[Properties of T-cell growth factor obtained from diucifon-stimulated human lymphocytes]

The properties of T-cell growth factor (TCGF), obtained by diucifon (Dc) stimulation of human mononuclear cells (MNC) (TCGF-Dc) have been studied. Taking into account the fact that Dc alone does not, like other TCGF inductors, cause proliferation, differences between TCGF-Dc and TCGF were suggested. Partial purification of supernatant from cells, activated by Dc was performed on Sephadex G-100 column. TCGF-Dc biological activity in these fractions was determined in the system of mitogen activated human MNC and mice thymocytes, as well as in the system of concanavalin A transformed cells. 2 peaks of TCGF-Dc activity have been revealed that are indicative of TCGF-Dc molecular mass heterogeneity. In contrast to TCGF, low molecular mass TCGF-Dc (8000-12000) and TCGF-Dc from the whole supernatant were capable of absorbing on intact human MNC. TCGF-Dc may be constantly present on MNC membrane, but TCGF-Dc fixation is not sufficient for proliferation induction, the receptor activation is necessary as well. Receptors to TCGF-Dc were suggested to consist of fixing and triggering sites.