Immunodeficient CBA/N mice respond effectively to Candida albicans

Abstract

An immune defect in CBA/N mice diminishes their ability to respond adequately to certain well-defined antigens. Since the contribution of T and B cells to immunity in candidiasis has not been clearly defined, it was hoped that CBA/N mice might prove a useful model for the study of specific responses to Candida albicans. Therefore, immunodeficient CBA/N and immunocompetent CBA/J mice were immunized by two cutaneous inoculations of viable C. albicans B311 given 2 weeks apart and challenged iv 14 days after the second inoculation. Delayed-type hypersensitivity (DTH) was tested with a membrane-derived antigen (B-HEX) 7 days following the second inoculation, and lymphocyte stimulation with B-HEX, a cytoplasmic antigen (SCS), and mitogens was done at 12 days. Antibody to SCS was determined by ELISA 2 days after DTH testing and 28 days after iv challenge, at which time the animals were sacrificed for quantitative culture of kidneys and brains. Naive CBA/N mice were no more susceptible to challenge than CBA/J mice in that the mean log colony-forming units (CFU) were 3.79 and 5.48, respectively. Both strains responded to immunization by a similar reduction in CFU, a marked DTH response (e.g., reactions at 24 hr were 1.12 mm for CBA/N and 1.34 mm for CBA/J), and significant and similar quantities of antibody. The immune defect in CBA/N mice had no demonstrable effect on the development of immune responses to infection with C. albicans.