title: The failure of oral tolerance induction is functionally coupled to the absence of T cells in Peyer's patches under germfree conditions.
abstract: Although intestinal bacterial flora has been thought to play a role in the induction of oral tolerance, the mechanism has yet to be elucidated. We therefore examined the bacterial flora-dependent acquisition of susceptibility to oral tolerance induction using a gnotobiotic murine model. Germ-free (GF) mice exhibited a significant shortage of T cells in the PPs in comparison to SPF mice. A recovery in the number of such T cells was accomplished in the gnotobiotic mice associated with Bifidobacterium infantis or Escherichia coli but not in the gnotobiotic mice with Clostridium perfringens or Staphylococcus aureus. To examine the susceptibility to oral tolerance induction, these mice were orally given ovalbumin (OVA) as a tolerogen and then injected i.p. with the Ag. The Ag-specific IgG1 in the serum remained at a low level in both SPF and those gnotobiotic mice groups containing a sufficient number of T cells in the PPs. However, no such unresponsiveness in the Ab response was observed in GF or the other gnotobiotic mice groups containing only a few T cells in the tissues. Adoptive cell transfer analysis clearly showed that a sufficient number of T cells in the PPs is required for the induction of oral tolerance. Furthermore, the reduced expression of SLC (secondary lymphoid-tissue chemokine), which is responsible for T-cell migration to lymphoid organs, was observed in the PPs of GF mice, resulting in a shortage of T cells in the tissues. However, the reduced expression of SLC was restored even in the GF mice after conventionalization, thus suggesting that the failure of oral tolerance induction is functionally coupled to the innate absence of T cells under the GF condition.
authors.affiliation: Department of Infectious Diseases, Tokai University School of Medicine, Isehara, Kanagawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Maeda
authors.forename: S
authors.initials: S
authors.lastname: Noda
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Sawamura
authors.forename: Y
authors.initials: Y
authors.lastname: Aiba
authors.forename: H
authors.initials: H
authors.lastname: Ishikawa
authors.forename: H
authors.initials: H
authors.lastname: Hasegawa
authors.forename: N
authors.initials: N
authors.lastname: Kawabe
authors.forename: M
authors.initials: M
authors.lastname: Miyasaka
authors.forename: Y
authors.initials: Y
authors.lastname: Koga
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001644:Bifidobacterium / Q000276:immunology; D054421:Chemokine CCL21; D019742:Chemokines, CC / Q000276:immunology; D003016:Clostridium perfringens / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D015870:Gene Expression; D007108:Immune Tolerance / Q000276:immunology*; D018655:Lymphocyte Count; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology*; D013047:Specific Pathogen-Free Organisms; D013211:Staphylococcus aureus / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
chemical_list: C515479:Ccl21c protein, mouse; D054421:Chemokine CCL21; D019742:Chemokines, CC; D010047:Ovalbumin