INTERACTION BETWEEN CRYPTOCOCCUS-NEOFORMANS AND ALVEOLAR MACROPHAGES

Citation
Nt. Gross et al., INTERACTION BETWEEN CRYPTOCOCCUS-NEOFORMANS AND ALVEOLAR MACROPHAGES, Journal of medical and veterinary mycology, 35(4), 1997, pp. 263-269
Citations number
29
Categorie Soggetti
Mycology
ISSN journal
02681218
Volume
35
Issue
4
Year of publication
1997
Pages
263 - 269
Database
ISI
SICI code
0268-1218(1997)35:4<263:IBCAAM>2.0.ZU;2-4
Abstract
Phagocytosis, oxidative metabolism and phagolysosomal pH of rat alveol ar macro-phages (AM) were studied at different points of time after ch allenge with Cryptococcus neoformans. Phagocytosis was evaluated using a fluorescent quenching technique which distinguishes between attache d and ingested organisms. The nitroblue tetrazolium (NET) test was use d as an indirect measurement of the oxidative metabolism of the phagoc ytes. The pH of the phagolysosomes was measured using a cytofluorometr ic technique. Both the attachment and ingestion of serum opsonized C. neoformans by AM were slow during the first hours of incubation, but w ere considerable after 24 h. The oxidative metabolism of AM challenged with the yeast was insignificant during the first hour, but reached h igh levels after 24 h. Most phagolysosomes in AM with ingested cryptoc occi had a pH < 5.5. Our results indicate that these AM defence mechan isms, although poor during the first hours after exposure to the yeast , are of significance after 24 h. Thus, in the immunocompetent host th e AM should prevent the dissemination of C. neoformans from the lungs.