Human immunodeficiency virus (HIV-1) infection selectively downregulates PD-1 expression in infected cells and protects the cells from early apoptosis in vitro and in vivo

Virology. 2008 Jun 20;376(1):140-53. doi: 10.1016/j.virol.2008.03.015. Epub 2008 Apr 25.

Abstract

Programmed Death-1 (PD-1), a member of T cell costimulatory molecules is expressed in high levels on antigen specific T cells during chronic viral infection, whereas PD-1 expression in the context of HIV-1 infected CD4+ T cells is not known. Here we report that productively infected CD4+ T cells lose PD-1, whereas bystander cells were unaffected. Additionally, p24+/PD-1 negative cells are less susceptible to apoptosis compared to bystander cells in the same infected milieu. Similar results were observed in vivo, as infected T cells isolated from HIV-1+ individuals have significantly low level of PD-1 and the observed loss of PD-1 in vivo is independent of viral load, CD4 count, and/or antiviral treatment. Together these results indicate that productively infected cells are resistant to early apoptosis by downregulating PD-1, whereas PD-1 enhances the susceptibility of effector T cells to apoptosis suggesting a dual role for PD-1 during HIV-1 infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Anti-Retroviral Agents / therapeutic use
  • Antigens, CD
  • Apoptosis Regulatory Proteins / antagonists & inhibitors*
  • Apoptosis*
  • CD4 Lymphocyte Count
  • CD4-Positive T-Lymphocytes / chemistry
  • CD4-Positive T-Lymphocytes / virology*
  • HIV Core Protein p24 / analysis
  • HIV Infections / drug therapy
  • HIV Infections / immunology
  • HIV-1 / immunology*
  • Humans
  • Programmed Cell Death 1 Receptor
  • Viral Load

Substances

  • Anti-Retroviral Agents
  • Antigens, CD
  • Apoptosis Regulatory Proteins
  • HIV Core Protein p24
  • PDCD1 protein, human
  • Programmed Cell Death 1 Receptor