Generation of a monoclonal antibody that recognizes a polymorphic epitope of C57BL/6 Ly-49G2

To facilitate the study of natural killer (NK) cell functions, we have generated a panel of hybridomas that secrete antibodies recognizing B6 NK cell surface maskers. One of these hybridomas, Cwy-3, secretes a mouse IgG(1) specific for the B6 allele of Ly-49G2 (Ly-49G2(B6)). In addition, this monoclonal antibody (MAb) fails to stain A-LAKs derived from all other mouse strains tested. This suggests that Cwy-3 recognizes a polymorphic epitope of Ly-49G2(B6), More importantly, this MAb exhibits no cross-reactivity to other known B6 Ly-49 family members. Therefore, Cwy-3 is in sharp contrast to the two known anti-Ly-49G2 MAbs, which are reported to recognize a nonpolymorphic epitope of Ly-49G2, and react with other Ly-49 members. In this regard, Cwy-3 will offer significant advantages over the cross-reactive anti-Ly-49G2 MAbs in fully defining the specificity and function of the Ly-49G2(B6) NK cell receptor, With this novel Ly-49G2-specific MAb, we have isolated an EL-4 subline expressing a significant density of Ly-49G2 receptors.