Immune response induction in the central nervous system

The primary function of the immune response is protection of the host against infection with pathogens, including viruses. Since viruses can infect any tissue of the body, including the central nervous system (CNS), it is logical that cells of the immune system should equally have access to all tissues. Nevertheless, the brain and spinal cord are noted for their lack of immune presence. Relative to other organ systems, the CNS appears immunologically privileged. Furthermore, when immune responses do occur in the CNS, they are frequently associated with deleterious effects such as inflammatory and/or demyelinating pathology. This article will review the molecular and cellular dynamics of immune responses in the CNS, with particular emphasis on autoimmune inflammation, as has been studied in the authors' laboratory.