ULTRASTRUCTURAL AND IMMUNOHISTOLOGICAL EVIDENCE FOR DENDRITIC-LIKE CELLS WITHIN HUMAN CHOROID-PLEXUS EPITHELIUM

ULTRASONIC examination of human choroid plexus (CP) disclosed the pres ence of a possibly new type of CP cells displaying many of the feature s of dendritic cells and apparently expressing HLA Class II antigens. These cells bear long processes, devoid of tight junctions, inserted b etween CP epithelial cells, and have close contacts with CP basement m embrane, They could, therefore, play a key role in immunosurveillance in the central nervous system.