Thymocyte clones from 14-day mouse embryos. I. State of T cell receptor genes, surface markers, and growth requirements.
We have established in culture 13 clones from the thymus of a 14-d B10.BR mouse embryo and characterized 8 of them. All eight FT clones have the TCR-gamma and -beta genes in germline configuration. They express mRNA for the gamma, but not for the beta nor the alpha genes. All eight FT clones are Thy-1+, Ly-1+, LFA-1+, Pgp-1+, H-2K+, and T3-. Three phenotypes could be distinguished on the basis of Lyt-2, L3T4, and IL-2-R expression: Lyt-2+, L3T4-, IL-2-R+ (I); Lyt-2+, L3T4-, IL-2-R- (II); and Lyt-2+, L3T4+, IL-2-R+ (III) cells. All eight clones grow in rIL-4 and six clones also proliferate in rIL-2. Antibodies specific for IL-2-R inhibit their response to rIL-2 but not to rIL-4. The eight FT clones synthesize mRNA for IL-4 after stimulation in vitro and none of them exhibit cytolytic activity or helper function for B lymphocytes. We conclude that the FT clones are at a very early stage of T cell development, that the expression of Lyt-2 and L3T4 surface molecules can precede that of the antigen receptor, and that the same fetal thymocyte can use both IL-4 and IL-2 as growth factor.
D000818:Animals; D000950:Antigens, Ly / Q000235:genetics; D000954:Antigens, Surface / Q000235:genetics*; D002455:Cell Division; D002478:Cells, Cultured; D002999:Clone Cells; D004622:Embryo, Mammalian; D007376:Interleukin-2 / Q000235:genetics / Q000494:pharmacology; D015847:Interleukin-4; D007378:Interleukins / Q000235:genetics / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000950:Antigens, Ly; D000954:Antigens, Surface; D007376:Interleukin-2; D007378:Interleukins; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D015847:Interleukin-4; D013755:Tetradecanoylphorbol Acetate