[Roles of thymic epithelial cells in generation of NK-T cells from aly/aly mouse].
NK1.1+ TCR alpha/beta+ (NK-T) cells are markedly reduced in the alymphoplasia mutant mouse. We have previously shown that the defect resides in the thymic environment where the NK-T precursors develop but not in the precursor cells themselves. In the present study to elucidate the recipient factor(s) that is responsible for the development of NK-T cells, radiation bone-marrow chimeras were established by using alymphoplasia mutant mice as a donor strain and either beta 2 microglobulin knock-out (beta 2m-/-) or CD1d1-/- mice as recipients, both of which lack CD1 molecules. It was shown that substantial numbers of NK-T cells with typical surface phenotypes were generated both in the thymus and the spleen of the chimeras. The NK-T cells produced equivalent or slightly elevated levels of IL-4 and IFN-gamma in response to an immobilized anti-CD3 monoclonal antibody. These findings suggested that expression of beta 2m-associated ligands, namely CD1 molecules, on the thymic epithelium was not necessarily an essential requisite for the NK-T cell development. Furthermore, we demonstrate herein that the intrathymic transfer of a medullary thymic epithelial cell line of normal mouse can rescue the generation of the NK-T cells in the thymus of alymphoplasia mouse. These results demonstrate that function(s) represented by certain types of thymic epithelial cells is indispensable for development of NK-T cells.
Konishi
J
J
First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
D000818:Animals; D018949:Antigens, CD1; D002454:Cell Differentiation; D002455:Cell Division; D004847:Epithelial Cells / Q000502:physiology*; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D007694:Killer Cells, Natural / Q000166:cytology* / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D013950:Thymus Gland / Q000166:cytology*
D018949:Antigens, CD1; D015847:Interleukin-4; D007371:Interferon-gamma