PLoS ONE (Jan 2016)

Decreased Frequency of Intestinal Regulatory CD5+ B Cells in Colonic Inflammation.

  • Yoshiyuki Mishima,
  • Shunji Ishihara,
  • Akihiko Oka,
  • Nobuhiko Fukuba,
  • Naoki Oshima,
  • Hiroki Sonoyama,
  • Noritsugu Yamashita,
  • Yasumasa Tada,
  • Ryusaku Kusunoki,
  • Ichiro Moriyama,
  • Takafumi Yuki,
  • Kousaku Kawashima,
  • Yoshikazu Kinoshita

DOI
https://doi.org/10.1371/journal.pone.0146191
Journal volume & issue
Vol. 11, no. 1
p. e0146191

Abstract

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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. CONCLUSION:A persistent altered mucosal B cell population caused by chronic gut inflammation may be involved in the pathogenesis of inflammatory bowel diseases.