A 65-KDA TRYPSIN-SENSIBLE MEMBRANE CELL PROTEIN AS A POSSIBLE RECEPTOR FOR DENGUE VIRUS IN CULTURED NEUROBLASTOMA-CELLS

Dengue virus infects primary neurons in mouse experimental model and t issue culture cells of the central nervous system (CNS). In the presen t work, a mouse neuroblastoma cell line (N1E-115) and a human neurobla stoma cell line (SK-N-SH), susceptible to dengue virus infection were used to study the presence of cell membrane receptor for dengue-2. By day 5 postinfection (pi), viral antigen was detected by immunofluoresc ence in the cytoplasm and surrounding the nucleus of N1E-115 cells, wh ile on day 7 pi, it was also present along neural extensions. Infectio n of N1E-115 cells was diminished with trypsin treatment but not with neuraminidase or endoglycosidase H. Partially purified cell membrane p roteins from neuroblastoma cells were analyzed by the Virus Overlay Pr otein Blot Assay (VOPBA), and a single band migrating at 65 kDa was de tected in mouse and human neuroblastoma cells but not in C6, a non-sus ceptible rat glial cell line which was included as a negative control. The 65 kDa protein was eliminated only when nitrocellulose membranes were treated with trypsin. Analysis of neuronal cell infection by deng ue virus provides a useful tool to understand the nature of cellular r eceptors and mechanisms involved in the infection of the nervous syste m by dengue viruses.