Characterization of class II histocompatibility antigens in pigs

The D region of the SLA complex in the pig has been studied by immunochemical and sequential immunoprecipitation techniques as well as the redistribution of membranous antigens (capping). The molecules identified by the anti-la sera were solubilized by NP 40, purified on lectin and precipitated. Polyacrylamide gel electrophoresis under dissociating conditions shows that these molecules are made up of two chains whose molecular weights are 32 000 and 26 000 daltons respectively. Sequential immunoprecipitation and capping experiments indicate that two distinct types of la molecules exist. At least a part of the nylon-wood-adherent lymphocyte population expresses both types of molecules.