Inviting applications to promote research into the role of microglia in the initiation and expansion of autoimmune processes of the central nervous system (CNS) and the resulting injury to CNS components. Microglia become reservoirs of infectious agents including viruses, fungi, treponema and prions. Under certain conditions, they assume the phenotypes and functions of macrophages. They may become activated and then be able to serve in antigen presentation. The contributions of these cells not only to infections of the CNS, but also to autoimmunity, are beginning to be appreciated. The intent of this PA is to intensify interest and investigator-initiated research to attract new investigators to this field and to mobilize interdisciplinary approaches.