Oral administration of inactivated porcine epidemic diarrhea virus activate DCs in porcine Peyer’s patches

Yuan, Chen; Zhang, En; Huang, Lulu; Wang, Jialu; Yang, Qian

PPs is the main site of induction of IgA-producing plasma B cells by DCs loaded with commensal bacteria [29] . Inactivated viruses are usually not sufficiently effective in eliciting local mucosal immune response. DCs play a significant role in the application of inactivated PEDV oral vaccine. After oral administration of antigens, PPs are the first places of T-cell-specific priming and proliferation in the gut. DCs promote lymphocytes proliferation and secreting cytokines against an array of invading pathogens including PEDV. DCs derived from spleen (SP) exhibit strong functional differences as compared to DCs derived from PPs [30] . DCs from PPs are more potent in stimulating allogeneic T-cells proliferation compared with DCs from SP. As well as, the DCs derived from PPs are able to prime the production of IL-4 and IL-10 (Th2 anti-inflammatory cytokines), while DCs from SP lack this ability [30] . Therefore, designing vaccines targeting DCs may be potential agents for the suppression of viral infections. In this study, our results indicated that DCs in porcine PPs after oral administration of inactivated PEDV not only can stimulate the proliferation of allogeneic lymphocytes, but also can stimulate lymphocytes to secrete cytokines (IL-1 and IL-4), after the mixed reaction of DCs and allogeneic lymphocytes. In addition, we also found that the number of ileum IgA + cells and DCs in porcine ileum significantly increased in piglets in vitro and the levels of anti-PEDV specific IgG antibody in the serum and SIgA antibody in the feces increases after oral administration of inactivated PEDV.