title: Intestinal intraepithelial TCRγδ⁺ T cells are activated by normal commensal bacteria.
abstract: TCRγδ(+) T cells play a critical role in protecting the intestinal mucosa against pathogenic infection. In the absence of infection, TCRγδ(+) T cell activation must be continuously regulated by T regulatory cells (Treg) to prevent the development of colitis. However, the activation of intestinal TCRγδ(+) T cells under normal conditions has not been clearly resolved. In order to determine TCRγδ(+) T cell activation in vivo, we designed an NF-κB based reporter system. Using the recombinant lentiviral method, we delivered the NF-κB reporter to isolated TCRγδ(+) T cells, which were then adoptively transferred into normal mice. Our data indicate that the NF-κB activation level in TCRγδ(+) T cells is higher in the intestinal intraepithelial layer than in the lamina propria region. In addition, the surface expression level of lymphocyte activation marker CD69 in TCRγδ(+) T cells is also higher in the intestinal intraepithelial layer and this activation was reduced by Sulfatrim treatment which removes of commensal bacteria. Collectively, our data indicate that the TCRγδ(+) T cell population attached to the intestinal lumen is constitutively activated even by normal commensal bacteria.
authors.affiliation: School of Life Sciences and Bioimaging Research Center, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea.
authors.forename: Sang Phil
authors.initials: SP
authors.lastname: Jeong
authors.forename: Jung-Ah
authors.initials: JA
authors.lastname: Kang
authors.forename: Sung-Gyoo
authors.initials: SG
authors.lastname: Park
mesh_terms: D000818:Animals; D001419:Bacteria / Q000276:immunology*; D001422:Bacterial Adhesion; D018407:Bacterial Physiological Phenomena; D007413:Intestinal Mucosa / Q000276:immunology* / Q000382:microbiology; D007422:Intestines / Q000276:immunology* / Q000382:microbiology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000235:genetics / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*
chemical_list: D016328:NF-kappa B; D016692:Receptors, Antigen, T-Cell, gamma-delta