K Cell Activity is Independent of Both Thymus and Spleen

Abstract

K cells, mediating antibody-dependent cellular cytotoxicity of nucleated dividing target cells, are highly efficient effectors in the presence of minute amounts of antibody in vitro (MacLennan,1972). Their distinct Fc receptor may now be identified by a monoclonal antibody, B73.1 (Perussia et al.,1983a). The role they may play in vivo, in normal and/or pathological situations remains unknown. K cells may be involved in the lysis of virus-infected cells (Kohl and Moore,1983), and of established tumour cell-lines as Chang cells — Also, sera from patients with chronic active liver disease (Kawanishi and McDermott,1979) rheumatoid arthritis (MacLennan,1969) may mediate ADCC of relevant target cells. Recently, a role of K cells in the regulation of immune responses has been considered. Anti-idiotypes have been shown to be able to mediate ADCC against mouse hybridoma cells (Caraux and Weigle,1983) or plasmocytoma cells (Chassoux and Stanislawski, in preparation). The origin and conditions of maturation of K cells are not known. K/NK cells do not appear to be B cells (Chassoux et al.,1983a). Their relationships with other lymphoid cell lineages has received attention with the development of monoclonal antibodies. Some authors have described common antigens on T and K/NK cells and therefore consider that they are part of the same lineage (Fast, Hansen and Newman, 1981):other reagents, however, may separate T from K/NK cells (Beverley and Callard,1981).