Antigen Presentation/immunology; Antigens, CD/immunology; Antigens, Differentiation, Myelomonocytic/immunology; Central Nervous System/immunology; Encephalitis/immunology; Macrophages/immunology; Receptors, Cell Surface/immunology; Aged; Antigen-Presenting Cells/immunology; Antigen-Presenting Cells/metabolism; Blood-Brain Barrier/cytology; Blood-Brain Barrier/immunology; Cell Adhesion Molecules/immunology; Cell Adhesion Molecules/metabolism; Central Nervous System/metabolism; Central Nervous System/physiopathology; Cerebral Arteries/cytology; Cerebral Arteries/immunology; Encephalitis/metabolism; Encephalitis/physiopathology; Female; Histocompatibility Antigens Class II/immunology; Histocompatibility Antigens Class II/metabolism; Humans; Inflammation Mediators/immunology; Inflammation Mediators/metabolism; Lectins, C-Type/immunology; Lectins, C-Type/metabolism; Lymphocyte Activation/immunology; Macrophages/metabolism; Male; Mannose Receptor; Mannose-Binding Lectins/immunology; Mannose-Binding Lectins/metabolism; Microcirculation/cytology; Microcirculation/immunology; Microglia/immunology; Microglia/metabolism; Middle Aged; Receptors, Cell Surface/metabolism; T-Lymphocytes/immunology