Immunological fate of Schwann cell-populated acellular basal lamina nerve allografts

Abstract

Acellular basal lamina allografts are known to exhibit reduced immunogenicity, but the extent of host axonal regeneration through such grafts is reduced in comparison to the cellular isografts. The present study was designed to determine both the ability of cultured Schwann cells to populate acellular allografts, and the effects of Schwann cells on immunogenicity and regenerative potential. Isogeneic and allogeneic Schwann cell-populated acellular allografts of 2.0 cm length were used to repair a surgically created gap in the host rat peroneal nerve. Transplanted nerves were analyzed at 1, 2, 4, and 8 weeks later to determine their fate and ability to support axonal regeneration. Acellular allografts cocultured with isogeneic Schwann cells survived and supported axonal regeneration through them. In contrast, acellular allografts cocultured with allogeneic Schwann cells underwent rejection and were unsuccessful. The results show that cultured Schwann cells continue to exhibit immunogenicity and are a critical factor in allograft survival. It is thus important to use host-matched (isogeneic or autologous) Schwann cells to populate acellular basal lamina grafts in order to enhance their axonal growth-supporting function.