Follicular helper T cells recruit eosinophils into host liver by producing CXCL12 during Schistosoma japonicum infection.

Schistosomiasis affects at least 200 million people in tropical and subtropical areas. The major pathology of schistosomiasis is egg-induced liver granuloma characterized by an eosinophil-rich inflammatory infiltration around the eggs, which subsequently leads to hepatic fibrosis and circulatory impairment in host. However, the mechanisms how eosinophils are recruited into the liver, which are crucial for the better understanding of the mechanisms underlying granuloma formation and control of schistosomiasis, remain unclear. In this study, we showed that follicular helper T (Tfh) cells participate in recruitment of eosinophils into liver partially by producing CXCL12 during schistosome infection. Our findings uncovered a previously unappreciated role of Tfh cells in promotion of the development of liver granuloma in schistosomiasis, making Tfh-CXCL12-eosinophil axis a potential target for intervention of schistosomiasis.