title: Molecular mechanism of T-cell control of Chlamydia in mice: role of nitric oxide in vivo.
abstract: T-cell-mediated immunity is crucial for the control of Chlamydia in mice. Recent evidence from studies in an in vitro model of the mucosal epithelium, the polarized epithelial-lymphocyte co-culture (PELC) system, indicated that protective murine T cells mediated intracellular inhibition of the Chlamydia trachomatis agent of mouse pneumonitis (MoPn) at least partly by activating the interferon-gamma (IFN-gamma)-inducible nitric oxide synthase (iNOS) pathway. To investigate whether nitric oxide played a role in controlling chlamydial infection in vivo, the protective capacity of a chlamydial-specific T-cell clone (clone 2.14-0) was analysed in mice in the presence of a specific inhibitor of iNOS. The results revealed that the ability of this clone to clear Chlamydia in vivo is in part mediated by induction of nitric oxide (NO) production. The L-arginine analogue and iNOS inhibitor, NG-monomethyl-L-arginine monoacetate (MLA), increased the chlamydial burden in infected mice and inhibited the ability of clone 2.14-0 to clear genital MoPn infection in vivo. The results are consistent with the working hypothesis that the IFN-gamma-inducible iNOS pathway is involved in the control of Chlamydia by T lymphocytes in mice.
authors.affiliation: Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock 72205, USA.
authors.forename: J U
authors.initials: JU
authors.lastname: Igietseme
mesh_terms: D000818:Animals; D001120:Arginine / Q000819:agonists / Q000031:analogs & derivatives / Q000494:pharmacology; D002690:Chlamydia Infections / Q000276:immunology*; D002692:Chlamydia trachomatis; D002999:Clone Cells; D007111:Immunity, Cellular; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000502:physiology* / Q000652:urine; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000502:physiology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D019323:omega-N-Methylarginine
chemical_list: D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase