[Cellular regulation of human lymphocyte mitogenic factor release in vitro]. / Kletochnaia reguliatsiia vydeleniia mitogennogo faktora limfotsitov cheloveka in vitro.

Production of the mitogenic facotr by human lymphocytes stimulated with phytohemagglutinin (PHA) was investigated. Anti-PHA antibodies were used for studying the culture medium mitogenic activity. The mitogenic factor production markedly increased after lymphocyte irradiation. When macrophages were eliminated, using iron powder, mitogenic factor generation was also increased. It was demonstrated that lymphocyte irradiation and macrophage elimination stimulated the mitogenic factor production throgh different mechanisms.

[Physicochemical properties of the human lymphocyte mitogenic factor induced by phytohemagglutinin]. / Fiziko-khimicheskie svoistva mitogennogo faktora limfotsitov cheloveka, indutsirovannogo fitogemaggliutininom

Some physical and chemical properties of the mitogenic factor (MF) produced in vitro by PHA-stimulated human lymphocytes were investigated. Treatment of the culture medium with proteases proved to decrease the MF activity sharply. The MF was found to have an elution pattern in Sephadex and Bio-gel gels similar to proteins with the molecular weight of 20 000--30 000 daltons (peak--25 000). In experiments with the MF fractionation by disc-electrophoresis on 5% polyacylamide gel the MF formed a few discrete peaks in the fractions corresponding to the mobility of alpha1- and alpha2-globulins and transferrin. In isoelectric focusing the MF formed 3 fractions in the pH range of 4.5--8.3. Functional heterogeneity of the MF is suggested.

[Effect of inhibitors of DNA and protein synthesis on production of mitogenic factor by human lymphocytes stimulated with phytohemagglutinin]. / Vliianie ingibitorov sinteza DNK i belka na produktsiiu mitogennogo faktora limfotsitami cheloveka, stimulirovannymi fitogemmaggliutininom

A study was made of the influence of DNA and protein synthesis inhibitors on the production of mitogenic factor (MF) by human lymphocytes stimulated with phytohemagglutinin. Inhibition of the DNA synthesis with mitomycin failed to decrease MF production but in inhibiting the protein synthesis MF factor production was even increased. A conclusion was drawn that MF preexisted in the lymphoid cell before the beginning of stimulation, not in the ready from but as an inactive precursor; it became activated only in the living cells stimulated with phytohemagglutinin no protein synthesis is required at that moment.