Interleukin-3 (IL-3) can promote the proliferation of certain classes of lymphocytes distinct from those that are dependent on interleukin-2 (IL-2) for growth. Culture conditions for its production are identical to those required for IL-2 and in both cases the producer cell appears to be Thy 1.2+, Lyt1+, Lyt2- However, unlike the IL-2 responder cells, the cells that proliferate in IL-3 are generally Lyt2-. Here we have measured the natural cytotoxic (NC) activity as well as natural killer (NK) cell activity of the IL-3-dependent cells. Both of these activities are part of a repertoire of spontaneous cytotoxic functions found in mice that might serve in early defence against infectious agents or immunosurveillance against tumours in vivo. We report a new finding that IL-3 selectively maintains NC cells but not NK cells in culture. This is in contrast to the known requirement for IL-2 in NK cell growth. This provides a means of isolating NC cells from NK cells in the mouse as an initial step in the study of the relative contribution of these two cell types in tumour immunity.
Vindesine (VDS), a structural analogue of Vinca Alkaloids, was found to increase the NK-mediated cytolytic effects of mouse lymphocytes against human K562 target cells in a 18-hr assay. Pretreatment of effector or target cells with the drug did not affect substantially the NK reaction. The phenomenon has been detected using splenocytes of either congenitally athymic or conventional euthymic mice of different strains. Effector lymphocytes deprived of cells adherent to plastic surface or to nylon-wool column were still competent for drug-mediated increase of NK function. It is suggested that modification of the membrane make-up of effector or target cells reversibly induced by VDS, would promote higher NK-mediated cytolytic effects.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.