Candida albicans mannan-protein conjugate as vaccine candidate.

Mannan-branched polysaccharide with alpha-(1-->6)-linked mannose residues in the linear backbone, is a major virulence and protective factor of yeast Candida albicans. Injected alone does not induce sufficient level of protective antibodies. In this study, we have conjugated mannan to protein carrier by simple one step reaction using 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) activation reagent. Prepared mannan conjugate is immunogenic in rabbits and reinjection elicited a booster response with significant increase of serum IgG level. Anti-C. albicans effectiveness of immune serum is clearly demonstrated. Based on these results, the mannan conjugate synthesized by this scheme can be considered as actual vaccine candidate for clinical evaluation.