H-2L: demonstration of four new allelic products and independence of H-2D and H-2L molecules.

The H-2L molecules were detected for the first time in the Dd region products using antisera against the public specificity H-2.28. This specificity was analyzed because its presence in K as well as in D region products and its apparent allelism with another public specificity, H-2.1, indicated that these two specificities may have a special position may have a special position in the H-2 system. This was corroborated by subsequent identification of H-2L molecules in Dq and Dk products using anti-H-2.28 AND ANTI-H-2.1 sera, respectively, while none of the other previously known public or private specificities was detected on H-2L molecules. We tested the products of four D region alleles which had not been analyzed previously. In each of them we identified two distinct types of molecules: H-2D, which reacts with sera agains the D region private specificity, and H-2L, which does not react with these sera, but which is detectable either by anti-H-2.28 sera (H-2Lb, H-2Lf, H-2LS) or by anti-H-2.1 sera (H-2Ldx). This increases the number of identified H-2L alleles to seven (five H-2.8+, two H-2.1+). No association between H-2D and H-2D and H-2L molecules on the cell surface was detected in capping experiments.