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Differing requirement for inducible nitric oxide synthase activity in clearance of primary and secondary Cryptococcus neoformans infection
- Source :
- Medical Mycology; January 2000, Vol. 38 Issue: 5 p343-343, 1p
- Publication Year :
- 2000
-
Abstract
- The role of nitric oxide in resistance to cryptococcal infection was investigated. Mice deficient in inducible nitric oxide synthase (INOS) did not survive a primary intratracheal infection as did INOS-replete control mice. Despite adequate recruitment of host cells and generation of interferon (IFN)-? and tumor necrosis factor (TNF)-\ga at the site of infection, INOS-deficient mice failed to clear yeast from their lungs by five weeks of infection, in contrast to wild-type mice. INOS-deficient mice also had higher yeast brain burdens than did control mice after a primary intracerebral infection. Therefore, generation of nitric oxide is required for resistance to primary cryptococcal infection. However, INOS-deficient mice vaccinated subcutaneously and rechallenged intravenously had lung and brain yeast burdens equivalent to those of vaccinated controls, and therefore expressed effective acquired immunity to Cryptococcus neoformans</it>. Cells harvested from infected INOS-deficient mice by bronchoalveolar lavage acted as anti-cryptococcal effectors in vitro</it> at an effector:target ratio of 100:1, provided IFN-g was present, but did not inhibit yeast proliferation at a 10:1 effector:target ratio as cells from wild-type mice did. Therefore, INOS activity is important for anti-cryptococcal function of effectors of immunity during the primary response, but not for the generation or expression of secondary immunity to C. neoformans</it>.
Details
- Language :
- English
- ISSN :
- 13693786 and 14602709
- Volume :
- 38
- Issue :
- 5
- Database :
- Supplemental Index
- Journal :
- Medical Mycology
- Publication Type :
- Periodical
- Accession number :
- ejs31869468
- Full Text :
- https://doi.org/10.1080/mmy.38.5.343.353