Effectivein vivo induction of lymphokine-activated killer (LAK) cells by pretreatment with a streptococcal preparation, OK-432

Publisher Website
Google Scholar
Abstract
Effects of a streptococcal preparation, OK-432, on precursors of lymphokine-activated killer (LAK) cells were observedin vivo. Total number of splenocytes and the ratio of asGM 1 + cells increased gradually after i.v. administration of OK-432, reaching their peaks at 3 to 4 days. It was found that as GM 1 + cells were nonadherent and large in size. There were little differences in the ratios of Thy-1+, Lyt-2+, and L3T4+ cells before and after OK-432 treatment. Mice were injected i.p. with recombinant interleukin 2 (rIL-2) at a dose of 5 × 104 U per mouse 4 days after OK-432 administration and LAK activity in their splenocytes was examined using natural killer (NK) resistant EL-4 target cells. Splenocytes in mice treated with both OK-432 and rIL-2 showed higher LAK activity than those in mice treated with rIL-2 alone.In vivo treatment with anti asGM, antibody prior to rIL-2 injection abolished completely such augmentation of LAK activity in OK-432 treated mice. These results demonstrated that asGM 1 + LAK precursor cells induced by OK-432 were effectively differentiated into LAK cells by rIL-2.