S1656 CD4+CD25+ Regulatory T Cells Suppress Both TH1- and TH17-Reactions in An Experimental Colitis

G A A b st ra ct s was determined in amultiplex immunoassay. Results: Prdx6 protein expression was decreased by acute and chronic colitis in wildtype as well as in Prdx6 overexpressing animals. No differences in the development of acute colitis could be observed between wildtype and Prdx6 overexpressing animals but Prdx6 knockout animals displayed lower histological scores in acute as well as in chronic DSS colitis. Prdx6 overexpressing animals on the other hand showed a higher histological score in the proximal colon after induction of chronic DSS colitis. In the chronic colitis model increased secretion of proinflammatory (e.g. TNFα, IL-6) as well as antiinflammatory (e.g. IL-10, IL-2, IL-4, IL-5) cytokines by mesenterial lymph node cells could be observed in Prdx6 knockout animals in comparison to wildtype animals whereas lower levels of these cytokines were secreted by mesenterial lymph node cells isolated from Prdx6 overexpressing animals. Conclusion: Our data suggest that effective defense against bacterial translocation by reactive oxygen species might ameliorate the course of DSS-colitis as Prdx6 knockout animals, in which less neutralization of ROS occurs, displayed lower histological scores in acute as well as in chronic colitis