IgA-containing cells in the ruminant intestine following intraperitoneal and local immunization

Experiments are described which demonstrate that a single intraperitoneal (i.p.) injection of antigen in Freund's complete adjuvant results in the appearance of IgA-specific antibody-containing cells (ACC) in the intestinal lamina propria of sheep and that these cells reach the intestine via the intestinal lymph and blood circulation. Following intraintestinal administration of antigen to sheep immunized i.p. 2 weeks previously, an enhanced ACC response occurs in the intestine but cannulation and drainage of the intestinal duct does not interfere with this enhancement. Evidence is presented which suggests that the enhanced ACC response may be accounted for by antigen-induced local proliferation of ACC in the lamina propria of the intestine.