The influence of Peyer's patches on the organ-specific distribution of IgA plasma cells.

After the surgical removal of Peyer's patches (PP) in rats, the IgA-containing cells in the thoracic duct, mesenteric lymph nodes and lamina propria of the small intestine are decreased, as shown by immunohistology. The analysis of the immunoglobulin secretion in agar of single-cell suspensions confirmed these results. Using lipopolysaccharide (LPS) 055B5 as antigen, it could be demonstrated that this reduction may be the result of an inadequate presentation of antigen and/or impaired migration of locally primed antigen (AG)-specific cells. The oral application of heat-inactivated Escherichia coli 055B5 to PP-deprived rats resulted almost exclusively in anti-LPS-secreting cells in the mesenteric lymph nodes and spleen, whereas in control animals these cells were distributed along the intestine. Therefore, in rats PP have an important function in the regulation of the intestinal immune responses.