Candidacidal Activity of Macrophages from Immunocompetent and Congenitally Immunodeficient Mice

Abstract

The chemotactic, phagocytic, and candidacidal activities of peritoneal exudate macrophages from immunocompetent heterozygous (bg/+) and immunodeficient homozygous (bg/bg, bg/bg-nu/+, and bg/bg-nu/nu) beige mice were assessed. Overall, macrophages from all strains of mice tested not only were able to migrate into the peritoneal cavity in response to several eliciting agents but showed a comparable capacity to phagocytize fluorescein isothiocyanate-labeled, heat-killed Candida albicans. However, some populations of peritoneal exudate macrophages from homozygous beige mice (e.g., thioglycollate-elicited) and resident peritoneal macrophages from bg/bg mice incubated in vitro with supernatants from concanavalin A-stimulated splenocytes had poorer candidacidal activity than did control macrophages from bg/+ mice. Interferon-γ enhanced the in vitro candidacidal activity of macrophages from homozygous and heterozygous beige mice. As indicated by inhibitors, poor macrophage candidacidal activity seemed to correlate better with deficient nitric oxide- than with superoxide anion-mediated killing. These data suggest that impaired candidacidal activity of macrophages from homozygous beige mice may explain their enhanced susceptibility to candidiasis.