Selective defect of natural killer and killer cell activity against lymphomas in SJL mice: Low responsiveness to interferon inducers

Three unrelated inbred strains of H-2(s) mice, SJL/JN, A.SW, and B10.S, were classified according to the levels of splenic NK activity against susceptible lymphoma targets, with or without prior administration of the interferon (IFN) inducer p-I:C to the prospective donors of splenocytes: 1) SJL/JN had low endogenous activity that responded poorly to p-I:C-induced augmentation; 2) A.SW exhibited low levels of spontaneous activity that were inducible to higher levels by p-I:C; and 3) B10.S showed high endogenous levels of activity that were augmented to a still higher level by p-I:C treatment. In vitro incubation of spleen cells with partially purified IFN-β for up to 12 hr augmented NK activity of A.SW and B10.S but not of SJL mice. The relative levels of K cell-mediated ADCC in the three strains were similar to those of NK activity, including augmentability by p-I:C; however, the capacity to perform three additional cell-mediated immune functions, i.e., natural cytotoxicity against a fibrosarcoma target, adherent cell-mediated ADCC against antibody-coated chicken RBC, and alloimmune T cell-mediated cytotoxicity against appropriate targets, did not distinguish one strain from another. The low NK phenotype in SJL/JN remained distinctive throughout postnatal life, but there was a tendency for the highest levels of NK activity to occur in 4 to 8-wk-old mice.