Reactions and Crossreactions of a Rabbit Anti‐H2 Antigen Serum

Abstract

A rabbit antiserum raised against highly purified, papain-solubilized H-2d antigens contained 2 sets of non-crossreacting antibodies directed against each 1 of the 2 H-2 antigen subunits. The antiserum recognized only 12,000 and 47,000 dalton polypeptide chains when splenocyte membrane glycoproteins were analyzed. Among the molecules precipitated with the rabbit antiserum all H-2K and D antigens were present. In addition to regular H-2K and D antigens, minor amounts of material with the typical H-2 antigen subunit structure, but lacking alloantigenic determinants, were precipitated by the antiserum. These non-H-2 antigens were produced in relatively greater amounts by T[thymus-derived]-cells than by B[bone marrow-derived]-cells. Both sets of antibodies in the rabbit antiserum reacted with the TL [thymus-leukemia] antigens demonstrating that there is an immunological crossreactivity between the classical alloantigenic H-2 antigen chain and the alloantigenic TL antigen chain. The [mouse embryo carcinoma] F9 cell line, believed to represent cells at the morula stage, displays H-2 antigen-like structures as revealed by the rabbit antiserum.