Anti-enolase antibodies partially protective against systemic candidiasis in mice

OBJECTIVE: The evaluation of the effect of protective capacities of antibodies directed against the immunodominant enolase antigen of C. albicans on the survival rate of mice with systemic candidiasis. METHODS: Passive transfer of heterologous rabbit antibodies (IRS) directed against a crude Candida albicans extract and homologous mice anti-enolase antibodies (IMS) in a non-acute but lethal systemic Candida model in mice. RESULTS: Protection could only be demonstrated by repeated administration of homologous as well as heterologous immune sera. The protective effect was not due to non-specific, heat-labile, serum factors, since fractionated anti-cytoplasmic rabbit immunoglobulins also gave a decreased mortality rate. These findings could not be ascribed to enhanced opsonization as observed in in vitro opsonization experiments using peritoneal macrophage monolayers. CONCLUSIONS: Anti-enolase antibodies are partially protective against lethal C. albicans infections. The protection was not due to enhanced initial clearance of viable C. albicans from the internal organs, but was presumably the result of as yet unknown effects of antibodies occurring later in the infectious process.