title: Transforming growth factor-beta 1 (TGF-beta 1) inhibits DNA synthesis of PWM-stimulated PBMC via suppression of IL-2 and IL-6 production.
abstract: The multifunctional cytokine transforming growth factor-beta 1 (TGF-beta 1) is known to inhibit the proliferation of lymphocytes. However, the role of TGF-beta 1 in the production and secretion of various interleukins is not yet clear. In this study we have analysed in parallel the effects of TGF-beta 1 on both DNA synthesis and production of the cytokines IL-1, IL-2, IL-6, and TNF-alpha by pokeweed mitogen-stimulated peripheral blood mononuclear cells. With this stimulation system we show that TGF-beta 1 at a concentration of 15 ng/ml significantly suppresses IL-2 and IL-6 production. The release of IL-1 and TNF-alpha, however, was not influenced under these conditions. Under similar conditions DNA synthesis of PWM-stimulated PBMC was found to be inhibited by 50 +/- 10%. Using flow cytometric methods we could demonstrate that TGF-beta 1 arrested the cells in the G0/G1 phase of the cell cycle. Taken together, these results suggest that TGF-beta 1 may suppress immune responses by inhibiting the endogenous production of IL-2 and IL-6.
authors.affiliation: Department of Internal Medicine, Medical Academy Magdeburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Reinhold
authors.forename: U
authors.initials: U
authors.lastname: Bank
authors.forename: F
authors.initials: F
authors.lastname: Bühling
authors.forename: U
authors.initials: U
authors.lastname: Lendeckel
authors.forename: A J
authors.initials: AJ
authors.lastname: Ulmer
authors.forename: H D
authors.initials: HD
authors.lastname: Flad
authors.forename: S
authors.initials: S
authors.lastname: Ansorge
mesh_terms: D004247:DNA / Q000096:biosynthesis*; D016193:G1 Phase / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000378:metabolism; D010835:Phytohemagglutinins / Q000494:pharmacology; D011043:Pokeweed Mitogens / Q000494:pharmacology*; D016192:Resting Phase, Cell Cycle / Q000187:drug effects; D013268:Stimulation, Chemical; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D007375:Interleukin-1; D007376:Interleukin-2; D015850:Interleukin-6; D010835:Phytohemagglutinins; D011043:Pokeweed Mitogens; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D004247:DNA