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Sample records for antigen targeted immune

  1. Immunity to tumour antigens.

    Science.gov (United States)

    Li, Geng; Ali, Selman A; McArdle, Stephanie E B; Mian, Shahid; Ahmad, Murrium; Miles, Amanda; Rees, Robert C

    2005-01-01

    During the last decade, a large number of human tumour antigens have been identified. These antigens are classified as tumour-specific shared antigens, tissue-specific differentiation antigens, overexpressed antigens, tumour antigens resulting from mutations, viral antigens and fusion proteins. Antigens recognised by effectors of immune system are potential targets for antigen-specific cancer immunotherapy. However, most tumour antigens are self-proteins and are generally of low immunogenicity and the immune response elicited towards these tumour antigens is not always effective. Strategies to induce and enhance the tumour antigen-specific response are needed. This review will summarise the approaches to discovery of tumour antigens, the current status of tumour antigens, and their potential application to cancer treatment.

  2. 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.

  3. Antigen Cross-Presentation of Immune Complexes

    Science.gov (United States)

    Platzer, Barbara; Stout, Madeleine; Fiebiger, Edda

    2014-01-01

    The ability of dendritic cells (DCs) to cross-present tumor antigens has long been a focus of interest to physicians, as well as basic scientists, that aim to establish efficient cell-based cancer immune therapy. A prerequisite for exploiting this pathway for therapeutic purposes is a better understanding of the mechanisms that underlie the induction of tumor-specific cytotoxic T-lymphocyte (CTL) responses when initiated by DCs via cross-presentation. The ability of humans DC to perform cross-presentation is of utmost interest, as this cell type is a main target for cell-based immunotherapy in humans. The outcome of a cross-presentation event is guided by the nature of the antigen, the form of antigen uptake, and the subpopulation of DCs that performs presentation. Generally, CD8α+ DCs are considered to be the most potent cross-presenting DCs. This paradigm, however, only applies to soluble antigens. During adaptive immune responses, immune complexes form when antibodies interact with their specific epitopes on soluble antigens. Immunoglobulin G (IgG) immune complexes target Fc-gamma receptors on DCs to shuttle exogenous antigens efficiently into the cross-presentation pathway. This receptor-mediated cross-presentation pathway is a well-described route for the induction of strong CD8+ T cell responses. IgG-mediated cross-presentation is intriguing because it permits the CD8− DCs, which are commonly considered to be weak cross-presenters, to efficiently cross-present. Engaging multiple DC subtypes for cross-presentation might be a superior strategy to boost CTL responses in vivo. We here summarize our current understanding of how DCs use IgG-complexed antigens for the efficient induction of CTL responses. Because of its importance for human cell therapy, we also review the recent advances in the characterization of cross-presentation properties of human DC subsets. PMID:24744762

  4. Antigen detection in vivo after immunization with different presentation forms of rabies virus antigen: Involvement of marginal metallophilic macrophages in the uptake of immune-stimulating complexes

    NARCIS (Netherlands)

    Claassen, I.J.T.M.; Osterhaus, A.D.M.E.; Claassen, E.

    1995-01-01

    Several mechanisms have been postulated to explain the relatively high immunogenicity of antigens presented in immune-stimulating complexes (iscom). Their potency can in part be explained by the specific targeting of these structures to cells presenting antigens to the immune system. However, until

  5. Antigen detection in vivo after immunization with different presentation forms of rabies virus antigen: involvement of marginal metallophilic macrophages in the uptake of immune-stimulating complexes.

    NARCIS (Netherlands)

    I.J.Th.M. Claassen (Ivo); A.D.M.E. Osterhaus (Albert); H.J.H.M. Claassen (Eric)

    1995-01-01

    textabstractSeveral mechanisms have been postulated to explain the relatively high immunogenicity of antigens presented in immune-stimulating complexes (iscom). Their potency can in part be explained by the specific targeting of these structures to cells presenting antigens to the immune system.

  6. Applying Convergent Immunity to Innovative Vaccines Targeting Staphylococcus aureus

    Science.gov (United States)

    Yeaman, Michael R.; Filler, Scott G.; Schmidt, Clint S.; Ibrahim, Ashraf S.; Edwards, John E.; Hennessey, John P.

    2014-01-01

    Recent perspectives forecast a new paradigm for future “third generation” vaccines based on commonalities found in diverse pathogens or convergent immune defenses to such pathogens. For Staphylococcus aureus, recurring infections and a limited success of vaccines containing S. aureus antigens imply that native antigens induce immune responses insufficient for optimal efficacy. These perspectives exemplify the need to apply novel vaccine strategies to high-priority pathogens. One such approach can be termed convergent immunity, where antigens from non-target organisms that contain epitope homologs found in the target organism are applied in vaccines. This approach aims to evoke atypical immune defenses via synergistic processes that (1) afford protective efficacy; (2) target an epitope from one organism that contributes to protective immunity against another; (3) cross-protect against multiple pathogens occupying a common anatomic or immunological niche; and/or (4) overcome immune subversion or avoidance strategies of target pathogens. Thus, convergent immunity has a potential to promote protective efficacy not usually elicited by native antigens from a target pathogen. Variations of this concept have been mainstays in the history of viral and bacterial vaccine development. A more far-reaching example is the pre-clinical evidence that specific fungal antigens can induce cross-kingdom protection against bacterial pathogens. This trans-kingdom protection has been demonstrated in pre-clinical studies of the recombinant Candida albicans agglutinin-like sequence 3 protein (rAls3) where it was shown that a vaccine containing rAls3 provides homologous protection against C. albicans, heterologous protection against several other Candida species, and convergent protection against several strains of S. aureus. Convergent immunity reflects an intriguing new approach to designing and developing vaccine antigens and is considered here in the context of vaccines to target S

  7. Applying Convergent Immunity to Innovative Vaccines Targeting Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Michael R Yeaman

    2014-09-01

    Full Text Available Recent perspectives forecast a new paradigm for future 3rd generation vaccines based on commonalities found in diverse pathogens or convergent immune defenses to such pathogens. For Staphylococcus aureus, recurring infections and a limited success of vaccines containing S. aureus antigens imply that native antigens induce immune responses insufficient for optimal efficacy. These perspectives exemplify the need to apply novel vaccine strategies to high priority pathogens. One such approach can be termed convergent immunity, where antigens from non-target organisms that contain epitope homologues found in the target organism are applied in vaccines. This approach aims to evoke atypical immune defenses via synergistic processes that 1 afford protective efficacy; 2 target an epitope from one organism that contributes to protective immunity against another; 3 cross-protect against multiple pathogens occupying a common anatomic or immunologic niche; and/or 4 overcome immune subversion or avoidance strategies of target pathogens. Thus, convergent immunity has a potential to promote protective efficacy not usually elicited by native antigens from a target pathogen. Variations of this concept have been mainstays in the history of viral and bacterial vaccine development. A more far-reaching example is the pre–clinical evidence that specific fungal antigens can induce cross-kingdom protection against bacterial pathogens. This trans-kingdom protection has been demonstrated in preclinical studies of the recombinant Candida albicans agglutinin-like sequence 3 protein (rAls3 where it was shown that a vaccine containing rAls3 provides homologous protection against C. albicans, heterologous protection against several other Candida species, and convergent protection against several strains of S. aureus. Convergent immunity reflects an intriguing new approach to designing and developing vaccine antigens and is considered here in the context of vaccines to target

  8. Targeting tumor antigens to secreted membrane vesicles in vivo induces efficient antitumor immune responses.

    Science.gov (United States)

    Zeelenberg, Ingrid S; Ostrowski, Matias; Krumeich, Sophie; Bobrie, Angélique; Jancic, Carolina; Boissonnas, Alexandre; Delcayre, Alain; Le Pecq, Jean-Bernard; Combadière, Béhazine; Amigorena, Sebastian; Théry, Clotilde

    2008-02-15

    Expression of non-self antigens by tumors can induce activation of T cells in vivo, although this activation can lead to either immunity or tolerance. CD8+ T-cell activation can be direct (if the tumor expresses MHC class I molecules) or indirect (after the capture and cross-presentation of tumor antigens by dendritic cells). The modes of tumor antigen capture by dendritic cells in vivo remain unclear. Here we examine the immunogenicity of the same model antigen secreted by live tumors either in association with membrane vesicles (exosomes) or as a soluble protein. We have artificially addressed the antigen to secreted vesicles by coupling it to the factor VIII-like C1C2 domain of milk fat globule epidermal growth factor-factor VIII (MFG-E8)/lactadherin. We show that murine fibrosarcoma tumor cells that secrete vesicle-bound antigen grow slower than tumors that secrete soluble antigen in immunocompetent, but not in immunodeficient, host mice. This growth difference is due to the induction of a more potent antigen-specific antitumor immune response in vivo by the vesicle-bound than by the soluble antigen. Finally, in vivo secretion of the vesicle-bound antigen either by tumors or by vaccination with naked DNA protects against soluble antigen-secreting tumors. We conclude that the mode of secretion can determine the immunogenicity of tumor antigens and that manipulation of the mode of antigen secretion may be used to optimize antitumor vaccination protocols.

  9. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity.

    Directory of Open Access Journals (Sweden)

    Martin Kreutz

    Full Text Available Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is paramount. However, co-administration of unlinked adjuvant cannot ensure that all cells targeted by the antibody conjugates are appropriately activated. Furthermore, antigen-presenting cells (APC that do not present the desired antigen are equally strongly activated and could prime undesired responses against self-antigens. We, therefore, were interested in exploring targeted co-delivery of antigen and adjuvant in cis in form of antibody-antigen-adjuvant conjugates for the induction of anti-tumour immunity. In this study, we report on the assembly and characterization of conjugates consisting of DEC205-specific antibody, the model antigen ovalbumin (OVA and CpG oligodeoxynucleotides (ODN. We show that such conjugates are more potent at inducing cytotoxic T lymphocyte (CTL responses than control conjugates mixed with soluble CpG. However, our study also reveals that the nucleic acid moiety of such antibody-antigen-adjuvant conjugates alters their binding and uptake and allows delivery of the antigen and the adjuvant to cells partially independently of DEC205. Nevertheless, antibody-antigen-adjuvant conjugates are superior to antibody-free antigen-adjuvant conjugates in priming CTL responses and efficiently induce anti-tumour immunity in the murine B16 pseudo-metastasis model. A better understanding of the role of the antibody moiety is required to inform future conjugate vaccination strategies for efficient induction of anti-tumour responses.

  10. Targeted delivery of antigen to intestinal dendritic cells induces oral tolerance and prevents autoimmune diabetes in NOD mice.

    Science.gov (United States)

    Chen, Yulin; Wu, Jie; Wang, Jiajia; Zhang, Wenjing; Xu, Bohui; Xu, Xiaojun; Zong, Li

    2018-03-15

    The intestinal immune system is an ideal target to induce immune tolerance physiologically. However, the efficiency of oral protein antigen delivery is limited by degradation of the antigen in the gastrointestinal tract and poor uptake by antigen-presenting cells. Gut dendritic cells (DCs) are professional antigen-presenting cells that are prone to inducing antigen-specific immune tolerance. In this study, we delivered the antigen heat shock protein 65-6×P277 (H6P) directly to the gut DCs of NOD mice through oral vaccination with H6P-loaded targeting nanoparticles (NPs), and investigated the ability of this antigen to induce immune tolerance to prevent autoimmune diabetes in NOD mice. A targeting NP delivery system was developed to encapsulate H6P, and the ability of this system to protect and facilitate H6P delivery to gut DCs was assessed. NOD mice were immunised with H6P-loaded targeting NPs orally once a week for 7 weeks and the onset of diabetes was assessed by monitoring blood glucose levels. H6P-loaded targeting NPs protected the encapsulated H6P from degradation in the gastrointestinal tract environment and significantly increased the uptake of H6P by DCs in the gut Peyer's patches (4.1 times higher uptake compared with the control H6P solution group). Oral vaccination with H6P-loaded targeting NPs induced antigen-specific T cell tolerance and prevented diabetes in 100% of NOD mice. Immune deviation (T helper [Th]1 to Th2) and CD4 + CD25 + FOXP3 + regulatory T cells were found to participate in the induction of immune tolerance. In this study, we successfully induced antigen-specific T cell tolerance and prevented the onset of diabetes in NOD mice. To our knowledge, this is the first attempt at delivering antigen to gut DCs using targeting NPs to induce T cell tolerance.

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

    Directory of Open Access Journals (Sweden)

    Cleo Goyvaerts

    2015-01-01

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

  12. Non-MHC Antigenic Targets of the Humoral Immune Response in Transplantation

    OpenAIRE

    Zhang, Qiuheng; Reed, Elaine F.

    2010-01-01

    There is a growing body of data supporting a role for non-HLA antibodies in acute and chronic rejection of solid organ transplants. While many of these non-HLA antigens remain poorly defined, the principle antigenic targets are expressed on cells of the allograft including endothelium and epithelium. These non-HLA antigens are classified as either alloantigens, such as the major histocompatibility complex class I chain-related gene A (MICA) or MICB, or tissue-specific autoantigens such as vim...

  13. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity

    NARCIS (Netherlands)

    Kreutz, M.; Giquel, B.; Hu, Q.; Abuknesha, R.; Uematsu, S.; Akira, S.; Nestle, F.O.; Diebold, S.S.

    2012-01-01

    Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC) by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is

  14. 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.

  15. Immunizations with hepatitis B viral antigens and a TLR7/8 agonist adjuvant induce antigen-specific immune responses in HBV-transgenic mice

    Directory of Open Access Journals (Sweden)

    Ying Wang

    2014-12-01

    Conclusions: Immunization with CL097-conjugated HBV-Ag reversed immune tolerance in HBV-Tg mice and induced antigen-specific immune responses. TLR7/8 agonists appear to be potent adjuvants for the induction of antigen-specific Th1 responses in an immune tolerant state.

  16. T cells targeting a neuronal paraneoplastic antigen mediate tumor rejection and trigger CNS autoimmunity with humoral activation.

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    Blachère, Nathalie E; Orange, Dana E; Santomasso, Bianca D; Doerner, Jessica; Foo, Patricia K; Herre, Margaret; Fak, John; Monette, Sébastien; Gantman, Emily C; Frank, Mayu O; Darnell, Robert B

    2014-11-01

    Paraneoplastic neurologic diseases (PND) involving immune responses directed toward intracellular antigens are poorly understood. Here, we examine immunity to the PND antigen Nova2, which is expressed exclusively in central nervous system (CNS) neurons. We hypothesized that ectopic expression of neuronal antigen in the periphery could incite PND. In our C57BL/6 mouse model, CNS antigen expression limits antigen-specific CD4+ and CD8+ T-cell expansion. Chimera experiments demonstrate that this tolerance is mediated by antigen expression in nonhematopoietic cells. CNS antigen expression does not limit tumor rejection by adoptively transferred transgenic T cells but does limit the generation of a memory population that can be expanded upon secondary challenge in vivo. Despite mediating cancer rejection, adoptively transferred transgenic T cells do not lead to paraneoplastic neuronal targeting. Preliminary experiments suggest an additional requirement for humoral activation to induce CNS autoimmunity. This work provides evidence that the requirements for cancer immunity and neuronal autoimmunity are uncoupled. Since humoral immunity was not required for tumor rejection, B-cell targeting therapy, such as rituximab, may be a rational treatment option for PND that does not hamper tumor immunity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. CELLISA: reporter cell-based immunization and screening of hybridomas specific for cell surface antigens.

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    Chen, Peter; Mesci, Aruz; Carlyle, James R

    2011-01-01

    Monoclonal antibodies (mAbs) specific for cell surface antigens are an invaluable tool to study immune receptor expression and function. Here, we outline a generalized reporter cell-based approach to the generation and high-throughput screening of mAbs specific for cell surface antigens. Termed CELLISA, this technology hinges upon the capture of hybridoma supernatants in mAb arrays that facilitate ligation of an antigen of interest displayed on BWZ reporter cells in the form of a CD3ζ-fusion chimeric antigen receptor (zCAR); in turn, specific mAb-mediated cross-linking of zCAR on BWZ cells results in the production of β-galactosidase enzyme (β-gal), which can be assayed colorimetrically. Importantly, the BWZ reporter cells bearing the zCAR of interest may be used for immunization as well as screening. In addition, serial immunizations employing additional zCAR- or native antigen-bearing cell lines can be used to increase the frequency of the desired antigen-specific hybridomas. Finally, the use of a cohort of epitope-tagged zCAR (e.g., zCAR(FLAG)) variants allows visualization of the cell surface antigen prior to immunization, and coimmunization using these variants can be used to enhance the immunogenicity of the target antigen. Employing the CELLISA strategy, we herein describe the generation of mAb directed against an uncharacterized natural killer cell receptor protein.

  18. Targeted Delivery of GP5 Antigen of PRRSV to M Cells Enhances the Antigen-Specific Systemic and Mucosal Immune Responses

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    Luping Du

    2018-01-01

    Full Text Available Efficient delivery of antigens through oral immunization is a first and critical step for successful induction of mucosal immunity, which can provide protection against pathogens invading the mucosa. Membranous/microfold cells (M cells within the mucosa can transcytose internalized antigen without degradation and thus play an important role in initiating antigen-specific mucosal immune responses through inducing secretory IgA production. In this research, we modified poly (D, L-lactide-co-glycolide (PLGA nanoparticles (NPs with Ulex europaeus agglutinin 1 (UEA-1 and successfully prepared an oral vaccine delivery system, UEA-1/PLGA NPs. PLGA NPs were prepared using a standard double emulsion solvent evaporation technique, which can protect the entrapped PRRSV DNA vaccine [pcDNA3.1-SynORF5 (synthetic ORF5] or subunit vaccine ORF5-encoded glycoprotein (GP5 from exposure to the gastrointestinal (GI tract and release the plasmids in a controlled manner. With UEA-1 modification, the UEA-1/PLGA NPs can be effectively transported by M-cells. We investigated immune response induced by UEA-1/PLGA-SynORF5 or UEA-1/PLGA-GP5 following inoculation in mice and piglets. Compared with PLGA-SynORF5 or PLGA-GP5 NPs, UEA-1/PLGA-SynORF5, or UEA-1/PLGA-GP5 NPs stimulated significantly increased serum IgG levels and augmented intestinal IgA levels in mice and piglets (P < 0.05. Our findings indicate UEA-1/PLGA NPs can be applied as a promising and universally robust oral vaccine delivery system.

  19. Targeted Delivery of GP5 Antigen of PRRSV to M Cells Enhances the Antigen-Specific Systemic and Mucosal Immune Responses

    Science.gov (United States)

    Du, Luping; Yu, Zhengyu; Pang, Fengjiao; Xu, Xiangwei; Mao, Aihua; Yuan, Wanzhe; He, Kongwang; Li, Bin

    2018-01-01

    Efficient delivery of antigens through oral immunization is a first and critical step for successful induction of mucosal immunity, which can provide protection against pathogens invading the mucosa. Membranous/microfold cells (M cells) within the mucosa can transcytose internalized antigen without degradation and thus play an important role in initiating antigen-specific mucosal immune responses through inducing secretory IgA production. In this research, we modified poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) with Ulex europaeus agglutinin 1 (UEA-1) and successfully prepared an oral vaccine delivery system, UEA-1/PLGA NPs. PLGA NPs were prepared using a standard double emulsion solvent evaporation technique, which can protect the entrapped PRRSV DNA vaccine [pcDNA3.1-SynORF5 (synthetic ORF5)] or subunit vaccine ORF5-encoded glycoprotein (GP5) from exposure to the gastrointestinal (GI) tract and release the plasmids in a controlled manner. With UEA-1 modification, the UEA-1/PLGA NPs can be effectively transported by M-cells. We investigated immune response induced by UEA-1/PLGA-SynORF5 or UEA-1/PLGA-GP5 following inoculation in mice and piglets. Compared with PLGA-SynORF5 or PLGA-GP5 NPs, UEA-1/PLGA-SynORF5, or UEA-1/PLGA-GP5 NPs stimulated significantly increased serum IgG levels and augmented intestinal IgA levels in mice and piglets (P < 0.05). Our findings indicate UEA-1/PLGA NPs can be applied as a promising and universally robust oral vaccine delivery system. PMID:29423381

  20. Enhancement of the priming efficacy of DNA vaccines encoding dendritic cell-targeted antigens by synergistic toll-like receptor ligands

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    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.

  1. Immunization against Rabies with Plant-Derived Antigen

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    Modelska, Anna; Dietzschold, Bernard; Sleysh, N.; Fu, Zhen Fang; Steplewski, Klaudia; Hooper, D. Craig; Koprowski, Hilary; Yusibov, Vidadi

    1998-03-01

    We previously demonstrated that recombinant plant virus particles containing a chimeric peptide representing two rabies virus epitopes stimulate virus neutralizing antibody synthesis in immunized mice. We show here that mice immunized intraperitoneally or orally (by gastric intubation or by feeding on virus-infected spinach leaves) with engineered plant virus particles containing rabies antigen mount a local and systemic immune response. After the third dose of antigen, given intraperitoneally, 40% of the mice were protected against challenge infection with a lethal dose of rabies virus. Oral administration of the antigen stimulated serum IgG and IgA synthesis and ameliorated the clinical signs caused by intranasal infection with an attenuated rabies virus strain.

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

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    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.

  3. Increasing vaccine potency through exosome antigen targeting.

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    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.

  4. Delivery of antigen to nasal-associated lymphoid tissue microfold cells through secretory IgA targeting local dendritic cells confers protective immunity.

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    Rochereau, Nicolas; Pavot, Vincent; Verrier, Bernard; Jospin, Fabienne; Ensinas, Agathe; Genin, Christian; Corthésy, Blaise; Paul, Stéphane

    2016-01-01

    Transmission of mucosal pathogens relies on their ability to bind to the surfaces of epithelial cells, to cross this thin barrier, and to gain access to target cells and tissues, leading to systemic infection. This implies that pathogen-specific immunity at mucosal sites is critical for the control of infectious agents using these routes to enter the body. Although mucosal delivery would ensure the best onset of protective immunity, most of the candidate vaccines are administered through the parenteral route. The present study evaluates the feasibility of delivering the chemically bound p24gag (referred to as p24 in the text) HIV antigen through secretory IgA (SIgA) in nasal mucosae in mice. We show that SIgA interacts specifically with mucosal microfold cells present in the nasal-associated lymphoid tissue. p24-SIgA complexes are quickly taken up in the nasal cavity and selectively engulfed by mucosal dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin-positive dendritic cells. Nasal immunization with p24-SIgA elicits both a strong humoral and cellular immune response against p24 at the systemic and mucosal levels. This ensures effective protection against intranasal challenge with recombinant vaccinia virus encoding p24. This study represents the first example that underscores the remarkable potential of SIgA to serve as a carrier for a protein antigen in a mucosal vaccine approach targeting the nasal environment. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  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. Immunization Elicits Antigen-Specific Antibody Sequestration in Dorsal Root Ganglia Sensory Neurons

    Science.gov (United States)

    Gunasekaran, Manojkumar; Chatterjee, Prodyot K.; Shih, Andrew; Imperato, Gavin H.; Addorisio, Meghan; Kumar, Gopal; Lee, Annette; Graf, John F.; Meyer, Dan; Marino, Michael; Puleo, Christopher; Ashe, Jeffrey; Cox, Maureen A.; Mak, Tak W.; Bouton, Chad; Sherry, Barbara; Diamond, Betty; Andersson, Ulf; Coleman, Thomas R.; Metz, Christine N.; Tracey, Kevin J.; Chavan, Sangeeta S.

    2018-01-01

    The immune and nervous systems are two major organ systems responsible for host defense and memory. Both systems achieve memory and learning that can be retained, retrieved, and utilized for decades. Here, we report the surprising discovery that peripheral sensory neurons of the dorsal root ganglia (DRGs) of immunized mice contain antigen-specific antibodies. Using a combination of rigorous molecular genetic analyses, transgenic mice, and adoptive transfer experiments, we demonstrate that DRGs do not synthesize these antigen-specific antibodies, but rather sequester primarily IgG1 subtype antibodies. As revealed by RNA-seq and targeted quantitative PCR (qPCR), dorsal root ganglion (DRG) sensory neurons harvested from either naïve or immunized mice lack enzymes (i.e., RAG1, RAG2, AID, or UNG) required for generating antibody diversity and, therefore, cannot make antibodies. Additionally, transgenic mice that express a reporter fluorescent protein under the control of Igγ1 constant region fail to express Ighg1 transcripts in DRG sensory neurons. Furthermore, neural sequestration of antibodies occurs in mice rendered deficient in neuronal Rag2, but antibody sequestration is not observed in DRG sensory neurons isolated from mice that lack mature B cells [e.g., Rag1 knock out (KO) or μMT mice]. Finally, adoptive transfer of Rag1-deficient bone marrow (BM) into wild-type (WT) mice or WT BM into Rag1 KO mice revealed that antibody sequestration was observed in DRG sensory neurons of chimeric mice with WT BM but not with Rag1-deficient BM. Together, these results indicate that DRG sensory neurons sequester and retain antigen-specific antibodies released by antibody-secreting plasma cells. Coupling this work with previous studies implicating DRG sensory neurons in regulating antigen trafficking during immunization raises the interesting possibility that the nervous system collaborates with the immune system to regulate antigen-mediated responses. PMID:29755449

  7. Immunization Elicits Antigen-Specific Antibody Sequestration in Dorsal Root Ganglia Sensory Neurons

    Directory of Open Access Journals (Sweden)

    Manojkumar Gunasekaran

    2018-04-01

    Full Text Available The immune and nervous systems are two major organ systems responsible for host defense and memory. Both systems achieve memory and learning that can be retained, retrieved, and utilized for decades. Here, we report the surprising discovery that peripheral sensory neurons of the dorsal root ganglia (DRGs of immunized mice contain antigen-specific antibodies. Using a combination of rigorous molecular genetic analyses, transgenic mice, and adoptive transfer experiments, we demonstrate that DRGs do not synthesize these antigen-specific antibodies, but rather sequester primarily IgG1 subtype antibodies. As revealed by RNA-seq and targeted quantitative PCR (qPCR, dorsal root ganglion (DRG sensory neurons harvested from either naïve or immunized mice lack enzymes (i.e., RAG1, RAG2, AID, or UNG required for generating antibody diversity and, therefore, cannot make antibodies. Additionally, transgenic mice that express a reporter fluorescent protein under the control of Igγ1 constant region fail to express Ighg1 transcripts in DRG sensory neurons. Furthermore, neural sequestration of antibodies occurs in mice rendered deficient in neuronal Rag2, but antibody sequestration is not observed in DRG sensory neurons isolated from mice that lack mature B cells [e.g., Rag1 knock out (KO or μMT mice]. Finally, adoptive transfer of Rag1-deficient bone marrow (BM into wild-type (WT mice or WT BM into Rag1 KO mice revealed that antibody sequestration was observed in DRG sensory neurons of chimeric mice with WT BM but not with Rag1-deficient BM. Together, these results indicate that DRG sensory neurons sequester and retain antigen-specific antibodies released by antibody-secreting plasma cells. Coupling this work with previous studies implicating DRG sensory neurons in regulating antigen trafficking during immunization raises the interesting possibility that the nervous system collaborates with the immune system to regulate antigen-mediated responses.

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

    Science.gov (United States)

    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.

  9. 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

  10. The specificity of targeted vaccines for APC surface molecules influences the immune response phenotype.

    Directory of Open Access Journals (Sweden)

    Gunnveig Grødeland

    Full Text Available Different diseases require different immune responses for efficient protection. Thus, prophylactic vaccines should prime the immune system for the particular type of response needed for protection against a given infectious agent. We have here tested fusion DNA vaccines which encode proteins that bivalently target influenza hemagglutinins (HA to different surface molecules on antigen presenting cells (APC. We demonstrate that targeting to MHC class II molecules predominantly induced an antibody/Th2 response, whereas targeting to CCR1/3/5 predominantly induced a CD8(+/Th1 T cell response. With respect to antibodies, the polarizing effect was even more pronounced upon intramuscular (i.m delivery as compared to intradermal (i.d. vaccination. Despite these differences in induced immune responses, both vaccines protected against a viral challenge with influenza H1N1. Substitution of HA with ovalbumin (OVA demonstrated that polarization of immune responses, as a consequence of APC targeting specificity, could be extended to other antigens. Taken together, the results demonstrate that vaccination can be tailor-made to induce a particular phenotype of adaptive immune responses by specifically targeting different surface molecules on APCs.

  11. Rational design of nanoparticles towards targeting antigen-presenting cells and improved T cell priming.

    Science.gov (United States)

    Zupančič, Eva; Curato, Caterina; Paisana, Maria; Rodrigues, Catarina; Porat, Ziv; Viana, Ana S; Afonso, Carlos A M; Pinto, João; Gaspar, Rogério; Moreira, João N; Satchi-Fainaro, Ronit; Jung, Steffen; Florindo, Helena F

    2017-07-28

    Vaccination is a promising strategy to trigger and boost immune responses against cancer or infectious disease. We have designed, synthesized and characterized aliphatic-polyester (poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NP) to investigate how the nature of protein association (adsorbed versus entrapped) and polymer/surfactant concentrations impact on the generation and modulation of antigen-specific immune responses. The ability of the NP formulations to target dendritic cells (DC), be internalized and activate the T cells was characterized and optimized in vitro and in vivo using markers of DC activation and co-stimulatory molecules. Ovalbumin (OVA) was used as a model antigen in combination with the engraftment of CD4 + and CD8 + T cells, carrying a transgenic OVA-responding T cell receptor (TCR), to trace and characterize the activation of antigen-specific CD4 + and CD8 + lymph node T cells upon NP vaccination. Accordingly, the phenotype and frequency of immune cell stimulation induced by the NP loaded with OVA, isolated or in combination with synthetic unmethylated cytosine-phosphate-guanine (CpG) oligodeoxynucleotide (ODN) motifs, were characterized. DC-NP interactions increased with incubation time, presenting internalization values between 50 and 60% and 30-40%, in vitro and in vivo, respectively. Interestingly, animal immunization with antigen-adsorbed NP up-regulated major histocompatibility complex (MHC) class II (MHCII), while NP entrapping the antigen up-regulated MHCI, suggesting a more efficient cross-presentation. On the other hand, rather surprisingly, the surfactant used in the NP formulation had a major impact on the activation of antigen presenting cells (APC). In fact, DC collected from lymph nodes of animals immunized with NP prepared using poly(vinil alcohol) (PVA), as a surfactant, expressed significantly higher levels of CD86, MHCI and MHCII. In addition, those NP prepared with PVA and co-entrapping OVA and the toll

  12. Vaxfectin enhances antigen specific antibody titers and maintains Th1 type immune responses to plasmid DNA immunization.

    Science.gov (United States)

    Reyes, L; Hartikka, J; Bozoukova, V; Sukhu, L; Nishioka, W; Singh, G; Ferrari, M; Enas, J; Wheeler, C J; Manthorpe, M; Wloch, M K

    2001-06-14

    Antigen specific immune responses were characterized after intramuscular immunization of BALB/c mice with 5 antigen encoding plasmid DNAs (pDNAs) complexed with Vaxfectin, a cationic lipid formulation. Vaxfectin increased IgG titers for all of the antigens with no effect on the CTL responses to the 2 antigens for which CTL assays were performed. Both antigen specific IgG1 and IgG2a were increased, although IgG2a remained greater than IgG1. Furthermore, Vaxfectin had no effect on IFN-gamma or IL-4 production by splenocytes re-stimulated with antigen, suggesting that the Th1 type responses typical of intramuscular pDNA immunization were not altered. Studies with IL-6 -/- mice suggest that the antibody enhancement is IL-6 dependent and results in a correlative increase in antigen specific antibody secreting cells.

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

    Directory of Open Access Journals (Sweden)

    Daniel M Appledorn

    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.

  14. 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.

  15. Targeting innate immunity to downmodulate adaptive immunity and reverse type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Itoh A

    2017-05-01

    antigen-presenting cells (APCs that mediate decreased adaptive T-cell responses. Here, we review our current knowledge and suggest future prospects for targeting innate immunity in T1D immunotherapy. Keywords: type 1 diabetes, antigen-specific therapy, innate immunity, Toll-like receptors

  16. Vascular endothelium as a target of immune response in renal transplant rejection

    Directory of Open Access Journals (Sweden)

    Giovanni ePiotti

    2014-10-01

    Full Text Available This review of clinical and experimental studies aims at analysing the interplay between graft endothelium and host immune system in renal transplantation, and how it affects the survival of the graft. Graft endothelium is indeed the first barrier between self and non-self that is encountered by host lymphocytes upon reperfusion of vascularised solid transplants. Endothelial cells express all the major sets of antigens that elicit host immune response, and therefore represent a preferential target in organ rejection.Some of the antigens expressed by endothelial cells are target of the antibody-mediated response, such as the AB0 blood group system, the HLA and MICA systems, and the endothelial cell-restricted antigens; for each of these systems, the mechanisms of interaction and damage of both preformed and de novo donor-specific antibodies are reviewed along with their impact on renal graft survival. Moreover the rejection process can force injured endothelial cells to expose cryptic self-antigens, toward which an auto-immune response mounts, overlapping to the allo-immune response in the damaging of the graft. Not only are endothelial cells a passive target of the host immune response, but also an active player in lymphocyte activation; therefore their interaction with allogenic T-cells is analysed on the basis of experimental in vitro and in vivo studies, according to the patterns of expression of the HLA class I and II and the co-stimulatory molecules specific for cytotoxic and helper T-cells.Finally, as the response that follows transplantation has proven to be not necessarily destructive, the factors that foster graft endothelium functioning in spite of rejection, and how they could be therapeutically harnessed to promote long-term graft acceptance, are described: accommodation that is resistance of endothelial cells to donor-specific antibodies, and endothelial cell ability to induce Foxp3+ Regulatory T-cells, that are crucial mediators of

  17. Trial of using antibodies as carriers of alkylating agents. Pt. 2. Evaluation of ability to form /sup 32/P-cyclophosphamide + immune antibody complexes with homologous antigen

    Energy Technology Data Exchange (ETDEWEB)

    Trzeciak, J; Felus, E; Nolewajka, E; Szaflarski, J; Dudziak, Z [Slaska Akademia Medyczna, Katowice (Poland)

    1976-01-01

    /sup 32/P-cyclophosphamide was found to combine with ..gamma..-globulin fractions of immune sera. Immune sera incubated with /sup 32/P-cyclophosphamide retained ability to react specifically with homologou antigen in vitro in the system: MN antigens of human erythrocytes + rabbit anti-MN antibody, and probably reacted selectively with target antigens in vivo in the system: antigens of guinea pig kidney tissue + rabbit antibodies against these antigens. Hemagglutination, passive hemagglutination and precipitation in agar gel tests were used in the experiments. Ability to combine of the immune antibody + /sup 32/P-cyclophosphamide complex with homologous antigens was evaluated by measurements of radioactivity of studied materials (erythrocyte agglutinates and organ homogenates). The results indicate feasibility of using immune antibodies as carriers of cytostatic agents.

  18. Dendritic Cell Targeted Chitosan Nanoparticles for Nasal DNA Immunization against SARS CoV Nucleocapsid Protein

    OpenAIRE

    Raghuwanshi, Dharmendra; Mishra, Vivek; Das, Dipankar; Kaur, Kamaljit; Suresh, Mavanur R.

    2012-01-01

    This work investigates the formulation and in vivo efficacy of dendritic cell (DC) targeted plasmid DNA loaded biotinylated chitosan nanoparticles for nasal immunization against nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) as antigen. The induction of antigen-specific mucosal and systemic immune response at the site of virus entry is a major challenge for vaccine design. Here, we designed a strategy for non-invasive receptor mediated gene delivery to na...

  19. Targeting Antigens to Dec-205 on Dendritic Cells Induces Immune Protection in Experimental Colitis in Mice

    Science.gov (United States)

    Wadwa, Munisch; Klopfleisch, Robert; Buer, Jan; Westendorf, Astrid M.

    2016-01-01

    The endocytotic c-type lectin receptor DEC-205 is highly expressed on immature dendritic cells. In previous studies, it was shown that antigen-targeting to DEC-205 is a useful tool for the induction of antigen-specific Foxp3+ regulatory T cells and thereby can prevent inflammatory processes. However, whether this approach is sufficient to mediate tolerance in mucosal tissues like the gut is unknown. In this study, we established a new mouse model in which the adoptive transfer of naive hemagglutinin (HA)-specific CD4+Foxp3– T cells into VILLIN-HA transgenic mice leads to severe colitis. To analyze if antigen-targeting to DEC-205 could protect against inflammation of the gut, VILLIN-HA transgenic mice were injected with an antibody–antigen complex consisting of the immunogenic HA110–120 peptide coupled to an α-DEC-205 antibody (DEC-HA) before adoptive T cell transfer. DEC-HA-treated mice showed significantly less signs of intestinal inflammation as was demonstrated by reduced loss of body weight and histopathology in the gut. Strikingly, abrogated intestinal inflammation was mediated via the conversion of naive HA-specific CD4+Foxp3– T cells into HA-specific CD4+Foxp3+ regulatory T cells. In this study, we provide evidence that antigen-targeting to DEC-205 can be utilized for the induction of tolerance in mucosal organs that are confronted with large numbers of exogenous antigens. PMID:27141310

  20. Cellular immune responses against CT7 (MAGE-C1) and humoral responses against other cancer-testis antigens in multiple myeloma patients.

    Science.gov (United States)

    Lendvai, Nikoletta; Gnjatic, Sacha; Ritter, Erika; Mangone, Michael; Austin, Wayne; Reyner, Karina; Jayabalan, David; Niesvizky, Ruben; Jagannath, Sundar; Bhardwaj, Nina; Chen-Kiang, Selina; Old, Lloyd J; Cho, Hearn Jay

    2010-01-29

    The type I melanoma antigen gene (MAGE) proteins CT7 (MAGE-C1) and MAGE-A3 are commonly expressed in multiple myeloma (MM), and their expression correlates with increased plasma cell proliferation and poor clinical outcome. They belong to the cancer-testis antigen (CTAg) group of tumor-associated proteins, some of which elicit spontaneous immune responses in cancer patients. CT7 and MAGE-A3 are promising antigenic targets for therapeutic tumor vaccines in myeloma; therefore, it is critical to determine if they are immunogenic in MM patients. We analyzed cellular and humoral immune responses against CTAgs in patients with plasma cell dyscrasias: MM, monoclonal gammopathy of undetermined significance (MGUS), and Waldenström's macroglobulinemia (WM). Bone marrow lymphocytes from two of four untreated MM patients exhibited CT7-specific cellular immune responses as measured by an autologous cellular immunity assay, the first such immune response to CT7 to be reported in cancer patients. Sera from 24 patients were screened by ELISA for humoral immune responses to CTAgs. Two patients with MM demonstrated positive titers, one for MAGE-A1 and the other for SSX1. These data demonstrate that CTAgs, particularly CT7, are immunogenic in MM patients and merit further exploration as targets of immunological therapy in MM.

  1. Hantavirus Gc induces long-term immune protection via LAMP-targeting DNA vaccine strategy.

    Science.gov (United States)

    Jiang, Dong-Bo; Zhang, Jin-Peng; Cheng, Lin-Feng; Zhang, Guan-Wen; Li, Yun; Li, Zi-Chao; Lu, Zhen-Hua; Zhang, Zi-Xin; Lu, Yu-Chen; Zheng, Lian-He; Zhang, Fang-Lin; Yang, Kun

    2018-02-01

    Hemorrhagic fever with renal syndrome (HFRS) occurs widely throughout Eurasia. Unfortunately, there is no effective treatment, and prophylaxis remains the best option against the major pathogenic agent, hantaan virus (HTNV), which is an Old World hantavirus. However, the absence of cellular immune responses and immunological memory hampers acceptance of the current inactivated HFRS vaccine. Previous studies revealed that a lysosome-associated membrane protein 1 (LAMP1)-targeting strategy involving a DNA vaccine based on the HTNV glycoprotein Gn successfully conferred long-term immunity, and indicated that further research on Gc, another HTNV antigen, was warranted. Plasmids encoding Gc and lysosome-targeted Gc, designated pVAX-Gc and pVAX-LAMP/Gc, respectively, were constructed. Proteins of interest were identified by fluorescence microscopy following cell line transfection. Five groups of 20 female BALB/c mice were subjected to the following inoculations: inactivated HTNV vaccine, pVAX-LAMP/Gc, pVAX-Gc, and, as the negative controls, pVAX-LAMP or the blank vector pVAX1. Humoral and cellular immunity were assessed by enzyme-linked immunosorbent assays (ELISAs) and 15-mer peptide enzyme-linked immunospot (ELISpot) epitope mapping assays. Repeated immunization with pVAX-LAMP/Gc enhanced adaptive immune responses, as demonstrated by the specific and neutralizing antibody titers and increased IFN-γ production. The inactivated vaccine induced a comparable humoral reaction, but the negative controls only elicited insignificant responses. Using a mouse model of HTNV challenge, the in vivo protection conferred by the inactivated vaccine and Gc-based constructs (with/without LAMP recombination) was confirmed. Evidence of pan-epitope reactions highlighted the long-term cellular response to the LAMP-targeting strategy, and histological observations indicated the safety of the LAMP-targeting vaccines. The long-term protective immune responses induced by pVAX-LAMP/Gc may be

  2. Immuno-Oncology-The Translational Runway for Gene Therapy: Gene Therapeutics to Address Multiple Immune Targets.

    Science.gov (United States)

    Weß, Ludger; Schnieders, Frank

    2017-12-01

    Cancer therapy is once again experiencing a paradigm shift. This shift is based on extensive clinical experience demonstrating that cancer cannot be successfully fought by addressing only single targets or pathways. Even the combination of several neo-antigens in cancer vaccines is not sufficient for successful, lasting tumor eradication. The focus has therefore shifted to the immune system's role in cancer and the striking abilities of cancer cells to manipulate and/or deactivate the immune system. Researchers and pharma companies have started to target the processes and cells known to support immune surveillance and the elimination of tumor cells. Immune processes, however, require novel concepts beyond the traditional "single-target-single drug" paradigm and need parallel targeting of diverse cells and mechanisms. This review gives a perspective on the role of gene therapy technologies in the evolving immuno-oncology space and identifies gene therapy as a major driver in the development and regulation of effective cancer immunotherapy. Present challenges and breakthroughs ranging from chimeric antigen receptor T-cell therapy, gene-modified oncolytic viruses, combination cancer vaccines, to RNA therapeutics are spotlighted. Gene therapy is recognized as the most prominent technology enabling effective immuno-oncology strategies.

  3. Manipulating the in vivo immune response by targeted gene knockdown.

    Science.gov (United States)

    Lieberman, Judy

    2015-08-01

    Aptamers, nucleic acids selected for high affinity binding to proteins, can be used to activate or antagonize immune mediators or receptors in a location and cell-type specific manner and to enhance antigen presentation. They can also be linked to other molecules (other aptamers, siRNAs or miRNAs, proteins, toxins) to produce multifunctional compounds for targeted immune modulation in vivo. Aptamer-siRNA chimeras (AsiCs) that induce efficient cell-specific knockdown in immune cells in vitro and in vivo can be used as an immunological research tool or potentially as an immunomodulating therapeutic. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Topics in this issue: cancer testes antigens, immune checkpoints, inflammation associated with ischemia-reperfusion and integrin targeting.

    Science.gov (United States)

    Bot, Adrian; Chiriva-Internati, Maurizio

    2012-10-01

    This issue of the International Reviews of Immunology is dedicated to several topics: cancer immunotherapy, and basic and translational aspects of immunity. Two reviews, one focused on breast and the other on lung cancer, highlight the need to redefine the cancer testes antigens (CTAs) as novel information regarding their expression profile and biological role emerges. Two other reviews showcase pivotal molecules that keep in check immunity at two different levels: the transcription factor autoimmune regulator (AIRE) important to negative selection of the T-cell repertoire, and CD22 that limits the antigen-initiated B-cell response. Two other articles focus on the debated role of Toll-like receptors (TLRs) and inflammation in general, in ischemia-reperfusion lesions that follow cardiovascular disorders and stroke. Last but not the least, this issue hosts a review that discusses the role and translational potential of the α4 integrin for the treatment of inflammatory bowel disease (IBD).

  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

    Directory of Open Access Journals (Sweden)

    Helen eMokhtar

    2016-02-01

    Full Text Available 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 focussed on envelope glycoproteins to target virus-neutralising antibody responses. However, these approaches have failed to demonstrate the necessary efficacy to progress towards market. T cells are crucial to the control of many viruses through cytolysis and cytokine secretion. Since control of PRRSV infection is not dependent on the development of neutralising antibodies, it has been proposed that T cell mediated immunity plays a key role. We therefore hypothesised 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 immune by experimental infections with a closely-related (subtype 1 or divergent (subtype 3 PRRSV-1 strain. Dominant T cell IFN-γ responses were directed against the non-structural protein 5 (NSP5, and to a lesser extent, the matrix (M protein. The majority of NSP5-specific CD8 T cells and M-specific CD4 T cells expressed a putative effector memory phenotype and were polyfunctional as assessed by co-expression of TNF-α and mobilisation of the cytotoxic degranulation marker CD107a. Both antigens were generally well conserved amongst strains of both PRRSV genotypes. Thus M and NSP5 represent attractive vaccine candidate T cell antigens which should be evaluated further in the context of PRRSV vaccine development.

  6. Immunization with the recombinant antigen Ss-IR induces protective immunity to infection with Strongyloides stercoralis in mice.

    Science.gov (United States)

    Abraham, David; Hess, Jessica A; Mejia, Rojelio; Nolan, Thomas J; Lok, James B; Lustigman, Sara; Nutman, Thomas B

    2011-10-19

    Human intestinal infections with the nematode Strongyloides stercoralis remain a significant problem worldwide and a vaccine would be a useful addition to the tools available to prevent and control this infection. The goal of this study was to test single antigens for their efficacy in a vaccine against S. stercoralis larvae in mice. Alum was used as the adjuvant in these studies and antigens selected for analysis were either recognized by protective human IgG (Ss-TMY-1, Ss-EAT-6, and Ss-LEC-5) or were known to be highly immunogenic in humans (Ss-NIE-1 and Ss-IR). Only mice immunized with the Ss-IR antigen demonstrated a significant decrease of approximately 80% in the survival of larval parasites in the challenge infection. Antibodies, recovered from mice with protective immunity to S. stercoralis after immunization with Ss-IR, were used to locate the antigen in the larvae. Confocal microscopy revealed that IgG from mice immunized with Ss-IR bound to the surface of the parasites and observations by electron microscopy indicated that IgG bound to granules in the glandular esophagus. Serum collected from mice immunized with Ss-IR passively transferred immunity to naïve mice. These studies demonstrate that Ss-IR, in combination with alum, induces high levels of protective immunity through an antibody dependent mechanism and may therefore be suitable for further development as a vaccine against human strongyloidiasis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Toll-like receptor activation enhances cell-mediated immunity induced by an antibody vaccine targeting human dendritic cells

    Directory of Open Access Journals (Sweden)

    Berger Marc A

    2007-01-01

    Full Text Available Abstract Previously, we have successfully targeted the mannose receptor (MR expressed on monocyte-derived dendritic cells (DCs using a fully human MR-specific antibody, B11, as a vehicle to deliver whole protein tumor antigens such as the human chorionic gonadotropin hormone (hCGβ. Since MRs play a role in bridging innate immunity with adaptive immunity we have explored several toll-like receptor (TLR-specific ligands that may synergize with MR targeting and be applicable as adjuvants in the clinic. We demonstrate that antigen-specific helper and cytolytic T cells from both healthy donors and cancer patients were effectively primed with B11-hCGβ-treated autologous DCs when a combination of one or several TLR ligands is used. Specifically, concomitant signaling of DCs via TLR3 with dsRNA (poly I:C and DC TLR 7/8 with Resiquimod (R-848, respectively, elicited efficient antigen presentation-mediated by MR-targeting. We demonstrate that MR and TLRs contribute towards maturation and activation of DCs by a mechanism that may be driven by a combination of adjuvant and antibody vaccines that specifically deliver antigenic targets to DCs.

  8. Characterization of Specific Immune Responses to Different Aspergillus Antigens during the Course of Invasive Aspergillosis in Hematologic Patients

    Science.gov (United States)

    Beauvais, Anne; Beau, Remi; Candoni, Anna; Maertens, Johan; Rossi, Giulio; Morselli, Monica; Zanetti, Eleonora; Quadrelli, Chiara; Codeluppi, Mauro; Guaraldi, Giovanni; Pagano, Livio; Caira, Morena; Giovane, Cinzia Del; Maccaferri, Monica; Stefani, Alessandro; Morandi, Uliano; Tazzioli, Giovanni; Girardis, Massimo; Delia, Mario; Specchia, Giorgina; Longo, Giuseppe; Marasca, Roberto; Narni, Franco; Merli, Francesco; Imovilli, Annalisa; Apolone, Giovanni; Carvalho, Agostinho; Comoli, Patrizia; Romani, Luigina; Latgè, Jean Paul; Luppi, Mario

    2013-01-01

    Several studies in mouse model of invasive aspergillosis (IA) and in healthy donors have shown that different Aspergillus antigens may stimulate different adaptive immune responses. However, the occurrence of Aspergillus-specific T cells have not yet been reported in patients with the disease. In patients with IA, we have investigated during the infection: a) whether and how specific T-cell responses to different Aspergillus antigens occur and develop; b) which antigens elicit the highest frequencies of protective immune responses and, c) whether such protective T cells could be expanded ex-vivo. Forty hematologic patients have been studied, including 22 patients with IA and 18 controls. Specific T cells producing IL-10, IFN-γ, IL-4 and IL-17A have been characterized through enzyme linked immunospot and cytokine secretion assays on 88 peripheral blood (PB) samples, by using the following recombinant antigens: GEL1p, CRF1p, PEP1p, SOD1p, α1–3glucan, β1–3glucan, galactomannan. Specific T cells were expanded through short term culture. Aspergillus-specific T cells producing non-protective interleukin-10 (IL-10) and protective interferon-gamma (IFN-γ) have been detected to all the antigens only in IA patients. Lower numbers of specific T cells producing IL-4 and IL-17A have also been shown. Protective T cells targeted predominantly Aspergillus cell wall antigens, tended to increase during the IA course and to be associated with a better clinical outcome. Aspergillus-specific T cells could be successfully generated from the PB of 8 out of 8 patients with IA and included cytotoxic subsets able to lyse Aspergillus hyphae. Aspergillus specific T-cell responses contribute to the clearance of the pathogen in immunosuppressed patients with IA and Aspergillus cell wall antigens are those mainly targeted by protective immune responses. Cytotoxic specific T cells can be expanded from immunosuppressed patients even during the infection by using the above mentioned

  9. A viral vectored prime-boost immunization regime targeting the malaria Pfs25 antigen induces transmission-blocking activity.

    Directory of Open Access Journals (Sweden)

    Anna L Goodman

    Full Text Available The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63, human adenovirus serotype 5 (AdHu5 and modified vaccinia virus Ankara (MVA viral vectored vaccines. Two immunizations were administered to mice in a heterologous prime-boost regime. Immunization of mice with AdHu5 Pfs25 at week 0 and MVA Pfs25 at week 10 (Ad-MVA Pfs25 resulted in high anti-Pfs25 IgG titers, consisting of predominantly isotypes IgG1 and IgG2a. A single priming immunization with ChAd63 Pfs25 was as effective as AdHu5 Pfs25 with respect to ELISA titers at 8 weeks post-immunization. Sera from Ad-MVA Pfs25 immunized mice inhibited the transmission of P. falciparum to the mosquito both ex vivo and in vivo. In a standard membrane-feeding assay using NF54 strain P. falciparum, oocyst intensity in Anopheles stephensi mosquitoes was significantly reduced in an IgG concentration-dependent manner when compared to control feeds (96% reduction of intensity, 78% reduction in prevalence at a 1 in 5 dilution of sera. In addition, an in vivo transmission-blocking effect was also demonstrated by direct feeding of immunized mice infected with Pfs25DR3, a chimeric P. berghei line expressing Pfs25 in place of endogenous Pbs25. In this assay the density of Pfs25DR3 oocysts was significantly reduced when mosquitoes were fed on vaccinated as compared to control mice (67% reduction of intensity, 28% reduction in prevalence and specific IgG titer correlated with efficacy. These data confirm the utility of the adenovirus-MVA vaccine platform for the induction of antibodies with transmission-blocking activity, and support the continued development of this alternative approach to transmission-blocking malaria subunit

  10. Pooled protein immunization for identification of cell surface antigens in Streptococcus sanguinis.

    Directory of Open Access Journals (Sweden)

    Xiuchun Ge

    2010-07-01

    Full Text Available Available bacterial genomes provide opportunities for screening vaccines by reverse vaccinology. Efficient identification of surface antigens is required to reduce time and animal cost in this technology. We developed an approach to identify surface antigens rapidly in Streptococcus sanguinis, a common infective endocarditis causative species.We applied bioinformatics for antigen prediction and pooled antigens for immunization. Forty-seven surface-exposed proteins including 28 lipoproteins and 19 cell wall-anchored proteins were chosen based on computer algorithms and comparative genomic analyses. Eight proteins among these candidates and 2 other proteins were pooled together to immunize rabbits. The antiserum reacted strongly with each protein and with S. sanguinis whole cells. Affinity chromatography was used to purify the antibodies to 9 of the antigen pool components. Competitive ELISA and FACS results indicated that these 9 proteins were exposed on S. sanguinis cell surfaces. The purified antibodies had demonstrable opsonic activity.The results indicate that immunization with pooled proteins, in combination with affinity purification, and comprehensive immunological assays may facilitate cell surface antigen identification to combat infectious diseases.

  11. Pooled protein immunization for identification of cell surface antigens in Streptococcus sanguinis.

    Science.gov (United States)

    Ge, Xiuchun; Kitten, Todd; Munro, Cindy L; Conrad, Daniel H; Xu, Ping

    2010-07-26

    Available bacterial genomes provide opportunities for screening vaccines by reverse vaccinology. Efficient identification of surface antigens is required to reduce time and animal cost in this technology. We developed an approach to identify surface antigens rapidly in Streptococcus sanguinis, a common infective endocarditis causative species. We applied bioinformatics for antigen prediction and pooled antigens for immunization. Forty-seven surface-exposed proteins including 28 lipoproteins and 19 cell wall-anchored proteins were chosen based on computer algorithms and comparative genomic analyses. Eight proteins among these candidates and 2 other proteins were pooled together to immunize rabbits. The antiserum reacted strongly with each protein and with S. sanguinis whole cells. Affinity chromatography was used to purify the antibodies to 9 of the antigen pool components. Competitive ELISA and FACS results indicated that these 9 proteins were exposed on S. sanguinis cell surfaces. The purified antibodies had demonstrable opsonic activity. The results indicate that immunization with pooled proteins, in combination with affinity purification, and comprehensive immunological assays may facilitate cell surface antigen identification to combat infectious diseases.

  12. A single point in protein trafficking by Plasmodium falciparum determines the expression of major antigens on the surface of infected erythrocytes targeted by human antibodies.

    Science.gov (United States)

    Chan, Jo-Anne; Howell, Katherine B; Langer, Christine; Maier, Alexander G; Hasang, Wina; Rogerson, Stephen J; Petter, Michaela; Chesson, Joanne; Stanisic, Danielle I; Duffy, Michael F; Cooke, Brian M; Siba, Peter M; Mueller, Ivo; Bull, Peter C; Marsh, Kevin; Fowkes, Freya J I; Beeson, James G

    2016-11-01

    Antibodies to blood-stage antigens of Plasmodium falciparum play a pivotal role in human immunity to malaria. During parasite development, multiple proteins are trafficked from the intracellular parasite to the surface of P. falciparum-infected erythrocytes (IEs). However, the relative importance of different proteins as targets of acquired antibodies, and key pathways involved in trafficking major antigens remain to be clearly defined. We quantified antibodies to surface antigens among children, adults, and pregnant women from different malaria-exposed regions. We quantified the importance of antigens as antibody targets using genetically engineered P. falciparum with modified surface antigen expression. Genetic deletion of the trafficking protein skeleton-binding protein-1 (SBP1), which is involved in trafficking the surface antigen PfEMP1, led to a dramatic reduction in antibody recognition of IEs and the ability of human antibodies to promote opsonic phagocytosis of IEs, a key mechanism of parasite clearance. The great majority of antibody epitopes on the IE surface were SBP1-dependent. This was demonstrated using parasite isolates with different genetic or phenotypic backgrounds, and among antibodies from children, adults, and pregnant women in different populations. Comparisons of antibody reactivity to parasite isolates with SBP1 deletion or inhibited PfEMP1 expression suggest that PfEMP1 is the dominant target of acquired human antibodies, and that other P. falciparum IE surface proteins are minor targets. These results establish SBP1 as part of a critical pathway for the trafficking of major surface antigens targeted by human immunity, and have key implications for vaccine development, and quantifying immunity in populations.

  13. Novel Antitumor Strategy Utilizing a Plasmid Expressing a Mycobacterium tuberculosis Antigen as a “Danger Signal” to Block Immune Escape of Tumor Cells

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Koyama

    2015-07-01

    Full Text Available Immune escape of tumor cells is one of the main obstacles hindering the effectiveness of cancer immunotherapy. We developed a novel strategy to block immune escape by transfecting tumor cells in vivo with genes of pathogenic antigens from Mycobacterium tuberculosis (TB. This induces presentation of the TB antigen on tumor cell surfaces, which can be recognized by antigen presenting cells (APCs as a “danger signal” to stimulate antitumor immune response. This strategy is also expected to amplify the immune response against tumor-associated antigens, and block immune escape of the tumor. DNA/PEI/chondroitin sulfate ternary complex is a highly effective non-viral gene vector system for in vivo transfection. A therapeutic complex was prepared using a plasmid encoding the TB antigen, early secretory antigenic target-6 (ESAT-6. This was injected intratumorally into syngeneic tumor-bearing mice, and induced significant tumor growth suppression comparable to or higher than similar complexes expressing cytokines such as interleukin-2 (IL-2 and interleukin-12 (IL-12. Co-transfection of the cytokine-genes and the ESAT-6-gene enhanced the antitumor efficacy of either treatment alone. In addition, complete tumor regression was achieved with the combination of ESAT-6 and IL-2 genes.

  14. Active immunization with an octa-valent Staphylococcus aureus antigen mixture in models of S. aureus bacteremia and skin infection in mice.

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    Sanne van den Berg

    Full Text Available Proteomic studies with different Staphylococcus aureus isolates have shown that the cell surface-exposed and secreted proteins IsaA, LytM, Nuc, the propeptide of Atl (pro-Atl and four phenol-soluble modulins α (PSMα are invariantly produced by this pathogen. Therefore the present study was aimed at investigating whether these proteins can be used for active immunization against S. aureus infection in mouse models of bacteremia and skin infection. To this end, recombinant His-tagged fusions of IsaA, LytM, Nuc and pro-Atl were isolated from Lactococcus lactis or Escherichia coli, while the PSMα1-4 peptides were chemically synthesized. Importantly, patients colonized by S. aureus showed significant immunoglobulin G (IgG responses against all eight antigens. BALB/cBYJ mice were immunized subcutaneously with a mixture of the antigens at day one (5 μg each, and boosted twice (25 μg of each antigen with 28 days interval. This resulted in high IgG responses against all antigens although the response against pro-Atl was around one log lower compared to the other antigens. Compared to placebo-immunized mice, immunization with the octa-valent antigen mixture did not reduce the S. aureus isolate P load in blood, lungs, spleen, liver, and kidneys in a bacteremia model in which the animals were challenged for 14 days with a primary load of 3 × 10(5 CFU. Discomfort scores and animal survival rates over 14 days did not differ between immunized mice and placebo-immunized mice upon bacteremia with S. aureus USA300 (6 × 10(5 CFU. In addition, this immunization did not reduce the S. aureus isolate P load in mice with skin infection. These results show that the target antigens are immunogenic in both humans and mice, but in the used animal models do not result in protection against S. aureus infection.

  15. Increased serum anti-mycobacterial antibody titers in rheumatoid arthritis patients: Is there any specific antigenic target?

    International Nuclear Information System (INIS)

    Cetin, Emel S.; Aksoy, Ali M

    2007-01-01

    Objective was to investigate the presence of immunoreactivity against mycobacterial antigens in the sera of patients with rheumatoid arthritis (Ra) and to detect the target of the immune reaction. This study was carried out on 60 patients with RA, and 25 patients with no joint diseases in the laboratory of Clinical Microbiology Department of Ankara University Medical Faculty, Ankara, Turkey between July 2003 to January 2004. Secreted and cellular antigens of Mycobacterium tuberculosis (M. tuberculosis) H37Rv and Mycobacterium bovis (M. bovis) were isolated and purified by high performance liquid chromatography to antigenic fractions. The immunoreactivity of patient and control sera against these antigens were determined by enzyme-linked immunosorbent assay (ELISA). Immunoreactivity against mycobacterial antigens in RA patients were significantly higher than controls. Significant difference between patients and controls has been determined with M. bovis Bacillus Calmette Guerin (BCG) culture fluid and sonicate antigens, but not with M. tuberculosis H37Rv. This suggests that the antigen triggering immune response in patients with RA may belong to or mainly expressed on M. bovis BCG. The ELISA results showed significant difference between RA patients and controls with all antigenic fractions. Presence of increased immunoreactivity against mycobacterial antigens in the sera of patients with RA was detected. When statistical analysis was considered, we cannot put forward any antigenic fraction alone as the one responsible for the increased reactivity. (author)

  16. B cells as a target of immune modulation

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    Hawker Kathleen

    2009-01-01

    Full Text Available B cells have recently been identified as an integral component of the immune system; they play a part in autoimmunity through antigen presentation, antibody secretion, and complement activation. Animal models of multiple sclerosis (MS suggest that myelin destruction is partly mediated through B cell activation (and plasmablasts. MS patients with evidence of B cell involvement, as compared to those without, tend to have a worse prognosis. Finally, the significant decrease in new gadolinium-enhancing lesions, new T2 lesions, and relapses in MS patients treated with rituximab (a monoclonal antibody against CD20 on B cells leads us to the conclusion that B cells play an important role in MS and that immune modulation of these cells may ameliorate the disease. This article will explore the role of B cells in MS and the rationale for the development of B cell-targeted therapeutics. MS is an immune-mediated disease that affects over 2 million people worldwide and is the number one cause of disability in young patients. Most therapeutic targets have focused on T cells; however, recently, the focus has shifted to the role of B cells in the pathogenesis of MS and the potential of B cells as a therapeutic target.

  17. Altered neurological function in mice immunized with early endosome antigen 1

    Directory of Open Access Journals (Sweden)

    Fritzler Marvin J

    2004-01-01

    Full Text Available Abstract Background Autoantibodies directed against the 160 kDa endosome protein early endosome antigen 1 (EEA1 are seen in patients with neurological diseases. To determine if antibodies to EEA1 have a neuropathological effect, mice from three major histocompatability haplotype backgrounds (H2q, H2b and H2d were immunized with EEA1 (amino acids 82–1411 that was previously shown to contain the target EEA1 epitopes. The mice were then subjected to five neuro-behavioural tests: grid walking, forelimb strength, open field, reaching and rotarod. Results The immunized SWR/J mice with sustained anti-EEA1 antibodies had significantly reduced forelimb strength than the control non-immune mice of the same strain, and BALB/CJ immune mice demonstrated significantly more forelimb errors on the grid walk test than the control group. Conclusions Antibodies to recombinant EEA1 in mice may mediate neurological deficits that are consistent with clinical features of some humans that spontaneously develop anti-EEA1 autoantibodies.

  18. Assessment of humoral immune responses to blood-stage malaria antigens following ChAd63-MVA immunization, controlled human malaria infection and natural exposure.

    Science.gov (United States)

    Biswas, Sumi; Choudhary, Prateek; Elias, Sean C; Miura, Kazutoyo; Milne, Kathryn H; de Cassan, Simone C; Collins, Katharine A; Halstead, Fenella D; Bliss, Carly M; Ewer, Katie J; Osier, Faith H; Hodgson, Susanne H; Duncan, Christopher J A; O'Hara, Geraldine A; Long, Carole A; Hill, Adrian V S; Draper, Simon J

    2014-01-01

    The development of protective vaccines against many difficult infectious pathogens will necessitate the induction of effective antibody responses. Here we assess humoral immune responses against two antigens from the blood-stage merozoite of the Plasmodium falciparum human malaria parasite--MSP1 and AMA1. These antigens were delivered to healthy malaria-naïve adult volunteers in Phase Ia clinical trials using recombinant replication-deficient viral vectors--ChAd63 to prime the immune response and MVA to boost. In subsequent Phase IIa clinical trials, immunized volunteers underwent controlled human malaria infection (CHMI) with P. falciparum to assess vaccine efficacy, whereby all but one volunteer developed low-density blood-stage parasitemia. Here we assess serum antibody responses against both the MSP1 and AMA1 antigens following i) ChAd63-MVA immunization, ii) immunization and CHMI, and iii) primary malaria exposure in the context of CHMI in unimmunized control volunteers. Responses were also assessed in a cohort of naturally-immune Kenyan adults to provide comparison with those induced by a lifetime of natural malaria exposure. Serum antibody responses against MSP1 and AMA1 were characterized in terms of i) total IgG responses before and after CHMI, ii) responses to allelic variants of MSP1 and AMA1, iii) functional growth inhibitory activity (GIA), iv) IgG avidity, and v) isotype responses (IgG1-4, IgA and IgM). These data provide the first in-depth assessment of the quality of adenovirus-MVA vaccine-induced antibody responses in humans, along with assessment of how these responses are modulated by subsequent low-density parasite exposure. Notable differences were observed in qualitative aspects of the human antibody responses against these malaria antigens depending on the means of their induction and/or exposure of the host to the malaria parasite. Given the continued clinical development of viral vectored vaccines for malaria and a range of other diseases

  19. Assessment of humoral immune responses to blood-stage malaria antigens following ChAd63-MVA immunization, controlled human malaria infection and natural exposure.

    Directory of Open Access Journals (Sweden)

    Sumi Biswas

    Full Text Available The development of protective vaccines against many difficult infectious pathogens will necessitate the induction of effective antibody responses. Here we assess humoral immune responses against two antigens from the blood-stage merozoite of the Plasmodium falciparum human malaria parasite--MSP1 and AMA1. These antigens were delivered to healthy malaria-naïve adult volunteers in Phase Ia clinical trials using recombinant replication-deficient viral vectors--ChAd63 to prime the immune response and MVA to boost. In subsequent Phase IIa clinical trials, immunized volunteers underwent controlled human malaria infection (CHMI with P. falciparum to assess vaccine efficacy, whereby all but one volunteer developed low-density blood-stage parasitemia. Here we assess serum antibody responses against both the MSP1 and AMA1 antigens following i ChAd63-MVA immunization, ii immunization and CHMI, and iii primary malaria exposure in the context of CHMI in unimmunized control volunteers. Responses were also assessed in a cohort of naturally-immune Kenyan adults to provide comparison with those induced by a lifetime of natural malaria exposure. Serum antibody responses against MSP1 and AMA1 were characterized in terms of i total IgG responses before and after CHMI, ii responses to allelic variants of MSP1 and AMA1, iii functional growth inhibitory activity (GIA, iv IgG avidity, and v isotype responses (IgG1-4, IgA and IgM. These data provide the first in-depth assessment of the quality of adenovirus-MVA vaccine-induced antibody responses in humans, along with assessment of how these responses are modulated by subsequent low-density parasite exposure. Notable differences were observed in qualitative aspects of the human antibody responses against these malaria antigens depending on the means of their induction and/or exposure of the host to the malaria parasite. Given the continued clinical development of viral vectored vaccines for malaria and a range of other

  20. Environmental proxies of antigen exposure explain variation in immune investment better than indices of pace of life.

    Science.gov (United States)

    Horrocks, Nicholas P C; Hegemann, Arne; Ostrowski, Stéphane; Ndithia, Henry; Shobrak, Mohammed; Williams, Joseph B; Matson, Kevin D; Tieleman, B I

    2015-01-01

    Investment in immune defences is predicted to covary with a variety of ecologically and evolutionarily relevant axes, with pace of life and environmental antigen exposure being two examples. These axes may themselves covary directly or inversely, and such relationships can lead to conflicting predictions regarding immune investment. If pace of life shapes immune investment then, following life history theory, slow-living, arid zone and tropical species should invest more in immunity than fast-living temperate species. Alternatively, if antigen exposure drives immune investment, then species in antigen-rich tropical and temperate environments are predicted to exhibit higher immune indices than species from antigen-poor arid locations. To test these contrasting predictions we investigated how variation in pace of life and antigen exposure influence immune investment in related lark species (Alaudidae) with differing life histories and predicted risks of exposure to environmental microbes and parasites. We used clutch size and total number of eggs laid per year as indicators of pace of life, and aridity, and the climatic variables that influence aridity, as correlates of antigen abundance. We quantified immune investment by measuring four indices of innate immunity. Pace of life explained little of the variation in immune investment, and only one immune measure correlated significantly with pace of life, but not in the predicted direction. Conversely, aridity, our proxy for environmental antigen exposure, was predictive of immune investment, and larks in more mesic environments had higher immune indices than those living in arid, low-risk locations. Our study suggests that abiotic environmental variables with strong ties to environmental antigen exposure can be important correlates of immunological variation.

  1. Nanoparticle-based B-cell targeting vaccines: Tailoring of humoral immune responses by functionalization with different TLR-ligands.

    Science.gov (United States)

    Zilker, Claudia; Kozlova, Diana; Sokolova, Viktoriya; Yan, Huimin; Epple, Matthias; Überla, Klaus; Temchura, Vladimir

    2017-01-01

    Induction of an appropriate type of humoral immune response during vaccination is essential for protection against viral and bacterial infections. We recently observed that biodegradable calcium phosphate (CaP) nanoparticles coated with proteins efficiently targeted and activated naïve antigen-specific B-cells in vitro. We now compared different administration routes for CaP-nanoparticles and demonstrated that intramuscular immunization with such CaP-nanoparticles induced stronger immune responses than immunization with monovalent antigen. Additional functionalization of the CaP-nanoparticles with TRL-ligands allowed modulating the IgG subtype response and the level of mucosal IgA antibodies. CpG-containing CaP-nanoparticles were as immunogenic as a virus-like particle vaccine. Functionalization of CaP-nanoparticles with T-helper cell epitopes or CpG also allowed overcoming lack of T-cell help. Thus, our results indicate that CaP-nanoparticle-based B-cell targeting vaccines functionalized with TLR-ligands can serve as a versatile platform for efficient induction and modulation of humoral immune responses in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

  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. 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.

  4. A T-cell response to a liver-stage Plasmodium antigen is not boosted by repeated sporozoite immunizations

    Science.gov (United States)

    Murphy, Sean C.; Kas, Arnold; Stone, Brad C.; Bevan, Michael J.

    2013-01-01

    Development of an antimalarial subunit vaccine inducing protective cytotoxic T lymphocyte (CTL)-mediated immunity could pave the way for malaria eradication. Experimental immunization with sporozoites induces this type of protective response, but the extremely large number of proteins expressed by Plasmodium parasites has so far prohibited the identification of sufficient discrete T-cell antigens to develop subunit vaccines that produce sterile immunity. Here, using mice singly immunized with Plasmodium yoelii sporozoites and high-throughput screening, we identified a unique CTL response against the parasite ribosomal L3 protein. Unlike CTL responses to the circumsporozoite protein (CSP), the population of L3-specific CTLs was not expanded by multiple sporozoite immunizations. CSP is abundant in the sporozoite itself, whereas L3 expression does not increase until the liver stage. The response induced by a single immunization with sporozoites reduces the parasite load in the liver so greatly during subsequent immunizations that L3-specific responses are only generated during the primary exposure. Functional L3-specific CTLs can, however, be expanded by heterologous prime-boost regimens. Thus, although repeat sporozoite immunization expands responses to preformed antigens like CSP that are present in the sporozoite itself, this immunization strategy may not expand CTLs targeting parasite proteins that are synthesized later. Heterologous strategies may be needed to increase CTL responses across the entire spectrum of Plasmodium liver-stage proteins. PMID:23530242

  5. Immune responses to red blood cell antigens

    NARCIS (Netherlands)

    Stegmann, T.C.

    2016-01-01

    The research described in this thesis is aimed towards elucidation of the mechanism of action of anti-D. Anti-D is administered prophylactivly to prevent alloimmunization against the immunogenic D-antigen to D⁻ pregnant women carrying a D⁺ fetus. The plasma of women who became immunized during

  6. No protection in chickens immunized by the oral or intra-muscular immunization route with Ascaridia galli soluble antigen

    DEFF Research Database (Denmark)

    Andersen, Janne Pleidrup; Norup, Liselotte R.; Dalgaard, Tina S.

    2013-01-01

    In chickens, the nematode Ascaridia galli is found with prevalences of up to 100% causing economic losses to farmers. No avian nematode vaccines have yet been developed and detailed knowledge about the chicken immune response towards A. galli is therefore of great importance. The objective...... of this study was to evaluate the induction of protective immune responses to A. galli soluble antigen by different immunization routes. Chickens were immunized with a crude extract of A. galli via an oral or intra-muscular route using cholera toxin B subunit as adjuvant and subsequently challenged with A...... immunization had an effect on both Th1 and Th2 cytokines in caecal tonsils and Meckel's diverticulum. Thus both humoral and cellular immune responses are inducible by soluble A. galli antigen, but in this study no protection against the parasite was achieved....

  7. 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

  8. 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.

  9. Immunotherapy Targets in Pediatric Cancer

    International Nuclear Information System (INIS)

    Orentas, Rimas J.; Lee, Daniel W.; Mackall, Crystal

    2012-01-01

    Immunotherapy for cancer has shown increasing success and there is ample evidence to expect that progress gleaned in immune targeting of adult cancers can be translated to pediatric oncology. This manuscript reviews principles that guide selection of targets for immunotherapy of cancer, emphasizing the similarities and distinctions between oncogene-inhibition targets and immune targets. It follows with a detailed review of molecules expressed by pediatric tumors that are already under study as immune targets or are good candidates for future studies of immune targeting. Distinctions are made between cell surface antigens that can be targeted in an MHC independent manner using antibodies, antibody derivatives, or chimeric antigen receptors versus intracellular antigens which must be targeted with MHC restricted T cell therapies. Among the most advanced immune targets for childhood cancer are CD19 and CD22 on hematologic malignancies, GD2 on solid tumors, and NY-ESO-1 expressed by a majority of synovial sarcomas, but several other molecules reviewed here also have properties which suggest that they too could serve as effective targets for immunotherapy of childhood cancer.

  10. Immunotherapy Targets in Pediatric Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Orentas, Rimas J.; Lee, Daniel W.; Mackall, Crystal, E-mail: rimas.orentas@nih.gov, E-mail: mackallc@mail.nih.gov [Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States)

    2012-01-30

    Immunotherapy for cancer has shown increasing success and there is ample evidence to expect that progress gleaned in immune targeting of adult cancers can be translated to pediatric oncology. This manuscript reviews principles that guide selection of targets for immunotherapy of cancer, emphasizing the similarities and distinctions between oncogene-inhibition targets and immune targets. It follows with a detailed review of molecules expressed by pediatric tumors that are already under study as immune targets or are good candidates for future studies of immune targeting. Distinctions are made between cell surface antigens that can be targeted in an MHC independent manner using antibodies, antibody derivatives, or chimeric antigen receptors versus intracellular antigens which must be targeted with MHC restricted T cell therapies. Among the most advanced immune targets for childhood cancer are CD19 and CD22 on hematologic malignancies, GD2 on solid tumors, and NY-ESO-1 expressed by a majority of synovial sarcomas, but several other molecules reviewed here also have properties which suggest that they too could serve as effective targets for immunotherapy of childhood cancer.

  11. Host-Brucella interactions and the Brucella genome as tools for subunit antigen discovery and immunization against brucellosis

    Science.gov (United States)

    Gomez, Gabriel; Adams, Leslie G.; Rice-Ficht, Allison; Ficht, Thomas A.

    2013-01-01

    Vaccination is the most important approach to counteract infectious diseases. Thus, the development of new and improved vaccines for existing, emerging, and re-emerging diseases is an area of great interest to the scientific community and general public. Traditional approaches to subunit antigen discovery and vaccine development lack consideration for the critical aspects of public safety and activation of relevant protective host immunity. The availability of genomic sequences for pathogenic Brucella spp. and their hosts have led to development of systems-wide analytical tools that have provided a better understanding of host and pathogen physiology while also beginning to unravel the intricacies at the host-pathogen interface. Advances in pathogen biology, host immunology, and host-agent interactions have the potential to serve as a platform for the design and implementation of better-targeted antigen discovery approaches. With emphasis on Brucella spp., we probe the biological aspects of host and pathogen that merit consideration in the targeted design of subunit antigen discovery and vaccine development. PMID:23720712

  12. Antigen-targeting strategies using single-domain antibody fragments

    NARCIS (Netherlands)

    Duarte, Joao Nuno Silva

    2017-01-01

    Antibodies display high selectivity and affinity and have been the preferred platform for antigen targeting. Despite the development of antigen-delivery systems that enable T cell activation, targeting approaches that enhance antibody responses need improvement. This need specially applies to poorly

  13. Immunogenicity is unrelated to protective immunity when induced by soluble and particulate antigens from Nocardia brasiliensis in BALB/c mice.

    Science.gov (United States)

    Salinas-Carmona, Mario C; Ramos, Alma I; Pérez-Rivera, Isabel

    2006-08-01

    Cell-mediated immunity plays a major role in protection against intracellular microbes. Nocardia brasiliensis is a facultative intracellular pathogen that causes chronic actinomycetoma. In this work, we injected BALB/c mice with soluble P24 and particulate antigens from N. brasiliensis. A higher antibody titer and lymphocyte proliferation was induced by the particulate antigen than by the soluble antigen. However, five months after antigen injection, antibody concentration and lymphocyte proliferation were similar. An increase in CD45R and CD4 T cells was unrelated to protective immunity. Active immunization with soluble or particulate antigens induced complete protection during the primary immune response. This protective response was IgM mediated. The higher immunogenicity was not related to protective immunity since the particulate antigen induced protection similar to the soluble antigen. Using particulate antigens for vaccination guarantees a stronger immune response, local and systemic side effects, but not necessarily protection.

  14. Oncogenic cancer/testis antigens

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Andersen, Mads H; Ditzel, Henrik J

    2015-01-01

    Recent developments have set the stage for immunotherapy as a supplement to conventional cancer treatment. Consequently, a significant effort is required to further improve efficacy and specificity, particularly the identification of optimal therapeutic targets for clinical testing. Cancer....../testis antigens are immunogenic, highly cancer-specific, and frequently expressed in various types of cancer, which make them promising candidate targets for cancer immunotherapy, including cancer vaccination and adoptive T-cell transfer with chimeric T-cell receptors. Our current understanding of tumor...... immunology and immune escape suggests that targeting oncogenic antigens may be beneficial, meaning that identification of cancer/testis antigens with oncogenic properties is of high priority. Recent work from our lab and others provide evidence that many cancer/testis antigens, in fact, have oncogenic...

  15. Application of fluorescent monocytes for probing immune complexes on antigen microarrays.

    Directory of Open Access Journals (Sweden)

    Zoltán Szittner

    Full Text Available Microarrayed antigens are used for identifying serum antibodies with given specificities and for generating binding profiles. Antibodies bind to these arrayed antigens forming immune complexes and are conventionally identified by secondary labelled antibodies.In the body immune complexes are identified by bone marrow derived phagocytic cells, such as monocytes. In our work we were looking into the possibility of replacing secondary antibodies with monocytoid cells for the generation of antibody profiles. Using the human monocytoid cell line U937, which expresses cell surface receptors for immune complex components, we show that cell adhesion is completely dependent on the interaction of IgG heavy chains and Fcγ receptors, and this recognition is susceptible to differences between heavy chain structures and their glycosylation. We also report data on a possible application of this system in autoimmune diagnostics.Compared to secondary antibodies, fluorescent monocytesas biosensors are superior in reflecting biological functions of microarray-bound antibodies and represent an easy and robust alternative for profiling interactions between serum proteins and antigens.

  16. Identification and characterization of Ixodes scapularis antigens that elicit tick immunity using yeast surface display.

    Directory of Open Access Journals (Sweden)

    Tim J Schuijt

    2011-01-01

    Full Text Available Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary antigens that react with tick-immune serum. We constructed an Ixodes scapularis nymphal salivary gland yeast surface display library and screened the library with nymph-immune rabbit sera and identified five salivary antigens. Four of these proteins, designated P8, P19, P23 and P32, had a predicted signal sequence. We generated recombinant (r P8, P19 and P23 in a Drosophila expression system for functional and immunization studies. rP8 showed anti-complement activity and rP23 demonstrated anti-coagulant activity. Ixodes scapularis feeding was significantly impaired when nymphs were fed on rabbits immunized with a cocktail of rP8, rP19 and rP23, a hall mark of tick-immunity. These studies also suggest that these antigens may serve as potential vaccine candidates to thwart tick feeding.

  17. Analysis of antibodies to newly described Plasmodium falciparum merozoite antigens supports MSPDBL2 as a predicted target of naturally acquired immunity.

    Science.gov (United States)

    Tetteh, Kevin K A; Osier, Faith H A; Salanti, Ali; Kamuyu, Gathoni; Drought, Laura; Failly, Marilyne; Martin, Christophe; Marsh, Kevin; Conway, David J

    2013-10-01

    Prospective studies continue to identify malaria parasite genes with particular patterns of polymorphism which indicate they may be under immune selection, and the encoded proteins require investigation. Sixteen new recombinant protein reagents were designed to characterize three such polymorphic proteins expressed in Plasmodium falciparum schizonts and merozoites: MSPDBL1 (also termed MSP3.4) and MSPDBL2 (MSP3.8), which possess Duffy binding-like (DBL) domains, and SURFIN4.2, encoded by a member of the surface-associated interspersed (surf) multigene family. After testing the antigenicities of these reagents by murine immunization and parasite immunofluorescence, we analyzed naturally acquired antibody responses to the antigens in two cohorts in coastal Kenya in which the parasite was endemic (Chonyi [n = 497] and Ngerenya [n = 461]). As expected, the prevalence and levels of serum antibodies increased with age. We then investigated correlations with subsequent risk of clinical malaria among children <11 years of age during 6 months follow-up surveillance. Antibodies to the polymorphic central region of MSPDBL2 were associated with reduced risk of malaria in both cohorts, with statistical significance remaining for the 3D7 allelic type after adjustment for individuals' ages in years and antibody reactivity to whole-schizont extract (Chonyi, risk ratio, 0.51, and 95% confidence interval [CI], 0.28 to 0.93; Ngerenya, risk ratio, 0.38, and 95% CI, 0.18 to 0.82). For the MSPDBL1 Palo Alto allelic-type antigen, there was a protective association in one cohort (Ngerenya, risk ratio, 0.53, and 95% CI, 0.32 to 0.89), whereas the other antigens showed no protective associations after adjustment. These findings support the prediction that antibodies to the polymorphic region of MSPDBL2 contribute to protective immunity.

  18. Engineering tolerance using biomaterials to target and control antigen presenting cells.

    Science.gov (United States)

    Tostanoski, Lisa H; Gosselin, Emily A; Jewell, Christopher M

    2016-05-01

    Autoimmune diseases occur when cells of the adaptive immune system incorrectly recognize and attack "self" tissues. Importantly, the proliferation and differentiation of these cells is triggered and controlled by interactions with antigen presenting cells (APCs), such as dendritic cells. Thus, modulating the signals transduced by APCs (e.g., cytokines, costimulatory surface proteins) has emerged as a promising strategy to promote tolerance for diseases such as multiple sclerosis, type 1 diabetes, and lupus. However, many approaches have been hindered by non-specific activity of immunosuppressive or immunoregulatory cues, following systemic administration of soluble factors via traditional injections routes (e.g., subcutaneous, intravenous). Biomaterials offer a unique opportunity to control the delivery of tolerogenic signals in vivo via properties such as controlled particle size, tunable release kinetics, and co-delivery of multiple classes of cargo. In this review, we highlight recent reports that exploit these properties of biomaterials to target APCs and promote tolerance via three strategies, i) passive or active targeting of particulate carriers to APCs, ii) biomaterial-mediated control over antigen localization and processing, and iii) targeted delivery of encapsulated or adsorbed immunomodulatory signals. These reports represent exciting advances toward the goal of more effective therapies for autoimmune diseases, without the broad suppressive effects associated with current clinically-approved therapies.

  19. Clay Nanoparticles Elicit Long-Term Immune Responses by Forming Biodegradable Depots for Sustained Antigen Stimulation.

    Science.gov (United States)

    Chen, Weiyu; Zuo, Huali; Li, Bei; Duan, Chengcheng; Rolfe, Barbara; Zhang, Bing; Mahony, Timothy J; Xu, Zhi Ping

    2018-05-01

    Nanomaterials have been widely tested as new generation vaccine adjuvants, but few evoke efficient immunoreactions. Clay nanoparticles, for example, layered double hydroxide (LDH) and hectorite (HEC) nanoparticles, have shown their potent adjuvanticity in generating effective and durable immune responses. However, the mechanism by which clay nanoadjuvants stimulate the immune system is not well understood. Here, it is demonstrated that LDH and HEC-antigen complexes form loose agglomerates in culture medium/serum. They also form nodules with loose structures in tissue after subcutaneous injection, where they act as a depot for up to 35 d. More importantly, clay nanoparticles actively and continuously recruit immune cells into the depot for up to one month, and stimulate stronger immune responses than FDA-approved adjuvants, Alum and QuilA. Sustained antigen release is also observed in clay nanoparticle depots, with 50-60% antigen released after 35 d. In contrast, Alum-antigen complexes show minimal antigen release from the depot. Importantly, LDH and HEC are more effective than QuilA and Alum in promoting memory T-cell proliferation. These findings suggest that both clay nanoadjuvants can serve as active vaccine platforms for sustained and potent immune responses. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Tracking targeted bimodal nanovaccines: immune responses and routing in cells, tissue, and whole organism.

    Science.gov (United States)

    Cruz, Luis J; Tacken, Paul J; Zeelenberg, Ingrid S; Srinivas, Mangala; Bonetto, Fernando; Weigelin, Bettina; Eich, Christina; de Vries, I Jolanda; Figdor, Carl G

    2014-12-01

    Dendritic cells (DCs) are the most potent antigen-presenting cells (APCs), involved in the induction of immunity and currently exploited for antitumor immunotherapies. An optimized noninvasive imaging modality capable of determining and quantifying DC-targeted nanoparticle (NP) trajectories could provide valuable information regarding therapeutic vaccine outcome. Here, targeted poly(d,l-lactide-co-glycolide) nanoparticles (PLGA NPs) recognizing DC receptors were equipped with superparamagnetic iron oxide particles (SPIO) or gold nanoparticles with fluorescently labeled antigen. The fluorescent label allowed for rapid analysis and quantification of DC-specific uptake of targeted PLGA NPs in comparison to uptake by other cells. Transmission electron microscopy (TEM) showed that a fraction of the encapsulated antigen reached the lysosomal compartment of DCs, where SPIO and gold were already partially released. However, part of the PLGA NPs localized within the cytoplasm, as confirmed by confocal microscopy. DCs targeted with NPs carrying SPIO or fluorescent antigen were detected within lymph nodes as early as 1 h after injection by magnetic resonance imaging (MRI). Despite the fact that targeting did not markedly affect PLGA NP biodistribution on organism and tissue level, it increased delivery of NPs to DCs residing in peripheral lymph nodes and resulted in enhanced T cell proliferation. In conclusion, two imaging agents within a single carrier allows tracking of targeted PLGA NPs at the subcellular, cellular, and organismal levels, thereby facilitating the rational design of in vivo targeted vaccination strategies.

  1. Recent Advances in Targeting CD8 T-Cell Immunity for More Effective Cancer Immunotherapy

    Directory of Open Access Journals (Sweden)

    Aurélie Durgeau

    2018-01-01

    Full Text Available Recent advances in cancer treatment have emerged from new immunotherapies targeting T-cell inhibitory receptors, including cytotoxic T-lymphocyte associated antigen (CTLA-4 and programmed cell death (PD-1. In this context, anti-CTLA-4 and anti-PD-1 monoclonal antibodies have demonstrated survival benefits in numerous cancers, including melanoma and non-small-cell lung carcinoma. PD-1-expressing CD8+ T lymphocytes appear to play a major role in the response to these immune checkpoint inhibitors (ICI. Cytotoxic T lymphocytes (CTL eliminate malignant cells through recognition by the T-cell receptor (TCR of specific antigenic peptides presented on the surface of cancer cells by major histocompatibility complex class I/beta-2-microglobulin complexes, and through killing of target cells, mainly by releasing the content of secretory lysosomes containing perforin and granzyme B. T-cell adhesion molecules and, in particular, lymphocyte-function-associated antigen-1 and CD103 integrins, and their cognate ligands, respectively, intercellular adhesion molecule 1 and E-cadherin, on target cells, are involved in strengthening the interaction between CTL and tumor cells. Tumor-specific CTL have been isolated from tumor-infiltrating lymphocytes and peripheral blood lymphocytes (PBL of patients with varied cancers. TCRβ-chain gene usage indicated that CTL identified in vitro selectively expanded in vivo at the tumor site compared to autologous PBL. Moreover, functional studies indicated that these CTL mediate human leukocyte antigen class I-restricted cytotoxic activity toward autologous tumor cells. Several of them recognize truly tumor-specific antigens encoded by mutated genes, also known as neoantigens, which likely play a key role in antitumor CD8 T-cell immunity. Accordingly, it has been shown that the presence of T lymphocytes directed toward tumor neoantigens is associated with patient response to immunotherapies, including ICI, adoptive cell transfer

  2. Immune activation by casein dietary antigens in bipolar disorder

    NARCIS (Netherlands)

    Severance, E.G.; Dupont, D.; Dickerson, F.B.; Stallings, C.R.; Origoni, A.E.; Krivogorsky, B.; Yang, S.; Haasnoot, W.; Yolken, R.H.

    2010-01-01

    Objectives: Inflammation and other immune processes are increasingly linked to psychiatric diseases. Antigenic triggers specific to bipolar disorder are not yet defined. We tested whether antibodies to bovine milk caseins were associated with bipolar disorder, and whether patients recognized

  3. Skin Immunization Obviates Alcohol-Related Immune Dysfunction

    Directory of Open Access Journals (Sweden)

    Rhonda M. Brand

    2015-11-01

    Full Text Available Alcoholics suffer from immune dysfunction that can impede vaccine efficacy. If ethanol (EtOH-induced immune impairment is in part a result of direct exposure of immune cells to EtOH, then reduced levels of exposure could result in less immune dysfunction. As alcohol ingestion results in lower alcohol levels in skin than blood, we hypothesized that the skin immune network may be relatively preserved, enabling skin-targeted immunizations to obviate the immune inhibitory effects of alcohol consumption on conventional vaccines. We employed the two most common chronic EtOH mouse feeding models, the liver-damaging Lieber-DeCarli (LD and liver-sparing Meadows-Cook (MC diets, to examine the roles of EtOH and/or EtOH-induced liver dysfunction on alcohol related immunosuppression. Pair-fed mice were immunized against the model antigen ovalbumin (OVA by DNA immunization or against flu by administering the protein-based influenza vaccine either systemically (IV, IM, directly to liver (hydrodynamic, or cutaneously (biolistic, ID. We measured resulting tissue EtOH levels, liver stress, regulatory T cell (Treg, and myeloid-derived suppressor cell (MDSC populations. We compared immune responsiveness by measuring delayed-type hypersensitivity (DTH, antigen-specific cytotoxic T lymphocyte (CTL, and antibody induction as a function of delivery route and feeding model. We found that, as expected, and independent of the feeding model, EtOH ingestion inhibits DTH, CTL lysis, and antigen-specific total IgG induced by traditional systemic vaccines. On the other hand, skin-targeted vaccines were equally immunogenic in alcohol-exposed and non-exposed subjects, suggesting that cutaneous immunization may result in more efficacious vaccination in alcohol-ingesting subjects.

  4. Antigenic characterization of small, round-structured viruses by immune electron microscopy.

    OpenAIRE

    Okada, S; Sekine, S; Ando, T; Hayashi, Y; Murao, M; Yabuuchi, K; Miki, T; Ohashi, M

    1990-01-01

    Small, round-structured viruses (SRSVs) detected from nonbacterial gastroenteritis outbreaks in Tokyo and Saitama Prefecture, Japan, during the period from 1977 to 1988 were tentatively classified into nine antigenic patterns from SRSV-1 (S-1) to SRSV-9 (S-9) by cross-immune electron microscopy (IEM). S-1 and S-2 appeared pattern specific, while S-3 to S-9, distinguishable from each other in their reactivity, appeared somewhat antigenically related. Their antigenic relatedness to the Norwal, ...

  5. Adoptive transfer of natural antibodies to non-immunized chickens affects subsequent antigen-specific humoral and cellular immune responses

    NARCIS (Netherlands)

    Lammers, A.; Klomp, M.E.V.; Nieuwland, M.G.B.; Savelkoul, H.F.J.; Parmentier, H.K.

    2004-01-01

    To determine a regulatory function of natural antibodies in the immune response of chickens, pooled plasma obtained from non-immunized (naive) 15 months old hens was subjected to keyhole limpet hemocyanin (KLH) antigen-affinity chromatography. Purified KLH-binding antibodies were adoptively

  6. Characterizing complex polysera produced by antigen-specific immunization through the use of affinity-selected mimotopes.

    Directory of Open Access Journals (Sweden)

    Galina Denisova

    Full Text Available BACKGROUND: Antigen-based (as opposed to whole organism vaccines are actively being pursued for numerous indications. Even though different formulations may produce similar levels of total antigen-specific antibody, the composition of the antibody response can be quite distinct resulting in different levels of therapeutic activity. METHODOLOGY/PRINCIPAL FINDINGS: Using plasmid-based immunization against the proto-oncogene HER-2 as a model, we have demonstrated that affinity-selected epitope mimetics (mimotopes can provide a defined signature of a polyclonal antibody response. Further, using novel computer algorithms that we have developed, these mimotopes can be used to predict epitope targets. CONCLUSIONS/SIGNIFICANCE: By combining our novel strategy with existing methods of epitope prediction based on physical properties of an individual protein, we believe that this method offers a robust method for characterizing the breadth of epitope-specificity within a specific polyserum. This strategy is useful as a tool for monitoring immunity following vaccination and can also be used to define relevant epitopes for the creation of novel vaccines.

  7. T Lymphocyte-Endothelial Interactions: Emerging Understanding of Trafficking and Antigen-Specific Immunity

    Directory of Open Access Journals (Sweden)

    Christopher Vincent Carman

    2015-11-01

    Full Text Available Antigen-specific immunity requires regulated trafficking of T cells in and out of diverse tissues in order to orchestrate lymphocyte development, immune surveillance, responses and memory. The endothelium serves as a unique barrier, as well as a sentinel, between the blood and the tissues and as such it plays an essential locally tuned role in regulating T cell migration and information exchange. While it is well established that chemoattractants and adhesion molecules are major determinants of T cell trafficking, emerging studies have now enumerated a large number of molecular players as well as a range of discrete cellular remodeling activities (e.g. transmigratory cups and invadosome-like protrusions, IPLs that participate in directed migration and pathfinding by T cells. In addition to providing trafficking cues, intimate cell-cell interaction between lymphocytes and endothelial cells provide instruction to T cells that influence their activation and differentiation states. Perhaps the most intriguing and underappreciated of these ‘sentinel’ roles is the ability of the endothelium to act as a non-hematopoietic ‘semi-professional’ antigen-presenting cell. Close contacts between circulating T cells and antigen-presenting endothelium may play unique non-redundant roles in shaping adaptive immune responses within the periphery. A better understanding of the mechanisms directing T cell trafficking and the antigen-presenting role of the endothelium may not only increase our knowledge of the adaptive immune response but also empower the utility of emerging immunomodulatory therapeutics.

  8. [Humoral immune diseases: Cutaneous vasculitis and auto-immune bullous dermatoses].

    Science.gov (United States)

    Wechsler, Janine

    2018-02-01

    Humoral immunity is the cause of multiple diseases related to antibodies (IgA, IgG, IgM) produced by the patient. Two groups of diseases are identified. The first group is related to circulating antigen-antibody complexes. The antigens are various. They are often unknown. These immune complexes cause a vascular inflammation due to the complement fixation. Consequently, this group is dominated by inflammatory vasculitis. In the second group, the pathology is due to the fixation in situ of antibodies to a target antigen of the skin that is no more recognized by the patient. This group is represented by the auto-immune bullous dermatoses. Copyright © 2017. Published by Elsevier Masson SAS.

  9. Targeted Delivery of Toxoplasma gondii Antigens to Dendritic Cells Promote Immunogenicity and Protective Efficiency against Toxoplasmosis

    Directory of Open Access Journals (Sweden)

    Zineb Lakhrif

    2018-02-01

    Full Text Available Toxoplasmosis is a major public health problem and the development of a human vaccine is of high priority. Efficient vaccination against Toxoplasma gondii requires both a mucosal and systemic Th1 immune response. Moreover, dendritic cells play a critical role in orchestrating the innate immune functions and driving specific adaptive immunity to T. gondii. In this study, we explore an original vaccination strategy that combines administration via mucosal and systemic routes of fusion proteins able to target the major T. gondii surface antigen SAG1 to DCs using an antibody fragment single-chain fragment variable (scFv directed against DEC205 endocytic receptor. Our results show that SAG1 targeting to DCs by scFv via intranasal and subcutaneous administration improved protection against chronic T. gondii infection. A marked reduction in brain parasite burden is observed when compared with the intranasal or the subcutaneous route alone. DC targeting improved both local and systemic humoral and cellular immune responses and potentiated more specifically the Th1 response profile by more efficient production of IFN-γ, interleukin-2, IgG2a, and nasal IgA. This study provides evidence of the potential of DC targeting for the development of new vaccines against a range of Apicomplexa parasites.

  10. CD8(+)NKT-like cells regulate the immune response by killing antigen-bearing DCs.

    Science.gov (United States)

    Wang, Chao; Liu, Xi; Li, Zhengyuan; Chai, Yijie; Jiang, Yunfeng; Wang, Qian; Ji, Yewei; Zhu, Zhongli; Wan, Ying; Yuan, Zhenglong; Chang, Zhijie; Zhang, Minghui

    2015-09-15

    CD1d-dependent NKT cells have been extensively studied; however, the function of CD8(+)NKT-like cells, which are CD1d-independent T cells with NK markers, remains unknown. Here, we report that CD1d-independent CD8(+)NKT-like cells, which express both T cell markers (TCRβ and CD3) and NK cell receptors (NK1.1, CD49b and NKG2D), are activated and significantly expanded in mice immunized with GFP-expressing dendritic cells. Distinct from CD1d-dependent NKT cells, CD8(+)NKT-like cells possess a diverse repertoire of TCRs and secrete high levels of IFN-gamma but not IL-4. CD8(+)NKT-like cell development is normal in CD1d(-/-) mice, which suggests that CD8(+)NKT-like cells undergo a unique development pathway that differs from iNKT cells. Further functional analyses show that CD8(+)NKT-like cells suppress T-cell responses through elimination of dendritic cells in an antigen-specific manner. Adoptive transfer of antigen-specific CD8(+)NKT-like cells into RIP-OVA mice prevented subsequent development of diabetes in the animals induced by activated OT-I CD8 T cells. Our study suggests that CD8(+)NKT-like cells can function as antigen-specific suppressive cells to regulate the immune response through killing antigen-bearing DCs. Antigen-specific down regulation may provide an active and precise method for constraining an excessive immune response and avoiding bypass suppression of necessary immune responses to other antigens.

  11. CD8+NKT-like cells regulate the immune response by killing antigen-bearing DCs

    Science.gov (United States)

    Wang, Chao; Liu, Xi; Li, Zhengyuan; Chai, Yijie; Jiang, Yunfeng; Wang, Qian; Ji, Yewei; Zhu, Zhongli; Wan, Ying; Yuan, Zhenglong; Chang, Zhijie; Zhang, Minghui

    2015-01-01

    CD1d-dependent NKT cells have been extensively studied; however, the function of CD8+NKT-like cells, which are CD1d-independent T cells with NK markers, remains unknown. Here, we report that CD1d-independent CD8+NKT-like cells, which express both T cell markers (TCRβ and CD3) and NK cell receptors (NK1.1, CD49b and NKG2D), are activated and significantly expanded in mice immunized with GFP-expressing dendritic cells. Distinct from CD1d-dependent NKT cells, CD8+NKT-like cells possess a diverse repertoire of TCRs and secrete high levels of IFN-gamma but not IL-4. CD8+NKT-like cell development is normal in CD1d−/− mice, which suggests that CD8+NKT-like cells undergo a unique development pathway that differs from iNKT cells. Further functional analyses show that CD8+NKT-like cells suppress T-cell responses through elimination of dendritic cells in an antigen-specific manner. Adoptive transfer of antigen-specific CD8+NKT-like cells into RIP-OVA mice prevented subsequent development of diabetes in the animals induced by activated OT-I CD8 T cells. Our study suggests that CD8+NKT-like cells can function as antigen-specific suppressive cells to regulate the immune response through killing antigen-bearing DCs. Antigen-specific down regulation may provide an active and precise method for constraining an excessive immune response and avoiding bypass suppression of necessary immune responses to other antigens. PMID:26369936

  12. Virosomes for antigen and DNA delivery

    NARCIS (Netherlands)

    Daemen, T; de Mare, A; Bungener, L; de Jonge, J; Huckriede, A; Wilschut, J

    2005-01-01

    Specific targeting and delivery as well as the display of antigens on the surface of professional antigen-presenting cells (APCs) are key issues in the design and development of new-generation vaccines aimed at the induction of both humoral and cell-mediated immunity. Prophylactic vaccination

  13. Clostridium perfringens Antigens Recognized by Broiler Chickens Immune to Necrotic Enteritis▿

    OpenAIRE

    Kulkarni, R. R.; Parreira, V. R.; Sharif, S.; Prescott, J. F.

    2006-01-01

    Little is known about immunity to necrotic enteritis (NE) in chickens. A recent study of broiler chickens showed that protection against NE was associated with infection-immunization with virulent but not with avirulent Clostridium perfringens.In the current study, six secreted antigenic proteins unique to virulent C. perfringens that reacted to serum antibodies from immune birds were identified by mass spectrophotometry; three of these proteins are part of the VirR-VirS regulon.

  14. Host immunity in the protective response to nasal immunization with a pneumococcal antigen associated to live and heat-killed Lactobacillus casei.

    Science.gov (United States)

    Vintiñi, Elisa O; Medina, Marcela S

    2011-08-11

    At present, available pneumococcal vaccines have failed to eradicate infections caused by S. pneumoniae. Search for effective vaccine continues and some serotype independent pneumococcal proteins are considered as candidates for the design of new vaccines, especially a mucosal vaccine, since pneumococci enter the body through mucosal surfaces. Selection of the appropriate adjuvant is important for mucosal vaccines, and lactic acid bacteria (LAB) with immunostimulant properties are promissory candidates. In this work, we assessed the adjuvant effect of a probiotic strain, Lactobacillus casei (L. casei), when nasally administered with a pneumococcal antigen (pneumococcal protective protein A: PppA) for the prevention of pneumococcal infection. Adjuvanticity of both live (LcV) and heat-killed (LcM) was evaluated and humoral and cellular antigen-specific immune response was assessed in mucosal and systemic compartments. The potential mechanisms induced by nasal immunization were discussed. Nasal immunization of young mice with PppA+LcV and PppA+LcM induced anti-PppA IgA and IgG antibodies in mucosal and systemic compartments and levels of these specific antibodies remained high even at day 45 after the 3rd Immunization (3rd I). These results were correlated with IL-4 induction by the mixture of antigen plus LcV and LcM. Also, PppA+Lc (V and M) induced stimulation of Th1 and Th17 cells involved in the defence against pneumococci. The protection against pneumococcal respiratory challenge at day 30 after the 3rd I showed that PppA+LcV and PppA+LcM immunizations significantly reduced pathogen counts in nasal lavages while prventing their passage into lung and blood. Survival of mice immunized with the co-application of PppA plus LcV and LcM was significantly higher than in mice immunized with PppA alone and control mice when intraperitoneal challenge was performed. No significant differences between the treatments involving LcV and LcM were found. Live and heat-killed L

  15. Host immunity in the protective response to nasal immunization with a pneumococcal antigen associated to live and heat-killed Lactobacillus casei

    Directory of Open Access Journals (Sweden)

    Vintiñi Elisa O

    2011-08-01

    Full Text Available Abstract Background At present, available pneumococcal vaccines have failed to eradicate infections caused by S. pneumoniae. Search for effective vaccine continues and some serotype independent pneumococcal proteins are considered as candidates for the design of new vaccines, especially a mucosal vaccine, since pneumococci enter the body through mucosal surfaces. Selection of the appropriate adjuvant is important for mucosal vaccines, and lactic acid bacteria (LAB with immunostimulant properties are promissory candidates. In this work, we assessed the adjuvant effect of a probiotic strain, Lactobacillus casei (L. casei, when nasally administered with a pneumococcal antigen (pneumococcal protective protein A: PppA for the prevention of pneumococcal infection. Adjuvanticity of both live (LcV and heat-killed (LcM was evaluated and humoral and cellular antigen-specific immune response was assessed in mucosal and systemic compartments. The potential mechanisms induced by nasal immunization were discussed. Results Nasal immunization of young mice with PppA+LcV and PppA+LcM induced anti-PppA IgA and IgG antibodies in mucosal and systemic compartments and levels of these specific antibodies remained high even at day 45 after the 3rd Immunization (3rd I. These results were correlated with IL-4 induction by the mixture of antigen plus LcV and LcM. Also, PppA+Lc (V and M induced stimulation of Th1 and Th17 cells involved in the defence against pneumococci. The protection against pneumococcal respiratory challenge at day 30 after the 3rd I showed that PppA+LcV and PppA+LcM immunizations significantly reduced pathogen counts in nasal lavages while prventing their passage into lung and blood. Survival of mice immunized with the co-application of PppA plus LcV and LcM was significantly higher than in mice immunized with PppA alone and control mice when intraperitoneal challenge was performed. No significant differences between the treatments involving LcV and

  16. Poly-functional and long-lasting anticancer immune response elicited by a safe attenuated Pseudomonas aeruginosa vector for antigens delivery

    Directory of Open Access Journals (Sweden)

    Xavier Chauchet

    2016-01-01

    Full Text Available Live-attenuated bacterial vectors for antigens delivery have aroused growing interest in the field of cancer immunotherapy. Their potency to stimulate innate immunity and to promote intracellular antigen delivery into antigen-presenting cells could be exploited to elicit a strong and specific cellular immune response against tumor cells. We previously described genetically-modified and attenuated Pseudomonas aeruginosa vectors able to deliver in vivo protein antigens into antigen-presenting cells, through Type 3 secretion system of the bacteria. Using this approach, we managed to protect immunized mice against aggressive B16 melanoma development in both a prophylactic and therapeutic setting. In this study, we further investigated the antigen-specific CD8+ T cell response, in terms of phenotypic and functional aspects, obtained after immunizations with a killed but metabolically active P. aeruginosa attenuated vector. We demonstrated that P. aeruginosa vaccine induces a highly functional pool of antigen-specific CD8+ T cell able to infiltrate the tumor. Furthermore, multiple immunizations allowed the development of a long-lasting immune response, represented by a pool of predominantly effector memory cells which protected mice against late tumor challenge. Overall, killed but metabolically active P. aeruginosa vector is a safe and promising approach for active and specific antitumor immunotherapy.

  17. Dendritic cell targeted chitosan nanoparticles for nasal DNA immunization against SARS CoV nucleocapsid protein.

    Science.gov (United States)

    Raghuwanshi, Dharmendra; Mishra, Vivek; Das, Dipankar; Kaur, Kamaljit; Suresh, Mavanur R

    2012-04-02

    This work investigates the formulation and in vivo efficacy of dendritic cell (DC) targeted plasmid DNA loaded biotinylated chitosan nanoparticles for nasal immunization against nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) as antigen. The induction of antigen-specific mucosal and systemic immune response at the site of virus entry is a major challenge for vaccine design. Here, we designed a strategy for noninvasive receptor mediated gene delivery to nasal resident DCs. The pDNA loaded biotinylated chitosan nanoparticles were prepared using a complex coacervation process and characterized for size, shape, surface charge, plasmid DNA loading and protection against nuclease digestion. The pDNA loaded biotinylated chitosan nanoparticles were targeted with bifunctional fusion protein (bfFp) vector for achieving DC selective targeting. The bfFp is a recombinant fusion protein consisting of truncated core-streptavidin fused with anti-DEC-205 single chain antibody (scFv). The core-streptavidin arm of fusion protein binds with biotinylated nanoparticles, while anti-DEC-205 scFv imparts targeting specificity to DC DEC-205 receptor. We demonstrate that intranasal administration of bfFp targeted formulations along with anti-CD40 DC maturation stimuli enhanced magnitude of mucosal IgA as well as systemic IgG against N protein. The strategy led to the detection of augmented levels of N protein specific systemic IgG and nasal IgA antibodies. However, following intranasal delivery of naked pDNA no mucosal and systemic immune responses were detected. A parallel comparison of targeted formulations using intramuscular and intranasal routes showed that the intramuscular route is superior for induction of systemic IgG responses compared with the intranasal route. Our results suggest that targeted pDNA delivery through a noninvasive intranasal route can be a strategy for designing low-dose vaccines.

  18. Post-translational regulation of Foxp3 : identification of novel molecular targets for immune modulation

    NARCIS (Netherlands)

    van Loosdregt, J.

    2011-01-01

    Maintenance of immune homeostasis is a complex process allowing the immune system to be both aggressive enough to eradicate cells that express foreign antigens, and yet provide sensitivity to tolerate cells expressing self antigens. Key modulators allowing tolerance of host antigens, thereby

  19. The activation of the adaptive immune system: cross-talk between antigen-presenting cells, T cells and B cells.

    Science.gov (United States)

    den Haan, Joke M M; Arens, Ramon; van Zelm, Menno C

    2014-12-01

    The adaptive immune system consists of T and B cells that express clonally distributed antigen receptors. To achieve functional adaptive immune responses, antigen-specific T cell populations are stimulated by professional antigen-presenting cells like dendritic cells (DCs), which provide crucial stimulatory signals for efficient expansion and development of effector functions. Antigen-specific B cells receive costimulatory signals from helper T cells to stimulate affinity maturation and isotype switching. Here we elaborate on the interactions between DCs, T cells and B cells, and on the important signals for efficient induction of adaptive immune responses. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Estradiol-induced vaginal mucus inhibits antigen penetration and CD8(+) T cell priming in response to intravaginal immunization.

    Science.gov (United States)

    Seavey, Matthew M; Mosmann, Tim R

    2009-04-14

    Although vaginal immunization has been explored as a strategy to induce mucosal immunity in the female reproductive tract, this site displays unique immunological features that probably evolved to inhibit anti-paternal T cell responses after insemination to allow successful pregnancy. We previously demonstrated that estradiol, which induces an estrus-like state, prevented CD8(+) T cell priming during intravaginal immunization of mice. We now show that estradiol prevented antigen loading of vaginal antigen presenting cells (APCs) after intravaginal immunization. Histological examination confirmed that estradiol prevented penetration of peptide antigen into the vaginal wall. Removal of the estradiol-induced mucus barrier by mucinase partially restored antigen loading of vaginal APC and CD8(+) T cell proliferation in vivo. The estradiol-induced mucus barrier may thus prevent exposure to antigens delivered intravaginally, supplementing additional estradiol-dependent mechanism(s) that inhibit CD8(+) T cell priming after insemination or vaginal vaccination.

  1. Estradiol-induced vaginal mucus inhibits antigen penetration and CD8+ T cell priming in response to intravaginal immunization

    Science.gov (United States)

    Seavey, Matthew M.; Mosmann, Tim R.

    2010-01-01

    Although vaginal immunization has been explored as a strategy to induce mucosal immunity in the female reproductive tract, this site displays unique immunological features that probably evolved to inhibit anti-paternal T cell responses after insemination to allow successful pregnancy. We previously demonstrated that estradiol, which induces an estrus-like state, prevented CD8+ T cell priming during intravaginal immunization of mice. We now show that estradiol prevented antigen loading of vaginal antigen presenting cells (APC) after intravaginal immunization. Histological examination confirmed that estradiol prevented penetration of peptide antigen into the vaginal wall. Removal of the estradiol-induced mucus barrier by mucinase partially restored antigen loading of vaginal APC and CD8+ T cell proliferation in vivo. The estradiol-induced mucus barrier may thus prevent exposure to antigens delivered intravaginally, supplementing additional estradiol-dependent mechanism(s) that inhibit CD8+ T cell priming after insemination or vaginal vaccination. PMID:19428849

  2. IMMUNITY STATE IN THE OFFSPRING OF RATS EXPOSED ANTIGENS TOXOPLASMA GONDII

    Directory of Open Access Journals (Sweden)

    T. F. Sokolova

    2014-01-01

    Full Text Available Today the questions about possibility of development disturbances in the immune system of the fetus and the newborn in chronic toxoplasmosis are poorly understood. Aim of research: to detect immunological disturbances in the offspring of rats which have been administered antigens T. gondii.Two series of experiments was performed. In these experiments white female Wistar rats in the III trimester of pregnancy have been administered corpuscular antigen T. gondii. The 60 days-old offspring of these rats have been included in study group of 137 animals. CD3+ cells count was performed in peripherical blood and standard suspension of splenocytesrats offspring. Peripherical blood cells count was performed in the blood of the rats offspring. In the second experiment rats offspring have been administered sheep erythrocytes in 5 days, before euthanasia. In spleen of this rats antigen-produced cells was counted.In control group was included 118 animals, which was born from white female Wistar rats have been administered 0,9% NaCl solution. CD3+ cells was detected in Cytomics FC500 flow cytometry analyzer (Beckman Coulter,USA by use rats origne-specifed monoclonal antibodies Anti-Rat CD3-FITC (Beckman Coulter,USA. Hematological parameters was assessed by use hematological analyzer Excell-22 (USA.We observed, that CD3+ lymphocytes and antigen-produced cells was decreased in test group (degress of decrease CD3+ cells was 17,2%; р = 0,003 in spleen vs. control group, degress of decrease antigen-produced cells was 27,3%; р = 0,03 vs. control group. Number of leukocytes was increased in in test group (34,5%; р = 0,009 vs. control group. Power and strength correlation pleiades between studied blood and spenal markers were higher in in test group vs. control group (∑Gi = 16; ∑Di = 4,38 vs. ∑Gi = 13; ∑Di = 2,28. This phenomenon is probably due to the development adaptive reactions disruption in the immune system and development

  3. Enhancement of Skin Permeation and Skin Immunization of Ovalbumin Antigen via Microneedles.

    Science.gov (United States)

    Pamornpathomkul, Boonnada; Rojanarata, Theerasak; Opanasopit, Praneet; Ngawhirunpat, Tanasait

    2017-10-01

    The purpose of this study was to evaluate the use of different types of microneedles and doses of ovalbumin antigen for in vitro skin permeation and in vivo immunization. In vitro skin permeation experiments and confocal laser scanning microscopy revealed that hollow microneedles had a superior enhancing effect on skin permeation compared with a solid microneedle patch and untreated skin by efficiently delivering ovalbumin-fluorescein conjugate into the deep skin layers. The flux and cumulative amount of ovalbumin-fluorescein conjugate at 8 h after administering with various conditions could be ranked as follows: hollow MN; high dose > medium dose > low dose > MN patch; high dose > medium dose > low dose > untreated skin; high dose > medium dose > low dose > without ovalbumin-fluorescein conjugate. As the dose of ovalbumin-fluorescein conjugate was increased to 500 μg, the antigen accumulated in the skin to a greater extent, as evidenced by the increasing green fluorescence intensity. When the hollow microneedle was used for the delivery of ovalbumin into the skin of mice, it was capable of inducing a stronger immunoglobulin G immune response than conventional subcutaneous injection at the same antigen dose. Immunoglobulin G levels in the hollow MN group were 5.7, 11.6, and 13.3 times higher than those of the subcutaneous injection group for low, medium, and high doses, respectively. Furthermore, the mice immunized using the hollow microneedle showed no signs of skin infection or pinpoint bleeding. The results suggest that the hollow MN is an efficient device for delivering the optimal dose of antigen via the skin for successful immunization.

  4. Perillyl alcohol suppresses antigen-induced immune responses in the lung

    International Nuclear Information System (INIS)

    Imamura, Mitsuru; Sasaki, Oh; Okunishi, Katsuhide; Nakagome, Kazuyuki; Harada, Hiroaki; Kawahata, Kimito; Tanaka, Ryoichi; Yamamoto, Kazuhiko; Dohi, Makoto

    2014-01-01

    Highlights: •Perillyl alcohol (POH) is an isoprenoid which inhibits the mevalonate pathway. •We examined whether POH suppresses immune responses with a mouse model of asthma. •POH treatment during sensitization suppressed Ag-induced priming of CD4 + T cells. •POH suppressed airway eosinophila and cytokine production in thoracic lymph nodes. -- Abstract: Perillyl alcohol (POH) is an isoprenoid which inhibits farnesyl transferase and geranylgeranyl transferase, key enzymes that induce conformational and functional changes in small G proteins to conduct signal production for cell proliferation. Thus, it has been tried for the treatment of cancers. However, although it affects the proliferation of immunocytes, its influence on immune responses has been examined in only a few studies. Notably, its effect on antigen-induced immune responses has not been studied. In this study, we examined whether POH suppresses Ag-induced immune responses with a mouse model of allergic airway inflammation. POH treatment of sensitized mice suppressed proliferation and cytokine production in Ag-stimulated spleen cells or CD4 + T cells. Further, sensitized mice received aerosolized OVA to induce allergic airway inflammation, and some mice received POH treatment. POH significantly suppressed indicators of allergic airway inflammation such as airway eosinophilia. Cytokine production in thoracic lymph nodes was also significantly suppressed. These results demonstrate that POH suppresses antigen-induced immune responses in the lung. Considering that it exists naturally, POH could be a novel preventive or therapeutic option for immunologic lung disorders such as asthma with minimal side effects

  5. 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...

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

    Science.gov (United States)

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

    2014-10-07

    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.

  7. Humoral immunity provides resident intestinal eosinophils access to luminal antigen via eosinophil-expressed low affinity Fc gamma receptors

    Science.gov (United States)

    Smith, Kalmia M.; Rahman, Raiann S.; Spencer, Lisa A.

    2016-01-01

    Eosinophils are native to the healthy gastrointestinal tract, and are associated with inflammatory diseases likely triggered by exposure to food allergens (e.g. food allergies and eosinophilic gastrointestinal disorders). In models of allergic respiratory diseases and in vitro studies, direct antigen engagement elicits eosinophil effector functions including degranulation and antigen presentation. However, it was not known whether intestinal tissue eosinophils that are separated from luminal food antigens by a columnar epithelium might similarly engage food antigens. Using an intestinal ligated loop model in mice, here we determined that resident intestinal eosinophils acquire antigen from the lumen of antigen-sensitized but not naïve mice in vivo. Antigen acquisition was immunoglobulin-dependent; intestinal eosinophils were unable to acquire antigen in sensitized immunoglobulin-deficient mice, and passive immunization with immune serum or antigen-specific IgG was sufficient to enable intestinal eosinophils in otherwise naïve mice to acquire antigen in vivo. Intestinal eosinophils expressed low affinity IgG receptors, and the activating receptor FcγRIII was necessary for immunoglobulin-mediated acquisition of antigens by isolated intestinal eosinophils in vitro. Our combined data suggest that intestinal eosinophils acquire lumen-derived food antigens in sensitized mice via FcγRIII antigen focusing, and may therefore participate in antigen-driven secondary immune responses to oral antigens. PMID:27683752

  8. Induction of Robust Immune Responses in Swine by Using a Cocktail of Adenovirus-Vectored African Swine Fever Virus Antigens.

    Science.gov (United States)

    Lokhandwala, Shehnaz; Waghela, Suryakant D; Bray, Jocelyn; Martin, Cameron L; Sangewar, Neha; Charendoff, Chloe; Shetti, Rashmi; Ashley, Clay; Chen, Chang-Hsin; Berghman, Luc R; Mwangi, Duncan; Dominowski, Paul J; Foss, Dennis L; Rai, Sharath; Vora, Shaunak; Gabbert, Lindsay; Burrage, Thomas G; Brake, David; Neilan, John; Mwangi, Waithaka

    2016-11-01

    The African swine fever virus (ASFV) causes a fatal hemorrhagic disease in domestic swine, and at present no treatment or vaccine is available. Natural and gene-deleted, live attenuated strains protect against closely related virulent strains; however, they are yet to be deployed and evaluated in the field to rule out chronic persistence and a potential for reversion to virulence. Previous studies suggest that antibodies play a role in protection, but induction of cytotoxic T lymphocytes (CTLs) could be the key to complete protection. Hence, generation of an efficacious subunit vaccine depends on identification of CTL targets along with a suitable delivery method that will elicit effector CTLs capable of eliminating ASFV-infected host cells and confer long-term protection. To this end, we evaluated the safety and immunogenicity of an adenovirus-vectored ASFV (Ad-ASFV) multiantigen cocktail formulated in two different adjuvants and at two immunizing doses in swine. Immunization with the cocktail rapidly induced unprecedented ASFV antigen-specific antibody and cellular immune responses against all of the antigens. The robust antibody responses underwent rapid isotype switching within 1 week postpriming, steadily increased over a 2-month period, and underwent rapid recall upon boost. Importantly, the primed antibodies strongly recognized the parental ASFV (Georgia 2007/1) by indirect fluorescence antibody (IFA) assay and Western blotting. Significant antigen-specific gamma interferon-positive (IFN-γ + ) responses were detected postpriming and postboosting. Furthermore, this study is the first to demonstrate induction of ASFV antigen-specific CTL responses in commercial swine using Ad-ASFV multiantigens. The relevance of the induced immune responses in regard to protection needs to be evaluated in a challenge study. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  9. Host range, immunity and antigenic properties of lambdoid coliphage HK97.

    Science.gov (United States)

    Dhillon, E K; Dhillon, T S; Lai, A N; Linn, S

    1980-09-01

    Temperate coliphage HK97 was isolated from pig dung. Although HK97 is antigenically unrelated to coliphage lambda, it has similar morphology, host range and immunity properties, and can recombine with it.

  10. Strategy for eliciting antigen-specific CD8+ T cell-mediated immune response against a cryptic CTL epitope of merkel cell polyomavirus large T antigen

    Directory of Open Access Journals (Sweden)

    Gomez Bianca P

    2012-10-01

    Full Text Available Abstract Background Merkel cell carcinoma (MCC is a relatively new addition to the expanding category of oncovirus-induced cancers. Although still comparably rare, the number of cases has risen dramatically in recent years. Further complicating this trend is that MCC is an extremely aggressive neoplasm with poor patient prognosis and limited treatment options for advanced disease. The causative agent of MCC has been identified as the merkel cell polyomavirus (MCPyV. The MCPyV-encoded large T (LT antigen is an oncoprotein that is theorized to be essential for virus-mediated tumorigenesis and is therefore, an excellent MCC antigen for the generation of antitumor immune responses. As a foreign antigen, the LT oncoprotein avoids the obstacle of immune tolerance, which normally impedes the development of antitumor immunity. Ergo, it is an excellent target for anti-MCC immunotherapy. Since tumor-specific CD8+ T cells lead to better prognosis for MCC and numerous other cancers, we have generated a DNA vaccine that is capable of eliciting LT-specific CD8+ T cells. The DNA vaccine (pcDNA3-CRT/LT encodes the LT antigen linked to a damage-associated molecular pattern, calreticulin (CRT, as it has been demonstrated that the linkage of CRT to antigens promotes the induction of antigen-specific CD8+ T cells. Results The present study shows that DNA vaccine-induced generation of LT-specific CD8+ T cells is augmented by linking CRT to the LT antigen. This is relevant since the therapeutic effects of the pcDNA3-CRT/LT DNA vaccine is mediated by LT-specific CD8+ T cells. Mice vaccinated with the DNA vaccine produced demonstrably more LT-specific CD8+ T cells. The DNA vaccine was also able to confer LT-specific CD8+ T cell-mediated protective and therapeutic effects to prolong the survival of mice with LT-expressing tumors. In the interest of determining the LT epitope which most MCC-specific CD8+ T cells recognize, we identified the amino acid sequence of the

  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.

    2014-01-01

    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

  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

    2014-09-08

    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.

  13. Influence of maternal gestational treatment with mycobacterial antigens on postnatal immunity in an experimental murine model.

    Directory of Open Access Journals (Sweden)

    Muhammad Jubayer Rahman

    Full Text Available BACKGROUND: It has been proposed that the immune system could be primed as early as during the fetal life and this might have an impact on postnatal vaccination. Therefore, we addressed in murine models whether gestational treatment with mycobacterial antigens could induce better immune responses in the postnatal life. METHODS/FINDINGS: BALB/c mice were treated subcutaneously (s.c. at the second week of gestation with antigen (Ag85A or heparin-binding hemagglutinin (HBHA in the absence of adjuvant. Following birth, offspring mice were immunized intranasally (i.n. with the same antigens formulated with the adjuvant cholera toxin (CT at week 1 and week 4. One week after the last immunization, we assessed antigen-specific recall interferon gamma (IFN-gamma responses by in vitro restimulation of lung-derived lymphocytes. Protection against infection was assessed by challenge with high dose Mycobacterium bovis Bacille Calmette-Guérin (BCG given i.n. We found that recall IFN-gamma responses were higher in the offspring born to the treated mother compared to the untreated-mother. More importantly, we observed that the offspring born to the treated mother controlled infection better than the offspring born to the untreated mother. Since the gestational treatment was done in absence of adjuvant, essentially there was no antibody production observed in the pregnant mice and therefore no influence of maternal antibodies was expected. We hypothesized that the effect of maternal treatment with antigen on the offspring occurred due to antigen transportation through placenta. To trace the antigens, we conjugated fluorescent nanocrystals with Ag85A (Qdot-ITK-Ag85A. After inoculation in the pregnant mice, Qdot-ITK-Ag85A conjugates were detected in the liver, spleen of pregnant females and in all the fetuses and placentas examined. CONCLUSION: The fetal immune system could be primed in utero by mycobacterial antigens transported through the placenta.

  14. 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.

  15. EFFECT OF IMMUNIZATION OF RABBIT WITH ZONA PELLUCIDA ANTIGEN ON CONCEPTION RATE AND LITTER SIZE

    Directory of Open Access Journals (Sweden)

    O. Fayemi

    2005-10-01

    Full Text Available Twenty mature female rabbits were divided into two equal groups. The first group was immunized with zona pellucida (ZP antigen and the second group was injected with phosphate buffered saline (PBS at the corresponding time of immunization (control group. When bred by male rabbits, the conception rate in the immunized group (30% was significantly lower (P<0.001 than 100% recorded for the unimmunized (control group. The litter size was 1.67 ± 0.50 for the immunized group and was significantly lower than 7.3 ± 0.82 for the control group (P< 0.001. It is concluded that ZP antigens may become better candidates for contraception than steroids.

  16. 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.

  17. Co-delivery of PLGA encapsulated invariant NKT cell agonist with antigenic protein induce strong T cell-mediated antitumor immune responses

    NARCIS (Netherlands)

    Dolen, Y.; Kreutz, M.; Gileadi, U.; Tel, J.; Vasaturo, A.; Dinther, E.A.W. van; Hout-Kuijer, M.A. van; Cerundolo, V.; Figdor, C.G.

    2016-01-01

    Antitumor immunity can be enhanced by the coordinated release and delivery of antigens and immune-stimulating agents to antigen-presenting cells via biodegradable vaccine carriers. So far, encapsulation of TLR ligands and tumor-associated antigens augmented cytotoxic T cell (CTLs) responses. Here,

  18. Chimeric antigen receptor T cells form nonclassical and potent immune synapses driving rapid cytotoxicity.

    Science.gov (United States)

    Davenport, A J; Cross, R S; Watson, K A; Liao, Y; Shi, W; Prince, H M; Beavis, P A; Trapani, J A; Kershaw, M H; Ritchie, D S; Darcy, P K; Neeson, P J; Jenkins, M R

    2018-02-27

    Chimeric antigen receptor T (CAR-T) cells are effective serial killers with a faster off-rate from dying tumor cells than CAR-T cells binding target cells through their T cell receptor (TCR). Here we explored the functional consequences of CAR-mediated signaling using a dual-specific CAR-T cell, where the same cell was triggered via TCR (tcrCTL) or CAR (carCTL). The carCTL immune synapse lacked distinct LFA-1 adhesion rings and was less reliant on LFA to form stable conjugates with target cells. carCTL receptors associated with the synapse were found to be disrupted and formed a convoluted multifocal pattern of Lck microclusters. Both proximal and distal receptor signaling pathways were induced more rapidly and subsequently decreased more rapidly in carCTL than in tcrCTL. The functional consequence of this rapid signaling in carCTL cells included faster lytic granule recruitment to the immune synapse, correlating with faster detachment of the CTL from the target cell. This study provides a mechanism for how CAR-T cells can debulk large tumor burden quickly and may contribute to further refinement of CAR design for enhancing the quality of signaling and programming of the T cell. Copyright © 2018 the Author(s). Published by PNAS.

  19. Prostate-specific membrane antigen-directed nanoparticle targeting for extreme nearfield ablation of prostate cancer cells.

    Science.gov (United States)

    Lee, Seung S; Roche, Philip Jr; Giannopoulos, Paresa N; Mitmaker, Elliot J; Tamilia, Michael; Paliouras, Miltiadis; Trifiro, Mark A

    2017-03-01

    Almost all biological therapeutic interventions cannot overcome neoplastic heterogeneity. Physical ablation therapy is immune to tumor heterogeneity, but nearby tissue damage is the limiting factor in delivering lethal doses. Multi-walled carbon nanotubes offer a number of unique properties: chemical stability, photonic properties including efficient light absorption, thermal conductivity, and extensive surface area availability for covalent chemical ligation. When combined together with a targeting moiety such as an antibody or small molecule, one can deliver highly localized temperature increases and cause extensive cellular damage. We have functionalized multi-walled carbon nanotubes by conjugating an antibody against prostate-specific membrane antigen. In our in vitro studies using prostate-specific membrane antigen-positive LNCaP prostate cancer cells, we have effectively demonstrated cell ablation of >80% with a single 30-s exposure to a 2.7-W, 532-nm laser for the first time without bulk heating. We also confirmed the specificity and selectivity of prostate-specific membrane antigen targeting by assessing prostate-specific membrane antigen-null PC3 cell lines under the same conditions (<10% cell ablation). This suggests that we can achieve an extreme nearfield cell ablation effect, thus restricting potential tissue damage when transferred to in vivo clinical applications. Developing this new platform will introduce novel approaches toward current therapeutic modalities and will usher in a new age of effective cancer treatment squarely addressing tumoral heterogeneity.

  20. Immune response to Lactobacillus plantarum expressing Borrelia burgdorferi OspA is modulated by the lipid modification of the antigen.

    Directory of Open Access Journals (Sweden)

    Beatriz del Rio

    2010-06-01

    Full Text Available Over the past decade there has been increasing interest in the use of lactic acid bacteria as mucosal delivery vehicles for vaccine antigens, microbicides and therapeutics. We investigated the mechanism by which a mucosal vaccine based in recombinant lactic acid bacteria breaks the immunological tolerance of the gut in order to elicit a protective immune response.We analyzed how the lipid modification of OspA affects the localization of the antigen in our delivery vehicle using a number of biochemistry techniques. Furthermore, we examined how OspA-expressing L. plantarum breaks the oral tolerance of the gut by stimulating human intestinal epithelial cells, peripheral blood mononuclear cells and monocyte derived dendritic cells and measuring cytokine production. We show that the leader peptide of OspA targets the protein to the cell envelope of L. plantarum, and it is responsible for protein export across the membrane. Mutation of the lipidation site in OspA redirects protein localization within the cell envelope. Further, we show that lipidated-OspA-expressing L. plantarum does not induce secretion of the pro-inflammatory cytokine IL-8 by intestinal epithelial cells. In addition, it breaks oral tolerance of the gut via Th1/Th2 cell mediated immunity, as shown by the production of pro- and anti-inflammatory cytokines by human dendritic cells, and by the production of IgG2a and IgG1 antibodies, respectively.Lipid modification of OspA expressed in L. plantarum modulates the immune response to this antigen through a Th1/Th2 immune response.

  1. Perillyl alcohol suppresses antigen-induced immune responses in the lung

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, Mitsuru; Sasaki, Oh; Okunishi, Katsuhide; Nakagome, Kazuyuki; Harada, Hiroaki; Kawahata, Kimito; Tanaka, Ryoichi; Yamamoto, Kazuhiko [Department of Allergy and Rheumatology, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan); Dohi, Makoto, E-mail: mdohi-tky@umin.ac.jp [Department of Allergy and Rheumatology, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan); Institute of Respiratory Immunology, Shibuya Clinic for Respiratory Diseases and Allergology, Tokyo (Japan)

    2014-01-03

    Highlights: •Perillyl alcohol (POH) is an isoprenoid which inhibits the mevalonate pathway. •We examined whether POH suppresses immune responses with a mouse model of asthma. •POH treatment during sensitization suppressed Ag-induced priming of CD4{sup +} T cells. •POH suppressed airway eosinophila and cytokine production in thoracic lymph nodes. -- Abstract: Perillyl alcohol (POH) is an isoprenoid which inhibits farnesyl transferase and geranylgeranyl transferase, key enzymes that induce conformational and functional changes in small G proteins to conduct signal production for cell proliferation. Thus, it has been tried for the treatment of cancers. However, although it affects the proliferation of immunocytes, its influence on immune responses has been examined in only a few studies. Notably, its effect on antigen-induced immune responses has not been studied. In this study, we examined whether POH suppresses Ag-induced immune responses with a mouse model of allergic airway inflammation. POH treatment of sensitized mice suppressed proliferation and cytokine production in Ag-stimulated spleen cells or CD4{sup +} T cells. Further, sensitized mice received aerosolized OVA to induce allergic airway inflammation, and some mice received POH treatment. POH significantly suppressed indicators of allergic airway inflammation such as airway eosinophilia. Cytokine production in thoracic lymph nodes was also significantly suppressed. These results demonstrate that POH suppresses antigen-induced immune responses in the lung. Considering that it exists naturally, POH could be a novel preventive or therapeutic option for immunologic lung disorders such as asthma with minimal side effects.

  2. Specific Nongluten Proteins of Wheat Are Novel Target Antigens in Celiac Disease Humoral Response

    Science.gov (United States)

    2014-01-01

    While the antigenic specificity and pathogenic relevance of immunologic reactivity to gluten in celiac disease have been extensively researched, the immune response to nongluten proteins of wheat has not been characterized. We aimed to investigate the level and molecular specificity of antibody response to wheat nongluten proteins in celiac disease. Serum samples from patients and controls were screened for IgG and IgA antibody reactivity to a nongluten protein extract from the wheat cultivar Triticum aestivum Butte 86. Antibodies were further analyzed for reactivity to specific nongluten proteins by two-dimensional gel electrophoresis and immunoblotting. Immunoreactive molecules were identified by tandem mass spectrometry. Compared with healthy controls, patients exhibited significantly higher levels of antibody reactivity to nongluten proteins. The main immunoreactive nongluten antibody target proteins were identified as serpins, purinins, α-amylase/protease inhibitors, globulins, and farinins. Assessment of reactivity toward purified recombinant proteins further confirmed the presence of antibody response to specific antigens. The results demonstrate that, in addition to the well-recognized immune reaction to gluten, celiac disease is associated with a robust humoral response directed at a specific subset of the nongluten proteins of wheat. PMID:25329597

  3. Generation of monoclonal antibodies against highly conserved antigens.

    Directory of Open Access Journals (Sweden)

    Hongzhe Zhou

    Full Text Available BACKGROUND: Therapeutic antibody development is one of the fastest growing areas of the pharmaceutical industry. Generating high-quality monoclonal antibodies against a given therapeutic target is very crucial for the success of the drug development. However, due to immune tolerance, some proteins that are highly conserved between mice and humans are not very immunogenic in mice, making it difficult to generate antibodies using a conventional approach. METHODOLOGY/PRINCIPAL FINDINGS: In this report, the impaired immune tolerance of NZB/W mice was exploited to generate monoclonal antibodies against highly conserved or self-antigens. Using two highly conserved human antigens (MIF and HMGB1 and one mouse self-antigen (TNF-alpha as examples, we demonstrate here that multiple clones of high affinity, highly specific antibodies with desired biological activities can be generated, using the NZB/W mouse as the immunization host and a T cell-specific tag fused to a recombinant antigen to stimulate the immune system. CONCLUSIONS/SIGNIFICANCE: We developed an efficient and universal method for generating surrogate or therapeutic antibodies against "difficult antigens" to facilitate the development of therapeutic antibodies.

  4. Immunoradiometric assay for quantification of serum antibodies to dental plaque antigen in immunized dogs

    International Nuclear Information System (INIS)

    Ahlstedt, S.; Rylander, H.

    1975-01-01

    An immunoradiometric assay (IRMA) was used for quantifying dog serum antibodies to antigens from dental plaque collected from full-grown dogs. The antigens were adsorbed onto the inner surface of plastic tubes and then incubated with dog-anti-plaque serum, 125 I-labelled anti-dog plasma-immunoglobulin was used for quantification of the specific antibodies. Four 10 months old Beagle dogs in excellent gingival health were immunized for 10 weeks with ultrasonicated dog dental plaque. The antibody levels in antisera sampled 6, 8, 10 and 11 weeks after the first antigen injection were 2 to 5 times as high as those recorded before the immunizing period. The variability of the assay as judged from the difference between duplicate samples was found to be 18 percent+-4 (p<0.01) of the mean value and the variability between the same serum ran on different test occasions 13 percent+-7 (p<0.01). The specificity of the antigen-antibody reaction in the immuno assay was tested by inhibition experiments. Preincubation of the antisera with dental plaque antigen significantly inhibited the antigen-antibody reaction in the IRMA, while bovine serum albumin did not. (author)

  5. Immunoradiometric assay for quantification of serum antibodies to dental plaque antigen in immunized dogs

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstedt, S; Rylander, H [Goeteborg Univ. (Sweden)

    1975-01-01

    An immunoradiometric assay (IRMA) was used for quantifying dog serum antibodies to antigens from dental plaque collected from full-grown dogs. The antigens were adsorbed onto the inner surface of plastic tubes and then incubated with dog-anti-plaque serum, /sup 125/I-labelled anti-dog plasma-immunoglobulin was used for quantification of the specific antibodies. Four 10 months old Beagle dogs in excellent gingival health were immunized for 10 weeks with ultrasonicated dog dental plaque. The antibody levels in antisera sampled 6, 8, 10 and 11 weeks after the first antigen injection were 2 to 5 times as high as those recorded before the immunizing period. The variability of the assay as judged from the difference between duplicate samples was found to be 18 percent+-4 (p<0.01) of the mean value and the variability between the same serum ran on different test occasions 13 percent+-7 (p<0.01). The specificity of the antigen-antibody reaction in the immuno assay was tested by inhibition experiments. Preincubation of the antisera with dental plaque antigen significantly inhibited the antigen-antibody reaction in the IRMA, while bovine serum albumin did not.

  6. Reduction-sensitive dextran nanogels aimed for intracellular delivery of antigens

    NARCIS (Netherlands)

    Li, Dandan; Kordalivand, Neda; Fransen, Marieke F.; Ossendorp, Ferry; Raemdonck, Koen; Vermonden, Tina; Hennink, Wim E.; Van Nostrum, Cornelus F.

    2015-01-01

    Targeting of antigens to dendritic cells (DCs) to induce strong cellular immune response can be established by loading in a nano-sized carrier and keeping the antigen associated with the particles until they are internalized by DCs. In the present study, a model antigen (ovalbumin, OVA) is

  7. Lipopolysaccharide O-antigen delays plant innate immune recognition of Xylella fastidiosa.

    Science.gov (United States)

    Rapicavoli, Jeannette N; Blanco-Ulate, Barbara; Muszyński, Artur; Figueroa-Balderas, Rosa; Morales-Cruz, Abraham; Azadi, Parastoo; Dobruchowska, Justyna M; Castro, Claudia; Cantu, Dario; Roper, M Caroline

    2018-01-26

    Lipopolysaccharides (LPS) are among the known pathogen-associated molecular patterns (PAMPs). LPSs are potent elicitors of PAMP-triggered immunity (PTI), and bacteria have evolved intricate mechanisms to dampen PTI. Here we demonstrate that Xylella fastidiosa (Xf), a hemibiotrophic plant pathogenic bacterium, possesses a long chain O-antigen that enables it to delay initial plant recognition, thereby allowing it to effectively skirt initial elicitation of innate immunity and establish itself in the host. Lack of the O-antigen modifies plant perception of Xf and enables elicitation of hallmarks of PTI, such as ROS production specifically in the plant xylem tissue compartment, a tissue not traditionally considered a spatial location of PTI. To explore translational applications of our findings, we demonstrate that pre-treatment of plants with Xf LPS primes grapevine defenses to confer tolerance to Xf challenge.

  8. Host Immunization with Recombinant Proteins to Screen Antigens for Tick Control.

    Science.gov (United States)

    Galay, Remil Linggatong; Miyata, Takeshi; Umemiya-Shirafuji, Rika; Mochizuki, Masami; Fujisaki, Kozo; Tanaka, Tetsuya

    2016-01-01

    Ticks (Parasitiformes: Ixodida) are known for their obligate blood feeding habit and their role in transmitting pathogens to various vertebrate hosts. Tick control using chemical acaricides is extensively used particularly in livestock management, but several disadvantages arise from resistance development of many tick species, and concerns on animal product and environmental contamination. Vaccination offers better protection and more cost-effective alternative to application of chemical acaricides, addressing their disadvantages. However, an ideal anti-tick vaccine targeting multiple tick species and all the tick stages is still wanting. Here, we describe the procedures involved in the evaluation of a vaccine candidate antigen against ticks at the laboratory level, from the preparation of recombinant proteins, administration to the rabbit host and monitoring of antibody titer, to tick infestation challenge and determination of the effects of immunization to ticks.

  9. 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

  10. Maximum-Entropy Models of Sequenced Immune Repertoires Predict Antigen-Antibody Affinity.

    Directory of Open Access Journals (Sweden)

    Lorenzo Asti

    2016-04-01

    Full Text Available The immune system has developed a number of distinct complex mechanisms to shape and control the antibody repertoire. One of these mechanisms, the affinity maturation process, works in an evolutionary-like fashion: after binding to a foreign molecule, the antibody-producing B-cells exhibit a high-frequency mutation rate in the genome region that codes for the antibody active site. Eventually, cells that produce antibodies with higher affinity for their cognate antigen are selected and clonally expanded. Here, we propose a new statistical approach based on maximum entropy modeling in which a scoring function related to the binding affinity of antibodies against a specific antigen is inferred from a sample of sequences of the immune repertoire of an individual. We use our inference strategy to infer a statistical model on a data set obtained by sequencing a fairly large portion of the immune repertoire of an HIV-1 infected patient. The Pearson correlation coefficient between our scoring function and the IC50 neutralization titer measured on 30 different antibodies of known sequence is as high as 0.77 (p-value 10-6, outperforming other sequence- and structure-based models.

  11. Modulation of Immune Responses by Exosomes Derived from Antigen-Presenting Cells

    Directory of Open Access Journals (Sweden)

    Botros B. Shenoda

    2016-01-01

    Full Text Available Exosome-mediated signaling is important in mediating the inflammatory response. To exert their biological or pathophysiological functions in the recipient cells, exosomes deliver a diverse array of biomacromolecules including long and short coding and non-coding RNAs, proteins, and lipids. Exosomes secreted by antigen-presenting cells can confer therapeutic benefits by attenuating or stimulating the immune response. Exosomes play a crucial role in carrying and presenting functional major histocompatibility peptide complexes to modulate antigen-specific T cell responses. Exosomes from Dendritic Cells (DCs can activate T and B cells and have been explored for their immunostimulatory properties in cancer therapy. The immunosuppressive properties of exosomes derived from macrophages and DCs can reduce inflammation in animal models for several inflammatory disorders. This review focuses on the protective role of exosomes in attenuating inflammation or augmenting immune response, emphasizing studies on exosomes derived from DCs and macrophages.

  12. M cell-targeting strategy facilitates mucosal immune response and enhances protection against CVB3-induced viral myocarditis elicited by chitosan-DNA vaccine.

    Science.gov (United States)

    Ye, Ting; Yue, Yan; Fan, Xiangmei; Dong, Chunsheng; Xu, Wei; Xiong, Sidong

    2014-07-31

    Efficient delivery of antigen to mucosal associated lymphoid tissue is a first and critical step for successful induction of mucosal immunity by vaccines. Considering its potential transcytotic capability, M cell has become a more and more attractive target for mucosal vaccines. In this research, we designed an M cell-targeting strategy by which mucosal delivery system chitosan (CS) was endowed with M cell-targeting ability via conjugating with a CPE30 peptide, C terminal 30 amino acids of clostridium perfringens enterotoxin (CPE), and then evaluated its immune-enhancing ability in the context of coxsackievirus B3 (CVB3)-specific mucosal vaccine consisting of CS and a plasmid encoding CVB3 predominant antigen VP1. It had shown that similar to CS-pVP1, M cell-targeting CPE30-CS-pVP1 vaccine appeared a uniform spherical shape with about 300 nm diameter and +22 mV zeta potential, and could efficiently protect DNA from DNase I digestion. Mice were orally immunized with 4 doses of CPE30-CS-pVP1 containing 50 μg pVP1 at 2-week intervals and challenged with CVB3 4 weeks after the last immunization. Compared with CS-pVP1 vaccine, CPE30-CS-pVP1 vaccine had no obvious impact on CVB3-specific serum IgG level and splenic T cell immune responses, but significantly increased specific fecal SIgA level and augmented mucosal T cell immune responses. Consequently, much milder myocarditis and lower viral load were witnessed in CPE30-CS-pVP1 immunized group. The enhanced immunogenicity and immunoprotection were associated with the M cell-targeting ability of CPE30-CS-pVP1 which improved its mucosal uptake and transcytosis. Our findings indicated that CPE30-CS-pVP1 may represent a novel prophylactic vaccine against CVB3-induced myocarditis, and this M cell-targeting strategy indeed could be applied as a promising and universal platform for mucosal vaccine development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Profiling Humoral Immune Responses to Clostridium difficile-Specific Antigens by Protein Microarray Analysis.

    Science.gov (United States)

    Negm, Ola H; Hamed, Mohamed R; Dilnot, Elizabeth M; Shone, Clifford C; Marszalowska, Izabela; Lynch, Mark; Loscher, Christine E; Edwards, Laura J; Tighe, Patrick J; Wilcox, Mark H; Monaghan, Tanya M

    2015-09-01

    Clostridium difficile is an anaerobic, Gram-positive, and spore-forming bacterium that is the leading worldwide infective cause of hospital-acquired and antibiotic-associated diarrhea. Several studies have reported associations between humoral immunity and the clinical course of C. difficile infection (CDI). Host humoral immune responses are determined using conventional enzyme-linked immunosorbent assay (ELISA) techniques. Herein, we report the first use of a novel protein microarray assay to determine systemic IgG antibody responses against a panel of highly purified C. difficile-specific antigens, including native toxins A and B (TcdA and TcdB, respectively), recombinant fragments of toxins A and B (TxA4 and TxB4, respectively), ribotype-specific surface layer proteins (SLPs; 001, 002, 027), and control proteins (tetanus toxoid and Candida albicans). Microarrays were probed with sera from a total of 327 individuals with CDI, cystic fibrosis without diarrhea, and healthy controls. For all antigens, precision profiles demonstrated ELISA in the quantification of antitoxin A and antitoxin B IgG. These results indicate that microarray is a suitable assay for defining humoral immune responses to C. difficile protein antigens and may have potential advantages in throughput, convenience, and cost. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. OptMAVEn--a new framework for the de novo design of antibody variable region models targeting specific antigen epitopes.

    Directory of Open Access Journals (Sweden)

    Tong Li

    Full Text Available Antibody-based therapeutics provides novel and efficacious treatments for a number of diseases. Traditional experimental approaches for designing therapeutic antibodies rely on raising antibodies against a target antigen in an immunized animal or directed evolution of antibodies with low affinity for the desired antigen. However, these methods remain time consuming, cannot target a specific epitope and do not lead to broad design principles informing other studies. Computational design methods can overcome some of these limitations by using biophysics models to rationally select antibody parts that maximize affinity for a target antigen epitope. This has been addressed to some extend by OptCDR for the design of complementary determining regions. Here, we extend this earlier contribution by addressing the de novo design of a model of the entire antibody variable region against a given antigen epitope while safeguarding for immunogenicity (Optimal Method for Antibody Variable region Engineering, OptMAVEn. OptMAVEn simulates in silico the in vivo steps of antibody generation and evolution, and is capable of capturing the critical structural features responsible for affinity maturation of antibodies. In addition, a humanization procedure was developed and incorporated into OptMAVEn to minimize the potential immunogenicity of the designed antibody models. As case studies, OptMAVEn was applied to design models of neutralizing antibodies targeting influenza hemagglutinin and HIV gp120. For both HA and gp120, novel computational antibody models with numerous interactions with their target epitopes were generated. The observed rates of mutations and types of amino acid changes during in silico affinity maturation are consistent with what has been observed during in vivo affinity maturation. The results demonstrate that OptMAVEn can efficiently generate diverse computational antibody models with both optimized binding affinity to antigens and reduced

  15. A compound chimeric antigen receptor strategy for targeting multiple myeloma.

    Science.gov (United States)

    Chen, K H; Wada, M; Pinz, K G; Liu, H; Shuai, X; Chen, X; Yan, L E; Petrov, J C; Salman, H; Senzel, L; Leung, E L H; Jiang, X; Ma, Y

    2018-02-01

    Current clinical outcomes using chimeric-antigen receptors (CARs) against multiple myeloma show promise in the eradication of bulk disease. However, these anti-BCMA (CD269) CARs observe relapse as a common phenomenon after treatment due to the reemergence of either antigen-positive or -negative cells. Hence, the development of improvements in CAR design to target antigen loss and increase effector cell persistency represents a critical need. Here, we report on the anti-tumor activity of a CAR T-cell possessing two complete and independent CAR receptors against the multiple myeloma antigens BCMA and CS1. We determined that the resulting compound CAR (cCAR) T-cell possesses consistent, potent and directed cytotoxicity against each target antigen population. Using multiple mouse models of myeloma and mixed cell populations, we are further able to show superior in vivo survival by directed cytotoxicity against multiple populations compared to a single-expressing CAR T-cell. These findings indicate that compound targeting of BCMA and CS1 on myeloma cells can potentially be an effective strategy for augmenting the response against myeloma bulk disease and for initiation of broader coverage CAR therapy.

  16. Profiling the Targets of Protective CD8+ T Cell Responses to Infection

    Directory of Open Access Journals (Sweden)

    Joseph T. Bruder

    2017-12-01

    Full Text Available T cells are critical effectors of host immunity that target intracellular pathogens, such as the causative agents of HIV, tuberculosis, and malaria. The development of vaccines that induce effective cell-mediated immunity against such pathogens has proved challenging; for tuberculosis and malaria, many of the antigens targeted by protective T cells are not known. Here, we report a novel approach for screening large numbers of antigens as potential targets of T cells. Malaria provides an excellent model to test this antigen discovery platform because T cells are critical mediators of protection following immunization with live sporozoite vaccines and the specific antigen targets are unknown. We generated an adenovirus array by cloning 312 highly expressed pre-erythrocytic Plasmodium yoelii antigens into adenovirus vectors using high-throughput methodologies. The array was screened to identify antigen-specific CD8+ T cells induced by a live sporozoite vaccine regimen known to provide high levels of sterile protection mediated by CD8+ T cells. We identified 69 antigens that were targeted by CD8+ T cells induced by this vaccine regimen. The antigen that recalled the highest frequency of CD8+ T cells, PY02605, induced protective responses in mice, demonstrating proof of principle for this approach in identifying antigens for vaccine development.

  17. Evaluation of the immune response to CRA and FRA recombinant antigens of Trypanosoma cruzi in C57BL/6 mice.

    Science.gov (United States)

    Pereira, Valéria Rêgo Alves; de Lorena, Virginia Maria Barros; Nakazawa, Mineo; da Silva, Ana Paula Galvão; Montarroyos, Ulisses; Correa-Oliveira, Rodrigo; Gomes, Yara de Miranda

    2003-01-01

    Humoral and cellular immune responses were evaluated in 44 C57BL/6 mice immunized with the Trypanosoma cruzi recombinant antigens CRA and FRA. Both antigens induced cutaneous immediate-type hypersensitivity response. The levels of IgG1, IgG2a, IgG2b and IgG3 were high in CRA immunized mice. IgG3 was the predominant isotype. Although no difference in antibody levels was observed in FRA-immunized mice when compared to control mice, both antigens were able to induce lymphoproliferation in immunized mice. Significant differences were observed between incorporation of [ H]- thymidine by spleen cell stimulated in vitro with CRA or FRA and the control group. These results suggest that CRA and FRA could be involved in mechanisms of resistance to Trypanosoma cruzi infection.

  18. Porcine sialoadhesin (CD169/Siglec-1 is an endocytic receptor that allows targeted delivery of toxins and antigens to macrophages.

    Directory of Open Access Journals (Sweden)

    Peter L Delputte

    Full Text Available Sialoadhesin is exclusively expressed on specific subpopulations of macrophages. Since sialoadhesin-positive macrophages are involved in inflammatory autoimmune diseases, such as multiple sclerosis, and potentially in the generation of immune responses, targeted delivery of drugs, toxins or antigens via sialoadhesin-specific immunoconjugates may prove a useful therapeutic strategy. Originally, sialoadhesin was characterized as a lymphocyte adhesion molecule, though recently its involvement in internalization of sialic acid carrying pathogens was shown, suggesting that sialoadhesin is an endocytic receptor. In this report, we show that porcine sialoadhesin-specific antibodies and F(ab'₂ fragments trigger sialoadhesin internalization, both in primary porcine macrophages and in cells expressing recombinant porcine sialoadhesin. Using chemical inhibitors, double immunofluorescence stainings and dominant-negative constructs, porcine sialoadhesin internalization was shown to be clathrin- and Eps15-dependent and to result in targeting to early endosomes but not lysosomes. Besides characterizing the sialoadhesin endocytosis mechanism, two sialoadhesin-specific immunoconjugates were evaluated. We observed that porcine sialoadhesin-specific immunotoxins efficiently kill sialoadhesin-expressing macrophages. Furthermore, porcine sialoadhesin-specific albumin immunoconjugates were shown to be internalized in macrophages and immunization with these immunoconjugates resulted in a rapid and robust induction of albumin-specific antibodies, this compared to immunization with albumin alone. Together, these data expand sialoadhesin functionality and show that it can function as an endocytic receptor, a feature that cannot only be misused by sialic acid carrying pathogens, but that may also be used for specific targeting of toxins or antigens to sialoadhesin-expressing macrophages.

  19. EGFRvIII mCAR-modified T-cell therapy cures mice with established intracerebral glioma and generates host immunity against tumor-antigen loss.

    Science.gov (United States)

    Sampson, John H; Choi, Bryan D; Sanchez-Perez, Luis; Suryadevara, Carter M; Snyder, David J; Flores, Catherine T; Schmittling, Robert J; Nair, Smita K; Reap, Elizabeth A; Norberg, Pamela K; Herndon, James E; Kuan, Chien-Tsun; Morgan, Richard A; Rosenberg, Steven A; Johnson, Laura A

    2014-02-15

    Chimeric antigen receptor (CAR) transduced T cells represent a promising immune therapy that has been shown to successfully treat cancers in mice and humans. However, CARs targeting antigens expressed in both tumors and normal tissues have led to significant toxicity. Preclinical studies have been limited by the use of xenograft models that do not adequately recapitulate the immune system of a clinically relevant host. A constitutively activated mutant of the naturally occurring epidermal growth factor receptor (EGFRvIII) is antigenically identical in both human and mouse glioma, but is also completely absent from any normal tissues. We developed a third-generation, EGFRvIII-specific murine CAR (mCAR), and performed tests to determine its efficacy in a fully immunocompetent mouse model of malignant glioma. At elevated doses, infusion with EGFRvIII mCAR T cells led to cures in all mice with brain tumors. In addition, antitumor efficacy was found to be dependent on lymphodepletive host conditioning. Selective blockade with EGFRvIII soluble peptide significantly abrogated the activity of EGFRvIII mCAR T cells in vitro and in vivo, and may offer a novel strategy to enhance the safety profile for CAR-based therapy. Finally, mCAR-treated, cured mice were resistant to rechallenge with EGFRvIII(NEG) tumors, suggesting generation of host immunity against additional tumor antigens. All together, these data support that third-generation, EGFRvIII-specific mCARs are effective against gliomas in the brain and highlight the importance of syngeneic, immunocompetent models in the preclinical evaluation of tumor immunotherapies. ©2013 AACR

  20. 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

  1. Chimeric Antigen Receptor-Engineered NK-92 Cells: An Off-the-Shelf Cellular Therapeutic for Targeted Elimination of Cancer Cells and Induction of Protective Antitumor Immunity

    Directory of Open Access Journals (Sweden)

    Congcong Zhang

    2017-05-01

    Full Text Available Significant progress has been made in recent years toward realizing the potential of natural killer (NK cells for cancer immunotherapy. NK cells can respond rapidly to transformed and stressed cells and have the intrinsic potential to extravasate and reach their targets in almost all body tissues. In addition to donor-derived primary NK cells, also the established NK cell line NK-92 is being developed for adoptive immunotherapy, and general safety of infusion of irradiated NK-92 cells has been established in phase I clinical trials with clinical responses observed in some of the cancer patients treated. To enhance their therapeutic utility, NK-92 cells have been modified to express chimeric antigen receptors (CARs composed of a tumor-specific single chain fragment variable antibody fragment fused via hinge and transmembrane regions to intracellular signaling moieties such as CD3ζ or composite signaling domains containing a costimulatory protein together with CD3ζ. CAR-mediated activation of NK cells then bypasses inhibitory signals and overcomes NK resistance of tumor cells. In contrast to primary NK cells, CAR-engineered NK-92 cell lines suitable for clinical development can be established from molecularly and functionally well-characterized single cell clones following good manufacturing practice-compliant procedures. In preclinical in vitro and in vivo models, potent antitumor activity of NK-92 variants targeted to differentiation antigens expressed by hematologic malignancies, and overexpressed or mutated self-antigens associated with solid tumors has been found, encouraging further development of CAR-engineered NK-92 cells. Importantly, in syngeneic mouse tumor models, induction of endogenous antitumor immunity after treatment with CAR-expressing NK-92 cells has been demonstrated, resulting in cures and long-lasting immunological memory protecting against tumor rechallenge at distant sites. Here, we summarize the current status and future

  2. The immune system strikes back: cellular immune responses against indoleamine 2,3-dioxygenase

    DEFF Research Database (Denmark)

    Sørensen, Rikke Baek; Berge-Hansen, Linda; Junker, Niels

    2009-01-01

    BACKGROUND: The enzyme indoleamine 2,3-dioxygenase (IDO) exerts an well established immunosuppressive function in cancer. IDO is expressed within the tumor itself as well as in antigen-presenting cells in tumor-draining lymph nodes, where it promotes the establishment of peripheral immune tolerance...... to tumor antigens. In the present study, we tested the notion whether IDO itself may be subject to immune responses. METHODS AND FINDINGS: The presence of naturally occurring IDO-specific CD8 T cells in cancer patients was determined by MHC/peptide stainings as well as ELISPOT. Antigen specific cytotoxic T...... of the major immune suppressive cell populations. CONCLUSION: IDO may serve as an important and widely applicable target for anti-cancer immunotherapeutic strategies. Furthermore, as emerging evidence suggests that IDO constitutes a significant counter-regulatory mechanism induced by pro-inflammatory signals...

  3. Structure-guided evolution of antigenically distinct adeno-associated virus variants for immune evasion.

    Science.gov (United States)

    Tse, Longping Victor; Klinc, Kelli A; Madigan, Victoria J; Castellanos Rivera, Ruth M; Wells, Lindsey F; Havlik, L Patrick; Smith, J Kennon; Agbandje-McKenna, Mavis; Asokan, Aravind

    2017-06-13

    Preexisting neutralizing antibodies (NAbs) against adeno-associated viruses (AAVs) pose a major, unresolved challenge that restricts patient enrollment in gene therapy clinical trials using recombinant AAV vectors. Structural studies suggest that despite a high degree of sequence variability, antibody recognition sites or antigenic hotspots on AAVs and other related parvoviruses might be evolutionarily conserved. To test this hypothesis, we developed a structure-guided evolution approach that does not require selective pressure exerted by NAbs. This strategy yielded highly divergent antigenic footprints that do not exist in natural AAV isolates. Specifically, synthetic variants obtained by evolving murine antigenic epitopes on an AAV serotype 1 capsid template can evade NAbs without compromising titer, transduction efficiency, or tissue tropism. One lead AAV variant generated by combining multiple evolved antigenic sites effectively evades polyclonal anti-AAV1 neutralizing sera from immunized mice and rhesus macaques. Furthermore, this variant displays robust immune evasion in nonhuman primate and human serum samples at dilution factors as high as 1:5, currently mandated by several clinical trials. Our results provide evidence that antibody recognition of AAV capsids is conserved across species. This approach can be applied to any AAV strain to evade NAbs in prospective patients for human gene therapy.

  4. Multiplexed screening of natural humoral immunity identifies antibodies at fine specificity for complex and dynamic viral targets.

    Science.gov (United States)

    McCutcheon, Krista M; Gray, Julia; Chen, Natalie Y; Liu, Keyi; Park, Minha; Ellsworth, Stote; Tripp, Ralph A; Tompkins, S Mark; Johnson, Scott K; Samet, Shelly; Pereira, Lenore; Kauvar, Lawrence M

    2014-01-01

    Viral entry targets with therapeutic neutralizing potential are subject to multiple escape mechanisms, including antigenic drift, immune dominance of functionally irrelevant epitopes, and subtle variations in host cell mechanisms. A surprising finding of recent years is that potent neutralizing antibodies to viral epitopes independent of strain exist, but are poorly represented across the diverse human population. Identifying these antibodies and understanding the biology mediating the specific immune response is thus difficult. An effective strategy for meeting this challenge is to incorporate multiplexed antigen screening into a high throughput survey of the memory B cell repertoire from immune individuals. We used this approach to discover suites of cross-clade antibodies directed to conformational epitopes in the stalk region of the influenza A hemagglutinin (HA) protein and to select high-affinity anti-peptide antibodies to the glycoprotein B (gB) of human cytomegalovirus. In each case, our screens revealed a restricted VH and VL germline usage, including published and previously unidentified gene families. The in vivo evolution of paratope specificity with optimal neutralizing activity was understandable after correlating biological activities with kinetic binding and epitope recognition. Iterative feedback between antigen probe design based on structure and function information with high throughput multiplexed screening demonstrated a generally applicable strategy for efficient identification of safe, native, finely tuned antibodies with the potential for high genetic barriers to viral escape.

  5. Immune responses of B. malayi thioredoxin (TRX) and venom allergen homologue (VAH) chimeric multiple antigen for lymphatic filariasis.

    Science.gov (United States)

    Anugraha, Gandhirajan; Jeyaprita, Parasurama Jawaharlal; Madhumathi, Jayaprakasam; Sheeba, Tamilvanan; Kaliraj, Perumal

    2013-12-01

    Although multiple vaccine strategy for lymphatic filariasis has provided tremendous hope, the choice of antigens used in combination has determined its success in the previous studies. Multiple antigens comprising key vaccine candidates from different life cycle stages would provide a promising strategy if the antigenic combination is chosen by careful screening. In order to analyze one such combination, we have used a chimeric construct carrying the well studied B. malayi antigens thioredoxin (BmTRX) and venom allergen homologue (BmVAH) as a fusion protein (TV) and evaluated its immune responses in mice model. The efficacy of fusion protein vaccine was explored in comparison with the single antigen vaccines and their cocktail. In mice, TV induced significantly high antibody titer of 1,28,000 compared to cocktail vaccine TRX+VAH (50,000) and single antigen vaccine TRX (16,000) or VAH (50,000). Furthermore, TV elicited higher level of cellular proliferative response together with elevated levels of IFN-γ, IL-4 and IL-5 indicating a Th1/Th2 balanced response. The isotype antibody profile showed significantly high level of IgG1 and IgG2b confirming the balanced response elicited by TV. Immunization with TV antigen induced high levels of both humoral and cellular immune responses compared to either cocktail or antigen given alone. The result suggests that TV is highly immunogenic in mice and hence the combination needs to be evaluated for its prophylactic potential.

  6. Primary pulmonary immunity to a soluble antigen in the dog

    International Nuclear Information System (INIS)

    Weissman, D.N.; Bice, D.E.; Muggenburg, B.A.; Schuyler, M.R.

    1988-01-01

    In order to study primary lung immunity to soluble antigen, Beagle dogs underwent trans-bronchoscopic instillation of 10 mg keyhole limpet hemocyanin (KLH) into the right cardiac lobe and saline into the left cardiac lobe. Over the next 3 wk, specific immune responses were monitored in blood and bronchoalveolar lavage (BAL) fluids obtained from immunized and control lung lobes. Primary lung immunization of dogs with KLH resulted in easily measurable specific IgG, IgM, and IgA responses in blood and bronchoalveolar lavage fluids. Important class differences were noted to exist for these responses. Levels of specific IgG and IgA in BAL remained elevated at 21 days after immunization, while BAL-specific IgM levels fell to control values by 12 days after immunization. In unimmunized lung lobes, specific antibody levels in BAL and production of specific antibody by bronchoalveolar lavage cells was far greater for IgG than for IgM or IgA. Finally, despite easily detectable specific IgA in serum and BAL fluid, production of specific IgA by peripheral blood mononuclear cells or bronchoalveolar lavage cells after primary lung immunization with KLH could not be demonstrated, suggesting that specific IgA was produced by a compartment of cells poorly sampled in blood and BAL. (author)

  7. Primary pulmonary immunity to a soluble antigen in the dog

    Energy Technology Data Exchange (ETDEWEB)

    Weissman, D N; Bice, D E; Muggenburg, B A; Schuyler, M R

    1988-12-01

    In order to study primary lung immunity to soluble antigen, Beagle dogs underwent trans-bronchoscopic instillation of 10 mg keyhole limpet hemocyanin (KLH) into the right cardiac lobe and saline into the left cardiac lobe. Over the next 3 wk, specific immune responses were monitored in blood and bronchoalveolar lavage (BAL) fluids obtained from immunized and control lung lobes. Primary lung immunization of dogs with KLH resulted in easily measurable specific IgG, IgM, and IgA responses in blood and bronchoalveolar lavage fluids. Important class differences were noted to exist for these responses. Levels of specific IgG and IgA in BAL remained elevated at 21 days after immunization, while BAL-specific IgM levels fell to control values by 12 days after immunization. In unimmunized lung lobes, specific antibody levels in BAL and production of specific antibody by bronchoalveolar lavage cells was far greater for IgG than for IgM or IgA. Finally, despite easily detectable specific IgA in serum and BAL fluid, production of specific IgA by peripheral blood mononuclear cells or bronchoalveolar lavage cells after primary lung immunization with KLH could not be demonstrated, suggesting that specific IgA was produced by a compartment of cells poorly sampled in blood and BAL. (author)

  8. Identifying Patient-Specific Epstein-Barr Nuclear Antigen-1 Genetic Variation and Potential Autoreactive Targets Relevant to Multiple Sclerosis Pathogenesis.

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    Monika Tschochner

    Full Text Available Epstein-Barr virus (EBV infection represents a major environmental risk factor for multiple sclerosis (MS, with evidence of selective expansion of Epstein-Barr Nuclear Antigen-1 (EBNA1-specific CD4+ T cells that cross-recognize MS-associated myelin antigens in MS patients. HLA-DRB1*15-restricted antigen presentation also appears to determine susceptibility given its role as a dominant risk allele. In this study, we have utilised standard and next-generation sequencing techniques to investigate EBNA-1 sequence variation and its relationship to HLA-DR15 binding affinity, as well as examining potential cross-reactive immune targets within the central nervous system proteome.Sanger sequencing was performed on DNA isolated from peripheral blood samples from 73 Western Australian MS cases, without requirement for primary culture, with additional FLX 454 Roche sequencing in 23 samples to identify low-frequency variants. Patient-derived viral sequences were used to predict HLA-DRB1*1501 epitopes (NetMHCII, NetMHCIIpan and candidates were evaluated for cross recognition with human brain proteins.EBNA-1 sequence variation was limited, with no evidence of multiple viral strains and only low levels of variation identified by FLX technology (8.3% nucleotide positions at a 1% cut-off. In silico epitope mapping revealed two known HLA-DRB1*1501-restricted epitopes ('AEG': aa 481-496 and 'MVF': aa 562-577, and two putative epitopes between positions 502-543. We identified potential cross-reactive targets involving a number of major myelin antigens including experimentally confirmed HLA-DRB1*15-restricted epitopes as well as novel candidate antigens within myelin and paranodal assembly proteins that may be relevant to MS pathogenesis.This study demonstrates the feasibility of obtaining autologous EBNA-1 sequences directly from buffy coat samples, and confirms divergence of these sequences from standard laboratory strains. This approach has identified a number of

  9. Human immune cell targeting of protein nanoparticles - caveospheres

    Science.gov (United States)

    Glass, Joshua J.; Yuen, Daniel; Rae, James; Johnston, Angus P. R.; Parton, Robert G.; Kent, Stephen J.; de Rose, Robert

    2016-04-01

    Nanotechnology has the power to transform vaccine and drug delivery through protection of payloads from both metabolism and off-target effects, while facilitating specific delivery of cargo to immune cells. However, evaluation of immune cell nanoparticle targeting is conventionally restricted to monocultured cell line models. We generated human caveolin-1 nanoparticles, termed caveospheres, which were efficiently functionalized with monoclonal antibodies. Using this platform, we investigated CD4+ T cell and CD20+ B cell targeting within physiological mixtures of primary human blood immune cells using flow cytometry, imaging flow cytometry and confocal microscopy. Antibody-functionalization enhanced caveosphere binding to targeted immune cells (6.6 to 43.9-fold) within mixed populations and in the presence of protein-containing fluids. Moreover, targeting caveospheres to CCR5 enabled caveosphere internalization by non-phagocytic CD4+ T cells--an important therapeutic target for HIV treatment. This efficient and flexible system of immune cell-targeted caveosphere nanoparticles holds promise for the development of advanced immunotherapeutics and vaccines.

  10. Interplay between immune responses to HLA and non-HLA self-antigens in allograft rejection.

    Science.gov (United States)

    Angaswamy, Nataraju; Tiriveedhi, Venkataswarup; Sarma, Nayan J; Subramanian, Vijay; Klein, Christina; Wellen, Jason; Shenoy, Surendra; Chapman, William C; Mohanakumar, T

    2013-11-01

    Recent studies strongly suggest an increasing role for immune responses against self-antigens (Ags) which are not encoded by the major histocompatibility complex in the immunopathogenesis of allograft rejection. Although, improved surgical techniques coupled with improved methods to detect and avoid sensitization against donor human leukocyte antigen (HLA) have improved the immediate and short term function of transplanted organs. However, acute and chronic rejection still remains a vexing problem for the long term function of the transplanted organ. Immediately following organ transplantation, several factors both immune and non immune mechanisms lead to the development of local inflammatory milieu which sets the stage for allograft rejection. Traditionally, development of antibodies (Abs) against mismatched donor HLA have been implicated in the development of Ab mediated rejection. However, recent studies from our laboratory and others have demonstrated that development of humoral and cellular immune responses against non-HLA self-Ags may contribute in the pathogenesis of allograft rejection. There are reports demonstrating that immune responses to self-Ags especially Abs to the self-Ags as well as cellular immune responses especially through IL17 has significant pro-fibrotic properties leading to chronic allograft failure. This review summarizes recent studies demonstrating the role for immune responses to self-Ags in allograft immunity leading to rejection as well as present recent evidence suggesting there is interplay between allo- and autoimmunity leading to allograft dysfunction. Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  11. Humoral and cellular immune responses in BALB/c and C57BL/6 mice immunized with cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive antigens, in acute experimental Trypanosoma cruzi infection.

    Science.gov (United States)

    Pereira, Valéria R A; Lorena, Virginia M B; Nakazawa, Mineo; Luna, Carlos F; Silva, Edimilson D; Ferreira, Antonio G P; Krieger, Marco Aurélio; Goldenberg, Samuel; Soares, Milena B P; Coutinho, Eridan M; Correa-Oliveira, Rodrigo; Gomes, Yara M

    2005-06-01

    In previous studies, cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) proteins induced specific humoral and cellular immune responses in susceptible and resistant mice in the absence of Trypanosoma cruzi infection with a significant induction of the Interferon-gamma (IFN-gamma) production in those animals. In this follow-up paper, the immunostimulatory and protective effects of these proteins were evaluated by immunizing with CRA or FRA antigens, BALB/c and C57BL/6 mice and challenging with a T. cruzi (Y strain). Both proteins induced humoral response with high levels of IgG isotypes as well as cellular immunity with high levels of IFN-gamma when compared to controls. However, the lymphocyte proliferative response was minimal. The survival rate at 30 days post-infection was significant in CRA (60%) or FRA (50%)--immunized BALB/c mice and CRA (83.3%)--immunized C57BL/6 mice. Taken as a whole these findings indicate that CRA and FRA are immunogenic and potentially important for protective immunity.

  12. Genetic engineering of chimeric antigen receptors using lamprey derived variable lymphocyte receptors

    Directory of Open Access Journals (Sweden)

    Robert Moot

    2016-01-01

    Full Text Available Chimeric antigen receptors (CARs are used to redirect effector cell specificity to selected cell surface antigens. Using CARs, antitumor activity can be initiated in patients with no prior tumor specific immunity. Although CARs have shown promising clinical results, the technology remains limited by the availability of specific cognate cell target antigens. To increase the repertoire of targetable tumor cell antigens we utilized the immune system of the sea lamprey to generate directed variable lymphocyte receptors (VLRs. VLRs serve as membrane bound and soluble immune effectors analogous but not homologous to immunoglobulins. They have a fundamentally different structure than immunoglobulin (Ig-based antibodies while still demonstrating high degrees of specificity and affinity. To test the functionality of VLRs as the antigen recognition domain of CARs, two VLR-CARs were created. One contained a VLR specific for a murine B cell leukemia and the other contained a VLR specific for the human T cell surface antigen, CD5. The CAR design consisted of the VLR sequence, myc-epitope tag, CD28 transmembrane domain, and intracellular CD3ζ signaling domain. We demonstrate proof of concept, including gene transfer, biosynthesis, cell surface localization, and effector cell activation for multiple VLR-CAR designs. Therefore, VLRs provide an alternative means of CAR-based cancer recognition.

  13. 'Multi-epitope-targeted' immune-specific therapy for a multiple sclerosis-like disease via engineered multi-epitope protein is superior to peptides.

    Directory of Open Access Journals (Sweden)

    Nathali Kaushansky

    Full Text Available Antigen-induced peripheral tolerance is potentially one of the most efficient and specific therapeutic approaches for autoimmune diseases. Although highly effective in animal models, antigen-based strategies have not yet been translated into practicable human therapy, and several clinical trials using a single antigen or peptidic-epitope in multiple sclerosis (MS yielded disappointing results. In these clinical trials, however, the apparent complexity and dynamics of the pathogenic autoimmunity associated with MS, which result from the multiplicity of potential target antigens and "epitope spread", have not been sufficiently considered. Thus, targeting pathogenic T-cells reactive against a single antigen/epitope is unlikely to be sufficient; to be effective, immunospecific therapy to MS should logically neutralize concomitantly T-cells reactive against as many major target antigens/epitopes as possible. We investigated such "multi-epitope-targeting" approach in murine experimental autoimmune encephalomyelitis (EAE associated with a single ("classical" or multiple ("complex" anti-myelin autoreactivities, using cocktail of different encephalitogenic peptides vis-a-vis artificial multi-epitope-protein (designated Y-MSPc encompassing rationally selected MS-relevant epitopes of five major myelin antigens, as "multi-epitope-targeting" agents. Y-MSPc was superior to peptide(s in concomitantly downregulating pathogenic T-cells reactive against multiple myelin antigens/epitopes, via inducing more effective, longer lasting peripheral regulatory mechanisms (cytokine shift, anergy, and Foxp3+ CTLA4+ regulatory T-cells. Y-MSPc was also consistently more effective than the disease-inducing single peptide or peptide cocktail, not only in suppressing the development of "classical" or "complex EAE" or ameliorating ongoing disease, but most importantly, in reversing chronic EAE. Overall, our data emphasize that a "multi-epitope-targeting" strategy is required for

  14. Plasmodium berghei: immunosuppression of the cell-mediated immune response induced by nonviable antigenic preparations

    International Nuclear Information System (INIS)

    Gross, A.; Frankenburg, S.

    1989-01-01

    In this work, plasmodial antigens were examined for their ability to suppress the cellular immune response during lethal Plasmodium berghei infection. Splenic enlargement and the number and function of white spleen cells were assessed after injection of normal mice with irradiated parasitized erythrocytes (IPE) or with parasitized erythrocytes (PE) membranes. Both IPE and PE membranes caused splenomegaly and an increase in the number of splenic white cells with concurrent alteration of the relative proportions of T cells and macrophages. The percentage of T lymphocytes was fractionally diminished, but there was a marked increase in Lyt 2.2 positive (suppressor and cytotoxic) T subsets and in the number of splenic macrophage precursors. The pathological enlargement of the spleen was induced by various plasma membrane-derived antigens containing both proteins and carbohydrates. Splenocytes of mice injected with liposomes containing deoxycholate-treated PE or PE fractions showed both diminished interleukin 2 production and a decreased response to mitogen. It appears that some of the changes in the cellular immune response during P. berghei infection are a consequence of the massive provision of a wide spectrum of antigens, capable of suppressing the immune response. Thus, it may be appropriate to evaluate the possible negative effect of parasite epitopes that are candidates for vaccine

  15. Co-delivery of antigen and IL-12 by Venezuelan equine encephalitis virus replicon particles enhances antigen-specific immune responses and anti-tumor effects

    Science.gov (United States)

    Osada, Takuya; Berglund, Peter; Morse, Michael A.; Hubby, Bolyn; Lewis, Whitney; Niedzwiecki, Donna; Hobeika, Amy; Burnett, Bruce; Devi, Gayathri R.; Clay, Timothy M.; Smith, Jonathan; Lyerly, H. Kim

    2013-01-01

    We recently demonstrated that Venezuelan equine encephalitis (VEE) virus-based replicon particles (VRP) encoding tumor antigens could break tolerance in the immunomodulatory environment of advanced cancer. We hypothesized that local injection of VRP expressing Interleukin-12 (IL-12) at the site of injections of VRP-based cancer vaccines would enhance the tumor-antigen-specific T cell and antibody responses and anti-tumor efficacy. Mice were immunized with VRP encoding the human tumor-associated antigen, carcinoembryonic antigen (CEA) (VRP-CEA(6D)) and VRP-IL-12 was also administered at the same site or at a distant location. CEA-specific T cell and antibody responses were measured. To determine antitumor activity, mice were implanted with MC38-CEA-2 cells and immunized with VRP-CEA with and without VRP-IL-12 and tumor growth and mouse survival were measured. VRP-IL-12 greatly enhanced CEA-specific T cell and antibody responses when combined with VRP-CEA(6D) vaccination. VRP IL-12 was superior to IL-12 protein at enhancing immune responses. Vaccination with VRP-CEA(6D) plus VRP-IL-12 was superior to VRP-CEA(6D) or VRP-IL-12 alone in inducing anti-tumor activity and prolonging survival in tumor-bearing mice. Importantly, local injection of VRP-IL-12 at the VRP-CEA(6D) injection site provided more potent activation of CEA-specific immune responses than VRP-IL-12 injected at a distant site from the VRP-CEA injections. Together, this study shows that VRP-IL-12 enhances vaccination with VRP-CEA(6D) and was more effective at activating CEA-specific T cell responses when locally expressed at the vaccine site. Clinical trials evaluating the adjuvant effect of VRP-IL-12 at enhancing the immunogenicity of cancer vaccines are warranted. PMID:22488274

  16. 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

  17. 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

  18. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans.

    Directory of Open Access Journals (Sweden)

    Johnny Vlaminck

    2016-12-01

    Full Text Available The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential.Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12 that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively and specificity (95.5% and 90.0% in pigs and humans, respectively.These findings show the presence of a highly stage specific, glycolipid-like component (As12 that is actively secreted by infectious Ascaris larvae and which acts as a major antibody target in infected humans and pigs.

  19. Cell-mediated immune response of synovial fluid lymphocytes to ureaplasma antigen in Reiter's syndrome

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    Pavlica Ljiljana

    2003-01-01

    Full Text Available INTRODUCTION Reiter's syndrome (RS is an seronegative arthritis that occurs after urogenital or enteric infection which in addition with occular and/or mucocutaneous manifestations presents complete form of disease. According to previous understanding arthritis in the RS is the reactive one, which means that it is impossible to isolate its causative agent. However, there are the more and more authors suggesting that arthritis in the urogenital form of disease is caused by the infective agent in the affected joint. This suggestion is based on numerous studies on the presence of Chlmaydia trachomatis and Ureaplasma urealyticum in the inflamed joint by using new diagnostic methods in molecular biology published in the recent literature [1-3]. Besides, numerous studies of the humoral and cell-mediated immune response to "triggering" bacteria in the affected joint have supported previous suggestions [4-7]. Aim of the study was to determine whether synovial fluid T-cells specifically recognize the "triggering" bacteria presumably responsible for the Reiter's syndrome. METHOD The 3H-thymidine uptake procedure for measuring lymphocyte responses was applied to lymphocytes derived concurrently from synovial fluid (SF and from peripheral blood (PB [8]. Ureaplasma antigen and mitogen PHA stimulated lymphocytes in 24 RS patients (24 PB samples, 9 SF samples and the results were compared with those found in 10 patients with rheumatoid arthritis (RA (10 PB samples, 5 SF samples. Preparation of ureaplasma antigen. Ureaplasma was cultured on cell-free liquid medium [9]. Sample of 8 ml was heat-inactivated for 15 minutes at 601C and permanently stirred with magnetic mixer. The sample was centrifuged at 2000 x g for 40 minutes and than deposits carefully carried to other sterile glass tubes (Corex and recentrifuged at 9000 x g for 30 minutes. The deposit was washed 3 times in sterile 0.9% NaCl, and final sediment was resuspended in 1.2 ml sterile 0.9% Na

  20. An experimental protocol for the establishment of dogs with long-term cellular immune reactions to Leishmania antigens

    Directory of Open Access Journals (Sweden)

    Márcia Cristina Aquino Teixeira

    2011-03-01

    Full Text Available Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.

  1. Immune Regulation by Self-Recognition

    DEFF Research Database (Denmark)

    Andersen, Mads Hald

    2015-01-01

    Circulating T cells that specifically target normal self-proteins expressed by regulatory immune cells were first described in patients with cancer, but can also be detected in healthy individuals. The adaptive immune system is distinguished for its ability to differentiate between self......-antigens and foreign antigens. Thus, it was remarkable to discover T cells that apparently lacked tolerance to important self-proteins, eg, IDO, PD-L1, and FoxP3, expressed in regulatory immune cells. The ability of self-reactive T cells to react to and eliminate regulatory immune cells can influence general immune...... reactions. This suggests that they may be involved in immune homeostasis. It is here proposed that these T cells should be termed antiregulatory T cells (anti-Tregs). The role of anti-Tregs in immune-regulatory networks may be diverse. For example, pro-inflammatory self-reactive T cells that react...

  2. Immunization with PIII, a fraction of Schistosoma mansoni soluble adult worm antigenic preparation, affects nitric oxide production by murine spleen cells

    Directory of Open Access Journals (Sweden)

    Diana Magalhães de Oliveira

    1998-01-01

    Full Text Available Nitric oxide (NO is an important effector molecule involved in immune regulation and defense. NO produced by cytokine-activated macrophages was reported to be cytotoxic against the helminth Schistosoma mansoni. Identification and characterization of S. mansoni antigens that can provide protective immunity is crucial for understanding the complex immunoregulatory events that modulate the immune response in schistosomiasis. It is, then, essential to have available defined, purified parasite antigens. Previous work by our laboratory identified a fraction of S. mansoni soluble adult worm antigenic preparation (SWAP, named PIII, able to elicit significant in vitro cell proliferation and at the same time lower in vitro and in vivo granuloma formation when compared either to SEA (soluble egg antigen or to SWAP. In the present work we report the effect of different in vivo trials with mice on their spleen cells ability to produce NO. We demonstrate that PIII-immunization is able to significantly increase NO production by spleen cells after in vitro stimulation with LPS. These data suggest a possible role for NO on the protective immunity induced by PIII.

  3. Risk factors for increased immune reconstitution in response to Mycobacterium tuberculosis antigens in tuberculosis HIV-infected, antiretroviral-naïve patients.

    Science.gov (United States)

    da Silva, Tatiana Pereira; Giacoia-Gripp, Carmem Beatriz Wagner; Schmaltz, Carolina A; Sant'Anna, Flavia Marinho; Saad, Maria Helena; Matos, Juliana Arruda de; de Lima E Silva, Julio Castro Alves; Rolla, Valeria Cavalcanti; Morgado, Mariza Gonçalves

    2017-09-06

    Little is known regarding the restoration of the specific immune response after combined antiretroviral therapy (cART) and anti-tuberculosis (TB) therapy introduction among TB-HIV patients. In this study, we examined the immune response of TB-HIV patients to Mycobacterium tuberculosis (Mtb) antigens to evaluate the response dynamics to different antigens over time. Moreover, we also evaluated the influence of two different doses of efavirenz and the factors associated with immune reconstitution. This is a longitudinal study nested in a clinical trial, where cART was initiated during the baseline visit (D0), which occurred 30 ± 10 days after the introduction of anti-TB therapy. Follow-up visits were performed at 30, 60, 90 and 180 days after cART initiation. The production of IFN-γ upon in vitro stimulation with Mtb antigens purified protein derivative (PPD), ESAT-6 and 38 kDa/CFP-10 using ELISpot was examined at baseline and follow-up visits. Sixty-one patients, all ART-naïve, were selected and included in the immune reconstitution analysis; seven (11.5%) developed Immune Reconstitution Inflammatory Syndrome (IRIS). The Mtb specific immune response was higher for the PPD antigen followed by 38 kDa/CFP-10 and increased in the first 60 days after cART initiation. In multivariate analysis, the variables independently associated with increased IFN-γ production in response to PPD antigen were CD4 + T cell counts tuberculosis, 800 mg efavirenz dose and follow-up CD4 + T cell counts. Moreover, the factors associated with the production of IFN-γ in response to 38 kDa/CFP-10 were detectable HIV viral load (VL) and CD4 + T cell counts at follow-up visits of ≥200 cells/mm 3 . These findings highlight the differences in immune response according to the specificity of the Mtb antigen, which contributes to a better understanding of TB-HIV immunopathogenesis. IFN-γ production elicited by PPD and 38 kDa/CFP-10 antigens have a greater magnitude compared to ESAT-6

  4. Evasion of adaptive and innate immune response mechanisms by γ-herpesviruses

    Science.gov (United States)

    Feng, Pinghui; Moses, Ashlee; Früh, Klaus

    2015-01-01

    γ-Herpesviral immune evasion mechanisms are optimized to support the acute, lytic and the longterm, latent phase of infection. During acute infection, specific immune modulatory proteins limit, but also exploit, the antiviral activities of cell intrinsic innate immune responses as well as those of innate and adaptive immune cells. During latent infection, a restricted gene expression program limits immune targeting and cis-acting mechanisms to reduce the antigen presentation as well as antigenicity of latency-associated proteins. Here, we will review recent progress in our understanding of γ-herpesviral immune evasion strategies. PMID:23735334

  5. 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.

  6. Immunizing Patients With Metastatic Melanoma Using Recombinant Adenoviruses Encoding MART-1 or gp100 Melanoma Antigens

    Science.gov (United States)

    Rosenberg, Steven A.; Zhai, Yifan; Yang, James C.; Schwartzentruber, Douglas J.; Hwu, Patrick; Marincola, Francesco M.; Topalian, Suzanne L.; Restifo, Nicholas P.; Seipp, Claudia A.; Einhorn, Jan H.; Roberts, Bruce; White, Donald E.

    2008-01-01

    Background: The characterization of the genes encoding melanoma-associated antigens MART-1 or gp100, recognized by T cells, has opened new possibilities for the development of immunization strategies for patients with metastatic melanoma. With the use of recombinant adenoviruses expressing either MART-1 or gp100 to immunize patients with metastatic melanoma, we evaluated the safety, immunologic, and potential therapeutic aspects of these immunizations. Methods: In phase I studies, 54 patients received escalating doses (between 107 and 1011 plaque-forming units) of recombinant adenovirus encoding either MART-1 or gp100 melanoma antigen administered either alone or followed by the administration of interleukin 2 (IL-2). The immunologic impact of these immunizations on the development of cellular and antibody reactivity was assayed. Results: Recombinant adenoviruses expressing MART-1 or gp100 were safely administered. One of 16 patients with metastatic melanoma receiving the recombinant adenovirus MART-1 alone experienced a complete response. Other patients achieved objective responses, but they had received IL-2 along with an adenovirus, and their responses could be attributed to the cytokine. Immunologic assays showed no consistent immunization to the MART-1 or gp100 transgenes expressed by the recombinant adenoviruses. High levels of neutralizing antibody were found in the pretreatment sera of the patients. Conclusions: High doses of recombinant adenoviruses could be safely administered to cancer patients. High levels of neutralizing antibody present in patients' sera prior to treatment may have impaired the ability of these viruses to immunize patients against melanoma antigens. PMID:9862627

  7. 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.

  8. Small organic compounds enhance antigen loading of class II major histocompatibility complex proteins by targeting the polymorphic P1 pocket

    DEFF Research Database (Denmark)

    Höpner, Sabine; Dickhaut, Katharina; Hofstätter, Maria

    2006-01-01

    the peptide loading rate. The effect was evident only for an allelic subset and strictly correlated with the presence of glycine at the dimorphic position beta86 of the HLA-DR molecule. The residue forms the floor of the conserved pocket P1, located in the peptide binding site of MHC molecule. Apparently......, transient occupation of this pocket by the organic compound stabilizes the peptide-receptive conformation permitting rapid antigen loading. This interaction appeared restricted to the larger Gly(beta86) pocket and allowed striking enhancements of T cell responses for antigens presented by these "adamantyl......-susceptible" MHC molecules. As catalysts of antigen loading, compounds targeting P1 may be useful molecular tools to amplify the immune response. The observation, however, that the ligand repertoire can be affected through polymorphic sites form the outside may also imply that environmental factors could induce...

  9. NLRC5/MHC class I transactivator is a target for immune evasion in cancer.

    Science.gov (United States)

    Yoshihama, Sayuri; Roszik, Jason; Downs, Isaac; Meissner, Torsten B; Vijayan, Saptha; Chapuy, Bjoern; Sidiq, Tabasum; Shipp, Margaret A; Lizee, Gregory A; Kobayashi, Koichi S

    2016-05-24

    Cancer cells develop under immune surveillance, thus necessitating immune escape for successful growth. Loss of MHC class I expression provides a key immune evasion strategy in many cancers, although the molecular mechanisms remain elusive. MHC class I transactivator (CITA), known as "NLRC5" [NOD-like receptor (NLR) family, caspase recruitment (CARD) domain containing 5], has recently been identified as a critical transcriptional coactivator of MHC class I gene expression. Here we show that the MHC class I transactivation pathway mediated by CITA/NLRC5 constitutes a target for cancer immune evasion. In all the 21 tumor types we examined, NLRC5 expression was highly correlated with the expression of MHC class I, with cytotoxic T-cell markers, and with genes in the MHC class I antigen-presentation pathway, including LMP2/LMP7, TAP1, and β2-microglobulin. Epigenetic and genetic alterations in cancers, including promoter methylation, copy number loss, and somatic mutations, were most prevalent in NLRC5 among all MHC class I-related genes and were associated with the impaired expression of components of the MHC class I pathway. Strikingly, NLRC5 expression was significantly associated with the activation of CD8(+) cytotoxic T cells and patient survival in multiple cancer types. Thus, NLRC5 constitutes a novel prognostic biomarker and potential therapeutic target of cancers.

  10. Inflammatory and immune responses in the cochlea: potential therapeutic targets for sensorineural hearing loss

    Directory of Open Access Journals (Sweden)

    Masato eFujioka

    2014-12-01

    Full Text Available The inner ear was previously assumed to be an immune-privileged organ due to the existence of its tight junction-based blood-labyrinth barrier. However, studies performed during the past decade revealed that the mesenchymal region of the cochlea, including its lateral wall, is a common site of inflammation. Neutrophils do not enter this region, which is consistent with the old dogma; however, bone marrow-derived resident macrophages are always present in the spiral ligament of the lateral wall and are activated in response to various types of insults, including noise exposure, ischemia, mitochondrial damage and surgical stress. Recent studies have also revealed another type of immune cell, called perivascular melanocyte-like macrophages (PVM/Ms, in the stria vascularis. These dedicated antigen-presenting cells also control vascular contraction and permeability. This review discusses a series of reports regarding inflammatory/immune cells in the cochlear lateral wall, the pathways involved in cochlear damage and their potential as therapeutic targets.

  11. A platform to screen for C-type lectin receptor-binding carbohydrates and their potential for cell-specific targeting and immune modulation.

    Science.gov (United States)

    Maglinao, Maha; Eriksson, Magdalena; Schlegel, Mark K; Zimmermann, Stephanie; Johannssen, Timo; Götze, Sebastian; Seeberger, Peter H; Lepenies, Bernd

    2014-02-10

    Myeloid C-type lectin receptors (CLRs) in innate immunity represent a superfamily of pattern recognition receptors that recognize carbohydrate structures on pathogens and self-antigens. The primary interaction of an antigen-presenting cell and a pathogen shapes the following immune response. Therefore, the identification of CLR ligands that can either enhance or modulate the immune response is of interest. We have developed a screening platform based on glycan arrays to identify immune modulatory carbohydrate ligands of CLRs. A comprehensive library of CLRs was expressed by fusing the extracellular part of each respective CLR, the part containing the carbohydrate-recognition domain (CRD), to the Fc fragment of human IgG1 molecules. CLR-Fc fusion proteins display the CRD in a dimeric form, are properly glycosylated, and can be detected by a secondary antibody with a conjugated fluorophore. Thus, they are valuable tools for high-throughput screening. We were able to identify novel carbohydrate binders of CLRs using the glycan array technology. These CLR-binding carbohydrates were then covalently attached to the model antigen ovalbumin. The ovalbumin neoglycoconjugates were used in a dendritic cell/T cell co-culture assay to stimulate transgenic T cells in vitro. In addition, mice were immunized with these conjugates to analyze the immune modulatory properties of the CLR ligands in vivo. The CLR ligands induced an increased Th1 cytokine production in vitro and modulated the humoral response in vivo. The platform described here allows for the identification of CLR ligands, as well as the evaluation of each ligand's cell-specific targeting and immune modulatory properties. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Glycan-mediated modification of the immune response

    DEFF Research Database (Denmark)

    Madsen, Caroline B; Pedersen, Anders E; Wandall, Hans H

    2013-01-01

    Aberrantly glycosylated tumor antigens represent promising targets for the development of anti-cancer vaccines, yet how glycans influence immune responses is poorly understood. Recent studies have demonstrated that GalNAc-glycosylation enhances antigen uptake by dendritic cells as well as CD4(+) T......-cell and humoral responses, but prevents CD8(+) T-cell activation. Here, we briefly discuss the relevance of glycans as candidate targets for anti-cancer vaccines....

  13. An endogenous nanomineral chaperones luminal antigen and peptidoglycan to intestinal immune cells.

    Science.gov (United States)

    Powell, Jonathan J; Thomas-McKay, Emma; Thoree, Vinay; Robertson, Jack; Hewitt, Rachel E; Skepper, Jeremy N; Brown, Andy; Hernandez-Garrido, Juan Carlos; Midgley, Paul A; Gomez-Morilla, Inmaculada; Grime, Geoffrey W; Kirkby, Karen J; Mabbott, Neil A; Donaldson, David S; Williams, Ifor R; Rios, Daniel; Girardin, Stephen E; Haas, Carolin T; Bruggraber, Sylvaine F A; Laman, Jon D; Tanriver, Yakup; Lombardi, Giovanna; Lechler, Robert; Thompson, Richard P H; Pele, Laetitia C

    2015-04-01

    In humans and other mammals it is known that calcium and phosphate ions are secreted from the distal small intestine into the lumen. However, why this secretion occurs is unclear. Here, we show that the process leads to the formation of amorphous magnesium-substituted calcium phosphate nanoparticles that trap soluble macromolecules, such as bacterial peptidoglycan and orally fed protein antigens, in the lumen and transport them to immune cells of the intestinal tissue. The macromolecule-containing nanoparticles utilize epithelial M cells to enter Peyer's patches, small areas of the intestine concentrated with particle-scavenging immune cells. In wild-type mice, intestinal immune cells containing these naturally formed nanoparticles expressed the immune tolerance-associated molecule 'programmed death-ligand 1', whereas in NOD1/2 double knockout mice, which cannot recognize peptidoglycan, programmed death-ligand 1 was undetected. Our results explain a role for constitutively formed calcium phosphate nanoparticles in the gut lumen and show how this helps to shape intestinal immune homeostasis.

  14. An endogenous nanomineral chaperones luminal antigen and peptidoglycan to intestinal immune cells

    Science.gov (United States)

    Powell, Jonathan J.; Thomas-McKay, Emma; Thoree, Vinay; Robertson, Jack; Hewitt, Rachel E.; Skepper, Jeremy N.; Brown, Andy; Hernandez-Garrido, Juan Carlos; Midgley, Paul A.; Gomez-Morilla, Inmaculada; Grime, Geoffrey W.; Kirkby, Karen J.; Mabbott, Neil A.; Donaldson, David S.; Williams, Ifor R.; Rios, Daniel; Girardin, Stephen E.; Haas, Carolin T.; Bruggraber, Sylvaine F. A.; Laman, Jon D.; Tanriver, Yakup; Lombardi, Giovanna; Lechler, Robert; Thompson, Richard P. H.; Pele, Laetitia C.

    2015-05-01

    In humans and other mammals it is known that calcium and phosphate ions are secreted from the distal small intestine into the lumen. However, why this secretion occurs is unclear. Here, we show that the process leads to the formation of amorphous magnesium-substituted calcium phosphate nanoparticles that trap soluble macromolecules, such as bacterial peptidoglycan and orally fed protein antigens, in the lumen and transport them to immune cells of the intestinal tissue. The macromolecule-containing nanoparticles utilize epithelial M cells to enter Peyer's patches, small areas of the intestine concentrated with particle-scavenging immune cells. In wild-type mice, intestinal immune cells containing these naturally formed nanoparticles expressed the immune tolerance-associated molecule ‘programmed death-ligand 1’, whereas in NOD1/2 double knockout mice, which cannot recognize peptidoglycan, programmed death-ligand 1 was undetected. Our results explain a role for constitutively formed calcium phosphate nanoparticles in the gut lumen and show how this helps to shape intestinal immune homeostasis.

  15. Antigenic characterization of small, round-structured viruses by immune electron microscopy.

    Science.gov (United States)

    Okada, S; Sekine, S; Ando, T; Hayashi, Y; Murao, M; Yabuuchi, K; Miki, T; Ohashi, M

    1990-06-01

    Small, round-structured viruses (SRSVs) detected from nonbacterial gastroenteritis outbreaks in Tokyo and Saitama Prefecture, Japan, during the period from 1977 to 1988 were tentatively classified into nine antigenic patterns from SRSV-1 (S-1) to SRSV-9 (S-9) by cross-immune electron microscopy (IEM). S-1 and S-2 appeared pattern specific, while S-3 to S-9, distinguishable from each other in their reactivity, appeared somewhat antigenically related. Their antigenic relatedness to the Norwal, Hawaii, and Otofuke agents was also examined by IEM by using antisera to these agents. S-3 appeared most closely related to the Norwalk agent. S-4 and S-5 were related to the Norwalk agent and, presumably, were distantly related to the Hawaii and Otofuke agents. S-6 and S-7 were related to the Hawaii and Otofuke agents. S-8 and S-9 were related to the Otofuke agent and, presumably, were distantly related to the Hawaii agent. The prevalence of each antigenic pattern in 38 outbreaks was examined: S-8 was implicated in 24% of the outbreaks S-5 in 16%, S-4 in 13%, S-9 in 13%, S-6 in 11%, and others in 5%.

  16. Distinct effects on diversifying selection by two mechanisms of immunity against Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Yuan Li

    Full Text Available Antigenic variation to evade host immunity has long been assumed to be a driving force of diversifying selection in pathogens. Colonization by Streptococcus pneumoniae, which is central to the organism's transmission and therefore evolution, is limited by two arms of the immune system: antibody- and T cell- mediated immunity. In particular, the effector activity of CD4(+ T(H17 cell mediated immunity has been shown to act in trans, clearing co-colonizing pneumococci that do not bear the relevant antigen. It is thus unclear whether T(H17 cell immunity allows benefit of antigenic variation and contributes to diversifying selection. Here we show that antigen-specific CD4(+ T(H17 cell immunity almost equally reduces colonization by both an antigen-positive strain and a co-colonized, antigen-negative strain in a mouse model of pneumococcal carriage, thus potentially minimizing the advantage of escape from this type of immunity. Using a proteomic screening approach, we identified a list of candidate human CD4(+ T(H17 cell antigens. Using this list and a previously published list of pneumococcal Antibody antigens, we bioinformatically assessed the signals of diversifying selection among the identified antigens compared to non-antigens. We found that Antibody antigen genes were significantly more likely to be under diversifying selection than the T(H17 cell antigen genes, which were indistinguishable from non-antigens. Within the Antibody antigens, epitopes recognized by human antibodies showed stronger evidence of diversifying selection. Taken together, the data suggest that T(H17 cell-mediated immunity, one form of T cell immunity that is important to limit carriage of antigen-positive pneumococcus, favors little diversifying selection in the targeted antigen. The results could provide new insight into pneumococcal vaccine design.

  17. Whole blood assay to access T cell-immune responses to Mycobacterium tuberculosis antigens in healthy Brazilian individuals

    Directory of Open Access Journals (Sweden)

    Paulo RZ Antas

    2004-02-01

    Full Text Available The production of interferon gamma (IFNgamma guarantees effective T cell-mediated immunity against Mycobacterium tuberculosis infection. In the present study, we simply compare the in vitro immune responses to Mycobacterium antigens in terms of IFNg production in a total of 10 healthy Brazilian volunteers. Whole blood and mononuclear cells were cultivated in parallel with PPD, Ag85B, and M. bovis hsp65, and five-days supernatants were harvested for cytokine detection by ELISA. The inter-assay result was that the overall profile of agreement in response to antigens was highly correlated (r² = 0.9266; p = 0.0102. Potential analysis is in current progress to dictate the usefulness of this method to access the immune responses also in tuberculosis patients and its contacts.

  18. A novel IgE antibody targeting the prostate-specific antigen as a potential prostate cancer therapy

    International Nuclear Information System (INIS)

    Daniels-Wells, Tracy R; Nicodemus, Christopher F; Penichet, Manuel L; Helguera, Gustavo; Leuchter, Richard K; Quintero, Rafaela; Kozman, Maggie; Rodríguez, José A; Ortiz-Sánchez, Elizabeth; Martínez-Maza, Otoniel; Schultes, Birgit C

    2013-01-01

    Prostate cancer (PCa) is the second leading cause of cancer deaths in men in the United States. The prostate-specific antigen (PSA), often found at high levels in the serum of PCa patients, has been used as a marker for PCa detection and as a target of immunotherapy. The murine IgG1 monoclonal antibody AR47.47, specific for human PSA, has been shown to enhance antigen presentation by human dendritic cells and induce both CD4 and CD8 T-cell activation when complexed with PSA. In this study, we explored the properties of a novel mouse/human chimeric anti-PSA IgE containing the variable regions of AR47.47 as a potential therapy for PCa. Our goal was to take advantage of the unique properties of IgE in order to trigger immune activation against PCa. Binding characteristics of the antibody were determined by ELISA and flow cytometry. In vitro degranulation was determined by the release of β-hexosaminidase from effector cells. In vivo degranulation was monitored in human FcεRIα transgenic mice using the passive cutaneous anaphylaxis assay. These mice were also used for a vaccination study to determine the in vivo anti-cancer effects of this antibody. Significant differences in survival were determined using the Log Rank test. In vitro T-cell activation was studied using human dendritic cells and autologous T cells. The anti-PSA IgE, expressed in murine myeloma cells, is properly assembled and secreted, and binds the antigen and FcεRI. In addition, this antibody is capable of triggering effector cell degranulation in vitro and in vivo when artificially cross-linked, but not in the presence of the natural soluble antigen, suggesting that such an interaction will not trigger systemic anaphylaxis. Importantly, the anti-PSA IgE combined with PSA also triggers immune activation in vitro and in vivo and significantly prolongs the survival of human FcεRIα transgenic mice challenged with PSA-expressing tumors in a prophylactic vaccination setting. The anti-PSA IgE exhibits

  19. Recent Advances in Aptamers Targeting Immune System.

    Science.gov (United States)

    Hu, Piao-Ping

    2017-02-01

    The immune system plays important role in protecting the organism by recognizing non-self molecules from pathogen such as bacteria, parasitic worms, and viruses. When the balance of the host defense system is disturbed, immunodeficiency, autoimmunity, and inflammation occur. Nucleic acid aptamers are short single-stranded DNA (ssDNA) or RNA ligands that interact with complementary molecules with high specificity and affinity. Aptamers that target the molecules involved in immune system to modulate their function have great potential to be explored as new diagnostic and therapeutic agents for immune disorders. This review summarizes recent advances in the development of aptamers targeting immune system. The selection of aptamers with superior chemical and biological characteristics will facilitate their application in the diagnosis and treatment of immune disorders.

  20. Prostate Specific Membrane Antigen (PSMA) Targeted Bio-orthogonal Therapy for Metastatic Prostate Cancer

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-16-1-0595 TITLE: Prostate-Specific Membrane Antigen (PSMA) Targeted Bio -orthogonal Therapy for Metastatic Prostate Cancer...Sep 2016 - 14 Sep 2017 4. TITLE AND SUBTITLE Prostate-Specific Membrane Antigen (PSMA) Targeted Bio -orthogonal Therapy for Metastatic Prostate

  1. Immunization against HTLV-I with chitosan and tri-methylchitosan nanoparticles loaded with recombinant env23 and env13 antigens of envelope protein gp46.

    Science.gov (United States)

    Amirnasr, Maryam; Fallah Tafti, Tannan; Sankian, Mojtaba; Rezaei, Abdorrahim; Tafaghodi, Mohsen

    2016-08-01

    To prevent the spread of HTLV-I (Human T-lymphotropic virus type 1), a safe and effective vaccine is required. To increase immune responses against the peptide antigens can be potentiated with polymer-based nanoparticles, like chitosan (CHT) and trimethylchitosan (TMC), as delivery system/adjuvant. CHT and TMC nanoparticles loaded with recombinant proteins (env23 & env13) of gp46 were prepared by direct coating of antigens with positively charged polymers. The size of CHT and TMC nanoparticles (NPs) loaded with each antigen was about 400 nm. The physical stability of NPs was followed for 4 weeks. Both formulations showed to be stable for about 15 days. The immunogenicity of NPs loaded with antigens was studied after nasal and subcutaneous immunization in mice. Three immunizations (7.5 μg antigen) were performed with 2 weeks intervals. Two weeks after the last booster dose, sera IgG subtypes were measured. After subcutaneous administration, for both nanoparticulate antigens, serum IgG1 and IgGtotal levels were higher than antigen solution (P nanoparticles showed good immunoadjuvant potential. Env23 antigen was a better candidate for vaccination against HTLV-I, as it induced higher cellular immune responses, compared with env13. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Polymer nanoparticles for cross-presentation of exogenous antigens and enhanced cytotoxic T-lymphocyte immune response

    Directory of Open Access Journals (Sweden)

    Song C

    2016-08-01

    Full Text Available Chanyoung Song,* Young-Woock Noh,* Yong Taik Lim SKKU Advanced Institute of Nanotechnology (SAINT, School of Chemical Engineering, Sungkyunkwan University, Suwon, South Korea *These authors contributed equally to this work Abstract: Effective induction of an antigen-specific cytotoxic T lymphocyte (CTL immune response is one of the key goals of cancer immunotherapy. We report the design and fabrication of polyethylenimine (PEI-coated polymer nanoparticles (NPs as efficient antigen-delivery carriers that can induce antigen cross-presentation and a strong CTL response. After synthesis of poly(d,l-lactide-co-glycolide (PLGA NPs containing ovalbumin (OVA by the double-emulsion solvent-evaporation method, cationic-charged PLGA NPs were generated by coating them with PEI. In a methyl tetrazolium salt assay, no discernible cytotoxic effect of PEI-coated PLGA (OVA NPs was observed. The capacity and mechanism of PEI-coated PLGA (OVA NPs for antigen delivery and cross-presentation on dendritic cells (DCs were determined by fluorescence microscopy and flow cytometry. PEI-coated PLGA (OVA NPs were internalized efficiently via phagocytosis or macropinocytosis in DCs and induced efficient cross-presentation of the antigen on MHC class I molecules via both endosome escape and a lysosomal processing mechanism. The DCs treated with PEI-coated PLGA (OVA NPs induced a release of IL-2 cytokine from OVA-specific CD8-OVA1.3 T cells more efficiently than DCs treated with PLGA (OVA NPs. Therefore, the PEI-coated PLGA (OVA NPs can induce antigen cross-presentation and are expected to be used for induction of a strong CTL immune response and for efficient anticancer immunotherapy. Keywords: antigen delivery, dendritic cells, polymer NPs, vaccine, cross-presentation

  3. 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.

  4. Differences in the Antigens of Helicobacter pylori Strains Influence on the Innate Immune Response in the In Vitro Experiments

    Directory of Open Access Journals (Sweden)

    Miha Skvarc

    2014-01-01

    Full Text Available The immune response to Helicobacter pylori importantly determines the pathogenesis of infection as well as the success of antibiotic eradication of the bacteria. Strains of H. pylori were gathered from 14 patients who failed to eradicate H. pylori infection with antibiotics—therapy resistant strains (TRS—or from patients who were able to eradicate H. pylori infection—therapy susceptible strains (TSS. The THP-1 cells were stimulated with H. pylori antigens. Cathepsin X expression on THP-1 cells and concentration of cytokines in the supernatant of THP-1 cells were measured with a flow cytometer. TSS H. pylori antigens increased the proportion of cathepsin X positive cells compared to TRS H. pylori antigens. TSS H. pylori antigens induced higher secretion of IL-12 and IL-6 compared to TRS H. pylori antigens (P<0.001; 0.02. Polymyxin B, a lipid A inhibitor, lowered the secretion of IL-12 and IL-6 in TRS and TSS. We demonstrated a H. pylori strain-dependent cathepsin X and cytokine expression that can be associated with H. pylori resistance to eradication due to lack of effective immune response. Differences in lipid A of H. pylori might have an influence on the insufficient immune response, especially on phagocytosis.

  5. Solid nanoemulsion as antigen and immunopotentiator carrier for transcutaneous immunization.

    Science.gov (United States)

    Gogoll, Karsten; Stein, Pamela; Lee, K D; Arnold, Philipp; Peters, Tanja; Schild, Hansjörg; Radsak, Markus; Langguth, Peter

    2016-10-01

    Imiquimod, a toll-like receptor 7 (TLR7) agonist, is an active pharmaceutical ingredient (API) established for the topical treatment of several dermal cancerous and precancerous skin lesions. Within this work, the immunostimulatory effect of imiquimod is further exploited in a transcutaneous immunization (TCI) approach based on a solid nanoemulsion (SN) formulation. SN contains a combination of imiquimod with the model peptide antigen SIINFEKL as a novel approach to omit needle and syringe and optimize dermal antigen administration. Excipients including sucrose fatty acid esters and the pharmaceutically acceptable oils MCT (middle chain triglycerides), avocado oil, jojoba wax and squalene are high pressure homogenized together with the antigen SIINFEKL. Freeze drying was performed to eliminate water and to achieve spreadable properties of the formulation for dermal administration. The influence of the different oil components was assessed regarding in vitro drug permeation in a Franz diffusion cell model using a murine skin setup. In vivo performance in terms of cytotoxic T-cell response was assessed in a C57BL/6 mouse model. Whereas Aldara® cream contains imiquimod in a dissolved state, the SN formulations carry the active in a suspended state. This resulted in a reduction of imiquimod permeation across murine skin from the SN when compared to Aldara® cream. In spite of this permeation rate reduction, each SN induced an in vivo immune response by specific T-cell lysis. A stabilized solid nanosuspension containing squalene/tocopherol exhibited a significantly higher performance (p⩽0.05) in comparison with Aldara® cream. MCT based SN exerted an in vivo effect comparable to Aldara®. In conclusion, anhydrous highly dispersed vehicles containing imiquimod in a submicron particle size distribution can represent promising formulations for TCI. The choice of the oil component has a strong influence on SN performance, independent of in vitro drug permeation

  6. Carnauba wax nanoparticles enhance strong systemic and mucosal cellular and humoral immune responses to HIV-gp140 antigen.

    Science.gov (United States)

    Arias, Mauricio A; Loxley, Andrew; Eatmon, Christy; Van Roey, Griet; Fairhurst, David; Mitchnick, Mark; Dash, Philip; Cole, Tom; Wegmann, Frank; Sattentau, Quentin; Shattock, Robin

    2011-02-01

    Induction of humoral responses to HIV at mucosal compartments without inflammation is important for vaccine design. We developed charged wax nanoparticles that efficiently adsorb protein antigens and are internalized by DC in the absence of inflammation. HIV-gp140-adsorbed nanoparticles induced stronger in vitro T-cell proliferation responses than antigen alone. Such responses were greatly enhanced when antigen was co-adsorbed with TLR ligands. Immunogenicity studies in mice showed that intradermal vaccination with HIV-gp140 antigen-adsorbed nanoparticles induced high levels of specific IgG. Importantly, intranasal immunization with HIV-gp140-adsorbed nanoparticles greatly enhanced serum and vaginal IgG and IgA responses. Our results show that HIV-gp140-carrying wax nanoparticles can induce strong cellular/humoral immune responses without inflammation and may be of potential use as effective mucosal adjuvants for HIV vaccine candidates. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. An inducible transgenic mouse model for immune mediated hepatitis showing clearance of antigen expressing hepatocytes by CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Marcin Cebula

    Full Text Available The liver has the ability to prime immune responses against neo antigens provided upon infections. However, T cell immunity in liver is uniquely modulated by the complex tolerogenic property of this organ that has to also cope with foreign agents such as endotoxins or food antigens. In this respect, the nature of intrahepatic T cell responses remains to be fully characterized. To gain deeper insight into the mechanisms that regulate the CD8+ T cell responses in the liver, we established a novel OVA_X_CreER(T2 mouse model. Upon tamoxifen administration OVA antigen expression is observed in a fraction of hepatocytes, resulting in a mosaic expression pattern. To elucidate the cross-talk of CD8+ T cells with antigen-expressing hepatocytes, we adoptively transferred K(b/OVA257-264-specific OT-I T cells to OVA_X_CreER(T2 mice or generated triple transgenic OVA_X CreER(T2_X_OT-I mice. OT-I T cells become activated in OVA_X_CreER(T2 mice and induce an acute and transient hepatitis accompanied by liver damage. In OVA_X_CreER(T2_X_OT-I mice, OVA induction triggers an OT-I T cell mediated, fulminant hepatitis resulting in 50% mortality. Surviving mice manifest a long lasting hepatitis, and recover after 9 weeks. In these experimental settings, recovery from hepatitis correlates with a complete loss of OVA expression indicating efficient clearance of the antigen-expressing hepatocytes. Moreover, a relapse of hepatitis can be induced upon re-induction of cured OVA_X_CreER(T2_X_OT-I mice indicating absence of tolerogenic mechanisms. This pathogen-free, conditional mouse model has the advantage of tamoxifen inducible tissue specific antigen expression that reflects the heterogeneity of viral antigen expression and enables the study of intrahepatic immune responses to both de novo and persistent antigen. It allows following the course of intrahepatic immune responses: initiation, the acute phase and antigen clearance.

  8. Using network properties to evaluate targeted immunization algorithms

    Directory of Open Access Journals (Sweden)

    Bita Shams

    2014-09-01

    Full Text Available Immunization of complex network with minimal or limited budget is a challenging issue for research community. In spite of much literature in network immunization, no comprehensive research has been conducted for evaluation and comparison of immunization algorithms. In this paper, we propose an evaluation framework for immunization algorithms regarding available amount of vaccination resources, goal of immunization program, and time complexity. The evaluation framework is designed based on network topological metrics which is extensible to all epidemic spreading model. Exploiting evaluation framework on well-known targeted immunization algorithms shows that in general, immunization based on PageRank centrality outperforms other targeting strategies in various types of networks, whereas, closeness and eigenvector centrality exhibit the worst case performance.

  9. Ultraviolet light-induced suppression of antigen presentation

    International Nuclear Information System (INIS)

    Spellman, C.W.; Tomasi, T.B.

    1983-01-01

    Ultraviolet (UV) light irradiation of animals results in the development of specific T suppressor cells that inhibit antitumor immune responses. It is thought that suppression may arise as a consequence of altered antigen presentation by UV-irradiated epidermal cells. This hypothesis is based on evidence demonstrating that specific lymphoid tissues from UV-irradiated hosts exhibit impaired antigen-presenting function and that animals cannot be contact sensitized when antigens are applied to a UV-irradiated skin site. Langerhans cells of the skin are likely candidates as targets of UV-induced defects in antigen presentation as they bear Fc and C3b receptors, express Ia antigens, are of bone marrow origin, and are capable of presenting antigen in vitro. We speculate on the possible clinical usefulness of UV-induced tolerance to specific antigens such as those encountered in monoclonal antibody therapy and tissue transplantation

  10. Cell-permeable nanobodies for targeted immunolabelling and antigen manipulation in living cells.

    Science.gov (United States)

    Herce, Henry D; Schumacher, Dominik; Schneider, Anselm F L; Ludwig, Anne K; Mann, Florian A; Fillies, Marion; Kasper, Marc-André; Reinke, Stefan; Krause, Eberhard; Leonhardt, Heinrich; Cardoso, M Cristina; Hackenberger, Christian P R

    2017-08-01

    Functional antibody delivery in living cells would enable the labelling and manipulation of intracellular antigens, which constitutes a long-thought goal in cell biology and medicine. Here we present a modular strategy to create functional cell-permeable nanobodies capable of targeted labelling and manipulation of intracellular antigens in living cells. The cell-permeable nanobodies are formed by the site-specific attachment of intracellularly stable (or cleavable) cyclic arginine-rich cell-penetrating peptides to camelid-derived single-chain VHH antibody fragments. We used this strategy for the non-endocytic delivery of two recombinant nanobodies into living cells, which enabled the relocalization of the polymerase clamp PCNA (proliferating cell nuclear antigen) and tumour suppressor p53 to the nucleolus, and thereby allowed the detection of protein-protein interactions that involve these two proteins in living cells. Furthermore, cell-permeable nanobodies permitted the co-transport of therapeutically relevant proteins, such as Mecp2, into the cells. This technology constitutes a major step in the labelling, delivery and targeted manipulation of intracellular antigens. Ultimately, this approach opens the door towards immunostaining in living cells and the expansion of immunotherapies to intracellular antigen targets.

  11. Cell-permeable nanobodies for targeted immunolabelling and antigen manipulation in living cells

    Science.gov (United States)

    Herce, Henry D.; Schumacher, Dominik; Schneider, Anselm F. L.; Ludwig, Anne K.; Mann, Florian A.; Fillies, Marion; Kasper, Marc-André; Reinke, Stefan; Krause, Eberhard; Leonhardt, Heinrich; Cardoso, M. Cristina; Hackenberger, Christian P. R.

    2017-08-01

    Functional antibody delivery in living cells would enable the labelling and manipulation of intracellular antigens, which constitutes a long-thought goal in cell biology and medicine. Here we present a modular strategy to create functional cell-permeable nanobodies capable of targeted labelling and manipulation of intracellular antigens in living cells. The cell-permeable nanobodies are formed by the site-specific attachment of intracellularly stable (or cleavable) cyclic arginine-rich cell-penetrating peptides to camelid-derived single-chain VHH antibody fragments. We used this strategy for the non-endocytic delivery of two recombinant nanobodies into living cells, which enabled the relocalization of the polymerase clamp PCNA (proliferating cell nuclear antigen) and tumour suppressor p53 to the nucleolus, and thereby allowed the detection of protein-protein interactions that involve these two proteins in living cells. Furthermore, cell-permeable nanobodies permitted the co-transport of therapeutically relevant proteins, such as Mecp2, into the cells. This technology constitutes a major step in the labelling, delivery and targeted manipulation of intracellular antigens. Ultimately, this approach opens the door towards immunostaining in living cells and the expansion of immunotherapies to intracellular antigen targets.

  12. Strategies to Improve Vaccine Efficacy against Tuberculosis by Targeting Innate Immunity

    Directory of Open Access Journals (Sweden)

    Ulrich E. Schaible

    2017-12-01

    Full Text Available The global tuberculosis epidemic is the most common cause of death after infectious disease worldwide. Increasing numbers of infections with multi- and extensively drug-resistant variants of the Mycobacterium tuberculosis complex, resistant even to newly discovered and last resort antibiotics, highlight the urgent need for an efficient vaccine. The protective efficacy to pulmonary tuberculosis in adults of the only currently available vaccine, M. bovis BCG, is unsatisfactory and geographically diverse. More importantly, recent clinical studies on new vaccine candidates did not prove to be better than BCG, yet. Here, we propose and discuss novel strategies to improve efficacy of existing anti-tuberculosis vaccines. Modulation of innate immune responses upon vaccination already provided promising results in animal models of tuberculosis. For instance, neutrophils have been shown to influence vaccine efficacy, both, positively and negatively, and stimulate specific antibody secretion. Modulating immune regulatory properties after vaccination such as induction of different types of innate immune cell death, myeloid-derived suppressor or regulatory T cells, production of anti-inflammatory cytokines such as IL-10 may have beneficial effects on protection efficacy. Incorporation of lipid antigens presented via CD1 molecules to T cells have been discussed as a way to enhance vaccine efficacy. Finally, concepts of dendritic cell-based immunotherapies or training the innate immune memory may be exploitable for future vaccination strategies against tuberculosis. In this review, we put a spotlight on host immune networks as potential targets to boost protection by old and new tuberculosis vaccines.

  13. Immunization with FSHβ fusion protein antigen prevents bone loss in a rat ovariectomy-induced osteoporosis model

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Wenxin; Yan, Xingrong; Du, Huicong; Cui, Jihong; Li, Liwen, E-mail: liven@nwu.edu.cn; Chen, Fulin, E-mail: chenfl@nwu.edu.cn

    2013-05-03

    Highlights: •A GST-FSH fusion protein was successfully expressed in E. coli. •Immunization with GST-FSH antigen can raise high-titer anti-FSH polyclonal sera. •Anti-FSH polyclonal sera can neutralize osteoclastogenic effect of FSH in vitro. •FSH immunization can prevent bone loss in a rat osteoporosis model. -- Abstract: Osteoporosis, a metabolic bone disease, threatens postmenopausal women globally. Hormone replacement therapy (HTR), especially estrogen replacement therapy (ERT), is used widely in the clinic because it has been generally accepted that postmenopausal osteoporosis is caused by estrogen deficiency. However, hypogonadal α and β estrogen receptor null mice were only mildly osteopenic, and mice with either receptor deleted had normal bone mass, indicating that estrogen may not be the only mediator that induces osteoporosis. Recently, follicle-stimulating hormone (FSH), the serum concentration of which increases from the very beginning of menopause, has been found to play a key role in postmenopausal osteoporosis by promoting osteoclastogenesis. In this article, we confirmed that exogenous FSH can enhance osteoclast differentiation in vitro and that this effect can be neutralized by either an anti-FSH monoclonal antibody or anti-FSH polyclonal sera raised by immunizing animals with a recombinant GST-FSHβ fusion protein antigen. Moreover, immunizing ovariectomized rats with the GST-FSHβ antigen does significantly prevent trabecular bone loss and thereby enhance the bone strength, indicating that a FSH-based vaccine may be a promising therapeutic strategy to slow down bone loss in postmenopausal women.

  14. Identification of immediate early gene products of bovine herpes virus 1 (BHV-1) as dominant antigens recognized by CD8 T cells in immune cattle

    DEFF Research Database (Denmark)

    Hart, Jane; MacHugh, Niall D.; Sheldrake, Tara

    2017-01-01

    candidate viral gene products with CD8 T-cell lines from 3 BHV-1-immune cattle of defined MHC genotypes identified 4 antigens, including 3 immediate early (IE) gene products (ICP4, ICP22 and Circ) and a tegument protein (UL49). Identification of the MHC restriction specificities revealed that the antigens...... cases refined, the identity of the epitopes. Analyses of the epitope specificity of the CD8 T-cell lines showed that a large component of the response is directed against these IE epitopes. The results indicate that these IE gene products are dominant targets of the CD8 T-cell response in BHV...

  15. Cellular immune response from Chagasic patients to CRA or FRA recombinant antigens of Trypanosoma cruzi.

    Science.gov (United States)

    Lorena, Virginia M B; Verçosa, Alinne F A; Machado, Raquel C A; Moitinho-Silva, Lucas; Cavalcanti, Maria G A; Silva, Edimilson D; Ferreira, Antonio G P; Correa-Oliveira, Rodrigo; Pereira, Valéria R A; Gomes, Yara M

    2008-01-01

    We propose to analyze the relation between the cellular immune response of Chagas' disease patients after in vitro stimulation of peripheral blood mononuclear cells (PBMC) with recombinant antigens cytoplasmatic repetitive antigen (CRA) or flagellar repetitive antigen (FRA) of T. cruzi and the chronic clinical forms of disease. Cells were stimulated using phytohemagglutinin, CRA, FRA, or a soluble antigen of Epimastigota (Ag-Epi) for 24 hr, 72 hr, or 6 days. The proliferation of cells was evaluated after 6 days of culture by quantification of incorporated 3H-thymidine. Cytokines were measured in the supernatants obtained after 24 hr (tumor necrosis factor [TNF]-alpha and interleukin [IL]-4), 72 hr (IL-10), and 6 days (interferon [IFN]-gamma) using enzyme-linked immunosorbent assay (ELISA). Cells of the Chagas patients stimulated with the recombinant antigens exhibited higher proliferation responses compared with that of non-Chagas (NC) individuals. However, when proliferation was compared between patients with the cardiac form (CF) or indeterminate form (IF), it was not possible to establish a difference in the response. So far as the cytokines secreted in the culture supernatants after stimulation in vitro with T. cruzi antigens were concerned, the results showed that CRA, as well as Epi-Ag, were able to stimulate the production of TNF-alpha and IFN-gamma in Chagas patients as compared with NC individuals. However, the cytokine levels after stimulation with the T. cruzi antigens were not different between the patients with CF and IF. CRA was capable of inducing a T helper type 1 (Th1) immune response, with elevated production of TNF-alpha and IFN-gamma in Chagas patients that are carriers of CF and IF clinical forms. (Copyright ) 2008 Wiley-Liss, Inc.

  16. Leishmania-specific surface antigens show sub-genus sequence variation and immune recognition.

    Directory of Open Access Journals (Sweden)

    Daniel P Depledge

    2010-09-01

    Full Text Available A family of hydrophilic acylated surface (HASP proteins, containing extensive and variant amino acid repeats, is expressed at the plasma membrane in infective extracellular (metacyclic and intracellular (amastigote stages of Old World Leishmania species. While HASPs are antigenic in the host and can induce protective immune responses, the biological functions of these Leishmania-specific proteins remain unresolved. Previous genome analysis has suggested that parasites of the sub-genus Leishmania (Viannia have lost HASP genes from their genomes.We have used molecular and cellular methods to analyse HASP expression in New World Leishmania mexicana complex species and show that, unlike in L. major, these proteins are expressed predominantly following differentiation into amastigotes within macrophages. Further genome analysis has revealed that the L. (Viannia species, L. (V. braziliensis, does express HASP-like proteins of low amino acid similarity but with similar biochemical characteristics, from genes present on a region of chromosome 23 that is syntenic with the HASP/SHERP locus in Old World Leishmania species and the L. (L. mexicana complex. A related gene is also present in Leptomonas seymouri and this may represent the ancestral copy of these Leishmania-genus specific sequences. The L. braziliensis HASP-like proteins (named the orthologous (o HASPs are predominantly expressed on the plasma membrane in amastigotes and are recognised by immune sera taken from 4 out of 6 leishmaniasis patients tested in an endemic region of Brazil. Analysis of the repetitive domains of the oHASPs has shown considerable genetic variation in parasite isolates taken from the same patients, suggesting that antigenic change may play a role in immune recognition of this protein family.These findings confirm that antigenic hydrophilic acylated proteins are expressed from genes in the same chromosomal region in species across the genus Leishmania. These proteins are

  17. Characterization of a Mycobacterium leprae antigen related to the secreted Mycobacterium tuberculosis protein MPT32

    NARCIS (Netherlands)

    Wieles, B.; van Agterveld, M.; Janson, A.; Clark-Curtiss, J.; Rinke de Wit, T.; Harboe, M.; Thole, J.

    1994-01-01

    Secreted proteins may serve as major targets in the immune response to mycobacteria. To identify potentially secreted Mycobacterium leprae antigens, antisera specific for culture filtrate proteins of Mycobacterium tuberculosis were used to screen a panel of recombinant antigens selected previously

  18. 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.

  19. Hypoxia promotes tumor growth in linking angiogenesis to immune escape

    Directory of Open Access Journals (Sweden)

    Salem eCHOUAIB

    2012-02-01

    Full Text Available Despite the impressive progress over the past decade, in the field of tumor immunology, such as the identification of tumor antigens and antigenic peptides as potential targets, there are still many obstacles in eliciting an effective immune response to eradicate cancer. It has become increasingly clear that tumor microenvironment plays a crucial role in the control of immune protection and contains many overlapping mechanisms to evade antigen specific immunotherapy. Obviously, tumors have evolved to utilize hypoxic stress to their own advantage by activating key biochemical and cellular pathways that are important in progression, survival and metastasis. Among the hypoxia-induced genes, hypoxia-inducible factor (HIF-1 and vascular endothelial growth factor (VEGF play a determinant role in promoting tumor cell growth and survival. In this regard, hypoxia is emerging as an attractive target for cancer therapy. How the microenvironmental hypoxia poses both obstacles and opportunities for new therapeutic immune interventions will be discussed.

  20. Enhanced acquired antibodies to a chimeric Plasmodium falciparum antigen; UB05-09 is associated with protective immunity against malaria.

    Science.gov (United States)

    Dinga, J N; Gamua, S D; Titanji, V P K

    2017-08-01

    It has been shown that covalently linking two antigens could enhance the immunogenicity of the chimeric construct. To prioritize such a chimera for malaria vaccine development, it is necessary to demonstrate that naturally acquired antibodies against the chimera are associated with protection from malaria. Here, we probe the ability of a chimeric construct of UB05 and UB09 antigens (UB05-09) to better differentiate between acquired immune protection and susceptibility to malaria. In a cross-sectional study, recombinant UB05-09 chimera and the constituent antigens were used to probe for specific antibodies in the plasma from children and adults resident in a malaria-endemic zone, using the enzyme-linked immunosorbent assay (ELISA). Anti-UB05-09 antibody levels doubled that of its constituent antigens, UB09 and UB05, and this correlated with protection against malaria. The presence of enhanced UB05-09-specific antibody correlated with the absence of fever and parasitaemia, which are the main symptoms of malaria infection. The chimera is more effective in detecting and distinguishing acquired protective immunity against malaria than any of its constituents taken alone. Online B-cell epitope prediction tools confirmed the presence of B-cell epitopes in the study antigens. UB05-09 chimera is a marker of protective immunity against malaria that needs to be studied further. © 2017 John Wiley & Sons Ltd.

  1. The non-classical antigens of HLA-G and HLA-E as diagnostic and prognostic biomarkers and as therapeutic targets in transplantation and tumors.

    Science.gov (United States)

    Seliger, Barbara

    2013-01-01

    The non-classical human leukocyte antigen (HLA) class I antigen HLA-G represents a tolerogenic molecule and is involved in the inhibition of natural killer cell and cytotoxic T lymphocyte-mediated cytotoxicity. Under physiological conditions, HLA-G expression is mainly restricted to immune-privileged tissues, whereas it is overexpressed in tumors and transplants as well as in virus-infected cells. Due to its immunosuppressive features, HLA-G is important for pregnancy or organ transplantation and autoimmune diseases as well as cancer immune escape. This review focusses on the expression, regulation, and function of HLA-G in tumor cells andlor in transplants as well as therapeutic tools for enhancing (transplantation) or avoiding (tumor) tolerance. Thus, HLA-G or HLA-G-derived synthetic molecules might be used as therapeutic agents in combination with immunosuppressive drugs to enhance organ tolerance upon transplantation. In addition, HLA-G neoexpressing tumor cells could be targeted by HLA-G-specific microRNAs in order to enhance tumor immunogenicity.

  2. The specific targeting of immune regulation

    DEFF Research Database (Denmark)

    Andersen, Mads Hald

    2012-01-01

    as well as dendritic cells. Consequently, IDO may serve as a widely applicable target for immunotherapeutic strategies with a completely different function as well as expression pattern compared to previously described antigens. IDO constitutes a significant counter-regulatory mechanism induced by pro...

  3. The hemochromatosis protein HFE 20 years later: An emerging role in antigen presentation and in the immune system.

    Science.gov (United States)

    Reuben, Alexandre; Chung, Jacqueline W; Lapointe, Réjean; Santos, Manuela M

    2017-09-01

    Since its discovery, the hemochromatosis protein HFE has been primarily defined by its role in iron metabolism and homeostasis, and its involvement in the genetic disease termed hereditary hemochromatosis (HH). While HH patients are typically afflicted by dysregulated iron levels, many are also affected by several immune defects and increased incidence of autoimmune diseases that have thereby implicated HFE in the immune response. Growing evidence has supported an immunological role for HFE with recent studies describing HFE specifically as it relates to MHC I antigen presentation. Here, we present a comprehensive overview of the relationship between iron metabolism, HFE, and the immune system to better understand the origin and cause of immune defects in HH patients. We further describe the role of HFE in MHC I antigen presentation and its potential to impair autoimmune responses in homeostatic conditions, a mechanism which may be exploited by tumors to evade immune surveillance. Overall, this increased understanding of the role of HFE in the immune response sets the stage for better treatment and management of HH and other iron-related diseases, as well as of the immune defects related to this condition. © 2017 The Authors. Immunity, Inflammation and Disease Published by John Wiley & Sons Ltd.

  4. Antigen entrapped in the escheriosomes leads to the generation of CD4(+) helper and CD8(+) cytotoxic T cell response.

    Science.gov (United States)

    Syed, Faisal M; Khan, Masood A; Nasti, Tahseen H; Ahmad, Nadeem; Mohammad, Owais

    2003-06-02

    In previous study, we demonstrated the potential of Escherichia coli (E. coli) lipid liposomes (escheriosomes) to undergo membrane-membrane fusion with cytoplasmic membrane of the target cells including professional antigen presenting cells. Our present study demonstrates that antigen encapsulated in escheriosomes could be successfully delivered simultaneously to the cytosolic as well as endosomal processing pathways of antigen presenting cells, leading to the generation of both CD4(+) T-helper and CD8(+) cytotoxic T cell response. In contrast, encapsulation of same antigen in egg phosphatidyl-choline (egg PC) liposomes, just like antigen-incomplete Freund's adjuvant (IFA) complex, has inefficient access to the cytosolic pathway of MHC I-dependent antigen presentation and failed to generate antigen-specific CD8(+) cytotoxic T cell response. However, both egg PC liposomes as well as escheriosomes-encapsulated antigen elicited strong humoral immune response in immunized animals but antibody titre was significantly higher in the group of animals immunized with escheriosomes-encapsulated antigen. These results imply usage of liposome-based adjuvant as potential candidate vaccine capable of eliciting both cell-mediated as well as humoral immune responses. Furthermore, antigen entrapped in escheriosomes stimulates antigen-specific CD4(+) T cell proliferation and also enhances the level of IL-2, IFN-gamma and IL-4 in the immunized animals.

  5. 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

  6. Human IgG repertoire of malaria antigen-immunized human immune system (HIS) mice.

    Science.gov (United States)

    Nogueira, Raquel Tayar; Sahi, Vincent; Huang, Jing; Tsuji, Moriya

    2017-08-01

    Humanized mouse models present an important tool for preclinical evaluation of new vaccines and therapeutics. Here we show the human variable repertoire of antibody sequences cloned from a previously described human immune system (HIS) mouse model that possesses functional human CD4+ T cells and B cells, namely HIS-CD4/B mice. We sequenced variable IgG genes from single memory B-cell and plasma-cell sorted from splenocytes or whole blood lymphocytes of HIS-CD4/B mice that were vaccinated with a human plasmodial antigen, a recombinant Plasmodium falciparum circumsporozoite protein (rPfCSP). We demonstrate that rPfCSP immunization triggers a diverse B-cell IgG repertoire composed of various human VH family genes and distinct V(D)J recombinations that constitute diverse CDR3 sequences similar to humans, although low hypermutated sequences were generated. These results demonstrate the substantial genetic diversity of responding human B cells of HIS-CD4/B mice and their capacity to mount human IgG class-switched antibody response upon vaccination. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  7. Entirely Carbohydrate-Based Vaccines: An Emerging Field for Specific and Selective Immune Responses

    Directory of Open Access Journals (Sweden)

    Sharmeen Nishat

    2016-05-01

    Full Text Available Carbohydrates are regarded as promising targets for vaccine development against infectious disease because cell surface glycans on many infectious agents are attributed to playing an important role in pathogenesis. In addition, oncogenic transformation of normal cells, in many cases, is associated with aberrant glycosylation of the cell surface glycan generating tumor associated carbohydrate antigens (TACAs. Technological advances in glycobiology have added a new dimension to immunotherapy when considering carbohydrates as key targets in developing safe and effective vaccines to combat cancer, bacterial infections, viral infections, etc. Many consider effective vaccines induce T-cell dependent immunity with satisfactory levels of immunological memory that preclude recurrence. Unfortunately, carbohydrates alone are poorly immunogenic as they do not bind strongly to the MHCII complex and thus fail to elicit T-cell immunity. To increase immunogenicity, carbohydrates have been conjugated to carrier proteins, which sometimes can impede carbohydrate specific immunity as peptide-based immune responses can negate antibodies directed at the targeted carbohydrate antigens. To overcome many challenges in using carbohydrate-based vaccine design and development approaches targeting cancer and other diseases, zwitterionic polysaccharides (ZPSs, isolated from the capsule of commensal anaerobic bacteria, will be discussed as promising carriers of carbohydrate antigens to achieve desired immunological responses.

  8. Applying Mathematical Tools to Accelerate Vaccine Development: Modeling Shigella Immune Dynamics

    Science.gov (United States)

    Davis, Courtney L.; Wahid, Rezwanul; Toapanta, Franklin R.; Simon, Jakub K.

    2013-01-01

    We establish a mathematical framework for studying immune interactions with Shigella, a bacteria that kills over one million people worldwide every year. The long-term goal of this novel approach is to inform Shigella vaccine design by elucidating which immune components and bacterial targets are crucial for establishing Shigella immunity. Our delay differential equation model focuses on antibody and B cell responses directed against antigens like lipopolysaccharide in Shigella’s outer membrane. We find that antibody-based vaccines targeting only surface antigens cannot elicit sufficient immunity for protection. Additional boosting prior to infection would require a four-orders-of-magnitude increase in antibodies to sufficiently prevent epithelial invasion. However, boosting anti-LPS B memory can confer protection, which suggests these cells may correlate with immunity. We see that IgA antibodies are slightly more effective per molecule than IgG, but more total IgA is required due to spatial functionality. An extension of the model reveals that targeting both LPS and epithelial entry proteins is a promising avenue to advance vaccine development. This paper underscores the importance of multifaceted immune targeting in creating an effective Shigella vaccine. It introduces mathematical models to the Shigella vaccine development effort and lays a foundation for joint theoretical/experimental/clinical approaches to Shigella vaccine design. PMID:23589755

  9. Immunotoxic effect of thiamethoxam in immunized mice with Brucella abortus cultural filtrate antigen

    Directory of Open Access Journals (Sweden)

    L. H. Salema

    2016-12-01

    Full Text Available Aim: This study was planned for determination the toxic effect of thiamethoxam (TMX in immunized mice with Brucella abortus culture filtrate antigen (CFBAgs (as a vaccine and its role of TMX on decrease activity of B. abortus antigen on eliciting of humoral and cellular immunity. Materials and Methods: To achieve these goals 60 female mice were used, 7-8 weeks age, they were divided equally into three groups (20 in each group and treated as follows: 1st group: Mice were immunized with CFBAgs intraperitoneally in two doses, 2 weeks intervals with (protein concentration 2 mg\\ml, 2nd group: Mice immunized as in the 1st group and was administrated orally with 1/10 lethal dose 50% of TMX (83.7 mg/kg B.W. for 4 weeks daily, 3rd group was administrated orally with 0.3 ml normal saline served as a control group. At day 28 post immunization (PI delayed type hypersensitivity (skin test was done, and serum samples were collected at day 30 (PI for detection of passive hemagglutination test (PHA; interferon gamma (IFN-γ which was done by enzyme-linked immunosorbent assay test in addition to phagocytes assay. Results: The results of skin test post injection with soluble antigen of B. abortus intradermally showed a high significantly mean values at p≤0.05 of footpad skin thickness in the 1st group of mice which recorded (0.51±0.002 mm as compared with the 2nd group of mice which showed (0.08±0.002 mm after 24 h; the mean values of skin thickness were declined in the 1st mice (0.46±0.002 and 2nd mice (0.070±0.001 at 48 h; control group showed a negative results. These results were agreed with results of serum levels of IFN-γ (pg/ml that showed that a significant increase the vaccinated 1st group (406.36±1.52, than those values in the 2nd group (151.61±0.89 and negative result in 3rd group (46.47±0.60, in addition to results of PHA test which showed a significant increase in antibody titer in the 1st group (139±12.16 with low level of serum antibody

  10. Recombinant interleukin 6 with M cell-targeting moiety produced in Lactococcus lactis IL1403 as a potent mucosal adjuvant for peroral immunization.

    Science.gov (United States)

    Li, Hui-Shan; Piao, Da-Chuan; Jiang, Tao; Bok, Jin-Duck; Cho, Chong-Su; Lee, Yoon-Seok; Kang, Sang-Kee; Choi, Yun-Jaie

    2015-04-15

    Development and application of safe and effective mucosal adjuvants are important to improve immunization efficiency in oral vaccine. Here, we report a novel mucosal adjuvant, IL-6-CKS9, a recombinant cytokine generated by conjugating an M cell-targeting peptide (CKS9) with c-terminus of the murine interleukin 6 (IL-6), which facilitated enhancement of mucosal immune response. Lactococcus lactis IL1403, a food-grade strain of lactic acid bacteria (LAB) which is widely used in dairy industry, was used as a host cell to express and secrete the IL-6-CKS9 for a mucosal vaccine adjuvant. The recombinant L. lactis IL1403 secreting IL-6-CKS9 was orally administered with a model antigen protein, M-BmpB (Brachyspira membrane protein B conjugated with CKS9), to BALB/c mice for mucosal immunization. ELISA analyses showed consistent enhancement tendencies in induction of anti-M-BmpB antibody levels both with mucosal (IgA) and systemic (IgG) immune responses in IL-6-CKS9-LAB treated group compared with other groups tested by conducting two separated mice immunization assays. In addition, we characterized that the oral administration of model protein antigen with live LAB producing IL-6-CKS9 could induce both Th1 and Th2 type immune responses by analysis of the specific anti-BmpB IgG1 and IgG2a isotypes in the sera and also investigated possible oral tolerance in our vaccine strategy. Collectively, our results showed successful production and secretion of recombinant murine IL-6 with M cell-targeting moiety (IL-6-CKS9) from L. lactis IL1403 and demonstrated the live recombinant LAB producing IL-6-CKS9 could have a potential to be used as an efficient adjuvant for peroral vaccination. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Co-adjuvant effects of retinoic acid and IL-15 induce inflammatory immunity to dietary antigens

    Science.gov (United States)

    Under physiological conditions the gut-associated lymphoid tissues not only prevent the induction of a local inflammatory immune response, but also induce systemic tolerance to fed antigens. A notable exception is coeliac disease, where genetically susceptible individuals expressing human leukocyte...

  12. Autoantibodies in autoimmune thyroid disease promote immune complex formation with self antigens and increase B cell and CD4+ T cell proliferation in response to self antigens

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Hegedüs, Laszlo; Leslie, Robert Graham Quinton

    2004-01-01

    's thyroiditis (HT), Graves' disease (GD) and healthy controls were incubated with human thyroglobulin (Tg) before adding normal peripheral blood mononuclear cells. The deposition of immunoglobulins and C3 fragments on B cells was then assessed. Inclusion of Tg in serum from HT patients promoted B cell capture......B cells are centrally involved as antigen-presenting cells in certain autoimmune diseases. To establish whether autoantibodies form immune complexes (IC) with self-antigens in autoimmune thyroid disease (AITD) and promote B cell uptake of self-antigen, sera from patients with Hashimoto...

  13. Autoantibodies in autoimmune thyroid disease promote immune complex formation with self antigens and increase B cell and CD4+ T cell proliferation in response to self antigens

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Hegedüs, Laszlo; Leslie, Robert Graham Quinton

    2004-01-01

    B cells are centrally involved as antigen-presenting cells in certain autoimmune diseases. To establish whether autoantibodies form immune complexes (IC) with self-antigens in autoimmune thyroid disease (AITD) and promote B cell uptake of self-antigen, sera from patients with Hashimoto......'s thyroiditis (HT), Graves' disease (GD) and healthy controls were incubated with human thyroglobulin (Tg) before adding normal peripheral blood mononuclear cells. The deposition of immunoglobulins and C3 fragments on B cells was then assessed. Inclusion of Tg in serum from HT patients promoted B cell capture...

  14. Dendritic cells in dengue virus infection: Targets of virus replication and mediators of immunity

    Directory of Open Access Journals (Sweden)

    Michael A. Schmid

    2014-12-01

    Full Text Available Dendritic cells (DCs are sentinels of the immune system and detect pathogens at sites of entry, such as the skin. In addition to the ability of DCs to control infections directly via their innate immune functions, DCs help to prime adaptive B and T cell responses via antigen presentation in lymphoid tissues. Infected Aedes aegypti or Ae. albopictus mosquitoes transmit the four dengue virus (DENV serotypes to humans while probing for small blood vessels in the skin. DENV causes the most prevalent arthropod-borne viral disease in humans, yet no vaccine or specific therapeutic is currently approved. Although primary DENV infection confers life-long protective immunity against re-infection with the same DENV serotype, secondary infection with a different DENV serotype can lead to increased disease severity via cross-reactive T cells or enhancing antibodies. This review summarizes recent findings in humans and animal models about DENV infection of DCs, monocytes and macrophages. We discuss the dual role of DCs as both targets of DENV replication and mediators of innate and adaptive immunity, and summarize immune evasion strategies whereby DENV impairs the function of infected DCs. We suggest that DCs play a key role in priming DENV-specific neutralizing or potentially harmful memory B and T cell responses, and that future DC-directed therapies may help induce protective memory responses and reduce dengue pathogenesis.

  15. 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.

  16. 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

  17. Human Schistosoma haematobium antifecundity immunity is dependent on transmission intensity and associated with immunoglobulin G1 to worm-derived antigens

    DEFF Research Database (Denmark)

    Wilson, Shona; Jones, Frances M.; van Dam, Govert J.

    2014-01-01

    BACKGROUND: Immunity that reduces worm fecundity and, in turn, reduces morbidity is proposed for Schistosoma haematobium, a parasite of major public health importance. Mathematical models of epidemiological trends suggest that antifecundity immunity is dependent on antibody responses to adult......-worm-derived antigen. METHODS: For a Malian cohort (age, 5-29 years) residing in high-transmission fishing villages or a moderate-transmission village, worm fecundity was assessed using the ratio of urinary egg excretion to levels of circulating anodic antigen, a Schistosoma-specific antigen that is steadily secreted......, host age and transmission were negatively associated with worm fecundity. A significant interaction term between host age and transmission indicates that antifecundity immunity develops earlier in high-transmission areas. SWA immunoglobulin G1 (IgG1) levels explained the effect of transmission...

  18. Antigen Loss Variants: Catching Hold of Escaping Foes.

    Science.gov (United States)

    Vyas, Maulik; Müller, Rolf; Pogge von Strandmann, Elke

    2017-01-01

    Since mid-1990s, the field of cancer immunotherapy has seen steady growth and selected immunotherapies are now a routine and preferred therapeutic option of certain malignancies. Both active and passive cancer immunotherapies exploit the fact that tumor cells express specific antigens on the cell surface, thereby mounting an immune response specifically against malignant cells. It is well established that cancer cells typically lose surface antigens following natural or therapy-induced selective pressure and these antigen-loss variants are often the population that causes therapy-resistant relapse. CD19 and CD20 antigen loss in acute lymphocytic leukemia and chronic lymphocytic leukemia, respectively, and lineage switching in leukemia associated with mixed lineage leukemia (MLL) gene rearrangements are well-documented evidences in this regard. Although increasing number of novel immunotherapies are being developed, majority of these do not address the control of antigen loss variants. Here, we review the occurrence of antigen loss variants in leukemia and discuss the therapeutic strategies to tackle the same. We also present an approach of dual-targeting immunoligand effectively retargeting NK cells against antigen loss variants in MLL-associated leukemia. Novel immunotherapies simultaneously targeting more than one tumor antigen certainly hold promise to completely eradicate tumor and prevent therapy-resistant relapses.

  19. Rapid profiling of the antigen regions recognized by serum antibodies using massively parallel sequencing of antigen-specific libraries.

    KAUST Repository

    Domina, Maria; Lanza Cariccio, Veronica; Benfatto, Salvatore; D'Aliberti, Deborah; Venza, Mario; Borgogni, Erica; Castellino, Flora; Biondo, Carmelo; D'Andrea, Daniel; Grassi, Luigi; Tramontano, Anna; Teti, Giuseppe; Felici, Franco; Beninati, Concetta

    2014-01-01

    There is a need for techniques capable of identifying the antigenic epitopes targeted by polyclonal antibody responses during deliberate or natural immunization. Although successful, traditional phage library screening is laborious and can map only some of the epitopes. To accelerate and improve epitope identification, we have employed massive sequencing of phage-displayed antigen-specific libraries using the Illumina MiSeq platform. This enabled us to precisely identify the regions of a model antigen, the meningococcal NadA virulence factor, targeted by serum antibodies in vaccinated individuals and to rank hundreds of antigenic fragments according to their immunoreactivity. We found that next generation sequencing can significantly empower the analysis of antigen-specific libraries by allowing simultaneous processing of dozens of library/serum combinations in less than two days, including the time required for antibody-mediated library selection. Moreover, compared with traditional plaque picking, the new technology (named Phage-based Representation OF Immuno-Ligand Epitope Repertoire or PROFILER) provides superior resolution in epitope identification. PROFILER seems ideally suited to streamline and guide rational antigen design, adjuvant selection, and quality control of newly produced vaccines. Furthermore, this method is also susceptible to find important applications in other fields covered by traditional quantitative serology.

  20. Rapid profiling of the antigen regions recognized by serum antibodies using massively parallel sequencing of antigen-specific libraries.

    Directory of Open Access Journals (Sweden)

    Maria Domina

    Full Text Available There is a need for techniques capable of identifying the antigenic epitopes targeted by polyclonal antibody responses during deliberate or natural immunization. Although successful, traditional phage library screening is laborious and can map only some of the epitopes. To accelerate and improve epitope identification, we have employed massive sequencing of phage-displayed antigen-specific libraries using the Illumina MiSeq platform. This enabled us to precisely identify the regions of a model antigen, the meningococcal NadA virulence factor, targeted by serum antibodies in vaccinated individuals and to rank hundreds of antigenic fragments according to their immunoreactivity. We found that next generation sequencing can significantly empower the analysis of antigen-specific libraries by allowing simultaneous processing of dozens of library/serum combinations in less than two days, including the time required for antibody-mediated library selection. Moreover, compared with traditional plaque picking, the new technology (named Phage-based Representation OF Immuno-Ligand Epitope Repertoire or PROFILER provides superior resolution in epitope identification. PROFILER seems ideally suited to streamline and guide rational antigen design, adjuvant selection, and quality control of newly produced vaccines. Furthermore, this method is also susceptible to find important applications in other fields covered by traditional quantitative serology.

  1. Rapid profiling of the antigen regions recognized by serum antibodies using massively parallel sequencing of antigen-specific libraries.

    KAUST Repository

    Domina, Maria

    2014-12-04

    There is a need for techniques capable of identifying the antigenic epitopes targeted by polyclonal antibody responses during deliberate or natural immunization. Although successful, traditional phage library screening is laborious and can map only some of the epitopes. To accelerate and improve epitope identification, we have employed massive sequencing of phage-displayed antigen-specific libraries using the Illumina MiSeq platform. This enabled us to precisely identify the regions of a model antigen, the meningococcal NadA virulence factor, targeted by serum antibodies in vaccinated individuals and to rank hundreds of antigenic fragments according to their immunoreactivity. We found that next generation sequencing can significantly empower the analysis of antigen-specific libraries by allowing simultaneous processing of dozens of library/serum combinations in less than two days, including the time required for antibody-mediated library selection. Moreover, compared with traditional plaque picking, the new technology (named Phage-based Representation OF Immuno-Ligand Epitope Repertoire or PROFILER) provides superior resolution in epitope identification. PROFILER seems ideally suited to streamline and guide rational antigen design, adjuvant selection, and quality control of newly produced vaccines. Furthermore, this method is also susceptible to find important applications in other fields covered by traditional quantitative serology.

  2. Limited transplantation of antigen-expressing hematopoietic stem cells induces long-lasting cytotoxic T cell responses.

    Directory of Open Access Journals (Sweden)

    Warren L Denning

    2011-02-01

    Full Text Available Harnessing the ability of cytotoxic T lymphocytes (CTLs to recognize and eradicate tumor or pathogen-infected cells is a critical goal of modern immune-based therapies. Although multiple immunization strategies efficiently induce high levels of antigen-specific CTLs, the initial increase is typically followed by a rapid contraction phase resulting in a sharp decline in the frequency of functional CTLs. We describe a novel approach to immunotherapy based on a transplantation of low numbers of antigen-expressing hematopoietic stem cells (HSCs following nonmyeloablative or partially myeloablative conditioning. Continuous antigen presentation by a limited number of differentiated transgenic hematopoietic cells results in an induction and prolonged maintenance of fully functional effector T cell responses in a mouse model. Recipient animals display high levels of antigen-specific CTLs four months following transplantation in contrast to dendritic cell-immunized animals in which the response typically declines at 4-6 weeks post-immunization. Majority of HSC-induced antigen-specific CD8+ T cells display central memory phenotype, efficiently kill target cells in vivo, and protect recipients against tumor growth in a preventive setting. Furthermore, we confirm previously published observation that high level engraftment of antigen-expressing HSCs following myeloablative conditioning results in tolerance and an absence of specific cytotoxic activity in vivo. In conclusion, the data presented here supports potential application of immunization by limited transplantation of antigen-expressing HSCs for the prevention and treatment of cancer and therapeutic immunization of chronic infectious diseases such as HIV-1/AIDS.

  3. Viral subversion of the immune system

    International Nuclear Information System (INIS)

    Gillet, L.; Vanderplasschen, A.

    2005-01-01

    The continuous interactions between host and viruses during their co-evolution have shaped not only the immune system but also the countermeasures used by viruses. Studies in the last decade have described the diverse arrays of pathways and molecular targets that are used by viruses to elude immune detection or destruction, or both. These include targeting of pathways for major histocompatibility complex class I and class II antigen presentation, natural killer cell recognition, apoptosis, cytokine signalling, and complement activation. This paper provides an overview of the viral immune-evasion mechanisms described to date. It highlights the contribution of this field to our understanding of the immune system, and the importance of understanding this aspect of the biology of viral infection to develop efficacious and safe vaccines. (author)

  4. [Neoretinal antigen expression: a comparison of anatomical and clinical features of a murine uveoretinitis model].

    Science.gov (United States)

    Terrada, C; Pâques, M; Fisson, S; De Kozak, Y; Klatzmann, D; Salomon, B; LeHoang, P; Bodaghi, B

    2008-02-01

    Uveitis is an inflammation involving the retina. The antigens targeted by the experimental models are located in the pigmentary epithelium-photoreceptor complex. To gain insights into the variations in topographic expression of the antigen in the retina, we studied a new mouse model. and methods: Stable retinal expression of the influenza virus hemagglutinin (HA) was obtained after intravitreal or subretinal injection of recombinant adeno-associated virus carrying HA (AAV-HA). One month later, we transferred HA-specific T cells, followed by a subcutaneous immunization of the cognate antigen emulsified in CFA. The animals were clinically examined with a slit lamp biomicroscope. Infiltration of donor cells was detected by immunostaining on retina flatmounts with anti-Thy-1.1 antibody, and infiltrating cells were studied using FACS analysis. Whatever the location of the HA expression, intraocular inflammation was clinically and histologically detected in all animals, between 10 and 15 days after immunization with HA. Lesions were identified with histopathological analysis. The ocular infiltrate was mostly composed of macrophages and HA-specific T cells in different proportions. The topographic variations of targeted ocular antigens do not seem to modify the development of inflammatory reactions in our model. By targeting different antigen-presenting cells, ocular infiltrating cells are different.

  5. Targeting Mucosal Dendritic Cells with Microbial Antigens from Probiotic Lactic Acid Bacteria

    Science.gov (United States)

    2008-03-01

    this antigen-targeting approach to DCs, including B. anthracis protective antigen and botulinum toxin (heavy chain) in vivo. More studies are planned ...through impairment of germinal center development. Proc. Natl Acad. Sci. USA 91(7), 2639–2643 (1994). 45 Rescigno M, Urbano M, Valzasina B et al

  6. Detection of immune-complex-dissociated nonstructural-1 antigen in patients with acute dengue virus infections

    NARCIS (Netherlands)

    P. Koraka (Penelope); C.P. Burghoorn-Maas; A. Falconar; T.E. Setiati (Tatty); K. Djamiatun; J. Groen (Jan); A.D.M.E. Osterhaus (Albert)

    2003-01-01

    textabstractAccurate and timely diagnosis of dengue virus (DEN) infections is essential for the differential diagnosis of patients with febrile illness and hemorrhagic fever. In the present study, the diagnostic value of a newly developed immune-complex dissociated nonstructural-1 (NS-1) antigen dot

  7. Detection of immune-complex-dissociated nonstructural-1 antigen in patients with acute dengue virus infections.

    NARCIS (Netherlands)

    Koraka, P.; Burghoorn-Maas, C.P.; Falconar, A.; Setiati, T.E.; Djamiatun, K.; Groen, J.; Osterhaus, A.D.

    2003-01-01

    Accurate and timely diagnosis of dengue virus (DEN) infections is essential for the differential diagnosis of patients with febrile illness and hemorrhagic fever. In the present study, the diagnostic value of a newly developed immune-complex dissociated nonstructural-1 (NS-1) antigen dot blot

  8. Improved targeted immunization strategies based on two rounds of selection

    Science.gov (United States)

    Xia, Ling-Ling; Song, Yu-Rong; Li, Chan-Chan; Jiang, Guo-Ping

    2018-04-01

    In the case of high degree targeted immunization where the number of vaccine is limited, when more than one node associated with the same degree meets the requirement of high degree centrality, how can we choose a certain number of nodes from those nodes, so that the number of immunized nodes will not exceed the limit? In this paper, we introduce a new idea derived from the selection process of second-round exam to solve this problem and then propose three improved targeted immunization strategies. In these proposed strategies, the immunized nodes are selected through two rounds of selection, where we increase the quotas of first-round selection according the evaluation criterion of degree centrality and then consider another characteristic parameter of node, such as node's clustering coefficient, betweenness and closeness, to help choose targeted nodes in the second-round selection. To validate the effectiveness of the proposed strategies, we compare them with the degree immunizations including the high degree targeted and the high degree adaptive immunizations using two metrics: the size of the largest connected component of immunized network and the number of infected nodes. Simulation results demonstrate that the proposed strategies based on two rounds of sorting are effective for heterogeneous networks and their immunization effects are better than that of the degree immunizations.

  9. Identification and Characterization of Ixodes scapularis Antigens That Elicit Tick Immunity Using Yeast Surface Display

    NARCIS (Netherlands)

    Schuijt, T.J.; Narasimhan, S.; Daffre, S.; Deponte, K.; Hovius, J.W.R.; van 't Veer, C.; van der Poll, T.; Bakhtiari, K.; Meijers, J.C.M.; Boder, E.T.; van Dam, A.P.; Fikrig, E.

    2011-01-01

    Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary

  10. Specificity of antigens on UV radiation-induced antigenic tumor cell variants measured in vitro and in vivo

    International Nuclear Information System (INIS)

    Hostetler, L.W.; Romerdahl, C.A.; Kripke, M.L.

    1989-01-01

    The purpose of this study was to determine whether antigenic variants cross-react immunologically with the parental tumor and whether the UVR-associated antigen unique to UVR-induced tumors is also present on the variants. Antigenic (regressor) variants and nonimmunogenic (progressor) clones derived from UV-irradiated cultures of the C3H K1735 melanoma and SF19 spontaneous fibrosarcoma cell lines were used to address these questions. In an in vivo immunization and challenge assay, the antigenic variants did not induce cross-protection among themselves, but each induced immunity against the immunizing variant, the parent tumor cells, and nonimmunogenic clones derived from UV-irradiated parent cultures. Therefore, the variants can be used to induce in mice a protective immunity that prevents the growth of the parent tumor and nonimmunogenic clones, but not other antigenic variants. In contrast, immunization with cells of the parental tumor or the nonimmunogenic clones induced no protective immunity against challenge with any of the cell lines. Utilizing the K1735 melanoma-derived cell lines in vitro, T-helper (Th) cells isolated from tumor-immunized mice were tested for cross-reactivity by their ability to collaborate with trinitrophenyl-primed B-cells in the presence of trinitrophenyl-conjugated tumor cells. Also, the cross-reactivity of cytotoxic T-lymphocytes from tumor-immunized mice was assessed by a 4-h 51Cr-release assay. Antigenic variants induced cytotoxic T-lymphocytes and Th activity that was higher than that induced by the parent tumor and nonimmunogenic clones from the UVR-exposed parent tumor and cross-reacted with the parental tumor cells and nonimmunogenic clones, but not with other antigenic variants

  11. Immune response to Nocardia brasiliensis extracellular antigens in patients with mycetoma.

    Science.gov (United States)

    Castro-Matteotti, Bárbara; Vera-Cabrera, Lucio; Ocampo-Candiani, Jorge; Rendón, Adrián; Salinas-Carmona, Mario C; Welsh, Oliverio

    2008-03-01

    The ability of culture-filtrate proteins to induce a cellular immune response in infected mice and humans was investigated. A crude extract culture filtrate of Nocardia brasiliensis (CFA) and five semi-purified CFA fractions (P1, P2, P3, P4, P5) were used to stimulate BALB/c mice spleen-cell cultures. The animals were divided into three groups: the first group was infected with 1 x 10(7) CFU of N. brasiliensis in the footpad, the second group was immunized with heat-killed bacteria, and the third was injected with sterile saline. IFN-gamma, IL-1alpha, and IL-4 concentrations were determined in culture supernatants. Protein fractions eliciting IFN-gamma production in mice, as well as the CFA, were used to stimulate IFN-gamma production and in vitro cell proliferation assays with peripheral blood mononuclear cells of patients with actinomycetoma by N. brasiliensis, individuals with pulmonary tuberculosis, and healthy controls. In mice, CFA and three of the protein fractions (P3, P4 and P5) induced significant IFN-gamma production in the infected group. In humans, only the CFA-induced IFN-gamma production and cell proliferation in the group of patients with actinomycetoma. There was no stimulation in tuberculosis patients nor healthy controls. These results suggest that some culture-filtrate antigens are recognized by patients with active actinomycetoma and do not cross-react with M. tuberculosis antigens, being therefore potential candidates to develop a diagnostic test.

  12. Administration of sulfosuccinimidyl-4-[N-maleimidomethyl] cyclohexane-1-carboxylate conjugated GP10025–33 peptide-coupled spleen cells effectively mounts antigen-specific immune response against mouse melanoma

    International Nuclear Information System (INIS)

    Chang, Xiaoli; Xia, Chang-Qing

    2015-01-01

    It remains a top research priority to develop immunotherapeutic approaches to induce potent antigen-specific immune responses against tumors. However, in spite of some promising results, most strategies are ineffective because they generate low numbers of tumor-reactive cytotoxic T lymphocytes (CTLs). Here we designed a strategy to enhance antigen-specific immune response via administering sulfosuccinimidyl-4-[N-maleimidomethyl] cyclohexane-1-carboxylate (sulfo-SMCC)-conjugated melanoma tumor antigen GP100 25–33 peptide-coupled syngeneic spleen cells in a mouse model of melanoma. We found that infusion of GP100 25–33 peptide-coupled spleen cells significantly attenuated the growth of melanoma in prophylactic and therapeutic immunizations. Consistent with these findings, the adoptive transfer of spleen cells from immunized mice to naïve syngeneic mice was able to transfer anti-tumor effect, suggesting that GP100 25–33 peptide-specific immune response was induced. Further studies showed that, CD8+ T cell proliferation and the frequency of interferon (IFN)-γ-producing CD8+ T cells upon ex vivo stimulation by GP100 25–33 were significantly increased compared to control groups. Tumor antigen, GP100 25–23 specific immune response was also confirmed by ELISpot and GP100-tetramer assays. This approach is simple, easy-handled, and efficiently delivering antigens to lymphoid tissues. Our study offers an opportunity for clinically translating this approach into tumor immunotherapy. - Highlights: • Infusion of GP100 25–33 -coupled spleen cells leads to potent anti-melanoma immunity. • GP100 25–33 -coupled spleen cell treatment induces antigen-specific IFN-γ-producing CD8 T cells. • This approach takes advantage of homing nature of immune cells.

  13. Safety and skin delayed-type hypersensitivity response in vervet monkeys immunized with Leishmania donovani sonicate antigen delivered with adjuvants

    Directory of Open Access Journals (Sweden)

    Joshua M. Mutiso

    2012-02-01

    Full Text Available In this study, we report on the safety and skin delayed-type hypersensitivity (DTH, responses of the Leishmania donovani whole cell sonicate antigen delivered in conjunction with alum-BCG (AlBCG, Montanide ISA 720 (MISA or Monophosphoryl lipid A (MPLA in groups of vervet monkeys. Following three intradermal injections of the inoculums on days 0, 28 and 42, safety and DTH responses were assessed. Preliminary tumor necrosis factor alpha (TNF-α and interferon gamma (IFN-γ levels were also measured and these were compared with DTH. Only those animals immunized with alum-BCG reacted adversely to the inoculum by producing ulcerative erythematous skin indurations. Non-parametric analysis of variance followed by a post-test showed significantly higher DTH responses in the MISA+Ag group compared with other immunized groups (p < 0.001. The MPLA+Ag group indicated significantly lower DTH responses to the sonicate antigen compared with the AlBCG+Ag group. There was a significant correlation between the DTH and cytokine responses (p < 0.0001. Based on this study we conclude that Leishmania donovani sonicate antigen containing MISA 720 is safe and is associated with a strong DTH reaction following immunization.

  14. 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

  15. Screening Immunomodulators To Skew the Antigen-Specific Autoimmune Response.

    Science.gov (United States)

    Northrup, Laura; Sullivan, Bradley P; Hartwell, Brittany L; Garza, Aaron; Berkland, Cory

    2017-01-03

    Current therapies to treat autoimmune diseases often result in side effects such as nonspecific immunosuppression. Therapies that can induce antigen-specific immune tolerance provide an opportunity to reverse autoimmunity and mitigate the risks associated with global immunosuppression. In an effort to induce antigen-specific immune tolerance, co-administration of immunomodulators with autoantigens has been investigated in an effort to reprogram autoimmunity. To date, identifying immunomodulators that may skew the antigen-specific immune response has been ad hoc at best. To address this need, we utilized splenocytes obtained from mice with experimental autoimmune encephalomyelitis (EAE) in order to determine if certain immunomodulators may induce markers of immune tolerance following antigen rechallenge. Of the immunomodulatory compounds investigated, only dexamethasone modified the antigen-specific immune response by skewing the cytokine response and decreasing T-cell populations at a concentration corresponding to a relevant in vivo dose. Thus, antigen-educated EAE splenocytes provide an ex vivo screen for investigating compounds capable of skewing the antigen-specific immune response, and this approach could be extrapolated to antigen-educated cells from other diseases or human tissues.

  16. Circulating MicroRNAs in Plasma of Hepatitis B e Antigen Positive Children Reveal Liver-Specific Target Genes

    DEFF Research Database (Denmark)

    Winther, Thilde Nordmann; Jacobsen, Kari Stougaard; Mirza, Aashiq Hussain

    2014-01-01

    Background and Aim. Hepatitis B e antigen positive (HBeAg-positive) children are at high risk of severe complications such as hepatocellular carcinoma and cirrhosis. Liver damage is caused by the host immune response to infected hepatocytes, and we hypothesise that specific microRNAs play a role...... in this complex interaction between virus and host. The study aimed to identify microRNAs with aberrant plasma expressions in HBeAg-positive children and with liver-specific target genes. Methods. By revisiting our previous screen of microRNA plasma levels in HBeAg-positive and HBeAg-negative children...... with chronic hepatitis B (CHB) and in healthy controls, candidate microRNAs with aberrant plasma expressions in HBeAg-positive children were identified. MicroRNAs targeting liver-specific genes were selected based on bioinformatics analysis and validated by qRT-PCR using plasma samples from 34 HBe...

  17. Intranasal immunization with protective antigen of Bacillus anthracis induces a long-term immunological memory response.

    Science.gov (United States)

    Woo, Sun-Je; Kang, Seok-Seong; Park, Sung-Moo; Yang, Jae Seung; Song, Man Ki; Yun, Cheol-Heui; Han, Seung Hyun

    2015-10-01

    Although intranasal vaccination has been shown to be effective for the protection against inhalational anthrax, establishment of long-term immunity has yet to be achieved. Here, we investigated whether intranasal immunization with recombinant protective antigen (rPA) of Bacillus anthracis induces immunological memory responses in the mucosal and systemic compartments. Intranasal immunization with rPA plus cholera toxin (CT) sustained PA-specific antibody responses for 6 months in lung, nasal washes, and vaginal washes as well as serum. A significant induction of PA-specific memory B cells was observed in spleen, cervical lymph nodes (CLNs) and lung after booster immunization. Furthermore, intranasal immunization with rPA plus CT remarkably generated effector memory CD4(+) T cells in the lung. PA-specific CD4(+) T cells preferentially increased the expression of Th1- and Th17-type cytokines in lung, but not in spleen or CLNs. Collectively, the intranasal immunization with rPA plus CT promoted immunologic memory responses in the mucosal and systemic compartments, providing long-term immunity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Suppression of adaptive immunity to heterologous antigens during Plasmodium infection through hemozoin-induced failure of dendritic cell function

    Directory of Open Access Journals (Sweden)

    Phillips R

    2006-04-01

    Full Text Available Abstract Background Dendritic cells (DCs are central to the initiation and regulation of the adaptive immune response during infection. Modulation of DC function may therefore allow evasion of the immune system by pathogens. Significant depression of the host's systemic immune response to both concurrent infections and heterologous vaccines has been observed during malaria infection, but the mechanisms underlying this immune hyporesponsiveness are controversial. Results Here, we demonstrate that the blood stages of malaria infection induce a failure of DC function in vitro and in vivo, causing suboptimal activation of T cells involved in heterologous immune responses. This effect on T-cell activation can be transferred to uninfected recipients by DCs isolated from infected mice. Significantly, T cells activated by these DCs subsequently lack effector function, as demonstrated by a failure to migrate to lymphoid-organ follicles, resulting in an absence of B-cell responses to heterologous antigens. Fractionation studies show that hemozoin, rather than infected erythrocyte (red blood cell membranes, reproduces the effect of intact infected red blood cells on DCs. Furthermore, hemozoin-containing DCs could be identified in T-cell areas of the spleen in vivo. Conclusion Plasmodium infection inhibits the induction of adaptive immunity to heterologous antigens by modulating DC function, providing a potential explanation for epidemiological studies linking endemic malaria with secondary infections and reduced vaccine efficacy.

  19. Protective immune mechanisms against pre-erythrocytic forms of Plasmodium berghei depend on the target antigen

    Directory of Open Access Journals (Sweden)

    Elke S. Bergmann-Leitner

    2014-01-01

    Full Text Available Pre-erythrocytic malaria vaccines are believed to either stop the injected sporozoites from reaching the liver or to direct cellular immune responses towards eliminating infected hepatocytes. The present study reveals for the first time the anatomical sites at which these immune mechanisms act against the malaria parasites. To determine the mechanisms leading to protection mediated by two previously characterized vaccines against either the circumsporozoite protein (CSP or the cell traversal protein for ookinetes and sporozoites (CelTOS, mice were immunized and subsequently challenged by subcutaneous injection of salivary gland sporozoites of luciferase-transgenic Plasmodium berghei parasites. The In Vivo Imaging System (IVIS was used to identify the anatomical site where the vaccine-induced immune response eliminates sporozoites after injection. The data demonstrate that CSP-based immunity acts at the site of infection (skin whereas CelTOS-based immunity is only partially efficient in the skin and allows reduced levels of liver infection that can be subsequently cleared. The results of this study challenge assumptions regarding CSP-mediated immune mechanisms and call into question the validity of some commonly used assays to evaluate anti-CSP immune responses. The knowledge of the mechanism and events leading to infection or immune defense will guide supportive treatment with drugs or combination therapies and thus accelerate the development of effective antimalarial strategies.

  20. Progesterone impairs antigen-non-specific immune protection by CD8 T memory cells via interferon-γ gene hypermethylation.

    Science.gov (United States)

    Yao, Yushi; Li, Hui; Ding, Jie; Xia, Yixin; Wang, Lei

    2017-11-01

    Pregnant women and animals have increased susceptibility to a variety of intracellular pathogens including Listeria monocytogenes (LM), which has been associated with significantly increased level of sex hormones such as progesterone. CD8 T memory(Tm) cell-mediated antigen-non-specific IFN-γ responses are critically required in the host defense against LM. However, whether and how increased progesterone during pregnancy modulates CD8 Tm cell-mediated antigen-non-specific IFN-γ production and immune protection against LM remain poorly understood. Here we show in pregnant women that increased serum progesterone levels are associated with DNA hypermethylation of IFN-γ gene promoter region and decreased IFN-γ production in CD8 Tm cells upon antigen-non-specific stimulation ex vivo. Moreover, IFN-γ gene hypermethylation and significantly reduced IFN-γ production post LM infection in antigen-non-specific CD8 Tm cells are also observed in pregnant mice or progesterone treated non-pregnant female mice, which is a reversible phenotype following demethylation treatment. Importantly, antigen-non-specific CD8 Tm cells from progesterone treated mice have impaired anti-LM protection when adoptive transferred in either pregnant wild type mice or IFN-γ-deficient mice, and demethylation treatment rescues the adoptive protection of such CD8 Tm cells. These data demonstrate that increased progesterone impairs immune protective functions of antigen-non-specific CD8 Tm cells via inducing IFN-γ gene hypermethylation. Our findings thus provide insights into a new mechanism through which increased female sex hormone regulate CD8 Tm cell functions during pregnancy.

  1. Progesterone impairs antigen-non-specific immune protection by CD8 T memory cells via interferon-γ gene hypermethylation.

    Directory of Open Access Journals (Sweden)

    Yushi Yao

    2017-11-01

    Full Text Available Pregnant women and animals have increased susceptibility to a variety of intracellular pathogens including Listeria monocytogenes (LM, which has been associated with significantly increased level of sex hormones such as progesterone. CD8 T memory(Tm cell-mediated antigen-non-specific IFN-γ responses are critically required in the host defense against LM. However, whether and how increased progesterone during pregnancy modulates CD8 Tm cell-mediated antigen-non-specific IFN-γ production and immune protection against LM remain poorly understood. Here we show in pregnant women that increased serum progesterone levels are associated with DNA hypermethylation of IFN-γ gene promoter region and decreased IFN-γ production in CD8 Tm cells upon antigen-non-specific stimulation ex vivo. Moreover, IFN-γ gene hypermethylation and significantly reduced IFN-γ production post LM infection in antigen-non-specific CD8 Tm cells are also observed in pregnant mice or progesterone treated non-pregnant female mice, which is a reversible phenotype following demethylation treatment. Importantly, antigen-non-specific CD8 Tm cells from progesterone treated mice have impaired anti-LM protection when adoptive transferred in either pregnant wild type mice or IFN-γ-deficient mice, and demethylation treatment rescues the adoptive protection of such CD8 Tm cells. These data demonstrate that increased progesterone impairs immune protective functions of antigen-non-specific CD8 Tm cells via inducing IFN-γ gene hypermethylation. Our findings thus provide insights into a new mechanism through which increased female sex hormone regulate CD8 Tm cell functions during pregnancy.

  2. Immune response against antigens irradiated with 60Co gamma-rays

    International Nuclear Information System (INIS)

    Baptista, J.A.; Spencer, P.J.; Oliveira, J.E.; Casare, M.S.; Nascimento, N.

    2006-01-01

    In the present work, we investigated the immunological behavior of bothropstoxin-1, a K49 phospholipase from Bothrops jararacussu, and of ovalbumin before and after irradiation with 60 Co γ-rays. Isogenic mice were immunized with either native or irradiated proteins. The circulating antibodies were isotyped and titrated by ELISA. Results indicate that irradiated proteins were immunogenic and the antibodies elicited by them were able to recognize the native proteins in ELISA. Data also indicate that the irradiated protein induced higher titers of IgG2a and IgG2b, suggesting that Th1 cells were predominantly involved in the immune response. Structural modifications of the proteins were investigated by SDSPAGE, mass spectrometry and size exclusion chromatography. According to our data, irradiation promoted structural modifications on both proteins, characterized by higher molecular weight forms (aggregates and oligomers). When analyzed by mass spectrometry, the irradiated bothropstoxin appeared in several oxidized forms. These results indicate that irradiation of toxic proteins can promote significant modifications in their structures, but still retain many of the original antigenic and immunological properties of native form. (author)

  3. Partial Protection of Mice against Trypanosoma cruzi after Immunizing with the TcY 72 Antigenic Preparation

    Directory of Open Access Journals (Sweden)

    Yara M Gomes

    1999-03-01

    Full Text Available A 72 kDa Trypanosoma cruzi glycoprotein recognized by the 164C11 monoclonal antibody (IgM isotype was purified by preparative electrophoresis. The antigenic preparation obtained, named TcY 72, was used to immunize C57Bl/10 mice. The following results were observed after immunization: (1 induction of higher titres of IgG than IgM antibodies, as evaluated by indirect immunofluorescence; (2 significant DTH after injection of epimastigotes in mice footpads; (3 peak parasitemia in immunized mice was significantly reduced and animals were negative by 13 days post-infection, although the mice still succumb to infection; (4 the phenotypic analysis of spleen cell populations showed a decrease in the CD4/CD8 ratio in immunized mice. Taken as a whole, these findings indicate that TcY 72 is immunogenic and potentially important for protective immunity.

  4. Immunogenic Properties of Lactobacillus plantarum Producing Surface-Displayed Mycobacterium tuberculosis Antigens.

    Science.gov (United States)

    Kuczkowska, Katarzyna; Kleiveland, Charlotte R; Minic, Rajna; Moen, Lars F; Øverland, Lise; Tjåland, Rannei; Carlsen, Harald; Lea, Tor; Mathiesen, Geir; Eijsink, Vincent G H

    2017-01-15

    Tuberculosis (TB) remains among the most deadly diseases in the world. The only available vaccine against tuberculosis is the bacille Calmette-Guérin (BCG) vaccine, which does not ensure full protection in adults. There is a global urgency for the development of an effective vaccine for preventing disease transmission, and it requires novel approaches. We are exploring the use of lactic acid bacteria (LAB) as a vector for antigen delivery to mucosal sites. Here, we demonstrate the successful expression and surface display of a Mycobacterium tuberculosis fusion antigen (comprising Ag85B and ESAT-6, referred to as AgE6) on Lactobacillus plantarum The AgE6 fusion antigen was targeted to the bacterial surface using two different anchors, a lipoprotein anchor directing the protein to the cell membrane and a covalent cell wall anchor. AgE6-producing L. plantarum strains using each of the two anchors induced antigen-specific proliferative responses in lymphocytes purified from TB-positive donors. Similarly, both strains induced immune responses in mice after nasal or oral immunization. The impact of the anchoring strategies was reflected in dissimilarities in the immune responses generated by the two L. plantarum strains in vivo The present study comprises an initial step toward the development of L. plantarum as a vector for M. tuberculosis antigen delivery. This work presents the development of Lactobacillus plantarum as a candidate mucosal vaccine against tuberculosis. Tuberculosis remains one of the top infectious diseases worldwide, and the only available vaccine, bacille Calmette-Guérin (BCG), fails to protect adults and adolescents. Direct antigen delivery to mucosal sites is a promising strategy in tuberculosis vaccine development, and lactic acid bacteria potentially provide easy, safe, and low-cost delivery vehicles for mucosal immunization. We have engineered L. plantarum strains to produce a Mycobacterium tuberculosis fusion antigen and to anchor this

  5. Cell-mediated immunity against human retinal extract, S-antigen, and interphotoreceptor retinoid binding protein in onchocercal chorioretinopathy

    NARCIS (Netherlands)

    van der Lelij, A.; Rothova, A.; Stilma, J. S.; Hoekzema, R.; Kijlstra, A.

    1990-01-01

    Autoimmune mechanisms are thought to be involved in the pathogenesis of onchocercal chorioretinopathy. Cell-mediated immune responses to human retinal S-antigen, interphotoreceptor retinoid binding protein (IRBP), and crude retinal extract were investigated in patients with onchocerciasis from

  6. Trypanosoma cruzi vaccine candidate antigens Tc24 and TSA-1 recall memory immune response associated with HLA-A and -B supertypes in Chagasic chronic patients from Mexico.

    Science.gov (United States)

    Villanueva-Lizama, Liliana E; Cruz-Chan, Julio V; Aguilar-Cetina, Amarú Del C; Herrera-Sanchez, Luis F; Rodriguez-Perez, Jose M; Rosado-Vallado, Miguel E; Ramirez-Sierra, Maria J; Ortega-Lopez, Jaime; Jones, Kathryn; Hotez, Peter; Bottazzi, Maria Elena; Dumonteil, Eric

    2018-01-01

    Trypanosoma cruzi antigens TSA-1 and Tc24 have shown promise as vaccine candidates in animal studies. We evaluated here the recall immune response these antigens induce in Chagasic patients, as a first step to test their immunogenicity in humans. We evaluated the in vitro cellular immune response after stimulation with recombinant TSA-1 (rTSA-1) or recombinant Tc24 (rTc24) in mononuclear cells of asymptomatic Chagasic chronic patients (n = 20) compared to healthy volunteers (n = 19) from Yucatan, Mexico. Proliferation assays, intracellular cytokine staining, cytometric bead arrays, and memory T cell immunophenotyping were performed by flow cytometry. Peripheral blood mononuclear cells (PBMC) from Chagasic patients showed significant proliferation after stimulation with rTc24 and presented a phenotype of T effector memory cells (CD45RA-CCR7-). These cells also produced IFN-γ and, to a lesser extent IL10, after stimulation with rTSA-1 and rTc24 proteins. Overall, both antigens recalled a broad immune response in some Chagasic patients, confirming that their immune system had been primed against these antigens during natural infection. Analysis of HLA-A and HLA-B allele diversity by PCR-sequencing indicated that HLA-A03 and HLA-B07 were the most frequent supertypes in this Mexican population. Also, there was a significant difference in the frequency of HLA-A01 and HLA-A02 supertypes between Chagasic patients and controls, while the other alleles were evenly distributed. Some aspects of the immune response, such as antigen-induced IFN-γ production by CD4+ and CD8+ T cells and CD8+ proliferation, showed significant association with specific HLA-A supertypes, depending on the antigen considered. In conclusion, our results confirm the ability of both TSA-1 and Tc24 recombinant proteins to recall an immune response induced by the native antigens during natural infection in at least some patients. Our data support the further development of these antigens as therapeutic

  7. Antibody Responses to Prostate-Associated Antigens in Patients with Prostatitis and Prostate Cancer

    Science.gov (United States)

    Maricque, Brett B.; Eickhoff, Jens C.; McNeel, Douglas G.

    2010-01-01

    Background An important focus of tumor immunotherapy has been the identification of appropriate antigenic targets. Serum-based screening approaches have led to the discovery of hundreds of tumor-associated antigens recognized by IgG. Our efforts to identify immunologically recognized proteins in prostate cancer have yielded a multitude of antigens, however prioritizing these antigens as targets for evaluation in immunotherapies has been challenging. In this report, we set out to determine whether the evaluation of multiple antigenic targets would allow the identification of a subset of antigens that are common immunologic targets in patients with prostate cancer. Methods Using a phage immunoblot approach, we evaluated IgG responses in patients with prostate cancer (n=126), patients with chronic prostatitis (n=45), and men without prostate disease (n=53). Results We found that patients with prostate cancer or prostatitis have IgG specific for multiple common antigens. A subset of 23 proteins was identified to which IgG were detected in 38% of patients with prostate cancer and 33% patients with prostatitis versus 6% of controls (pprostate and prostate cancer, and suggest that IgG responses to a panel of commonly recognized prostate antigens could be potentially used in the identification of patients at risk for prostate cancer or as a tool to identify immune responses elicited to prostate tissue. PMID:20632317

  8. Large Scale Immune Profiling of Infected Humans and Goats Reveals Differential Recognition of Brucella melitensis Antigens

    Science.gov (United States)

    Liang, Li; Leng, Diana; Burk, Chad; Nakajima-Sasaki, Rie; Kayala, Matthew A.; Atluri, Vidya L.; Pablo, Jozelyn; Unal, Berkay; Ficht, Thomas A.; Gotuzzo, Eduardo; Saito, Mayuko; Morrow, W. John W.; Liang, Xiaowu; Baldi, Pierre; Gilman, Robert H.; Vinetz, Joseph M.; Tsolis, Renée M.; Felgner, Philip L.

    2010-01-01

    Brucellosis is a widespread zoonotic disease that is also a potential agent of bioterrorism. Current serological assays to diagnose human brucellosis in clinical settings are based on detection of agglutinating anti-LPS antibodies. To better understand the universe of antibody responses that develop after B. melitensis infection, a protein microarray was fabricated containing 1,406 predicted B. melitensis proteins. The array was probed with sera from experimentally infected goats and naturally infected humans from an endemic region in Peru. The assay identified 18 antigens differentially recognized by infected and non-infected goats, and 13 serodiagnostic antigens that differentiate human patients proven to have acute brucellosis from syndromically similar patients. There were 31 cross-reactive antigens in healthy goats and 20 cross-reactive antigens in healthy humans. Only two of the serodiagnostic antigens and eight of the cross-reactive antigens overlap between humans and goats. Based on these results, a nitrocellulose line blot containing the human serodiagnostic antigens was fabricated and applied in a simple assay that validated the accuracy of the protein microarray results in the diagnosis of humans. These data demonstrate that an experimentally infected natural reservoir host produces a fundamentally different immune response than a naturally infected accidental human host. PMID:20454614

  9. Protective immunity induced in mice by F8.1 and F8.2 antigens purified from Schistosoma mansoni eggs

    Directory of Open Access Journals (Sweden)

    Claudia Campra Ferreira

    1998-01-01

    Full Text Available Schistosoma mansoni soluble egg antigens (SEA were fractionated by isoelectric focusing, resulting in 20 components, characterized by pH, absorbance and protein concentration. The higher absorbance fractions were submitted to electrophoresis, and fraction 8 (F8 presented a specific pattern of bands on its isoelectric point. Protein 3 was observed only on F8, and so, it was utilized to rabbit immunization, in order to evaluate its capacity of inducing protective immunity. IgG antibodies from rabbit anti-F8 serum were coupled to Sepharose, and used to obtain the specific antigen by affinity chromatography. This antigen, submitted to electrophoresis, presented two proteic bands (F8.1 and F8.2, which were transferred to nitrocellulose membrane (PVDF and sequenciated. The homology of F8.2 to known proteins was determined using the Basic Local Alignment Search Tool program (BLASTp. Significant homologies were obtained for the rabbit cytosolic Ca2+ uptake inhibitor, and for the bird a1-proteinase inhibitor. Immunization of mice with F8.1 and F8.2, in the presence of Corynebacterium parvum and Al(OH3 as adjuvant, induced a significant protection degree against challenge infection, as observed by the decrease on worm burden recovered from portal system.

  10. Treatment of Schistosoma mansoni with miltefosine in vitro enhances serological recognition of defined worm surface antigens.

    Directory of Open Access Journals (Sweden)

    Marwa H El-Faham

    2017-08-01

    Full Text Available Miltefosine, an anti-cancer drug that has been successfully repositioned for treatment of Leishmania infections, has recently also shown promising effects against Schistosoma spp targeting all life cycle stages of the parasite. The current study examined the effect of treating Schistosoma mansoni adult worms with miltefosine on exposure of worm surface antigens in vitro.In an indirect immunofluorescence assay, rabbit anti-S.mansoni adult worm homogenate and anti-S. mansoni infection antisera gave strong immunofluorescence of the S. mansoni adult worm surface after treatment with miltefosine, the latter antiserum having previously been shown to synergistically enhance the schistosomicidal activity of praziquantel. Rabbit antibodies that recognised surface antigens exposed on miltefosine-treated worms were recovered by elution off the worm surface in low pH buffer and were used in a western immunoblotting assay to identify antigenic targets in a homogenate extract of adult worms (SmWH. Four proteins reacting with the antibodies in immunoblots were purified and proteomic analysis (MS/MS combined with specific immunoblotting indicated they were the S. mansoni proteins: fructose-1,6 bisphosphate aldolase (SmFBPA, Sm22.6, alkaline phosphatase and malate dehydrogenase. These antibodies were also found to bind to the surface of 3-hour schistosomula and induce immune agglutination of the parasites, suggesting they may have a role in immune protection.This study reveals a novel mode of action of miltefosine as an anti-schistosome agent. The immune-dependent hypothesis we investigated has previously been lent credence with praziquantel (PZQ, whereby treatment unmasks parasite surface antigens not normally exposed to the host during infection. Antigens involved in this molecular mechanism could have potential as intervention targets and antibodies against these antigens may act to increase the drug's anti-parasite efficacy and be involved in the development

  11. Immune chromatography: a quantitative radioimmunological assay

    International Nuclear Information System (INIS)

    Davis, J.W.; Demetriades, M.; Bowen, J.M.

    1984-01-01

    Immune chromatography, a radioimmunological binding assay, employs paper chromatography to separate immune complexes from free antigen and antibodies. During chromatography free antigen and antibodies become distributed throughout the paper, while immune complexes remain near the bottoms of the strips. The chromatographic differences can be made quantitative by using either iodinated antigens or antibodies. Under these conditions nanogram quantities of antigen can be detected or antibodies in sera diluted several 1000-fold. The immune chromatography assay can also be performed as an indirect assay, since the paper strips are cut from nitrocellulose paper. In this case the immune components are absorbed by the paper during chromatography. Antigen is then detected with an iodinated second antibody. The indirect immune chromatography assay is particularly useful for identifying different sera that react with the same antigen. Reaction with the first serum before chromatography reduces the amount of antigen available to the second serum following chromatography. In addition to characterizing the immune chromatography procedure, we discuss the possible applications of chromatography assays for the quantitation of other types of molecular binding interactions. (Auth.)

  12. Computational and Experimental Validation of B and T-Cell Epitopes of the In Vivo Immune Response to a Novel Malarial Antigen

    Science.gov (United States)

    2013-08-16

    KRATOS software package to determine which peptides were positive for binding with the immune antibodies. Immunizations Recombinant PfCelTOS with...Improved technique for the preparation of water-in-oil emulsions containing protein antigens. BioTechniques 20: 797–800. 34. Greenbaum JA, Andersen PH

  13. Naturally acquired immunity to Plasmodium falciparum malaria in Africa

    DEFF Research Database (Denmark)

    Hviid, Lars

    2005-01-01

    Infection by Plasmodium falciparum parasites can lead to substantial protective immunity to malaria, and available evidence suggest that acquisition of protection against some severe malaria syndromes can be fairly rapid. Although these facts have raised hopes that the development of effective...... protective immunity to P. falciparum malaria is acquired following natural exposure to the parasites is beginning to emerge, not least thanks to studies that have combined clinical and epidemiological data with basic immunological research. This framework involves IgG with specificity for clonally variant...... antigens on the surface of the infected erythrocytes, can explain some of the difficulties in relating particular immune responses with specificity for well-defined antigenic targets to clinical protection, and suggests a radically new approach to controlling malaria-related morbidity and mortality...

  14. Enhancing oral vaccine potency by targeting intestinal M cells.

    Directory of Open Access Journals (Sweden)

    Ali Azizi

    2010-11-01

    Full Text Available The immune system in the gastrointestinal tract plays a crucial role in the control of infection, as it constitutes the first line of defense against mucosal pathogens. The attractive features of oral immunization have led to the exploration of a variety of oral delivery systems. However, none of these oral delivery systems have been applied to existing commercial vaccines. To overcome this, a new generation of oral vaccine delivery systems that target antigens to gut-associated lymphoid tissue is required. One promising approach is to exploit the potential of microfold (M cells by mimicking the entry of pathogens into these cells. Targeting specific receptors on the apical surface of M cells might enhance the entry of antigens, initiating the immune response and consequently leading to protection against mucosal pathogens. In this article, we briefly review the challenges associated with current oral vaccine delivery systems and discuss strategies that might potentially target mouse and human intestinal M cells.

  15. Early secreted antigen ESAT-6 of Mycobacterium Tuberculosis promotes apoptosis of macrophages via targeting the microRNA155-SOCS1 interaction.

    Science.gov (United States)

    Yang, Shaojun; Li, Fake; Jia, Shuangrong; Zhang, Kejun; Jiang, Wenbing; Shang, Ya; Chang, Kai; Deng, Shaoli; Chen, Ming

    2015-01-01

    The early secreted antigenic target 6-kDa protein (ESAT-6) of Mycobacterium tuberculosis (Mtb) not only acts as a key player for virulence but also exhibits a strong immunotherapeutic potential against Mtb. However, little is known about the molecular basis for its potential in immunotherapy. The present study was designed to unravel the role of miRNA-155 in ESAT-6-mediated enhancement of host immunity and apoptosis in macrophages. Lentivirus-mediated miR-155 sponge and miR-155 and SOCS1 overexpression vectors were developed in macrophages. TLR2- or p65-specific siRNA knockdown was employed to silence TLR2 or p65. Quantitative polymerase chain reaction and western blotting analyses were performed to determine mRNA and protein expression levels, respectively. Macrophage apoptosis was analyzed by flow cytometry. ESAT-6 significantly increased miR-155 expression, which was dependent on TLR2/NF-κB activation in macrophages. Induced expression of miRNA-155 was required for the ESAT-6-mediated protective immune response and macrophage apoptosis. ESAT-6 promoted macrophage apoptosis by targeting the miR-155-SOCS1 pathway. The differential expression levels of TLR2, BIC, and SOCS1 were involved in regulating the immune response in human peripheral blood mononuclear cells of patients with active tuberculosis (TB) and latent TB (LTB). ESAT-6 promotes apoptosis of macrophages via targeting the miRNA155-SOCS1 interaction. © 2015 S. Karger AG, Basel.

  16. Early Secreted Antigen ESAT-6 of Mycobacterium Tuberculosis Promotes Apoptosis of Macrophages via Targeting the MicroRNA155-SOCS1 Interaction

    Directory of Open Access Journals (Sweden)

    Shaojun Yang

    2015-02-01

    Full Text Available Background: The early secreted antigenic target 6-kDa protein (ESAT-6 of Mycobacterium tuberculosis (Mtb not only acts as a key player for virulence but also exhibits a strong immunotherapeutic potential against Mtb. However, little is known about the molecular basis for its potential in immunotherapy. The present study was designed to unravel the role of miRNA-155 in ESAT-6-mediated enhancement of host immunity and apoptosis in macrophages. Methods: Lentivirus-mediated miR-155 sponge and miR-155 and SOCS1 overexpression vectors were developed in macrophages. TLR2- or p65-specific siRNA knockdown was employed to silence TLR2 or p65. Quantitative polymerase chain reaction and western blotting analyses were performed to determine mRNA and protein expression levels, respectively. Macrophage apoptosis was analyzed by flow cytometry. Results: ESAT-6 significantly increased miR-155 expression, which was dependent on TLR2/NF-κB activation in macrophages. Induced expression of miRNA-155 was required for the ESAT-6-mediated protective immune response and macrophage apoptosis. ESAT-6 promoted macrophage apoptosis by targeting the miR-155-SOCS1 pathway. The differential expression levels of TLR2, BIC, and SOCS1 were involved in regulating the immune response in human peripheral blood mononuclear cells of patients with active tuberculosis (TB and latent TB (LTB. Conclusion: ESAT-6 promotes apoptosis of macrophages via targeting the miRNA155-SOCS1 interaction.

  17. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA Induce Protective Immune Responses in Dogs.

    Directory of Open Access Journals (Sweden)

    Elodie Petitdidier

    2016-05-01

    Full Text Available Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA, from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA or its carboxy terminal part LaPSA-12S (Cter-rPSA, combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates.

  18. Rapid and Direct VHH and Target Identification by Staphylococcal Surface Display Libraries

    Directory of Open Access Journals (Sweden)

    Marco Cavallari

    2017-07-01

    Full Text Available Unbiased and simultaneous identification of a specific antibody and its target antigen has been difficult without prior knowledge of at least one interaction partner. Immunization with complex mixtures of antigens such as whole organisms and tissue extracts including tumoral ones evokes a highly diverse immune response. During such a response, antibodies are generated against a variety of epitopes in the mixture. Here, we propose a surface display design that is suited to simultaneously identify camelid single domain antibodies and their targets. Immune libraries of single-domain antigen recognition fragments from camelid heavy chain-only antibodies (VHH were attached to the peptidoglycan of Gram-positive Staphylococcus aureus employing its endogenous housekeeping sortase enzyme. The sortase transpeptidation reaction covalently attached the VHH to the bacterial peptidoglycan. The reversible nature of the reaction allowed the recovery of the VHH from the bacterial surface and the use of the VHH in downstream applications. These staphylococcal surface display libraries were used to rapidly identify VHH as well as their targets by immunoprecipitation (IP. Our novel bacterial surface display platform was stable under harsh screening conditions, allowed fast target identification, and readily permitted the recovery of the displayed VHH for downstream analysis.

  19. Antigen processing and remodeling of the endosomal pathway: requirements for antigen cross-presentation.

    Science.gov (United States)

    Compeer, Ewoud Bernardus; Flinsenberg, Thijs Willem Hendrik; van der Grein, Susanna Geertje; Boes, Marianne

    2012-01-01

    Cross-presentation of endocytosed antigen as peptide/class I major histocompatibility complex complexes plays a central role in the elicitation of CD8(+) T cell clones that mediate anti-viral and anti-tumor immune responses. While it has been clear that there are specific subsets of professional antigen presenting cells capable of antigen cross-presentation, identification of mechanisms involved is still ongoing. Especially amongst dendritic cells (DC), there are specialized subsets that are highly proficient at antigen cross-presentation. We here present a focused survey on the cell biological processes in the endosomal pathway that support antigen cross-presentation. This review highlights DC-intrinsic mechanisms that facilitate the cross-presentation of endocytosed antigen, including receptor-mediated uptake, maturation-induced endosomal sorting of membrane proteins, dynamic remodeling of endosomal structures and cell surface-directed endosomal trafficking. We will conclude with the description of pathogen-induced deviation of endosomal processing, and discuss how immune evasion strategies pertaining endosomal trafficking may preclude antigen cross-presentation.

  20. Antigen processing and remodeling of the endosomal pathway: requirements for antigen cross-presentation.

    Directory of Open Access Journals (Sweden)

    Ewoud Bernardus Compeer

    2012-03-01

    Full Text Available The cross-presentation of endocytosed antigen as peptide/class I MHC complexes plays a central role in the elicitation of CD8+ T cell clones that mediate anti-viral and anti-tumor immune responses. While it has been clear that there are specific subsets of professional antigen presenting cells (APC capable of antigen cross-presentation, description of mechanisms involved is still ongoing. Especially amongst dendritic cells (DC, there are specialized subsets that are highly proficient at antigen cross-presentation. We here present a focused survey on the cell biological processes in the endosomal pathway that support antigen cross-presentation. This review highlight DC-intrinsic mechanisms that facilitate the cross-presentation of endocytosed antigen, including receptor-mediated uptake, recycling and maturation including the sorting of membrane proteins, dynamic remodeling of endosomal structures and cell-surface directed endosomal trafficking. We will conclude with description of pathogen-induced deviation of endosomal processing, and discuss how immune evasion strategies pertaining endosomal trafficking may preclude antigen cross-presentation.

  1. Vaccination targeting human HER3 alters the phenotype of infiltrating T cells and responses to immune checkpoint inhibition.

    Science.gov (United States)

    Osada, Takuya; Morse, Michael A; Hobeika, Amy; Diniz, Marcio A; Gwin, William R; Hartman, Zachary; Wei, Junping; Guo, Hongtao; Yang, Xiao-Yi; Liu, Cong-Xiao; Kaneko, Kensuke; Broadwater, Gloria; Lyerly, H Kim

    2017-01-01

    Expression of human epidermal growth factor family member 3 (HER3), a critical heterodimerization partner with EGFR and HER2, promotes more aggressive biology in breast and other epithelial malignancies. As such, inhibiting HER3 could have broad applicability to the treatment of EGFR- and HER2-driven tumors. Although lack of a functional kinase domain limits the use of receptor tyrosine kinase inhibitors, HER3 contains antigenic targets for T cells and antibodies. Using novel human HER3 transgenic mouse models of breast cancer, we demonstrate that immunization with recombinant adenoviral vectors encoding full length human HER3 (Ad-HER3-FL) induces HER3-specific T cells and antibodies, alters the T cell infiltrate in tumors, and influences responses to immune checkpoint inhibitions. Both preventative and therapeutic Ad-HER3-FL immunization delayed tumor growth but were associated with both intratumoral PD-1 expressing CD8 + T cells and regulatory CD4 + T cell infiltrates. Immune checkpoint inhibition with either anti-PD-1 or anti-PD-L1 antibodies increased intratumoral CD8 + T cell infiltration and eliminated tumor following preventive vaccination with Ad-HER3-FL vaccine. The combination of dual PD-1/PD-L1 and CTLA4 blockade slowed the growth of tumor in response to Ad-HER3-FL in the therapeutic model. We conclude that HER3-targeting vaccines activate HER3-specific T cells and induce anti-HER3 specific antibodies, which alters the intratumoral T cell infiltrate and responses to immune checkpoint inhibition.

  2. Inverse targeting —An effective immunization strategy

    Science.gov (United States)

    Schneider, C. M.; Mihaljev, T.; Herrmann, H. J.

    2012-05-01

    We propose a new method to immunize populations or computer networks against epidemics which is more efficient than any continuous immunization method considered before. The novelty of our method resides in the way of determining the immunization targets. First we identify those individuals or computers that contribute the least to the disease spreading measured through their contribution to the size of the largest connected cluster in the social or a computer network. The immunization process follows the list of identified individuals or computers in inverse order, immunizing first those which are most relevant for the epidemic spreading. We have applied our immunization strategy to several model networks and two real networks, the Internet and the collaboration network of high-energy physicists. We find that our new immunization strategy is in the case of model networks up to 14%, and for real networks up to 33% more efficient than immunizing dynamically the most connected nodes in a network. Our strategy is also numerically efficient and can therefore be applied to large systems.

  3. Recombinant Lactobacillus plantarum induces immune responses to cancer testis antigen NY-ESO-1 and maturation of dendritic cells

    Science.gov (United States)

    Mobergslien, Anne; Vasovic, Vlada; Mathiesen, Geir; Fredriksen, Lasse; Westby, Phuong; Eijsink, Vincent GH; Peng, Qian; Sioud, Mouldy

    2015-01-01

    Given their safe use in humans and inherent adjuvanticity, Lactic Acid Bacteria may offer several advantages over other mucosal delivery strategies for cancer vaccines. The objective of this study is to evaluate the immune responses in mice after oral immunization with Lactobacillus (L) plantarum WCFS1 expressing a cell-wall anchored tumor antigen NY-ESO-1. And to investigate the immunostimulatory potency of this new candidate vaccine on human dendritic cells (DCs). L. plantarum displaying NY-ESO-1 induced NY-ESO-1 specific antibodies and T-cell responses in mice. By contrast, L. plantarum displaying conserved proteins such as heat shock protein-27 and galectin-1, did not induce immunity, suggesting that immune tolerance to self-proteins cannot be broken by oral administration of L. plantarum. With respect to immunomodulation, immature DCs incubated with wild type or L. plantarum-NY-ESO-1 upregulated the expression of co-stimulatory molecules and secreted a large amount of interleukin (IL)-12, TNF-α, but not IL-4. Moreover, they upregulated the expression of immunosuppressive factors such as IL-10 and indoleamine 2,3-dioxygenase. Although L. plantarum-matured DCs expressed inhibitory molecules, they stimulated allogeneic T cells in-vitro. Collectively, the data indicate that L. plantarum-NY-ESO-1 can evoke antigen-specific immunity upon oral administration and induce DC maturation, raising the potential of its use in cancer immunotherapies. PMID:26185907

  4. Carbamylated albumin is one of the target antigens of anti-carbamylated protein antibodies.

    Science.gov (United States)

    Nakabo, Shuichiro; Hashimoto, Motomu; Ito, Shinji; Furu, Moritoshi; Ito, Hiromu; Fujii, Takao; Yoshifuji, Hajime; Imura, Yoshitaka; Nakashima, Ran; Murakami, Kosaku; Kuramoto, Nobuo; Tanaka, Masao; Satoh, Junko; Ishigami, Akihito; Morita, Satoshi; Mimori, Tsuneyo; Ohmura, Koichiro

    2017-07-01

    Anti-carbamylated protein (anti-CarP) antibodies are detected in RA patients. Fetal calf serum is used as an antigen source in anti-CarP ELISA, and the precise target antigens have not been found. We aimed to identify the target antigens of anti-CarP antibodies. Western blotting of anti-CarP antibodies was conducted. Anti-carbamylated human albumin (CarALB) antibody was detected by in-house ELISA for 493 RA patients and 144 healthy controls (HCs). An inhibition ELISA of anti-CarP antibodies by CarALB and citrullinated albumin (citALB) was performed using eight RA patients' sera. Serum CarALB was detected by liquid chromatography-tandem mass spectroscopy (LC/MS/MS), and the serum MPO concentration was measured by ELISA. We focused on carbamylated albumin because it corresponded to the size of the thickest band detected by western blotting of anti-CarP antibodies. Anti-CarALB antibody was detected in 31.4% of RA patients, and the correlation of the titres between anti-CarALB and anti-CarP was much closer than that between anti-citALB and anti-CCP antibodies (ρ = 0.59 and ρ = 0.16, respectively). The inhibition ELISA showed that anti-CarP antibodies were inhibited by CarALB, but not by citALB. CarALB was detected in sera from RA patients by LC/MS/MS. The serum MPO concentration was correlated with disease activity and was higher in RA patients with anti-CarALB antibody than in those without. We found that carbamylated albumin is a novel target antigen of anti-CarP antibodies, and it is the first reported target antigen that has not been reported as the target of ACPA. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  5. PSMA-targeted polyinosine/polycytosine vector induces prostate tumor regression and invokes an antitumor immune response in mice.

    Science.gov (United States)

    Langut, Yael; Talhami, Alaa; Mamidi, Samarasimhareddy; Shir, Alexei; Zigler, Maya; Joubran, Salim; Sagalov, Anna; Flashner-Abramson, Efrat; Edinger, Nufar; Klein, Shoshana; Levitzki, Alexander

    2017-12-26

    There is an urgent need for an effective treatment for metastatic prostate cancer (PC). Prostate tumors invariably overexpress prostate surface membrane antigen (PSMA). We designed a nonviral vector, PEI-PEG-DUPA (PPD), comprising polyethylenimine-polyethyleneglycol (PEI-PEG) tethered to the PSMA ligand, 2-[3-(1, 3-dicarboxy propyl)ureido] pentanedioic acid (DUPA), to treat PC. The purpose of PEI is to bind polyinosinic/polycytosinic acid (polyIC) and allow endosomal release, while DUPA targets PC cells. PolyIC activates multiple pathways that lead to tumor cell death and to the activation of bystander effects that harness the immune system against the tumor, attacking nontargeted neighboring tumor cells and reducing the probability of acquired resistance and disease recurrence. Targeting polyIC directly to tumor cells avoids the toxicity associated with systemic delivery. PPD selectively delivered polyIC into PSMA-overexpressing PC cells, inducing apoptosis, cytokine secretion, and the recruitment of human peripheral blood mononuclear cells (PBMCs). PSMA-overexpressing tumors in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice with partially reconstituted immune systems were significantly shrunken following PPD/polyIC treatment, in all cases. Half of the tumors showed complete regression. PPD/polyIC invokes antitumor immunity, but unlike many immunotherapies does not need to be personalized for each patient. The potent antitumor effects of PPD/polyIC should spur its development for clinical use.

  6. Administration of sulfosuccinimidyl-4-[N-maleimidomethyl] cyclohexane-1-carboxylate conjugated GP100{sub 25–33} peptide-coupled spleen cells effectively mounts antigen-specific immune response against mouse melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Xiaoli [Department of Hematology, Xuanwu Hospital, Capital Medical University, Beijing (China); Xia, Chang-Qing, E-mail: cqx65@yahoo.com [Department of Hematology, Xuanwu Hospital, Capital Medical University, Beijing (China); Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL32610 (United States)

    2015-12-04

    It remains a top research priority to develop immunotherapeutic approaches to induce potent antigen-specific immune responses against tumors. However, in spite of some promising results, most strategies are ineffective because they generate low numbers of tumor-reactive cytotoxic T lymphocytes (CTLs). Here we designed a strategy to enhance antigen-specific immune response via administering sulfosuccinimidyl-4-[N-maleimidomethyl] cyclohexane-1-carboxylate (sulfo-SMCC)-conjugated melanoma tumor antigen GP100{sub 25–33} peptide-coupled syngeneic spleen cells in a mouse model of melanoma. We found that infusion of GP100{sub 25–33} peptide-coupled spleen cells significantly attenuated the growth of melanoma in prophylactic and therapeutic immunizations. Consistent with these findings, the adoptive transfer of spleen cells from immunized mice to naïve syngeneic mice was able to transfer anti-tumor effect, suggesting that GP100{sub 25–33} peptide-specific immune response was induced. Further studies showed that, CD8+ T cell proliferation and the frequency of interferon (IFN)-γ-producing CD8+ T cells upon ex vivo stimulation by GP100{sub 25–33} were significantly increased compared to control groups. Tumor antigen, GP100{sub 25–23} specific immune response was also confirmed by ELISpot and GP100-tetramer assays. This approach is simple, easy-handled, and efficiently delivering antigens to lymphoid tissues. Our study offers an opportunity for clinically translating this approach into tumor immunotherapy. - Highlights: • Infusion of GP100{sub 25–33}-coupled spleen cells leads to potent anti-melanoma immunity. • GP100{sub 25–33}-coupled spleen cell treatment induces antigen-specific IFN-γ-producing CD8 T cells. • This approach takes advantage of homing nature of immune cells.

  7. Original antigenic sin: A comprehensive review.

    Science.gov (United States)

    Vatti, Anup; Monsalve, Diana M; Pacheco, Yovana; Chang, Christopher; Anaya, Juan-Manuel; Gershwin, M Eric

    2017-09-01

    The concept of "original antigenic sin" was first proposed by Thomas Francis, Jr. in 1960. This phenomenon has the potential to rewrite what we understand about how the immune system responds to infections and its mechanistic implications on how vaccines should be designed. Antigenic sin has been demonstrated to occur in several infectious diseases in both animals and humans, including human influenza infection and dengue fever. The basis of "original antigenic sin" requires immunological memory, and our immune system ability to autocorrect. In the context of viral infections, it is expected that if we are exposed to a native strain of a pathogen, we should be able to mount a secondary immune response on subsequent exposure to the same pathogen. "Original antigenic sin" will not contradict this well-established immunological process, as long as the subsequent infectious antigen is identical to the original one. But "original antigenic sin" implies that when the epitope varies slightly, then the immune system relies on memory of the earlier infection, rather than mount another primary or secondary response to the new epitope which would allow faster and stronger responses. The result is that the immunological response may be inadequate against the new strain, because the immune system does not adapt and instead relies on its memory to mount a response. In the case of vaccines, if we only immunize to a single strain or epitope, and if that strain/epitope changes over time, then the immune system is unable to mount an accurate secondary response. In addition, depending of the first viral exposure the secondary immune response can result in an antibody-dependent enhancement of the disease or at the opposite, it could induce anergy. Both of them triggering loss of pathogen control and inducing aberrant clinical consequences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Proliferation induced by Plasmodium falciparum antigen and interleukin-2 production by lymphocytes isolated from malaria-immune individuals

    DEFF Research Database (Denmark)

    Theander, T G; Bygbjerg, I C; Jepsen, S

    1986-01-01

    Affinity-purified Plasmodium falciparum soluble antigens (SPAg) isolated from in vitro cultures of the parasite were shown to be relatively free of nonspecific polyclonal activators. To determine the presence of lymphocytes with specificity against SPAg in the peripheral blood of malaria-immune i......Affinity-purified Plasmodium falciparum soluble antigens (SPAg) isolated from in vitro cultures of the parasite were shown to be relatively free of nonspecific polyclonal activators. To determine the presence of lymphocytes with specificity against SPAg in the peripheral blood of malaria...

  9. 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.

  10. The Antigen Presenting Cells Instruct Plasma Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Wei eXu

    2014-01-01

    Full Text Available The professional antigen presenting cells (APCs, including many subsets of dendritic cells and macrophages, not only mediate prompt but nonspecific response against microbes, but also bridge the antigen-specific adaptive immune response through antigen presentation. In the latter, typically activated B cells acquire cognate signals from T helper cells in the germinal center of lymphoid follicles to differentiate into plasma cells, which generate protective antibodies. Recent advances have revealed that many APC subsets provide not only signal 1 (the antigen, but also signal 2 to directly instruct the differentiation process of plasma cells in a T cell-independent manner. Herein, the different signals provided by these APC subsets to direct B cell proliferation, survival, class switching and terminal differentiation are discussed. We furthermore propose that the next generation of vaccines for boosting antibody response could be designed by targeting APCs.

  11. The antigen presenting cells instruct plasma cell differentiation.

    Science.gov (United States)

    Xu, Wei; Banchereau, Jacques

    2014-01-06

    The professional antigen presenting cells (APCs), including many subsets of dendritic cells and macrophages, not only mediate prompt but non-specific response against microbes, but also bridge the antigen-specific adaptive immune response through antigen presentation. In the latter, typically activated B cells acquire cognate signals from T helper cells in the germinal center of lymphoid follicles to differentiate into plasma cells (PCs), which generate protective antibodies. Recent advances have revealed that many APC subsets provide not only "signal 1" (the antigen), but also "signal 2" to directly instruct the differentiation process of PCs in a T-cell-independent manner. Herein, the different signals provided by these APC subsets to direct B cell proliferation, survival, class switching, and terminal differentiation are discussed. We furthermore propose that the next generation of vaccines for boosting antibody response could be designed by targeting APCs.

  12. TNF-Induced Target Cell Killing by CTL Activated through Cross-Presentation

    Directory of Open Access Journals (Sweden)

    Dirk Wohlleber

    2012-09-01

    Full Text Available Viruses can escape cytotoxic T cell (CTL immunity by avoiding presentation of viral components via endogenous MHC class I antigen presentation in infected cells. Cross-priming of viral antigens circumvents such immune escape by allowing noninfected dendritic cells to activate virus-specific CTLs, but they remain ineffective against infected cells in which immune escape is functional. Here, we show that cross-presentation of antigen released from adenovirus-infected hepatocytes by liver sinusoidal endothelial cells stimulated cross-primed effector CTLs to release tumor necrosis factor (TNF, which killed virus-infected hepatocytes through caspase activation. TNF receptor signaling specifically eliminated infected hepatocytes that showed impaired anti-apoptotic defense. Thus, CTL immune surveillance against infection relies on two similarly important but distinct effector functions that are both MHC restricted, requiring either direct antigen recognition on target cells and canonical CTL effector function or cross-presentation and a noncanonical effector function mediated by TNF.

  13. TNF-induced target cell killing by CTL activated through cross-presentation.

    Science.gov (United States)

    Wohlleber, Dirk; Kashkar, Hamid; Gärtner, Katja; Frings, Marianne K; Odenthal, Margarete; Hegenbarth, Silke; Börner, Carolin; Arnold, Bernd; Hämmerling, Günter; Nieswandt, Bernd; van Rooijen, Nico; Limmer, Andreas; Cederbrant, Karin; Heikenwalder, Mathias; Pasparakis, Manolis; Protzer, Ulrike; Dienes, Hans-Peter; Kurts, Christian; Krönke, Martin; Knolle, Percy A

    2012-09-27

    Viruses can escape cytotoxic T cell (CTL) immunity by avoiding presentation of viral components via endogenous MHC class I antigen presentation in infected cells. Cross-priming of viral antigens circumvents such immune escape by allowing noninfected dendritic cells to activate virus-specific CTLs, but they remain ineffective against infected cells in which immune escape is functional. Here, we show that cross-presentation of antigen released from adenovirus-infected hepatocytes by liver sinusoidal endothelial cells stimulated cross-primed effector CTLs to release tumor necrosis factor (TNF), which killed virus-infected hepatocytes through caspase activation. TNF receptor signaling specifically eliminated infected hepatocytes that showed impaired anti-apoptotic defense. Thus, CTL immune surveillance against infection relies on two similarly important but distinct effector functions that are both MHC restricted, requiring either direct antigen recognition on target cells and canonical CTL effector function or cross-presentation and a noncanonical effector function mediated by TNF. Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Immune Repertoire after Immunization As Seen by Next-Generation Sequencing and Proteomics

    Directory of Open Access Journals (Sweden)

    Martijn M. VanDuijn

    2017-10-01

    Full Text Available The immune system produces a diverse repertoire of immunoglobulins in response to foreign antigens. During B-cell development, VDJ recombination and somatic mutations generate diversity, whereas selection processes remove it. Using both proteomic and NGS approaches, we characterized the immune repertoires in groups of rats after immunization with purified antigens. Proteomics and NGS data on the repertoire are in qualitative agreement, but did show quantitative differences that may relate to differences between the biological niches that were sampled for these approaches. Both methods contributed complementary information in the characterization of the immune repertoire. It was found that the immune repertoires resulting from each antigen had many similarities that allowed samples to cluster together, and that mutated immunoglobulin peptides were shared among animals with a response to the same antigen significantly more than for different antigens. However, the number of shared sequences decreased in a log-linear fashion relative to the number of animals that share them, which may affect future applications. A phylogenetic analysis on the NGS reads showed that reads from different individuals immunized with the same antigen populated distinct branches of the phylogram, an indication that the repertoire had converged. Also, similar mutation patterns were found in branches of the phylogenetic tree that were associated with antigen-specific immunoglobulins through proteomics data. Thus, data from different analysis methods and different experimental platforms show that the immunoglobulin repertoires of immunized animals have overlapping and converging features. With additional research, this may enable interesting applications in biotechnology and clinical diagnostics.

  15. Environmental proxies of antigen exposure explain variation in immune investment better than indices of pace of life

    NARCIS (Netherlands)

    Horrocks, Nicholas P. C.; Hegemann, Arne; Ostrowski, Stephane; Ndithia, Henry; Shobrak, Mohammed; Williams, Joseph B.; Matson, Kevin D.; Tieleman, B. I.

    Investment in immune defences is predicted to covary with a variety of ecologically and evolutionarily relevant axes, with pace of life and environmental antigen exposure being two examples. These axes may themselves covary directly or inversely, and such relationships can lead to conflicting

  16. Environmental proxies of antigen exposure explain variation in immune investment better than indices of pace of life

    NARCIS (Netherlands)

    Horrocks, N.P.C.; Hegemann, A.; Ostrowski, S.; Ndithia, H.; Shobrak, M.; Williams, J.B.; Matson, K.D.; Tieleman, B.I.

    2015-01-01

    Investment in immune defences is predicted to covary with a variety of ecologically and evolutionarily relevant axes, with pace of life and environmental antigen exposure being two examples. These axes may themselves covary directly or inversely, and such relationships can lead to conflicting

  17. The role of MPL and imiquimod adjuvants in enhancement of immune response and protection in BALB/c mice immunized with soluble Leishmania antigen (SLA) encapsulated in nanoliposome.

    Science.gov (United States)

    Emami, Tara; Rezayat, Seyed Mahdi; Khamesipour, Ali; Madani, Rasool; Habibi, Gholamreza; Hojatizade, Mansure; Jaafari, Mahmoud Reza

    2018-04-01

    Adjuvants play an essential role in the induction of immunity against leishmaniasis. In this study, monophosphoryl lipid A (MPL) and imiquimod (IMQ) were used as TLR ligands adjuvants to enhance immunogenicity and rate of protection against leishmaniasis. Nanoliposomes containing soluble Leishmania antigens (SLA) and adjuvants were consisted of DSPC, DSPG and Chol prepared by using lipid film method followed by bath sonication. The size of nanoliposomes was around 95 nm and their zeta potential was negative. BALB/c mice were immunized by liposomal formulations of lip/SLA, lip/MPL/SLA, lip/IMQ/SLA, lip/MPL/IMQ/SLA, lip/SLA + lip/IMQ, lip/SLA + lip/MPL, lip/SLA + lip/MPL/IMQ and five controls of SLA, lip/MPL, lip/IMQ, lip/MPL/IMQ and buffer by subcutaneously (SC) injections, three times in 2 weeks intervals. The synergic effect of two adjuvants when they are used in one formulation showed significantly (p MPL and IMQ adjuvants and antigen in nanoliposome carrier could be an appropriate delivery system to induce cellular immunity pathway against leishmaniasis.

  18. High throughput production of mouse monoclonal antibodies using antigen microarrays

    DEFF Research Database (Denmark)

    De Masi, Federico; Chiarella, P.; Wilhelm, H.

    2005-01-01

    Recent advances in proteomics research underscore the increasing need for high-affinity monoclonal antibodies, which are still generated with lengthy, low-throughput antibody production techniques. Here we present a semi-automated, high-throughput method of hybridoma generation and identification....... Monoclonal antibodies were raised to different targets in single batch runs of 6-10 wk using multiplexed immunisations, automated fusion and cell-culture, and a novel antigen-coated microarray-screening assay. In a large-scale experiment, where eight mice were immunized with ten antigens each, we generated...

  19. Targeting dendritic cells in vivo for cancer therapy

    Directory of Open Access Journals (Sweden)

    Irina eCaminschi

    2012-02-01

    Full Text Available Monoclonal antibodies that recognise cell surface molecules have been used deliver antigenic cargo to dendritic cells (DC for induction of immune responses. The encouraging anti-tumour immunity elicited using this immunisation strategy suggests its suitability for clinical trials. This review discusses the complex network of DC, the functional specialisation of DC-subsets, the immunological outcomes of targeting different DC-subsets and their cell surface receptors, and the requirements for the induction of effective anti-tumour immunity. Finally, we review preclinical experiments and the progress towards targeting human DC in vivo.

  20. Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells

    Directory of Open Access Journals (Sweden)

    Isabel Correa

    2018-03-01

    Full Text Available Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1 specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires.

  1. Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells.

    Science.gov (United States)

    Correa, Isabel; Ilieva, Kristina M; Crescioli, Silvia; Lombardi, Sara; Figini, Mariangela; Cheung, Anthony; Spicer, James F; Tutt, Andrew N J; Nestle, Frank O; Karagiannis, Panagiotis; Lacy, Katie E; Karagiannis, Sophia N

    2018-01-01

    Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα) as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1) specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs) were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires.

  2. Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells

    Science.gov (United States)

    Correa, Isabel; Ilieva, Kristina M.; Crescioli, Silvia; Lombardi, Sara; Figini, Mariangela; Cheung, Anthony; Spicer, James F.; Tutt, Andrew N. J.; Nestle, Frank O.; Karagiannis, Panagiotis; Lacy, Katie E.; Karagiannis, Sophia N.

    2018-01-01

    Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα) as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1) specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs) were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires. PMID:29628923

  3. Pathogens Inactivated by Low-Energy-Electron Irradiation Maintain Antigenic Properties and Induce Protective Immune Responses

    Science.gov (United States)

    Fertey, Jasmin; Bayer, Lea; Grunwald, Thomas; Pohl, Alexandra; Beckmann, Jana; Gotzmann, Gaby; Casado, Javier Portillo; Schönfelder, Jessy; Rögner, Frank-Holm; Wetzel, Christiane; Thoma, Martin; Bailer, Susanne M.; Hiller, Ekkehard; Rupp, Steffen; Ulbert, Sebastian

    2016-01-01

    Inactivated vaccines are commonly produced by incubating pathogens with chemicals such as formaldehyde or β-propiolactone. This is a time-consuming process, the inactivation efficiency displays high variability and extensive downstream procedures are often required. Moreover, application of chemicals alters the antigenic components of the viruses or bacteria, resulting in reduced antibody specificity and therefore stimulation of a less effective immune response. An alternative method for inactivation of pathogens is ionizing radiation. It acts very fast and predominantly damages nucleic acids, conserving most of the antigenic structures. However, currently used irradiation technologies (mostly gamma-rays and high energy electrons) require large and complex shielding constructions to protect the environment from radioactivity or X-rays generated during the process. This excludes them from direct integration into biological production facilities. Here, low-energy electron irradiation (LEEI) is presented as an alternative inactivation method for pathogens in liquid solutions. LEEI can be used in normal laboratories, including good manufacturing practice (GMP)- or high biosafety level (BSL)-environments, as only minor shielding is necessary. We show that LEEI efficiently inactivates different viruses (influenza A (H3N8), porcine reproductive and respiratory syndrome virus (PRRSV), equine herpesvirus 1 (EHV-1)) and bacteria (Escherichia coli) and maintains their antigenicity. Moreover, LEEI-inactivated influenza A viruses elicit protective immune responses in animals, as analyzed by virus neutralization assays and viral load determination upon challenge. These results have implications for novel ways of developing and manufacturing inactivated vaccines with improved efficacy. PMID:27886076

  4. Detection of Immune-Complex Dissociated Nonstructural-1 (NS-1) Antigen in Patients with Acute Dengue Virus Infections

    NARCIS (Netherlands)

    P. Koraka (Penelope); C.P. Burghoorn-Maas; A. Falconar; T.E. Setiati (Tatty); K. Djamiatun; J. Groen (Jan); A.D.M.E. Osterhaus (Albert)

    2003-01-01

    textabstractAccurate and timely diagnosis of dengue virus (DEN) infections is essential for the differential diagnosis of patients with febrile illness and hemorrhagic fever. In the present study, the diagnostic value of a newly developed immune-complex dissociated nonstructural-1 (NS-1) antigen dot

  5. Lipopolysaccharide contamination of beta-lactoglobulin affects the immune response against intraperitoneally and orally administered antigen

    DEFF Research Database (Denmark)

    Pedersen, Susanne Brix; Kjær, T.M.R.; Barkholt, Vibeke

    2004-01-01

    Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram- negative bacteria, is extensively present in food products like co......-LG was contaminated with LPS. Conclusions: LPS contamination of an aqueous protein solution does not affect oral tolerance induction, whereas LPS present in emulsion prevents oral tolerance induction towards the food protein.......Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram- negative bacteria, is extensively present in food products like cow......'s milk. It is not well established, however, how this presence of LPS affects oral tolerance induction. Methods: We studied the effect of LPS contamination in a commercial preparation of the cow milk protein beta-lactoglobulin (beta-LG) on antigen-specific immune responses. IgG1/IgG2a production upon...

  6. Understanding original antigenic sin in influenza with a dynamical system.

    Science.gov (United States)

    Pan, Keyao

    2011-01-01

    Original antigenic sin is the phenomenon in which prior exposure to an antigen leads to a subsequent suboptimal immune response to a related antigen. Immune memory normally allows for an improved and rapid response to antigens previously seen and is the mechanism by which vaccination works. I here develop a dynamical system model of the mechanism of original antigenic sin in influenza, clarifying and explaining the detailed spin-glass treatment of original antigenic sin. The dynamical system describes the viral load, the quantities of healthy and infected epithelial cells, the concentrations of naïve and memory antibodies, and the affinities of naïve and memory antibodies. I give explicit correspondences between the microscopic variables of the spin-glass model and those of the present dynamical system model. The dynamical system model reproduces the phenomenon of original antigenic sin and describes how a competition between different types of B cells compromises the overall effect of immune response. I illustrate the competition between the naïve and the memory antibodies as a function of the antigenic distance between the initial and subsequent antigens. The suboptimal immune response caused by original antigenic sin is observed when the host is exposed to an antigen which has intermediate antigenic distance to a second antigen previously recognized by the host's immune system.

  7. Dynamic visualization of dendritic cell-antigen interactions in the skin following transcutaneous immunization.

    Directory of Open Access Journals (Sweden)

    Teerawan Rattanapak

    Full Text Available Delivery of vaccines into the skin provides many advantages over traditional parenteral vaccination and is a promising approach due to the abundance of antigen presenting cells (APC residing in the skin including Langerhans cells (LC and dermal dendritic cells (DDC. However, the main obstacle for transcutaneous immunization (TCI is the effective delivery of the vaccine through the stratum corneum (SC barrier to the APC in the deeper skin layers. This study therefore utilized microneedles (MN and a lipid-based colloidal delivery system (cubosomes as a synergistic approach for the delivery of vaccines to APC in the skin. The process of vaccine uptake and recruitment by specific types of skin APC was investigated in real-time over 4 hours in B6.Cg-Tg (Itgax-EYFP 1 Mnz/J mice by two-photon microscopy. Incorporation of the vaccine into a particulate delivery system and the use of MN preferentially increased vaccine antigen uptake by a highly motile subpopulation of skin APC known as CD207⁺ DC. No uptake of antigen or any response to immunisation by LC could be detected.

  8. Th1 immune response to Plasmodium falciparum recombinant thrombospondin-related adhesive protein (TRAP) antigen is enhanced by TLR3-specific adjuvant, poly(I:C) in BALB/c mice.

    Science.gov (United States)

    Mehrizi, A A; Ameri Torzani, M; Zakeri, S; Jafary Zadeh, A; Babaeekhou, L

    2018-07-01

    Sporozoite-based malaria vaccines have provided a gold standard for malaria vaccine development, and thrombospondin-related adhesive protein (TRAP) serves as the main vaccine candidate antigen on sporozoites. As recombinant malaria vaccine candidate antigens are poorly immunogenic, additional appropriate immunostimulants, such as an efficient adjuvant, are highly essential to modulate Th1-cell predominance and also to induce a protective and long-lived immune response. In this study, polyinosinic:polycytidylic acid [poly(I:C)], the ligand of TLR3, was considered as the potential adjuvant for vaccines targeting stronger Th1-based immune responses. For this purpose, BALB/c mice were immunized with rPfTRAP delivered in putative poly(I:C) adjuvant, and humoural and cellular immune responses were determined in different immunized mouse groups. Delivery of rPfTRAP with poly(I:C) induced high levels and titres of persisted and also high-avidity anti-rPfTRAP IgG antibodies comparable to complete Freund's adjuvant (CFA)/incomplete Freund's adjuvant (IFA) adjuvant after the second boost. In addition, rPfTRAP formulated with poly(I:C) elicited a higher ratio of IFN-γ/IL-5, IgG2a/IgG1, and IgG2b/IgG1 than with CFA/IFA, indicating that poly(I:C) supports the induction of a stronger Th1-based immune response. This is a first time study which reveals the potential of rPfTRAP delivery in poly(I:C) to increase the level, avidity and durability of both anti-PfTRAP cytophilic antibodies and Th1 cytokines. © 2018 John Wiley & Sons Ltd.

  9. Enhancement of anti-murine colon cancer immunity by fusion of a SARS fragment to a low-immunogenic carcinoembryonic antigen

    Directory of Open Access Journals (Sweden)

    Lin Chen-Si

    2012-02-01

    Full Text Available Abstract Background It is widely understood that tumor cells express tumor-associated antigens (TAAs, of which many are usually in low immunogenicity; for example, carcinoembryonic antigen (CEA is specifically expressed on human colon cancer cells and is viewed as a low-immunogenic TAA. How to activate host immunity against specific TAAs and to suppress tumor growth therefore becomes important in cancer therapy development. Results To enhance the immune efficiency of CEA in mice that received, we fused a partial CEA gene with exogenous SARS-CoV fragments. Oral vaccination of an attenuated Salmonella typhimurium strain transformed with plasmids encoding CEA-SARS-CoV fusion gene into BALB/c mice elicited significant increases in TNF-α and IL-10 in the serum. In addition, a smaller tumor volume was observed in CT26/CEA-bearing mice who received CEA-SARS-CoV gene therapy in comparison with those administered CEA alone. Conclusion The administration of fusing CEA-SARS-CoV fragments may provide a promising strategy for strengthening the anti-tumor efficacy against low-immunogenic endogenous tumor antigens.

  10. 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.

  11. A yeast model for the mechanism of the Epstein-Barr virus immune evasion identifies a new therapeutic target to interfere with the virus stealthiness

    Directory of Open Access Journals (Sweden)

    KaMaría José Lista

    2017-08-01

    Full Text Available The oncogenic Epstein-Barr virus (EBV evades the im-mune system but has an Achilles heel: its genome maintenance protein EBNA1. Indeed, EBNA1 is essential for viral genome replication and maintenance but also highly antigenic. Hence, EBV evolved a system in which the glycine-alanine repeat (GAr of EBNA1 limits the translation of its own mRNA at a minimal level to ensure its essential function thereby, at the same time, minimizing immune recognition. Defining intervention points where to interfere with EBNA1 immune evasion is an important step to trigger an immune response against EBV-carrying cancers. Thanks to a yeast-based assay that recapitulates all the aspects of EBNA1 self-limitation of expression, a recent study by Lista et al. [Nature Communications (2017 7, 435-444] has un-covered the role of the host cell nucleolin (NCL in this process via a direct interaction of this protein with G-quadruplexes (G4 formed in GAr-encoding sequence of EBNA1 mRNA. In addition, the G4 ligand PhenDC3 prevents NCL binding on EBNA1 mRNA and reverses GAr-mediated repression of translation and antigen presentation. This shows that the NCL-EBNA1 mRNA interaction is a relevant therapeutic target to unveil EBV-carrying cancers to the immune system and that the yeast model can be successfully used for uncovering drugs and host factors that interfere with EBV stealthiness.

  12. Oral immune therapy: targeting the systemic immune system via the gut immune system for the treatment of inflammatory bowel disease.

    Science.gov (United States)

    Ilan, Yaron

    2016-01-01

    Inflammatory bowel diseases (IBD) are associated with an altered systemic immune response leading to inflammation-mediated damage to the gut and other organs. Oral immune therapy is a method of systemic immune modulation via alteration of the gut immune system. It uses the inherit ability of the innate system of the gut to redirect the systemic innate and adaptive immune responses. Oral immune therapy is an attractive clinical approach to treat autoimmune and inflammatory disorders. It can induce immune modulation without immune suppression, has minimal toxicity and is easily administered. Targeting the systemic immune system via the gut immune system can serve as an attractive novel therapeutic method for IBD. This review summarizes the current data and discusses several examples of oral immune therapeutic methods for using the gut immune system to generate signals to reset systemic immunity as a treatment for IBD.

  13. Low antigen dose formulated in CAF09 adjuvant Favours a cytotoxic T-cell response following intraperitoneal immunization in Göttingen minipigs

    DEFF Research Database (Denmark)

    Overgaard, Nana Haahr; Frøsig, Thomas Mørch; Jakobsen, Jeanne Toft

    2017-01-01

    in order to generate a certain type of immune response. To investigate this area further, we used Göttingen minipigs asan animal model especially due to the similar body size and high degree of immunome similarity between humans and pigs. In this study, we show that both a humoral and a cell......-dose immunization. Independent of antigen dose, intraperitoneal administration of antigen increased the amount of TT-specific cytotoxic CD8β+ T cells within the cytokine-producing T-cell pool when compared to the non-cytokine producing T-cell compartment. Taken together, these results demonstrate that a full...... protein formulated in the CAF09 adjuvant and administered to pigs via the intraperitoneal route effectively generates a cytotoxic T-cell response. Moreover, we confirm the inverse relationship between the antigen dose and the induction of polyfunctional T cells in a large animal model. These finding can...

  14. IL-4Rα-associated antigen processing by B cells promotes immunity in Nippostrongylus brasiliensis infection.

    Directory of Open Access Journals (Sweden)

    William G C Horsnell

    2013-10-01

    Full Text Available In this study, B cell function in protective T(H2 immunity against N. brasiliensis infection was investigated. Protection against secondary infection depended on IL-4Rα and IL-13; but not IL-4. Protection did not associate with parasite specific antibody responses. Re-infection of B cell-specific IL-4Rα⁻/⁻ mice resulted in increased worm burdens compared to control mice, despite their equivalent capacity to control primary infection. Impaired protection correlated with reduced lymphocyte IL-13 production and B cell MHC class II and CD86 surface expression. Adoptive transfer of in vivo N. brasiliensis primed IL-4Rα expressing B cells into naïve BALB/c mice, but not IL-4Rα or IL-13 deficient B cells, conferred protection against primary N. brasiliensis infection. This protection required MHC class II compatibility on B cells suggesting cognate interactions by B cells with CD4⁺ T cells were important to co-ordinate immunity. Furthermore, the rapid nature of these protective effects by B cells suggested non-BCR mediated mechanisms, such as via Toll Like Receptors, was involved, and this was supported by transfer experiments using antigen pulsed Myd88⁻/⁻ B cells. These data suggest TLR dependent antigen processing by IL-4Rα-responsive B cells producing IL-13 contribute significantly to CD4⁺ T cell-mediated protective immunity against N. brasiliensis infection.

  15. 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.

  16. PROSTVAC® targeted immunotherapy candidate for prostate cancer.

    Science.gov (United States)

    Shore, Neal D

    2014-01-01

    Targeted immunotherapies represent a valid strategy for the treatment of metastatic castrate-resistant prostate cancer. A randomized, double-blind, Phase II clinical trial of PROSTVAC® demonstrated a statistically significant improvement in overall survival and a large, global, Phase III trial with overall survival as the primary end point is ongoing. PROSTVAC immunotherapy contains the transgenes for prostate-specific antigen and three costimulatory molecules (designated TRICOM). Research suggests that PROSTVAC not only targets prostate-specific antigen, but also other tumor antigens via antigen cascade. PROSTVAC is well tolerated and has been safely combined with other cancer therapies, including hormonal therapy, radiotherapy, another immunotherapy and chemotherapy. Even greater benefits of PROSTVAC may be recognized in earlier-stage disease and low-disease burden settings where immunotherapy can trigger a long-lasting immune response.

  17. 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

  18. Anthrax lethal factor as an immune target in humans and transgenic mice and the impact of HLA polymorphism on CD4+ T cell immunity.

    Science.gov (United States)

    Ascough, Stephanie; Ingram, Rebecca J; Chu, Karen K; Reynolds, Catherine J; Musson, Julie A; Doganay, Mehmet; Metan, Gökhan; Ozkul, Yusuf; Baillie, Les; Sriskandan, Shiranee; Moore, Stephen J; Gallagher, Theresa B; Dyson, Hugh; Williamson, E Diane; Robinson, John H; Maillere, Bernard; Boyton, Rosemary J; Altmann, Daniel M

    2014-05-01

    Bacillus anthracis produces a binary toxin composed of protective antigen (PA) and one of two subunits, lethal factor (LF) or edema factor (EF). Most studies have concentrated on induction of toxin-specific antibodies as the correlate of protective immunity, in contrast to which understanding of cellular immunity to these toxins and its impact on infection is limited. We characterized CD4+ T cell immunity to LF in a panel of humanized HLA-DR and DQ transgenic mice and in naturally exposed patients. As the variation in antigen presentation governed by HLA polymorphism has a major impact on protective immunity to specific epitopes, we examined relative binding affinities of LF peptides to purified HLA class II molecules, identifying those regions likely to be of broad applicability to human immune studies through their ability to bind multiple alleles. Transgenics differing only in their expression of human HLA class II alleles showed a marked hierarchy of immunity to LF. Immunogenicity in HLA transgenics was primarily restricted to epitopes from domains II and IV of LF and promiscuous, dominant epitopes, common to all HLA types, were identified in domain II. The relevance of this model was further demonstrated by the fact that a number of the immunodominant epitopes identified in mice were recognized by T cells from humans previously infected with cutaneous anthrax and from vaccinated individuals. The ability of the identified epitopes to confer protective immunity was demonstrated by lethal anthrax challenge of HLA transgenic mice immunized with a peptide subunit vaccine comprising the immunodominant epitopes that we identified.

  19. 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.

  20. Aspects of the immune response against proteic antigens submitted to the effects of 60Co gamma radiation

    International Nuclear Information System (INIS)

    Alves, Janaina Baptista.

    2004-01-01

    Considering the effects of gamma radiation on proteins and the capacity of the immune system to recognize modified macromolecules, we decided to evaluate some immunological aspects of B10.PL mice exposed to native or irradiated ovalbumin and bothrops toxin-1 (BthTx-1). In order to evaluate possible structural modifications of the molecules after being irradiated ( 60 Co gamma rays), bothrops toxin-1 was analysed by electrophoresis, while ovalbumin was submitted to analytical size exclusion chromatography. The toxin was also analysed by ESI-mass spectrometry. Our results indicate that radiation promoted modifications on both the molecules. Aiming to compare the toxicity of the native and irradiated forms of the toxin, an in vitro cytotoxicity assay, using CHO cells, was performed. According to our results, the modified toxin was 5 folds less toxic than its native counterpart. Sera of animals immunized with the native and irradiated proteins were analyzed in order to evaluate levels of IgG, as well as to quantify specific isotopes. While the native proteins induced a predominant Th2 response, the irradiated molecules apparently promoted a switch towards a Th1 pattern. We also performed a cell proliferation assay with splenocytes from mice immunized with either the native or the irradiated proteins, cultured in the presence of the antigens. Our results indicate that both the forms of the proteins induced a similar proliferative response. These data indicate a potential use of detoxified proteins as antigens for immunization. (author)

  1. Immunization with Pre-Erythrocytic Antigen CelTOS from Plasmodium falciparum Elicits Cross-Species Protection against Heterologous Challenge with Plasmodium berghei

    Science.gov (United States)

    2010-08-01

    or the early liver-stages of the mammalian life cycle . One of these antigens is the cell-traversal protein for ookinetes and sporozoites (CelTOS...Immunization with Pre-Erythrocytic Antigen CelTOS from Plasmodium falciparum Elicits Cross-Species Protection against Heterologous Challenge with... Plasmodium berghei Elke S. Bergmann-Leitner1*, Ryan M. Mease1, Patricia De La Vega1, Tatyana Savranskaya2, Mark Polhemus1, Christian Ockenhouse1, Evelina

  2. Molecular mimics of the tumour antigen MUC1.

    Directory of Open Access Journals (Sweden)

    Tharappel C James

    Full Text Available A key requirement for the development of cancer immunotherapy is the identification of tumour-associated antigens that are differentially or exclusively expressed on the tumour and recognized by the host immune system. However, immune responses to such antigens are often muted or lacking due to the antigens being recognized as "self", and further complicated by the tumour environment and regulation of immune cells within. In an effort to circumvent the lack of immune responses to tumour antigens, we have devised a strategy to develop potential synthetic immunogens. The strategy, termed mirror image phage display, is based on the concept of molecular mimicry as demonstrated by the idiotype/anti-idiotype paradigm in the immune system. Here as 'proof of principle' we have selected molecular mimics of the well-characterised tumour associated antigen, the human mucin1 protein (MUC1 from two different peptide phage display libraries. The putative mimics were compared in structure and function to that of the native antigen. Our results demonstrate that several of the mimic peptides display T-cell stimulation activity in vitro when presented by matured dendritic cells. The mimic peptides and the native MUC1 antigenic epitopes can cross-stimulate T-cells. The data also indicate that sequence homology and/or chemical properties to the original epitope are not the sole determining factors for the observed immunostimulatory activity of the mimic peptides.

  3. Human CD3+ T-Cells with the Anti-ERBB2 Chimeric Antigen Receptor Exhibit Efficient Targeting and Induce Apoptosis in ERBB2 Overexpressing Breast Cancer Cells

    Science.gov (United States)

    Munisvaradass, Rusheni; Kumar, Suresh; Govindasamy, Chandramohan; Alnumair, Khalid S.; Mok, Pooi Ling

    2017-01-01

    Breast cancer is a common malignancy among women. The innate and adaptive immune responses failed to be activated owing to immune modulation in the tumour microenvironment. Decades of scientific study links the overexpression of human epidermal growth factor receptor 2 (ERBB2) antigen with aggressive tumours. The Chimeric Antigen Receptor (CAR) coding for specific tumour-associated antigens could initiate intrinsic T-cell signalling, inducing T-cell activation, and cytotoxic activity without the need for major histocompatibility complex recognition. This renders CAR as a potentially universal immunotherapeutic option. Herein, we aimed to establish CAR in CD3+ T-cells, isolated from human peripheral blood mononucleated cells that could subsequently target and induce apoptosis in the ERBB2 overexpressing human breast cancer cell line, SKBR3. Constructed CAR was inserted into a lentiviral plasmid containing a green fluorescent protein tag and produced as lentiviral particles that were used to transduce activated T-cells. Transduced CAR-T cells were then primed with SKBR3 cells to evaluate their functionality. Results showed increased apoptosis in SKBR3 cells co-cultured with CAR-T cells compared to the control (non–transduced T-cells). This study demonstrates that CAR introduction helps overcome the innate limitations of native T-cells leading to cancer cell apoptosis. We recommend future studies should focus on in vivo cytotoxicity of CAR-T cells against ERBB2 expressing tumours. PMID:28885562

  4. Gamma irradiated antigen extracts improves the immune response and protection in experimental toxoplasmosis

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Andrea da; Galisteo Junior, Andres Jimenez; Andrade Junior, Heitor Franco de, E-mail: andreacosta@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Medicina Tropical; Zorgi, Nahiara Estevez [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Ciencias Biomedicas; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    We aimed to use ionizing radiation on soluble extracts of T. gondii tachyzoites (AgTg) and tested the ability of these extracts to induce immunity in BALB/c mice against a challenge. T. gondii RH strain AgTg was irradiated with Co-60 at 0.25 to 4 kGy and were affected after 1 kGy, as evidenced by a progressive high molecular weight protein aggregates and no loss in antigenicity, as detected by immunoblotting, except after 4kGy. BALB/c mice were immunized with biweekly doses of 03 s.c. native or irradiated AgTg without adjuvants; the anti-T.gondii IgG production was detected by ELISA, and higher levels and avidity were detected in mice immunized with 1.5 kGy AgTg compared to controls (p<0.05). Mice immunized with native AgTg exhibited spleen CD19{sup +} B, CD3{sup +}CD4{sup +} or CD3{sup +}CD8{sup +} T cell proliferation levels of 5%, while 1.5 kGy-immunized mice exhibited spleen cell proliferation levels of 12.2%, primarily for CD19{sup +} or CD3{sup +}CD8{sup +} lymphocytes and less evidently for CD3{sup +}CD4{sup +} (8.8%) helper T lymphocytes. All cells from control mice showed little to no proliferation when stimulated with AgTg. These cells secreted more IFN-γ in the 1.5 kGy AgTg-immunized group (p<0.05). BALB/c mice immunized with 1.5 kGy and challenged with different strains of T. gondii were partially protected, as evidenced by survival after RH virulent strain challenge (p<0.0001) but also after ME-49 strain challenge: the brain cyst numbers (p<0.05) and the levels of T. gondii DNA measured by real-time PCR (p<0.05) decreased compared to non-immunized controls. (author)

  5. Gamma irradiated antigen extracts improves the immune response and protection in experimental toxoplasmosis

    International Nuclear Information System (INIS)

    Costa, Andrea da; Galisteo Junior, Andres Jimenez; Andrade Junior, Heitor Franco de

    2015-01-01

    We aimed to use ionizing radiation on soluble extracts of T. gondii tachyzoites (AgTg) and tested the ability of these extracts to induce immunity in BALB/c mice against a challenge. T. gondii RH strain AgTg was irradiated with Co-60 at 0.25 to 4 kGy and were affected after 1 kGy, as evidenced by a progressive high molecular weight protein aggregates and no loss in antigenicity, as detected by immunoblotting, except after 4kGy. BALB/c mice were immunized with biweekly doses of 03 s.c. native or irradiated AgTg without adjuvants; the anti-T.gondii IgG production was detected by ELISA, and higher levels and avidity were detected in mice immunized with 1.5 kGy AgTg compared to controls (p<0.05). Mice immunized with native AgTg exhibited spleen CD19 + B, CD3 + CD4 + or CD3 + CD8 + T cell proliferation levels of 5%, while 1.5 kGy-immunized mice exhibited spleen cell proliferation levels of 12.2%, primarily for CD19 + or CD3 + CD8 + lymphocytes and less evidently for CD3 + CD4 + (8.8%) helper T lymphocytes. All cells from control mice showed little to no proliferation when stimulated with AgTg. These cells secreted more IFN-γ in the 1.5 kGy AgTg-immunized group (p<0.05). BALB/c mice immunized with 1.5 kGy and challenged with different strains of T. gondii were partially protected, as evidenced by survival after RH virulent strain challenge (p<0.0001) but also after ME-49 strain challenge: the brain cyst numbers (p<0.05) and the levels of T. gondii DNA measured by real-time PCR (p<0.05) decreased compared to non-immunized controls. (author)

  6. Exosomes and their roles in immune regulation and cancer.

    Science.gov (United States)

    Greening, David W; Gopal, Shashi K; Xu, Rong; Simpson, Richard J; Chen, Weisan

    2015-04-01

    Exosomes, a subset of extracellular vesicles (EVs), function as a mode of intercellular communication and molecular transfer. Exosomes facilitate the direct extracellular transfer of proteins, lipids, and miRNA/mRNA/DNAs between cells in vitro and in vivo. The immunological activities of exosomes affect immunoregulation mechanisms including modulating antigen presentation, immune activation, immune suppression, immune surveillance, and intercellular communication. Besides immune cells, cancer cells secrete immunologically active exosomes that influence both physiological and pathological processes. The observation that exosomes isolated from immune cells such as dendritic cells (DCs) modulate the immune response has enforced the way these membranous vesicles are being considered as potential immunotherapeutic reagents. Indeed, tumour- and immune cell-derived exosomes have been shown to carry tumour antigens and promote immunity, leading to eradication of established tumours by CD8(+) T cells and CD4(+) T cells, as well as directly suppressing tumour growth and resistance to malignant tumour development. Further understanding of these areas of exosome biology, and especially of molecular mechanisms involved in immune cell targeting, interaction and manipulation, is likely to provide significant insights into immunorecognition and therapeutic intervention. Here, we review the emerging roles of exosomes in immune regulation and the therapeutic potential in cancer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Cancer-Targeted Oncolytic Adenoviruses for Modulation of the Immune System.

    Science.gov (United States)

    Cerullo, Vincenzo; Capasso, Cristian; Vaha-Koskela, Markus; Hemminki, Otto; Hemminki, Akseli

    2018-01-01

    Adenovirus is one of the most commonly used vectors for gene therapy and it is the first approved virus-derived drug for treatment of cancer. As an oncolytic agent, it can induce lysis of infected cells, but it can also engage the immune system, promoting activation and maturation of antigen- presenting cells (APCs). In essence, oncolysis combined with the associated immunostimulatory actions result in a "personalized in situ vaccine" for each patient. In order to take full advantage of these features, we should try to understand how adenovirus interacts with the immune system, what are the receptors involved in triggering subsequent signals and which kind of responses they elicit. Tackling these questions will give us further insight in how to manipulate adenovirus-mediated immune responses for enhancement of anti-tumor efficacy. In this review, we first highlight how oncolytic adenovirus interacts with the innate immune system and its receptors such as Toll-like receptors, nucleotide-binding and oligomerization domain (NOD)- like receptors and other immune sensors. Then we describe the effect of these interactions on the adaptive immune system and its cells, especially B and T lymphocytes. Finally, we summarize the most significant preclinical and clinical results in the field of gene therapy where researchers have engineered adenovirus to manipulate the host immune system by expressing cytokines and signalingmediators. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Antigen delivery by α2-macroglobulin enhances the cytotoxic T lymphocyte response

    Science.gov (United States)

    Bowers, Edith V.; Horvath, Jeffrey J.; Bond, Jennifer E.; Cianciolo, George J.; Pizzo, Salvatore V.

    2009-01-01

    α2M* targets antigens to APCs for rapid internalization, processing, and presentation. When used as an antigen-delivery vehicle, α2M* amplifies MHC class II presentation, as demonstrated by increased antibody titers. Recent evidence, however, suggests that α2M* encapsulation may also enhance antigen-specific CTL immunity. In this study, we demonstrate that α2M*-delivered antigen (OVA) enhances the production of specific in vitro and in vivo CTL responses. Murine splenocytes expressing a transgenic TCR specific for CTL peptide OVA257–264 (SIINFEKL) demonstrated up to 25-fold greater IFN-γ and IL-2 secretion when treated in vitro with α2M*-OVA compared with soluble OVA. The frequency of IFN-γ-producing cells was increased ∼15-fold, as measured by ELISPOT. Expansion of the OVA-specific CD8+ T cell population, as assayed by tetramer binding and [3H]thymidine incorporation, and OVA-specific cell-mediated cytotoxicity, as determined by a flow cytometric assay, were also enhanced significantly by α2M*-OVA. Furthermore, significant CTL responses were observed at antigen doses tenfold lower than those required with OVA alone. Finally, we also observed enhanced humoral and CTL responses by naïve mice following intradermal immunization with α2M*-OVA. These α2M*-OVA-immunized mice demonstrated increased protection against a s.c.-implanted, OVA-expressing tumor, as demonstrated by delayed tumor growth and prolonged animal survival. The observation that α2M*-mediated antigen delivery elicits specific CTL responses suggests the cross-presentation of antigen onto MHC class I. These results support α2M* as an effective antigen-delivery system that may be particularly useful for vaccines based on weakly immunogenic subunits or requiring dose sparing. PMID:19652028

  9. Prostate Stem Cell Antigen: A Prospective Therapeutic and Diagnostic Target

    Science.gov (United States)

    Raff, Adam B.; Gray, Andrew; Kast, W. Martin

    2009-01-01

    The development of novel clinical tools to combat cancer is an intense field of research and recent efforts have been directed at the identification of proteins that may provide diagnostic, prognostic and/or therapeutic applications due to their restricted expression. To date, a number of protein candidates have emerged as potential clinical tools in the treatment of prostate cancer. Discovered over ten year ago, prostate stem cell antigen (PSCA) is a cell surface antigen that belongs to the Ly-6/Thy-1 family of glycosylphosphatidylinositol-anchored proteins. PSCA is highly overexpressed in human prostate cancer, with limited expression in normal tissues, making it an ideal target for both diagnosis and therapy. Several studies have now clearly correlated the expression of PSCA with relevant clinical benchmarks, such as Gleason score and metastasis, while others have demonstrated the efficacy of PSCA targeting in treatment through various modalities. The purpose of this review is to present the current body of knowledge about PSCA and its potential role in the treatment of human prostate cancer. PMID:18838214

  10. A imunidade na febre tifoide. II. Antigenos e resposta imune nas salmoneloses sistemicas Immunity in typhoid fever. II. Antigens and immune response in systemic salmonellosis

    Directory of Open Access Journals (Sweden)

    Arlete Moreira Milhomem

    1982-12-01

    Full Text Available Os resultados dos trabalhos acumulados a partir do início do século permitem concluir que, apesar de numerosos progressos e estudos dos pontos de vista químico, imunoquímico, genético e biológico, o (s antígeno (s responsável (is pela imunidade nas salmoneloses sistêmicas ainda não está (ao definido (s. As mais diversas preparações têm sido propostas como possiveis imunogenos, bem como uma ampla variedade de modelos experimentais e de métodos de avaliação da resposta imune. Em relacao ao primeiro aspecto, sendo a Salmonella typhi, em condições naturais, um patógeno exclusivo do homem, os resultados obtidos em animais de laboratório frequentemente não se correlacionaram com os obtidos em seres humanos. Salienta-se que a pesquisa da resposta imune tem sido limitada na maioria das vezes a avaliação do titulo de aglutininas para os antigenos O, H e Vi; ou a testes de proteção passiva ou ativa em camundongos. A imunidade celular tem sido definida, principalmente por testes cutâneos, com preparações de natureza proteica, de composição variável e estrutura quimica mal-definida. Todos os dados revistos levam a conclusão de que até o presente, ignora-se o, ou os mecanismos de imunoproteção nas salmoneloses sistemicas.The results of the work done from the beginning of the century up to the present were reviewed, leading to the conclusion that the large amount of available knowledge on the chemistry, immunological, antigenic, and biological aspects of the antigens of Salmonella, was not sufficient to determine which antigen(s accounted for immune protection on systemic salmonellosis. Data accumulated on numerous and diversified preparations being used as immunogens, as well as on several experimental models and different methods of studying the immune response. In relation to Salmonella typhi, given that this microorganism is an exclusive natural pathogen only for man, the results of protection obtained with laboratory

  11. “New” Antigenic Targets and Methodological Approaches for Refining Laboratory Diagnosis of Antiphospholipid Syndrome

    Science.gov (United States)

    Misasi, Roberta; Capozzi, Antonella; Longo, Agostina; Recalchi, Serena; Lococo, Emanuela; Alessandri, Cristiano; Conti, Fabrizio; Valesini, Guido

    2015-01-01

    Antiphospholipid antibodies (aPLs) are a heterogeneous group of antibodies directed against phospholipids or protein/phospholipid complexes. Currently, aPLs are assessed using either “solid-phase” assays that identify anticardiolipin antibodies and anti-β2-glycoprotein I antibodies or “liquid-phase” assay that identifies lupus anticoagulant. However, in the last few years, “new” antigenic targets and methodological approaches have been employed for refining laboratory diagnosis of antiphospholipid syndrome (APS). In this review the potential diagnostic value of antibodies to domains of β2-GPI, prothrombin/phosphatidylserine, vimentin/cardiolipin, protein S, protein C, annexin A2, annexin A5, and phospholipid antigens is discussed. Moreover, new technical approaches, including chemiluminescence, multiline dot assay, and thin layer chromatography (TLC) immunostaining, which utilize different supports for detection of aPL, have been developed. A special focus has been dedicated on “seronegative” APS, that is, those patients with a clinical profile suggestive of APS (thromboses, recurrent miscarriages, or foetal loss), who are persistently negative for the routinely used aPL. Recent findings suggest that, in sera from patients with SN-APS, antibodies may be detected using “new” antigenic targets (mainly vimentin/cardiolipin) or methodological approaches different from traditional techniques (TLC immunostaining). Thus, APS represents a mosaic, in which antibodies against different antigenic targets may be detected thanks to the continuously evolving new technologies. PMID:25874238

  12. Count of splenic stromal precursor cells in mice and expression of cytokine genes in these cells in primary cultures during different periods after immunization of animals with S. typhimurium antigens.

    Science.gov (United States)

    Gorskaya, Yu F; Danilova, T A; Mezentseva, M V; Shapoval, I M; Narovlyanskii, A N; Nesterenko, V G

    2011-06-01

    Injection of S. typhimurium antigens significantly (9-fold) increased cloning efficiency and, hence, the content of stromal precursor cells in the spleen as soon as after 24 h. These parameters returned to normal by days 6-15 after immunization. Cultured splenocytes collected from immune (but not intact) animals expressed the genes of proinflammatory cytokines IL-1β (on days 1, 6, 15) and IL-6 (on days 1 and 6), TNF-α (on days 6 and 15), and of IFN-α and IL-18 (on days 6 and 15). The expression of IL-4 gene was suppressed on day 6 after immunization, of IL-10 gene on days 1 and 6, of IL-6 gene on day 15. Hence, no signs of immune response suppression by stromal cells were found in this system. The spectrum and dynamics of the expression of pro- and anti-inflammatory cytokine genes in stromal cell cultures from the spleen of immunized mice seemed to correspond to those needed for support of the immune response to S. typhimurium antigens, observed in immunized animals. The results indicate possible involvement of stromal cells in the realization of immune response in vivo. The increase of stromal precursor cells cloning efficiency in response to antigen injection could not be reproduced in vitro: the presence of S. typhimurium antigens in primary cultures of intact mouse bone marrow and spleen throughout the entire period of culturing ≈ 20-fold reduced cloning efficiency in cultures.

  13. Regular Exercise Enhances the Immune Response Against Microbial Antigens Through Up-Regulation of Toll-like Receptor Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Qishi Zheng

    2015-09-01

    Full Text Available Background/Aims: Regular physical exercise can enhance resistance to many microbial infections. However, little is known about the mechanism underlying the changes in the immune system induced by regular exercise. Methods: We recruited members of a university badminton club as the regular exercise (RE group and healthy sedentary students as the sedentary control (SC group. We investigated the distribution of peripheral blood mononuclear cell (PBMC subsets and functions in the two groups. Results: There were no significant differences in plasma cytokine levels between the RE and SC groups in the true resting state. However, enhanced levels of IFN-γ, TNF-α, IL-6, IFN-α and IL-12 were secreted by PBMCs in the RE group following microbial antigen stimulation, when compared to the SC group. In contrast, the levels of TNF-α and IL-6 secreted by PBMC in the RE group were suppressed compared with those in SC group following non-microbial antigen stimulation (concanavalin A or α-galactosylceramide. Furthermore, PBMC expression of TLR2, TLR7 and MyD88 was significantly increased in the RE group in response to microbial antigen stimulation. Conclusion: Regular exercise enhances immune cell activation in response to pathogenic stimulation leading to enhanced cytokine production mediated via the TLR signaling pathways.

  14. 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.

  15. Targeting nanoparticles to dendritic cells for immunotherapy.

    NARCIS (Netherlands)

    Cruz, L.J.; Tacken, P.J.; Rueda, F.; Domingo, J.C.; Albericio, F.; Figdor, C.G.

    2012-01-01

    Dendritic cells (DCs) are key players in the initiation of adaptive immune responses and are currently exploited in immunotherapy for treatment of cancer and infectious diseases. Development of targeted nanodelivery systems carrying vaccine components, including antigens and adjuvants, to DCs in

  16. [Studies on calf salmonellosis. 4. Oral and parenteral immunization with live (Smd) and killed antigens].

    Science.gov (United States)

    Meyer, H; Steinbach, G; Hartmann, H; Hauke, H; Koch, H; Stelzner, A; Linde, K; Schmerbauch, A; Kiupel, H

    1977-01-01

    Reported are results obtained from studies into oral and parenteral immunisation of calf. The approaches had included the use of live (Smd) or dead antigen from Salmonella (S.) dublin and a combination of the two immunisation methods. Live antigen (Smd) was superior to thermally activated dead antigen, when the oral route was used to prevent S.-dublin injection of calves. The above findings were supported by results from analogous studies in which S. typhimurium and S. dublin or live antigen (Smd) or dead antigen, made of the two, had been applied to mice. (One single subcutaneous) parenteral administration did hardly reveal any difference in favour of live vaccine (Smd). Parenteral administration of live or dead antigen proved to be less effective than repeated oral immunisation, particularly when live vaccine (Smd) was used. Immunity not less than up to six months of age against S. dublin wild strain infection can be provided for young calves by oral immunisation, with Smd vaccine (5. 1010 to 1. 1011 live germs/d) being given on ten consecutive days. Calves orally immunised with live antigen (ten repetitive applications of Smd mutants) are likely to develop an antibody titre (H-agglutinins) against S. dublin. Parenteral boostering,using live antigen, has been accompanied by sensitisation due to oral live antigen administration as well as by dose dependence, as was seen from the bactericidal values. Sensitisation was established from orally immunised calves up to three months old (typical booster reaction). Some of it was attributabale to confrontation with wild strains of Salmonella. The H-agglutinin titres of animals aged threemonths in a calf herd with salmonelloses in which all animals had been orally Smd-immunised were close to those recorded from calves in stocks with no salmonellosis occurrence. Under the conditions of oral immunisation, there had obviously been no action of the wild strain which might have triggered intensive antibody formation.

  17. Unpolarized release of vaccinia virus and HIV antigen by colchicine treatment enhances intranasal HIV antigen expression and mucosal humoral responses.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available The induction of a strong mucosal immune response is essential to building successful HIV vaccines. Highly attenuated recombinant HIV vaccinia virus can be administered mucosally, but even high doses of immunization have been found unable to induce strong mucosal antibody responses. In order to solve this problem, we studied the interactions of recombinant HIV vaccinia virus Tiantan strain (rVTT-gagpol in mucosal epithelial cells (specifically Caco-2 cell layers and in BALB/c mice. We evaluated the impact of this virus on HIV antigen delivery and specific immune responses. The results demonstrated that rVTT-gagpol was able to infect Caco-2 cell layers and both the nasal and lung epithelia in BALB/c mice. The progeny viruses and expressed p24 were released mainly from apical surfaces. In BALB/c mice, the infection was limited to the respiratory system and was not observed in the blood. This showed that polarized distribution limited antigen delivery into the whole body and thus limited immune response. To see if this could be improved upon, we stimulated unpolarized budding of the virus and HIV antigens by treating both Caco-2 cells and BALB/c mice with colchicine. We found that, in BALB/c mice, the degree of infection and antigen expression in the epithelia went up. As a result, specific immune responses increased correspondingly. Together, these data suggest that polarized budding limits antigen delivery and immune responses, but unpolarized distribution can increase antigen expression and delivery and thus enhance specific immune responses. This conclusion can be used to optimize mucosal HIV vaccine strategies.

  18. Genetically modified anthrax lethal toxin safely delivers whole HIV protein antigens into the cytosol to induce T cell immunity

    Science.gov (United States)

    Lu, Yichen; Friedman, Rachel; Kushner, Nicholas; Doling, Amy; Thomas, Lawrence; Touzjian, Neal; Starnbach, Michael; Lieberman, Judy

    2000-07-01

    Bacillus anthrax lethal toxin can be engineered to deliver foreign proteins to the cytosol for antigen presentation to CD8 T cells. Vaccination with modified toxins carrying 8-9 amino acid peptide epitopes induces protective immunity in mice. To evaluate whether large protein antigens can be used with this system, recombinant constructs encoding several HIV antigens up to 500 amino acids were produced. These candidate HIV vaccines are safe in animals and induce CD8 T cells in mice. Constructs encoding gag p24 and nef stimulate gag-specific CD4 proliferation and a secondary cytotoxic T lymphocyte response in HIV-infected donor peripheral blood mononuclear cells in vitro. These results lay the foundation for future clinical vaccine studies.

  19. Macrophage Immune Response Suppression by Recombinant Mycobacterium tuberculosis Antigens, the ESAT-6, CFP-10, and ESAT-6/CFP-10 Fusion Proteins

    Science.gov (United States)

    Seghatoleslam, Atefeh; Hemmati, Mina; Ebadat, Saeedeh; Movahedi, Bahram; Mostafavi-Pour, Zohreh

    2016-01-01

    Background: Macrophage immune responses are affected by the secretory proteins of Mycobacterium tuberculosis (Mtb). This study aimed to examine the immune responses of macrophages to Mtb secretory antigens, namely ESAT-6, CFP-10, and ESAT-6/CFP-10. Methods: THP-1 cells (a human monocytic cell line) were cultured and differentiated to macrophages by phorbol 12-myristate 13-acetate. The cytotoxicity of the recombinant Mtb proteins was assessed using the MTT assay. Two important immune responses of macrophages, namely NO and ROS production, were measured in response to the ESAT-6, CFP-10, and ESAT-6/CFP-10 antigens. The data were analyzed using one-way ANOVA with SPSS, version 16, and considered significant at Pproteins markedly reduced macrophage immune response. The treatment of the THP-1-differentiated cells with ESAT-6, CFP-10, and ESAT-6/CFP-10 reduced NO and ROS production. The treated THP-1-differentiated cells exhibited less inducible NO synthase activity than did the untreated cells. No toxic effect on macrophage viability was observed for the applied proteins at the different concentrations. Conclusion: It seems that the decline in macrophage immune response is due to the suppression of NO and ROS production pathways without any effect on cell viability. PMID:27365551

  20. Simultaneous targeting of prostate stem cell antigen and prostate-specific membrane antigen improves the killing of prostate cancer cells using a novel modular T cell-retargeting system.

    Science.gov (United States)

    Arndt, Claudia; Feldmann, Anja; Koristka, Stefanie; Cartellieri, Marc; Dimmel, Maria; Ehninger, Armin; Ehninger, Gerhard; Bachmann, Michael

    2014-09-01

    Recently, we described a novel modular platform technology in which T cell-recruitment and tumor-targeting domains of conventional bispecific antibodies are split to independent components, a universal effector module (EM) and replaceable monospecific/monovalent target modules (TMs) that form highly efficient T cell-retargeting complexes. Theoretically, our unique strategy should allow us to simultaneously retarget T cells to different tumor antigens by combining the EM with two or more different monovalent/monospecific TMs or even with bivalent/bispecific TMs, thereby overcoming limitations of a monospecific treatment such as the selection of target-negative tumor escape variants. In order to advance our recently introduced prostate stem cell antigen (PSCA)-specific modular system for a dual-targeting of prostate cancer cells, two additional TMs were constructed: a monovalent/monospecific TM directed against the prostate-specific membrane antigen (PSMA) and a bivalent/bispecific TM (bsTM) with specificity for PSMA and PSCA. The functionality of the novel dual-targeting strategies was analyzed by performing T cell activation and chromium release assays. Similar to the PSCA-specific modular system, the novel PSMA-specific modular system mediates an efficient target-dependent and -specific tumor cell lysis at low E:T ratios and picomolar Ab concentrations. Moreover, by combination of the EM with either the bispecific TM directed to PSMA and PSCA or both monospecifc TMs directed to either PSCA or PSMA, dual-specific targeting complexes were formed which allowed us to kill potential escape variants expressing only one or the other target antigen. Overall, the novel modular system represents a promising tool for multiple tumor targeting. © 2014 Wiley Periodicals, Inc.

  1. Mechanisms of stage-transcending protection following immunization of mice with late liver stage-arresting genetically attenuated malaria parasites.

    Directory of Open Access Journals (Sweden)

    Brandon K Sack

    2015-05-01

    Full Text Available Malaria, caused by Plasmodium parasite infection, continues to be one of the leading causes of worldwide morbidity and mortality. Development of an effective vaccine has been encumbered by the complex life cycle of the parasite that has distinct pre-erythrocytic and erythrocytic stages of infection in the mammalian host. Historically, malaria vaccine development efforts have targeted each stage in isolation. An ideal vaccine, however, would target multiple life cycle stages with multiple arms of the immune system and be capable of eliminating initial infection in the liver, the subsequent blood stage infection, and would prevent further parasite transmission. We have previously shown that immunization of mice with Plasmodium yoelii genetically attenuated parasites (GAP that arrest late in liver stage development elicits stage-transcending protection against both a sporozoite challenge and a direct blood stage challenge. Here, we show that this immunization strategy engenders both T- and B-cell responses that are essential for stage-transcending protection, but the relative importance of each is determined by the host genetic background. Furthermore, potent anti-blood stage antibodies elicited after GAP immunization rely heavily on FC-mediated functions including complement fixation and FC receptor binding. These protective antibodies recognize the merozoite surface but do not appear to recognize the immunodominant merozoite surface protein-1. The antigen(s targeted by stage-transcending immunity are present in both the late liver stages and blood stage parasites. The data clearly show that GAP-engendered protective immune responses can target shared antigens of pre-erythrocytic and erythrocytic parasite life cycle stages. As such, this model constitutes a powerful tool to identify novel, protective and stage-transcending T and B cell targets for incorporation into a multi-stage subunit vaccine.

  2. EBNA1: Oncogenic Activity, Immune Evasion and Biochemical Functions Provide Targets for Novel Therapeutic Strategies against Epstein-Barr Virus- Associated Cancers

    Directory of Open Access Journals (Sweden)

    Joanna B. Wilson

    2018-04-01

    Full Text Available The presence of the Epstein-Barr virus (EBV-encoded nuclear antigen-1 (EBNA1 protein in all EBV-carrying tumours constitutes a marker that distinguishes the virus-associated cancer cells from normal cells and thereby offers opportunities for targeted therapeutic intervention. EBNA1 is essential for viral genome maintenance and also for controlling viral gene expression and without EBNA1, the virus cannot persist. EBNA1 itself has been linked to cell transformation but the underlying mechanism of its oncogenic activity has been unclear. However, recent data are starting to shed light on its growth-promoting pathways, suggesting that targeting EBNA1 can have a direct growth suppressing effect. In order to carry out its tasks, EBNA1 interacts with cellular factors and these interactions are potential therapeutic targets, where the aim would be to cripple the virus and thereby rid the tumour cells of any oncogenic activity related to the virus. Another strategy to target EBNA1 is to interfere with its expression. Controlling the rate of EBNA1 synthesis is critical for the virus to maintain a sufficient level to support viral functions, while at the same time, restricting expression is equally important to prevent the immune system from detecting and destroying EBNA1-positive cells. To achieve this balance EBNA1 has evolved a unique repeat sequence of glycines and alanines that controls its own rate of mRNA translation. As the underlying molecular mechanisms for how this repeat suppresses its own rate of synthesis in cis are starting to be better understood, new therapeutic strategies are emerging that aim to modulate the translation of the EBNA1 mRNA. If translation is induced, it could increase the amount of EBNA1-derived antigenic peptides that are presented to the major histocompatibility (MHC class I pathway and thus, make EBV-carrying cancers better targets for the immune system. If translation is further suppressed, this would provide another

  3. Phase variable O antigen biosynthetic genes control expression of the major protective antigen and bacteriophage receptor in Vibrio cholerae O1.

    Directory of Open Access Journals (Sweden)

    Kimberley D Seed

    2012-09-01

    Full Text Available The Vibrio cholerae lipopolysaccharide O1 antigen is a major target of bacteriophages and the human immune system and is of critical importance for vaccine design. We used an O1-specific lytic bacteriophage as a tool to probe the capacity of V. cholerae to alter its O1 antigen and identified a novel mechanism by which this organism can modulate O antigen expression and exhibit intra-strain heterogeneity. We identified two phase variable genes required for O1 antigen biosynthesis, manA and wbeL. manA resides outside of the previously recognized O1 antigen biosynthetic locus, and encodes for a phosphomannose isomerase critical for the initial step in O1 antigen biosynthesis. We determined that manA and wbeL phase variants are attenuated for virulence, providing functional evidence to further support the critical role of the O1 antigen for infectivity. We provide the first report of phase variation modulating O1 antigen expression in V. cholerae, and show that the maintenance of these phase variable loci is an important means by which this facultative pathogen can generate the diverse subpopulations of cells needed for infecting the host intestinal tract and for escaping predation by an O1-specific phage.

  4. Induction of antitumor immunity through xenoplacental immunization

    Directory of Open Access Journals (Sweden)

    Agadjanyan Michael G

    2006-05-01

    Full Text Available Abstract Historically cancer vaccines have yielded suboptimal clinical results. We have developed a novel strategy for eliciting antitumor immunity based upon homology between neoplastic tissue and the developing placenta. Placenta formation shares several key processes with neoplasia, namely: angiogenesis, activation of matrix metalloproteases, and active suppression of immune function. Immune responses against xenoantigens are well known to break self-tolerance. Utilizing xenogeneic placental protein extracts as a vaccine, we have successfully induced anti-tumor immunity against B16 melanoma in C57/BL6 mice, whereas control xenogeneic extracts and B16 tumor extracts where ineffective, or actually promoted tumor growth, respectively. Furthermore, dendritic cells were able to prime tumor immunity when pulsed with the placental xenoantigens. While vaccination-induced tumor regression was abolished in mice depleted of CD4 T cells, both CD4 and CD8 cells were needed to adoptively transfer immunity to naïve mice. Supporting the role of CD8 cells in controlling tumor growth are findings that only freshly isolated CD8 cells from immunized mice were capable of inducing tumor cell caspases-3 activation ex vivo. These data suggest feasibility of using xenogeneic placental preparations as a multivalent vaccine potently targeting not just tumor antigens, but processes that are essential for tumor maintenance of malignant potential.

  5. 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

  6. Immunization of Mice with Anthrax Protective Antigen Limits Cardiotoxicity but Not Hepatotoxicity Following Lethal Toxin Challenge

    Directory of Open Access Journals (Sweden)

    T. Scott Devera

    2015-06-01

    Full Text Available Protective immunity against anthrax is inferred from measurement of vaccine antigen-specific neutralizing antibody titers in serum samples. In animal models, in vivo challenges with toxin and/or spores can also be performed. However, neither of these approaches considers toxin-induced damage to specific organ systems. It is therefore important to determine to what extent anthrax vaccines and existing or candidate adjuvants can provide organ-specific protection against intoxication. We therefore compared the ability of Alum, CpG DNA and the CD1d ligand α-galactosylceramide (αGC to enhance protective antigen-specific antibody titers, to protect mice against challenge with lethal toxin, and to block cardiotoxicity and hepatotoxicity. By measurement of serum cardiac Troponin I (cTnI, and hepatic alanine aminotransferase (ALT, and aspartate aminotransferase (AST, it was apparent that neither vaccine modality prevented hepatic intoxication, despite high Ab titers and ultimate survival of the subject. In contrast, cardiotoxicity was greatly diminished by prior immunization. This shows that a vaccine that confers survival following toxin exposure may still have an associated morbidity. We propose that organ-specific intoxication should be monitored routinely during research into new vaccine modalities.

  7. Specific recycling receptors are targeted to the immune synapse by the intraflagellar transport system

    Science.gov (United States)

    Finetti, Francesca; Patrussi, Laura; Masi, Giulia; Onnis, Anna; Galgano, Donatella; Lucherini, Orso Maria; Pazour, Gregory J.; Baldari, Cosima T.

    2014-01-01

    ABSTRACT T cell activation requires sustained signaling at the immune synapse, a specialized interface with the antigen-presenting cell (APC) that assembles following T cell antigen receptor (TCR) engagement by major histocompatibility complex (MHC)-bound peptide. Central to sustained signaling is the continuous recruitment of TCRs to the immune synapse. These TCRs are partly mobilized from an endosomal pool by polarized recycling. We have identified IFT20, a component of the intraflagellar transport (IFT) system that controls ciliogenesis, as a central regulator of TCR recycling to the immune synapse. Here, we have investigated the interplay of IFT20 with the Rab GTPase network that controls recycling. We found that IFT20 forms a complex with Rab5 and the TCR on early endosomes. IFT20 knockdown (IFT20KD) resulted in a block in the recycling pathway, leading to a build-up of recycling TCRs in Rab5+ endosomes. Recycling of the transferrin receptor (TfR), but not of CXCR4, was disrupted by IFT20 deficiency. The IFT components IFT52 and IFT57 were found to act together with IFT20 to regulate TCR and TfR recycling. The results provide novel insights into the mechanisms that control TCR recycling and immune synapse assembly, and underscore the trafficking-related function of the IFT system beyond ciliogenesis. PMID:24554435

  8. MERS-CoV and H5N1 influenza virus antagonize antigen presentation by altering the epigenetic landscape

    Energy Technology Data Exchange (ETDEWEB)

    Menachery, Vineet D.; Schafer, Alexandra; Burnum-Johnson, Kristin E.; Mitchell, Hugh D.; Eisfeld-Fenney, Amie J.; Walters, Kevin B.; Nicora, Carrie D.; Purvine, Samuel O.; Casey, Cameron P.; Monroe, Matthew E.; Weitz, Karl K.; Stratton, Kelly G.; Webb-Robertson, Bobbie-Jo M.; Gralinski, Lisa; Metz, Thomas O.; Smith, Richard D.; Waters, Katrina M.; Sims, Amy C.; Kawaoka, Yoshihiro; Baric, Ralph

    2018-01-16

    Convergent evolution dictates that diverse groups of viruses will target both similar and distinct host pathways in order to manipulate the immune response and improve infection. In this study, we sought to leverage this uneven viral antagonism to identify critical host factors that govern disease outcome. Utilizing a systems based approach, we examined differential regulation of IFNγ dependent genes following infection with highly pathogenic viruses including influenza (H5N1-VN1203, H1N1-CA04) and coronaviruses (SARS-CoV, MERS-CoV). Categorizing by function, we observed down regulation of genes associated with antigen presentation following both H5N1-VN1203 and MERS-CoV infection. Further examination revealed global down regulation of antigen presentation genes and was confirmed by proteomics for both H5N1-VN1203 and MERS-CoV infection. Importantly, epigenetic analysis suggested that DNA methylation rather than histone modification plays a crucial role in MERS-CoV mediated antagonism of antigen presentation genes; in contrast, H5N1-VN1203 likely utilizes a combination of epigenetic mechanisms to target antigen presentation. Together, the results indicate a common approach utilized by H5N1-VN1203 and MERS-CoV to modulate antigen presentation and the host adaptive immune response.

  9. Reduction of T-Helper Cell Responses to Recall Antigen Mediated by Codelivery with Peptidoglycan via the Intestinal Nanomineral-Antigen Pathway.

    Science.gov (United States)

    Hewitt, Rachel E; Robertson, Jack; Haas, Carolin T; Pele, Laetitia C; Powell, Jonathan J

    2017-01-01

    Naturally occurring intestinal nanomineral particles constituently form in the mammalian gut and trap luminal protein and microbial components. These cargo loaded nanominerals are actively scavenged by M cells of intestinal immune follicles, such as Peyer's patches and are passed to antigen-presenting cells. Using peripheral blood mononuclear cell populations as an in vitro model of nanomineral uptake and antigen presentation, we show that monocytes avidly phagocytose nanomineral particles bearing antigen and peptidoglycan (PGN), and that the presence of PGN within particles downregulates their cell surface MHC class II and upregulates programmed death receptor ligand 1. Nanomineral delivery of antigen suppresses antigen-specific CD4 + T cell responses, an effect that is enhanced in the presence of PGN. Blocking the interleukin-10 receptor restores CD4 + T cell responses to antigen codelivered with PGN in nanomineral form. Using human intestinal specimens, we have shown that the in vivo nanomineral pathway operates in an interleukin-10 rich environment. Consequently, the delivery of a dual antigen-PGN cargo by endogenous nanomineral in vivo is likely to be important in the establishment of intestinal tolerance, while their synthetic mimetics present a potential delivery system for therapeutic applications targeting the modulation of Peyer's patch T cell responses.

  10. Sensitivity of immune response quality to influenza helix 190 antigen structure displayed on a modular virus-like particle.

    Science.gov (United States)

    Anggraeni, Melisa R; Connors, Natalie K; Wu, Yang; Chuan, Yap P; Lua, Linda H L; Middelberg, Anton P J

    2013-09-13

    Biomolecular engineering enables synthesis of improved proteins through synergistic fusion of modules from unrelated biomolecules. Modularization of peptide antigen from an unrelated pathogen for presentation on a modular virus-like particle (VLP) represents a new and promising approach to synthesize safe and efficacious vaccines. Addressing a key knowledge gap in modular VLP engineering, this study investigates the underlying fundamentals affecting the ability of induced antibodies to recognize the native pathogen. Specifically, this quality of immune response is correlated to the peptide antigen module structure. We modularized a helical peptide antigen element, helix 190 (H190) from the influenza hemagglutinin (HA) receptor binding region, for presentation on murine polyomavirus VLP, using two strategies aimed to promote H190 helicity on the VLP. In the first strategy, H190 was flanked by GCN4 structure-promoting elements within the antigen module; in the second, dual H190 copies were arrayed as tandem repeats in the module. Molecular dynamics simulation predicted that tandem repeat arraying would minimize secondary structural deviation of modularized H190 from its native conformation. In vivo testing supported this finding, showing that although both modularization strategies conferred high H190-specific immunogenicity, tandem repeat arraying of H190 led to a strikingly higher immune response quality, as measured by ability to generate antibodies recognizing a recombinant HA domain and split influenza virion. These findings provide new insights into the rational engineering of VLP vaccines, and could ultimately enable safe and efficacious vaccine design as an alternative to conventional approaches necessitating pathogen cultivation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Alphavirus Replicon DNA Vectors Expressing Ebola GP and VP40 Antigens Induce Humoral and Cellular Immune Responses in Mice

    Directory of Open Access Journals (Sweden)

    Shoufeng Ren

    2018-01-01

    Full Text Available Ebola virus (EBOV causes severe hemorrhagic fevers in humans, and no approved therapeutics or vaccine is currently available. Glycoprotein (GP is the major protective antigen of EBOV, and can generate virus-like particles (VLPs by co-expression with matrix protein (VP40. In this study, we constructed a recombinant Alphavirus Semliki Forest virus (SFV replicon vector DREP to express EBOV GP and matrix viral protein (VP40. EBOV VLPs were successfully generated and achieved budding from 293 cells after co-transfection with DREP-based GP and VP40 vectors (DREP-GP+DREP-VP40. Vaccination of BALB/c mice with DREP-GP, DREP-VP40, or DREP-GP+DREP-VP40 vectors, followed by immediate electroporation resulted in a mixed IgG subclass production, which recognized EBOV GP and/or VP40 proteins. This vaccination regimen also led to the generation of both Th1 and Th2 cellular immune responses in mice. Notably, vaccination with DREP-GP and DREP-VP40, which produces both GP and VP40 antigens, induced a significantly higher level of anti-GP IgG2a antibody and increased IFN-γ secreting CD8+ T-cell responses relative to vaccination with DREP-GP or DREP-VP40 vector alone. Our study indicates that co-expression of GP and VP40 antigens based on the SFV replicon vector generates EBOV VLPs in vitro, and vaccination with recombinant DREP vectors containing GP and VP40 antigens induces Ebola antigen-specific humoral and cellular immune responses in mice. This novel approach provides a simple and efficient vaccine platform for Ebola disease prevention.

  12. Design of a novel integration-deficient lentivector technology that incorporates genetic and posttranslational elements to target human dendritic cells.

    Science.gov (United States)

    Tareen, Semih U; Kelley-Clarke, Brenna; Nicolai, Christopher J; Cassiano, Linda A; Nelson, Lisa T; Slough, Megan M; Vin, Chintan D; Odegard, Jared M; Sloan, Derek D; Van Hoeven, Neal; Allen, James M; Dubensky, Thomas W; Robbins, Scott H

    2014-03-01

    As sentinels of the immune system, dendritic cells (DCs) play an essential role in regulating cellular immune responses. One of the main challenges of developing DC-targeted therapies includes the delivery of antigen to DCs in order to promote the activation of antigen-specific effector CD8 T cells. With the goal of creating antigen-directed immunotherapeutics that can be safely administered directly to patients, Immune Design has developed a platform of novel integration-deficient lentiviral vectors that target and deliver antigen-encoding nucleic acids to human DCs. This platform, termed ID-VP02, utilizes a novel genetic variant of a Sindbis virus envelope glycoprotein with posttranslational carbohydrate modifications in combination with Vpx, a SIVmac viral accessory protein, to achieve efficient targeting and transduction of human DCs. In addition, ID-VP02 incorporates safety features in its design that include two redundant mechanisms to render ID-VP02 integration-deficient. Here, we describe the characteristics that allow ID-VP02 to specifically transduce human DCs, and the advances that ID-VP02 brings to conventional third-generation lentiviral vector design as well as demonstrate upstream production yields that will enable manufacturing feasibility studies to be conducted.

  13. antigen from irradiated Trypanosoma evansi and its correlation with antibody forming

    International Nuclear Information System (INIS)

    Sadi, Suharni; Arifin, Muchson

    1998-01-01

    In this research parasites of T. evansi was weakened by gamma irradiation dose of 300 Gy. This antigen being before being used was coupled/bounded with a carrier (Freund's adjuvant). West star rats of 3 months old were as used as treated animal. These animal were divided into 4 groups contained 5 rats. Group I (Control) was untreated animals, Group II (radiation) the animals were irradiated with a low dose 0.5 Gy. Group III Immunization) the animals were immunized with irradiated antigen, and Group IV (Immunization and radiation) the animal were immunized and then irradiated with a low dose of 0.5 Gy. Immunization were done by intraperitoneal route with irradiated antigen (0.5-1ml). These results were as follows : the polyclonal antibody forming of Group I (control), Group II (Radiation), Group III (Immunization), and Group IV (Immunization and radiation) were 6.34; 5.96; and 5.88 mg/ml, respectively. Group III (Immunization) Yielded polyclonal antibody a little higher than the other treated animals. Even though the antigen was coupled with a carrier, it seemed that it did not influence the parasites variant antigenic types (VTA). (author)

  14. Effect of antigen shedding on targeted delivery of immunotoxins in solid tumors from a mathematical model.

    Directory of Open Access Journals (Sweden)

    Youngshang Pak

    Full Text Available Most cancer-specific antigens used as targets of antibody-drug conjugates and immunotoxins are shed from the cell surface (Zhang & Pastan (2008 Clin. Cancer Res. 14: 7981-7986, although at widely varying rates and by different mechanisms (Dello Sbarba & Rovida (2002 Biol. Chem. 383: 69-83. Why many cancer-specific antigens are shed and how the shedding affects delivery efficiency of antibody-based protein drugs are poorly understood questions at present. Before a detailed numerical study, it was assumed that antigen shedding would reduce the efficacy of antibody-drug conjugates and immunotoxins. However, our previous study using a comprehensive mathematical model showed that antigen shedding can significantly improve the efficacy of the mesothelin-binding immunotoxin, SS1P (anti-mesothelin-Fv-PE38, and suggested that receptor shedding can be a general mechanism for enhancing the effect of inter-cellular signaling molecules. Here, we improved this model and applied it to both SS1P and another recombinant immunotoxin, LMB-2, which targets CD25. We show that the effect of antigen shedding is influenced by a number of factors including the number of antigen molecules on the cell surface and the endocytosis rate. The high shedding rate of mesothelin is beneficial for SS1P, for which the antigen is large in number and endocytosed rapidly. On the other hand, the slow shedding of CD25 is beneficial for LMB-2, for which the antigen is small in number and endocytosed slowly.

  15. Mechanism of immune evasion in breast cancer

    Science.gov (United States)

    Wang, Mozhi; Zhang, Changwang; Song, Yongxi; Wang, Zhenning; Wang, Yaojia; Luo, Fang; Xu, Yujie; Zhao, Yi; Wu, Zhonghua; Xu, Yingying

    2017-01-01

    Breast cancer (BC) is the most common malignant tumor among women, with high morbidity and mortality. Its onset, development, metastasis, and prognosis vary among individuals due to the interactions between tumors and host immunity. Many diverse mechanisms have been associated with BC, with immune evasion being the most widely studied to date. Tumor cells can escape from the body’s immune response, which targets abnormal components and foreign bodies, using different approaches including modification of surface antigens and modulation of the surrounding environment. In this review, we summarize the mechanisms and factors that impact the immunoediting process and analyze their functions in detail. PMID:28352189

  16. Humoral immune responses of dengue fever patients using epitope-specific serotype-2 virus-like particle antigens.

    Directory of Open Access Journals (Sweden)

    Wayne D Crill

    Full Text Available Dengue virus (DENV is a serious mosquito-borne pathogen causing significant global disease burden, either as classic dengue fever (DF or in its most severe manifestation dengue hemorrhagic fever (DHF. Nearly half of the world's population is at risk of dengue disease and there are estimated to be millions of infections annually; a situation which will continue to worsen with increasing expansion of the mosquito vectors and epidemic DF/DHF. Currently there are no available licensed vaccines or antivirals for dengue, although significant effort has been directed toward the development of safe and efficacious dengue vaccines for over 30 years. Promising vaccine candidates are in development and testing phases, but a better understanding of immune responses to DENV infection and vaccination is needed. Humoral immune responses to DENV infection are complex and may exacerbate pathogenicity, yet are essential for immune protection. In this report, we develop DENV-2 envelope (E protein epitope-specific antigens and measure immunoglobulin responses to three distinct epitopes in DENV-2 infected human serum samples. Immunoglobulin responses to DENV-2 infection exhibited significant levels of individual variation. Antibody populations targeting broadly cross-reactive epitopes centered on the fusion peptide in structural domain II were large, highly variable, and greater in primary than in secondary DENV-2 infected sera. E protein domain III cross-reactive immunoglobulin populations were similarly variable and much larger in IgM than in IgG. DENV-2 specific domain III IgG formed a very small proportion of the antibody response yet was significantly correlated with DENV-2 neutralization, suggesting that the highly protective IgG recognizing this epitope in murine studies plays a role in humans as well. This report begins to tease apart complex humoral immune responses to DENV infection and is thus important for improving our understanding of dengue disease

  17. 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

  18. A prospective study of the influence of a thalassaemia on morbidity from malaria and immune responses to defined Plasmodium falciparum antigens in Gambian children

    DEFF Research Database (Denmark)

    Allen, S J; Rowe, P; Allsopp, C E

    1993-01-01

    with the sickle cell trait alone. Specific antibody responses and cell-mediated immune responses in vitro to defined Plasmodium falciparum antigens were measured in children participating in the study. In general, there was no evidence of an increased prevalence or intensity of humoral or cell-mediated immune...

  19. Plasma membrane associated, virus-specific polypeptides required for the formation of target antigen complexes recognized by virus-specific cytotoxic T lymphocytes

    International Nuclear Information System (INIS)

    Domber, E.A.

    1986-01-01

    These studies were undertaken to define some of the poxvirus-specific target antigens which are synthesized in infected cells and recognized by vaccinia virus-specific CTLs (VV-CTLs). Since vaccinia virus infected, unmanipulated target cells express numerous virus-specific antigens on the plasma membrane, attempts were made to manipulate expression of the poxvirus genome after infection so that one or a few defined virus-specified antigens were expressed on the surface of infected cells. In vitro [ 51 Cr]-release assays determined that viral DNA synthesis and expression of late viral proteins were not necessary to form a target cell which was fully competent for lysis by VV-CTLs. Under the conditions employed in these experiments, 90-120 minutes of viral protein synthesis were necessary to produce a competent cell for lysis by VV-CTLs. In order to further inhibit the expression of early viral proteins in infected cells, partially UV-inactivated vaccinia virus was employed to infect target cells. It was determined that L-cells infected with virus preparations which had been UV-irradiated for 90 seconds were fully competent for lysis by VV-CTLs. Cells infected with 90 second UV-irr virus expressed 3 predominant, plasma membrane associated antigens of 36-37K, 27-28K, and 19-17K. These 3 viral antigens represent the predominant membrane-associated viral antigens available for interaction with class I, major histocompatibility antigens and hence are potential target antigens for VV-CTLs

  20. Geographical and temporal conservation of antibody recognition of Plasmodium falciparum variant surface antigens

    DEFF Research Database (Denmark)

    Nielsen, Morten A; Vestergaard, Lasse S; Lusingu, John

    2004-01-01

    The slow acquisition of protection against Plasmodium falciparum malaria probably reflects the extensive diversity of important antigens. The variant surface antigens (VSA) that mediate parasite adhesion to a range of host molecules are regarded as important targets of acquired protective immunity......, but their diversity makes them questionable vaccine candidates. We determined levels of VSA-specific immunoglobulin G (IgG) in human plasma collected at four geographically distant and epidemiologically distinct localities with specificity for VSA expressed by P. falciparum isolates from three African countries...

  1. Molecular mechanism and function of CD40/CD40L engagement in the immune system.

    Science.gov (United States)

    Elgueta, Raul; Benson, Micah J; de Vries, Victor C; Wasiuk, Anna; Guo, Yanxia; Noelle, Randolph J

    2009-05-01

    During the generation of a successful adaptive immune response, multiple molecular signals are required. A primary signal is the binding of cognate antigen to an antigen receptor expressed by T and B lymphocytes. Multiple secondary signals involve the engagement of costimulatory molecules expressed by T and B lymphocytes with their respective ligands. Because of its essential role in immunity, one of the best characterized of the costimulatory molecules is the receptor CD40. This receptor, a member of the tumor necrosis factor receptor family, is expressed by B cells, professional antigen-presenting cells, as well as non-immune cells and tumors. CD40 binds its ligand CD40L, which is transiently expressed on T cells and other non-immune cells under inflammatory conditions. A wide spectrum of molecular and cellular processes is regulated by CD40 engagement including the initiation and progression of cellular and humoral adaptive immunity. In this review, we describe the downstream signaling pathways initiated by CD40 and overview how CD40 engagement or antagonism modulates humoral and cellular immunity. Lastly, we discuss the role of CD40 as a target in harnessing anti-tumor immunity. This review underscores the essential role CD40 plays in adaptive immunity.

  2. Ovarian cancer and the immune system - The role of targeted therapies.

    Science.gov (United States)

    Turner, Taylor B; Buchsbaum, Donald J; Straughn, J Michael; Randall, Troy D; Arend, Rebecca C

    2016-08-01

    The majority of patients with epithelial ovarian cancer are diagnosed with advanced disease. While many of these patients will respond initially to chemotherapy, the majority will relapse and die of their disease. Targeted therapies that block or activate specific intracellular signaling pathways have been disappointing. In the past 15years, the role of the immune system in ovarian cancer has been investigated. Patients with a more robust immune response, as documented by the presence of lymphocytes infiltrating within their tumor, have increased survival and better response to chemotherapy. In addition, a strong immunosuppressive environment often accompanies ovarian cancer. Recent research has identified potential therapies that leverage the immune system to identify and destroy tumor cells that previously evaded immunosurveillance mechanisms. In this review, we discuss the role of the immune system in ovarian cancer and focus on specific pathways and molecules that show a potential for targeted therapy. We also review the ongoing clinical trials using targeted immunotherapy in ovarian cancer. The role of targeted immunotherapy in patients with ovarian cancer represents a field of growing research and clinical importance. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. 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.,).

  4. 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.,).

  5. 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.

  6. Presentation of lipid antigens to T cells.

    Science.gov (United States)

    Mori, Lucia; De Libero, Gennaro

    2008-04-15

    T cells specific for lipid antigens participate in regulation of the immune response during infections, tumor immunosurveillance, allergy and autoimmune diseases. T cells recognize lipid antigens as complexes formed with CD1 antigen-presenting molecules, thus resembling recognition of MHC-peptide complexes. The biophysical properties of lipids impose unique mechanisms for their delivery, internalization into antigen-presenting cells, membrane trafficking, processing, and loading of CD1 molecules. Each of these steps is controlled at molecular and celular levels and determines lipid immunogenicity. Lipid antigens may derive from microbes and from the cellular metabolism, thus allowing the immune system to survey a large repertoire of immunogenic molecules. Recognition of lipid antigens facilitates the detection of infectious agents and the initiation of responses involved in immunoregulation and autoimmunity. This review focuses on the presentation mechanisms and specific recognition of self and bacterial lipid antigens and discusses the important open issues.

  7. Original antigenic sin responses to influenza viruses.

    Science.gov (United States)

    Kim, Jin Hyang; Skountzou, Ioanna; Compans, Richard; Jacob, Joshy

    2009-09-01

    Most immune responses follow Burnet's rule in that Ag recruits specific lymphocytes from a large repertoire and induces them to proliferate and differentiate into effector cells. However, the phenomenon of "original antigenic sin" stands out as a paradox to Burnet's rule of B cell engagement. Humans, upon infection with a novel influenza strain, produce Abs against older viral strains at the expense of responses to novel, protective antigenic determinants. This exacerbates the severity of the current infection. This blind spot of the immune system and the redirection of responses to the "original Ag" rather than to novel epitopes were described fifty years ago. Recent reports have questioned the existence of this phenomenon. Hence, we revisited this issue to determine the extent to which original antigenic sin is induced by variant influenza viruses. Using two related strains of influenza A virus, we show that original antigenic sin leads to a significant decrease in development of protective immunity and recall responses to the second virus. In addition, we show that sequential infection of mice with two live influenza virus strains leads to almost exclusive Ab responses to the first viral strain, suggesting that original antigenic sin could be a potential strategy by which variant influenza viruses subvert the immune system.

  8. 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

  9. Prophylactic Sublingual Immunization with Mycobacterium tuberculosis Subunit Vaccine Incorporating the Natural Killer T Cell Agonist Alpha-Galactosylceramide Enhances Protective Immunity to Limit Pulmonary and Extra-Pulmonary Bacterial Burden in Mice

    Directory of Open Access Journals (Sweden)

    Arshad Khan

    2017-12-01

    Full Text Available Infection by Mycobacterium tuberculosis (Mtb remains a major global concern and the available Bacillus Calmette-Guerin (BCG vaccine is poorly efficacious in adults. Therefore, alternative vaccines and delivery strategies focusing on Mtb antigens and appropriate immune stimulating adjuvants are needed to induce protective immunity targeted to the lungs, the primary sites of infections and pathology. We present here evidence in support of mucosal vaccination by the sublingual route in mice using the subunit Mtb antigens Ag85B and ESAT-6 adjuvanted with the glycolipid alpha-galactosylceramide (α-GalCer, a potent natural killer T (NKT cell agonist. Vaccinated animals exhibited strong antigen-specific CD4 and CD8 T cells responses in the spleen, cervical lymph nodes and lungs. In general, inclusion of the α-GalCer adjuvant significantly enhanced these responses that persisted over 50 days. Furthermore, aerosolized Mtb infection of vaccinated mice resulted in a significant reduction of bacterial load of the lungs and spleens as compared to levels seen in naïve controls or those vaccinated with subunit proteins, adjuvant , or BCG alone. The protection induced by the Mtb antigens and-GalCer vaccine through sublingual route correlated with a TH1-type immunity mediated by antigen-specific IFN-γ and IL-2 producing T cells.

  10. Newly Emerging Immune Checkpoints: Promises for Future Cancer Therapy

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    Robert J. Torphy

    2017-12-01

    Full Text Available Cancer immunotherapy has been a great breakthrough, with immune checkpoint inhibitors leading the way. Despite the clinical effectiveness of certain immune checkpoint inhibitors, the overall response rate remains low, and the effectiveness of immunotherapies for many tumors has been disappointing. There is substantial interest in looking for additional immune checkpoint molecules that may act as therapeutic targets for cancer. Recent advances during the last decade have identified several novel immune checkpoint targets, including lymphocyte activation gene-3 (LAG-3, B and T lymphocyte attenuator (BTLA, programmed death-1 homolog (PD-1H, T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIM-3/carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1, and the poliovirus receptor (PVR-like receptors. The investigations into these molecules have generated promising results in preclinical studies. Herein, we will summarize our current progress and understanding of these newly-characterized immune checkpoints and their potential application in cancer immunotherapy.

  11. Reduction of T-Helper Cell Responses to Recall Antigen Mediated by Codelivery with Peptidoglycan via the Intestinal Nanomineral–Antigen Pathway

    Science.gov (United States)

    Hewitt, Rachel E.; Robertson, Jack; Haas, Carolin T.; Pele, Laetitia C.; Powell, Jonathan J.

    2017-01-01

    Naturally occurring intestinal nanomineral particles constituently form in the mammalian gut and trap luminal protein and microbial components. These cargo loaded nanominerals are actively scavenged by M cells of intestinal immune follicles, such as Peyer’s patches and are passed to antigen-presenting cells. Using peripheral blood mononuclear cell populations as an in vitro model of nanomineral uptake and antigen presentation, we show that monocytes avidly phagocytose nanomineral particles bearing antigen and peptidoglycan (PGN), and that the presence of PGN within particles downregulates their cell surface MHC class II and upregulates programmed death receptor ligand 1. Nanomineral delivery of antigen suppresses antigen-specific CD4+ T cell responses, an effect that is enhanced in the presence of PGN. Blocking the interleukin-10 receptor restores CD4+ T cell responses to antigen codelivered with PGN in nanomineral form. Using human intestinal specimens, we have shown that the in vivo nanomineral pathway operates in an interleukin-10 rich environment. Consequently, the delivery of a dual antigen–PGN cargo by endogenous nanomineral in vivo is likely to be important in the establishment of intestinal tolerance, while their synthetic mimetics present a potential delivery system for therapeutic applications targeting the modulation of Peyer’s patch T cell responses. PMID:28367148

  12. rBCG30-induced immunity and cross-protection against Mycobacterium leprae challenge are enhanced by boosting with the Mycobacterium tuberculosis 30-kilodalton antigen 85B.

    Science.gov (United States)

    Gillis, Thomas P; Tullius, Michael V; Horwitz, Marcus A

    2014-09-01

    Leprosy remains a major global health problem and typically occurs in regions in which tuberculosis is endemic. Vaccines are needed that protect against both infections and do so better than the suboptimal Mycobacterium bovis BCG vaccine. Here, we evaluated rBCG30, a vaccine previously demonstrated to induce protection superior to that of BCG against Mycobacterium tuberculosis and Mycobacterium bovis challenge in animal models, for efficacy against Mycobacterium leprae challenge in a murine model of leprosy. rBCG30 overexpresses the M. tuberculosis 30-kDa major secretory protein antigen 85B, which is 85% homologous with the M. leprae homolog (r30ML). Mice were sham immunized or immunized intradermally with BCG or rBCG30 and challenged 2.5 months later by injection of viable M. leprae into each hind footpad. After 7 months, vaccine efficacy was assessed by enumerating the M. leprae bacteria per footpad. Both BCG and rBCG30 induced significant protection against M. leprae challenge. In the one experiment in which a comparison between BCG and rBCG30 was feasible, rBCG30 induced significantly greater protection than did BCG. Immunization of mice with purified M. tuberculosis or M. leprae antigen 85B also induced protection against M. leprae challenge but less so than BCG or rBCG30. Notably, boosting rBCG30 with M. tuberculosis antigen 85B significantly enhanced r30ML-specific immune responses, substantially more so than boosting BCG, and significantly augmented protection against M. leprae challenge. Thus, rBCG30, a vaccine that induces improved protection against M. tuberculosis, induces cross-protection against M. leprae that is comparable or potentially superior to that induced by BCG, and boosting rBCG30 with antigen 85B further enhances immune responses and protective efficacy. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  13. Immune responses to baculovirus-displayed enterovirus 71 VP1 antigen.

    Science.gov (United States)

    Kiener, Tanja K; Premanand, Balraj; Kwang, Jimmy

    2013-04-01

    The increased distribution and neurovirulence of enterovirus 71 is an important health threat for young children in Asia Pacific. Vaccine design has concentrated on inactivated virus with the most advanced undergoing Phase III clinical trials. By using a subunit vaccine approach, production costs could be reduced by lowering the need for biocontainment. In addition, novel mutations could be rapidly incorporated to reflect the emergence of new enterovirus 71 subgenogroups. To circumvent the problems associated with conventional subunit vaccines, the antigen can be displayed on a viral vector that conveys stability and facilitates purification. Additional advantages of viral-vectored subunit vaccines are their ability to stimulate the innate immune system by transducing cells and the possibility of oral or nasal delivery, which dispenses with the need for syringes and medical personnel. Baculovirus-displayed VP1 combines all these benefits with protection that is as efficient as inactivated virus.

  14. Deciphering dendritic cell heterogenity in immunity

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    Michaël eChopin

    2012-02-01

    Full Text Available Dendritic cells (DCs are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These finding open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle – identification of similar DC populations in mouse and man – now set the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  15. Protective effect of intranasal immunization with Neospora caninum membrane antigens against murine neosporosis established through the gastrointestinal tract

    Science.gov (United States)

    Ferreirinha, Pedro; Dias, Joana; Correia, Alexandra; Pérez-Cabezas, Begoña; Santos, Carlos; Teixeira, Luzia; Ribeiro, Adília; Rocha, António; Vilanova, Manuel

    2014-01-01

    Neospora caninum is an Apicomplexa parasite that in the last two decades was acknowledged as the main pathogenic agent responsible for economic losses in the cattle industry. In the present study, the effectiveness of intranasal immunization with N. caninum membrane antigens plus CpG adjuvant was assessed in a murine model of intragastrically established neosporosis. Immunized mice presented a lower parasitic burden in the brain on infection with 5 × 107 tachyzoites, showing that significant protection was achieved by this immunization strategy. Intestinal IgA antibodies raised by immunization markedly agglutinated live N. caninum tachyzoites whereas previous opsonization with IgG antibodies purified from immunized mice sera reduced parasite survival within macrophage cells. Although an IgG1 : IgG2a ratio < 1 was detected in the immunized mice before and after infection, indicative of a predominant T helper type 1 immune response, no increased production of interferon-γ was detected in the spleen or mesenteric lymph nodes of the immunized mice. Altogether, these results show that mucosal immunization with N. caninum membrane proteins plus CpG adjuvant protect against intragastrically established neosporosis and indicate that parasite-specific mucosal and circulating antibodies have a protective role against this parasitic infection. PMID:24128071

  16. Enhanced Dendritic Cell-Mediated Antigen-Specific CD4+ T Cell Responses: IFN-Gamma Aids TLR Stimulation

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    Kuo-Ching Sheng

    2013-01-01

    Full Text Available Phenotypic maturation and T cell stimulation are two functional attributes of DCs critical for immune induction. The combination of antigens, including those from cancer, with Toll-like receptor (TLR ligands induces far superior cellular immune responses compared to antigen alone. In this study, IFN-gamma treatment of bone marrow-derived DC, followed by incubation with the TLR2, TLR4, or TLR9 agonists, enhanced DC activation compared to TLR ligation alone. Most notably, the upregulation of CD40 with LPS stimulation and CD86 with CpG stimulation was observed in in vitro cultures. Similarly, IFN-gamma coinjected with TLR ligands was able to promote DC activation in vivo, with DCs migrating from the site of immunization to the popliteal lymph nodes demonstrating increased expression of CD80 and CD86. The heightened DC activation translated to a drastic increase in T cell stimulatory capacity in both antigen independent and antigen dependent fashions. This is the first time that IFN-gamma has been shown to have a combined effect with TLR ligation to enhance DC activation and function. The results demonstrate the novel use of IFN-gamma together with TLR agonists to enhance antigen-specific T cell responses, for applications in the development of enhanced vaccines and drug targets against diseases including cancer.

  17. Sensitivity and specificity of tritiated thymidine incorporation and ELISPOT assays in identifying antigen specific T cell immune responses

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    MacLeod Beth

    2007-09-01

    Full Text Available Abstract Background Standardization of cell-based immunologic monitoring is becoming increasingly important as methods for measuring cellular immunity become more complex. We assessed the ability of two commonly used cell-based assays, tritiated thymidine incorporation (proliferation and IFN-gamma ELISPOT, to predict T cell responses to HER-2/neu, tetanus toxoid (tt, and cytomegalovirus (CMV antigens. These antigens were determined to be low (HER-2/neu, moderate (tt, and robustly (CMV immunogenic proteins. Samples from 27 Stage II, III, and IV HER-2/neu positive breast cancer patients, vaccinated against the HER-2/neu protein and tt, were analyzed by tritiated thymidine incorporation and IFN-gamma ELISPOT for T cell response. Results Linear regression analysis indicates that both stimulation index (SI (p = 0.011 and IFN-gamma secreting precursor frequency (p Conclusion These data underscore the importance of taking into consideration the performance characteristics of assays used to measure T cell immunity. This consideration is particularly necessary when determining which method to utilize for assessing responses to immunotherapeutic manipulations in cancer patients.

  18. Immune TB Antibody Phage Display Library as a Tool To Study B Cell Immunity in TB Infections.

    Science.gov (United States)

    Hamidon, Nurul Hamizah; Suraiya, Siti; Sarmiento, Maria E; Acosta, Armando; Norazmi, Mohd Nor; Lim, Theam Soon

    2018-03-01

    B cells and in particular antibodies has always played second fiddle to cellular immunity in regard to tuberculosis (TB). However, recent studies has helped position humoral immunity especially antibodies back into the foray in relation to TB immunity. Therefore, the ability to correlate the natural antibody responses of infected individuals toward TB antigens would help strengthen this concept. Phage display is an intriguing approach that can be utilized to study antibody-mediated responses against a particular infection via harvesting the B cell repertoire from infected individuals. The development of disease-specific antibody libraries or immune libraries is useful to better understand antibody-mediated immune responses against specific disease antigens. This study describes the generation of an immune single-chain variable fragment (scFv) library derived from TB-infected individuals. The immune library with an estimated diversity of 10 9 independent clones was then applied for the identification of monoclonal antibodies against Mycobacterium tuberculosis α-crystalline as a model antigen. Biopanning of the library isolated three monoclonal antibodies with unique gene usage. This strengthens the role of antibodies in TB immunity in addition to the role played by cellular immunity. The developed library can be applied against other TB antigens and aid antibody-derived TB immunity studies in the future.

  19. Adaptive immunity to leukemia is inhibited by cross-reactive induced regulatory T cells

    OpenAIRE

    Manlove, Luke S.; Berquam-Vrieze, Katherine E.; Pauken, Kristen E.; Williams, Richard T.; Jenkins, Marc K.; Farrar, Michael A.

    2015-01-01

    BCR-ABL+ acute lymphoblastic leukemia patients have transient responses to current therapies. However, the fusion of BCR to ABL generates a potential leukemia-specific antigen that could be a target for immunotherapy. We demonstrate that the immune system can limit BCR-ABL+ leukemia progression although ultimately this immune response fails. To address how BCR-ABL+ leukemia escapes immune surveillance, we developed a peptide: MHC-II tetramer that labels endogenous BCR-ABL-specific CD4+ T cell...

  20. Structural and Antigenic Definition of Hepatitis C Virus E2 Glycoprotein Epitopes Targeted by Monoclonal Antibodies

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    Giuseppe Sautto

    2013-01-01

    Full Text Available Hepatitis C virus (HCV is the major cause of chronic liver disease as well as the major indication for liver transplantation worldwide. Current standard of care is not completely effective, not administrable in grafted patients, and burdened by several side effects. This incomplete effectiveness is mainly due to the high propensity of the virus to continually mutate under the selective pressure exerted by the host immune response as well as currently administered antiviral drugs. The E2 envelope surface glycoprotein of HCV (HCV/E2 is the main target of the host humoral immune response and for this reason one of the major variable viral proteins. However, broadly cross-neutralizing monoclonal antibodies (mAbs directed against HCV/E2 represent a promising tool for the study of virus-host interplay as well as for the development of effective prophylactic and therapeutic approaches. In the last few years many anti-HCV/E2 mAbs have been evaluated in preclinical and clinical trials as possible candidate antivirals, particularly for administration in pre- and post-transplant settings. In this review we summarize the antigenic and structural characteristics of HCV/E2 determined through the use of anti-HCV/E2 mAbs, which, given the absence of a crystal structure of this glycoprotein, represent currently the best tool available.

  1. C-type lectins: their network and roles in pathogen recognition and immunity.

    Science.gov (United States)

    Mayer, Sabine; Raulf, Marie-Kristin; Lepenies, Bernd

    2017-02-01

    C-type lectins (CTLs) represent the most complex family of animal/human lectins that comprises 17 different groups. During evolution, CTLs have developed by diversification to cover a broad range of glycan ligands. However, ligand binding by CTLs is not necessarily restricted to glycans as some CTLs also bind to proteins, lipids, inorganic molecules, or ice crystals. CTLs share a common fold that harbors a Ca 2+ for contact to the sugar and about 18 invariant residues in a phylogenetically conserved pattern. In vertebrates, CTLs have numerous functions, including serum glycoprotein homeostasis, pathogen sensing, and the initiation of immune responses. Myeloid CTLs in innate immunity are mainly expressed by antigen-presenting cells and play a prominent role in the recognition of a variety of pathogens such as fungi, bacteria, viruses, and parasites. However, myeloid CTLs such as the macrophage inducible CTL (Mincle) or Clec-9a may also bind to self-antigens and thus contribute to immune homeostasis. While some CTLs induce pro-inflammatory responses and thereby lead to activation of adaptive immune responses, other CTLs act as inhibitory receptors and dampen cellular functions. Since CTLs are key players in pathogen recognition and innate immunity, targeting CTLs may be a promising strategy for cell-specific delivery of drugs or vaccine antigens and to modulate immune responses.

  2. Incorporation of Immune Checkpoint Blockade into Chimeric Antigen Receptor T Cells (CAR-Ts): Combination or Built-In CAR-T.

    Science.gov (United States)

    Yoon, Dok Hyun; Osborn, Mark J; Tolar, Jakub; Kim, Chong Jai

    2018-01-24

    Chimeric antigen receptor (CAR) T cell therapy represents the first U.S. Food and Drug Administration approved gene therapy and these engineered cells function with unprecedented efficacy in the treatment of refractory CD19 positive hematologic malignancies. CAR translation to solid tumors is also being actively investigated; however, efficacy to date has been variable due to tumor-evolved mechanisms that inhibit local immune cell activity. To bolster the potency of CAR-T cells, modulation of the immunosuppressive tumor microenvironment with immune-checkpoint blockade is a promising strategy. The impact of this approach on hematological malignancies is in its infancy, and in this review we discuss CAR-T cells and their synergy with immune-checkpoint blockade.

  3. Incorporation of Immune Checkpoint Blockade into Chimeric Antigen Receptor T Cells (CAR-Ts: Combination or Built-In CAR-T

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    Dok Hyun Yoon

    2018-01-01

    Full Text Available Chimeric antigen receptor (CAR T cell therapy represents the first U.S. Food and Drug Administration approved gene therapy and these engineered cells function with unprecedented efficacy in the treatment of refractory CD19 positive hematologic malignancies. CAR translation to solid tumors is also being actively investigated; however, efficacy to date has been variable due to tumor-evolved mechanisms that inhibit local immune cell activity. To bolster the potency of CAR-T cells, modulation of the immunosuppressive tumor microenvironment with immune-checkpoint blockade is a promising strategy. The impact of this approach on hematological malignancies is in its infancy, and in this review we discuss CAR-T cells and their synergy with immune-checkpoint blockade.

  4. MYCN: from oncoprotein to tumor-associated antigen

    International Nuclear Information System (INIS)

    Pistoia, Vito; Morandi, Fabio; Pezzolo, Annalisa; Raffaghello, Lizzia; Prigione, Ignazia

    2012-01-01

    MYCN is a well-known oncogene over-expressed in different human malignancies including neuroblastoma (NB), rhabdomyosarcoma, medulloblastoma, astrocytoma, Wilms’ tumor, and small cell lung cancer. In the case of NB, MYCN amplification is an established biomarker of poor-prognosis. MYCN belongs to a family of transcription factors (the most important of which is C-MYC) that show a high degree of homology. Down-regulation of MYC protein expression leads to tumor regression in animal models, indicating that MYC proteins represent interesting therapeutic targets. Pre-requisites for a candidate tumor-associated antigen (TAA) to be targeted by immunotherapeutic approaches are the following, (i) expression should be tumor-restricted, (ii) the putative TAA should be up-regulated in cancer cells, and (iii) protein should be processed into immunogenic peptides capable of associating to major histocompatibility complex molecules with high affinity. Indeed, the MYCN protein is not expressed in human adult tissues and up-regulated variably in NB cells, and MYCN peptides capable of associating to HLA-A1 or HLA-A2 molecules with high affinity have been identified. Thus the MYCN protein qualifies as putative TAA in NB. Additional issues that determine the feasibility of targeting a putative TAA with cytotoxic T lymphocytes (CTLs) and will be here discussed are the following, (i) the inadequacy of tumor cells per se to act as antigen-presenting cells witnessed, in the case of NB cells, by the low to absent expression of HLA class I molecules, the lack of co-stimulatory molecules and multiple defects in the HLA class I related antigen processing machinery, and (ii) the immune evasion mechanisms operated by cancer cells to fool the host immune system, such as up-regulation of soluble immunosuppressive molecules (e.g., soluble MICA and HLA-G in the case of NB) or generation of immunosuppressive cells in the tumor microenvironment. A final issue that deserves consideration is the

  5. MYCN: From Oncoprotein To Tumor-Associated Antigen

    Directory of Open Access Journals (Sweden)

    Vito ePistoia

    2012-11-01

    Full Text Available MYCN is a well known oncogene overexpressed in different human malignancies including neuroblastoma, rhabdomyosarcoma, medulloblastoma, astrocytoma, Wilms’ tumor and small cell lung cancer. In the case of neuroblastoma (NB, MYCN amplification is an established biomarker of poor prognosis. MYCN belongs to a family of transcription factors (the most important of which is CMYC that show a high degree of homology. Downregulation of MYC protein expression leads to tumor regression in animal models, indicating that MYC proteins represent interesting therapeutic targets.Pre-requisites for a candidate tumor-associated antigen (TAA to be targeted by immunotherapeutic approaches are the following, i expression should be tumor-restricted, ii the putative TAA should be up-regulated in cancer cells and iii protein should be processed into immunogenic peptides capable of associating to MHC molecules with high affinity. Indeed, the MYCN protein is not expressed in human adult tissues and upregulated variably in NB cells, and MYCN peptides capable of associating to HLA-A1 or –A2 molecules with high affinity have been identified. Thus the MYCN protein qualifies as putative TAA in NB.Additional issues that determine the feasibility of targeting a putative TAA with cytotoxic T lymphocytes (CTL and will be here discussed are the following, i the inadequacy of tumor cells per se to act as antigen-presenting cells witnessed, in the case of NB cells, by the low to absent expression of HLA- class I molecules, the lack of costimulatory molecules and multiple defects in the HLA class I related antigen processing machinery, and ii the immune evasion mechanisms operated by cancer cells to fool the host immune system, such as up-regulation of soluble immunosuppressive molecules (e.g. soluble MICA and HLA-G in the case of NB or generation of immunosuppressive cells in the tumor microenvironment. A final issue that deserves consideration is the strategy used to generate

  6. MYCN: from oncoprotein to tumor-associated antigen

    Energy Technology Data Exchange (ETDEWEB)

    Pistoia, Vito; Morandi, Fabio; Pezzolo, Annalisa; Raffaghello, Lizzia; Prigione, Ignazia, E-mail: vitopistoia@ospedale-gaslini.ge.it [Laboratory of Oncology, Translational Research and Laboratory Medicine, G. Gaslini Institute, Genoa (Italy)

    2012-11-16

    MYCN is a well-known oncogene over-expressed in different human malignancies including neuroblastoma (NB), rhabdomyosarcoma, medulloblastoma, astrocytoma, Wilms’ tumor, and small cell lung cancer. In the case of NB, MYCN amplification is an established biomarker of poor-prognosis. MYCN belongs to a family of transcription factors (the most important of which is C-MYC) that show a high degree of homology. Down-regulation of MYC protein expression leads to tumor regression in animal models, indicating that MYC proteins represent interesting therapeutic targets. Pre-requisites for a candidate tumor-associated antigen (TAA) to be targeted by immunotherapeutic approaches are the following, (i) expression should be tumor-restricted, (ii) the putative TAA should be up-regulated in cancer cells, and (iii) protein should be processed into immunogenic peptides capable of associating to major histocompatibility complex molecules with high affinity. Indeed, the MYCN protein is not expressed in human adult tissues and up-regulated variably in NB cells, and MYCN peptides capable of associating to HLA-A1 or HLA-A2 molecules with high affinity have been identified. Thus the MYCN protein qualifies as putative TAA in NB. Additional issues that determine the feasibility of targeting a putative TAA with cytotoxic T lymphocytes (CTLs) and will be here discussed are the following, (i) the inadequacy of tumor cells per se to act as antigen-presenting cells witnessed, in the case of NB cells, by the low to absent expression of HLA class I molecules, the lack of co-stimulatory molecules and multiple defects in the HLA class I related antigen processing machinery, and (ii) the immune evasion mechanisms operated by cancer cells to fool the host immune system, such as up-regulation of soluble immunosuppressive molecules (e.g., soluble MICA and HLA-G in the case of NB) or generation of immunosuppressive cells in the tumor microenvironment. A final issue that deserves consideration is the

  7. ONCOLYTIC VIRUS-MEDIATED REVERSAL OF IMPAIRED TUMOR ANTIGEN PRESENTATION

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    Shashi Ashok Gujar

    2014-04-01

    Full Text Available Anti-tumor immunity can eliminate existing cancer cells and also maintain a constant surveillance against possible relapse. Such an antigen-specific adaptive response begins when tumor-specific T cells become activated. T cell activation requires two signals on antigen presenting cells (APCs: antigen presentation through MHC molecules and co-stimulation. In the absence of one or both of these signals, T cells remain inactivated or can even become tolerized. Cancer cells and their associated microenvironment strategically hinder the processing and presentation of tumor antigens and consequently prevent the development of anti-tumor immunity. Many studies, however, demonstrate that interventions that overturn tumor-associated immune evasion mechanisms can establish anti-tumor immune responses of therapeutic potential. One such intervention is oncolytic virus (OV-based anti-cancer therapy. Here we discuss how OV-induced immunological events override tumor-associated antigen presentation impairment and promote appropriate T cell:APC interaction. Detailed understanding of this phenomenon is pivotal for devising the strategies that will enhance the efficacy of OV-based anti-cancer therapy by complementing its inherent oncolytic

  8. 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.

  9. 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...

  10. The effects of a partitioned var gene repertoire of Plasmodium falciparum on antigenic diversity and the acquisition of clinical immunity

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    Arinaminpathy Nimalan

    2008-01-01

    Full Text Available Abstract Background The human malaria parasite Plasmodium falciparum exploits antigenic diversity and within-host antigenic variation to evade the host's immune system. Of particular importance are the highly polymorphic var genes that encode the family of cell surface antigens PfEMP1 (Plasmodium falciparum Erythrocyte Membrane Protein 1. It has recently been shown that in spite of their extreme diversity, however, these genes fall into distinct groups according to chromosomal location or sequence similarity, and that recombination may be confined within these groups. Methods This study presents a mathematical analysis of how recombination hierarchies affect diversity, and, by using simple stochastic simulations, investigates how intra- and inter-genic diversity influence the rate at which individuals acquire clinical immunity. Results The analysis demonstrates that the partitioning of the var gene repertoire has a limiting effect on the total diversity attainable through recombination and that the limiting effect is strongly influenced by the respective sizes of each of the partitions. Furthermore, by associating expression of one of the groups with severe malaria it is demonstrated how a small number of infections can be sufficient to protect against disease despite a seemingly limitless number of possible non-identical repertoires. Conclusion Recombination hierarchies within the var gene repertoire of P. falciparum have a severe effect on strain diversity and the process of acquiring immunity against clinical malaria. Future studies will show how the existence of these recombining groups can offer an evolutionary advantage in spite of their restriction on diversity.

  11. The Mucosal Immune System and Its Regulation by Autophagy.

    Science.gov (United States)

    Kabat, Agnieszka M; Pott, Johanna; Maloy, Kevin J

    2016-01-01

    The gastrointestinal tract presents a unique challenge to the mucosal immune system, which has to constantly monitor the vast surface for the presence of pathogens, while at the same time maintaining tolerance to beneficial or innocuous antigens. In the intestinal mucosa, specialized innate and adaptive immune components participate in directing appropriate immune responses toward these diverse challenges. Recent studies provide compelling evidence that the process of autophagy influences several aspects of mucosal immune responses. Initially described as a "self-eating" survival pathway that enables nutrient recycling during starvation, autophagy has now been connected to multiple cellular responses, including several aspects of immunity. Initial links between autophagy and host immunity came from the observations that autophagy can target intracellular bacteria for degradation. However, subsequent studies indicated that autophagy plays a much broader role in immune responses, as it can impact antigen processing, thymic selection, lymphocyte homeostasis, and the regulation of immunoglobulin and cytokine secretion. In this review, we provide a comprehensive overview of mucosal immune cells and discuss how autophagy influences many aspects of their physiology and function. We focus on cell type-specific roles of autophagy in the gut, with a particular emphasis on the effects of autophagy on the intestinal T cell compartment. We also provide a perspective on how manipulation of autophagy may potentially be used to treat mucosal inflammatory disorders.

  12. A shift in the collagen V antigenic epitope leads to T helper phenotype switch and immune response to self-antigen leading to chronic lung allograft rejection.

    Science.gov (United States)

    Tiriveedhi, V; Angaswamy, N; Brand, D; Weber, J; Gelman, A G; Hachem, R; Trulock, E P; Meyers, B; Patterson, G; Mohanakumar, T

    2012-01-01

    Immune responses to human leucocyte antigen (HLA) and self-antigen collagen V (Col-V) have been proposed in the pathogenesis of chronic rejection (bronchiolitis obliterans syndrome, BOS) following human lung transplantation (LTx). In this study, we defined the role for the shift in immunodominant epitopes of Col-V in inducing T helper phenotype switch leading to immunity to Col-V and BOS. Sera and lavage from BOS(+) LTx recipients with antibodies to Col-V were analysed. Two years prior to BOS, patients developed antibodies to both Col-V,α1(V) and α2(V) chains. However, at clinical diagnosis of BOS, antibodies became restricted to α1(V). Further, lung biopsy from BOS(+) patients bound to antibodies to α1(V), indicating that these epitopes are exposed. Fourteen Col-V peptides [pep1-14, pep1-4 specific to α1(V), pep5-8 to α1,2(V) and pep9-14 to α2(V)] which bind to HLA-DR4 and -DR7, demonstrated that prior to BOS, pep 6, 7, 9, 11 and 14 were immunodominant and induced interleukin (IL)-10. However, at BOS, the response switched to pep1, 4 and 5 and induced interferon (IFN)-γ and IL-17 responses, but not IL-10. The T helper (Th) phenotype switch is accompanied by decreased frequency of regulatory T cells (T(regs) ) in the lavage. LTx recipients with antibodies to α1(V) also demonstrated increased matrix metalloproteinase (MMP) activation with decreased MMP inhibitor, tissue inhibitor of metalloproteinase (TIMP), suggesting that MMP activation may play a role in the exposure of new Col-V antigenic epitopes. We conclude that a shift in immunodominance of self-antigenic determinants of Col-V results in induction of IFN-γ and IL-17 with loss of tolerance leading to autoimmunity to Col-V, which leads to chronic lung allograft rejection. © 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.

  13. Recurrent Vulvovaginal Candidiasis: Could It Be Related to Cell-Mediated Immunity Defect in Response to Candida Antigen?

    Directory of Open Access Journals (Sweden)

    Zahra Talaei

    2017-09-01

    Full Text Available Background Recurrent vulvovaginal candidiasis (RVVC is a common cause of morbidity affecting millions of women worldwide. Patients with RVVC are thought to have an underlying immunologic defect. This study has been established to evaluate cell-mediated immunity defect in response to candida antigen in RVVC cases. Materials and Methods Our cross-sectional study was performed in 3 groups of RVVC patients (cases, healthy individuals (control I and known cases of chronic mucocutaneous candidiasis (CMC (control II. Patients who met the inclusion criteria of RVVC were selected consecutively and were allocated in the case group. Peripheral blood mononuclear cells were isolated and labeled with CFSE and proliferation rate was measured in exposure to candida antigen via flow cytometry. Results T lymphocyte proliferation in response to candida was significantly lower in RVVC cases (n=24 and CMC patients (n=7 compared to healthy individuals (n=20, P0.05. Family history of primary immunodeficiency diseases (PID differed significantly among groups (P=0.01, RVVC patients has family history of PID more than control I (29.2 vs. 0%, P=0.008 but not statistically different from CMC patients (29.2 vs. 42.9%, P>0.05. Prevalence of atopy was greater in RVVC cases compared to healthy individuals (41.3 vs. 15%, P=0.054. Lymphoproliferative activity and vaginal symptoms were significantly different among RVVC cases with and without allergy (P=0.01, P=0.02. Conclusion Our findings revealed that T cells do not actively proliferate in response to Candida antigen in some RVVC cases. So it is concluded that patients with cell-mediated immunity defect are more susceptible to recurrent fungal infections of vulva and vagina. Nonetheless, some other cases of RVVC showed normal function of T cells. Further evaluations showed that these patients suffer from atopy. It is hypothesized that higher frequency of VVC in patients with history of atopy might be due to allergic response

  14. How Does HTLV-1 Undergo Oncogene-Dependent Replication Despite a Strong Immune Response?

    Directory of Open Access Journals (Sweden)

    Hélène Gazon

    2018-01-01

    Full Text Available In 1987, Mitsuaki Yoshida proposed the following model (Yoshida and Seiki, 1987: “... T-cells activated through the endogenous p40x would express viral antigens including the envelope glycoproteins which are exposed on the cell surface. These glycoproteins are targets of host immune surveillance, as is evidenced by the cytotoxic effects of anti-envelope antibodies or patient sera. Eventually all cells expressing the viral antigens, that is, all cells driven by the p40x would be rejected by the host. Only those cells that did not express the viral antigens would survive. Later, these antigen-negative infected cells would begin again to express viral antigens, including p40x, thus entering into the second cycle of cell propagation. These cycles would be repeated in so-called healthy virus carriers for 20 or 30 years or longer....” Three decades later, accumulated experimental facts particularly on intermittent viral transcription and regulation by the host immune response appear to prove that Yoshida was right. This Hypothesis and Theory summarizes the evidences that support this paradigm.

  15. Targeting Autophagy in the Tumor Microenvironment: New Challenges and Opportunities for Regulating Tumor Immunity

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    Bassam Janji

    2018-04-01

    Full Text Available Cancer cells evolve in the tumor microenvironment, which is now well established as an integral part of the tumor and a determinant player in cancer cell adaptation and resistance to anti-cancer therapies. Despite the remarkable and fairly rapid progress over the past two decades regarding our understanding of the role of the tumor microenvironment in cancer development, its precise contribution to cancer resistance is still fragmented. This is mainly related to the complexity of the “tumor ecosystem” and the diversity of the stromal cell types that constitute the tumor microenvironment. Emerging data indicate that several factors, such as hypoxic stress, activate a plethora of resistance mechanisms, including autophagy, in tumor cells. Hypoxia-induced autophagy in the tumor microenvironment also activates several tumor escape mechanisms, which effectively counteract anti-tumor immune responses mediated by natural killer and cytotoxic T lymphocytes. Therefore, strategies aiming at targeting autophagy in cancer cells in combination with other therapeutic strategies have inspired significant interest to overcome immunological tolerance and promote tumor regression. However, a number of obstacles still hamper the application of autophagy inhibitors in clinics. First, the lack of selectivity of the current pharmacological inhibitors of autophagy makes difficult to draw a clear statement about its effective contribution in cancer. Second, autophagy has been also described as an important mechanism in tumor cells involved in presentation of antigens to T cells. Third, there is a circumstantial evidence that autophagy activation in some innate immune cells may support the maturation of these cells, and it is required for their anti-tumor activity. In this review, we will address these aspects and discuss our current knowledge on the benefits and the drawbacks of targeting autophagy in the context of anti-tumor immunity. We believe that it is

  16. Imaging Polarized Secretory Traffic at the Immune Synapse in Living T Lymphocytes.

    Science.gov (United States)

    Calvo, Víctor; Izquierdo, Manuel

    2018-01-01

    Immune synapse (IS) formation by T lymphocytes constitutes a crucial event involved in antigen-specific, cellular and humoral immune responses. After IS formation by T lymphocytes and antigen-presenting cells, the convergence of secretory vesicles toward the microtubule-organizing center (MTOC) and MTOC polarization to the IS are involved in polarized secretion at the synaptic cleft. This specialized mechanism appears to specifically provide the immune system with a fine strategy to increase the efficiency of crucial secretory effector functions of T lymphocytes, while minimizing non-specific, cytokine-mediated stimulation of bystander cells, target cell killing and activation-induced cell death. The molecular bases involved in the polarized secretory traffic toward the IS in T lymphocytes have been the focus of interest, thus different models and several imaging strategies have been developed to gain insights into the mechanisms governing directional secretory traffic. In this review, we deal with the most widely used, state-of-the-art approaches to address the molecular mechanisms underlying this crucial, immune secretory response.

  17. Targeted delivery of TLR ligands to human and mouse dendritic cells strongly enhances adjuvanticity.

    Science.gov (United States)

    Tacken, Paul J; Zeelenberg, Ingrid S; Cruz, Luis J; van Hout-Kuijer, Maaike A; van de Glind, Gerline; Fokkink, Remco G; Lambeck, Annechien J A; Figdor, Carl G

    2011-12-22

    Effective vaccines consist of 2 components: immunodominant antigens and effective adjuvants. Whereas it has been demonstrated that targeted delivery of antigens to dendritic cells (DCs) improves vaccine efficacy, we report here that co-targeting of TLR ligands (TLRLs) to DCs strongly enhances adjuvanticity and immunity. We encapsulated ligands for intracellular TLRs within biodegradable nanoparticles coated with Abs recognizing DC-specific receptors. Targeted delivery of TLRLs to human DCs enhanced the maturation and production of immune stimulatory cytokines and the Ag-specific activation of naive CD8(+) T cells. In vivo studies demonstrated that nanoparticles carrying Ag induced cytotoxic T-lymphocyte responses at 100-fold lower adjuvant dose when TLRLs were co-encapsulated instead of administered in soluble form. Moreover, the efficacy of these targeted TLRLs reduced the serum cytokine storm and related toxicity that is associated with administration of soluble TLRLs. We conclude that the targeted delivery of adjuvants may improve the efficacy and safety of DC-based vaccines.

  18. Emerging functions of natural IgM and its Fc receptor FCMR in immune homeostasis

    Directory of Open Access Journals (Sweden)

    Hongsheng eWang

    2016-03-01

    Full Text Available Most natural IgM antibodies are encoded by germline Ig sequences and are produced in large quantities by both mice and humans in the absence of intentional immunization. Natural IgM are reactive with many conserved epitopes, including those shared by microorganisms and autoantigens. As a result, these antibodies play important roles in clearing intruding pathogens, as well as apoptotic/necrotic cells and otherwise damaged tissues. While natural IgM binds to target structures with low affinity due to a lack of significant selection by somatic hypermutation, its pentameric structure with 10 antigen binding sites enables these antibodies to bind multivalent target antigens with high avidity. Opsonization of antigen complexed with IgM is mediated by cell surface Fc receptors. While the existence of Fc alpha/mu receptor has been known for some time, only recently has the Fc receptor specific for IgM (FCMR been identified. In this review, we focus on our current understandings of how natural IgM and FCMR regulate the immune system and maintain homeostasis under physiological and pathological conditions.

  19. Toll-like receptors as targets for immune disorders.

    LENUS (Irish Health Repository)

    Keogh, Brian

    2012-02-01

    Since the identification of the first Toll-like receptor (TLR) in humans in 1997, understanding of the molecular basis for innate immunity has increased significantly. The TLR family and downstream signalling pathways have been extensively characterised, There is now significant evidence suggesting a role for TLRs in human inflammatory and immune diseases such as rheumatoid arthritis, diabetes, allergy\\/asthma and atherosclerosis. Various approaches have been taken to identify novel therapeutic agents targeting TLRs including biologics, small molecules and nucleic acid-based drugs. Several are now being evaluated in the clinic and showing promise against various diseases. This review paper outlines the recent advances in the understanding of TLR biology and highlights novel TLR agonists and antagonists in development for the treatment of immune diseases.

  20. Human Tregs Made Antigen Specific by Gene Modification: The Power to Treat Autoimmunity and Antidrug Antibodies with Precision

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    Patrick R. Adair

    2017-09-01

    Full Text Available Human regulatory CD4+ T cells (Tregs are potent immunosuppressive lymphocytes responsible for immune tolerance and homeostasis. Since the seminal reports identifying Tregs, vast research has been channeled into understanding their genesis, signature molecular markers, mechanisms of suppression, and role in disease. This research has opened the doors for Tregs as a potential therapeutic for diseases and disorders such as multiple sclerosis, type I diabetes, transplantation, and immune responses to protein therapeutics, like factor VIII. Seminal clinical trials have used polyclonal Tregs, but the frequency of antigen-specific Tregs among polyclonal populations is low, and polyclonal Tregs may risk non-specific immunosuppression. Antigen-specific Treg therapy, which uses genetically modified Tregs expressing receptors specific for target antigens, greatly mitigates this risk. Building on the principles of T-cell receptor cloning, chimeric antigen receptors (CARs, and a novel CAR derivative, called B-cell antibody receptors, our lab has developed different types of antigen-specific Tregs. This review discusses the current research and optimization of gene-modified antigen-specific human Tregs in our lab in several disease models. The preparations and considerations for clinical use of such Tregs also are discussed.

  1. Synergistic immune responses induced by endogenous retrovirus and herpesvirus antigens result in increased production of inflammatory cytokines in multiple sclerosis patients

    DEFF Research Database (Denmark)

    Brudek, T; Christensen, T; Hansen, H J

    2008-01-01

    Human endogenous retroviruses (HERV) and herpesviruses are increasingly associated with the pathogenesis of the neurological inflammatory disease multiple sclerosis (MS). Herpesviruses are capable of HERV activation and simultaneous presence of HERV and herpesvirus antigens have a synergistic...... effect on cell-mediated immune responses, which tend to be higher in MS patients in comparison with healthy individuals. Here, we investigate whether these synergistic immune responses are reflected in changes in the production of proinflammatory cytokines. Using enzyme-linked immunosorbent assays...

  2. Commercial bacterins did not induce detectable levels of antibodies in mice against Mycoplasma hyopneumoniae antigens strongly recognized by swine immune system

    Directory of Open Access Journals (Sweden)

    Andressa Fisch

    2016-01-01

    Full Text Available Enzootic Pneumonia (EP caused by Mycoplasma hyopneumoniae results in major economic losses to the swine industry. Hence, the identification of factors that provide protection against EP could help to develop effective vaccines. One such factor that provides partial protection are bacterins. Therefore, the aim of this study was to verify the induction of antibodies against fifteen M. hyopneumoniae antigens, strongly recognized by the swine immune system during natural infection, in mice vaccinated with six commercial bacterins. Each group of mice was inoculated with one bacterin, and seroconversion was assessed by indirect ELISA using recombinant antigens and M. hyopneumoniae 7448 whole cell extract. Sera from one inoculated group recognized antigen MHP_0067, and sera from four inoculated groups recognized antigens MHP_0513 and MHP_0580. None of the bacterins was able to induce seroconversion against the twelve remaining antigens. This absence of a serological response could be attributed to the lack of antigen expression in M. hyopneumoniae strains used in bacterin production. Additionally the partial protection provided by these vaccines could be due to low expression or misfolding of antigens during vaccine preparation. Therefore, the supplementation of bacterins with these recombinant antigens could be a potential alternative in the development of more effective vaccines.

  3. Humoral and cellular immune response in mice induced by the classical swine fever virus E2 protein fused to the porcine CD154 antigen.

    Science.gov (United States)

    Sordo, Yusmel; Suárez, Marisela; Caraballo, Rosalina; Sardina, Talía; Brown, Emma; Duarte, Carlos; Lugo, Joanna; Gil, Lázaro; Perez, Danny; Oliva, Ayme; Vargas, Milagros; Santana, Elaine; Valdés, Rodolfo; Rodríguez, María Pilar

    2018-03-01

    The development of subunit vaccines against classical swine fever is a desirable goal, because it allows discrimination between vaccinated and infected animals. In this study, humoral and cellular immune response elicited in inbred BALB/c mice by immunization with a recombinant classical swine fever virus (CSFV) E2 protein fused to porcine CD154 antigen (E2CD154) was assessed. This model was used as a predictor of immune response in swine. Mice were immunized with E2CD154 emulsified in Montanide ISA50V2 or dissolved in saline on days 1 and 21. Another group received E2His antigen, without CD154, in the same adjuvant. Montanide ISA50V2 or saline served as negative controls for each experimental group. Animals immunized with 12.5 and 2.5 μg/dose of E2CD154 developed the highest titers (>1:2000) of CSFV neutralizing antibodies. Moreover, CSFV specific splenocyte gamma-interferon production, measured after seven and twenty-eight days of immunization, was significantly higher in mice immunized with 12.5 μg of E2CD154. As a conclusion, E2CD154 emulsified in Montanide ISA50 V2 was able to induce a potent humoral and an early cellular immune response in inbred BALB/c mice. Therefore, this immunogen might be an appropriate candidate to elicit immune response in swine, control CSF disease and to eliminate CSFV in swine. Copyright © 2018 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  4. Statistical prediction of immunity to placental malaria based on multi-assay antibody data for malarial antigens

    DEFF Research Database (Denmark)

    Siriwardhana, Chathura; Fang, Rui; Salanti, Ali

    2017-01-01

    Background Plasmodium falciparum infections are especially severe in pregnant women because infected erythrocytes (IE) express VAR2CSA, a ligand that binds to placental trophoblasts, causing IE to accumulate in the placenta. Resulting inflammation and pathology increases a woman’s risk of anemia...... to 28 malarial antigens and used the data to develop statistical models for predicting if a woman has sufficient immunity to prevent PM. Methods Archival plasma samples from 1377 women were screened in a bead-based multiplex assay for Ab to 17 VAR2CSA-associated antigens (full length VAR2CSA (FV2), DBL...... in the following seven statistical approaches: logistic regression full model, logistic regression reduced model, recursive partitioning, random forests, linear discriminant analysis, quadratic discriminant analysis, and support vector machine. Results The best and simplest model proved to be the logistic...

  5. Immune selection and within-host competition can structure the repertoire of variant surface antigens in Plasmodium falciparum -a mathematical model

    DEFF Research Database (Denmark)

    van Noort, Sander P; Nunes, Marta C; Weedall, Gareth D

    2010-01-01

    BACKGROUND: The evolutionary mechanisms structuring the expression pattern of variant surface antigen (VSA) families that allow pathogens to evade immune responses and establish chronic and repeated infections pose major challenges to theoretical research. In Plasmodium falciparum, the best...... subset of PfEMP1 variants tends to dominate in non-immune patients and in patients with severe malaria, while more diverse subsets relate to uncomplicated infection and higher levels of pre-existing protective immunity. METHODOLOGY/PRINCIPAL FINDINGS: Here, we use the available molecular and serological......-host and diverse blocks that are favoured by immune selection at the population level. CONCLUSIONS/SIGNIFICANCE: The application of a monotonic dominance profile to VSAs encoded by a gene family generates two opposing selective forces and, consequently, two distinct clusters of genes emerge in adaptation to naïve...

  6. Structural and Nonstructural Viral Proteins Are Targets of T-Helper Immune Response against Human Respiratory Syncytial Virus.

    Science.gov (United States)

    Lorente, Elena; Barriga, Alejandro; Barnea, Eilon; Mir, Carmen; Gebe, John A; Admon, Arie; López, Daniel

    2016-06-01

    Proper antiviral humoral and cellular immune responses require previous recognition of viral antigenic peptides that are bound to HLA class II molecules, which are exposed on the surface of antigen-presenting cells. The helper immune response is critical for the control and the clearance of human respiratory syncytial virus (HRSV) infection, a virus with severe health risk in infected pediatric, immunocompromised, and elderly populations. In this study, using a mass spectrometry analysis of complex HLA class II-bound peptide pools that were isolated from large amounts of HRSV-infected cells, 19 naturally processed HLA-DR ligands, most of them included in a complex nested set of peptides, were identified. Both the immunoprevalence and the immunodominance of the HLA class II response to HRSV were focused on one nonstructural (NS1) and two structural (matrix and mainly fusion) proteins of the infective virus. These findings have clear implications for analysis of the helper immune response as well as for antiviral vaccine design. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Epstein-Barr Virus-Specific Humoral Immune Responses in Health and Disease.

    Science.gov (United States)

    Middeldorp, Jaap M

    2015-01-01

    Epstein-Barr virus (EBV) is widely distributed in the world and associated with a still increasing number of acute, chronic, malignant and autoimmune disease syndromes. Humoral immune responses to EBV have been studied for diagnostic, pathogenic and protective (vaccine) purposes. These studies use a range of methodologies, from cell-based immunofluorescence testing to antibody-diversity analysis using immunoblot and epitope analysis using recombinant or synthetic peptide-scanning. First, the individual EBV antigen complexes (VCA , MA, EA(D), EA(R) and EBNA) are defined at cellular and molecular levels, providing a historic overview. The characteristic antibody responses to these complexes in health and disease are described, and differences are highlighted by clinical examples. Options for EBV vaccination are briefly addressed. For a selected number of immunodominant proteins, in particular EBNA1, the interaction with human antibodies is further detailed at the epitope level, revealing interesting insights for structure, function and immunological aspects, not considered previously. Humoral immune responses against EBV-encoded tumour antigens LMP1, LMP2 and BARF1 are addressed, which provide novel options for targeted immunotherapy. Finally, some considerations on EBV-linked autoimmune diseases are given, and mechanisms of antigen mimicry are briefly discussed. Further analysis of humoral immune responses against EBV in health and disease in carefully selected patient cohorts will open new options for understanding pathogenesis of individual EBV-linked diseases and developing targeted diagnostic and therapeutic approaches.

  8. Cell-mediated immune responses in rainbow trout after DNA immunization against the viral hemorrhagic septicemia virus

    DEFF Research Database (Denmark)

    Utke, Katrin; Kock, Holger; Schuetze, Heike

    2008-01-01

    injection site rather than to injection sites of heterologous vaccines, suggesting the antigen specificity of homing. By demonstrating CMC responses to distinct viral proteins and homing in rainbow trout, these results substantially contribute to the understanding of the teleost immune system.......To identify viral proteins that induce cell-mediated cytotoxicity (CMC) against viral hemorrhagic septicemia virus (VHSV)-infected cells, rainbow trout were immunized with DNA vectors encoding the glycoprotein G or the nucleocapsid protein N of VHSV. The G protein was a more potent trigger...... of cytotoxic cells than the N protein. Peripheral blood leukocytes (PBL) isolated from trout immunized against the G protein killed both VHSV-infected MHC class I matched (RTG-2) and VHSV-infected xenogeneic (EPC) target cells, suggesting the involvement of both cytotoxic T lymphocytes (CTL) and NK cells...

  9. Combined local and systemic immunization is essential for durable T-cell mediated heterosubtypic immunity against influenza A virus

    DEFF Research Database (Denmark)

    Uddbäck, Ida Elin Maria; Pedersen, Line M I; Pedersen, Sara R

    2016-01-01

    nucleoprotein have previously been found to induce short-term protection in mice. In this study we confirm that systemic (subcutaneous (s.c.) immunization rapidly induced heterosubtypic protection predominantly mediated by CD8 T cells, but within three months clinical protection completely disappeared. Local......The threat from unpredictable influenza virus pandemics necessitates the development of a new type of influenza vaccine. Since the internal proteins are highly conserved, induction of T cells targeting these antigens may provide the solution. Indeed, adenoviral (Ad) vectors expressing flu...... (intranasal (i.n.)) immunization elicited delayed, but more lasting protection despite relatively inefficient immunization. However, by far, the most robust protection was induced by simultaneous, combined (i.n. + s.c.) vaccination, and, notably, in this case clinical protection lasted at least 8 months...

  10. Plasmodium vivax VIR Proteins Are Targets of Naturally-Acquired Antibody and T Cell Immune Responses to Malaria in Pregnant Women.

    Science.gov (United States)

    Requena, Pilar; Rui, Edmilson; Padilla, Norma; Martínez-Espinosa, Flor E; Castellanos, Maria Eugenia; Bôtto-Menezes, Camila; Malheiro, Adriana; Arévalo-Herrera, Myriam; Kochar, Swati; Kochar, Sanjay K; Kochar, Dhanpat K; Umbers, Alexandra J; Ome-Kaius, Maria; Wangnapi, Regina; Hans, Dhiraj; Menegon, Michela; Mateo, Francesca; Sanz, Sergi; Desai, Meghna; Mayor, Alfredo; Chitnis, Chetan C; Bardají, Azucena; Mueller, Ivo; Rogerson, Stephen; Severini, Carlo; Fernández-Becerra, Carmen; Menéndez, Clara; Del Portillo, Hernando; Dobaño, Carlota

    2016-10-01

    P. vivax infection during pregnancy has been associated with poor outcomes such as anemia, low birth weight and congenital malaria, thus representing an important global health problem. However, no vaccine is currently available for its prevention. Vir genes were the first putative virulent factors associated with P. vivax infections, yet very few studies have examined their potential role as targets of immunity. We investigated the immunogenic properties of five VIR proteins and two long synthetic peptides containing conserved VIR sequences (PvLP1 and PvLP2) in the context of the PregVax cohort study including women from five malaria endemic countries: Brazil, Colombia, Guatemala, India and Papua New Guinea (PNG) at different timepoints during and after pregnancy. Antibody responses against all antigens were detected in all populations, with PNG women presenting the highest levels overall. P. vivax infection at sample collection time was positively associated with antibody levels against PvLP1 (fold-increase: 1.60 at recruitment -first antenatal visit-) and PvLP2 (fold-increase: 1.63 at delivery), and P. falciparum co-infection was found to increase those responses (for PvLP1 at recruitment, fold-increase: 2.25). Levels of IgG against two VIR proteins at delivery were associated with higher birth weight (27 g increase per duplicating antibody levels, ppregnant women had significantly higher antigen-specific IFN-γ TH1 responses (p=0.006) and secreted less pro-inflammatory cytokines TNF and IL-6 after PvLP2 stimulation than P. vivax-infected women (p<0.05). These data demonstrate that VIR antigens induce the natural acquisition of antibody and T cell memory responses that might be important in immunity to P. vivax during pregnancy in very diverse geographical settings.

  11. Immune markers and correlates of protection for vaccine induced immune responses

    DEFF Research Database (Denmark)

    Thakur, Aneesh; Pedersen, Lasse Eggers; Jungersen, Gregers

    2012-01-01

    of an appropriate humoral response currently remain the best validated correlates of protective immunity after vaccination. Despite advancements in the field of immunology over the past few decades currently there are, however, no sufficiently validated immune correlates of vaccine induced protection against......-specific production of interferon-gamma (IFN-γ) has been promoted as a quantitative marker of protective cell-mediated immune responses over the past couple of decades. More recently, however, evidence from several infections has pointed towards the quality of the immune response, measured through increased levels...... of antigen-specific polyfunctional T cells capable of producing a triad of relevant cytokines, as a better correlate of sustained protective immunity against this type of infections. Also the possibilities to measure antigen-specific cytotoxic T cells (CTL) during infection or in response to vaccination...

  12. In Vitro Variant Surface Antigen Expression in Plasmodium falciparum Parasites from a Semi-Immune Individual Is Not Correlated with Var Gene Transcription

    Science.gov (United States)

    Tschan, Serena; Flötenmeyer, Matthias; Koch, Iris; Berger, Jürgen; Kremsner, Peter; Frank, Matthias

    2016-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is considered to be the main variant surface antigen (VSA) of Plasmodium falciparum and is mainly localized on electron-dense knobs in the membrane of the infected erythrocyte. Switches in PfEMP1 expression provide the basis for antigenic variation and are thought to be critical for parasite persistence during chronic infections. Recently, strain transcending anti-PfEMP1 immunity has been shown to develop early in life, challenging the role of PfEMP1 in antigenic variation during chronic infections. In this work we investigate how P. falciparum achieves persistence during a chronic asymptomatic infection. The infected individual (MOA) was parasitemic for 42 days and multilocus var gene genotyping showed persistence of the same parasite population throughout the infection. Parasites from the beginning of the infection were adapted to tissue culture and cloned by limiting dilution. Flow cytometry using convalescent serum detected a variable surface recognition signal on isogenic clonal parasites. Quantitative real-time PCR with a field isolate specific var gene primer set showed that the surface recognition signal was not correlated with transcription of individual var genes. Strain transcending anti-PfEMP1 immunity of the convalescent serum was demonstrated with CD36 selected and PfEMP1 knock-down NF54 clones. In contrast, knock-down of PfEMP1 did not have an effect on the antibody recognition signal in MOA clones. Trypsinisation of the membrane surface proteins abolished the surface recognition signal and immune electron microscopy revealed that antibodies from the convalescent serum bound to membrane areas without knobs and with knobs. Together the data indicate that PfEMP1 is not the main variable surface antigen during a chronic infection and suggest a role for trypsin sensitive non-PfEMP1 VSAs for parasite persistence in chronic infections. PMID:27907004

  13. 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.

  14. Differential Patterns of Large Tumor Antigen-Specific Immune Responsiveness in Patients with BK Polyomavirus-Positive Prostate Cancer or Benign Prostatic Hyperplasia

    Science.gov (United States)

    Sais, Giovanni; Wyler, Stephen; Hudolin, Tvrtko; Banzola, Irina; Mengus, Chantal; Bubendorf, Lukas; Wild, Peter J.; Hirsch, Hans H.; Sulser, Tullio; Spagnoli, Giulio C.

    2012-01-01

    The role of the polyomavirus BK (BKV) large tumor antigen (L-Tag) as a target of immune response in patients with prostate cancer (PCa) has not been investigated thus far. In this study, we comparatively analyzed humoral and cellular L-Tag-specific responsiveness in age-matched patients bearing PCa or benign prostatic hyperplasia, expressing or not expressing BKV L-Tag-specific sequences in their tissue specimens, and in non-age-matched healthy individuals. Furthermore, results from patients with PCa were correlated to 5-year follow-up clinical data focusing on evidence of biochemical recurrence (BR) after surgery (prostate specific antigen level of ≥0.2 ng/ml). In peripheral blood mononuclear cells (PBMC) from patients with PCa with evidence of BR and BKV L-Tag-positive tumors, stimulation with peptides derived from the BKV L-Tag but not those derived from Epstein-Barr virus, influenza virus, or cytomegalovirus induced a peculiar cytokine gene expression profile, characterized by high expression of interleukin-10 (IL-10) and transforming growth factor β1 and low expression of gamma interferon genes. This pattern was confirmed by protein secretion data and correlated with high levels of anti-BKV L-Tag IgG. Furthermore, in PBMC from these PCa-bearing patients, L-Tag-derived peptides significantly expanded an IL-10-secreting CD4+ CD25+(high) CD127− FoxP3+ T cell population with an effector memory phenotype (CD103+) capable of inhibiting proliferation of autologous anti-CD3/CD28-triggered CD4+ CD25− T cells. Collectively, our findings indicate that potentially tolerogenic features of L-Tag-specific immune response are significantly associated with tumor progression in patients with BKV+ PCa. PMID:22647697

  15. Expression of variant surface antigens by Plasmodium falciparum parasites in the peripheral blood of clinically immune pregnant women indicates ongoing placental infection

    DEFF Research Database (Denmark)

    Ofori, Michael F; Staalsoe, Trine; Bam, Victoria

    2003-01-01

    Placenta-sequestered Plasmodium falciparum parasites that cause pregnancy-associated malaria (PAM) in otherwise clinically immune women express distinct variant surface antigens (VSA(PAM)) not expressed by parasites in nonpregnant individuals. We report here that parasites from the peripheral blood...... of clinically immune pregnant women also express VSA(PAM), making them a convenient source of VSA(PAM) expressors for PAM vaccine research....

  16. Evaluation of local immune response to Fasciola hepatica experimental infection in the liver and hepatic lymph nodes of goats immunized with Sm14 vaccine antigen

    Directory of Open Access Journals (Sweden)

    Ricardo E Mendes

    2010-08-01

    Full Text Available Protection against Fasciola hepatica in goats immunized with a synthetic recombinant antigen from Schistosoma mansoni fatty acid-binding protein 14 (rSm14 was investigated by assessing worm burdens, serum levels of hepatic enzymes, faecal egg count and hepatic damage, which was evaluated using gross and microscopic morphometric observation. The nature of the local immune response was assessed by examining the distribution of CD2+, CD4+, CD8+ and γ´+ T lymphocytes along with IgG+, IL-4+ and IFN-γ+ cells in the liver and hepatic lymph nodes (HLN. The goats used consisted of group 1 (unimmunized and uninfected, group 2 [infected control - immunized with Quillaia A (Quil A] and group 3 (immunized with rSm14 in Quil A and infected, each containing seven animals. Immunization with rSm14 in Quil A adjuvant induced a reduction in gross hepatic lesions of 56.6% (p < 0.001 and reduced hepatic and HLN infiltration of CD2+, CD4+, CD8+ and γ´+ T lymphocytes as well as IL-4+ and IFN-γ+ cells (p < 0.05. This is the first report of caprine immunization against F. hepatica using a complete rSm14 molecule derived from S. mansoni. Immunization reduced hepatic damage and local inflammatory infiltration into the liver and HLN. However, considering that Quil A is not the preferential/first choice adjuvant for Sm14 immunization, further studies will be undertaken using the monophosphoryl lipid A-based family of adjuvants during clinical trials to facilitate anti-Fasciolavaccine development.

  17. Involvement of T- and B-lymphocytes in the immune response to the protein exotoxin and the lipopolysaccharide antigens of Vibrio cholerae

    International Nuclear Information System (INIS)

    Kateley, J.R.; Patel, C.B.; Friedman, H.

    1975-01-01

    The immune response at the level of individual immunocytes to the somatic lipopolysaccharide antigen derived from whole Vibrio cholerae and to the purified protein exotoxin from this organism were studied in terms of the role of T- and B-lymphocytes. By adoptive cell transfer studies with irradiated recipient mice, it was shown that normal spleen cells from normal syngeneic mice could readily transfer the capability of responding to both types of cholera antigens. However, when the spleen cells were depleted of T-cells with anti-theta serum and complement, antibody responsiveness to the LPS antigen, but not the exotoxin, could be achieved in recipients. Furthermore, by appropriate transfer of either bone marrow, thymus, or thymus-marrow cell mixtures to irradiated mice, it was shown that the response to the cholera somatic antigen was relatively independent of thymus cells, whereas the response to exotoxin required ''helper'' T-cells

  18. The subcutaneous inoculation of pH 6 antigen mutants of Yersinia pestis does not affect virulence and immune response in mice.

    Science.gov (United States)

    Anisimov, Andrey P; Bakhteeva, Irina V; Panfertsev, Evgeniy A; Svetoch, Tat'yana E; Kravchenko, Tat'yana B; Platonov, Mikhail E; Titareva, Galina M; Kombarova, Tat'yana I; Ivanov, Sergey A; Rakin, Alexander V; Amoako, Kingsley K; Dentovskaya, Svetlana V

    2009-01-01

    Two isogenic sets of Yersinia pestis strains were generated, composed of wild-type strains 231 and I-1996, their non-polar pH 6(-) mutants with deletions in the psaA gene that codes for its structural subunit or the whole operon, as well as strains with restored ability for temperature- and pH-dependent synthesis of adhesion pili or constitutive production of pH 6 antigen. The mutants were generated by site-directed mutagenesis of the psa operon and subsequent complementation in trans. It was shown that the loss of synthesis or constitutive production of pH 6 antigen did not influence Y. pestis virulence or the average survival time of subcutaneously inoculated BALB/c naïve mice or animals immunized with this antigen.

  19. Effect of immunization against ox-LDL with two different antigens on formation and development of atherosclerosis

    Directory of Open Access Journals (Sweden)

    Saberi Salb-Ali

    2007-11-01

    Full Text Available Abstract Background Several studies were pointed to oxidized LDL (ox-LDL as one of the main immunogenes which have important roles in primary lesions of atherosclerosis. In this study, by immunization against ox-LDL with two different antigens in an animal model (rabbit and consideration of its effect on two different dietary regimens; we tried to clear relation between immune system and atherosclerosis. Methods LDL was isolated from hypercholesterolemic rabbits plasma and oxidized with MDA or Cu++. Rabbits were divided to three groups and immunized with MDA-LDL or Cu-LDL or phosphate-buffer (PBS as a control group. Immunization was repeated after 2, 4, 6, and 8 weeks and concentration of antibodies against ox-LDL was measured in each stage. After immunization, rabbits in each group were divided to two subgroups based on the dietary regimen (fed normal or high cholesterol diet. At the beginning and the end of the study, biochemical factors were measured. Also, fatty streaks in aorta and left and right coronary arteries evaluated. Results Immunization with Cu2+-LDL and MDA-LDL induced statistically significant antibodies against ox-LDL. In hypercholesterolemic rabbits immunized with MDA-LDL the level of cholesterol, LDL-cholesterol, triglyceride, fasting blood sugar and fatty streak lesions in aorta and right coronary arteries were significantly decreased as compared with non-immunized high-cholesterol group. Immunization with Cu2+-LDL in hypercholesterolemic rabbits significantly decreased triglyceride, fasting blood sugar, cholesterol and CRP. No significant differences were detected in the fatty streak lesions in this group as compared with non-immunized high-cholesterol diet. In groups under normal diet immunized with MDA-LDL or Cu2+-LDL no significant effect on biochemical factors and atherosclerotic lesions were observed. Conclusion This study indicates that although the effect of produced antibodies in several methods and different dietary

  20. A novel ex vivo immunoproteomic approach characterising Fasciola hepatica tegumental antigens identified using immune antibody from resistant sheep.

    Science.gov (United States)

    Cameron, Timothy C; Cooke, Ira; Faou, Pierre; Toet, Hayley; Piedrafita, David; Young, Neil; Rathinasamy, Vignesh; Beddoe, Travis; Anderson, Glenn; Dempster, Robert; Spithill, Terry W

    2017-08-01

    A more thorough understanding of the immunological interactions between Fasciola spp. and their hosts is required if we are to develop new immunotherapies to control fasciolosis. Deeper knowledge of the antigens that are the target of the acquired immune responses of definitive hosts against both Fasciola hepatica and Fasciola gigantica will potentially identify candidate vaccine antigens. Indonesian Thin Tail sheep express a high level of acquired immunity to infection by F. gigantica within 4weeks of infection and antibodies in Indonesian Thin Tail sera can promote antibody-dependent cell-mediated cytotoxicity against the surface tegument of juvenile F. gigantica in vitro. Given the high protein sequence similarity between F. hepatica and F. gigantica, we hypothesised that antibody from F. gigantica-infected sheep could be used to identify the orthologous proteins in the tegument of F. hepatica. Purified IgG from the sera of F. gigantica-infected Indonesian Thin Tail sheep collected pre-infection and 4weeks p.i. were incubated with live adult F. hepatica ex vivo and the immunosloughate (immunoprecipitate) formed was isolated and analysed via liquid chromatography-electrospray ionisation-tandem mass spectrometry to identify proteins involved in the immune response. A total of 38 proteins were identified at a significantly higher abundance in the immunosloughate using week 4 IgG, including eight predicted membrane proteins, 20 secreted proteins, nine proteins predicted to be associated with either the lysosomes, the cytoplasm or the cytoskeleton and one protein with an unknown cellular localization. Three of the membrane proteins are transporters including a multidrug resistance protein, an amino acid permease and a glucose transporter. Interestingly, a total of 21 of the 38 proteins matched with proteins recently reported to be associated with the proposed small exosome-like extracellular vesicles of adult F. hepatica, suggesting that the Indonesian Thin Tail week

  1. Expression of H5 hemagglutinin vaccine antigen in common duckweed (Lemna minor) protects against H5N1 high pathogenicity avian influenza virus challenge in immunized chickens.

    Science.gov (United States)

    Bertran, Kateri; Thomas, Colleen; Guo, Xuan; Bublot, Michel; Pritchard, Nikki; Regan, Jeffrey T; Cox, Kevin M; Gasdaska, John R; Dickey, Lynn F; Kapczynski, Darrell R; Swayne, David E

    2015-07-09

    A synthetic hemagglutinin (HA) gene from the highly pathogenic avian influenza (HPAI) virus A/chicken/Indonesia/7/2003 (H5N1) (Indo/03) was expressed in aquatic plant Lemna minor (rLemna-HA). In Experiment 1, efficacy of rLemna-HA was tested on birds immunized with 0.2μg or 2.3 μg HA and challenged with 10(6) mean chicken embryo infectious doses (EID50) of homologous virus strain. Both dosages of rLemna-HA conferred clinical protection and dramatically reduced viral shedding. Almost all the birds immunized with either dosage of rLemna-HA elicited HA antibody titers against Indo/03 antigen, suggesting an association between levels of anti-Indo/03 antibodies and protection. In Experiment 2, efficacy of rLemna-HA was tested on birds immunized with 0.9 μg or 2.2 μg HA and challenged with 10(6) EID50 of heterologous H5N1 virus strains A/chicken/Vietnam/NCVD-421/2010 (VN/10) or A/chicken/West Java/PWT-WIJ/2006 (PWT/06). Birds challenged with VN/10 exhibited 100% survival regardless of immunization dosage, while birds challenged with PWT/06 had 50% and 30% mortality at 0.9 μg HA and 2.2 μg HA, respectively. For each challenge virus, viral shedding titers from 2.2 μg HA vaccinated birds were significantly lower than those from 0.9μg HA vaccinated birds, and titers from both immunized groups were in turn significantly lower than those from sham vaccinated birds. Even if immunized birds elicited HA titers against the vaccine antigen Indo/03, only the groups challenged with VN/10 developed humoral immunity against the challenge antigen. None (rLemna-HA 0.9 μg HA) and 40% (rLemna-HA 2.2 μg HA) of the immunized birds challenged with PWT/06 elicited pre-challenge antibody titers, respectively. In conclusion, Lemna-expressed HA demonstrated complete protective immunity against homologous challenge and suboptimal protection against heterologous challenge, the latter being similar to results from inactivated whole virus vaccines. Transgenic duckweed-derived HA could be a

  2. Immunization of C57BL/6 Mice with GRA2 Combined with MPL Conferred Partial Immune Protection against Toxoplasma gondii

    Science.gov (United States)

    Babaie, Jalal; Amiri, Samira; Homayoun, Robab; Azimi, Ebrahim; Mohabati, Reyhaneh; Berizi, Mahboobe; Sadaie, M. Reza; Golkar, Majid

    2018-01-01

    We have previously reported that immunization with GRA2 antigen of Toxoplasma gondii induces protective immunity in CBA/J (H2k) and BALB/c mice (H2d). We aimed to examine whether immunization of a distinct strain of rodent with recombinant dense granule antigens (GRA2) combined with monophosphorryl lipid A (MPL) adjuvant elicits protective immune response against T. gondii. C57BL/6 (H2b haplotype) mice were immunized with GRA2, formulated in MPL adjuvant. Strong humoral response, predominantly of IgG1 subclass and cellular response, IFN-γ, was detected at three weeks post immunization. Mice immunized with GRA2 had significantly (p < 0.01) fewer brain cysts than those in the adjuvant group, upon challenge infection. Despite the production of a strong antibody response, IFN-γ production and brain cyst reduction were not significant when the immunized mice were infected four months after the immunization. We can conclude that GRA2 immunization partially protects against T. gondii infection in C57BL/6 mice, though the potency and longevity of this antigen as a standalone vaccine may vary in distinct genetic backgrounds. This observation further emphasizes the utility of GRA2 for incorporation into a multi-antigenic vaccine against T. gondii.

  3. Immune sensitization against epidermal antigens in polymorphous light eruption

    International Nuclear Information System (INIS)

    Gonzalez-Amaro, R.; Baranda, L.; Salazar-Gonzalez, J.F.; Abud-Mendoza, C.; Moncada, B.

    1991-01-01

    To get further insight into the pathogenesis of polymorphous light eruption, we studied nine patients with polymorphous light eruption and six healthy persons. Two skin biopsy specimens were obtained from each person, one from previously ultraviolet light-irradiated skin and another one from unirradiated skin. An epidermal cell suspension, skin homogenate, or both were prepared from each specimen. Autologous cultures were made with peripheral blood mononuclear cells combined with irradiated or unirradiated skin homogenate and peripheral blood mononuclear cells combined with irradiated or unirradiated epidermal cell suspension. Cell proliferation was assessed by 3H-thymidine incorporation assay. The response of peripheral blood mononuclear cells to unirradiated epidermal cells or unirradiated skin homogenate was similar in both patients and controls. However, peripheral blood mononuclear cells from patients with polymorphous light eruption showed a significantly increased proliferative response to both irradiated epidermal cells and irradiated skin homogenate. Our results indicate that ultraviolet light increases the stimulatory capability of polymorphous light eruption epidermal cells in a unidirectional mixed culture with autologous peripheral blood mononuclear cells. This suggests that an immune sensitization against autologous ultraviolet light-modified skin antigens occurs in polymorphous light eruption

  4. Proteasomal targeting and minigene repetition improve cell-surface presentation of a transfected, modified melanoma tumour antigen

    DEFF Research Database (Denmark)

    Rasmussen, A B; Zocca, M-B; Bonefeld, C M

    2004-01-01

    Melanoma antigen recognized by T cell 1 (MART-1) is regarded as a candidate peptide for vaccination against malignant melanoma, and it is of importance to develop strategies to improve the vaccine-elicited T-cell activation towards MART-1. T-cell activation is, among other determinants, dependent...... on the density of specific major histocompatibility complex-peptide complexes on the surface of the antigen-presenting cell. In this study, we explored the cell-surface presentation of a substituted MART-1 peptide encoded by transfected minigenes. We investigated the potential of proteasomal targeting compared...... to non-proteasomal targeting of the epitope to increase its cell-surface presentation. Furthermore, we explored the potential of incorporating multiple minigenes instead of one to increase cell-surface presentation. We show that both proteasomal targeting and repetition of the minigene increase cell...

  5. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells.

    Directory of Open Access Journals (Sweden)

    Yukiko Kiniwa

    Full Text Available Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8(+ T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4(+ T helper (Th cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4(+ T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1 as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4(+ Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4(+ T cell-mediated immunotherapy in melanoma.

  6. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells.

    Science.gov (United States)

    Kiniwa, Yukiko; Li, Jiang; Wang, Mingjun; Sun, Chuang; Lee, Jeffrey E; Wang, Rong-Fu; Wang, Helen Y

    2015-01-01

    Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8(+) T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4(+) T helper (Th) cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4(+) T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1) as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4(+) Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4(+) T cell-mediated immunotherapy in melanoma.

  7. Next-generation detection of antigen-responsive T cells using DNA barcode-labeled peptidemajor histocompatibility complex I multimers

    DEFF Research Database (Denmark)

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

    2016-01-01

    diversity of T cell recognition in humans. Consequently it has been impossible to comprehensively analyze T cell responsiveness in cancer, infectious and autoimmune diseases. We present and validate a novel technology that enables parallel detection of numerous different peptide-MHC responsive T cells...... with combinatorial encoding of fluorescent-labeled MHC multimers. Finally, we have demonstrated that this technology can be applied for multiplex T cell detection both in limited biological samples, such as uncultured tumor material, and for simultaneous assessment of target recognition and functional capability...... of T cells. This technology enables true high-throughput detection of antigen-responsive T cells and will advance our understanding of immune recognition from model antigens to genomewide immune assessments on a personalized basis....

  8. HUMORAL IMMUNE-RESPONSE TO 2,4-DINITROPHENYL KEYHOLE LIMPET HEMOCYANIN IN ANTIGEN-FREE, GERM-FREE AND CONVENTIONAL BALB/C MICE

    NARCIS (Netherlands)

    BOS, NA; PLOPLIS, VA

    The B cell immune response to 2,4-dinitrophenyl (DNP) keyhole limpet hemocyanin was compared in antigen-free, germ-free and conventional BALB/c mice. The numbers of total and of DNP-specific IgM-, IgG- and IgA-secreting cells in the spleen were determined by enzyme-linked immunosorbent plaque assays

  9. Immunogenic Targets for Specific Immunotherapy in Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    2012-01-01

    Full Text Available Multiple myeloma remains an incurable disease although the prognosis has been improved by novel therapeutics and agents recently. Relapse occurs in the majority of patients and becomes fatal finally. Immunotherapy might be a powerful intervention to maintain a long-lasting control of minimal residual disease or to even eradicate disseminated tumor cells. Several tumor-associated antigens have been identified in patients with multiple myeloma. These antigens are expressed in a tumor-specific or tumor-restricted pattern, are able to elicit immune response, and thus could serve as targets for immunotherapy. This review discusses immunogenic antigens with therapeutic potential for multiple myeloma.

  10. Global and local targeted immunization in networks with community structure

    International Nuclear Information System (INIS)

    Yan, Shu; Tang, Shaoting; Pei, Sen; Zheng, Zhiming; Fang, Wenyi

    2015-01-01

    Immunization plays an important role in the field of epidemic spreading in complex networks. In previous studies, targeted immunization has been proved to be an effective strategy. However, when extended to networks with community structure, it is unknown whether the superior strategy is to vaccinate the nodes who have the most connections in the entire network (global strategy), or those in the original community where epidemic starts to spread (local strategy). In this work, by using both analytic approaches and simulations, we observe that the answer depends on the closeness between communities. If communities are tied closely, the global strategy is superior to the local strategy. Otherwise, the local targeted immunization is advantageous. The existence of a transitional value of closeness implies that we should adopt different strategies. Furthermore, we extend our investigation from two-community networks to multi-community networks. We consider the mode of community connection and the location of community where epidemic starts to spread. Both simulation results and theoretical predictions show that local strategy is a better option for immunization in most cases. But if the epidemic begins from a core community, global strategy is superior in some cases. (paper)

  11. Immune modulation by genetic modification of dendritic cells with lentiviral vectors.

    Science.gov (United States)

    Liechtenstein, Therese; Perez-Janices, Noemi; Bricogne, Christopher; Lanna, Alessio; Dufait, Inès; Goyvaerts, Cleo; Laranga, Roberta; Padella, Antonella; Arce, Frederick; Baratchian, Mehdi; Ramirez, Natalia; Lopez, Natalia; Kochan, Grazyna; Blanco-Luquin, Idoia; Guerrero-Setas, David; Breckpot, Karine; Escors, David

    2013-09-01

    Our work over the past eight years has focused on the use of HIV-1 lentiviral vectors (lentivectors) for the genetic modification of dendritic cells (DCs) to control their functions in immune modulation. DCs are key professional antigen presenting cells which regulate the activity of most effector immune cells, including T, B and NK cells. Their genetic modification provides the means for the development of targeted therapies towards cancer and autoimmune disease. We have been modulating with lentivectors the activity of intracellular signalling pathways and co-stimulation during antigen presentation to T cells, to fine-tune the type and strength of the immune response. In the course of our research, we have found unexpected results such as the surprising immunosuppressive role of anti-viral signalling pathways, and the close link between negative co-stimulation in the immunological synapse and T cell receptor trafficking. Here we review our major findings and put them into context with other published work. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Induction of cell-mediated immunity against B16-BL6 melanoma in mice vaccinated with cells modified by hydrostatic pressure and chemical crosslinking.

    Science.gov (United States)

    Eisenthal, A; Ramakrishna, V; Skornick, Y; Shinitzky, M

    1993-05-01

    In the preceding paper we have demonstrated an increase in presentation of both major histocompatibility complex antigens (MHC) and a tumor-associated antigen of the weakly immunogenic B16 melanoma by a straight-forward technique. The method consists in modulating the tumor cell membrane by hydrostatic pressure and simultaneous chemical crosslinking of the cell-surface proteins. In B16-BL6 melanoma, the induced antigenic modulation was found to persist for over 48 h, which permitted the evaluation of the ability of modified B16-BL6 cells to induce immunity against unmodified B16-BL6 cells. In the present study, we have shown that a significant systemic immunity was induced only in mice that were immunized with modified B16-BL6 melanoma cells, whereas immunization with unmodified B16-BL6 cells had only a marginal effect when compared to the results in control sham-immunized mice. The induced immunity was specific since a single immunization affected the growth of B16-BL6 tumors but had no effect on MCA 106, an antigenically unrelated tumor. The addition of interleukin-2 to the immunization regimen had no effect on the antitumor responses induced by the modified B16-BL6 cells. The cell-mediated immunity conferred by immunization with treated B16-BL6 cells was confirmed in experiments in vitro where splenocytes from immunized mice could be sensitized to proliferate by the presence of B16-BL6 cells. In addition, the altered antigenicity of these melanoma cells appeared to correlate with their increased susceptibility to specific effectors. Thus, 51Cr-labeled B16-BL6 target cells, modified by pressure and crosslinking, in comparison to control labeled target cells, were lysed in much greater numbers by effectors such as lymphokine-activated killer cells and allogeneic cytotoxic lymphocytes (anti-H-2b), while such cells remained resistant to lysis by natural killer cells. Our findings indicate that the physical and chemical modifications of the tumor cells that are

  13. Th2-related immune responses by the Brucella abortus cellular antigens, malate dehydrogenase, elongation factor, and arginase.

    Science.gov (United States)

    Im, Young Bin; Shim, Soojin; Park, Woo Bin; Kim, Suk; Yoo, Han Sang

    2017-09-01

    Brucellosis is an important zoonotic disease caused by Brucella species. The disease is difficult to control due to the intracellular survival of the bacterium and the lack of precise understanding of pathogenesis. Despite of continuous researches on the pathogenesis of Brucella spp. infection, there is still question on the pathogenesis, especially earlier immune response in the bacterial infection. Malate dehydrogenase (MDH), elongation factor (Tsf), and arginase (RocF), which showed serological reactivity, were purified after gene cloning, and their immune modulating activities were then analyzed in a murine model. Cytokine production profiles were investigated by stimulating RAW 264.7 cells and naïve splenocytes with the three recombinant proteins. Also, immune responses were analyzed by ELISA and an ELIspot assay after immunizing mice with the three proteins. Only TNF-α was produced in stimulated RAW 264.7 cells, whereas Th1-related cytokines, IFN-γ and IL-2, were induced in naïve splenocytes. In contrast, Th2-type immune response was more strongly induced in antigen-secreting cells in the splenocytes obtained 28 days after immunizing mice with the three proteins, as were IgM and IgG. The induction of Th2-related antibody, IgG1, was higher than the Th1-related antibody, IgG2a, in immunized mice. These results suggest that the three proteins strongly induce Th2-type immune response in vivo, even though Th1-related cytokines were produced in vitro. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. HIV-1 Adaptation to Antigen Processing Results in Population-Level Immune Evasion and Affects Subtype Diversification

    DEFF Research Database (Denmark)

    Tenzer, Stefan; Crawford, Hayley; Pymm, Phillip

    2014-01-01

    these regions encode epitopes presented by ~30 more common HLA variants. By combining epitope processing and computational analyses of the two HIV subtypes responsible for ~60% of worldwide infections, we identified a hitherto unrecognized adaptation to the antigen-processing machinery through substitutions...... of intrapatient adaptations, is predictable, facilitates viral subtype diversification, and increases global HIV diversity. Because low epitope abundance is associated with infrequent and weak T cell responses, this most likely results in both population-level immune evasion and inadequate responses in most...

  15. The Mycobacterium tuberculosis cell-surface glycoprotein apa as a potential adhesin to colonize target cells via the innate immune system pulmonary C-type lectin surfactant protein A.

    Science.gov (United States)

    Ragas, Aude; Roussel, Lucie; Puzo, Germain; Rivière, Michel

    2007-02-23

    Tuberculosis is still a major health problem, and understanding the mechanism by which Mycobacterium tuberculosis (Mtb) invades and colonizes its host target cells remains an important issue for the control of infection. The innate immune system C-type lectins (C-TLs), including the human pulmonary surfactant protein A (PSP-A), have been recently identified as determinant players in the early recognition of the invading pathogen and in mounting the host defense response. Although the antigenic lipoglycan mannosylated lipoarabinomannan is currently considered to be the major C-TL target on the mycobacterial surface, the recognition by some C-TLs of the only mycobacterial species composing the "Mtb complex" indicates that mannosylated lipoarabinomannan cannot account alone for this specificity. Thus, we searched for the mycobacterial molecules targeted by human PSP-A, focusing our attention on the Mtb surface glycoproteins. We developed an original functional proteomic approach based on a lectin blot assay using crude human bronchoalveolar lavage fluid as a source of physiological PSP-A. Combined with selective cell-surface protein extraction and mass spectrometry peptide mapping, this strategy allowed us to identify the Apa (alanine- and proline-rich antigenic) glycoprotein as new potential target for PSP-A. This result was supported by direct binding of PSP-A to purified Apa. Moreover, EDTA addition or deglycosylation of purified Apa samples completely abolished the interaction, demonstrating that the interaction is calcium- and mannose-dependent, as expected. Finally, we provide convincing evidence that Apa, formerly considered as mainly secreted, is associated with the cell wall for a sufficiently long time to aid in the attachment of PSP-A. Because, to date, Apa seems to be restricted to the Mtb complex strains, we propose that it may account for the selective recognition of those strains by PSP-A and other immune system C-TLs containing homologous functional

  16. Shaping the CD4+ memory immune response against tuberculosis: the role of antigen persistence, location and multi-functionality.

    Science.gov (United States)

    Ancelet, Lindsay; Kirman, Joanna

    2012-02-01

    Abstract Effective vaccination against intracellular pathogens, such as tuberculosis (TB), relies on the generation and maintenance of CD4 memory T cells. An incomplete understanding of the memory immune response has hindered the rational design of a new, more effective TB vaccine. This review discusses how the persistence of antigen, the location of memory cells, and their multifunctional ability shape the CD4 memory T cell response against TB.

  17. Hepatitis B core protein as a therapeutic target.

    Science.gov (United States)

    Mak, Lung-Yi; Wong, Danny Ka-Ho; Seto, Wai-Kay; Lai, Ching-Lung; Yuen, Man Fung

    2017-12-01

    Chronic hepatitis B virus (HBV) infection is difficult to cure, due to the presence of covalently-closed-circular DNA and virus-mediated blunting of host immune response. Existing therapies with nucleos(t)ide analogue or pegylated-interferon are not sufficient to achieve a high rate of HBV surface antigen seroclearance, a more desirable treatment outcome. Novel therapeutic agents targeting alternative viral replication steps are being developed. In this review, we will discuss the hepatitis B core antigen (HBcAg) as a therapeutic target. Areas covered: The basic structure and fundamental functions of HBcAg including nucleocapsid assembly, pre-genomic RNA encapsidation, reverse transcription, virion formation, cccDNA amplification, immune response regulation, and HBx protein interaction will be reviewed. Most of these are identified as therapeutic targets and tested in in vitro and in vivo studies, although clinical trials are scanty. Among the different components, the core protein allosteric modulators (CpAM) have been most widely investigated and appear promising in clinical trials. Expert opinion: The multiple and essential functions of HBcAg for HBV life cycle are important and attractive targets for HBV therapeutic interventions. Controlled trials involving CpAM are awaited. Apart from CpAM, drugs directed against different functions of HBcAg may be further explored to maximize the chance of cure.

  18. T cell immunity

    OpenAIRE

    Emel Bülbül Başkan

    2013-01-01

    Since birth, our immune system is constantly bombarded with self-antigens and foreign pathogens. To stay healthy, complex immune strategies have evolved in our immune system to maintain self-tolerance and to defend against foreign pathogens. Effector T cells are the key players in steering the immune responses to execute immune functions. While effector T cells were initially identified to be immune promoting, recent studies unraveled negative regulatory functions of effector T cells...

  19. Application of 125I-labelled soluble proteins in the histoautoradiographic detection of antigen and antibodies in the spleen of rabbits during primary immune response

    International Nuclear Information System (INIS)

    Rodak, L.

    1975-01-01

    An autoradiographic method for detecting soluble antigen (chicken serum albumin, CSA) and specific antibodies in the spleen of rabbits during a primary immune response is described. The method consists of incubating sections from the spleen with 125 I-labelled IgG 2 anti CSA (for demonstration of antigen) or with 125 I-labelled antigen (for demonstration of specific antibodies). This treatment of histological sections combines the advantages and principles of the immunofluorescence technique with the possibility of evaluating the exact localization of the proteins by light microscopy in preparations stained with haematoxylin or methyl green-pyronin. The sensitivity of detection is very high: both antigen and antibodies could be demonstrated in the spleen follicles for as long as 42 days after the primary intravenous injection

  20. The link between CD8⁺ T-cell antigen-sensitivity and HIV-suppressive capacity depends on HLA restriction, target epitope and viral isolate.

    Science.gov (United States)

    Lissina, Anna; Fastenackels, Solène; Inglesias, Maria C; Ladell, Kristin; McLaren, James E; Briceño, Olivia; Gostick, Emma; Papagno, Laura; Autran, Brigitte; Sauce, Delphine; Price, David A; Saez-Cirion, Asier; Appay, Victor

    2014-02-20

    Although it is established that CD8 T-cell immunity is critical for the control of HIV replication in vivo, the key factors that determine antiviral efficacy are yet to be fully elucidated. Antigen-sensitivity and T-cell receptor (TCR) avidity have been identified as potential determinants of CD8⁺ T-cell efficacy. However, there is no general consensus in this regard because the relationship between these parameters and the control of HIV infection has been established primarily in the context of immunodominant CD8⁺ T-cell responses against the Gag₂₆₃₋₂₇₂ KK10 epitope restricted by human leukocyte antigen (HLA)-B27. To investigate the relationship between antigen-sensitivity, TCR avidity and HIV-suppressive capacity in vitro across epitope specificities and HLA class I restriction elements, we used a variety of techniques to study CD8⁺ T-cell clones specific for Nef₇₃₋₈₂ QK10 and Gag₂₀₋₂₉ RY10, both restricted by HLA-A3, alongside CD8⁺ T-cell clones specific for Gag₂₆₃₋₂₇₂ KK10. For each targeted epitope, the linked parameters of antigen-sensitivity and TCR avidity correlated directly with antiviral efficacy. However, marked differences in HIV-suppressive capacity were observed between epitope specificities, HLA class I restriction elements and viral isolates. Collectively, these data emphasize the central role of the TCR as a determinant of CD8⁺ T-cell efficacy and demonstrate that the complexities of antigen recognition across epitope and HLA class I boundaries can confound simple relationships between TCR engagement and HIV suppression.

  1. IFNG-mediated immune responses enhance autophagy against Mycobacterium tuberculosis antigens in patients with active tuberculosis

    Science.gov (United States)

    Rovetta, Ana I; Peña, Delfina; Hernández Del Pino, Rodrigo E; Recalde, Gabriela M; Pellegrini, Joaquín; Bigi, Fabiana; Musella, Rosa M; Palmero, Domingo J; Gutierrez, Marisa; Colombo, María I; García, Verónica E

    2015-01-01

    Protective immunity against Mycobacterium tuberculosis (Mtb) requires IFNG. Besides, IFNG-mediated induction of autophagy suppresses survival of virulent Mtb in macrophage cell lines. We investigated the contribution of autophagy to the defense against Mtb antigen (Mtb-Ag) in cells from tuberculosis patients and healthy donors (HD). Patients were classified as high responders (HR) if their T cells produced significant IFNG against Mtb-Ag; and low responders (LR) when patients showed weak or no T cell responses to Mtb-Ag. The highest autophagy levels were detected in HD cells whereas the lowest quantities were observed in LR patients. Interestingly, upon Mtb-Ag stimulation, we detected a positive correlation between IFNG and MAP1LC3B-II/LC3-II levels. Actually, blockage of Mtb-Ag-induced IFNG markedly reduced autophagy in HR patients whereas addition of limited amounts of IFNG significantly increased autophagy in LR patients. Therefore, autophagy collaborates with human immune responses against Mtb in close association with specific IFNG secreted against the pathogen. PMID:25426782

  2. Intravenous IgA complexed with antigen reduces primary antibody response to the antigen and anaphylaxis upon antigen re-exposure by inhibiting Th1 and Th2 activation in mice.

    Science.gov (United States)

    Yamaki, Kouya; Miyatake, Kenji; Nakashima, Takayuki; Morioka, Ayumi; Yamamoto, Midori; Ishibashi, Yuki; Ito, Ayaka; Kuranishi, Ayu; Yoshino, Shin

    2014-10-01

    Serum IgG, IgE and IgM have been shown to enhance the primary antibody responses upon exposure to the soluble antigens recognized by those antibodies. However, how IgA affects these responses remains unknown. We investigated the effects of intravenously administered monoclonal IgA on the immune responses in mice. DBA/1J mice were immunized with ovalbumin in the presence or absence of anti-ovalbumin monoclonal IgA. The Th1 and Th2 immune responses to ovalbumin and the anaphylaxis induced by re-exposure to ovalbumin were measured. IgA complexed with antigen attenuated the primary antibody responses to the antigen in mice, in contrast to IgG2b and IgE. The primary antibody responses, i.e. the de novo synthesis of anti-ovalbumin IgG2a, IgG1 and IgE in the serum, and the subsequent anaphylaxis induced with re-exposure to ovalbumin were reduced by the co-injection of anti-ovalbumin monoclonal IgA at ovalbumin immunization. The Th1, Th2 and Tr1 cytokines interferon-γ, interleukin-4 and interleukin-10, respectively, released from ovalbumin-restimulated cultured splenocytes collected from allergic mice were also reduced by the treatment. The induction of interferon-γ and interleukin-4 secretion by splenocytes from ovalbumin-immunized mice stimulated in vitro with ovalbumin was also significantly reduced by the antigen complexed with anti-ovalbumin IgA. These data suggest that the direct inhibition of Th1 and Th2 activation by anti-ovalbumin monoclonal IgA participates in the inhibition of the primary antibody responses. IgA plays important immunosuppressive roles under physiological and pathological conditions and is a promising candidate drug for the treatment of immune disorders.

  3. Demonstration of tumor-associated antigens in dogs

    International Nuclear Information System (INIS)

    Warren, R.P.; Tsoi, M.S.; Henderson, B.H.; Weiden, P.L.; Storb, R.

    1975-01-01

    Procedures for the 51 Cr release assay using labeled L cells or lymphocytes and the indirect leukocyte migration test are described. These assays appear capable of detecting cellular immunity against tumor associated antigens in dogs. In 8 of 14 instances, lymphocyte-mediated cytotoxicity to autochthonous L cells was found as measured by 51 Cr release, and lymphocytes from 12 of 24 dogs produced the migration inhibition factor (MIF) when cultured with autochthonous tumor cells. Chromium-51 release occurred with 4 h of exposure of effector cells to target cells, suggesting that the immunity detected in the tumor dogs against their tumors is also present in vivo. With the leukocyte migration test, however, consistent MIF production was achieved only after 3 to 6 days in culture, suggesting that in vitro sensitization may result in increased MIF production

  4. Idiotypes as immunogens: facing the challenge of inducing strong therapeutic immune responses against the variable region of immunoglobulins

    International Nuclear Information System (INIS)

    López-Requena, Alejandro; Burrone, Oscar R.; Cesco-Gaspere, Michela

    2012-01-01

    Idiotype (Id)-based immunotherapy has been exploited as cancer treatment option. Conceived as therapy for malignancies bearing idiotypic antigens, it has been also extended to solid tumors because of the capacity of anti-idiotypic antibodies to mimic Id-unrelated antigens. In both these two settings, efforts are being made to overcome the poor immune responsiveness often experienced when using self immunoglobulins as immunogens. Despite bearing a unique gene combination, and thus particular epitopes, it is normally difficult to stimulate the immune response against antibody variable regions. Different strategies are currently used to strengthen Id immunogenicity, such as concomitant use of immune-stimulating molecules, design of Id-containing immunogenic recombinant proteins, specific targeting of relevant immune cells, and genetic immunization. This review focuses on the role of anti-Id vaccination in cancer management and on the current developments used to foster anti-idiotypic B and T cell responses.

  5. Idiotypes as immunogens: facing the challenge of inducing strong therapeutic immune responses against the variable region of immunoglobulins

    Energy Technology Data Exchange (ETDEWEB)

    López-Requena, Alejandro [Molecular Immunology Group, International Centre for Genetic Engineering and Biotechnology, Trieste (Italy); Immunobiology Division, Center of Molecular Immunology, Havana (Cuba); Bioengineering Research Institute, Biotech Pharmaceutical Co., Ltd, Beijing (China); Burrone, Oscar R.; Cesco-Gaspere, Michela, E-mail: cescogaspere@gmail.com [Molecular Immunology Group, International Centre for Genetic Engineering and Biotechnology, Trieste (Italy)

    2012-11-09

    Idiotype (Id)-based immunotherapy has been exploited as cancer treatment option. Conceived as therapy for malignancies bearing idiotypic antigens, it has been also extended to solid tumors because of the capacity of anti-idiotypic antibodies to mimic Id-unrelated antigens. In both these two settings, efforts are being made to overcome the poor immune responsiveness often experienced when using self immunoglobulins as immunogens. Despite bearing a unique gene combination, and thus particular epitopes, it is normally difficult to stimulate the immune response against antibody variable regions. Different strategies are currently used to strengthen Id immunogenicity, such as concomitant use of immune-stimulating molecules, design of Id-containing immunogenic recombinant proteins, specific targeting of relevant immune cells, and genetic immunization. This review focuses on the role of anti-Id vaccination in cancer management and on the current developments used to foster anti-idiotypic B and T cell responses.

  6. Humoral and In Vivo Cellular Immunity against the Raw Insect-Derived Recombinant Leishmania infantum Antigens KMPII, TRYP, LACK, and papLe22 in Dogs from an Endemic Area

    Science.gov (United States)

    Todolí, Felicitat; Solano-Gallego, Laia; de Juan, Rafael; Morell, Pere; del Carmen Núñez, Maria; Lasa, Rodrigo; Gómez-Sebastián, Silvia; Escribano, José M.; Alberola, Jordi; Rodríguez-Cortés, Alhelí

    2010-01-01

    Leishmania infantum causes visceral leishmaniasis, a severe zoonotic and systemic disease that is fatal if left untreated. Identification of the antigens involved in Leishmania-specific protective immune response is a research priority for the development of effective control measures. For this purpose, we evaluated, in 27 dogs from an enzootic zone, specific humoral and cellular immune response by delayed-type hypersensitivity (DTH) skin test both against total L. infantum antigen and the raw Trichoplusia ni insect-derived kinetoplastid membrane protein-11 (rKMPII), tryparedoxin peroxidase (rTRYP), Leishmania homologue of receptors for activated C kinase (rLACK), and 22-kDa potentially aggravating protein of Leishmania (rpapLe22) antigens from this parasite. rTRYP induced the highest number of positive DTH responses (55% of leishmanin skin test [LST]-positive dogs), showing that TRYP antigen is an important T cell immunogen, and it could be a promising vaccine candidate against this disease. When TRYP-DTH and KMPII-DTH tests were evaluated in parallel, 82% of LST-positive dogs were detected, suggesting that both antigens could be considered as components of a standardized DTH immunodiagnostic tool for dogs. PMID:21118936

  7. Development of A Chimeric Antigen Receptor Targeting C-Type Lectin-Like Molecule-1 for Human Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Eduardo Laborda

    2017-10-01

    Full Text Available The treatment of patients with acute myeloid leukemia (AML with targeted immunotherapy is challenged by the heterogeneity of the disease and a lack of tumor-exclusive antigens. Conventional immunotherapy targets for AML such as CD33 and CD123 have been proposed as targets for chimeric antigen receptor (CAR-engineered T-cells (CAR-T-cells, a therapy that has been highly successful in the treatment of B-cell leukemia and lymphoma. However, CD33 and CD123 are present on hematopoietic stem cells, and targeting with CAR-T-cells has the potential to elicit long-term myelosuppression. C-type lectin-like molecule-1 (CLL1 or CLEC12A is a myeloid lineage antigen that is expressed by malignant cells in more than 90% of AML patients. CLL1 is not expressed by healthy Hematopoietic Stem Cells (HSCs, and is therefore a promising target for CAR-T-cell therapy. Here, we describe the development and optimization of an anti-CLL1 CAR-T-cell with potent activity on both AML cell lines and primary patient-derived AML blasts in vitro while sparing healthy HSCs. Furthermore, in a disseminated mouse xenograft model using the CLL1-positive HL60 cell line, these CAR-T-cells completely eradicated tumor, thus supporting CLL1 as a promising target for CAR-T-cells to treat AML while limiting myelosuppressive toxicity.

  8. The influence of concentration of inactivated Edwardsiella tarda bacterin and immersion time on antigen uptake and expression of immune-related genes in Japanese flounder (Paralichthys olivaceus).

    Science.gov (United States)

    Du, Yang; Tang, Xiaoqian; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

    2017-02-01

    Our previous work has demonstrated that the immune response of Japanese flounder was associated with the concentration of formalin-inactivated Edwardsiella tarda and immersion time. In order to further investigate the influence of immersion vaccine dose and bath time on the antigen uptake, formalin-killed Edwardsiella tarda bacterin was prepared and adjusted to four concentrations (10 9 , 10 8 , 10 7 , 10 6  cfu ml -1 ) for 30, 60 and 90 min immersion in Japanese flounder model, respectively. Absolute quantitative real-time PCR was employed to examine the bacterin uptake in gill, skin, spleen and kidney at 3 and 6 h post vaccination. The results showed that the antigen uptaken in gills and skin were significant higher than spleen and kidney, and the antigen amounts in gill and skin both declined from 3 to 6 h, whereas the antigen amounts in spleen and kidney gradually increased. Significant higher antigen amounts were detected in 10 9 -30, 10 9 -60, 10 8 -60, 10 8 -90 and 10 8 -90 groups than other groups (P immersion with formalin-inactivated E. tarda, especially under 10 8 -60 min condition could efficiently enhance the antigen uptake and the expression of immune-related genes, which provided evidences for an enhanced vaccination effects under an optimized combination of vaccine dose and immersion time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Cancer Immunotherapy and the Immune Response in Hodgkin Lymphoma

    Directory of Open Access Journals (Sweden)

    Christoph Renner

    2018-06-01

    Full Text Available Patients with classical Hodgkin lymphoma (cHL have an impaired cellular immune response as indicated by an anergic reaction against standard recall antigens and a diminished rejection reaction of allogeneic skin transplant. This clinical observation can be linked to the histopathological feature of cHL since the typical pattern of a cHL manifestation is characterized by sparse large CD30+ tumor-infiltrating Hodgkin–Reed–Sternberg (HRS cells that are surrounded by a dense inflammatory immune microenvironment with mixed cellularity. Despite this extensive polymorphous inflammatory infiltrate, there is only a poor antitumor immune response seen to the neoplastic HRS cells. This is primarily mediated by a high expression of PD-L1 and PD-L2 ligands on the HRS cell surface which in turn antagonizes the activity of programmed death-1 (PD-1 antigen-positive T cells. PD-L1/L2 overexpression is caused by gene amplification at the 9p24.1 locus and/or latent Epstein–Barr virus infection present in around 40% of cHL cases. The blockade of the PD-L1/L2–PD-1 pathway by monoclonal antibodies can restore local T cell activity and leads to impressive tumor responses, some of which are long lasting and eventually curative. Another feature of HRS cells is the high CD30 antigen expression. Monoclonal antibody technology allowed for the successful development of CD30-specific immunotoxins, bispecific antibodies, and reprogrammed autologous T cells with the first one already approved for the treatment of high risk or relapsed cHL. Altogether, the discovery of the described pathomechanism of immune suppression and the identification of preferential target antigens has rendered cHL to be a prime subject for the successful development of new immunotherapeutic approaches.

  10. 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...

  11. Reinfection immunity in schistosomiasis

    International Nuclear Information System (INIS)

    Kamiya, Haruo

    1987-01-01

    Schistosomiasis is one of the most important parasitic diseases in the world, especially in endemic areas of developing countries. This situation has prompted parasitologist to attempt intensive researches on immune mechanisms, especially those of reinfection immunity associated with eliminating challenge infection. The current knowledge of reinfection immunity against Schistosoma spp. infection was therefore reviewed briefly and discussed with special reference to our data on protective immune responses induced by radiation-attenuated cercarial infection. A recently developed technique of compressed organ autoradiography (COA) has contributed to assessing parasite attrition in immune animals following challenge infection. Our study using COA has demonstrated that major attrition of schistosomula from challenge infection occurs in the skin of CBA/Ca mice vaccinated with 20 Krad gamma radiation-attenuated cercariae of S. mansoni, while in both lungs and liver of similarly vaccinated guinea pig model. Furthermore, gamma-irradiation to cercariae affected their migration potential and surface-antigen profiles. The immunizing stimuli of gamma radiation-attenuated cercariae profoundly affected the expression of responsiveness in vaccinated animals. The change in antigenic profiles and migration potential of those vaccinating population was discussed in relation to the kinetics of reinfection immunity induced in vaccinated amimal models. These works might provide a base line data to develop a practical vaccine for schistosomiasis using defined antigens. It must be emphasized that these vaccines could serve as a practical prophylactic measure for schistosomiasis in the endemic areas, even if the vaccines fail to induce sterilizing immunity. (author). 141 refs

  12. Stromal infrastructure of the lymph node and coordination of immunity.

    Science.gov (United States)

    Chang, Jonathan E; Turley, Shannon J

    2015-01-01

    The initiation of adaptive immune responses depends upon the careful maneuvering of lymphocytes and antigen into and within strategically placed lymph nodes (LNs). Non-hematopoietic stromal cells form the cellular infrastructure that directs this process. Once regarded as merely structural features of lymphoid tissues, these cells are now appreciated as essential regulators of immune cell trafficking, fluid flow, and LN homeostasis. Recent advances in the identification and in vivo targeting of specific stromal populations have resulted in striking new insights to the function of stromal cells and reveal a level of complexity previously unrealized. We discuss here recent discoveries that highlight the pivotal role that stromal cells play in orchestrating immune cell homeostasis and adaptive immunity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Isotope-based immunological techniques. Their use in assessment of immune competence and the study of immune responses to pathogens

    International Nuclear Information System (INIS)

    Duffus, W.P.H.

    1984-01-01

    The influence of isotope-based techniques on both assessment of immune competence and immune response to pathogens is discussed. Immunodeficiencies acquired as a result of factors like malnutrition and concomitant disease can severely affect not only attempts to intensify and improve production but also successful immune response against important vaccines such as rinderpest and foot-and-mouth disease. Isotope-based techniques, with their accuracy, speed and small sample volume, are ideally suited for assessing immunocompetence. One of the main drawbacks remains antigen purity, an area where research should now be concentrated. Lymphocyte transformation is widely used to assess cell-mediated immuno-competence but techniques to assess biological functions such as phagocytosis and cell-mediated cytotoxicity could more usefully reflect immune status. These latter techniques utilize isotopes such as 3 H, 14 C, 32 P and 125 I. Investigation of specific cell-mediated immune response often requires a labelled target. Suitable isotopes such as 51 Cr, 99 Tcsup(m), 75 Se and 3 H are compared for their capacity to label both mammalian and parasite targets. Suggestions are made on a number of areas of research that might usefully be encouraged and supported in order to improve applied veterinary immunology in tropical countries. (author)

  14. The Targeting of Indoleamine 2,3 Dioxygenase -Mediated Immune Escape in Cancer

    DEFF Research Database (Denmark)

    Iversen, Trine Zeeberg; Andersen, Mads Hald; Svane, Inge Marie

    2015-01-01

    The era of immunotherapies was unleashed in 2010 with the Food and Drug Administration (FDA) approval of the first therapeutic vaccine sipuleucel-T as a standard treatment for metastatic prostate cancer. Next, the first immune-activating anticytotoxic lymphocyte antigen-4 (CTLA-4) antibody...... investigation in metastatic melanoma (MM) and non-small-cell lung cancer (NSCLC), and impressive clinical results are anticipated. Despite these successes, only a fraction of patients become clinical responders to therapy. Thus, to improve the selection of patients likely to respond, scrutinizing different...

  15. Impact of aging on antigen presentation cell function of dendritic cells.

    Science.gov (United States)

    Wong, Christine; Goldstein, Daniel R

    2013-08-01

    Older people exhibit increased mortality to infections and cancer as compared to younger people, indicating that aging impairs immunity. Dendritic cells (DCs) are key for bridging the innate and adaptive arms of the immune system by priming antigen specific T cells. Discerning how aging impacts DC function to initiate adaptive immune responses is of great biomedical importance as this could lead to the development of novel therapeutics to enhance immunity with aging. This review details reports indicating that aging impairs the antigen presenting function of DCs but highlights other studies indicating preserved DC function with aging. How aging impacts antigen presentation by DCs is complex and without a clear unifying biological underpinning. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Purification of antibodies to bacterial antigens by an immunoadsorbent and a method to quantify their reaction with insoluble bacterial targets

    International Nuclear Information System (INIS)

    Mathews, H.L.; Minden, P.

    1979-01-01

    A combination of procedures was employed to develop a radioimmunoassay which quantified the binding of antibodies to antigens of either intact Propionibacterium acnes or to antigens of insoluble extracts derived from the bacteria. Reactive antibody populations were purified by use of bacterial immunoadsorbents which were prepared by coupling P. acnes to diethylaminoethyl cellulose. Binding of antibodies was detected with [ 125 I]staphylococcal protein A ([ 125 I]SpA) and optimal conditions for the assay defined by varying the amounts of antibodies, bacterial antigenic targets and [ 125 I]SpA. In antibody excess, 100% of available [ 125 I]SpA was bound by the target-antibody complexes. However, when antibody concentration was limiting, a linear relationship was demonstrated between per cent specific binding of[ 125 I]SpA and antibodies bound to bacterial targets. These results were achieved only with immunoadsorbent-purified antibody populations and not with hyperimmune sera or IgG. The radioimmunoassay detected subtle antigenic differences and similarities between P. acnes, P. acnes extracts and a variety of unrelated microorganisms. (Auth.)

  17. Chlorphenesin: an antigen-associated immunosuppressant.

    Science.gov (United States)

    Whang, H Y; Neter, E

    1970-07-01

    Chlorphenesin (3-p-chlorophenoxy-1,2-propanediol), when injected intravenously together with either of two common bacterial antigens, inhibits the antibody response of the rabbit. The antigens studied are those common to Enterobacteriaceae and to gram-positive bacteria. The immunosuppression is contingent upon incubation of chlorphenesin and antigen in vitro prior to administration, since separate injection of antigen and inhibitor or of mixtures without prior incubation yields undiminished antibody response. Chlorphenesin, as shown by hemagglutination-inhibition tests, does not alter the antigenic determinants, because antibody neutralization occurs in the presence or absence of the drug. The immunosuppressive effect is reversible, since precipitation of chlorphenesin at 4 C substantially restores immunogenicity. Animals immunized with antigen-drug mixtures, which fail to respond with significant antibody production, nonetheless are immunologically primed. It is concluded that chlorphenesin represents another example of antigen-associated immunosuppressants.

  18. Cross-immunity among allogeneic tumors in rats immunized with gamma-irradiated ascites tumors

    International Nuclear Information System (INIS)

    Sato, Tatsusuke; Suga, Michio; Kudo, Hajime; Waga, Takashi; Ogasawara, Masamichi

    1980-01-01

    Non-inbred rats of the Gifu strain were intraperitoneally challenged with Hirosaki sarcoma (Tetraploid type, 10 5 cells) after repeated immunization with gamma-irradiated (13,000 rads 60 Co) allogeneic non-viral tumors of ascites type (Tetraploid or diploid type of Hirosaki sarcoma, Usubuchi sarcoma or AH130). In rats immunized not only with the same tumor as the immunizing tumor but also with a different tumor, the growth of the challenge tumor was markedly inhibited as compared with the control in non-immunized rats. It is considered that these tumors retained common antigen(s) by the resistance to irradiation because of their form of ascites tumor. The marked cross-immunity in rats immunized with AH130 may be explained by the fact that gamma-irradiated AH130 cells were alive longer