Monoclonal Antibody 2B6-F2 Identifies a Subset of Murine Natural Killer Cells with Receptors for YAC-1 and WEHI-164 Targets

This study reports the generation of rat MoAb 2B6-F2 (IgG2a) that identifies a subpopulation of murine NK cells in the spleen, bone marrow, peripheral blood, lung, and peritoneal leukocytes. By flow cytometry, 2B6-F2 reacted with 10% of naive CBA (immunizing strain) spleen leukocytes of which 3% exhibited small lymphocyte morphology while 7% were large granular leukocytes. This pattern of binding was similarly obtained for BALB/c, C57BL/6, CE, and DBA/2 mice. 2B6-F2 and complement reduced splenic NK activity 40-57% in CBA, C57BL/6, BALB/c, CE, and DBA/2 strains. In CBA, C57BL/6, and CE mice ≤ 15% reduction in splenic NC activity was observed while DBA/2 and BALB/c mice displayed 55-73% reduction. Cellular competitive inhibition studies showed that 2B6-F2+ NK cells in BALB/c and DBA/2 mice bind and kill YAC-1 and WEHI-164 target cells via a receptor that recognizes a shared determinant on these targets. Western blot and radioimmunoprecipitation studies indicated that 2B6-F2 identifies a 14-kDa monomeric cell surface molecule.