PEDV promotes the differentiation of CD4 + T cells towards Th1, Tfh, and Treg cells via CD103 + DCs.

Porcine epidemic diarrhea virus (PEDV) can infect all ages of pigs, particularly newborn piglets with a mortality almost reaching to 80-100%, causing significant economic losses to the global pig industry. The mucosal immune response is crucial for PEDV prevention, in which specific dendritic cells (DCs) and differentiated T cells play vital roles. In this study, CD103DCs were differentiated successfully with retinoic acid (RA) treatment in vitro. PEDV could not replicate efficiently in differentiated CD103DCs but could promote maturation of CD103DCs by up-regulating the expression of SLA-DR, CD1a, CD86, and cytokines of IL-1β and IL-10. In addition, PEDV-infected CD103DCs and CD4T cells were co-cultured, and the results showed that the differentiation of CD4T cells toward Th1, Tfh, and Treg, but not Th2. These results demonstrate that PEDV-infected CD103DCs could promote the differentiation of CD4T cells, which provided the basis for further study of mucosal response induced by PEDV via CD103DCs.