Tolerogenic Vaccination with MOG /VitD Overcomes Aggravating Effect of C. albicans in Experimental Encephalomyelitis

Summary Aims Multiple sclerosis ( MS ) is an immune‐mediated demyelinating disorder of the central nervous system ( CNS ). We described that Candida albicans (Ca) aggravates experimental autoimmune encephalomyelitis ( EAE ) that is a model to study MS . We also observed that vaccination with a myelin peptide ( MOG ) in the presence of vitamin D (VitD) protected mice against EAE . In this work, we investigated whether Ca infection interferes with the efficacy of this vaccine. Methods EAE was induced in C57 BL /6 female mice previously vaccinated with MOG +VitD and then infected 3 days before encephalomyelitis induction. Results Vaccination was able to control EAE development in infected mice. These animals gained weight, and only a few progressed to very low clinical scores. Protection was confirmed by a lower inflammatory infiltration in the CNS and was also associated with a reduced production of encephalitogenic cytokines by spleen and CNS cell cultures. The elevated percentage of CD 25 + FoxP3 + cells suggests that regulatory T cells are involved in the protection. Adoptive transfer of splenocytes from mice vaccinated with MOG +VitD supports the view that protection is mediated by immunoregulatory cells. Conclusion Together, these experiments provide evidence demonstrating that EAE can be prevented by the inverse vaccination with MOG +VitD even in the presence of a disease‐aggravating infectious agent.