scholarly journals Immunization of Newborn Rhesus Macaques with Simian Immunodeficiency Virus (SIV) Vaccines Prolongs Survival after Oral Challenge with Virulent SIVmac251

2003 ◽  
Vol 77 (1) ◽  
pp. 179-190 ◽  
Author(s):  
Koen K. A. Van Rompay ◽  
Jennifer L. Greenier ◽  
Kelly Stefano Cole ◽  
Patricia Earl ◽  
Bernard Moss ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Disease Free Survival ◽  
Active Immunization ◽  
Pediatric Hiv ◽  
Maternal Antibodies ◽  
Immunization Strategies ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus

ABSTRACT There is an urgent need for active immunization strategies that, if administered shortly after birth, could protect infants in developing countries from acquiring human immunodeficiency virus (HIV) infection through breast-feeding. Better knowledge of the immunogenic properties of vaccine candidates in infants and of the effect of maternal antibodies on vaccine efficacy will aid in the development of such a neonatal HIV vaccine. Simian immunodeficiency virus (SIV) infection of infant macaques is a useful animal model of pediatric HIV infection with which to address these questions. Groups of infant macaques were immunized at birth and 3 weeks of age with either modified vaccinia virus Ankara (MVA) expressing SIV Gag, Pol, and Env (MVA-SIVgpe) or live-attenuated SIVmac1A11. One MVA-SIVgpe-immunized group had maternally derived anti-SIV antibodies prior to immunization. Animals were challenged orally at 4 weeks of age with a genetically heterogeneous stock of virulent SIVmac251. Although all animals became infected, the immunized animals mounted better antiviral antibody responses, controlled virus levels more effectively, and had a longer disease-free survival than the unvaccinated infected monkeys. Maternal antibodies did not significantly reduce the efficacy of the MVA-SIVgpe vaccine. In conclusion, although the tested vaccines delayed the onset of AIDS, further studies are warranted to determine whether a vaccine that elicits stronger early immune responses at the time of virus exposure may be able to prevent viral infection or AIDS in infants.

scholarly journals Breakthrough of SIV strain smE660 challenge in SIV strain mac239-vaccinated rhesus macaques despite potent autologous neutralizing antibody responses

2015 ◽  
Vol 112 (34) ◽  
pp. 10780-10785 ◽  
Author(s):  
Samantha L. Burton ◽  
Katie M. Kilgore ◽  
S. Abigail Smith ◽  
Sharmila Reddy ◽  
Eric Hunter ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
Neutralizing Antibody ◽  
Active Immunization ◽  
Antibody Responses ◽  
Challenge Virus ◽  
Gm Csf ◽  
Immunodeficiency Virus

Although the correlates of immunological protection from human immunodeficiency virus or simian immunodeficiency virus infection remain incompletely understood, it is generally believed that medium to high titers of serum neutralizing antibodies (nAbs) against the challenge virus will prevent infection. This paradigm is based on a series of studies in which passive transfer of HIV-specific nAbs protected rhesus macaques (RMs) from subsequent mucosal challenge with a chimeric human/simian immunodeficiency virus. However, it is unknown whether nAb titers define protection in the setting of active immunization. Here we determined serum nAb titers against breakthrough transmitted/founder (T/F) SIVsmE660-derived envelope glycoprotein (Env) variants from 14 RMs immunized with SIVmac239-based DNA-prime/modified vaccinia virus Ankara-boost vaccine regimens that included GM-CSF or CD40L adjuvants and conferred significant but incomplete protection against repeated low-dose intrarectal challenge. A single Env variant established infection in all RMs except one, with no identifiable genetic signature associated with vaccination breakthrough compared with T/F Envs from four unvaccinated monkeys. Breakthrough T/F Env pseudoviruses were potently neutralized in vitro by heterologous pooled serum from chronically SIVsmE660-infected monkeys at IC50 titers exceeding 1:1,000,000. Remarkably, the T/F Env pseudoviruses from 13 of 14 monkeys were also susceptible to neutralization by autologous prechallenge serum at in vitro IC50 titers ranging from 1:742–1:10,832. These titers were similar to those observed in vaccinated RMs that remained uninfected. These data suggest that the relationship between serum nAb titers and protection from mucosal SIV challenge in the setting of active immunization is more complex than previously recognized, warranting further studies into the balance between immune activation, target cell availability, and protective antibody responses.

scholarly journals Reduced Protection from Simian Immunodeficiency Virus SIVmac251 Infection Afforded by Memory CD8+ T Cells Induced by Vaccination during CD4+ T-Cell Deficiency

2008 ◽  
Vol 82 (19) ◽  
pp. 9629-9638 ◽  
Author(s):  
Monica Vaccari ◽  
Joseph Mattapallil ◽  
Kaimei Song ◽  
Wen-Po Tsai ◽  
Anna Hryniewicz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Interleukin 2 ◽  
T Cell Responses ◽  
Memory Cd8 T Cells ◽  
Cell Responses ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus

ABSTRACT Adaptive CD4+ and CD8+ T-cell responses have been associated with control of human immunodeficiency virus/simian immunodeficiency virus (HIV/SIV) replication. Here, we have designed a study with Indian rhesus macaques to more directly assess the role of CD8 SIV-specific responses in control of viral replication. Macaques were immunized with a DNA prime-modified vaccinia virus Ankara (MVA)-SIV boost regimen under normal conditions or under conditions of antibody-induced CD4+ T-cell deficiency. Depletion of CD4+ cells was performed in the immunized macaques at the peak of SIV-specific CD4+ T-cell responses following the DNA prime dose. A group of naïve macaques was also treated with the anti-CD4 depleting antibody as a control, and an additional group of macaques immunized under normal conditions was depleted of CD8+ T cells prior to challenge exposure to SIVmac251. Analysis of the quality and quantity of vaccine-induced CD8+ T cells demonstrated that SIV-specific CD8+ T cells generated under conditions of CD4+ T-cell deficiency expressed low levels of Bcl-2 and interleukin-2 (IL-2), and plasma virus levels increased over time. Depletion of CD8+ T cells prior to challenge exposure abrogated vaccine-induced protection as previously shown. These data support the notion that adaptive CD4+ T cells are critical for the generation of effective CD8+ T-cell responses to SIV that, in turn, contribute to protection from AIDS. Importantly, they also suggest that long-term protection from disease will be afforded only by T-cell vaccines for HIV that provide a balanced induction of CD4+ and CD8+ T-cell responses and protect against early depletion of CD4+ T cells postinfection.

scholarly journals Effects of Fecal Microbial Transplantation on Microbiome and Immunity in Simian Immunodeficiency Virus-Infected Macaques

2016 ◽  
Vol 90 (10) ◽  
pp. 4981-4989 ◽  
Author(s):  
Tiffany Hensley-McBain ◽  
Alexander S. Zevin ◽  
Jennifer Manuzak ◽  
Elise Smith ◽  
Jillian Gile ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Simian Immunodeficiency Virus ◽  
Antibiotic Treatment ◽  
T Cell Activation ◽  
Rhesus Macaques ◽  
Bacterial Community Composition ◽  
Intestinal Microbiome ◽  
Th22 Cells ◽  
Immunodeficiency Virus ◽  
Taxonomic Groups

ABSTRACTAn altered intestinal microbiome during chronic human immunodeficiency virus (HIV) infection is associated with mucosal dysfunction, inflammation, and disease progression. We performed a preclinical evaluation of the safety and efficacy of fecal microbiota transplantation (FMT) as a potential therapeutic in HIV-infected individuals. Antiretroviral-treated, chronically simian immunodeficiency virus (SIV)-infected rhesus macaques received antibiotics followed by FMT. The greatest microbiota shift was observed after antibiotic treatment. The bacterial community composition at 2 weeks post-FMT resembled the pre-FMT community structure, although differences in the abundances of minor bacterial populations remained. Immunologically, we observed significant increases in the number of peripheral Th17 and Th22 cells and reduced CD4+T cell activation in gastrointestinal tissues post-FMT. Importantly, the transplant was well tolerated with no negative clinical side effects. Although this pilot study did not control for the differential contributions of antibiotic treatment and FMT to the observed results, the data suggest that FMT may have beneficial effects that should be further evaluated in larger studies.IMPORTANCEDue to the immunodeficiency and chronic inflammation that occurs during HIV infection, determination of the safety of FMT is crucial to prevent deleterious consequences if it is to be used as a treatment in the future. Here we used the macaque model of HIV infection and performed FMT on six chronically SIV-infected rhesus macaques on antiretroviral treatment. In addition to providing a preclinical demonstration of the safety of FMT in primates infected with a lentivirus, this study provided a unique opportunity to examine the relationships between alterations to the microbiome and immunological parameters. In this study, we found increased numbers of Th17 and Th22 cells as well as decreased activation of CD4+T cells post-FMT, and these changes correlated most strongly across all sampling time points with lower-abundance taxonomic groups and other taxonomic groups in the colon. Overall, these data provide evidence that changes in the microbiome, particularly in terms of diversity and changes in minor populations, can enhance immunity and do not have adverse consequences.

scholarly journals Signatures in Simian Immunodeficiency Virus SIVsmE660 Envelope gp120 Are Associated with Mucosal Transmission but Not Vaccination Breakthrough in Rhesus Macaques

2015 ◽  
Vol 90 (4) ◽  
pp. 1880-1887 ◽  
Author(s):  
S. Abigail Smith ◽  
Katie M. Kilgore ◽  
Sudhir Pai Kasturi ◽  
Bali Pulendran ◽  
Eric Hunter ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Mucosal Barrier ◽  
Primate Research ◽  
Mucosal Transmission ◽  
Strong Selection ◽  
Immunization Strategies ◽  
Immunodeficiency Virus ◽  
Key Sites ◽  
Hiv 1

ABSTRACTMucosal surfaces are vulnerable to human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) infection and thus are key sites for eliciting vaccine-mediated protection. Vaccine protocols carried out at the Yerkes Primate Research Center utilized SIVmac239-based immunization strategies with intrarectal and intravaginal SIVsmE660 challenge of rhesus macaques. We investigated whether there were genetic signatures associated with SIVsmE660 intrarectal and intravaginal transmissions in vaccinated and unvaccinated monkeys. When transmitted/founder (T/F) envelope (Env) sequences from 49 vaccinated and 15 unvaccinated macaques were compared to each other, we were unable to identify any vaccine breakthrough signatures. In contrast, when the vaccinated and control T/F Envs were combined and compared to the challenge stock, residues at gp120 positions 23, 45, 47, and 70 (Ile-Ala-Lys-Asn [I-A-K-N]) emerged as signatures of mucosal transmission. However, T/F Envs derived from intrarectal and intravaginal infections were not different. Our data suggest that the vaginal and rectal mucosal environments both imposed a strong selection bias for SIVsmE660 variants carrying I-A-K-N that was not further enhanced by immunization. These findings, combined with the strong conservation of A-K-N in most HIV-2/SIVsmm isolates and the analogous residues in HIV-1/SIVcpz isolates, suggest that these residues confer increased transmission fitness to SIVsmE660.IMPORTANCEMost HIV-1 infections occur across a mucosal barrier, and it is therefore important to understand why these sites are vulnerable and how to protect them with a vaccine. To gain insight into these questions, we studied rhesus macaques that were vaccinated with SIVmac239 and unvaccinated controls to determine whether the SIVsmE660 viral variants that infected these two groups were different. We did not find differences between viral variants in the absence versus presence of vaccination-induced immunity, but we did find that the SIVsmE660 viral variants that infected the monkeys, regardless of vaccination, were different from the dominant population found in the viral challenge inoculum. Our data suggest that the mucosal environments of the vagina and rectum both impose a strong selection for the SIVsmE660 variants in the challenge inoculum that are most like SIV and HIVs that circulate in nature.

scholarly journals Effective Induction of Simian Immunodeficiency Virus-Specific Cytotoxic T Lymphocytes in Macaques by Using a Multiepitope Gene and DNA Prime-Modified Vaccinia Virus Ankara Boost Vaccination Regimen

1999 ◽  
Vol 73 (9) ◽  
pp. 7524-7532 ◽  
Author(s):  
Tomas Hanke ◽  
Rachel V. Samuel ◽  
Tom J. Blanchard ◽  
Veronica C. Neumann ◽  
Todd M. Allen ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Peripheral Blood Lymphocytes ◽  
Vaccination Regimen ◽  
Boost Regimen ◽  
Boost Vaccination ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus

ABSTRACT DNA and modified vaccinia virus Ankara (MVA) are vaccine vehicles suitable and safe for use in humans. Here, by using a multicytotoxic T-lymphocyte (CTL) epitope gene and a DNA prime-MVA boost vaccination regimen, high levels of CTLs specific for a single simian immunodeficiency virus (SIV) gag-derived epitope were elicited in rhesus macaques. These vaccine-induced CTLs were capable of killing SIV-infected cells in vitro. Fluorescence-activated cell sorter analysis using soluble tetrameric major histocompatibility complex-peptide complexes showed that the vaccinated animals had 1 to 5% circulating CD8+ lymphocytes specific for the vaccine epitope, frequencies comparable to those in SIV-infected monkeys. Upon intrarectal challenge with pathogenic SIVmac251, no evidence for protection was observed in at least two of the three vaccinated animals. This study does not attempt to define correlates of protective immunity nor design a protective vaccine against immunodeficiency viruses, but it demonstrates clearly that the DNA prime-MVA boost regimen is an effective protocol for induction of CTLs in macaques. It also shows that powerful tools for studying the role of CTLs in the control of SIV and human immunodeficiency virus infections are now available: epitope-based vaccines, a protocol for an effective induction of CTLs in primates, and a simple and sensitive method for quantitation of epitope-specific T cells. The advantages of the DNA prime-MVA boost regimen as well as the correlations of tetramer staining of peripheral blood lymphocytes with CTL killing in vitro and postchallenge control of viremia are discussed.

scholarly journals SIV/SHIV-Zika coinfection does not alter disease pathogenesis in adult non-pregnant Rhesus Macaques

2018 ◽  
Author(s):  
Mehdi R. M. Bidokhti ◽  
Debashis Dutta ◽  
Lepakshe S. V. Madduri ◽  
Shawna M. Woollard ◽  
Robert Norgren ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Hiv Infection ◽  
Simian Immunodeficiency Virus ◽  
Zika Virus ◽  
Rhesus Macaques ◽  
Epidemiological Studies ◽  
Disease Pathogenesis ◽  
Viral Loads ◽  
Immunodeficiency Virus ◽  
Tropical Infectious Diseases

AbstractDue to the large geographical overlap of populations exposed to Zika virus (ZIKV) and human immunodeficiency virus (HIV), understanding disease pathogenesis in such coinfections is urgently needed. We used chronically infected simian immunodeficiency virus and chimeric simian human immunodeficiency virus (SIV/SHIV) macaques and inoculated with ZIKV. Plasma viral loads of both SIV/SHIV and ZIKV showed no significant changes as compared to ZIKV alone-infected animals. Tissue clearance of ZIKV was observed similarly. Furthermore, minimal changes in cytokines/chemokines were observed. Collectively, these data suggest that coinfection may not alter disease pathogenesis and warrants large HIV-ZIKV epidemiological studies to validate these findings.Author SummaryThe co-infection incidence of human immunodeficiency virus (HIV) infection and neglected tropical infectious diseases is increasing due to the large geographical overlap of populations exposed to both of these viruses. Thus, researching on such coinfection is of particular importance. In this study, we investigated HIV-ZIKV coinfection dynamics in adult non-pregnant Rhesus Macaques model chronically infected with simian immunodeficiency virus (SIV) - or chimeric simian human immunodeficiency virus (SHIV). We found that post ZIKV inoculation, plasma viral loads were similar to ZIKV alone infected animals in addition to minimal changes of cytokines. Dynamics of SIV and SHIV also did not change. Tissue clearance of ZIKV was found 67 months later. Our findings provide insights into HIV-ZKIV coinfection to determine the alteration of their pathogenesis.

scholarly journals Evaluating the Intactness of Persistent Viral Genomes in Simian Immunodeficiency Virus-Infected Rhesus Macaques after Initiating Antiretroviral Therapy within One Year of Infection

2019 ◽  
Vol 94 (1) ◽  
Author(s):  
Samuel Long ◽  
Christine M. Fennessey ◽  
Laura Newman ◽  
Carolyn Reid ◽  
Sean P. O’Brien ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Hiv Infection ◽  
Simian Immunodeficiency Virus ◽  
Genome Sequencing ◽  
Real Time Pcr ◽  
Rhesus Macaques ◽  
Viral Reservoir ◽  
Combination Antiretroviral Therapy ◽  
Viral Dna ◽  
Immunodeficiency Virus

ABSTRACT The major obstacle to more-definitive treatment for HIV infection is the early establishment of virus that persists despite long-term combination antiretroviral therapy (cART) and can cause recrudescent viremia if cART is interrupted. Previous studies of HIV DNA that persists despite cART indicated that only a small fraction of persistent viral sequences was intact. Experimental simian immunodeficiency virus (SIV) infections of nonhuman primates (NHPs) are essential models for testing interventions designed to reduce the viral reservoir. We studied the viral genomic integrity of virus that persists during cART under conditions typical of many NHP reservoir studies, specifically with cART started within 1 year postinfection and continued for at least 9 months. The fraction of persistent DNA in SIV-infected NHPs starting cART during acute or chronic infection was assessed with a multiamplicon, real-time PCR assay designed to analyze locations that are regularly spaced across the viral genome to maximize coverage (collectively referred to as “tile assay”) combined with near-full-length (nFL) single-genome sequencing. The tile assay is used to rapidly screen for major deletions, with nFL sequence analysis used to identify additional potentially inactivating mutations. Peripheral blood mononuclear cells (PBMC) from animals started on cART within 1 month of infection, sampled at least 9 months after cART initiation, contained at least 80% intact genomes, whereas those from animals started on cART 1 year postinfection and treated for 1 year contained intact genomes only 47% of the time. The most common defect identified was large deletions, with the remaining defects caused by APOBEC-mediated mutations, frameshift mutations, and inactivating point mutations. Overall, this approach can be used to assess the intactness of persistent viral DNA in NHPs. IMPORTANCE Molecularly defining the viral reservoir that persists despite antiretroviral therapy and that can lead to rebound viremia if antiviral therapy is removed is critical for testing interventions aimed at reducing this reservoir. In HIV infection in humans with delayed treatment initiation and extended treatment duration, persistent viral DNA has been shown to be dominated by nonfunctional genomes. Using multiple real-time PCR assays across the genome combined with near-full-genome sequencing, we defined SIV genetic integrity after 9 to 18 months of combination antiretroviral therapy in rhesus macaques starting therapy within 1 year of infection. In the animals starting therapy within a month of infection, the vast majority of persistent DNA was intact and presumptively functional. Starting therapy within 1 year increased the nonintact fraction of persistent viral DNA. The approach described here allows rapid screening of viral intactness and is a valuable tool for assessing the efficacy of novel reservoir-reducing interventions.

scholarly journals Induction of simian immunodeficiency virus (SIV)-specific CTL in rhesus macaques by vaccination with modified vaccinia virus Ankara expressing SIV transgenes: influence of pre-existing anti-vector immunity

2001 ◽  
Vol 82 (9) ◽  
pp. 2215-2223 ◽  
Author(s):  
Sally Sharpe ◽  
Natasha Polyanskaya ◽  
Mike Dennis ◽  
Gerd Sutter ◽  
Tomáš Hanke ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Simian Immunodeficiency Virus ◽  
Vaccine Development ◽  
Cytotoxic T Lymphocyte ◽  
Rhesus Macaques ◽  
Lymphoid Tissues ◽  
Specific Response ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus ◽  
Definition Of

A major aim in AIDS vaccine development is the definition of strategies to stimulate strong and durable cytotoxic T lymphocyte (CTL) responses. Here we report that simian immunodeficiency virus (SIV)-specific CTL developed in 4/4 macaques following a single intramuscular injection of modified vaccinia virus Ankara (MVA) constructs expressing both structural and regulatory/accessory genes of SIV. In two animals Nef-specific responses persisted, but other responses diminished and new responses were not revealed, following further vaccination. Vaccination of another two macaques, expressing Mamu A*01 MHC class I, with MVA constructs containing nef and gag–pol under the control of the moderate strength natural vaccinia virus early/late promoter P7.5, again induced an early Nef-specific response, whereas responses to Gag remained undetectable. Anti-vector immunity induced by this immunization was shown to prevent the efficient stimulation of CTL directed to the cognate Gag epitope, p11C C-M, following vaccination with another MVA construct expressing SIV Gag–Pol under a strong synthetic vaccinia virus-specific promoter. In contrast, vaccination of a previously unexposed animal resulted in a SIV-specific CTL response widely disseminated in lymphoid tissues including lymph nodes associated with the rectal and genital routes of SIV entry. Thus, despite the highly attenuated nature of MVA, repeated immunization may elicit sufficient anti-vector immunity to limit the effectiveness of later vaccination.

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