Detection of HIV type 1 gag-specific CD4(+) T cell responses in acutely infected infants

AIDS Res Hum Retroviruses. 2008 Feb;24(2):265-70. doi: 10.1089/aid.2007.0096.

Abstract

Multiple HIV-1-specific cytokine and proliferative responses by CD4(+) T cells have not been studied in acutely infected infants. Using an intracellular cytokine staining assay, 34 untreated clade C HIV-1-infected infants (2-102 days old) were assessed for IFN-gamma, 28/34 for IL-2, and 26/34 for TNF-alpha responses to all HIV-1 proteins. Responses were detected in 29%, 36%, and 15% of infants, respectively. Twelve of the original 34 infants were then studied longitudinally for 14 months to determine the effect of viral load on IFN-gamma Gag-specific responses: seven infants were treated for 1 year, stopped treatment, and resumed when CD4% was < 20 and five infants were treated only when the CD4% was <20. Following treatment cessation, there was an immediate increase in viral load followed by an increase in the magnitude of CD4(+) Gag-specific responses. Despite this, the majority of infants (54%) had to restart treatment by 24 months of age, indicating that the immune responses were antigen driven but not associated with protection. Among untreated infants HIV-specific CD4(+) responses were detected sporadically indicating a dysfunctional immune response in the face of constant exposure to high levels of viremia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4 Lymphocyte Count
  • CD4-Positive T-Lymphocytes / immunology*
  • Cell Proliferation
  • Cells, Cultured
  • HIV Infections / immunology*
  • HIV-1 / immunology*
  • Humans
  • Infant
  • Interferon-gamma / biosynthesis
  • Interleukin-2 / biosynthesis
  • Longitudinal Studies
  • Tumor Necrosis Factor-alpha / biosynthesis
  • Viral Load
  • gag Gene Products, Human Immunodeficiency Virus / immunology*

Substances

  • Interleukin-2
  • Tumor Necrosis Factor-alpha
  • gag Gene Products, Human Immunodeficiency Virus
  • gag protein p1, Human immunodeficiency virus
  • Interferon-gamma