Antigenic cross-reaction between mouse intestine and a member of the autochthonous microflora

Antigenic cross-reaction has been demonstrated between homogenates of intestine taken from fetal mice and suspensions of a Bacteriodes species isolated from the large intestines of normal adult mice. This observation provides an explanation for the lack of immunological response observed in mice after antigenic stimulation with this member of the normal autochthonous intestinal flora of these animals.