title: Enhanced generation of OK-432-induced killer cells by interleukin 2.
abstract: Spleen cells of untreated mice became nonspecifically cytotoxic after cultivation in the presence of a streptococcal preparation, OK-432, for 3 or more days. The cytotoxic cells, named OK-432-induced killer (OIK) cells, injured a variety of target cells including syngeneic EL-4 cells resistant to natural killer (NK) cells, but not NK-susceptible YAC-1 cells. C57BL/6 splenic cells cultured for 5 days in the presence of both OK-432 and interleukin 2 (IL-2) were highly cytotoxic to both EL-4 and YAC-1 cells, and had Thy-1+, Lyt-1,2-, and asialogGM1+ phenotypes, which were identical with those of OIK cells. A test for competitive inhibition with cold target cells and fractionation by centrifugation onto discontinuous density gradients of Percoll showed that cytotoxic cells generated by OK-432 plus IL-2 comprised at least two populations; the cells in the first population were cytotoxic to EL-4 cells but not to YAC-1 cells, and were smaller in size than those in the second population, which were cytotoxic to YAC-1 cells and had NK morphology. Therefore, generation of OIK cells was augmented by IL-2.
mesh_terms: D000818:Animals; D001688:Biological Products / Q000494:pharmacology*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004306:Dose-Response Relationship, Immunologic; D004357:Drug Synergism; D007376:Interleukin-2 / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D008223:Lymphoma / Q000276:immunology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010844:Picibanil / Q000494:pharmacology*; D013154:Spleen / Q000276:immunology
chemical_list: D001688:Biological Products; D007376:Interleukin-2; D010844:Picibanil