Growth regulatory effects of transforming growth factor-beta 1 and interleukin-2 on IL-2 dependent CD4+T lymphoblastoid cell line.
Transforming growth factor-beta 1 (TGF-beta 1) is an immuno-modulatory cytokine which has been shown to modulate the activity of T and B cells. We show here that human TGF-beta 1 inhibited stationary cultures of IL-2 dependent CD4+ bovine lymphoblastoid T cells (BLTC) by down-regulating their IL-2 receptor (IL-2R) expression, arresting cells in the G0/G1 compartment of the cell cycle, and inducing these cells to undergo apoptosis. These events were reversed by the addition of a minimal concentration of IL-2 (2U/ml). In the presence of exogenous IL-2, TGF-beta 1 was found to augment the proliferative response of BLTC through up-regulation of IL-2R expression, allow progression of normal cell cycle, and significantly prevent apoptosis. Our data clearly show that IL-2 and TGF-beta 1, when present alone, have contrasting effects on BLTC. TGF-beta 1 down regulates events that are associated with IL-2 mediated signal. But when present together, IL-2 and TGF-beta 1 upregulate activation signals and proliferation of rapidly dividing CD4+T cells.
Ayoub
I A
IA
Department of Pathobiolgy, University of Connecticut Storrs 06269-3089, USA.
Yang
T J
TJ
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001792:Blood Platelets / Q000737:chemistry; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects*; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004249:DNA Damage; D004261:DNA Replication / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D011994:Recombinant Proteins / Q000494:pharmacology; D016192:Resting Phase, Cell Cycle / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta