title: IgA production by peritoneal cavity B cells is IL-6 independent: implications for intestinal IgA responses.
abstract: We have shown previously both in vitro and in vivo that IL-6 is an important factor for the development of IgA-producing B cells. However, despite the lack of this cytokine in mice with targeted disruption of the interleukin (IL)-6 gene (gene knockout mice), a substantial number of IgA-producing plasma cells occur in their intestinal mucosa. The experiments reported here indicate that there is a population of IgA-producing B cell precursors originating from the peritoneal cavity, distinguished from conventional Peyer's patch-derived precursors by their expression of CD5, and that IgA secretion by these cells is IL-6-independent. Further, there is an increase in CD5 expression among brightly staining IgA-producing cells obtained from the intestinal lamina propria of IL-6 gene-disrupted mice compared to normal controls. These data suggest an explanation for the persistence of IgA-producing plasma cells in the intestinal mucosa of IL-6-depleted mice and indicate the importance of IL-6 for development of conventional precursors of IgA-producing B cells, but not those derived from the peritoneal cavity pool.
authors.affiliation: Department of Veterinary Pathology, University of Sydney, Australia.
authors.forename: K W
authors.initials: KW
authors.lastname: Beagley
authors.forename: S
authors.initials: S
authors.lastname: Bao
authors.forename: A J
authors.initials: AJ
authors.lastname: Ramsay
authors.forename: J H
authors.initials: JH
authors.lastname: Eldridge
authors.forename: A J
authors.initials: AJ
authors.lastname: Husband
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology; D001402:B-Lymphocytes / Q000276:immunology*; D007070:Immunoglobulin A / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010581:Peyer's Patches / Q000276:immunology
chemical_list: D007070:Immunoglobulin A; D015850:Interleukin-6