ABSTRACT
This chapter focuses on the spectrum of interactions occurring between the mucosal immune system and the antigens in the mucosal environment. An important and somewhat surprising feature of the immune unresponsiveness that follows oral antigen administration is that it is to some extent immunoglobulin (Ig) class specific. Since, as alluded to above, systemic lymphoid tissue may have a greater tendency to mount helper T-cell responses than mucosal lymphoid tissues, IgA-mediated antigen clearance becomes another way of shunting responses to mucosal antigens into the controlled regulatory environment of the Peyer’s patch. In conclusion, gluten-sensitive enteropathy and IgA deficiency represent related abnormalities because they are caused by defects in different but associated aspects of mucosal function, one concerning regulation of antigen-specific responses and another concerning regulation of Ig class-specific responses. Evidence that supports the viewpoint has been gathered in numerous studies of mouse models of autoimmune disease.
