Regulatory T cells and chronic immune activation in human immunodeficiency virus 1 (HIV-1)-infected children

R. Freguja, K. Gianesin, I. Mosconi, M. Zanchetta, F. Carmona, O. Rampon, C. Giaquinto, A. De Rossi

Research output: Contribution to journalArticle

Abstract

Summary: The function of CD4 + T cells with regulatory activity (T regs) is the down-regulation of immune responses. This suppressive activity may limit the magnitude of effector responses, resulting in failure to control human immunodeficiency virus 1 (HIV-1) infection, but may also suppress chronic immune activation, a characteristic feature of HIV-1 disease. We evaluated the correlation between viral load, immune activation and T regs in HIV-1-infected children. Eighty-nine HIV-1-infected children (aged 6-14 years) were included in the study and analysed for HIV-1 plasmaviraemia, HIV-1 DNA load, CD4 and CD8 cell subsets. T reg cells [CD4 + CD25 highCD127 lowforkhead box P3 (FoxP3 high)] and CD8-activated T cells (CD8 +CD38 +) were determined by flow cytometry. Results showed that the number of activated CD8 +CD38 + T cells increased in relation to HIV-1 RNA plasmaviraemia (r=0·403, Pregs also correlated positively with HIV-1 plasmaviraemia (r=0·323, P=0·002), but correlated inversely with CD4 + cells (r=-0·312, P=0·004), thus suggesting a selective expansion along with increased viraemia and CD4 + depletion. Interestingly, a positive correlation was found between the levels of T regs and CD8 +CD38 + T cells (r=0·305, P=0·005), and the percentage of T regs tended to correlate with HIV-1 DNA load (r=0·224, P=0·062). Overall, these findings suggest that immune activation contributes to the expansion of T reg cells. In turn, the suppressive activity of T regs may impair effector responses against HIV-1, but appears to be ineffective in limiting immune activation.

Original languageEnglish
Pages (from-to)373-380
Number of pages8
JournalClinical and Experimental Immunology
Volume164
Issue number3
DOIs
Publication statusPublished - Jun 2011

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Keywords

  • Flow cytometry
  • HIV-1-infected children
  • Immune activation
  • T
  • Viral load

ASJC Scopus subject areas

  • Immunology
  • Immunology and Allergy

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