title: A CD3+CD8+ T cell population lacking CD5 antigen expression is expanded in peripheral blood of human immunodeficiency virus-infected patients.
abstract: In this study we analyzed the behavior of a CD3+ T cell subpopulation lacking CD5 antigen expression in PBMC from HIV-1-infected patients. CD3+CD5- lymphocytes were greatly increased in peripheral blood of HIV-1+ patients, accounting for 20.6 +/- 9.9% of the total CD3+ cells, compared to seronegative individuals (5.5 +/- 3.2%). In both seropositive patients and controls, CD3+CD5- cells belonged to the CD8+ compartment; they were nonactivated, TCR alpha/beta+, naive lymphocytes, and in seronegative individuals preferentially expressed NK cell-associated markers, such as CD11b, CD16, CD56, and CD57. The phenotypic profile of this subset was slightly different in seropositive patients; while TCR expression and CD45RA/RO profile were comparable, CD11b and CD16 expression was lower compared to control figures, while CD56 expression was not changed, and CD57 expression was enhanced. Functional analysis of enriched CD3+CD8+CD5- cells showed an impaired ability to proliferate in response to mitogenic and antigenic stimuli; despite their NK-like phenotype, CD3+CD8+CD5- cells did not exert any NK cytotoxic activity, and only a lectin-dependent cytotoxic potential could be evidenced in this population. These results describe a novel alteration in the lymphocytes phenotypic profile during HIV-1 infection, involving a "transitional" population, which shares some properties of the T and of the NK cell lineage.
authors.affiliation: Institute of Oncology, University of Padua, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Indraccolo
authors.forename: M
authors.initials: M
authors.lastname: Mion
authors.forename: R
authors.initials: R
authors.lastname: Zamarchi
authors.forename: V
authors.initials: V
authors.lastname: Coppola
authors.forename: F
authors.initials: F
authors.lastname: Calderazzo
authors.forename: A
authors.initials: A
authors.lastname: Amadori
authors.forename: L
authors.initials: L
authors.lastname: Chieco-Bianchi
mesh_terms: D015415:Biomarkers / Q000032:analysis; D017252:CD3 Complex / Q000032:analysis*; D018956:CD5 Antigens / Q000032:analysis*; D016827:CD8 Antigens / Q000032:analysis*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D015415:Biomarkers; D017252:CD3 Complex; D018956:CD5 Antigens; D016827:CD8 Antigens