Macrophage migration inhibitory factor deficiency enhances immune response to Nippostrongylus brasiliensis.

Abstract

Infections with helminth parasites are endemic in the developing world and are a target for intervention with new therapies. Macrophage migration inhibitory factor (MIF) is a cytokine with pleiotropic effects in inflammation and immune responses. We investigated the role of MIF in a naturally cleared model of helminth infection in rodents, Nippostrongylus brasiliensis. At day 7 post infection MIF-deficient (MIF−/−) mice had reduced parasite burden and mounted an enhanced type 2 immune response (Th2), including increased Gata3 expression and IL-13 production in the mesenteric lymph nodes (MLNs). Bone marrow reconstitution demonstrated that MIF produced from hematopoietic cells was crucial and Rag1−/− reconstitution provided direct evidence that MIF−/− CD4+ T cells were responsible for the augmented parasite clearance. MIF−/− CD4+ T cells produced less IL-6 post infection, which correlated with enhanced Th2 responses. MIF−/− CD4+ T cells exhibited lower NF-kB activation, potentially explaining the reduction in IL-6. Finally, we demonstrated enhanced clearance of the parasite and Th2 response in WT mice treated with the MIF tautomerase inhibitor, sulforaphane, a compound found naturally found in cruciferous vegetables, These results are the first to describe the importance of the tautomerase enzyme activity in MIF function in N. brasiliensis infection.