Phagocytic, Serological, and Protective Properties of Streptococcal Group A Carbohydrate Antibodies
To determine whether antibodies other than the type specific protein were phagocytic and protective, we embarked on a study of group A carbohydrate (GRA-CHO) antibodies in human sera. Using a modified in vitro phagocytic assay, we determined that carbohydrate antibodies were phagocytic for several different type specific GRA streptococcal strains. The opsonic activity could be abolished by absorption with sepharose coupled N-acetyl glucosamine beads (1). Animals immunized with GRA coupled to tetanus toxoid (TT), resulted in sera with high titers to GRA-CHO. These rabbit sera were also phagocytic for multiple type specific GRA strains. Positive passive protection tests against two different M type strains were seen with these rabbit anti-sera in an in vivo mouse model challenge assay.
KeywordsProtective Property Tetanus Toxoid Rabbit Seron Opsonic Activity ELISA Titer
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