Molecular heterogeneity of D-end products detected by anti-H-2.28 sera. III. Reactivity of certain anti-H-2.28 alloantisera with Qa-2 antigen.

In capping experiments with peripheral T lymphocytes, two anti-H-2.28 sera (AKR anti-AKR.L, anti-Kb, and C3H anti-C3H.B10, k anti-b) that do not contain any Qa-2-specific antibodies are able to redistribute not only the H-2.28-positive H-2 molecules, but also Qa-2 molecules. This is due to the capacity of these sera to react with Qa-2 molecules because on cells where all known molecules of the H-2d haplotype were capped (K1d, K2d, Dd, Md, Ld, L2d), both antisera still reacted when the cells came from a Qa-2 positive Dd strain (B10.A) but not when the cells were of Qa-2 negative strain (BALB/cByA). The reaction with Ia and non-H-2 antigens was excluded in these experiments. These data show that Qa-2 and H-2 antigens share some specificities of the H-2.28 family. Other anti-private and anti-public anti-H-2 sera failed to react with the Qa-2 molecules.