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  • Poster presentation
  • Open Access

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

  • 1,
  • 1,
  • 1,
  • 2,
  • 3 and
  • 1Email author
Retrovirology20052 (Suppl 1) :P154

  • Published:


  • Maturation Stage
  • Central Memory
  • Infected Subject
  • Cell Immune Function
  • Selective Regulation


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.


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.


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.


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.


Authors’ Affiliations

Departments of Microbiology and Immunology, Miller School of Medicine Miami, FL, USA
Medicine, University of Miami, Miller School of Medicine Miami, FL, USA
Zymogenetics, Inc., Seattle, WA, USA


© The Author(s) 2005