Factors Affecting the Adsorption of Esterified Streptococcal Group A and E Cell Wall Polysaccharide Antigens to Red Blood Cells and Their Effect on Antibody Measurement

摘要

The streptococcal group A and E cell wall polysaccharide (PS) antigens were each esterified with one of 4 fatty acid chlorides. The terminal hexose unit of each polysaccharide was not extensively esterified. The esters were used to sensitize red blood cells (RBC) and the cells were shown to lyse in the presence of guinea pig complement and group specific antibodies. Sera from children hospitalized with clinical streptococcal respiratory disease, and rabbit anti-A and anti-E sera, were shown to possess hemolytic titers which were significantly greater than the hemagglutination titers. Both IgM and IgG group A antibodies participated in the precipitin, agglutination and hemolytic reactions. The lipids of the RBC membrane were necessary for adsorption of the ester to the cell; the addition of cations was not required. The importance of hydrogen and hydrophobic bonds in the complex formation between ester and formalinized RBC were shown by urea and detergent treatment of the sensitized cells. When the RBC were sensitized consecutively with 3H-labeled group A and group E esters, the results demonstrated that no inhibition of the uptake of the second ester had taken place. The treatment of RBC with trypsin or neuraminidase prior to sensitization did not result in any significant change in the uptake of radioactive ester or agglutination titer. Treatment of the esters with N-acetylglucosaminidase or β-glucosidase showed that the terminal hexose unit was not extensively esterified