title: Attachment of Blastomyces dermatitidis conidia to murine bronchoalveolar macrophages: characterization of binding and elicitation of respiratory burst.
abstract: We studied the mechanisms of adherence of Blastomyces dermatitidis conidia to murine bronchoalveolar macrophages and the ability of the conidia to elicit an increase in macrophage O2- production, using an avirulent fungal strain. The number of cell associated conidia was counted by visual inspection of 2 hour macrophage monolayers incubated with conidia and O2- was measured by reduction of ferricytochrome c. Adherence of conidia to bronchoalveolar macrophages was time dependent and reached a plateau after 30 min (36 +/- 5%, 51 +/- 22%, and 36 +/- 17% macrophages with adherent conidia after 15, 30, and 60 min, respectively). Both Ca+2 and Mg+2 were required. The carbohydrates mannose, mannan, fucose, alphamethylmannoside, beta-glucan, galactose, N-acetylglucosamine and chitotriose (100-1000 micrograms/ml) did not inhibit adherence of conidia to macrophages. Trypsin treatment of macrophages or conidia did not affect binding. Conidia did not stimulate bronchoalveolar macrophage production of O2- above baseline concentrations (2.0 +/- 0.9 vs 0.8 +/- 0.5 nmol O2-, p greater than 0.05). We conclude that murine bronchoalveolar macrophage--B. dermatitidis conidia interactions occur primarily by a non-lectin-like attachment and do not result in the production of macrophage derived O2-.
authors.affiliation: Evans Memorial Department of Clinical Research, Boston University Medical Center, MA 02118.
authors.forename: A M
authors.initials: AM
authors.lastname: Sugar
authors.forename: M
authors.initials: M
authors.lastname: Picard
mesh_terms: D000818:Animals; D001758:Blastomyces / Q000378:metabolism*; D001980:Bronchi / Q000166:cytology; D002118:Calcium / Q000494:pharmacology; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism* / Q000382:microbiology; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011650:Pulmonary Alveoli / Q000166:cytology; D013481:Superoxides / Q000378:metabolism*; D014357:Trypsin / Q000378:metabolism
chemical_list: D013481:Superoxides; D014357:Trypsin; D008274:Magnesium; D002118:Calcium