Cutting edge: Prolonged exposure to HIV reinforces a poised epigenetic program for PD-1 expression in virus-specific CD8 T cells

J Immunol. 2013 Jul 15;191(2):540-4. doi: 10.4049/jimmunol.1203161. Epub 2013 Jun 14.

Abstract

Ag-specific CD8 T cells play a critical role in controlling HIV infection but eventually lose antiviral functions in part because of expression and signaling through the inhibitory programmed death-1 (PD-1) receptor. To better understand the impact of prolonged TCR ligation on regulation of PD-1 expression in HIV-specific CD8 T cells, we investigated the capacity of virus-specific CD8 T cells to modify the PD-1 epigenetic program after reduction in viral load. We observed that the transcriptional regulatory region was unmethylated in the PD-1(hi) HIV-specific CD8 T cells, whereas it remained methylated in donor-matched naive cells at acute and chronic stages of infection. Surprisingly, the PD-1 promoter remained unmethylated in HIV-specific CD8 T cells from subjects with a viral load controlled by antiviral therapy for >2 y or from elite controllers. Together, these data demonstrate that the epigenetic program at the PD-1 locus becomes fixed after prolonged exposure to HIV virus.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antiretroviral Therapy, Highly Active
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • DNA Methylation*
  • HIV Infections / drug therapy
  • HIV Infections / immunology*
  • HIV Infections / virology
  • HIV-1 / immunology
  • Humans
  • Programmed Cell Death 1 Receptor / genetics*
  • Programmed Cell Death 1 Receptor / metabolism*
  • Promoter Regions, Genetic
  • Transcription, Genetic
  • Viral Load

Substances

  • PDCD1 protein, human
  • Programmed Cell Death 1 Receptor