title: Level, phenotype and activation status of CD4+FoxP3+ regulatory T cells in patients chronically infected with human immunodeficiency virus and/or hepatitis C virus.
abstract: CD4(+) regulatory T (T(reg)) cells have been involved in impaired immunity and persistence of viral infections. Herein, we report the level, phenotype and activation status of T(reg) cells in patients chronically infected with human immunodeficiency virus (HIV) and/or hepatitis C virus (HCV). Expression of CD25, CD45RA, CD27, CD127 and CD38 was assessed on these cells using polychromatic flow cytometry in 20 healthy controls, 20 HIV-monoinfected, 20 HCV-monoinfected and 31 HIV/HCV-co-infected patients. T(reg) cells were defined as CD4(+)forkhead box P3 (FoxP3)(+). The percentage of T(reg) cells was increased significantly in HIV patients compared with controls. Moreover, there was a significant inverse correlation between CD4 counts and T(reg) cell levels. Fewer than 50% of T(reg) cells expressed CD25, with differences in terms of CD127 expression between CD25(+) and CD25((-)) T(reg) cells. CD4(+)Foxp3(+) T(reg) cells displayed predominantly a central memory phenotype (CD45RA(-)CD27(+)), without differences between patients and healthy controls. Activated T(reg) cells were increased in HIV patients, particularly considering the central memory subset. In summary, HIV infection, but not HCV, induces an up-regulation of highly activated T(reg) cells, which increases in parallel with CD4 depletion. Hypothetically, this might contribute to the accelerated course of HCV-related liver disease in HIV-immunosuppressed patients.
authors.affiliation: Department of Infectious Diseases, Hospital Carlos III, 28029 Madrid, Spain.
authors.forename: N I
authors.initials: NI
authors.lastname: Rallón
authors.forename: M
authors.initials: M
authors.lastname: López
authors.forename: V
authors.initials: V
authors.lastname: Soriano
authors.forename: J
authors.initials: J
authors.lastname: García-Samaniego
authors.forename: M
authors.initials: M
authors.lastname: Romero
authors.forename: P
authors.initials: P
authors.lastname: Labarga
authors.forename: P
authors.initials: P
authors.lastname: García-Gasco
authors.forename: J
authors.initials: J
authors.lastname: González-Lahoz
authors.forename: J M
authors.initials: JM
authors.lastname: Benito
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000032:analysis*; D006678:HIV; D015658:HIV Infections / Q000276:immunology*; D016174:Hepacivirus; D019698:Hepatitis C, Chronic / Q000276:immunology*; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D053699:Interleukin-7 Receptor alpha Subunit / Q000032:analysis; D008213:Lymphocyte Activation; D010641:Phenotype; D018709:Statistics, Nonparametric; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D055815:Young Adult
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D053699:Interleukin-7 Receptor alpha Subunit