Characterization of HIV-1 Gag-specific T cell responses in chronically infected Indian population

Clin Exp Immunol. 2005 Nov;142(2):388-97. doi: 10.1111/j.1365-2249.2005.02926.x.

Abstract

India is at the epicentre of the global HIV/AIDS epidemic in South-east Asia, predominated by subtype C infections. It is important to characterize HIV-1-specific T cell responses in this particular population with the aim of identifying protective correlates of immunity to control HIV-1 infection. In this study, we performed a comprehensive analysis of the breadth and magnitude of T cell responses directed at HIV-1 subtype C Gag, one of the most conserved HIV-1 proteins. The study population consisted of antiretroviral naive, chronic HIV-1 subtype C-infected individuals at various stages of infection. We used recent advanced techniques such as enzyme-linked immunospot (ELISPOT) assay and intracellular cytokine staining to quantify the total CD4(+) and CD8(+) T cell response to HIV-1 gag at single peptide level, regardless of HLA haplotype of the infected individual. The p24-Gag was identified as the most frequently recognized subunit protein with the greatest magnitude of CD4(+) and CD8(+) T cell responses. Stronger and broader CD8 T cell responses were recognized, contrasting with the weaker and narrower CD4 T cell responses with regard to Gag protein subunits. The magnitude of the HIV-specific interferon (IFN)-gamma responses was observed to be higher than the corresponding interleukin (IL)-2 response, indicating the persistence of antigenic load in chronically infected Indian population due to the probable dysfunction of HIV-specific, IFN-gamma-secreting CD8 T cells in absence of IL-2 help.

MeSH terms

  • Adult
  • Amino Acid Sequence
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Chronic Disease
  • Cytokines / biosynthesis
  • Enzyme-Linked Immunosorbent Assay / methods
  • Epitopes, B-Lymphocyte / genetics
  • Epitopes, B-Lymphocyte / immunology
  • Female
  • HIV Core Protein p24 / genetics
  • HIV Core Protein p24 / immunology*
  • HIV Infections / immunology*
  • HIV-1 / immunology*
  • Humans
  • Immunophenotyping
  • Lymphocyte Count
  • Male
  • Molecular Sequence Data
  • Peptide Fragments / immunology

Substances

  • Cytokines
  • Epitopes, B-Lymphocyte
  • HIV Core Protein p24
  • Peptide Fragments