Relationship Between Precipitative and Protective Antibodies of Type III Shigella paradysenteriae (Flexner) Immune Serum

Abstract

Summary1. Antisera prepared by prolonged immunization of rabbits with Type III Shigella paradysenteriae (Flexner) contain mouse protective antibodies which can be removed by absorption with the chemically purified type specific antigen. Absorption of the serum with the polysaccharide portion of the antigenic complex removes approximately 80-90% of the precipitating and protective antibodies.2. Most, if not all, of the protective antibodies present in Flexner Type III antiserum are directed against the homologous specific antigen. Any protective antibodies reactive with other constituents of the bacterial cell appear to have little or no significance in the immune response. The polysaccharide hapten is the component of the antigenic complex most important in orienting the protective and precipitative antibodies.†