Chapter 25 Class I and II MHC expression and its implications for regeneration in the nervous system

Abstract

Publisher Summary This chapter reviews neural major histocompatibility complex (MHC) expression under a variety of developmental, pathological, and experimental conditions. Ways in which the predominant patterns of neural MHC expression are most likely to influence neural regeneration are discussed. Neural tissue displays a consistent pattern of MHC expression under a variety of conditions. MHC + cells, including endothelial cells, mononuclear phagocytes, microglia and ependymal cells, can be in direct contact with neural cells. Neural cells themselves including neurons, astrocytes and oligodendrocytes, do not show detectable MHC expression. While alternative techniques may yet reveal neural MHC expression or function, the predominant pattern itself offers multiple opportunities for MHC-mediated effects. Evidence for a nonimmunologic role for MHC proteins in neural tissues was sought, but not found. This implies that modulating MHC expression need not itself interfere with neural regeneration. A more subtle question concerns the effects of modulating cytokine secretion. Neural cells and leukocytes may be affected by the same cytokines, and individual cytokines may enhance rather than inhibit regeneration.