Differential effects of IL-21 and IL-15 on perforin expression, lysosomal degranulation, and proliferation in CD8 T cells of patients with human immunodeficiency virus-1 (HIV)

Blood. 2007 May 1;109(9):3873-80. doi: 10.1182/blood-2006-09-045278. Epub 2006 Dec 27.

Abstract

An urgent need exists to devise strategies to augment antiviral immune responses in patients with HIV who are virologically well controlled and immunologically stable on highly active antiretroviral therapy (HAART). The objective of this study was to compare the immunomodulatory effects of the cytokines interleukin (IL)-21 with IL-15 on CD8 T cells in patients with HIV RNA of less than 50 copies/mL and CD4 counts greater than 200 cells/mm.(3) Patient CD8 T cells displayed skewed maturation and decreased perforin expression compared with healthy controls. Culture of freshly isolated patient peripheral-blood mononuclear cells (PBMCs) for 5 hours to 5 days with IL-21 resulted in up-regulation of perforin in CD8 T cells, including memory and effector subsets and virus-specific T cells. IL-21 did not induce T-cell activation or proliferation, nor did it augment T-cell receptor (TCR)-induced degranulation. Treatment of patient PBMCs with IL-15 resulted in induction of perforin in association with lymphocyte proliferation and augmentation of TCR-induced degranulation. Patient CD8 T cells were more responsive to cytokine effects than the cells of healthy volunteers. We conclude that CD8 T cells of patients with HIV can be modulated by IL-21 to increase perforin expression without undergoing overt cellular activation. IL-21 could potentially be useful for its perforin-enhancing properties in anti-HIV immunotherapy.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Antiretroviral Therapy, Highly Active
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • Cell Degranulation / drug effects
  • Cell Degranulation / immunology
  • Cells, Cultured
  • Female
  • Gene Expression Regulation / drug effects*
  • Gene Expression Regulation / immunology
  • HIV Infections / immunology*
  • HIV Infections / metabolism
  • HIV Infections / therapy
  • HIV-1 / immunology*
  • Humans
  • Immunotherapy
  • Interleukin-15 / immunology
  • Interleukin-15 / pharmacology*
  • Interleukins / immunology
  • Interleukins / pharmacology*
  • Interleukins / therapeutic use
  • Lysosomes / immunology*
  • Lysosomes / metabolism
  • Male
  • Membrane Glycoproteins / biosynthesis
  • Membrane Glycoproteins / immunology*
  • Middle Aged
  • Perforin
  • Pore Forming Cytotoxic Proteins / biosynthesis
  • Pore Forming Cytotoxic Proteins / immunology*

Substances

  • Interleukin-15
  • Interleukins
  • Membrane Glycoproteins
  • Pore Forming Cytotoxic Proteins
  • Perforin
  • interleukin-21