Lay Summary

Proposal No.  IBD-0160
Principal Investigator:  Atsushi Mizoguchi, M.D., Ph.D.
Applicant Organization:  Massachusetts General Hospital (Boston, U.S.A.)
Project Title:  Therapeutic approach using interleukin-22 in experimental colitis
Period of Award:  November 1, 2005 – April 30, 2008

Inflammatory bowel disease (IBD) is a group of chronic, relapsing intestinal inflammatory conditions that affect individuals throughout their life.  Undesired responses of host to intestinal bacteria play an important role in the development, exacerbation and perpetuation of IBD.  To prevent the development of the undesired host responses, epithelial cells and specific immune cells (termed as innate cells) have been considered to be the key players.  Because the epithelial cells anatomically make a barrier between intestinal bacteria and host and in case intestinal bacteria invade into the host, the innate cells can remove the invading bacteria from the host by bacterial uptake.  Therefore, we predict that activation of these cells contributes to the suppression of IBD.  Several factors have been identified to induce the activation of these regulatory cells.  However, one of the concerns is that these previously identified factors influence many cell populations, including helpful and detrimental cells.  A new factor, termed as interleukin-22, which may be protective, has been identified recently.  This factor may activate regulatory cells (epithelial cells and innate cells) without influencing other cell populations.  Therefore, we will study interleukin-22 as a new and potentially more effective therapeutic strategy to improve the lives of patients with IBD.