Graft-versus-host reaction induced by Peyer's patches

Parental Peyer's patches were implanted into the anterior hepatic lobe of F1 hybrid rats. Using conventional histological techniques, phenomena typical of a graft-versus-host reaction were observed, such as paravascular lymphoid infiltration in the liver, cellular depletion of the thymus-dependent areas of spleen, and diffuse reticuloendothelial cell proliferation in various lymphoid tissues. Based on these findings and other observations it is concluded that a thymus-dependent cell population is present in the Peyer's patches.