title: Decreased Frequency of Intestinal Regulatory CD5+ B Cells in Colonic Inflammation.
abstract: BACKGROUND
  CD5+ B cells are a type of regulatory immune cells, though the involvement of this B cell subset in intestinal inflammation and immune regulation is not fully understood.
  
  
  METHODS
  We examined the distribution of CD5+ B cells in various mouse organs. Expression levels of CD11b, IgM, and toll-like receptor (TLR)-4 and -9 in B cells were evaluated. In vitro, TLR-stimulated IL-10 production by colonic lamina propria (LP) CD5+ and CD5- B cells was measured. In vivo, mice with acute or chronic dextran sulfate sodium (DSS)-induced colonic injury were examined, and the frequency of colonic LP CD5+ B cells in those was assessed by flow cytometry.
  
  
  RESULTS
  The expression level of TLR9 was higher in colonic LP CD5+ B cells as compared to CD5- B cells. Colonic LP CD5+ B cells produced greater amounts of IL-10 following stimulation with TLR ligands, especially TLR9, as compared with the LP CD5- B cells. Acute intestinal inflammation transiently decreased the frequency of colonic LP CD5+ B cells, while chronic inflammation induced a persistent decrease in colonic LP CD5+ B cells and led to a CD5- B cell-dominant condition.
  
  
  CONCLUSIONS
  A persistent altered mucosal B cell population caused by chronic gut inflammation may be involved in the pathogenesis of inflammatory bowel diseases.
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Mishima
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Ishihara
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Oka
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Fukuba
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Oshima
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sonoyama
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Noritsugu
authors.initials: N
authors.lastname: Yamashita
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Tada
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Ryusaku
authors.initials: R
authors.lastname: Kusunoki
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.|Cancer Center, Shimane University Hospital, Izumo, Shimane, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Moriyama
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yuki
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Kousaku
authors.initials: K
authors.lastname: Kawashima
authors.affiliation: Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kinoshita
mesh_terms: D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D039481:CD11b Antigen / Q000032:analysis; D018956:CD5 Antigens / Q000032:analysis; D002908:Chronic Disease; D003092:Colitis / Q000139:chemically induced / Q000276:immunology*; D016264:Dextran Sulfate / Q000633:toxicity; D007075:Immunoglobulin M / Q000032:analysis; D016753:Interleukin-10 / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000276:immunology* / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013047:Specific Pathogen-Free Organisms; D051197:Toll-Like Receptor 4 / Q000032:analysis; D051217:Toll-Like Receptor 9 / Q000032:analysis
chemical_list: D039481:CD11b Antigen; D018956:CD5 Antigens; C526836:Cd5 protein, mouse; C556062:IL10 protein, mouse; D007075:Immunoglobulin M; C493487:Tlr4 protein, mouse; C495370:Tlr9 protein, mouse; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D016753:Interleukin-10; D016264:Dextran Sulfate