title: Increased level of arginase activity correlates with disease severity in HIV-seropositive patients.
abstract: Infection with human immunodeficiency virus (HIV) results in a chronic infection that progressively impairs the immune system. Although depletion of CD4(+) T cells is frequently used to explain immunosuppression, chronicity of infection and progressive loss of CD4(+) T cells are not sufficient to fully account for immune dysregulation. Arginase-induced l-arginine deprivation is emerging as a key mechanism for the down-regulation of immune responses. Here, we hypothesized that the level of arginase activity increases with disease severity in HIV-seropositive patients. We determined the levels of arginase activity in peripheral blood mononuclear cells from HIV-seropositive patients and uninfected control participants. Our results show that peripheral blood mononuclear cells from HIV-seropositive patients with low CD4(+) T cell counts expressed statistically significantly higher levels of arginase activity, compared with patients with high CD4(+) T cell counts or uninfected control participants. Furthermore, we found a statistically significant correlation between high level of arginase activity and high viral load in HIV-seropositive patients.
authors.affiliation: Department of Immunology, Faculty of Medicine, Imperial College London, London, United Kingdom.
authors.forename: T E
authors.initials: TE
authors.lastname: Cloke
authors.forename: L
authors.initials: L
authors.lastname: Garvey
authors.forename: B-S
authors.initials: BS
authors.lastname: Choi
authors.forename: T
authors.initials: T
authors.lastname: Abebe
authors.forename: A
authors.initials: A
authors.lastname: Hailu
authors.forename: M
authors.initials: M
authors.lastname: Hancock
authors.forename: U
authors.initials: U
authors.lastname: Kadolsky
authors.forename: C R M
authors.initials: CR
authors.lastname: Bangham
authors.forename: M
authors.initials: M
authors.lastname: Munder
authors.forename: I
authors.initials: I
authors.lastname: Müller
authors.forename: G P
authors.initials: GP
authors.lastname: Taylor
authors.forename: P
authors.initials: P
authors.lastname: Kropf
mesh_terms: D000328:Adult; D001119:Arginase / Q000378:metabolism*; D018791:CD4 Lymphocyte Count; D002478:Cells, Cultured; D005260:Female; D006678:HIV / Q000302:isolation & purification; D015658:HIV Infections / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D019562:Viral Load
chemical_list: D001119:Arginase