CYTOKINES INVOLVING GP130 IN SIGNAL-TRANSDUCTION SUPPRESSED GROWTH OFA MOUSE HYBRIDOMA CELL-LINE AND ENHANCED ITS ANTIBODY-PRODUCTION

Three cytokines, interleukin 6 (IL-6), leukaemia inhibitory factor (LI F), and oncostatin M (OSM), that bind to composite receptors including a common signal transducer gp130 suppressed proliferation of a mouse B-cell hybridoma cell line 2E3-O cultured in serum-free medium, while they enhanced antibody production of the cells. The specific growth ra te of the cells reduced from 1.0/day for control to 0.6/day for the cu ltures supplemented with IL-6, LIF, or OSM at 1, 4, or 2 ng/ml, respec tively. The antibody productivity increased five-fold when the cells w ere cultured with IL-6, LIF, or OSM at 1, 25, or 20 ng/ml, respectivel y. Transforming growth factor beta 1(TGF-beta 1) similarly suppressed growth of the cells at the concentration of 5 ng/ml, while it did not enhance the antibody production. Cell cycle analysis revealed that IL- 6 induced the cells to be arrested at G(1) phase of the cell cycle mor e intensively than TGF-beta 1, indicating that IL-6 and TGF-beta 1 sup pressed the growth through mutually different mechanisms. As a whole, this work suggests that gp130, which is commonly involved in each rece ptor for IL-6, LIF, and OSM, transduces signals for suppressing prolif eration and possibly for enhancing antibody production in the hybridom a cells.