オカザキ　カズイチ   OKAZAKI KAZUICHI   岡崎　和一    所属   関西医科大学  附属香里病院    職種   病院長
言語種別	英語
発表タイトル	CROSS-PRIMED CD8+ CYTOTOXIC T CELLS INDUCE SEVERE HELICOBACTER-ASSOCIATED GASTRITIS IN THE ABSENCE OF CD4+ T CELLS.
会議名	7th China-Korea-Japan Joint Conference on Helicobacter Infection
学会区分	国際学会及び海外の学会
発表形式	ポスター掲示
講演区分	一般
発表者・共同発表者	◎Fukui T, Okazaki K, Nishio A, Chiba T
発表年月日	2008/02
開催地 （都市, 国名）	京都市
概要	Background: Although previous studies have reported important roles of CD4+ type1-helper T cells and regulatory T cells in Helicobacter-associated gastritis, the significance of CD8+ cytotoxic T cells remains unknown. To study the roles of CD8+ T cells, we examined the immune response in the gastric mucosa of Helicobacter felis-infected major histocompatibility complex (MHC) class II-deficient (II-/-) mice, which lack CD4+ T cells. Materials and Methods: Stomachs from Helicobacter felis-infected wild-type and infected MHC II-/- mice were examined histologically and immunohistochemically. Gastric acidity and serum levels of anti-Helicobacter felis antibodies were measured. The expression of pro-inflammatory and anti-inflammatory cytokine, Fas-ligand, perforin, and Foxp3 genes in the gastric mucosa was investigated. Results: Helicobacter felis-infected MHC II-/- mice developed severe gastritis, accompanied by marked infiltration of CD8+ cells. At 1 and 2 months after inoculation, mucosal inflammation and atrophy were more severe in MHC II-/- mice, although gastritis had reached similar advanced stages at 3 months after inoculation. There was little infiltration of CD4+ cells, and no Foxp3-positive cells were detected in the gastric mucosa of the infected MHC II-/- mice. The expression of the interleukin-1β and Fas-ligand genes was up regulated, but that of Foxp3 was down regulated in the infected MHC II-/- mice. Serum levels of anti-Helicobacter felis antibodies were lower in the infected MHC II-/- mice, despite severe gastritis. Conclusions: The present study suggests that cross-primed CD8+ cytotoxic T cells can induce severe Helicobacter-associated gastritis in the absence of CD4+ helper T cells and that Foxp3-positive cells may have an important role in the control of gastric inflammation.