Factors affecting expression of antibody responses in the intestine

The aim of the work presented in this thesis was to examine the role of T helper cells (Th) and other factors affecting the expression of antibody responses in the intestinal niucosa. The experiments described in this thesis demonstrate that in rats, a population of antigen specific Th cells appears in the gut mucosal tissues and PP are an enriched source of these cells if appropriately immunized. These cells have the capacity to migrate via the TDL and in addition to their role in induction sites may also have a role in effector sites such as the gut LP and possibly other mucosal sites such as the lung. This work provides further evidence for the hypothesis that IgA responses occurring after immunization of the intestine are as much a reflection of the activities and location of regulatory T cells as of the B-cell precursors of ACC. Immunization of PP by routes other than the natural route through the gut epithelium stimulates a vigorous response to antigens which elicit tolerance if given by the oral route.