부산대학교 도서관

Staphylococcus aureusis an opportunistic pathogen historically considered a minor contributor to porcine illness, but recent work has pointed to the potential of pigs as a source of zoonotic methicillin-resistant S. aureus(MRSA) infections. S. aureusis adept at acquiring antibiotic-resistance genes and has become a pathogen of interest due to its implications in pig and human health. The innate immune response plays a critical role in controlling gram positive bacterial infections (such as S. aureus) in the intestine. To elucidate the acute immune response to gram positive infections, we challenged a porcine intestinal cell line (IPEC-J2) with gram-positive antigens isolated from S. aureus. IPEC-J2 cells were grown in collagen-coated transwell dishes until a transepithelial electrical resistance (TEER) reading of >1 kΩcm2was obtained. Cells were then challenged with 100ug/ul peptidoglycan (PGN) or 10ug/ul lipoteichoic acid (LTA) for 3, 8 or 24 hours prior to cell and supernatant collection. Butyrate is a short chain fatty acid in the gut that has known protective effects on barrier function and intestinal health. To test the protective effect of butyrate on gram-positive intestinal infections, IPEC-J2 cells were pre-treated with butyrate for 24 hours prior to PGN or LTA challenge. Pre-treatment with butyrate prior to PGN or LTA challenge resulted in statistically significant increases of IL-1RA. After antigen challenge alone, levels of IL-1RA and IL-8 did not increase significantly over time in the cellular supernatant. IL-1b, IL-4, IL-2, IL-6, IL-10, IL-12, and IL-18 were not significantly altered by antigen challenge +/- butyrate pre-treatment. These data indicate an acute inflammatory response is produced by IPEC-J2 cells upon exposure to antigens from gram-positive bacteria, but pre-treatment with butyrate promotes an anti-inflammatory response, that may reduce intestinal damage, through increased IL-1RA secretion.