title: Identification and characterization of lymphoid precursors in the murine intestinal epithelium.
abstract: Although in vivo evidence supports a role for the murine intestinal epithelium in the extrathymic generation of certain intraepithelial T lymphocytes (IEL), no intraepithelial cells with in vitro lymphoid progenitor potential have yet been demonstrated. Using reaggregate fetal thymic organ culture techniques, we show that a subset of CD3(-) cells isolated from the intestinal epithelium of young mice is capable of generating T cells (alpha beta and gamma delta) and NK1.1(+) cells in vitro. A novel IEL subset bearing a low level of CD45 was identified and found to comprise cells expressing highly immature lymphoid markers including CD34, c-kit, CD122, CD127 and high levels of CD16 and CD44. This subset represents 20-30% of intraepithelial CD45(+) cells from 4-week-old wild-type and nude mouse strains and contains cells with in vitro T cell differentiation capacity. The identification of such an early pluripotent precursor phenotype within the intestinal epithelium implies that the potential for T cell generation exists at this site, and suggests that extrathymic T cell generation may occur within the epithelium itself.
authors.affiliation: Walsgrave Hospital, Coventry, Warwickshire, GB. jmwoodward@doctors.org.uk
authors.forename: J
authors.initials: J
authors.lastname: Woodward
authors.forename: E
authors.initials: E
authors.lastname: Jenkinson
mesh_terms: D000818:Animals; D017252:CD3 Complex / Q000032:analysis; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D016130:Immunophenotyping; D007413:Intestinal Mucosa / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000032:analysis; D051379:Mice; D008806:Mice, Inbred AKR; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009924:Organ Culture Techniques; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D017252:CD3 Complex; D017493:Leukocyte Common Antigens