DIRECT SECRETORY EFFECT OF INTERLEUKIN-1 VIA TYPE-I RECEPTORS IN HUMAN COLONIC MUCOUS EPITHELIAL-CELLS (HT29-CL.16E)

The stable differentiated human colonic epithelial cell line, HT29-Cl. 16E, was used to study the effects of interleukin-1 (IL-1) on mucin ex ocytosis. The main findings include: (a) IL-1 stimulated a rapid relea se of mucin from filter grown HT29-Cl.16E cells, this effect being dos e related; (b) this secretory effect was abolished in the presence of the blocking monoclonal antibody M4 specific for IL-1 receptors type I , showing that IL-1 receptors type I mediated IL-1 action; (c) experim ents based on chamber cultures showed that these receptors were locate d on the basolateral membranes of HT29-Cl.16E cells; (d) finally, mRNA for IL-1 receptors type I were detected by reverse transcriptase-poly merase chain reaction in these cells. To extend these findings to the in vivo situation, the rapid stimulatory effect of IL-1 on mucin exocy tosis may contribute to the wash out of noxious agents during mucosal inflammation.