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  • 1
    In: Journal of Virology, American Society for Microbiology, Vol. 94, No. 24 ( 2020-11-23)
    Kurzfassung: An efficacious human immunodeficiency virus (HIV) vaccine will likely require induction of both mucosal and systemic immune responses. We compared the immunogenicity and protective efficacy of two mucosal/systemic vaccine regimens and investigated their effects on the rectal microbiome. Rhesus macaques were primed twice mucosally with replication-competent adenovirus type 5 host range mutant (Ad5hr)-simian immunodeficiency virus (SIV) recombinants and boosted twice intramuscularly with ALVAC-SIV recombinant plus SIV gp120 protein or with DNA for SIV genes and rhesus interleukin-12 plus SIV gp120 protein. Controls received empty Ad5hr vector and alum adjuvant only. Both regimens elicited strong, comparable mucosal and systemic cellular and humoral immunity. Prevaccination rectal microbiomes of males and females differed and significantly changed over the course of immunization, most strongly in females after Ad5hr immunizations. Following repeated low-dose intrarectal SIV challenges, both vaccine groups exhibited modestly but significantly reduced acute viremia. Male and female controls exhibited similar acute viral loads; however, vaccinated females, but not males, exhibited lower levels of acute viremia, compared to same-sex controls. Few differences in adaptive immune responses were observed between the sexes. Striking differences in correlations of the rectal microbiome of males and females with acute viremia and immune responses associated with protection were seen and point to effects of the microbiome on vaccine-induced immunity and viremia control. Our study clearly demonstrates direct effects of a mucosal SIV vaccine regimen on the rectal microbiome and validates our previously reported SIV vaccine-induced sex bias. Sex and the microbiome are critical factors that should not be overlooked in vaccine design and evaluation. IMPORTANCE Differences in HIV pathogenesis between males and females, including immunity postinfection, have been well documented, as have steroid hormone effects on the microbiome, which is known to influence mucosal immune responses. Few studies have applied this knowledge to vaccine trials. We investigated two SIV vaccine regimens combining mucosal priming immunizations and systemic protein boosting. We again report a vaccine-induced sex bias, with female rhesus macaques but not males displaying significantly reduced acute viremia. The vaccine regimens, especially the mucosal primes, significantly altered the rectal microbiome. The greatest effects were in females. Striking differences between female and male macaques in correlations of prevalent rectal bacteria with viral loads and potentially protective immune responses were observed. Effects of the microbiome on vaccine-induced immunity and viremia control require further study by microbiome transfer. However, the findings presented highlight the critical importance of considering effects of sex and the microbiome in vaccine design and evaluation.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2020
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    In: Journal of Virology, American Society for Microbiology, Vol. 91, No. 4 ( 2017-02-15)
    Kurzfassung: In a recent study, we found that protection following simian immunodeficiency virus (SIV) exposure correlated with rectal plasma cell frequency in vaccinated female rhesus macaques. We sought to determine if the same macaques maintained high mucosal plasma cell frequencies postinfection and if this translated to reduced viremia. Although delayed SIV acquisition did not predict subsequent viral control, alterations existed in the distribution of plasma cells and plasmablasts between macaques that exhibited high or low viremia. Flow cytometric analysis of cells from rectal biopsy specimens, bone marrow, and mesenteric lymph nodes of vaccinated infected, unvaccinated infected, and uninfected macaques identified two main IRF4 hi subsets of interest: CD138 + plasma cells, and CD138 − plasmablasts. In rectal tissue, plasma cell frequency positively correlated with plasma viremia and unvaccinated macaques had increased plasma cells and plasmablasts compared to vaccinated animals. Likewise, plasmablast frequency in the mesenteric lymph node correlated with viremia. However, in bone marrow, plasmablast frequency negatively correlated with viremia. Accordingly, low-viremic macaques had a higher frequency of both bone marrow IRF4 hi subsets than did animals with high viremia. Significant reciprocal relationships between rectal and bone marrow plasmablasts suggested that efficient trafficking to the bone marrow as opposed to the rectal mucosa was linked to viral control. mRNA expression analysis of proteins involved in establishment of plasma cell niches in sorted bone marrow and rectal cell populations further supported this model and revealed differential mRNA expression patterns in these tissues. IMPORTANCE As key antibody producers, plasma cells and plasmablasts are critical components of vaccine-induced immunity to human immunodeficiency virus type 1 (HIV-1) in humans and SIV in the macaque model; however, few have attempted to examine the role of these cells in viral suppression postinfection. Our results suggest that plasmablast trafficking to and retention in the bone marrow play a previously unappreciated role in viral control and contrast the potential contribution of mucosal plasma cells to mediate protection at sites of infection with that of bone marrow plasmablasts and plasma cells to control viremia during chronic infection. Manipulation of niche factors influencing the distribution and maintenance of these critical antibody-secreting cells may serve as potential therapeutic targets to enhance antiviral responses postvaccination and postinfection.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2017
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    In: Clinical Immunology, Elsevier BV, Vol. 153, No. 2 ( 2014-08), p. 308-322
    Materialart: Online-Ressource
    ISSN: 1521-6616
    RVK:
    Sprache: Englisch
    Verlag: Elsevier BV
    Publikationsdatum: 2014
    ZDB Id: 1462862-4
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    In: Journal of Immunological Methods, Elsevier BV, Vol. 412 ( 2014-10), p. 78-84
    Materialart: Online-Ressource
    ISSN: 0022-1759
    RVK:
    Sprache: Englisch
    Verlag: Elsevier BV
    Publikationsdatum: 2014
    ZDB Id: 1500495-8
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 201, No. 8 ( 2018-10-15), p. 2287-2302
    Kurzfassung: Neutrophils are the most abundant leukocyte and play a critical role in the initial response to an Ag. Recently, their ability to contribute to adaptive immunity has been highlighted. We evaluated the ability of neutrophils from blood to contribute to the adaptive immune response in a preclinical rhesus macaque SIV vaccine trial. Replication-competent adenovirus-SIV recombinants induced neutrophil activation, B cell help markers, and enhanced ability to generate reactive oxygen species. Boosting with SIV vaccines (adjuvant together with ALVAC or DNA plus envelope protein) elicited significant neutrophil responses. Serum cytokine and chemokine levels induced correlated with the frequency of neutrophil subsets expressing IL-21, myeloperoxidase, and CD64. Post–SIV infection, neutrophils exhibited dysfunction, both phenotypically and functionally. B cells from protected and infected macaques cocultured with autologous polymorphonuclear cells, consisting primarily of neutrophils, were activated, underwent class switching, and produced Abs. This B cell help was not aided by addition of IL-10 and was largely contact dependent. Numerous genes associated with inflammation, Ab production, and chemotaxis were upregulated in the cocultured B cells. We conclude that immune stimulation by vaccination or antigenic exposure imparts a greater ability of neutrophils to contribute to the adaptive immune response. Harnessing this granulocytic response has the potential to improve vaccine efficacy.
    Materialart: Online-Ressource
    ISSN: 0022-1767 , 1550-6606
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: The American Association of Immunologists
    Publikationsdatum: 2018
    ZDB Id: 1475085-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 6
    In: Journal of Virology, American Society for Microbiology, Vol. 93, No. 4 ( 2019-02-15)
    Kurzfassung: T follicular helper (T FH ) cells are fundamental in germinal center (GC) maturation and selection of antigen-specific B cells within secondary lymphoid organs. GC-resident T FH cells have been fully characterized in human immunodeficiency virus (HIV) infection. However, the role of GC T FH cells in GC B cell responses following various simian immunodeficiency virus (SIV) vaccine regimens in rhesus macaques (RMs) has not been fully investigated. We characterized GC T FH cells of RMs over the course of a mucosal/systemic vaccination regimen to elucidate GC formation and SIV humoral response generation. Animals were mucosally primed twice with replicating adenovirus type 5 host range mutant (Ad5hr)-SIV recombinants and systemically boosted with ALVAC-SIV M766 Gag/Pro/gp120-TM and SIV M766 & CG7V gD-gp120 proteins formulated in alum hydroxide (ALVAC/Env) or DNA encoding SIVenv/SIVGag/rhesus interleukin 12 (IL-12) plus SIV M766 & CG7V gD-gp120 proteins formulated in alum phosphate (DNA & Env). Lymph nodes were biopsied in macaque subgroups prevaccination and at day 3, 7, or 14 after the 2nd Ad5hr-SIV prime and the 2nd vector/Env boost. Evaluations of GC T FH and GC B cell dynamics including correlation analyses supported a significant role for early GC T FH cells in providing B cell help during initial phases of GC formation. GC T FH responses at day 3 post-mucosal priming were consistent with generation of Env-specific memory B cells in GCs and elicitation of prolonged Env-specific humoral immunity in the rectal mucosa. GC Env-specific memory B cell responses elicited early post-systemic boosting correlated significantly with decreased viremia postinfection. Our results highlight the importance of early GC T FH cell responses for robust GC maturation and generation of long-lasting SIV-specific humoral responses at mucosal and systemic sites. Further investigation of GC T FH cell dynamics should facilitate development of an efficacious HIV vaccine. IMPORTANCE The modest HIV protection observed in the human RV144 vaccine trial associated antibody responses with vaccine efficacy. T follicular helper (T FH ) cells are CD4 + T cells that select antibody secreting cells with high antigenic affinity in germinal centers (GCs) within secondary lymphoid organs. To evaluate the role of T FH cells in eliciting prolonged virus-specific humoral responses, we vaccinated rhesus macaques with a combined mucosal prime/systemic boost regimen followed by repeated low-dose intrarectal challenges with SIV, mimicking human exposure to HIV-1. Although the vaccine regimen did not prevent SIV infection, decreased viremia was observed in the immunized macaques. Importantly, vaccine-induced T FH responses elicited at day 3 postimmunization and robust GC maturation were strongly associated. Further, early T FH -dependent SIV-specific B cell responses were also correlated with decreased viremia. Our findings highlight the contribution of early vaccine-induced GC T FH responses to elicitation of SIV-specific humoral immunity and implicate their participation in SIV control.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2019
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 7
    In: Journal of Clinical Investigation, American Society for Clinical Investigation, Vol. 129, No. 3 ( 2019-2-18), p. 1314-1328
    Materialart: Online-Ressource
    ISSN: 0021-9738 , 1558-8238
    Sprache: Englisch
    Verlag: American Society for Clinical Investigation
    Publikationsdatum: 2019
    ZDB Id: 2018375-6
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 8
    In: Journal of Virology, American Society for Microbiology, Vol. 92, No. 19 ( 2018-10)
    Kurzfassung: An effective human immunodeficiency virus (HIV) vaccine has yet to be developed, and defining immune correlates of protection against HIV infection is of paramount importance to inform future vaccine design. The complement system is a component of innate immunity that can directly lyse pathogens and shape adaptive immunity. To determine if complement lysis of simian immunodeficiency virus (SIV) and/or SIV-infected cells represents a protective immune correlate against SIV infection, sera from previously vaccinated and challenged rhesus macaques were analyzed for the induction of antibody-dependent complement-mediated lysis (ADCML). Importantly, the vaccine regimen, consisting of a replication-competent adenovirus type 5 host-range mutant SIV recombinant prime followed by a monomeric gp120 or oligomeric gp140 boost, resulted in overall delayed SIV acquisition only in females. Here, sera from all vaccinated animals induced ADCML of SIV and SIV-infected cells efficiently, regardless of sex. A modest correlation of SIV lysis with a reduced infection rate in males but not females, together with a reduced peak viremia in all animals boosted with gp140, suggested a potential for influencing protective efficacy. Gag-specific IgG and gp120-specific IgG and IgM correlated with SIV lysis in females, while Env-specific IgM correlated with SIV-infected cell lysis in males, indicating sex differences in vaccine-induced antibody characteristics and function. In fact, gp120/gp140-specific antibody functional correlates between antibody-dependent cellular cytotoxicity, antibody-dependent phagocytosis, and ADCML as well as the gp120-specific IgG glycan profiles and the corresponding ADCML correlations varied depending on the sex of the vaccinees. Overall, these data suggest that sex influences vaccine-induced antibody function, which should be considered in the design of globally effective HIV vaccines in the future. IMPORTANCE An HIV vaccine would thwart the spread of HIV infection and save millions of lives. Unfortunately, the immune responses conferring universal protection from HIV infection are poorly defined. The innate immune system, including the complement system, is an evolutionarily conserved, basic means of protection from infection. Complement can prevent infection by directly lysing incoming pathogens. We found that vaccination against SIV in rhesus macaques induces antibodies that are capable of directing complement lysis of SIV and SIV-infected cells in both sexes. We also found sex differences in vaccine-induced antibody species and their functions. Overall, our data suggest that sex affects vaccine-induced antibody characteristics and function and that males and females might require different immune responses to protect against HIV infection. This information could be used to generate highly effective HIV vaccines for both sexes in the future.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2018
    ZDB Id: 1495529-5
    Standort Signatur Einschränkungen Verfügbarkeit
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