Survival of neurons in homografts of ganglia in adult rats neonatally treated with bone marrow or lymph node cells.

Abstract

AbstractBecause of a major (Ag‐B) histoincompatibility, organs transplanted from Lewis (LE) to Brown Norway (BN) rats are acutely rejected. This immunological rejection can be prevented by inoculating BN rats at birth with (BN × LE)F‐1 hybrid cells. However, the source of these cells is important since only those derived from the bone marrow are effective in inducing tolerance of LE skin grafts whereas both marrow derived cells as well as those originating from the lymph nodes can induce tolerance of LE hearts. The present study was undertaken to compare the efficacy of cells derived from the bone marrow and the lymph nodes of (BN × LE)F‐1 rats to induce unresponsiveness to LE neurons in BN recipients. In untreated rats, all neurons in sensory (vagal nodose) and sympathetic (superior cervical) ganglia transplanted from LE rats to the anterior chamber of the eye or implanted into the sternomastoid muscle of BN recipients were rejected within 35 days. However, when neonatal BN rats were inoculated with adult (BN × LE)F‐1 hybrid bone marrow or lymph node cells and challenged as adults with LE ganglia grafts many neurons survived beyond 100 days. This result demonstrates that tolerance of Ag‐B incompatible neurons can be achieved with either bone marrow or lymph node cells. Moreover, since tolerance can be produced in rats exhibiting major or minor histoincompatibilities, this method of immunosuppression offers one way of preventing neuronal rejection which occurs acutely in Ag‐B incompatible and chronically in Ag‐B compatible ganglia homografts.