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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

Keywords

Cell Activation Immune Activation Specific Immunity Treg Frequency Elite Controller 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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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