title: Origins of intestinal intraepithelial lymphocytes: direct evidence for a thymus-derived gamma delta T cell component.
abstract: The contribution of T cell precursors from the thymus and the bone marrow to the pool of intestinal intraepithelial lymphocvtes (IELs) has been studied in a system using donor cells from enhanced-green fluorescent protein (EGFP+ ) transgenic mice a doptively transferred into EGFP- recipient mice. Consistent with previous studies, regeneration of gamma delta and alpha beta T cell populations in the intestinal epithelium occurred within 2-3 weeks of bone marrow transfer into irradiatiated EGFP- animals and prior to T cell repopulation of the spleen, of interest, however, although transfer of whole adult EGFP+ thymocytes to non-irradiated EGFP- congenitally-athymic nude mice produced alpha beta T cells in both the spleen and intestine. Gamma delta T cells in significant number were detected only in the intestine of recipient mice. In contrast, transfer of CD3-, CD4-, CD8- immature thymocytes resulted in no detectable T cells in either the intestine or the spleen of nude mice up to twelve weeks post-cell transfer, suggesting that intestinal IELs generated from thymocytes arose from differentiated lineage-committed cells rather than from immature thymocytes. These findings provide direct evidence for both thymus-independent and thymus-dependent sources of intestinal gamma delta T cells, and they suggest that murine IELs consist of diverse groups of T cells with distinct developmental origins.
authors.affiliation: Department of Biological Science, University of Tulsa, OK, USA.
authors.forename: E U
authors.initials: EU
authors.lastname: Bagriacik
authors.forename: M
authors.initials: M
authors.lastname: Okabe
authors.forename: J R
authors.initials: JR
authors.lastname: Klein
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology; D005260:Female; D049452:Green Fluorescent Proteins; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology*; D019891:Leukopoiesis; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000502:physiology; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology* / Q000502:physiology
chemical_list: D008164:Luminescent Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D049452:Green Fluorescent Proteins