title: Altered expression of the tetraspanin CD81 on B and T lymphocytes during HIV-1 infection.
abstract: CD81 is a member of the tetraspan superfamily and plays a role in immune responses and in hepatitis C virus (HCV) pathogenesis. We analysed CD81 cell surface and mRNA expression in different lymphocytic subpopulations in human immunodeficiency virus (HIV)-1, HCV and dually infected subjects. CD81 cell surface expression was evaluated with fluorescence activated cell sorter (FACS) analysis; mRNA quantification was performed with semiquantitative polymerase chain reaction (PCR). CD81 cell surface expression on CD4(+) T lymphocytes was significantly different by analysis of variance (anova) test (P < 0.001), with reduced expression in HIV-1(+) patients. In B lymphocytes, higher cell surface expression was present in HIV-1, in HCV and in dually infected subjects compared to healthy controls. CD81 expression on B lymphocytes showed a positive correlation with plasma HIV-RNA. CD81 mRNA levels in B lymphocytes were significantly higher in HIV-1(+) patients compared to healthy controls. The potential consequence of the down-regulation of CD81 in CD4(+) cells during HIV-1 infection in conjunction with diverted CD28, CD4 and CD3 expression is the disruption of T cell function. Increased CD81 expression on B lymphocytes might explain the higher prevalence of lymphoproliferative disorders in HIV-1 and HCV infection. Up-regulation of CD81 mRNA on CD4(+) T cells indicates that down-regulation of CD81 occurs at the post-transcriptional/translational level.
authors.affiliation: Department of Clinical Sciences Section of Infectious Diseases and Tropical Medicine, L. Sacco Hospital, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Meroni
authors.forename: L
authors.initials: L
authors.lastname: Milazzo
authors.forename: B
authors.initials: B
authors.lastname: Menzaghi
authors.forename: R
authors.initials: R
authors.lastname: Mazzucchelli
authors.forename: D
authors.initials: D
authors.lastname: Mologni
authors.forename: P
authors.initials: P
authors.lastname: Morelli
authors.forename: V
authors.initials: V
authors.lastname: Broggini
authors.forename: F
authors.initials: F
authors.lastname: Adorni
authors.forename: M
authors.initials: M
authors.lastname: Galli
authors.forename: A
authors.initials: A
authors.lastname: Riva
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015703:Antigens, CD / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D015658:HIV Infections / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D016174:Hepacivirus / Q000276:immunology; D006526:Hepatitis C / Q000276:immunology*; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D060225:Tetraspanin 28
chemical_list: D015703:Antigens, CD; C554798:CD81 protein, human; D012333:RNA, Messenger; D060225:Tetraspanin 28