Restoration of Antibody Response to Sheep Erythrocytes in Thymectomized Mice Following Grafting of Rabbit Appendix 1

Abstract

Summary

Since the isophile hemolysin response to sheep red blood cells (SRBC) is depressed in thymectomized mice, the effect on the response was studied by implanting the appendix of neonatal, New Zealand white rabbits into young, neonatally thymectomized CBA mice prior to the injection of SRBC. The neonatal appendix, containing only epithelial-reticular elements and no lymphoid cells, restored 61% of the reduction of the peak hemolysin titer caused by thymectomy, whereas the rabbit thymus was ineffective under similar conditions. The appendix, but not the thymus, also led to a repopulation of the periarteriolar region of the white pulp of the spleen of the experimental mice. These data indicate that the neonatal rabbit appendix is capable of partially restoring he-molysin-forming capacity across xenogeneic barriers, possibly by the elaboration of a humoral factor, and support the suggestion that the appendix may represent, in part, the mammalian immunologic equivalent of the avian bursa of Fabricius.