Ly-6 region regulates expression of multiple allospecificities.

The relationship between two alloantigens on mouse lymphocytes, that is Ly-6.2 and H9/25, which have previously been shown to have identical strain distribution patterns, was further investigated. Analysis of 39 (AKR x CBA) x CBA backcross progeny showed no segregation between these two antigens, indicating a close genetic linkage between them. Serological analysis showed that Ly-6.2 and H9/25 are differentially expressed on T-cell hybrid lines. Furthermore, cross-absorption of anti-Ly-6.2 serum with two cell lines revealed a heterogeneity among Ly-6 specificities. Semipurified H9/25 antigen failed to block anti-Ly-6.2 serum while anti-Ly-6.2 serum did not significantly block monoclonal antibody H9/25. These results suggest the presence of multiple allospecificities encoded for by the Ly-6 region.