Volume 2 Supplement 1

2005 International Meeting of The Institute of Human Virology

Open Access

Selective Regulation of CD8 T Cell Immune Function by IL-21 in HIV Infected Individuals

  • Subramaniam Krishnan1,
  • Natasa Strbo1,
  • Lesley White1,
  • Michael Kolber2,
  • Wayne Kindsvogel3 and
  • Savita Pahwa1Email author
Retrovirology20052(Suppl 1):P154

https://doi.org/10.1186/1742-4690-2-S1-P154

Published: 8 December 2005

Background

HIV infection is associated with skewed maturation of CD8 T cells, accumulation of cells in pre-effector stages and impaired effector function. Two g-chain signaling cytokines, IL-21 and IL-15, are known to enhance IFN-g in antigen-specific CD8T cells in humans and murine models and to synergize with each other. This study investigated IL-21 effects on CD8 T cells of HIV infected subjects.

Methods

Fresh peripheral blood mononuclear cells of healthy donors (n = 7) and HIV+ patients (n = 10, CD>4200 mm3, VL<200 copies/ml) were cultured for 5 days with IL-21 (50 ng/ml) or IL-15 (50 ng/ml) and analyzed for the expression of intracellular perforin and cellular proliferation (CFSE-dye dilution) in maturation subsets of CD8 T cells based on expression of CD45RA/CD62L.

Results

By itself, IL-21 addition significantly increased perforin, particularly in effector memory (EM) CD8 T cells (62% ± 8 vs 27% ± 7) and proliferation of this subset (10% ± 3 vs 0.5% ± 0.1) only in HIV subjects. In contrast, IL-15 upregulated perforin in central memory and EM CD8 T cells and induced proliferation in all CD8 maturation stages in all subjects.

Conclusion

IL-21 selectively augments EM CD8 T cell proliferation and perforin in HIV+ individuals, whereas IL-15 induces pan CD8 T cell activation in both, healthy and HIV+ individuals. The EM CD8 T cells of HIV+ patients are more responsive to IL-21 than healthy control cells.

Notes

Authors’ Affiliations

(1)
Departments of Microbiology and Immunology, Miller School of Medicine Miami
(2)
Medicine, University of Miami, Miller School of Medicine Miami
(3)
Zymogenetics, Inc.

Copyright

© The Author(s) 2005

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