Murine NK cell heterogeneity: subpopulations of C57BL/6 splenic NK cells detected by NK-1.1 and NK-2.1 antisera.

NK-1.1 antiserum - (BALB/c X C3H)F1 anti-CE - and NK-2.1 antiserum - NZB anti-BALB/c - detect genetically distinct alloantigens on C57BL/6 natural killer (NK) cells. We have analyzed whether these two alloantigens are associated with functional subsets of NK cells. For this study, nylon wool nonadherent C57BL/6 spleen cells (SC) were treated with complement (C) and NK-1.1 or NK-2.1 antisera and then tested for NK activity against a panel of tumor targets in 6- and 19-hour 51Cr release assays. The NK activity against the prototype NK target YAC-1 was reduced equally by both antisera. Similar reductions by both antisera were also observed when SC were tested against another murine lymphoma target, L5178c127v, against the C57BL/6 melanoma B16, and against the human liver cell line Chang. In contrast, NK activity to the lymphoma FBL-3 and the human erythroleukemia K562 was significantly reduced in SC treated with NK-2.1 antiserum and C, whereas SC treated with NK-1.1 antiserum and C showed either less reduction or no reduction in activity against these two cell lines. With two other targets, E male G2 and RBL-5, neither serum produced significant depletion of activity, Analysis of SC indirectly labeled with either NK-1.1 or NK-2.1 antiserum and fluorescein-labeled goat anti-mouse Ig, however, did not detect significant differences between NK-1+ and NK-2+ cell populations.