ICOS+ Foxp3+ TILs in gastric cancer are prognostic markers and effector regulatory T cells

Research Project

Project/Area Number	16K19892
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	General surgery
Research Institution	Osaka University
Principal Investigator	KATO Ryo 大阪大学, 医学部附属病院, 医員 (80745422)
Project Period (FY)	2016-04-01 – 2018-03-31
Project Status	Completed (Fiscal Year 2017)
Budget Amount *help	¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000) Fiscal Year 2017: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000) Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Keywords	胃癌 / ICOS / 活性化Treg / ピロリ菌 / pDC / 制御性T細胞 / バイオマーカー
Outline of Final Research Achievements	Tissue-infiltrating mononuclear cells extracted from fresh gastric cancer tissues were analyzed by flow cytometry. ICOS+ Foxp3+ CD4T cell(ICOS+ Treg) TILs was higher in the late stages, and patients with higher ICOS+ Treg showed shorter relapse-free survival in gastric cancer. Moreover, ICOS+ Treg had highly immunosuppressive function. In multicolor immunohistochemistry and flow cytometry, the expression of ICOS in Treg was closely related to Helicobacter pylori infection and plasmacytoid dendritic cells (pDCs). Our results indicated the potential of ICOS+ Treg as prognostic markers and that of direct and indirect immunotherapy targeting for ICOS, pDC or Helicobacter pylori.