B cell responses to HIV antigen are a potent correlate of viremia in HIV-1 infection and improve with PD-1 blockade

PLoS One. 2013 Dec 16;8(12):e84185. doi: 10.1371/journal.pone.0084185. eCollection 2013.

Abstract

Infection with Human Immunodeficiency Virus Type 1 (HIV-1) induces defects of both cellular and humoral immune responses. Impaired CD4+ T cell help and B cell dysfunction may partially explain the low frequency of broadly neutralizing antibodies in HIV-infected individuals. To understand the extent of B cell dysfunction during HIV infection, we assessed the level of B cell activation at baseline and after stimulation with a variety of antigens. Increased levels of viremia were associated with higher baseline expression of the activation marker CD86 on B cells and with decreased ability of B cells to increase expression of CD86 after in vitro stimulation with inactivated HIV-1. In a series of cell isolation experiments B cell responses to antigen were enhanced in the presence of autologous CD4+ T cells. HIV infected individuals had a higher frequency of PD-1 expression on B cells compared to HIV- subjects and PD-1 blockade improved B cell responsiveness to HIV antigen, suggesting that inhibitory molecule expression during HIV-1 infection may contribute to some of the observed B cell defects. Our findings demonstrate that during chronic HIV infection, B cells are activated and lose full capacity to respond to antigen, but suppression of inhibitory pressures as well as a robust CD4+ T cell response may help preserve B cell function.

Publication types

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

MeSH terms

  • B-Lymphocytes / immunology*
  • B-Lymphocytes / metabolism
  • B7-2 Antigen / metabolism
  • CD4 Lymphocyte Count
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism
  • HIV Antigens / immunology*
  • HIV Infections / immunology*
  • HIV Infections / metabolism
  • HIV Infections / virology*
  • HIV-1 / immunology*
  • Humans
  • Interleukin-2 Receptor alpha Subunit / metabolism
  • Lymphocyte Activation / immunology
  • Programmed Cell Death 1 Receptor / antagonists & inhibitors*
  • Programmed Cell Death 1 Receptor / immunology
  • Viral Load
  • Viremia / immunology*
  • Viremia / metabolism

Substances

  • B7-2 Antigen
  • HIV Antigens
  • Interleukin-2 Receptor alpha Subunit
  • Programmed Cell Death 1 Receptor