ABSTRACT
The storage proteins of several cereals, including wheat gliadins, are complex antigens with some lectinlike properties and might, therefore, be predicted to sensitize rather than tolerize when fed even to healthy individuals. When mice from the gluten-free diet colony were given a single feed of gliadin, there was a dose-dependent reduction in the cellular and humoral immune responses to subsequent parenteral immunization with gliadin in CFA. The results of clinical, pathological observations of patients undergoing gluten challenge, gluten loading and of our mouse experiments suggest that induction of a state of systemic delayed-type hypersensitivity to gliadin is sufficient for the full expression of intestinal cell-mediated immunity to gluten, with enteropathy. When the type of immune response has been induced, ingress of antigen after a further feed may result in a local immune reaction with tissue damage—hypersensitivity. The experiments presented demonstrate that in respect to immunogenicity when systemically administered and tolerogenicity when fed, wheat gliadin is similar to many other protein antigens.
