Dual-antigen fusion protein vaccination induces protective immunity againstinfection in mice.

Abstract

Is a leading cause of nosocomial bloodstream infections, particularly in immunocompromised patients. Current therapeutic strategies are insufficient, highlighting the need for effective vaccines. This study aimed to evaluate the efficacy of a dual-antigen fusion protein vaccine (AH) targeting the Als3 and Hyr1 proteins of, using AlPOas an adjuvant. The AH vaccine was constructed by fusing Als3and Hyr1proteins, and its immunogenicity was tested in BALB/c mice and New Zealand white rabbits. Mice received three intramuscular doses of the vaccine combined with AlPO, followed by a lethal challenge withSC5314. Survival rates, antibody responses, cytokine production, fungal burdens, and organ pathology were assessed. The vaccine's efficacy was also validated using rabbit serum. Mice vaccinated with the AH-AlPOcombination exhibited significantly higher antibody titers, particularly IgG and its subclasses, compared to controls (&#x2009;<&#x2009;.001). The survival rate of vaccinated mice was 80% post-infection, significantly higher than the control group (&#x2009;<&#x2009;.01). Vaccinated mice showed reduced fungal loads in the blood, kidneys, spleen, and liver (&#x2009;<&#x2009;.05). Increased levels of interferon gamma and interleukin (IL)-17A were observed, indicating robust T helper (Th) 1 and Th17 cell responses. Vaccination mitigated organ damage, with kidney and liver pathology scores significantly lower than those of unvaccinated mice (&#x2009;<&#x2009;.05). Rabbit serum with polyclonal antibodies demonstrated effective antifungal activity, confirming vaccine efficacy across species. The AH-AlPOvaccine effectively induced strong immune responses, reduced fungal burden, and protected against organ pathology ininfections. These findings support further development of dual-antigen vaccine strategies.