Cross-reactivity between organ extracts of gnotobiotic mice and enterobacterial common antigen.

Organs of gnotobiotic mice were assessed for an Ag (CRA) which cross-reacts with common enterobacterial Ag(CA). To this end, extracts of homogenates of spleens, livers, paired kidneys and colons were examined for their capacities to engender humoral and cellular events in rabbits. The immjnogenicity of CRA in the rabbit cannot be predicted on the basis of CA hemagglutinin-inhibition studies alone. According to this parameter, CRA was present in mouse spleens, livers and paired kidneys but absent in colons. However, the identical preparations, including colons, primed rabbits to engender specific CA hemaglutinins after a single administration of enterobacterial CA. Also, spleens of these same rabbits were colonized with rosette-forming cells against sheep red blood cells treated with various enterobacterial sources of CA. These findings may account, in part, for the apparent refractiveness or equivocal response mice have to administered CA and infectious challenge.