Migration of Individual Lymphocytes into Peyer’s Patches In Vivo

Abstract

Peyer’s patches are macroscopically recognizable aggregates of lymphoid tissue within the intestinal mucosa which function as major sites of antigen sampling, immune response generation and lymphocyte traffic. Morphologically, these patches contain nodules comprised primarily of B cells and inter-nodular corridors where T cells predominate. Peyer’s patches collect T and B lymphocytes continuously and in large numbers from the blood stream. It is well recognized that the collection of blood-borne lymphocytes in Peyer’s patches occurs, as it does in lymph nodes, at the level of the post-capillary venules. The anatomy of these vessels appears to be highly specialized to perform this function (1,2), and there is now strong evidence that the interaction of lymphocytes with the specialized high endothelium of these vessels is mediated by specific surface determinants of both the lymphocyte and the endothelial cells (3–9).