Immune Agglutination and Lysis of Antigen Modified Erythrocytes from Various Animal Species.

Abstract
Erythrocytes from man, sheep, and goat, modified by O antigens from Enterobacteriaceae and heterogenetic (staphylococcal) antigen, are readily agglutinated by the corresponding antibodies, and treatment of these erythrocytes with proteolytic enzymes only slightly enhances the agglutination reaction. In contrast, similarly treated erythrocytes from alligator and ox are not agglutinated or agglutinated only in low titer; enzyme treatment markedly enhances the agglutination reaction. Erythrocytes from all these animal species modified by Vi antigen are readily agglutinated by Vi antiserum in high titer. Poorly agglutinable ox erythrocytes modified by O antigen are lysed in the presence of O antibody and guinea pig complement. Vi antigen present together with O antigen on latex particles and erythrocytes significantly inhibits agglutination by O antibodies. Erythrocytes modified by both O and Vi antigens effectively remove O antibodies.