Antiarthritic effect of VIP in relation to the host resistance against Candida albicans infection

Vasoactive intestinal peptide (VIP) is one of the prospective candidates for clinical application in rheumatoid arthritis (RA). Its antiarthritic effect is associated with the suppression of inflammatory and autoimmune responses. The ability of VIP to trigger a shift towards Th2 immunity suggests that anti-infectious host resistance might be affected. In the present study VIP was applied at the initiation and at the established phase of collagen-induced arthritis (CIA). Mice developed Th2 dominant anti-collagen response. The susceptibility to primary and secondary Candida albicans infection was determined after VIP administration at the established CIA. The percentage of survivors, kidney colonization, cytokine secretion by splenocytes and specific antibody synthesis were assessed. Reduced TNF-alpha production but not IFN-gamma and IL-10 was observed after the first challenge with the pathogen in CIA mice treated with VIP while the percentage of survivors was not significantly changed. The adaptive immune response was impaired in VIP-treated mice as they were more susceptible to reinfection, showed increased kidney colonization and suppressed anti-Candida IgG antibody production.