Retrovirology

, 6:P247 | Cite as

P16-18. Regulatory T cell frequencies correlate with T cell activation in chronic HIV-1 infection

  • M Angin
  • H Streeck
  • F Wen
  • A Pyo
  • A Trocha
  • I Toth
  • D Kwon
  • F Pereyra
  • G Alter
  • M Altfeld
  • BD Walker
  • MM Addo
Open Access
Poster presentation
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Keywords

Cell Activation Immune Activation Specific Immunity Treg Frequency Elite Controller 

Background

Regulatory T cells (Tregs) are potent modulators of immunity and may have an impact on T cell regulation and activation in the setting of HIV-1 infection. However, studies on Tregs in HIV-1 infection have shown divergent results and the exact role of Tregs in HIV-1 infection remains poorly understood. We here investigated Treg frequencies, immune activation and HIV-1 specific immunity in elite controllers (EC) and chronic progressors.

Methods

We studied the frequency of CD4+CD25+FoxP3+ Tregs in 16 HIV-1 elite controllers (HIV-RNA <50 copies/ml), 17 individuals with untreated chronic progressive HIV-1 infection and 9 HIV negative individuals by flowcytometric analysis. We also evaluated T cell activation by measurement of CD38 and HLA-DR expression on CD8 and CD4 T lymphocytes. HIV-1 specific CD8 T cell responses were available for a subset of individuals.

Results

In concordance with previous data, EC had significantly lower immune activation than chronic progressors (p < 0.005). The frequency of CD4+CD25+FoxP3+ regulatory T cells was positively correlated with T cell activation as measured by frequency of CD8+CD38+ T cells (R2 0.42, P = 0.006). There was a strong trend to decreased Treg frequencies in elite controllers and HIV negative individuals compared to chronic progressors. In the elite controller subset HLA-B57 positive EC had lower Treg frequencies than non-HLA-B57 EC, but this trend did not reach statistical significance.

Conclusion

Our data suggest that Treg frequencies positively correlate with immune activation in this cohort of individuals with chronic HIV-1 infection and that elite control is associated with lower T cell activation as previously described. Treg frequencies may be lower in HIV-1 elite controllers compared to chronic progressors but further studies are needed to investigate this finding in more detail and to address the impact of Tregs on HIV-1 specific T cell responses.

Copyright information

© Angin et al; licensee BioMed Central Ltd. 2009

This article is published under license to BioMed Central Ltd.

Authors and Affiliations

  • M Angin
    • 1
  • H Streeck
    • 1
  • F Wen
    • 1
  • A Pyo
    • 1
  • A Trocha
    • 1
  • I Toth
    • 1
  • D Kwon
    • 1
  • F Pereyra
    • 1
  • G Alter
    • 1
  • M Altfeld
    • 1
  • BD Walker
    • 1
  • MM Addo
    • 1
  1. 1.Ragon Institute of MGH, MIT and HarvardBostonUSA

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