Antigen presentation in the peripheral nervous system: Schwann cells present endogenous myelin autoantigens to lymphocytes

Abstract

Schwann cells (SC) isolated from neonatal rat sciatic nerves are shown to immunogenically present foreign and exogenous autoantigen to antigen‐specific syngeneic T line cells in vitro. The antigen‐presenting SC express Ia antigens on their membranes upon treatment with interferon gamma and contact with syngeneic T line cells. Monoclonal antibodies against Ia block specific antigen presentation, but not polyclonal mitogenic T cell activation. The antigen‐presenting SC bind antibodies specific for astrocytic glial fibrillary acidic protein and may thus be related to the nonmyelinating glia cells of the peripheral nerve. Furthermore, SC isolated from 6‐day‐old rats activate rat myelin basic protein (MBP)‐specific syngeneic T line cells in the absence of exogenous MBP. In contrast, they activate purified protein derivative of tuberculin (PPD)‐specific T cells only in the presence of PPD. Since the MBP‐specific T line cells are not activated by syngeneic professional antigen‐presenting cells in the absence of MBP, endogenous MBP produced in the 6‐day‐old sciatic nerves appears to be presented by autochthonous SC to the autoreactive T cells. The Clinical Research Unit for MS is supported by funds of the Hermann‐and‐Lilly‐Schilling Foundation.