Cell-associated subacute sclerosing panencephalitis agent studied in organotypic central nervous system cultures: viral rescue attempts and morphology.

Organotypic cultures of hamster cerebellum were exposed to the IP-3-Ca cell line , which contains a cell-associated subacute sclerosing panencephalitis agent. Central nervous system (CNS) cultures were examined by light and electron microscopy as well as standard virological techniques from 3 to 46 days postinfection. The results indicate that although viral nucleocapsid material was transferred to elements of the CNS, cell-free virus could not be detected by virological techniques and by electron microscopy, and budding viral particles were not observed. Attempts to recover cell-free virus from hamster CNS tissue exposed to IP-3-Ca cells were generally negative. However, 2% of the cultures yielded low levels of infectious virus. IP-3-Ca cells were able to transfer the cell-associated viral material to all cell types found in the CNS cultures and were capable of inducing polykaryocytes in the CNS cultures. The role of cell-associated virus-like agents in subacute sclerosing panencephalitis and other chronic CNS infections is discussed.