The brain was considered an immunologically privileged organ. This view is undermined, inter alia, discovery that occur within the CNS antigen presentation. It is not exactly known which of endogenous brain cells are responsible for this process. The experiments focus on demonstrating the expression of MHCII and costimulatory molecules on the surface of these cells and their ability to activate T cells in the test environment subject discusses the role of glial cells - astrocytes, microglia, and endothelial cells and perivascular macrophages - in the presentation of antigen in the brain.