Immunologic mimicry between mouse tissue and enterobacterial common antigen

Organs of Swiss white albino and C57BL/6Ha mice were assessed for an antigen (CRA) which cross-reacts with common enterobacterial antigen (CA). To this end, supernatant fluids (HKS) and ethanol-soluble fractions (ES) of heated homogenates of spleens, kidneys, and livers were examined for their capacities to react with CA hemagglutinins and to engender humoral and cellular events in the rabbit. The immunogenicity of CRA in the rabbit can not be predicted on the basis of CA hemagglutinin neutralization studies alone; although CRA was identified in the liver extracts of both mouse strains, according to this parameter, only the liver fraction of Swiss white albino mice elicited significant numbers of rosette-forming cells (RFC) in the spleens of rabbits. Also, kidney fractions, which primed the rabbits for booster with CA, were less effective in stimulating RFC in the spleens failed to inhibit CA hemagglutination and did not prime rabbits for a CA hemagglutinin response, these same preparations clearly evoked RFC in rabbit spleens. Thus, the antigenicity and immunogenicity of CRA in target organs of mice reflect the mouse strain, extraction procedure, and testing method employed.