title: Phenotypic characterization of lymphocytes in HCV/HIV co-infected patients.
abstract: While hepatitis C virus (HCV)-specific immune responses are attenuated in HCV/HIV co-infected patients compared to those infected with HCV alone, the reasons for this remain unclear. In this study, the proportions of regulatory, naïve, and memory T cells, along with chemokine receptor expression, were measured in co-infected and mono-infected patients to determine if there is an alteration in the phenotypic profile of lymphocytes in these patients. HCV/HIV co-infected patients had increased proportions of CD4(+) naïve cells and decreased proportions of CD4(+) effector cells when compared to HCV mono-infected patients. The proportions of CD4(+) Tregs and CD4(+) CXCR3(+) T cells were also significantly lower in co-infected patients. A decrease in CD4(+) Tregs and subsequent loss of immunosuppressive function may contribute to the accelerated progression to liver disease in co-infected individuals. Dysregulation of immune responses following reduction in the proportions of CD4(+) CXCR3(+) Th-1 cells may contribute to the reduced functional capacity of HCV-specific immune responses in co-infected patients. The findings of this study provide new information on the T-cell immunophenotype in HCV/HIV co-infected patients when compared to those infected with HCV alone, and may provide insight into why cell-mediated immune responses are diminished during HCV infection.
authors.affiliation: Centre for Research in Infectious Diseases, University College Dublin, Ireland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Roe
authors.forename: Suzie
authors.initials: S
authors.lastname: Coughlan
authors.forename: Jonathan
authors.initials: J
authors.lastname: Dean
authors.forename: John S
authors.initials: JS
authors.lastname: Lambert
authors.forename: Shay
authors.initials: S
authors.lastname: Keating
authors.forename: Suzanne
authors.initials: S
authors.lastname: Norris
authors.forename: Colm
authors.initials: C
authors.lastname: Bergin
authors.forename: William W
authors.initials: WW
authors.lastname: Hall
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000276:immunology* / Q000472:pathogenicity; D016174:Hepacivirus / Q000276:immunology* / Q000472:pathogenicity; D006526:Hepatitis C / Q000150:complications* / Q000276:immunology / Q000821:virology; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D055815:Young Adult