Enteroantigen-presenting B cells efficiently stimulate CD4+ T cells in vitro

✍ Scribed by Esben Gjerløff Wedebye Schmidt; Nanna Ny Kristensen; Mogens Helweg Claesson; Anders Elm Pedersen

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 766 KB
• Volume: 17
• Category: Article
• ISSN: 1078-0998
• DOI: 10.1002/ibd.21429

✦ Synopsis

Background: Presentation of enterobacterial antigens by antigen-presenting cells and activation of enteroantigen-specific CD4 þ T cells are considered crucial steps in inflammatory bowel disease (IBD) pathology. The detrimental effects of such CD4 þ T cells have been thoroughly demonstrated in models of colitis. Also, we have previously established an in vitro assay where murine enteroantigen-specific colitogenic CD4 þ CD25 À T cells are activated by splenocytes pulsed with an enterobacterial extract.

Methods: CD4 þ CD25 À T cells were stimulated in vitro with various kinds of enterobacterial extract-pulsed antigen-presenting cells. T-helper phenotypes were detected by flow cytometry.

Results:

We found that enteroantigen-pulsed splenic B cells possess a significantly higher and more sustained T cell stimulatory capacity than similarly pulsed splenic dendritic cells (DCs) measured by the level of enteroantigen-specific CD4 þ CD25 À T cell proliferation. In support of this, we observed upregulation of classic maturation markers in B cells following incubation with enterobacterial antigens. Peritoneal and mesenteric lymph node-derived B cells were equally effective as enteroantigen-presenting stimulator cells. B cells greatly expanded the number of stimulated CD4 þ T cells, which acquired a T H 2 phenotype. Interestingly, regulatory T cells were primarily activated by enteroantigen-pulsed B cells but not by similarly pulsed DCs.

Conclusions:

We conclude that B cells are superior stimulators of enteroantigen-specific CD4 þ T cells in vitro, favoring T H 2 polarization. Thus, enteroantigen-processing and -presentation by B cells instead of by DCs might have opposing consequences for IBD development.