Dataset Information

Reactivation of simian immunodeficiency virus reservoirs in the brain of virally suppressed macaques.

ABSTRACT:

Objective

Resting CD4 T cells have been recognized as the major cell reservoir of latent HIV-1 during antiretroviral therapy (ART). Using an simian immunodeficiency virus (SIV)/macaque model for AIDS and HIV-related neurocognitive disorders we assessed the contribution of the brain to viral latency and reactivation.

Design

Pigtailed macaques were dual inoculated with SIVDeltaB670 and SIV17E-Fr and treated with an efficacious central nervous system-penetrant ART. After 500 days of viral suppression animals were treated with two cycles of latency reversing agents and increases in viral transcripts were examined.

Methods

Longitudinal plasma and cerebrospinal fluid (CSF) viral loads were analyzed by quantitative and digital droplet PCR. After necropsy, viral transcripts in organs were analyzed by PCR, in-situ hybridization, and phylogenetic genotyping based on env V1 loop sequences. Markers for neuronal damage and CSF activation were measured by ELISA.

Results

Increases in activation markers and plasma and CSF viral loads were observed in one animal treated with latency reversing agents, despite ongoing ART. SIV transcripts were identified in occipital cortex macrophages by in-situ hybridization and CD68 staining. The most abundant SIV genotype in CSF was unique and expanded independent from viruses found in the periphery.

Conclusion

The central nervous system harbors latent SIV genomes after long-term viral suppression by ART, indicating that the brain represents a potential viral reservoir and should be seriously considered during AIDS cure strategies.

SUBMITTER: Gama L

PROVIDER: S-EPMC5131686 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature

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Publications

Reactivation of simian immunodeficiency virus reservoirs in the brain of virally suppressed macaques.

Gama Lucio L Abreu Celina M CM Shirk Erin N EN Price Sarah L SL Li Ming M Laird Greg M GM Pate Kelly A Metcalf KA Wietgrefe Stephen W SW O'Connor Shelby L SL Pianowski Luiz L Haase Ashley T AT Van Lint Carine C Siliciano Robert F RF Clements Janice E JE

AIDS (London, England) 20170101 1

<h4>Objective</h4>Resting CD4 T cells have been recognized as the major cell reservoir of latent HIV-1 during antiretroviral therapy (ART). Using an simian immunodeficiency virus (SIV)/macaque model for AIDS and HIV-related neurocognitive disorders we assessed the contribution of the brain to viral latency and reactivation.<h4>Design</h4>Pigtailed macaques were dual inoculated with SIVDeltaB670 and SIV17E-Fr and treated with an efficacious central nervous system-penetrant ART. After 500 days of ...[more]

PMID: 27898590

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Project description:A human immunodeficiency virus (HIV) infection cure requires an understanding of the cellular and anatomical sites harboring virus that contribute to viral rebound upon treatment interruption. Despite antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) are reported in HIV-infected individuals on ART. Biomarkers for macrophage activation and neuronal damage in cerebrospinal fluid (CSF) of HIV-infected individuals demonstrate continued effects of HIV in brain and suggest that the central nervous system (CNS) may serve as a viral reservoir. Using a simian immunodeficiency virus (SIV)/macaque model for HIV encephalitis and AIDS, we evaluated whether infected cells persist in brain despite ART. Eight SIV-infected pig-tailed macaques were virally suppressed with ART, and plasma and CSF viremia levels were analyzed longitudinally. To assess whether virus persisted in brain macrophages (BrMΦ) in these macaques, we used a macrophage quantitative viral outgrowth assay (MΦ-QVOA), PCR, and in situ hybridization (ISH) to measure the frequency of infected cells and the levels of viral RNA and DNA in brain. Viral RNA in brain tissue of suppressed macaques was undetectable, although viral DNA was detected in all animals. The MΦ-QVOA demonstrated that the majority of suppressed animals contained latently infected BrMΦ. We also showed that virus produced in the MΦ-QVOAs was replication competent, suggesting that latently infected BrMΦ are capable of reestablishing productive infection upon treatment interruption. This report provides the first confirmation of the presence of replication-competent SIV in BrMΦ of ART-suppressed macaques and suggests that the highly debated issue of viral latency in macrophages, at least in brain, has been addressed in SIV-infected macaques treated with ART.IMPORTANCE Resting CD4+ T cells are currently the only cells that fit the definition of a latent reservoir. However, recent evidence suggests that HIV/SIV-infected macrophages persist despite ART. Markers of macrophage activation and neuronal damage are observed in the CSF of HIV-infected individuals and of SIV-infected macaques on suppressive ART regimens, suggesting that the CNS has continued virus infection and latent infection. A controversy exists as to whether brain macrophages represent a latent source of replication-competent virus capable of reestablishing infection upon treatment interruption. In this study, we demonstrated the presence of the latent macrophage reservoir in brains of SIV-infected ART-treated macaques and analyzed the reservoir using our established outgrowth assay to quantitate macrophages harboring replication-competent SIV genomes. Our results support the idea of the existence of other latent reservoirs in addition to resting CD4+ T cells and underscore the importance of macrophages in developing strategies to eradicate HIV.

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Dataset Information

Reactivation of simian immunodeficiency virus reservoirs in the brain of virally suppressed macaques.

Objective

Design

Methods

Results

Conclusion

Publications

Reactivation of simian immunodeficiency virus reservoirs in the brain of virally suppressed macaques.

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