[Comparative characteristics of human interleukin-2 preparations isolated from various sources]

Interleukin-2 (IL-2) was isolated from donor peripheral blood lymphocytes and from JURKAT T-lymphoma cells. The purification procedure including gel filtration on DEAE and CM-Sephadex resulted in a 400-fold increase of the enzyme specific activity. It was shown that optimal proliferation of T-lymphocytes occurs upon consecutive treatment of cells with phytohaemagglutinin and IL-2 as well as in the presence of a serum. The properties and procedure of isolation of the long proliferating line of IL-2-dependent T-cells B-5 were described. Proliferation of B-5 cells completely depended on the presence of IL-2 in the medium, although long-term proliferation occurred upon periodic stimulation of cells with the antigen (allogenic lymphocytes). In the absence of IL-2 B-5 cells decay within 36 hours. The perspective uses of IL-2 prepared from the cultural fluid of human peripheral blood lymphocytes for adoptive immunotherapy of tumours and the applicability of IL-2-dependent B-5 cells for testing the activity of IL-2 preparations from various sources are discussed.