title: Mitogen-activated Xenopus laevis lymphocytes produce a T-cell growth factor.
abstract: Mitogen-free and serum-free supernatants (SNs) from cultures of phytohaemagglutinin (PHA)-stimulated Xenopus splenocytes, co-stimulated thymocytes, induced proliferation of splenic and thymic lymphoblast and supported growth of alloreactive T-cell lines. These SNs had no effect on 'resting' splenocytes, as measured by uptake of tritiated thymidine ([3H]TdR). Growth-promoting activity was also detected in SNs of cultures containing alloreactive T-cell lines and either PHA or irradiated stimulator cells that expressed the original priming alloantigens. Thus, T lymphocytes appear to be involved in producing, as well as responding to, a Xenopus T-cell growth factor (TCGF). TCGF activity could be absorbed from these active SNs with PHA-activated splenic blasts. No functional cross-reactivity among different mammalian interleukin-2 (IL-2) and Xenopus TCGF preparations was detected.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003429:Cross Reactions; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D010835:Phytohemagglutinins / Q000494:pharmacology; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D014982:Xenopus laevis / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D010835:Phytohemagglutinins