title: Novel inhibitory effects of gamma-glutamylcysteine ethyl ester against human immunodeficiency virus type 1 production and propagation.
abstract: The anti-human immunodeficiency virus type I (anti-HIV-1) effects of gamma-glutamylcysteine ethyl ester (gamma-GCE; TEI-2306) were examined in vitro. In initial studies using a vigorously HIV-1-producing human T-lymphocytic cell line, gamma-GCE displayed a novel biphasic repressive effect on chronic HIV-1 infection that was unlike that of other glutathione prodrugs or other reported antioxidants. In high doses, up to a concentration of 2.5 mM, at which neither glutathione (GSH) nor another GSH precursor has shown inhibitory effects, gamma-GCE potently inhibited the production of HIV-1 by a selective cytopathic effect against infected cells, while the viability and growth of uninfected cells were unaffected at the same gamma-GCE concentrations. At lower concentrations (200 to 400 microM), gamma-GCE significantly repressed the virus production from chronically HIV-1-expressing cells without affecting their viability. The discrepancy of the thresholds of the toxic doses between infected and uninfected cells was found to be more than 10-fold. Relatively high doses of gamma-GCE, utilized in acute HIV-1 infection of T-lymphocytic cells, entirely blocked the propagation of HIV-1 and rescued the cells from HIV-1-induced cell death. Furthermore, gamma-GCE at such concentrations was found to directly inhibit the infectivity of HIV-1 within 4 h. Repressive effects of gamma-GCE on acute HIV-1 infection in human primary human peripheral blood mononuclear cells were also demonstrated. Here, the anti-HIV-1 strategy utilizing gamma-GCE is removal of both HIV-1-producing cells and free infectious HIV-1 in vitro, in place of specific immunoclearance in vivo, which might lead to an arrest or slowing of viral propagation in HIV-1-infected individuals.
authors.affiliation: Center for Human Virology, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kubota
authors.forename: S
authors.initials: S
authors.lastname: Shetty
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Kitahara
authors.forename: R J
authors.initials: RJ
authors.lastname: Pomerantz
mesh_terms: D019380:Anti-HIV Agents / Q000737:chemistry / Q000494:pharmacology*; D000956:Antigens, Viral / Q000032:analysis; D002452:Cell Count / Q000187:drug effects; D004151:Dipeptides / Q000737:chemistry / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D013601:T-Lymphocytes / Q000187:drug effects / Q000821:virology; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D019380:Anti-HIV Agents; D000956:Antigens, Viral; D004151:Dipeptides; C067744:N-gamma-glutamylcysteine ethyl ester