scholarly journals Antigenic Stimulation Specifically Reactivates the Replication of Archived Simian Immunodeficiency Virus Genomes in Chronically Infected Macaques

2005 ◽  
Vol 79 (17) ◽  
pp. 11231-11238 ◽  
Author(s):  
Céline Renoux ◽  
Simon Wain-Hobson ◽  
Bruno Hurtrel ◽  
Rémi Cheynier
Keyword(s):  
T Cells ◽  
Simian Immunodeficiency Virus ◽  
Viral Evolution ◽  
Direct Consequence ◽  
Viral Fitness ◽  
Viral Population ◽  
Viral Quasispecies ◽  
Cell Clones ◽  
Immunodeficiency Virus ◽  
Virus Genomes

ABSTRACT Human immunodeficiency virus/simian immunodeficiency virus (SIV) diversification is a direct consequence of viral replication and occurs principally in secondary lymphoid organs where CD4+ T cells are activated and proliferate. However, the evolution of viral quasispecies may also be driven by various nonexclusive mechanisms, including adaptation to specific immune responses and modification of viral fitness. Analysis of viral quasispecies in SIV-infected macaques subjected to repeated antigenic stimulations allowed us to demonstrate transient expansions of SIV populations that were highly dependent upon activation of antigen-specific T cells. T-cell clones expanded in response to a particular antigen were infected by a specific viral population and persisted for prolonged periods. Upon a second stimulation by encounter with the same antigen, these specific genomes were at the origin of a new burst of replication, leading to rapid but transient replacement of the viral quasispecies in blood. Finally, longitudinal analysis of SIV sequence variation during and between antigenic stimulations revealed that viral evolution is mostly constrained to periods of strong immunological activity.

scholarly journals Spatiotemporal dynamics of simian immunodeficiency virus brain infection in CD8+ lymphocyte-depleted rhesus macaques with neuroAIDS

2014 ◽  
Vol 95 (12) ◽  
pp. 2784-2795 ◽  
Author(s):  
Samantha L. Strickland ◽  
Brittany D. Rife ◽  
Susanna L. Lamers ◽  
David J. Nolan ◽  
Nazle M. C. Veras ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Viral Evolution ◽  
Viral Population ◽  
Steady Increase ◽  
Lymphoid Tissues ◽  
Peripheral Tissues ◽  
Immunodeficiency Virus ◽  
The Brain

Despite the success of combined antiretroviral therapy in controlling viral replication in human immunodeficiency virus (HIV)-infected individuals, HIV-associated neurocognitive disorders, commonly referred to as neuroAIDS, remain a frequent and poorly understood complication. Infection of CD8+ lymphocyte-depleted rhesus macaques with the SIVmac251 viral swarm is a well-established rapid disease model of neuroAIDS that has provided critical insight into HIV-1-associated neurocognitive disorder onset and progression. However, no studies so far have characterized in depth the relationship between intra-host viral evolution and pathogenesis in this model. Simian immunodeficiency virus (SIV) env gp120 sequences were obtained from six infected animals. Sequences were sampled longitudinally from several lymphoid and non-lymphoid tissues, including individual lobes within the brain at necropsy, for four macaques; two animals were sacrificed at 21 days post-infection (p.i.) to evaluate early viral seeding of the brain. Bayesian phylodynamic and phylogeographic analyses of the sequence data were used to ascertain viral population dynamics and gene flow between peripheral and brain tissues, respectively. A steady increase in viral effective population size, with a peak occurring at ~50–80 days p.i., was observed across all longitudinally monitored macaques. Phylogeographic analysis indicated continual viral seeding of the brain from several peripheral tissues throughout infection, with the last migration event before terminal illness occurring in all macaques from cells within the bone marrow. The results strongly supported the role of infected bone marrow cells in HIV/SIV neuropathogenesis. In addition, our work demonstrated the applicability of Bayesian phylogeography to intra-host studies in order to assess the interplay between viral evolution and pathogenesis.

scholarly journals Significant Depletion of CD4+T Cells Occurs in the Oral Mucosa during Simian Immunodeficiency Virus Infection with the Infected CD4+T Cell Reservoir Continuing to Persist in the Oral Mucosa during Antiretroviral Therapy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jeffy George ◽  
Wendeline Wagner ◽  
Mark G. Lewis ◽  
Joseph J. Mattapallil
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Simian Immunodeficiency Virus ◽  
Oral Mucosa ◽  
Mucosal Immunity ◽  
Viral Reservoir ◽  
Long Term Outcome ◽  
Immunodeficiency Virus ◽  
A Minor

Human and simian immunodeficiency virus (HIV and SIV) infections are characterized by manifestation of numerous opportunistic infections and inflammatory conditions in the oral mucosa. The loss of CD4+T cells that play a critical role in maintaining mucosal immunity likely contributes to this process. Here we show that CD4+T cells constitute a minor population of T cells in the oral mucosa and display a predominantly central memory phenotype mirroring other mucosal sites such as the rectal mucosa. Chronic SIV infection was associated with a near total depletion of CD4+T cells in the oral mucosa that appear to repopulate during antiretroviral therapy (ART). Repopulating CD4+T cells harbored a large fraction of Th17 cells suggesting that ART potentially reconstitutes oral mucosal immunity. However, a minor fraction of repopulating CD4+T cells harbored SIV DNA suggesting that the viral reservoir continues to persist in the oral mucosa during ART. Therapeutic approaches aimed at obtaining sustainable CD4+T cell repopulation in combination with strategies that can eradicate the latent viral reservoir in the oral mucosa are essential for better oral health and long-term outcome in HIV infected patients.

scholarly journals Increased Loss of CCR5+ CD45RA− CD4+ T Cells in CD8+ Lymphocyte-Depleted Simian Immunodeficiency Virus-Infected Rhesus Monkeys

2008 ◽  
Vol 82 (11) ◽  
pp. 5618-5630 ◽  
Author(s):  
Ronald S. Veazey ◽  
Paula M. Acierno ◽  
Kimberly J. McEvers ◽  
Susanne H. C. Baumeister ◽  
Gabriel J. Foster ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Simian Immunodeficiency Virus ◽  
Peripheral Blood ◽  
T Cell Responses ◽  
Lymphocyte Depletion ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Siv Infection

ABSTRACT Previously we have shown that CD8+ T cells are critical for containment of simian immunodeficiency virus (SIV) viremia and that rapid and profound depletion of CD4+ T cells occurs in the intestinal tract of acutely infected macaques. To determine the impact of SIV-specific CD8+ T-cell responses on the magnitude of the CD4+ T-cell depletion, we investigated the effect of CD8+ lymphocyte depletion during primary SIV infection on CD4+ T-cell subsets and function in peripheral blood, lymph nodes, and intestinal tissues. In peripheral blood, CD8+ lymphocyte-depletion changed the dynamics of CD4+ T-cell loss, resulting in a more pronounced loss 2 weeks after infection, followed by a temporal rebound approximately 2 months after infection, when absolute numbers of CD4+ T cells were restored to baseline levels. These CD4+ T cells showed a markedly skewed phenotype, however, as there were decreased levels of memory cells in CD8+ lymphocyte-depleted macaques compared to controls. In intestinal tissues and lymph nodes, we observed a significantly higher loss of CCR5+ CD45RA− CD4+ T cells in CD8+ lymphocyte-depleted macaques than in controls, suggesting that these SIV-targeted CD4+ T cells were eliminated more efficiently in CD8+ lymphocyte-depleted animals. Also, CD8+ lymphocyte depletion significantly affected the ability to generate SIV Gag-specific CD4+ T-cell responses and neutralizing antibodies. These results reemphasize that SIV-specific CD8+ T-cell responses are absolutely critical to initiate at least partial control of SIV infection.

scholarly journals Associations of Simian Immunodeficiency Virus (SIV)-Specific Follicular CD8+T Cells with Other Follicular T Cells Suggest Complex Contributions to SIV Viremia Control

2018 ◽  
Vol 200 (8) ◽  
pp. 2714-2726 ◽  
Author(s):  
Mohammad Arif Rahman ◽  
Katherine M. McKinnon ◽  
Tatiana S. Karpova ◽  
David A. Ball ◽  
David J. Venzon ◽  
...  
Keyword(s):  
T Cells ◽  
Simian Immunodeficiency Virus ◽  
Cd8 T Cells ◽  
Immunodeficiency Virus

scholarly journals Perforin Expression in the Gastrointestinal Mucosa Is Limited to Acute Simian Immunodeficiency Virus Infection

2006 ◽  
Vol 80 (6) ◽  
pp. 3083-3087 ◽  
Author(s):  
Máire F. Quigley ◽  
Kristina Abel ◽  
Bartek Zuber ◽  
Christopher J. Miller ◽  
Johan K. Sandberg ◽  
...  
Keyword(s):  
T Cells ◽  
Simian Immunodeficiency Virus ◽  
Cd8 T Cells ◽  
Positive Response ◽  
Rhesus Macaques ◽  
Gastrointestinal Mucosa ◽  
Immunodeficiency Virus ◽  
Siv Infection ◽  
Perforin Expression ◽  
Important Site

ABSTRACT Perforin-mediated cytotoxicity is a major effector function of virus-specific CD8 T cells. We have investigated the expression of perforin in the gut, an important site of simian immunodeficiency virus (SIV) pathogenesis, during experimental SIV infection of rhesus macaques. We observed significant increases in perforin protein and mRNA expression levels in the colons of SIV-infected macaques as early as 21 days after infection. However, during chronic infection, despite ongoing viral replication, perforin expression returned to levels similar to those detected in SIV-naïve animals. These findings demonstrate the presence of a robust perforin-positive response in gastrointestinal CD8 T cells during acute, but not chronic, SIV infection.

scholarly journals Rectal Acquisition of Simian Immunodeficiency Virus (SIV) SIVmac239 Infection despite Vaccine-Induced Immune Responses against the Entire SIV Proteome

2020 ◽  
Vol 94 (24) ◽  
Author(s):  
Mauricio A. Martins ◽  
Lucas Gonzalez-Nieto ◽  
Michael J. Ricciardi ◽  
Varian K. Bailey ◽  
Christine M. Dang ◽  
...  
Keyword(s):  
T Cells ◽  
Virus Infection ◽  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Vaccine Efficacy ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Hiv Vaccine ◽  
Partial Control ◽  
Immunodeficiency Virus

ABSTRACT Given the complex biology of human immunodeficiency virus (HIV) and its remarkable capacity to evade host immune responses, HIV vaccine efficacy may benefit from the induction of both humoral and cellular immune responses of maximal breadth, potency, and longevity. Guided by this rationale, we set out to develop an immunization protocol aimed at maximizing the induction of anti-Envelope (anti-Env) antibodies and CD8+ T cells targeting non-Env epitopes in rhesus macaques (RMs). Our approach was to deliver the entire simian immunodeficiency virus (SIV) proteome by serial vaccinations. To that end, 12 RMs were vaccinated over 81 weeks with DNA, modified vaccinia Ankara (MVA), vesicular stomatitis virus (VSV), adenovirus type 5 (Ad5), rhesus monkey rhadinovirus (RRV), and DNA again. Both the RRV and the final DNA boosters delivered a near-full-length SIVmac239 genome capable of assembling noninfectious SIV particles and inducing T-cell responses against all nine SIV proteins. Compared to previous SIV vaccine trials, the present DNA-MVA-VSV-Ad5-RRV-DNA regimen resulted in comparable levels of Env-binding antibodies and SIV-specific CD8+ T-cells. Interestingly, one vaccinee developed low titers of neutralizing antibodies (NAbs) against SIVmac239, a tier 3 virus. Following repeated intrarectal marginal-dose challenges with SIVmac239, vaccinees were not protected from SIV acquisition but manifested partial control of viremia. Strikingly, the animal with the low-titer vaccine-induced anti-SIVmac239 NAb response acquired infection after the first SIVmac239 exposure. Collectively, these results highlight the difficulties in eliciting protective immunity against immunodeficiency virus infection. IMPORTANCE Our results are relevant to HIV vaccine development efforts because they suggest that increasing the number of booster immunizations or delivering additional viral antigens may not necessarily improve vaccine efficacy against immunodeficiency virus infection.

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