Major histocompatibility complex molecules on glial cells

While glial cells of the central nervous system do not constitutively express class I or II major histocompatibility complex (MHC) molecules, astrocytes and microglial cells can be induced by a variety of factors to express these antigens. Oligodendrocytes have inducible class I but not class II elements. There are considerable differences in regulation of MHC antigen expression between glial cells from rodent and human brains, both in situ and in vitro. The consequence of glial cell MHC expression for immune interactions in the CNS is discussed in the context of glial cell antigen presentation capacity and neural cell susceptibility to cell-mediated immune effector mechanisms.