title: Study of CD4+CD8+ double positive T-lymphocyte phenotype and function in Indian patients infected with HIV-1.
abstract: CD4+CD8+ double positive T cells represent a minor peripheral blood lymphocyte population. CD4+ expression on CD8+ T cells is induced following cellular activation, and as chronic HIV-1 infection is associated with generalized immune activation, double positive T cells studies have become necessary to understand the immunopathology of human immunodeficiency virus (HIV). The frequency of double positive T cells in persons infected with HIV was studied in comparison to uninfected controls. Further, the expression of CD38, HLA-DR, and programmed death (PD)-1 on these cells were ascertained. HIV-1 specific double positive T cells were also studied for their cytokine secretory ability and phenotype. A significantly higher double positive cell population was observed in the patients with advanced HIV disease (CD4+ T cell counts below 200 cells/µl), as compared to patients with CD4+ T cell counts above 500 cells/µl. Double positive T cells from patients with symptomatic HIV disease had a significantly increased activation and exhaustion levels, compared to asymptomatic subjects and to single positive T cells from the same subjects. HIV-1 specific double positive T cells showed further increase in CD38 and PD-1 expression levels. The proportion of CD38 and PD-1 expressing total and HIV-1 specific double positive T cells correlated positively with HIV-1 plasma viremia and negatively with CD4+ T cell counts. HIV infection results in a marked increase of double positive T cell population, and this cell population shows higher level of activation and exhaustion (increased PD-1 expression) compared to the single positive CD4+ and CD8+ T cells.
authors.affiliation: Department of Microbiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
authors.forename: Neeraj K
authors.initials: NK
authors.lastname: Chauhan
authors.forename: Madhu
authors.initials: M
authors.lastname: Vajpayee
authors.forename: Kamalika
authors.initials: K
authors.lastname: Mojumdar
authors.forename: Ravinder
authors.initials: R
authors.lastname: Singh
authors.forename: Alpana
authors.initials: A
authors.lastname: Singh
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000032:analysis; D000328:Adult; D015704:CD4 Antigens / Q000032:analysis*; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D005260:Female; D015658:HIV Infections / Q000276:immunology* / Q000473:pathology / Q000821:virology; D015497:HIV-1 / Q000276:immunology* / Q000302:isolation & purification; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D016130:Immunophenotyping; D007194:India; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis; D008875:Middle Aged; D061026:Programmed Cell Death 1 Receptor / Q000032:analysis
chemical_list: D015704:CD4 Antigens; D016207:Cytokines; D006684:HLA-DR Antigens; D008562:Membrane Glycoproteins; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1