title: Repopulation kinetics of intestinal intraepithelial lymphocytes in murine bone marrow radiation chimeras.
abstract: The kinetics of lymphoid cell repopulation of murine intestinal intraepithelial lymphocytes (IEL) from BM stem cells were studied in F1----parent radiation chimeras and were compared with T cell repopulation of the thymus and the spleen. T cells arising from donor bone marrow were present in the gut epithelium as early as day 5 postreconstitution in radiation chimeras. By day 7 postreconstitution, and at times thereafter, the IEL consisted of 70-95% CD3+ donor bone marrow-derived T cells, most of which were CD8+ cells with variable Thy-1 expression. CD4+8- IEL also were detected between days 7 and 14 postreconstitution; however, the CD4+8+ IEL subset did not appear within the gut epithelium until several weeks later and was followed by a progressive increase in the intensity of CD8 expression on CD4+8+ IEL. Functionally mature T cell receptor gamma/delta + and alpha/beta + IEL were present throughout repopulation of the gut epithelium. In contrast to the IEL, T cells were not detected in the thymus or the spleen until days 14 and 21 postreconstitution, respectively, and evidence of T cell function in the spleen was not detected until day 21 postreconstitution. These findings have implications for human bone marrow transplantation in that they demonstrate that T cell repopulation of the gut epithelium begins prior to T cell repopulation of the thymus and the spleen, and indicate that even in the presence of a thymus some IEL proceed through an extrathymic developmental pathway.
authors.affiliation: Department of Biological Science, University of Tulsa, Oklahoma 74104.
authors.forename: R L
authors.initials: RL
authors.lastname: Mosley
authors.forename: J R
authors.initials: JR
authors.lastname: Klein
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology; D005434:Flow Cytometry; D007422:Intestines / Q000166:cytology / Q000276:immunology*; D008214:Lymphocytes / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011828:Radiation Chimera; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis; D013154:Spleen / Q000276:immunology
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta