title: Activation of human lymphocytes by supernatants from human thymic epithelium.
abstract: Supernatants from human thymic epithelial cells (TS) were found to have a mitogenic effect on cultured human peripheral blood mononuclear cells and to potentiate their responses to lectins. This was not observed with culture supernatants from the human cell lines AV-3 and HeLa or from the murine cell line L-929. The maximum potentiating effects were observed with pokeweed mitogen (PWM) and phytohaemagglutinin (PHA), whereas the response to concanavalin A (Con A) was only slightly enhanced. TS also potentiated the mixed lymphocyte culture (MLC) response of normal T cells and thymocytes cultured with mitomycin C-treated B lymphoid cell lines. The mitogenic effect of TS was time-dependent and paralleled the appearance of lymphoid colonies in semi-solid agar. Chromatographical separation of concentrated serum-free TS on Sephadex G-100 yielded an active fraction of molecular weight 15,000--25,000 which had all the activities of unseparated TS.
mesh_terms: D002478:Cells, Cultured; D005591:Chemical Fractionation; D002648:Child; D002675:Child, Preschool; D003208:Concanavalin A / Q000494:pharmacology; D004847:Epithelial Cells; D006801:Humans; D007223:Infant; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes; D008970:Molecular Weight; D010835:Phytohemagglutinins / Q000494:pharmacology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013950:Thymus Gland / Q000166:cytology* / Q000254:growth & development
chemical_list: D010835:Phytohemagglutinins; D011043:Pokeweed Mitogens; D003208:Concanavalin A