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  • American Society for Microbiology  (6)
  • Pitisuttithum, Punnee  (6)
  • 1
    Online-Ressource
    Online-Ressource
    Vaccine-Induced HIV-1 Envelope gp120 Constant Region 1-Specific Antibodies Expose a CD4-Inducible Epitope and Block the Interaction of HIV-1 gp140 with Galactosylceramide
    American Society for Microbiology ; 2014
    In:  Journal of Virology Vol. 88, No. 16 ( 2014-08-15), p. 9406-9417
    Details
    In: Journal of Virology, American Society for Microbiology, Vol. 88, No. 16 ( 2014-08-15), p. 9406-9417
    Kurzfassung: Mucosal epithelial cell surface galactosylceramide (Galcer) has been postulated to be a receptor for HIV-1 envelope (Env) interactions with mucosal epithelial cells. Disruption of the HIV-1 Env interaction with such alternate receptors could be one strategy to prevent HIV-1 entry through the mucosal barrier. To study antibody modulation of HIV-1 Env-Galcer interactions, we used Galcer-containing liposomes to assess whether natural- and vaccine-induced monoclonal antibodies can block HIV-1 Env binding to Galcer. HIV-1 Env gp140 proteins bound to Galcer liposomes with K d s (dissociation constants) in the nanomolar range. Several HIV-1 ALVAC/AIDSVAX vaccinee-derived monoclonal antibodies (MAbs) specific for the gp120 first constant (C1) region blocked Galcer binding of a transmitted/founder HIV-1 Env gp140. Among the C1-specific MAbs that showed Galcer blocking, the antibody-dependent cellular cytotoxicity-mediating CH38 IgG and its natural IgA isotype were the most potent blocking antibodies. C1-specific IgG monoclonal antibodies that blocked Env binding to Galcer induced upregulation of the gp120 CD4-inducible (CD4i) epitope bound by MAb 17B, demonstrating that a conformational change in gp120 may be required for Galcer blocking. However, the MAb 17B itself did not block Env-Galcer binding, suggesting that the C1 antibody-induced gp120 conformational changes resulted in alteration in a Galcer binding site distant from the CD4i 17B MAb binding site. IMPORTANCE Galactosyl ceramide, a glycosphingolipid, has been postulated to be a receptor for the HIV-1 envelope glycoprotein (Env) interaction with mucosal epithelial cells. Here, we have mimicked this interaction by using an artificial membrane containing synthetic Galcer and recombinant HIV-1 Env proteins to identify antibodies that would block the HIV-1 Env-Galcer interaction. Our study revealed that a class of vaccine-induced human antibodies potently blocks HIV-1 Env-Galcer binding by perturbing the HIV-1 Env conformation.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    URL: Article
    DOI: 10.1128/JVI.01031-14
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2014
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    Online-Ressource
    Online-Ressource
    HIV-1-Specific IgA Monoclonal Antibodies from an HIV-1 Vaccinee Mediate Galactosylceramide Blocking and Phagocytosis
    American Society for Microbiology ; 2018
    In:  Journal of Virology Vol. 92, No. 7 ( 2018-04)
    Details
    In: Journal of Virology, American Society for Microbiology, Vol. 92, No. 7 ( 2018-04)
    Kurzfassung: Vaccine-elicited humoral immune responses comprise an array of antibody forms and specificities, with only a fraction contributing to protective host immunity. Elucidation of antibody effector functions responsible for protective immunity against human immunodeficiency virus type 1 (HIV-1) acquisition is a major goal for the HIV-1 vaccine field. Immunoglobulin A (IgA) is an important part of the host defense against pathogens; however, little is known about the role of vaccine-elicited IgA and its capacity to mediate antiviral functions. To identify the antiviral functions of HIV-1-specific IgA elicited by vaccination, we cloned HIV-1 envelope-specific IgA monoclonal antibodies (MAbs) by memory B cell cultures from peripheral blood mononuclear cells from an RV144 vaccinee and produced two IgA clonal cell lines (HG129 and HG130) producing native, nonrecombinant IgA MAbs. The HG129 and HG130 MAbs mediated phagocytosis by monocytes, and HG129 blocked HIV-1 Env glycoprotein binding to galactosylceramide, an alternative HIV-1 receptor. These findings elucidate potential antiviral functions of vaccine-elicited HIV-1 envelope-specific IgA that may act to block HIV-1 acquisition at the portal of entry by preventing HIV-1 binding to galactosylceramide and mediating antibody Fc receptor-mediated virion phagocytosis. Furthermore, these findings highlight the complex and diverse interactions of vaccine-elicited IgA with pathogens that depend on IgA fine specificity and form (e.g., multimeric or monomeric) in the systemic circulation and mucosal compartments. IMPORTANCE Host-pathogen interactions in vivo involve numerous immune mechanisms that can lead to pathogen clearance. Understanding the nature of antiviral immune mechanisms can inform the design of efficacious HIV-1 vaccine strategies. Evidence suggests that both neutralizing and nonneutralizing antibodies can mediate some protection against HIV in animal models. Although numerous studies have characterized the functional properties of HIV-1-specific IgG, more studies are needed on the functional attributes of HIV-1-specific IgA, specifically for vaccine-elicited IgA. Characterization of the functional properties of HIV-1 Env-specific IgA monoclonal antibodies from human vaccine clinical trials are critical toward understanding the capacity of the host immune response to block HIV-1 acquisition.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    URL: Article
    DOI: 10.1128/JVI.01552-17
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2018
    ZDB Id: 1495529-5
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  • 3
    Online-Ressource
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    HIV-1 Vaccine-Induced C1 and V2 Env-Specific Antibodies Synergize for Increased Antiviral Activities
    American Society for Microbiology ; 2014
    In:  Journal of Virology Vol. 88, No. 14 ( 2014-07-15), p. 7715-7726
    Details
    In: Journal of Virology, American Society for Microbiology, Vol. 88, No. 14 ( 2014-07-15), p. 7715-7726
    Kurzfassung: The RV144 ALVAC/AIDSVax HIV-1 vaccine clinical trial showed an estimated vaccine efficacy of 31.2%. Viral genetic analysis identified a vaccine-induced site of immune pressure in the HIV-1 envelope (Env) variable region 2 (V2) focused on residue 169, which is included in the epitope recognized by vaccinee-derived V2 monoclonal antibodies. The ALVAC/AIDSVax vaccine induced antibody-dependent cellular cytotoxicity (ADCC) against the Env V2 and constant 1 (C1) regions. In the presence of low IgA Env antibody levels, plasma levels of ADCC activity correlated with lower risk of infection. In this study, we demonstrate that C1 and V2 monoclonal antibodies isolated from RV144 vaccinees synergized for neutralization, infectious virus capture, and ADCC. Importantly, synergy increased the HIV-1 ADCC activity of V2 monoclonal antibody CH58 at concentrations similar to that observed in plasma of RV144 vaccinees. These findings raise the hypothesis that synergy among vaccine-induced antibodies with different epitope specificities contributes to HIV-1 antiviral antibody responses and is important to induce for reduction in the risk of HIV-1 transmission. IMPORTANCE The Thai RV144 ALVAC/AIDSVax prime-boost vaccine efficacy trial represents the only example of HIV-1 vaccine efficacy in humans to date. Studies aimed at identifying immune correlates involved in the modest vaccine-mediated protection identified HIV-1 envelope (Env) variable region 2-binding antibodies as inversely correlated with infection risk, and genetic analysis identified a site of immune pressure within the region recognized by these antibodies. Despite this evidence, the antiviral mechanisms by which variable region 2-specific antibodies may have contributed to lower rates of infection remain unclear. In this study, we demonstrate that vaccine-induced HIV-1 envelope variable region 2 and constant region 1 antibodies synergize for recognition of virus-infected cells, infectious virion capture, virus neutralization, and antibody-dependent cellular cytotoxicity. This is a major step in understanding how these types of antibodies may have cooperatively contributed to reducing infection risk and should be considered in the context of prospective vaccine design.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    URL: Article
    DOI: 10.1128/JVI.00156-14
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2014
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    Online-Ressource
    Online-Ressource
    Boosting with AIDSVAX B/E Enhances Env Constant Region 1 and 2 Antibody-Dependent Cellular Cytotoxicity Breadth and Potency
    American Society for Microbiology ; 2020
    In:  Journal of Virology Vol. 94, No. 4 ( 2020-01-31)
    Details
    In: Journal of Virology, American Society for Microbiology, Vol. 94, No. 4 ( 2020-01-31)
    Kurzfassung: Induction of protective antibodies is a critical goal of HIV-1 vaccine development. One strategy is to induce nonneutralizing antibodies (NNAbs) that kill virus-infected cells, as these antibody specificities have been implicated in slowing HIV-1 disease progression and in protection. HIV-1 Env constant region 1 and 2 (C1C2) monoclonal antibodies (MAbs) frequently mediate potent antibody-dependent cellular cytotoxicity (ADCC), making them an important vaccine target. Here, we explore the effect of delayed and repetitive boosting of RV144 vaccine recipients with AIDSVAX B/E on the C1C2-specific MAb repertoire. It was found that boosting increased clonal lineage-specific ADCC breadth and potency. A ligand crystal structure of a vaccine-induced broad and potent ADCC-mediating C1C2-specific MAb showed that it bound a highly conserved Env gp120 epitope. Thus, boosting to affinity mature these types of IgG C1C2-specific antibody responses may be one method by which to make an improved HIV vaccine with higher efficacy than that seen in the RV144 trial. IMPORTANCE Over one million people become infected with HIV-1 each year, making the development of an efficacious HIV-1 vaccine an important unmet medical need. The RV144 human HIV-1 vaccine regimen is the only HIV-1 clinical trial to date to demonstrate vaccine efficacy. An area of focus has been on identifying ways by which to improve upon RV144 vaccine efficacy. The RV305 HIV-1 vaccine regimen was a follow-up boost of RV144 vaccine recipients that occurred 6 to 8 years after the conclusion of RV144. Our study focused on the effect of delayed boosting in humans on the vaccine-induced Env constant region 1 and 2 (C1C2)-specific antibody repertoire. It was found that boosting with an HIV-1 Env vaccine increased C1C2-specific antibody-dependent cellular cytotoxicity potency and breadth.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    URL: Article
    DOI: 10.1128/JVI.01120-19
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2020
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    Online-Ressource
    Online-Ressource
    Antigenicity and Immunogenicity of RV144 Vaccine AIDSVAX Clade E Envelope Immunogen Is Enhanced by a gp120 N-Terminal Deletion
    American Society for Microbiology ; 2013
    In:  Journal of Virology Vol. 87, No. 3 ( 2013-02), p. 1554-1568
    Details
    In: Journal of Virology, American Society for Microbiology, Vol. 87, No. 3 ( 2013-02), p. 1554-1568
    Kurzfassung: An immune correlates analysis of the RV144 HIV-1 vaccine trial revealed that antibody responses to the gp120 V1/V2 region correlated inversely with infection risk. The RV144 protein immunogens (A244-rp120 and MN-rgp120) were modified by an N-terminal 11-amino-acid deletion (Δ11) and addition of a herpes simplex virus (HSV) gD protein-derived tag (gD). We investigated the effects of these modifications on gp120 expression, antigenicity, and immunogenicity by comparing unmodified A244 gp120 with both Δ11 deletion and gD tag and with Δ11 only. Analysis of A244 gp120, with or without Δ11 or gD, demonstrated that the Δ11 deletion, without the addition of gD, was sufficient for enhanced antigenicity to gp120 C1 region, conformational V2, and V1/V2 gp120 conformational epitopes. RV144 vaccinee serum IgGs bound more avidly to A244 gp120 Δ11 than to the unmodified gp120, and their binding was blocked by C1, V2, and V1/V2 antibodies. Rhesus macaques immunized with the three different forms of A244 gp120 proteins gave similar levels of gp120 antibody titers, although higher antibody titers developed earlier in A244 Δ11 gp120-immunized animals. Conformational V1/V2 monoclonal antibodies (MAbs) gave significantly higher levels of blocking of plasma IgG from A244 Δ11 gp120-immunized animals than IgG from animals immunized with unmodified A244 gp120, thus indicating a qualitative difference in the V1/V2 antibodies induced by A244 Δ11 gp120. These results demonstrate that deletion of N-terminal residues in the RV144 A244 gp120 immunogen improves both envelope antigenicity and immunogenicity.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    URL: Article
    DOI: 10.1128/JVI.00718-12
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2013
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 6
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    Online-Ressource
    Infectious Virion Capture by HIV-1 gp120-Specific IgG from RV144 Vaccinees
    American Society for Microbiology ; 2013
    In:  Journal of Virology Vol. 87, No. 14 ( 2013-07-15), p. 7828-7836
    Details
    In: Journal of Virology, American Society for Microbiology, Vol. 87, No. 14 ( 2013-07-15), p. 7828-7836
    Kurzfassung: The detailed examination of the antibody repertoire from RV144 provides a unique template for understanding potentially protective antibody functions. Some potential immune correlates of protection were untested in the correlates analyses due to inherent assay limitations, as well as the need to keep the correlates analysis focused on a limited number of endpoints to achieve statistical power. In an RV144 pilot study, we determined that RV144 vaccination elicited antibodies that could bind infectious virions (including the vaccine strains HIV-1 CM244 and HIV-1 MN and an HIV-1 strain expressing transmitted/founder Env, B.WITO.c). Among vaccinees with the highest IgG binding antibody profile, the majority (78%) captured the infectious vaccine strain virus (CM244), while a smaller proportion of vaccinees (26%) captured HIV-1 transmitted/founder Env virus. We demonstrated that vaccine-elicited HIV-1 gp120 antibodies of multiple specificities (V3, V2, conformational C1, and gp120 conformational) mediated capture of infectious virions. Although capture of infectious HIV-1 correlated with other humoral immune responses, the extent of variation between these humoral responses and virion capture indicates that virion capture antibodies occupy unique immunological space.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    URL: Article
    DOI: 10.1128/JVI.02737-12
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2013
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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