Immunochemical studies on pneumococcal type 37 capsular polysaccharide

Pneumococcal type 37 capsular polysaccharide was obtained free of contaminants by affinity chromatography on Con-A, wheat germ agglutinin, Maclura pomifera lectin and HOPC-8 mouse myeloma protein affinity columns. The immunochemical reactivity of native and periodate oxidized borohydride reduced type 37 polysaccharide antigen with polyclonal rabbit and monoclonal mouse anti-Pn37 hybridoma antibodies was studied by quantitative precipitation. Quantitative hapten inhibition studies, employing the isomeric series of alpha- and beta-(1----2), (1----3), (1----4) and (1----6)-linked glucobioses as competitive inhibitors of antibody precipitation establish a specificity for anti-Pn37 antibody directed at least in part, against the Glc beta(1----2) Glc (sophorosyl) unit. A high mol. wt, D-glucose containing polysaccharide antigen, cross-reactive with rabbit anti-Pn37 is reported which was found to occur in the culture medium of 7 of 19 strains of Actinomyces examined.