Effect of transforming growth factor beta on the EL4 thymoma variant EL4/6.1: dissociation of inhibition of proliferation from expression of IL-1 and IL-2 receptors.
In order to further characterize the action of transforming growth factor beta (TGF-beta) on lymphoid cells, we investigated the effects of porcine TGF-beta 1 and -2 on the IL-1 sensitive EL4/6.1 thymoma cell line. The proliferation of EL4/6.1 thymoma cells was inhibited by TGF-beta 1 and TGF-beta 2 (1 ng/ml) to a similar degree, the population doubling time was increased by 50-60%, total inhibition was not achieved. This decrease of proliferation was associated with an increase of the number of cells in the G0/G1 compartment of the cell cycle. TGF-beta-mediated inhibition could not be overcome by adding exogenous rIL-1 nor was the binding capacity for IL-1 reduced. In addition, TGF-beta did not interfere with the induction of IL-2 receptors by a combination of Ionomycin+PMA+IL-1. The data suggest that TGF-beta mediated inhibition of thymocyte/lymphocyte proliferation is not associated with an inhibition of the expression or the induction of expression of IL-2 or IL-1 receptors.
Stoeck
M
M
Ludwig Institute for Cancer Research, Lausanne Branch, Epalinges, Switzerland.
Howe
R C
RC
Miescher
S
S
von Fliedner
V
V
MacDonald
H R
HR
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D007375:Interleukin-1 / Q000494:pharmacology; D015759:Ionomycin / Q000494:pharmacology; D051379:Mice; D011971:Receptors, Immunologic / Q000096:biosynthesis*; D017472:Receptors, Interleukin-1; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013945:Thymoma / Q000473:pathology; D013953:Thymus Neoplasms / Q000473:pathology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects* / Q000473:pathology
D007375:Interleukin-1; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate