Multiple activities of a cloned cell line mediating natural killer cell function.

Abstract

Natural killer (NK) cell lysis of target cells does not require deliberate immunization by tumor cells. Although these cells can be distinguished from conventional T cells, B cells and phagocytic cells, they have been difficult to define. A representative cloned cell line that was obtained by cloning Ig-Ly-5+ cells from spleen is described. This clone, Cl.Ly-1-2-NK-1+/11, displays Thy-1, Ly-5, Qat-4, Qat-5 and NK-1 cell surface antigen and lyses the NK-sensitive YAC-1 lymphoma cells but does not lyse RL-12 cells, an NK-resistant lymphoma. This clone lysed the P815 mastocytoma, EL4 lymphoma and [Escherichia coli] lipopolysaccharide-activated B lymphocyte targets. This cloned population therefore combined information for a unique display of cell surface antigens and specialized function similar to activated NK cells. Because this cloned population forms conjugates with susceptible but not resistant target cells, it may prove useful to identify the structure of cell surface molecules that recognize foreign cells. Cells of this clone also specifically lysed target cells coated by antibodies to determinants on the target cell surface, demonstrating that a single cloned cell population can mediate 2 specialized immunologic functions: antibody-dependent cellular cytotoxicity and NK cell lysis.