Central Nervous System Infections/immunology; Central Nervous System/immunology; Drosophila Proteins; Encephalitis/immunology; Immune System/immunology; Membrane Glycoproteins/immunology; Membrane Glycoproteins/metabolism; Neuroglia/immunology; Receptors, Cell Surface/immunology; Receptors, Cell Surface/metabolism; Aged; Aged, 80 and over; Astrocytes/immunology; Astrocytes/metabolism; Astrocytes/pathology; Cells, Cultured; Central Nervous System/metabolism; Central Nervous System/pathology; Central Nervous System Infections/metabolism; Central Nervous System Infections/pathology; Encephalitis/metabolism; Encephalitis/pathology; Female; Gene Expression Regulation/immunology; Humans; Immune System/metabolism; Immunohistochemistry; Male; Membrane Glycoproteins/genetics; Microglia/immunology; Microglia/metabolism; Middle Aged; Multiple Sclerosis/immunology; Multiple Sclerosis/metabolism; Multiple Sclerosis/pathology; Neuroglia/metabolism; Oligodendroglia/immunology; Oligodendroglia/metabolism; Oligodendroglia/pathology; RNA, Messenger/metabolism; Receptors, Cell Surface/genetics; Toll-Like Receptor 2; Toll-Like Receptor 3; Toll-Like Receptor 4; Toll-Like Receptors