Contributions to the elucidation of S XIV pneumococcal polysaccharide structure

Rabbits were immunized with a hemocyanin (Hcy)-p-amino phenyl beta lactoside (PAFBLO) conjugate and the gamma globulin fraction from immune sera was purified. Antibodies were demonstrated by means of the quantitative precipitin reaction using an egg albumin (EA)-PAFBLO conjugate as antigen. PAFBLO, D-lactose, D-galactose, cellobiose and D-galacturonic acid were used as inhibitors of the precipitin reaction and their relative affinity constants were calculated. The best inhibitors were the homologous hapten, D-lactose and D-galactose. Anti PAFBLO antibodies precipitated with types 6, 14 and 18 pneumococcal polysaccharides (SVI, SXIV and SXVIII) probably due to the presence of either D-lactose or D-galactose in similar linkage as in PAFBLO in these polymers. Antibodies also reacted with human red blood cells type B.