Immune system associated antigens expressed by cells of the human central nervous system.

HLA-DR, HLA-DQ and HLA-DP are class II major histocompatibility complex (MHC) antigens necessary for T cell binding and antigen presentation. Interleukin-2 is a lymphokine used by the immune system to signal proliferation of cells in the immune response. Using unfixed tissue and free-floating immunohistochemistry, we show profuse immunoreactivity for these immune antigens in white and gray matter samples from normal and Alzheimer's (AD) disease patients. On morphologic grounds, immunoreactive cell types appear to include astrocytes, microglia, macrophages, and endothelial cells or pericytes.