title: Role of Ly-6 in lymphocyte activation. I. Characterization of a monoclonal antibody to a nonpolymorphic Ly-6 specificity.
abstract: In studies with alloantisera and monoclonal antibodies (mAb) a number of antigenic determinants have been defined that are the products of the Ly-6 locus on murine chromosome 2 and that are expressed primarily on B and T lymphoid cells. It remains controversial whether these antigenic determinants are encoded by a single gene or a multigene complex. We have characterized a new rat mAb, D7, which recognizes a cell surface antigen whose expression on nonactivated peripheral lymphocytes varies from strain to strain. The phenotype of the staining profile, i.e., high or low percentage of D7-positive cells, mapped to the Ly-6 locus as assayed by strain distribution studies, RI lines, and Ly-6 congenic strains. The binding of D7 to Ly-6.1-positive strains could be inhibited by mAb directed to the Ly-6E.1 specificity, whereas D7 could inhibit the binding of mAb specific for Ly-6A.2 to cells from Ly-6.2-positive strains. Coprecipitation studies followed by Western blot analysis confirmed that D7 reacts with both Ly-6E.1- and Ly-6A.2-bearing molecules. The most likely explanation for these findings is that Ly-6A.2 and Ly-6E.1 represent allelic specificities. Further dissection of the complexity of the Ly-6 antigen system and determination of its possible functional importance in lymphocyte activation should be greatly facilitated by the availability of xenogeneic mAb that recognize framework determinants on multiple Ly-6 products.
mesh_terms: D000483:Alleles; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000950:Antigens, Ly / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D000939:Epitopes; D005434:Flow Cytometry; D008213:Lymphocyte Activation; D051379:Mice; D008970:Molecular Weight; D011110:Polymorphism, Genetic; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D000939:Epitopes