In vitro and in vivo behaviour of NDF-expanded monkey Schwann cells

Schwann cells, the myelin-forming cells of the peripheral nervous system may play a major role in the regeneration and remyelination not only of the peripheral but also of the central nervous system. The discovery of the mitogenicity of human recombinant forms of neuregulins (glial growth factors) on primate Schwann cells allows us to envisage a considerable expansion of these cells in culture with a view to autologous transplantation in the central nervous system. To assay this possibility, we used human recombinant neu-differentiation factor beta (NDFbeta) to expand monkey Schwann cells derived from perinatal and adult nerve biopsies. We report that NDFbeta containing the epidermal growth factor (EGF)-like domain (residues 177-228) is a potent mitogen for monkey Schwann cells but is more effective on perinatal than adult Schwann cells. Moreover, continuous treatment with NDFbeta, does not seem to prevent Schwann cells differentiation into myelin-forming cells after their transplantation into the demyelinated mouse spinal cord. These observations, in addition to the close similarities of in vitro behaviour which exist between human and monkey Schwann cells, indicate that monkey Schwann cells could be an ideal tool to study the potential and limits of autologous transplantation in a non-human primate model of central nervous system demyelination.