Enrichment of c-kit+ Lin- haemopoietic progenitor cells that commit themselves to extrathymic T cells in in vitro culture of appendix mononuclear cells.
The appendix as well as the small intestine have recently been found to carry c-kit+ stem cells which give rise to extrathymic T cells. In this study, the properties of c-kit+ stem cells in the appendix of mice were further characterized. When appendix mononuclear cells (MNC) were cultured in the presence of stem cell factor, interleukin-3, interleukin-6 and erythropoietin on a methylcellulose culture plate, the population of c-kitdull Lin- and that of c-kithi Lin- cells expanded. Morphological study revealed that these c-kithi Lin- cells were basophilic granular cells (possibly mast cells). Both populations of cultured appendix MNC were then injected into severe combined immunodeficient mice or cultured with Tst-4 thymic stroma cells. These in vivo and in vitro studies demonstrated that c-kitdull Lin- cells were oligopotent haemopoietic progenitor cells which gave rise to extrathymic T cells, while c-kithi Lin- cells lacked haemopoietic progenitor cell activity. In contrast to c-kit+ stem cells in the bone marrow, those in the appendix did not give rise to myeloid cells and conventional thymic T cells under any of the conditions tested. The present results suggest that the appendix primarily comprises c-kit+ cells which give rise to basophilic granular cells and extrathymic T cells and that such c-kit+ cells have the ability to replicate themselves in culture in vitro.
Koya
T
T
Department of Immunology; Second Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan.
Honda
S
S
Narita
J
J
Watanabe
H
H
Arakawa
M
M
Abo
T
T
D000818:Animals; D001065:Appendix / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D019009:Proto-Oncogene Proteins c-kit