Liposomes containing Candida albicans ribosomes as a prophylactic vaccine against disseminated candidiasis in mice

This study describes the development of prophylactic anti-Candida vaccine which combines the advantages of Candida albicans ribosomes as antigen(s) and of liposomes as carrier/adjuvant with minimal side-effects which could be suitable for human use. The liposomal vaccine was composed of C. albicans ribosomes and the lipids dimyristoyl phosphatidyl choline (DMPC) and dimyristoyl phosphatidyl glycerol (DMPG) (9:1 molar ratio). Some of the vaccines contained Lipid-A (LA) as an additional adjuvant. The vaccine was prepared by two methods. (I) dehydration by lyophylization of small liposomes in the presence of the Candida ribosomes (DRV method); (II) colyophylization of DMPC/DMPG (9:1 mole ratio) in tertiary butanol with aqueous dispersion of Candida ribosomes. In both cases a dry powder was obtained which was rehydrated to form large multilamellar vesicles. The efficacy of the vaccines in mice was tested by their protectivity against a challenge with C. albicans, as assessed by survival rate induction of cell mediated immunity (measured by delayed type hypersensitivity-DTH) and anti-Candida antibody titer. Unimmunized mice and mice vaccinated by ribosomes supplemented with incomplete Freund's adjuvant (IFA) were used as controls. The results indicated that the liposomal vaccines were effective at least as the IFA-based vaccine. The study indicates the feasibility of developing an efficacious anti-Candida vaccine for human use.