Nitric oxide mediates murine cytomegalovirus-associated pneumonitis in lungs that are free of the virus.
4 wk after intraperitoneal inoculation of 0.2 LD50 (50% lethal dose) of murine cytomegalovirus (MCMV) in adult BALB/c mice, MCMV remained detectable in the salivary glands, but not in the lungs or other organs. When the T cells of these mice were activated in vivo by a single injection of anti-CD3 monoclonal antibody, interstitial pneumonitis was induced in the lungs that were free of the virus with an excessive production of the cytokines. In the lungs of such mice persistently infected with MCMV, the mRNA of the cytokines such as IL-2, IL-6, TNF-alpha, and IFN-gamma were abundantly expressed 3 h after the anti-CD3 injection, and the elevated levels continued thereafter. A marked expression of inducible nitric oxide synthetase (iNOS) was then noted in the lungs, suggesting that such cytokines as TNF-alpha and IFN-gamma may have induced iNOS. Although the increase in NO formation was demonstrated by the significant elevation of the serum levels of nitrite and nitrate, the interstitial pneumonitis was not associated with either increased superoxide formation or peroxynitrite-induced tyrosine nitration. Nevertheless, the administration of an NO antagonist also alleviated the interstitial pneumonitis provoked by anti-CD3 mAb. Based on these findings, it was concluded that MCMV-associated pneumonitis is mediated by a molecule of cytokine-induced NO other than peroxynitrite.
Tanaka
K
K
Department of Infectious Diseases, Tokai University School of Medicine, Bohseidai, Isehara, Kanagawa 259-11, Japan. tanakaka@is.icc.u-tokai.ac.jp
Nakazawa
H
H
Okada
K
K
Umezawa
K
K
Fukuyama
N
N
Koga
Y
Y
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001992:Bronchoalveolar Lavage Fluid; D017252:CD3 Complex / Q000276:immunology; D003497:Cyclic N-Oxides; D016207:Cytokines / Q000096:biosynthesis; D003586:Cytomegalovirus Infections / Q000150:complications* / Q000276:immunology / Q000473:pathology; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D017563:Lung Diseases, Interstitial / Q000139:chemically induced / Q000209:etiology* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018146:Muromegalovirus; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis; D009573:Nitrites / Q000097:blood; D009589:Nitrogen Oxides / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D017382:Reactive Oxygen Species; D014443:Tyrosine / Q000032:analysis; D014968:Xanthine Dehydrogenase / Q000032:analysis; D014969:Xanthine Oxidase / Q000032:analysis
D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D003497:Cyclic N-Oxides; D016207:Cytokines; D009566:Nitrates; D009573:Nitrites; D009589:Nitrogen Oxides; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; C029217:phenyl-N-tert-butylnitrone; D014443:Tyrosine; D019001:Nitric Oxide Synthase; D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase; D019331:NG-Nitroarginine Methyl Ester