Comparative Study of Rabbit Hemolysins to Various Antigens I. Hemolysins to Beef Red Cells

Abstract

In early anti-beef-cell serums, hemolysin activity was mainly associated with a fast-sedimenting fraction (S20=18 S) which migrated electrophoretically in the gamma-1-globulins. Its mobility was about the same as that of the gamma 1-sheep isophile hemolysin, but less than that of the gamma 1 Forssman hemolysin. In late serums, a second hemolysin was found in the gamma 2 globulins which sedimented with a fraction having an S20 of about 6 S, and which comprised about 50 to 75% of the total hemolysin activity. Absorption tests indicated that anti-beef-cell serums contained no anti-Forssman activity. Absorption of anti-beef-cell hemolysins with sheep red cells removed about 50% of the activity against beef red cells, whereas absorption with the heated stromata of beef red cells had no effect. Beef red cells therefore contain at least 2 major antigenic groups that are heat labile. Moreover each of these groups stimulated the production of at least 2 physically distinct hemolysins whose relative mobility, however, was the same in each case. Neither of these 2 groups appeared to be serologically related to the isophile antigen of sheep red cells. To account for the activity of beef-cell hemolysins against sheep red cells, it has been postulated that sheep cells contain an haptenic group serologically related to one of the 2 antigenic groups of the beef red cell. The finding of 2 antibodies to each of these groups is similar to that found with the Forssman and isophile antigens of sheep red cells and supports the hypothesis that one antigenic group may stimulate the production of more than one physical type of antibody.