Effects of porcine IL-17B and IL-17E against intestinal pathogenic microorganism

The interleukin-17 (IL-17) family plays a critical role in host defense, allergic reactions, and even tumorigenesis on different mucous membranes. IL-17 family has been cloned in human and mouse, as well IL-17A, IL-17 F in swine. So far, current knowledge on the cloning and biological functions of porcine IL-17B (poIL-17B) and porcine IL-17E (poIL-17E) is limited. In this study, poIL-17B and poIL-17E, mainly expressed in intestine, were cloned and characterized. Expression of poIL-17B and poIL-17E was upregulated after pathogenic microorganism infection. Moreover, the significant enhanced expression of antibacterial peptides PR-39 and pBD-1 was observed when poIL-17B and poIL-17E were over-expressed in the small intestinal epithelial cell line IPEC-J2. This demonstrated that poIL-17B and poIL-17E might have anti-infective capability. Pathogens infection data showed that pathogens could up-regulate poIL-17B/E expression levels. After stimulating the cells with the pathogen, continued with probiotics, the expression of poIL-17B/E was down-regulated. Meanwhile, the induced expression of poIL-17E was greater than that of poIL-17B. Invasion data indicated that poIL-17B and poIL-17E both could inhibit effectively pathogenic microorganism, while inhibitory capability of poIL-17B was stronger than that of poIL-17E. Therefore, poIL-17B and poIL-17E both could be important members against intestinal infection in the porcine IL-17 family. This study provided a theoretical basis for the prevention of intestinal diseases in pigs and thus achieved healthy farming.