DEVELOPMENT OF HUMAN INTERLEUKIN-7 IMMUNOAFFINITY PURIFICATION METHOD

The article presents the results of the comparative development of different variants of immunoaffinity sorbents for the purification of human IL-7, namely: Sepharose 6B and sol-gel materials based on tetraethoxysilane (TEOS). The optimal conditions for the synthesis of a chromatographic sorbent based on TEOS, which provide acceptable characteristics of the immobilization of a biological substance, were experimentally established. The sorbent based on TEOS and Sepharose 6B provide identical characteristics for the sorption of antibodies after 12 hours of the experiment. To establish rational conditions for immunoaffinity chromatography, various combinations of sorbents, anti-IL-7 monoclonal antibodies, and elution solutions were studied. It was shown that a variant of immunoaffinity chromatography based on TEOS sorbent using 325D2 anti-IL-7 monoclonal antibodies and 4M magnesium chloride solution as eluate, is more effective. Immunochromatographic columns synthesized on the basis of Sepharose 6B and TEOS are characterized by high recovery rates (at least 95%) in a wide range of human IL-7 concentrations (0.05...20 μg/ml), however, the column based on Sepharose 6B is less than stable with repeated use (more than 12 cycles without regeneration). The developed method makes it possible to obtain recombinant human IL-7 with a purity of 98%.