title: Evidence for the participation of proteinases released by Candida albicans in the early killing of peritoneal macrophages in vitro.
abstract: 1. We have investigated the possibility that proteinases released by Candida albicans participate in the early killing of three types of mice peritoneal macrophage (resident, thioglycollate-elicited, or Con A-activated) in vitro. 2. Phagocytic assays were performed by incubation of macrophages and C. albicans together at a 1:10 ratio for 30 min at 37 degrees C in RPMI medium buffered to pH 7.0 with 12 mM Hepes without serum. With no albumin added to the medium, the macrophages were 85% to 100% damaged and unviable, to a greater extent than expected from the proportion of phagocytic cells containing germ tubes. When 10 mg/ml of albumin was added to the medium, however, 90% of the macrophages remained viable for the 2 hours of the phagocytic assay, suggesting that albumin may have acted as a substrate for or inhibitor of proteinases released by C. albicans, thereby protecting the macrophage from the proteolytic action of the proteinases. 3. The phagocytosis of IgG-coated erythrocytes was reduced to 43% when IgG was preincubated with the supernatant from C. albicans cultures, but the addition of 10 mg/ml albumin or of 5 micrograms/ml pepstatin (an inhibitor of C. albicans acid proteinases) to the same supernatants prevented the effect on phagocytosis of IgG-coated erythrocytes. 4. These results suggest that proteinases released from C. albicans are involved in the early killing of macrophages.
authors.affiliation: Departamento de Patologia Geral, Universidade Estadual de Londrina, Brasil.
authors.forename: G M
authors.initials: GM
authors.lastname: de-Andrade
authors.forename: I
authors.initials: I
authors.lastname: Felipe
mesh_terms: D000418:Albumins / Q000494:pharmacology; D000818:Animals; D002176:Candida albicans / Q000378:metabolism*; D002470:Cell Survival; D010450:Endopeptidases / Q000378:metabolism*; D006531:HEPES; D066298:In Vitro Techniques; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D010436:Pepstatins / Q000494:pharmacology; D010587:Phagocytosis
chemical_list: D000418:Albumins; D010436:Pepstatins; D010450:Endopeptidases; D006531:HEPES