Transplantation immunobiology in relation to neural grafting: lessons learned from immunologic privilege in the eye.

The principles of transplantation immunobiology are described and discussed in terms of their applicability to neural grafting, a newly emerging field dedicated to the ultimate goal of reconstituting central nervous system deficits with normally functioning tissue replacements. Unique anatomic and physiologic features of the eye, which are responsible for the phenomenon of immunologic privilege, are compared with the brain and considered in terms of their relationship to the principles of transplantation. The existence of immune privilege in the brain and the newly acquired understanding of immunologic privilege in the eye may offer strategies by which neural grafters can achieve significantly greater graft acceptance.