Identification of the Th17 cell-inducing bacteria from IBD patients

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H05657
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Immunology
• Research Institution: Keio University
• Principal Investigator: Atarashi Koji 慶應義塾大学, 医学部(信濃町), 准教授 (60546787)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: Th17細胞 / microbiota / IBD

Outline of Final Research Achievements

Th17 cells play a role in host defense against extracellular pathogens and also pathogenesis of multiple inflammatory and autoimmune disorders. I have identified the human gut bacteria that could induce intestinal Th17 cells. Th17 cells were significantly increased in the colon of the germ-free mice inoculated with fecal samples from Ulcerative colitis (UC) patients. This Th17 cell induction was further enhanced when the mice were treated with Ampicillin (Amp) in the drinking water. To isolate Th17-inducing bacterial species, I cultured cecal contents from these UC feces colonized and Amp treated mice. I isolated 20 bacterial strains belonging to Clostridium, Bifidobacterium, Ruminococcus, and Bacteroides and inoculated germ-free mice with these 20 strains. The colonization of these 20 strains strongly induced a robust accumulation of Th17 cells in the colon. Furthermore, nine out of the 20 strains were significantly increased in the microbiomes of UC and Crohn’s disease subjects.

Free Research Field

粘膜免疫学