title: Apathogenic, intestinal, segmented, filamentous bacteria stimulate the mucosal immune system of mice.
abstract: Segmented filamentous bacteria (SFBs) are apathogenic autochthonous bacteria in the murine small intestine that preferentially attach to Peyer's patch epithelium. SFBs have never been cultured in vitro. We have studied the effects of SFBs on the immune system of the host. Mice monoassociated with SFBs were compared with germ-free mice and with mice without SFBs but with a specific-pathogen-free (SPF) gut flora. SFBs versus no microbial flora raised the number of lymphoid cells in the lamina propria of the ileal and cecal mucosa, raised the number of immunoglobulin A (IgA)-secreting cells in the intestinal mucosa, produced elevated IgA titers in serum and intestinal secretions, and enhanced the concanavalin A-induced proliferative responses of mesenteric lymph node cells. The SPF flora had effects similar to but less pronounced than those mediated by SFBs. The results indicate that SFBs stimulate the mucosal immune system to a greater extent than do other autochthonous gut bacteria.
authors.affiliation: Central Animal Laboratory, Catholic University, Nijmegen, The Netherlands.
authors.forename: H L
authors.initials: HL
authors.lastname: Klaasen
authors.forename: P J
authors.initials: PJ
authors.lastname: Van der Heijden
authors.forename: W
authors.initials: W
authors.lastname: Stok
authors.forename: F G
authors.initials: FG
authors.lastname: Poelma
authors.forename: J P
authors.initials: JP
authors.lastname: Koopman
authors.forename: M E
authors.initials: ME
authors.lastname: Van den Brink
authors.forename: M H
authors.initials: MH
authors.lastname: Bakker
authors.forename: W M
authors.initials: WM
authors.lastname: Eling
authors.forename: A C
authors.initials: AC
authors.lastname: Beynen
mesh_terms: D000818:Animals; D001424:Bacterial Infections / Q000276:immunology*; D002432:Cecum / Q000166:cytology / Q000276:immunology; D005243:Feces / Q000382:microbiology; D005856:Germ-Free Life; D007070:Immunoglobulin A / Q000097:blood; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology* / Q000382:microbiology; D007421:Intestine, Small / Q000166:cytology / Q000276:immunology / Q000382:microbiology*; D008213:Lymphocyte Activation; D051379:Mice; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology
chemical_list: D007070:Immunoglobulin A