title: Characterization of HIV-1 Gag-specific T cell responses in chronically infected Indian population.
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.
authors.affiliation: Department of Microbiology, All India Institute of Medical Sciences, New Delhi.
authors.forename: S
authors.initials: S
authors.lastname: Kaushik
authors.forename: M
authors.initials: M
authors.lastname: Vajpayee
authors.forename: N
authors.initials: N
authors.lastname: Wig
authors.forename: P
authors.initials: P
authors.lastname: Seth
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002908:Chronic Disease; D016207:Cytokines / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018985:Epitopes, B-Lymphocyte / Q000235:genetics / Q000276:immunology; D005260:Female; D016655:HIV Core Protein p24 / Q000235:genetics / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D018655:Lymphocyte Count; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology
chemical_list: D016207:Cytokines; D018985:Epitopes, B-Lymphocyte; D016655:HIV Core Protein p24; D010446:Peptide Fragments