title: Intestinal lamina propria retaining CD4+CD25+ regulatory T cells is a suppressive site of intestinal inflammation.
abstract: It is well known that immune responses in the intestine remain in a state of controlled inflammation, suggesting that not only does active suppression by regulatory T (T(REG)) cells play an important role in the normal intestinal homeostasis, but also that its dysregulation of immune response leads to the development of inflammatory bowel disease. In this study, we demonstrate that murine CD4(+)CD25(+) T cells residing in the intestinal lamina propria (LP) constitutively express CTLA-4, glucocorticoid-induced TNFR, and Foxp3 and suppress proliferation of responder CD4(+) T cells in vitro. Furthermore, cotransfer of intestinal LP CD4(+)CD25(+) T cells prevents the development of chronic colitis induced by adoptive transfer of CD4(+)CD45RB(high) T cells into SCID mice. When lymphotoxin (LT)alpha-deficient intercrossed Rag2 double knockout mice (LTalpha(-/-) x Rag2(-/-)), which lack mesenteric lymph nodes and Peyer's patches, are transferred with CD4(+)CD45RB(high) T cells, they develop severe wasting disease and chronic colitis despite the delayed kinetics as compared with the control LTalpha(+/+) x Rag2(-/-) mice transferred with CD4(+)CD45RB(high) T cells. Of note, when a mixture of splenic CD4(+)CD25(+) T(REG) cells and CD4(+)CD45RB(high) T cells are transferred into LTalpha(-/-) x Rag2(-/-) recipients, CD4(+)CD25(+) T(REG) cells migrate into the colon and prevent the development of colitis in LTalpha(-/-) x Rag2(-/-) recipients as well as in the control LTalpha(+/+) x Rag2(-/-) recipients. These results suggest that the intestinal LP harboring CD4(+)CD25(+) T(REG) cells contributes to the intestinal immune suppression.
authors.affiliation: Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Makita
authors.forename: Takanori
authors.initials: T
authors.lastname: Kanai
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nemoto
authors.forename: Teruji
authors.initials: T
authors.lastname: Totsuka
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Okamoto
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kiyono
authors.forename: Mamoru
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D002465:Cell Movement; D004268:DNA-Binding Proteins / Q000502:physiology; D005260:Female; D015212:Inflammatory Bowel Diseases / Q000276:immunology / Q000517:prevention & control*; D007413:Intestinal Mucosa / Q000276:immunology*; D008233:Lymphotoxin-alpha / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D008233:Lymphotoxin-alpha; C499308:Rag2 protein, mouse