Cerebrospinal fluid (CSF) CD8+ T-cells that express interferon-gamma contribute to HIV associated neurocognitive disorders (HAND).
<h4>Background</h4>HIV associated neurocognitive disorders (HAND) continue to affect cognition and everyday functioning despite anti-retroviral treatment (ART). Previous studies focused on mechanisms related to monocyte/macrophage mediated inflammation. However, in the ART era, there is...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2015-01-01
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| Series: | PLoS ONE |
| Online Access: | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0116526&type=printable |
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| Summary: | <h4>Background</h4>HIV associated neurocognitive disorders (HAND) continue to affect cognition and everyday functioning despite anti-retroviral treatment (ART). Previous studies focused on mechanisms related to monocyte/macrophage mediated inflammation. However, in the ART era, there is increasing evidence for the involvement of CD8+ T-cells in CNS pathogenesis.<h4>Methods</h4>To investigate the relationship between T-cell responses and neurocognitive impairment (NCI), cerebrospinal fluid (CSF) and peripheral blood CD4+ and CD8+ T-cell intracellular cytokine (IFNγ, IL-2, TNFα) and lytic marker (CD107a) expression were assessed in HIV infected subjects who underwent comprehensive neurocognitive (NC) evaluation and either initiated or changed ART.<h4>Results</h4>Data were collected from 31 participants at 70 visits. The frequency of cytokine expressing T-cells in CSF was significantly higher than in peripheral blood for CD4+T-cells: TNFα, IL-2, IFNγ and CD8+T-cells: IL-2 and IFNγ. Analysis of T-cell activity and NCI as a function of CSF HIV RNA levels suggested a general association between NCI, high CSF CD8+ (but not CD4+T-cell) cytokine expression and CSF HIV RNA <103 copies/ml (p<0.0001). Specifically, CSF CD8+ T-cell IFNγ expression correlated with severity of NCI (r = 0.57, p = 0.004). Multivariable analyses indicated that CSF CD8+T-cell IFNγ and myeloid activation (CD163) contributed equally and independently to cognitive status and a composite variable produced the strongest correlation with NCI (r = 0.83, p = 0.0001). In contrast, CD8+ cytolytic activity (CD107a expression) was negatively correlated with NCI (p = 0.05) but was dependent on CD4 levels >400/μl and low CSF HIV RNA levels (<103 copies/ml). In our longitudinal analysis of 16 subjects, higher CSF CD8+IFNγ expression at baseline predicted NC decline at follow-up (p = 0.02). Severity of NCI at follow-up correlated with level of residual HIV RNA in CSF.<h4>Conclusions</h4>Presence of IFNγ expressing CD8+ T-cells, absence of cytolytic CD8+ T-cells, high myeloid activation, and failure of ART to suppress HIV replication in CSF contribute to increased risk of HAND. |
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| ISSN: | 1932-6203 |