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

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.

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Expansion of Simian Immunodeficiency Virus (SIV)-Specific CD8 T Cell Lines from SIV-Naive Mauritian Cynomolgus Macaques for Adoptive Transfer

Journal of Virology ◽

10.1128/jvi.00993-15 ◽

2015 ◽

Vol 89 (19) ◽

pp. 9748-9757 ◽

Cited By ~ 8

Author(s):

Mariel S. Mohns ◽

Justin M. Greene ◽

Brian T. Cain ◽

Ngoc H. Pham ◽

Emma Gostick ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Simian Immunodeficiency Virus ◽

Cell Lines ◽

Cd8 T Cells ◽

Adoptive Transfer ◽

Cd8 T Cell ◽

Immunodeficiency Virus ◽

Cynomolgus Macaques ◽

Transfer Strategies

ABSTRACTCD8 T cells play a crucial role in the control of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). However, the specific qualities and characteristics of an effective CD8 T cell response remain unclear. Although targeting breadth, cross-reactivity, polyfunctionality, avidity, and specificity are correlated with HIV control, further investigation is needed to determine the precise contributions of these various attributes to CD8 T cell efficacy. We developed protocols for isolating and expanding SIV-specific CD8 T cells from SIV-naive Mauritian cynomolgus macaques (MCM). These cells exhibited an effector memory phenotype, produced cytokines in response to cognate antigen, and suppressed viral replicationin vitro. We further cultured cell lines specific for four SIV-derived epitopes, Nef103–111RM9, Gag389–394GW9, Env338–346RF9, and Nef254–262LT9. These cell lines were up to 94.4% pure, as determined by major histocompatibility complex (MHC) tetramer analysis. After autologous transfer into two MCM recipients, expanded CD8 T cells persisted in peripheral blood and lung tissue for at least 24 weeks and trafficked to multiple extralymphoid tissues. However, these cells did not impact the acute-phase SIV load after challenge compared to historic controls. The expansion and autologous transfer of SIV-specific T cells into naive animals provide a unique model for exploring cellular immunity and the control of SIV infection and facilitate a systematic evaluation of therapeutic adoptive transfer strategies for eradication of the latent reservoir.IMPORTANCECD8 T cells play a crucial role in the control of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). Autologous adoptive transfer studies followed by SIV challenge may help define the critical elements of an effective T cell response to HIV and SIV infection. We developed protocols for isolating and expanding SIV-specific CD8 T cells from SIV-naive Mauritian cynomolgus macaques. This is an important first step toward the development of autologous transfer strategies to explore cellular immunity and potential therapeutic applications in the SIV model.

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Effects of in Vivo Cd8+ T Cell Depletion on Virus Replication in Rhesus Macaques Immunized with a Live, Attenuated Simian Immunodeficiency Virus Vaccine

Journal of Experimental Medicine ◽

10.1084/jem.191.11.1921 ◽

1999 ◽

Vol 191 (11) ◽

pp. 1921-1932 ◽

Cited By ~ 112

Author(s):

Karin J. Metzner ◽

Xia Jin ◽

Fred V. Lee ◽

Agegnehu Gettie ◽

Daniel E. Bauer ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Simian Immunodeficiency Virus ◽

Cd8 T Cells ◽

Rhesus Macaques ◽

Cd8 T Cell ◽

T Cell Depletion ◽

Challenge Virus ◽

Immunodeficiency Virus

The role of CD8+ T lymphocytes in controlling replication of live, attenuated simian immunodeficiency virus (SIV) was investigated as part of a vaccine study to examine the correlates of protection in the SIV/rhesus macaque model. Rhesus macaques immunized for >2 yr with nef-deleted SIV (SIVmac239Δnef) and protected from challenge with pathogenic SIVmac251 were treated with anti-CD8 antibody (OKT8F) to deplete CD8+ T cells in vivo. The effects of CD8 depletion on viral load were measured using a novel quantitative assay based on real-time polymerase chain reaction using molecular beacons. This assay allows simultaneous detection of both the vaccine strain and the challenge virus in the same sample, enabling direct quantification of changes in each viral population. Our results show that CD8+ T cells were depleted within 1 h after administration of OKT8F, and were reduced by as much as 99% in the peripheral blood. CD8+ T cell depletion was associated with a 1–2 log increase in SIVmac239Δnef plasma viremia. Control of SIVmac239Δnef replication was temporally associated with the recovery of CD8+ T cells between days 8 and 10. The challenge virus, SIVmac251, was not detectable in either the plasma or lymph nodes after depletion of CD8+ T cells. Overall, our results indicate that CD8+ T cells play an important role in controlling replication of live, attenuated SIV in vivo.

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