Clinical Research
Copyright ©2007 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 7, 2007; 13(45): 5995-6002
Published online Dec 7, 2007. doi: 10.3748/wjg.v13.i45.5995
Selective decrease in colonic CD56+ T and CD161+ T cells in the inflamed mucosa of patients with ulcerative colitis
Masaru Shimamoto, Yoshitaka Ueno, Shinji Tanaka, Toshiko Onitake, Rie Hanaoka, Kyoko Yoshioka, Tsuyoshi Hatakeyama, Kazuaki Chayama
Masaru Shimamoto, Toshiko Onitake, Rie Hanaoka, Kyoko Yoshioka, Tsuyoshi Hatakeyama, Kazuaki Chayama, Department of Medicine and Molecular Science, Hiroshima University, Hiroshima 734-8551, Japan
Yoshitaka Ueno, Shinji Tanaka, Department of Endoscopy, Hiroshima University Hospital, Hiroshima Japan
Author contributions: All authors contributed equally to the work.
Correspondence to: Yoshitaka Ueno, MD, PhD, Department of Endoscopy, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551,Japan. yueno@hiroshima-u.ac.jp
Telephone: +81-82-2575193 Fax: +81-82-2575194
Received: May 10, 2007
Revised: August 10, 2007
Accepted: October 5, 2007
Published online: December 7, 2007
Abstract

AIM: To investigate the role of local colonic mucosal NK receptor-positive T (NKR+ T) cells in the regulation of intestinal inflammation, we analyzed the population and function of these cells in ulcerative colitis (UC).

METHODS: Colonic mucosal tissues were obtained from colonoscopic biopsies of the descending colon from 96 patients with UC (51 endoscopically uninflamed, 45 inflamed) and 18 normal controls. Endoscopic appearance and histologic score at the biopsied site were determined by Matts’ classification. A single cell suspension was prepared from each biopsy by collagenase digestion. Two NKR+ T cell subsets, CD56+ (CD56+CD3+) T cells and CD161+ (CD161+CD3+) T cells, were detected by flow cytometric analysis. Intracellular cytokine analysis for anti-inflammatory cytokine interleukin-10 (IL-10) was performed by in vitro stimulation with phorbol-myristate-acetate (PMA) and ionomycin.

RESULTS: CD56+ T cells and CD161+ T cells are present in the normal human colon and account for 6.7% and 21.3% of all mononuclear cells, respectively. The populations of both CD56+ T cells and CD161+ T cells were decreased significantly in the inflamed mucosa of UC. In contrast, the frequency of conventional T cells (CD56-CD3+ cells and CD161-CD3+ cells) was similar among the patient and control groups. The populations of NKR+ T cells were correlated inversely with the severity of inflammation, which was classified according to the endoscopic and histologic Matts’ criteria. Interestingly, approximately 4% of mucosal NKR+ T cells expressing IL-10 were detected by in vitro stimulation with PMA and ionomycin.

CONCLUSION: Selective reduction in the population of colonic mucosal NKR+T cells may contribute to the development of intestinal inflammation in UC.

Keywords: Natural killer T cells, Ulcerative colitis, Interleukin-10