The immunological response to transplanted sympathetic ganglia

Abstract

A cellular immune reaction has been described after transplantation of foreign sensory, but not sympathetic, ganglia to the anterior chamber of the eye. Since the catecholamine histochemical technique used in the sympathetic transplantation study was inadequate to identify immune cells, a study was undertaken to determine if foreign sympathetic ganglia are antigenic. Autologous, homologous, and heterologous (guinea pig) superior cervical sympathetic ganglia were transplanted to the anterior chamber of the eyes of rats and examined 2 and 5 weeks post-operatively. Neurons were present in 2- and 5-week autologous and homologous transplants, but none was present in heterologous ganglia. The autologous transplants exhibited no cellular immune reaction, the homologous ganglia were infiltrated by lymphocytes, and the heterologous tissue was infiltrated by neutrophilic leukocytes, and lymphocytes. The results of this study contrast with those of a previous study in which no cellular immune reaction was described and in which neurons in heterologous (mouse, human fetal) sympathetic ganglia transplants were reported to survive. I conclude that foreign sympathetic like foreign sensory transplanted ganglia are antigenic in that they evoke an immune response similar to that of other foreign tissues. Long-term studies are needed, however, to determine the fate of surviving neurons of homologous transplants.