Linoleic acid stimulation results in TGF-ß1 production and inhibition of PEDV infection in vitro.

ABSTRACT

Linoleic acid (LA) is recommended to improve pork quality. However, whether it affects the intestinal immune response in pigs is still unclear. Our ex vivo experiments demonstrated that LA stimulation resulted in increased frequencies of Tregs in PBMCs but not in Peyer's Patches (PPs). The results of RT-qPCR, flow cytometry, and ELISA indicated that LA increased the TGF-ß1 expression level in DCs isolated from PEDV infected pigs. Furthermore, RT-qPCR and flow cytometry results demonstrated that TGF-ß1 was associated with higher frequencies of Tregs both in PBMCs and PPs. Additional investigations showed that TGF-ß1 inhibited PEDV infection in vitro. Besides, knocking-out TGF-ß1 in IPEC-J2 cells resulted in higher viral load. Taken together, our results demonstrated that LA stimulation resulted in enhanced production of TGF-ß1 by DC, which resulted in higher frequencies of Tregs production and inhibition of PEDV infection.