Interferon-gamma inhibition suppresses experimental allergic neuritis: modulation of major histocompatibility complex expression of Schwann cells in vitro.

This study examines the modulation of major histocompatibility complex (MHC) expression on Lewis rat Schwann cells (Scs) cultured in the presence of dorsal root ganglion neurons (DRG). MHC class I and II molecules were induced on Scs using recombinant murine interferon-gamma (IFN-gamma), lymph node cells (LNC), removed at day 9 from Lewis rats with experimental allergic neuritis (EAN) and syngeneic T-cell line cells responsive to P2 basic protein. EAN LNC induced MHC class I on Scs but only IFN-gamma or P2-responsive T-cells induced MHC class II. Control LNC from animals injected with Freund's adjuvant alone or naive spleen cells did not induce MHC class II. P2 T-cells clustered in aggregates to the Scs. Similar studies were performed with inhibitors of IFN-gamma; hydrocortisone, cyclosporin A, dibutyryl cyclic AMP, methyl-xanthine and prostaglandin E2. Each agent produced a dose-dependent inhibition of MHC expression and prevented clustering of P2-responsive T-cells to Scs.