Monocytes/macrophages from human immunodeficiency virus (HIV)-infected patients had a defect in their ability to kill Rhodococcus equi in vitro, as compared with healthy HIV-seronegative individuals. Virulent and avirulent R. equi strains isolated from humans and horses showed no significant intracellular replicative differences within both HIV-positive and -negative monocytes/macrophages. Infection with R. equi induced the production of nitric oxide (NO) by monocytes/macrophages from healthy individuals, but not by cells from HIV-positive patients. The NO formation was significantly inhibited by L-N-G-monomethyl arginine and arginase. However, neither competitive inhibition of NO synthesis from L-arginine with L-NMMA nor depletion of arginine with arginase altered the killing activity of human monocytes/macrophages against R. equi, thus suggesting that L-arginine:NO pathway is not required for the intracellular antirhodococcal mechanisms of human monocytes/macrophages. (C) 1998 Published by Elsevier Science B.V.
Rhodococcus equi infection of monocytes/macrophages from human immunodeficiency virus (HIV)-infected patients and healthy individuals: evaluation of intracellular killing and nitric oxide production / Vullo, Vincenzo; Mastroianni, Claudio Maria; Lichtner, Miriam; Fabio, Mengoni; Claudia, D'Agostino; Gabriele, Forcina; Angela, Corpolongo; Delia, Salvatore. - In: FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY. - ISSN 0928-8244. - 21:1(1998), pp. 11-17. [10.1111/j.1574-695x.1998.tb01144.x]
Rhodococcus equi infection of monocytes/macrophages from human immunodeficiency virus (HIV)-infected patients and healthy individuals: evaluation of intracellular killing and nitric oxide production
VULLO, Vincenzo;MASTROIANNI, Claudio Maria;LICHTNER, Miriam;DELIA, Salvatore
1998
Abstract
Monocytes/macrophages from human immunodeficiency virus (HIV)-infected patients had a defect in their ability to kill Rhodococcus equi in vitro, as compared with healthy HIV-seronegative individuals. Virulent and avirulent R. equi strains isolated from humans and horses showed no significant intracellular replicative differences within both HIV-positive and -negative monocytes/macrophages. Infection with R. equi induced the production of nitric oxide (NO) by monocytes/macrophages from healthy individuals, but not by cells from HIV-positive patients. The NO formation was significantly inhibited by L-N-G-monomethyl arginine and arginase. However, neither competitive inhibition of NO synthesis from L-arginine with L-NMMA nor depletion of arginine with arginase altered the killing activity of human monocytes/macrophages against R. equi, thus suggesting that L-arginine:NO pathway is not required for the intracellular antirhodococcal mechanisms of human monocytes/macrophages. (C) 1998 Published by Elsevier Science B.V.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.