson, Karen; Gerdts, Volker; Potter, Andrew; Polkinghorne, Adam; Beagley, Kenneth; Timms, Peter

    2014-10-07

    Chlamydial infections are wide spread in koalas across their range and a solution to this debilitating disease has been sought for over a decade. Antibiotics are the currently accepted therapeutic measure, but are not an effective treatment due to the asymptomatic nature of some infections and a low efficacy rate. Thus, a vaccine would be an ideal way to address this infectious disease threat in the wild. Previous vaccine trials have used a three-dose regimen; however this is very difficult to apply in the field as it would require multiple capture events, which are stressful and invasive processes for the koala. In addition, it requires skilled koala handlers and a significant monetary investment. To overcome these challenges, in this study we utilized a polyphosphazine based poly I:C and a host defense peptide adjuvant combined with recombinant chlamydial major outer membrane protein (rMOMP) antigen to induce long lasting (54 weeks) cellular and humoral immunity in female koalas with a novel single immunizing dose. Immunized koalas produced a strong IgG response in plasma, as well as at mucosal sites. Moreover, they showed high levels of C. pecorum specific neutralizing antibodies in the plasma as well as vaginal and conjunctival secretions. Lastly, Chlamydia-specific lymphocyte proliferation responses were produced against both whole chlamydial elementary bodies and rMOMP protein, over the 12-month period. The results of this study suggest that a single dose rMOMP vaccine incorporating a poly I:C, host defense peptide and polyphosphazine adjuvant is able to stimulate both arms of the immune system in koalas, thereby providing an alternative to antibiotic treatment and/or a three-dose vaccine regime. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Recent advances in the molecular design of synthetic vaccines

    Science.gov (United States)

    Jones, Lyn H.

    2015-12-01

    Vaccines have typically been prepared using whole organisms. These are normally either attenuated bacteria or viruses that are live but have been altered to reduce their virulence, or pathogens that have been inactivated and effectively killed through exposure to heat or formaldehyde. However, using whole organisms to elicit an immune response introduces the potential for infections arising from a reversion to a virulent form in live pathogens, unproductive reactions to vaccine components or batch-to-batch variability. Synthetic vaccines, in which a molecular antigen is conjugated to a carrier protein, offer the opportunity to circumvent these problems. This Perspective will highlight the progress that has been achieved in developing synthetic vaccines using a variety of molecular antigens. In particular, the different approaches used to develop conjugate vaccines using peptide/proteins, carbohydrates and other small molecule haptens as antigens are compared.

  1. Antigen sparing with adjuvanted inactivated polio vaccine based on Sabin strains.

    Science.gov (United States)

    Westdijk, Janny; Koedam, Patrick; Barro, Mario; Steil, Benjamin P; Collin, Nicolas; Vedvick, Thomas S; Bakker, Wilfried A M; van der Ley, Peter; Kersten, Gideon

    2013-02-18

    Six different adjuvants, each in combination with inactivated polio vaccine (IPV) produced with attenuated Sabin strains (sIPV), were evaluated for their ability to enhance virus neutralizing antibody titres (VNTs) in the rat potency model. The increase of VNTs was on average 3-, 15-, 24-fold with adjuvants after one immunization (serotypes 1, 2, and 3, respectively). Also after a boost immunization the VNTs of adjuvanted sIPV were on average another 7-20-27 times higher than after two inoculations of sIPV without adjuvant. The results indicate that it is feasible to increase the potency of inactivated polio vaccines by using adjuvants. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Development of myiasis vaccine: In vitro detection of immunoprotective responses of peritrophic membrane protein, first instar larva Ll supernatant and pellet antigen of fly Chrysomyia bezziana in sheep

    Directory of Open Access Journals (Sweden)

    Sukarsih

    1999-10-01

    Full Text Available Myiasis control by means of individual treatment of animals which are mainly rised extensively is time consumed and expensive. The alternative way to control this disease by vaccination is considered effective and economically accepted. However the expected vaccine is now still being developed under a collaborative project between CSIRO, Inter-University Centre on Biotechnology-ITB and Research Institute for Veterinary Science and funded by ACIAR. There are several antigens have been identified as vaccine candidates and an in vitro bioassay technique has been developed for assessing the immunoresponses of vaccine in sheep. Three antigens were used for vaccines in this study, these included protein peritrophic membrane (PM, soluble extract (SE and pellet extract (PE of 1st instar larvae of Chrysomya bezziana. Twenty four experimental sheep were divided into 4 groups of 6 animals, 3 groups of animals were injected with PM, SE and PE vaccines with the dose rate of 0.5 g PM/head, 0.8 g PE/head and 4.2 ml LE/head respectively, and the other one group was injected with 4 ml PBS/head as a control group. Vaccination with the same dose was repeated 4 weeks after the 1st vaccination as a booster, and 2 weeks after the booster the sheep were challenged with live larvae, 3 days after challenge animals were killed. Sera were collected at the day of vaccination, 4 weeks after vaccination, 2 weeks after booster, and 3 days after challenge. An in vitro bioassay technique was conducted by culturing 1st instar larvae on five media containing sera collected from each experimental animal. The effects of sera on cultivated larvae were assessed by means of larval weight and larval mortality rate. The results indicated that the growth rate and survival of cultivated larvae in media containing anti-PM sera were significantly lower (P<0.01 compared to the larvae cultivated on media with sera on the day of vaccination. The larval weight depression by anti- PM sera

  3. Successful use of a defined antigen/GM-CSF adjuvant vaccine to treat mucosal leishmaniasis refractory to antimony: a case report

    Directory of Open Access Journals (Sweden)

    Badaro Roberto

    2001-01-01

    Full Text Available Immunotherapy has been proposed as a method to treat mucosal leishmaniasis for many years, but the approach has been hampered by poor definition and variability of antigens used, and results have been inconclusive. We report here a case of antimonial-refractory mucosal leishmaniasis in a 45 year old male who was treated with three single injections (one per month with a cocktail of four Leishmania recombinant antigens selected after documented hypo-responsiveness of the patient to these antigens, plus 50mg of GM-CSF as vaccine adjuvant. Three months after treatment, all lesions had resolved completely and the patient remains without relapse after two years. Side effects of the treatment included only moderate erythema and induration at the injection site after the second and third injections. We conclude that carefully selected microbial antigens and cytokine adjuvant can be successful as immunotherapy for patients with antimonial-refractory mucosal leishmaniasis.

  4. 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

  5. Mycobacterium tuberculosis Latent Antigen Rv2029c from the Multistage DNA Vaccine A39 Drives TH1 Responses via TLR-mediated Macrophage Activation

    Directory of Open Access Journals (Sweden)

    Haibo Su

    2017-11-01

    Full Text Available Targeting of Mycobacterium tuberculosis (MTB latent antigens comprises a crucial strategy for the development of alternative tuberculosis (TB vaccine(s that protects against TB reactivation. Here, we generated a multistage DNA vaccine, A39, containing the early antigens Ag85A and Rv3425 as well as the latency-associated protein Rv2029c, which conferred protective immunity in a pre-exposure mouse model. Moreover, administration of the A39 vaccination after MTB exposure inhibited reactivation and resulted in significantly lower bacterial loads in the lungs and spleen of mice, compared to those in the control population. Subsequently, we investigated the effect of Rv2029c on innate immunity and characterized the molecular details of the interaction of this protein with the host via iTRAQ proteomic and biochemical assay analyses. Rv2029c activated macrophages, triggered the production of pro-inflammatory cytokines, and promoted toll-like receptor/mitogen-activated protein kinase (TLR/MAPK-dependent macrophage apoptosis. Furthermore, Rv2029c treatment enhanced the ability of Mycobacterium bovis Bacillus Calmette-Guérin (BCG-infected macrophages to present antigens to CD4+ T cells in vitro, which correlated with an increase in MHC-II expression. Lastly, Rv2029c-treated macrophages activated T cells, effectively polarized CD4+ and CD8+ T cells to secrete IFN-γ and IL-2, and specifically expanded a population of CD44highCD62LlowCD4+/CD8+ effector/memory cells, indicating that Rv2029c, as a specific recall antigen, contributes to Th1 polarization in T cell immunity. These results suggest that Rv2029c and A39 comprise promising targets for the development of next-generation clinical TB therapeutic vaccines.

  6. Immunogenicity and safety of primary and booster vaccination with 2 investigational formulations of diphtheria, tetanus and Haemophilus influenzae type b antigens in a hexavalent DTPa-HBV-IPV/Hib combination vaccine in comparison with the licensed Infanrix hexa

    Science.gov (United States)

    Vesikari, Timo; Rivera, Luis; Korhonen, Tiina; Ahonen, Anitta; Cheuvart, Brigitte; Hezareh, Marjan; Janssens, Winnie; Mesaros, Narcisa

    2017-01-01

    ABSTRACT Safety and immunogenicity of 2 investigational formulations of diphtheria, tetanus and Haemophilus influenzae type b antigens of the combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliomyelitis-Hib vaccine (DTPa-HBV-IPV/Hib) were evaluated in a Primary (NCT01248884) and a Booster vaccination (NCT01453998) study. In the Primary study, 721 healthy infants (randomized 1:1:1) received 3 doses of DTPa-HBV-IPV/Hib formulation A (DATAPa-HBV-IPV/Hib), or B (DBTBPa-HBV-IPV/Hib) or the licensed DTPa-HBV-IPV/Hib vaccine (Infanrix hexa, GSK; control group) at 2, 3, 4 months of age. Infants were planned to receive a booster dose at 12–15 months of age with the same formulation received in the Primary study; however, following high incidence of fever associated with the investigational formulations in the Primary study, the Booster study protocol was amended and all infants yet to receive a booster dose (N = 385) received the licensed vaccine. In the Primary study, non-inferiority of 3-dose vaccination with investigational formulations compared with the licensed vaccine was not demonstrated due to anti-pertactin failing to meet the non-inferiority criterion. Post-primary vaccination, most infants had seroprotective levels of anti-diphtheria (100% of infants), anti-tetanus antigens (100%), against hepatitis B (≥ 97.5% across groups), polyribosyl-ribitol-phosphate (≥ 88.0%) and poliovirus types 1–3 (≥ 90.5%). Seropositivity rates for each pertussis antigen were 100% in all groups. Higher incidence of fever (> 38°C) was reported in infants receiving the investigational formulations (Primary study: 75.0% [A] and 72.1% [B] vs 58.8% [control]; Booster study, before amendment: 49.4% and 46.6% vs 37.4%, respectively). The development of the investigational formulations was not further pursued. PMID:28340322

  7. Low dose radiation enhancing inhibitory effect of tumor-associated antigen peptide extract on H-22 hepatocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zuyue, Sun; Jingyi, Fu; Yong, Zhao [Transplantation Biology Research Division, State Key Laboratory of Biomembrane and Membrane Biotechnology, Inst. of Zoology, Chinese Academy of Sciences, Beijing (China); Jianxiang, Liu; Zhibo, Fu; Xiuyi, Li; Shuzheng, Liu; Shouliang, Gong

    2005-06-15

    Objective: To determine whether there is synergically inhibitory effect of low dose radiation (LDR) and tumor-associated antigen peptides (TAP) on tumor growth in vivo, which may provide experimental basis for potential clinical co-application of these two approaches to treat cancers. Methods: TAP extract (MW {<=}3x10{sup 6}) from tumor cell membrane was prepared with mild acid elution method , as reported. The mice were whole-bodily irradiated with 75 mGy X-rays 12 h before immunization with TAP extract. After immunization , the levels of CD3, CD69, TCR{alpha}{beta} cells and T cell subsets in the spleen were detected with FACS. The tumor growth rate was estimated, and the responses to Con A, the cytokine productions and CTL activities of splenocytes were also analyzed 7 d after immunization with TAP. Results: The present experimental results showed that the TAP extract significantly reduced the incidence of the transplanted tumor, delayed the average appearing time and decreased the growth speed of the tumor. The response of splenocytes from mice immunized with TAP extract to Con A increased significantly compared with that in the control group. Irradiation with 75 mGy X-rays 12 h before immunization further enhanced the inhibitory effect of TAP extract on tumor growth, and increased the percentage of CD8{sup +} splenocytes. Conclusion: These results suggest that whole-body irradiation with LDR exerts a synergic inhibitory effect with TAP on tumor growth in vivo, in which enhanced cellular immune responses may be involved. (authors)

  8. Breadth of T cell responses after immunization with adenovirus vectors encoding ancestral antigens or polyvalent papillomavirus antigens

    DEFF Research Database (Denmark)

    Ragonnaud, Emeline; Pedersen, Anders Gorm; Holst, Peter Johannes

    2017-01-01

    to the other PV proteins. The PV sequences were fused to a T cell adjuvant, the murine invariant chain and encoded in a recombinant adenoviral vector which was administered to naïve outbred mice. By measuring T cell responses induced by these different vaccines and towards peptide pools representing 3...... circulating strains and a putative ancestor of oncogenic HPVs, we showed that the ancestral vaccine antigen has to be approximately 90% identical to the circulating PVs before a marked drop of ~90% mean CD8+ T cell responses ensues. Interestingly, the combination of two or three type-specific PV vaccines did...

  9. Vaccination with p53-peptide-pulsed dendritic cells, of patients with advanced breast cancer: report from a phase I study

    DEFF Research Database (Denmark)

    Svane, Inge Marie; Pedersen, Anders E; Johnsen, Hans E

    2004-01-01

    the treatment. In conclusion, the strategy for p53-DC vaccination seems safe and without toxicity. Furthermore, indications of both immunologic and clinical effect were found in heavily pretreated patients with advanced breast cancer. An independent clinical effect of repeated administration of DCs and IL-2 can......Peptides derived from over-expressed p53 protein are presented by class I MHC molecules and may act as tumour-associated epitopes. Due to the diversity of p53 mutations, immunogenic peptides representing wild-type sequences are preferable as a basis for a broad-spectrum p53-targeting cancer vaccine......) loaded with a cocktail of three wild-type and three modified p53 peptides are being analysed in six HLA-A2+ patients with progressive advanced breast cancer. Vaccinations were well tolerated and no toxicity was observed. Disease stabilisation was seen in two of six patients, one patient had a transient...

  10. Novel 6xHis tagged foot-and-mouth disease virus vaccine bound to nanolipoprotein adjuvant via metal ions provides antigenic distinction and effective protective immunity

    International Nuclear Information System (INIS)

    Rai, Devendra K.; Segundo, Fayna Diaz-San; Schafer, Elizabeth; Burrage, Thomas G.; Rodriguez, Luis L.; Santos, Teresa de los; Hoeprich, Paul D.; Rieder, Elizabeth

    2016-01-01

    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. - Highlights: • 6xHis-tags in A_2_4 FMDV enable purification and biding to adjuvants via metal ions. • 6xHis A_2_4 FMDV:MPLA:NiNLP vaccine enhanced protective immunity against FMDV. • Surface exposed capsid tags allow distinction of infected from vaccinated animals.

  11. Novel 6xHis tagged foot-and-mouth disease virus vaccine bound to nanolipoprotein adjuvant via metal ions provides antigenic distinction and effective protective immunity

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Devendra K.; Segundo, Fayna Diaz-San [Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944 (United States); Department of Pathobiology and Veterinary Science, CANR, University of Connecticut, Storrs, CT 06269 (United States); Schafer, Elizabeth [Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944 (United States); Burrage, Thomas G. [Department of Homeland Security, S & T, Targeted Advance Development, Virus, Cellular and Molecular Imaging Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944 (United States); Rodriguez, Luis L.; Santos, Teresa de los [Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944 (United States); Hoeprich, Paul D. [Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA (United States); Rieder, Elizabeth, E-mail: Elizabeth.Rieder@ars.usda.gov [Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944 (United States)

    2016-08-15

    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{sup 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{sup 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. - Highlights: • 6xHis-tags in A{sub 24} FMDV enable purification and biding to adjuvants via metal ions. • 6xHis A{sub 24} FMDV:MPLA:NiNLP vaccine enhanced protective immunity against FMDV. • Surface exposed capsid tags allow distinction of infected from vaccinated animals.

  12. Naive helper T cells from BCG-vaccinated volunteers produce IFN-gamma and IL-5 to mycobacterial antigen-pulsed dendritic cells.

    Directory of Open Access Journals (Sweden)

    JoĂŤl Pestel

    2008-06-01

    Full Text Available Mycobacterium bovis bacillus Calmette-GuĂŠrin (BCG is a live vaccine that has been used in routine vaccination against tuberculosis for nearly 80 years. However, its efficacy is controversial. The failure of BCG vaccination may be at least partially explained by the induction of poor or inappropriate host responses. Dendritic cells (DCs are likely to play a key role in the induction of immune response to mycobacteria by polarizing the reactivity of T lymphocytes toward a Th1 profile, contributing to the generation of protective cellular immunity against mycobacteria. In this study we aimed to investigate the production of Th1 and Th2 cytokines by naive CD4+ T cells to mycobacterial antigen-pulsed DCs in the group of young, healthy BCG vaccinated volunteers. The response of naive helper T cells was compared with the response of total blood lymphocytes. Our present results clearly showed that circulating naive CD45RA+CD4+ lymphocytes from BCG-vaccinated subjects can become effector helper cells producing IFN-gamma and IL-5 under the stimulation by autologous dendritic cells presenting mycobacterial protein antigen-PPD or infected with live M. bovis BCG bacilli.

  13. Naive helper T cells from BCG-vaccinated volunteers produce IFN-gamma and IL-5 to mycobacterial antigen-pulsed dendritic cells.

    Science.gov (United States)

    Kowalewicz-Kulbat, Magdalena; Kaźmierczak, Dominik; Donevski, Stefan; Biet, Franck; Pestel, Joël; Rudnicka, Wiesława

    2008-01-01

    Mycobacterium bovis bacillus Calmette-Guérin (BCG) is a live vaccine that has been used in routine vaccination against tuberculosis for nearly 80 years. However, its efficacy is controversial. The failure of BCG vaccination may be at least partially explained by the induction of poor or inappropriate host responses. Dendritic cells (DCs) are likely to play a key role in the induction of immune response to mycobacteria by polarizing the reactivity of T lymphocytes toward a Th1 profile, contributing to the generation of protective cellular immunity against mycobacteria. In this study we aimed to investigate the production of Th1 and Th2 cytokines by naive CD4+ T cells to mycobacterial antigen-pulsed DCs in the group of young, healthy BCG vaccinated volunteers. The response of naive helper T cells was compared with the response of total blood lymphocytes. Our present results clearly showed that circulating naive CD45RA+CD4+ lymphocytes from BCG-vaccinated subjects can become effector helper cells producing IFN-gamma and IL-5 under the stimulation by autologous dendritic cells presenting mycobacterial protein antigen-PPD or infected with live M. bovis BCG bacilli.

  14. GapA, a potential vaccine candidate antigen against Streptococcus agalactiae in Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Zhang, Ze; Yu, Angen; Lan, Jiangfeng; Zhang, Hua; Hu, Minqiang; Cheng, Jiewei; Zhao, Lijuan; Lin, Li; Wei, Shun

    2017-04-01

    Streptococcosis due to the bacterium Streptococcus agalactiae (S. agalactiae) has resulted in enormous economic losses in aquaculture worldwide, especially in the tilapia culture industry. Previously, there were limited vaccines that could be employed against streptococcosis in tilapia. This study aimed to develop a vaccine candidate using the glyceraldehyde-phosphate dehydrogenase protein (GapA) of S. agalactiae encoded by the gapA gene. Tilapia were intraperitoneally injected with PBS, PBS + Freund's adjuvant, PBS + Montanide's adjuvant, GapA + Freund's adjuvant, GapA + Montanide's adjuvant, killed S. agalactiae whole cells (WC)+Freund's adjuvant, or killed S. agalactiae whole cells (WC)+ Montanide's adjuvant. They were then challenged with S. agalactiae, and the relative percentage survival (RPS) was monitored 14 days after the challenge. The highest RPSs were observed in the WC groups, with 76.7% in WC + Freund's adjuvant and 74.4% in WC + Montanide's adjuvant groups; these were followed by the GapA groups, with 63.3% in GapA + Freund's adjuvant and 45.6% in GapA + Montanide's adjuvant groups. The RPS of the PBS group was 0%, and those of PBS + Freund's adjuvant and PBS + Montanide's adjuvant groups were 6.7% and 3.3%, respectively. Additionally, the IgM antibody responses elicited in GapA groups and WC groups were significantly higher than those in PBS groups. Furthermore, the expressions of cytokine (IL-1β and TNF-α) mRNAs in the GapA groups and WC groups were significantly higher than those in the PBS groups. Taken together, these results reveal that the GapA protein is a promising vaccine candidate that could be used to prevent streptococcosis in tilapia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Now and future influenza vaccines.

    Science.gov (United States)

    Ruben, F L

    1990-03-01

    Influenza is a modern day plague. In the young, the clinical picture is classical, but in the elderly, the disease may go unsuspected until complications such as pneumonia develop. Influenza A and B viruses are responsible, and these viruses mutate with great regularity. Antibodies to the HA and NA surface antigens of influenza viruses, both naturally and vaccine induced, are protective. The earliest influenza vaccines were crude, toxic, and ineffective. With modern purification techniques, the egg-grown viruses have been turned into safe, immunogenic, and effective killed-virus vaccines--whole virus and split virus. Surveillance permits the correct virus strains to be incorporated into each new vaccine. Those who have been experiencing the worst effects of influenza have been identified. These individuals need to be immunized each year. In the future, live influenza virus vaccines may offer the benefits of ease of administration and longer-lasting protection. Synthetic peptides, genetically engineered antigens, and even nonantigen (anti-idiotype) vaccines are possible, but such vaccines will require adjuvant enhancement. For the present, greater efforts must be made to use existing influenza vaccines.

  17. Blocking herpes simplex virus 2 glycoprotein E immune evasion as an approach to enhance efficacy of a trivalent subunit antigen vaccine for genital herpes.

    Science.gov (United States)

    Awasthi, Sita; Huang, Jialing; Shaw, Carolyn; Friedman, Harvey M

    2014-08-01

    Herpes simplex virus 2 (HSV-2) subunit antigen vaccines targeting virus entry molecules have failed to prevent genital herpes in human trials. Our approach is to include a virus entry molecule and add antigens that block HSV-2 immune evasion. HSV-2 glycoprotein C (gC2) is an immune evasion molecule that inhibits complement. We previously reported that adding gC2 to gD2 improved vaccine efficacy compared to the efficacy of either antigen alone in mice and guinea pigs. Here we demonstrate that HSV-2 glycoprotein E (gE2) functions as an immune evasion molecule by binding the IgG Fc domain. HSV-2 gE2 is synergistic with gC2 in protecting the virus from antibody and complement neutralization. Antibodies produced by immunization with gE2 blocked gE2-mediated IgG Fc binding and cell-to-cell spread. Mice immunized with gE2 were only partially protected against HSV-2 vaginal challenge in mice; however, when gE2 was added to gC2/gD2 to form a trivalent vaccine, neutralizing antibody titers with and without complement were significantly higher than those produced by gD2 alone. Importantly, the trivalent vaccine protected the dorsal root ganglia (DRG) of 32/33 (97%) mice between days 2 and 7 postchallenge, compared with 27/33 (82%) in the gD2 group. The HSV-2 DNA copy number was significantly lower in mice immunized with the trivalent vaccine than in those immunized with gD2 alone. The extent of DRG protection using the trivalent vaccine was better than what we previously reported for gC2/gD2 immunization. Therefore, gE2 is a candidate antigen for inclusion in a multivalent subunit vaccine that attempts to block HSV-2 immune evasion. Herpes simplex virus is the most common cause of genital ulcer disease worldwide. Infection results in emotional distress for infected individuals and their partners, is life threatening for infants exposed to herpes during childbirth, and greatly increases the risk of individuals acquiring and transmitting HIV infection. A vaccine that prevents

  18. Antigen localization and the induction of resistance in mice vaccinated with irradiated cercariae of Schistosoma mansoni

    International Nuclear Information System (INIS)

    Mountford, A.P.; Coulson, P.S.; Wilson, R.A.

    1988-01-01

    The fate of 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. (author)

  19. 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 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.

  20. Characterization of a single peptide derived from cytochrome P4501B1 that elicits spontaneous human leukocyte antigen (HLA)-A1 as well as HLA-B35 restricted CD8 T-cell responses in cancer patients

    DEFF Research Database (Denmark)

    Kvistborg, P.; Hadrup, S.R.; Andersen, M.H.

    2008-01-01

    presenting the peptide on the surface. The characterized CYP240 peptide presented herein opens the avenue for more broader recruitment of patients in vaccination trials targeting CYB1B1. (C) 2008 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved......, targeting of CYP1B1 represents a potentially successful strategy in the treatment of metastatic cancer, e.g., by therapeutic vaccination. Herein, we describe the characterization of a novel peptide from the CYP1B1 protein (CYP240), which is spontaneously recognized by CD8 T cells in cancer patients...

  1. Promiscuous survivin peptide induces robust CD4+ T-cell responses in the majority of vaccinated cancer patients.

    Science.gov (United States)

    Widenmeyer, Melanie; Griesemann, Heinrich; Stevanović, Stefan; Feyerabend, Susan; Klein, Reinhild; Attig, Sebastian; Hennenlotter, Jörg; Wernet, Dorothee; Kuprash, Dmitri V; Sazykin, Alexei Y; Pascolo, Steve; Stenzl, Arnulf; Gouttefangeas, Cécile; Rammensee, Hans-Georg

    2012-07-01

    CD4(+) T cells have been shown to be crucial for the induction and maintenance of cytotoxic T cell responses and to be also capable of mediating direct tumor rejection. Therefore, the anticancer therapeutic efficacy of peptide-based vaccines may be improved by addition of HLA class II epitopes to stimulate T helper cells. Survivin is an apoptosis inhibiting protein frequently overexpressed in tumors. Here we describe the first immunological evaluation of a survivin-derived CD4(+) T cell epitope in a multipeptide immunotherapy trial for prostate carcinoma patients. The survivin peptide is promiscuously presented by several human HLA-DRB1 molecules and, most importantly, is naturally processed by dendritic cells. In vaccinated patients, it was able to induce frequent, robust and multifunctional CD4(+) T cell responses, as monitored by IFN-γ ELISPOT and intracellular cytokine staining. Thus, this HLA-DR restricted epitope is broadly immunogenic and should be valuable for stimulating T helper cells in patients suffering from a wide range of tumors. Copyright © 2011 UICC.

  2. CD4+ T-cell lines used to evaluate a Mycobacterium avium subsp. paratuberculosis (MAP) peptide vaccine

    DEFF Research Database (Denmark)

    Lybeck, Kari; Sjurseth, Siri K.; Al-Touama, Zainab