Selective growth of natural cytotoxic but not natural killer effector cells in interleukin-3.
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.
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D007372:Interferons / Q000494:pharmacology; D007377:Interleukin-3; D007694:Killer Cells, Natural / Q000276:immunology / Q000502:physiology*; D008222:Lymphokines / Q000502:physiology*; D051379:Mice; D013154:Spleen / Q000166:cytology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000502:physiology*
D000954:Antigens, Surface; D007377:Interleukin-3; D008222:Lymphokines; D007372:Interferons