INTERLEUKIN-2 ACTIVITY OF COLONIC LAMINA PROPRIA MONONUCLEAR-CELLS IN A RAT MODEL OF EXPERIMENTAL COLITIS

Background: Altered interleukin 2 (IL-2) production has been implicated in the pathogenesis of inflammatory bowel diseases. Methods: The temporal relationship between IL-2, prostaglandin E2 (PGE2) production, and mucosal injury was evaluated by isolated colonic lamina 3 propria mononuclear cells (LPMC), using the trinitrobenzene sulfonic acid model of rat colitis. Results: Spontaneous LPMC IL-2 activity was significantly increased in chronic (5 weeks) but not acute (5 days) or resolved colitis groups. IL-2 activity after concanavalin A activation was highest in the groups with resolved and chronic colitis. PGE2 production was significantly increased in LPMC cultures in acute or chronic colitis as well as the ethanol control groups but not the resolved colitis group. The addition of indomethacin to LPMC cultures decreased PGE2 levels in all groups, whereas IL-2 activity increased only for the chronic and resolved colitis groups. No correlation was found between PGE2 and IL-2 production by LPMC. Conclusions: In this experimental model, LPMC IL-2 production varied according to the severity and duration of the inflammation. Increased PGE2 production does not appear to be responsible for the IL-2 alterations in colitis. © 1993.