Expression of P2 protein by Lewis rat Schwann cells in vitro

P2 protein is found in Schwann cells of the peripheral nervous system (PNS) in vivo and is a component of the myelin sheath. In previous studies by the authors, there have been indications that in vitro, Schwann cells can process and present endogenous P2 peptides to P2-specific T-cells capable of effecting experimental allergic neuritis (EAN) in the Lewis strain of rat. EAN is an animal model of Guillain-Barré syndrome, a human autoimmune disease of the PNS. However, previous studies have shown no evidence of expression of P2 protein by Schwann cells. Therefore, the aim of this study was to determine whether P2 is present in freshly dissociated Lewis rat Schwann cells and thus an endogenous source of peptides. In contrast to previous studies, we found P2 to be present in detectable levels within the cytoplasm of most Schwann cells up to 1 week in vitro, with the level of expression varying from cell to cell.