36 research outputs found

    T- and B-cell responses to multivalent prime-boost DNA and viral vectored vaccine combinations against hepatitis C virus in non-human primates.

    Get PDF
    Immune responses against multiple epitopes are required for the prevention of hepatitis C virus (HCV) infection, and the progression to phase I trials of candidates may be guided by comparative immunogenicity studies in non-human primates. Four vectors, DNA, SFV, human serotype 5 adenovirus (HuAd5) and Modified Vaccinia Ankara (MVA) poxvirus, all expressing hepatitis C virus Core, E1, E2 and NS3, were combined in three prime-boost regimen, and their ability to elicit immune responses against HCV antigens in rhesus macaques was explored and compared. All combinations induced specific T-cell immune responses, including high IFN-γ production. The group immunized with the SFV+MVA regimen elicited higher E2-specific responses as compared with the two other modalities, while animals receiving HuAd5 injections elicited lower IL-4 responses as compared with those receiving MVA. The IFN-γ responses to NS3 were remarkably similar between groups. Only the adenovirus induced envelope-specific antibody responses, but these failed to show neutralizing activity. Therefore, the two novel regimens failed to induce superior responses as compared with already existing HCV vaccine candidates. Differences were found in response to envelope proteins, but the relevance of these remain uncertain given the surprisingly poor correlation with immunogenicity data in chimpanzees, underlining the difficulty to predict efficacy from immunology studies.This work was supported by European Union contract QLK2-CT-1999- 00356, by the Biomedical Primate Research Centre, The Netherlands, and by the Swedish Research Council. We are grateful to Alexander van den Berg for technical assistance with the ICS, to our colleagues from Animal Science Department for technical assistance and expert care of the macaques, to the participants of the European HCVacc Cluster who provided help and support, and to Thomas Darton (Oxford Vaccine Group, UK) for input and advice on the manuscript. Christine Rollier is an Oxford Martin fellow and a Jenner Insitute Investigator.This is the author accepted manuscript. The final version is available from Nature Publishing Group at https://doi.org/10.1038/gt.2016.55

    Qualitative differences in cellular immunogenicity elicited by hepatitis C virus T-Cell vaccines employing prime-boost regimens.

    Get PDF
    T-cell based vaccines have been considered as attractive candidates for prevention of hepatitis C virus (HCV) infections. In this study we compared the magnitude and phenotypic characteristics of CD8+ T-cells induced by three commonly used viral vectors, Adenovirus-5 (Ad5), Vaccinia virus (VV) and Modified Vaccinia Ankara (MVA) expressing the HCV NS3/4A protein. C57/BL6 mice were primed with DNA expressing NS3/4A and boosted with each of the viral vectors in individual groups of mice. We then tracked the vaccine-induced CD8+ T-cell responses using pentamer binding and cytokine production analysis. Overall, our data indicate that the memory cells induced by Ad5 were inferior to those induced by VV or MVA. We found that Ad5 boosting resulted in rapid expansion and significantly higher frequencies of NS3-specific T-cells compared to VV and MVA boosting. However, the functional profiles, assessed through analysis of the memory cell marker CD127 and the anti-apoptotic molecule Bcl-2 in the blood, spleen, and liver; and measurements of interferon-gamma, tumor necrosis factor-alpha, and interleukin-2 production indicated significantly lower frequencies of long-lived memory T-cells following Ad5 boosting compared to VV and MVA. This same set of analyses suggested that the memory cells induced following boosting with MVA were superior to those induced by both Ad5 and VV. This superiority of the MVA-induced CD8+ T-cells was confirmed following surrogate challenge of mice with a recombinant mouse herpes virus expressing the HCV NS3 protein. Higher levels of NS3-specific CD8+ T-cells displaying the functional markers CD69, Ki67 and Granzyme B were found in the spleens of mice boosted with MVA compared to VV and Ad5, both alone and in combination. These data suggest that MVA may be a more successful viral vector for induction of effective CD8+ T-cell responses against hepatitis C virus

    MONOCLONAL ANTIBODIES AND RECOMBINANT PROTEINS OF FILOVIRUSES: IMMUNOCHEMICAL PROPERTIES AND EVALUATION OF THEIR EFFICIENCY FOR IMMUNE DIAGNOSTICS OF MARBURG AND EBOLA VIRUSES

    No full text
    A panel of monoclonal antibodies (MAbs) against VP35, VP40 and NP viral proteins of Marburg and Ebola viruses, as well as recombinant VP35, VP40 and NP proteins were generated and tested for their capacity to specific immune reactions. Monoclonal antibodies to appropriate viral proteins effectively recognized the VP35, VP40 and NP recombinant proteins, thus allowing to develop a variant of a MAb-based ELISA analysis with different types of biotin-labeled MAbs, using these antibodies for capturing viral and recombinant antigens of Marburg and Ebola viruses. These techniques were able to detect viral and recombinant proteins in a concentration range between 1 and 150 ng/ml. We conclude that the recombinant VP35, VP40 and NP proteins of filoviruses, as well as MAbs against these viral proteins represent a promising tool for a new generation of immunodiagnostic kits and studying immunological features of filovirus infection

    Regulatory Concerns about Medical Device Manufacturing Using 3D Printing: Current State of the Issue

    Get PDF
    Custom-made implants, orthotics, orthoses, models for surgical planning and education, and much more are now created using 3D printers. In this article, the authors suiiunarized information on laws and regulations in the domain of legal support for 3D printing of medical devices in Russia and abroad. 3D printing is one of the promising avenues in developing new methods of treatment, so iiiunediate establishing of clear criteria for its legal regulation is necessary. As is, there are still many gaps in the legislative framework. The issues of the quality of 3D models, material standardization and manufacturing processes using 3D printing technologies remain unresolved. When using custom-made medical devices, respecting the rights of patients and preventing the use of prohibited or restricted materials are essential. Yet, legal barriers to this irmovative direction of medicine must be avoided

    Obtaining and Immunologic Characterization of Filoviruses Recombinant Proteins VP40 and NP

    No full text
    Full-size genes coding matrix proteins VP40 of Ebola virus (VE) and Marburg virus (VM) and nucleoprotein (NP) of VE were cloned. These genes expression in Escherichia coli and purification of their products by affinity chromatography using Ni-NTA agarose permitted to obtain full-size recombinant VP40 and NP proteins of filoviruses. Immunological studies showed the recombinant polypeptides to possess antigenic properties similar to those of the native viral proteins. These proteins can be used for constructing of experimental vaccines against filoviruses and improving immunodiagnostic tests against filoviral infections
    corecore