title: Further biological properties of the human syncytial virus.
abstract: Some biological properties of the human syncytial virus have been examined. A 13-day plaque assay in whole human embryo fibroblasts (HEF) has been developed using a liquid (growth medium) overlay. The plaques were 0.7-2 mm in diameter and often showed a clear central zone with irregular edges. Pretreatment of HEF monolayers with the polycation DEAE-dextran for either 30 min or 1 h was found to enhance plaque formation by a factor of from 2- to 7-fold. The plaque assay procedure required cell cultures undergoing active cell division. Adsorption kinetics and growth cycle studies in HEF indicated a relatively long adsorption period (3 h) and a relatively prolonged latent period of 24 h. Even under optimal conditions, virus yields were low and did not exceed 1 PFU per infected cell. Like other animal syncytium-forming 'foamy' viruses, the human virus induced both intranuclear and cytoplasmic antigens detectable by immmunofluorescence and was also markedly labile to freezing and thawing.
mesh_terms: D000327:Adsorption; D000956:Antigens, Viral / Q000032:analysis; D002460:Cell Line; D003637:DEAE-Dextran / Q000494:pharmacology; D005347:Fibroblasts; D005615:Freezing; D006801:Humans; D012328:RNA Viruses / Q000254:growth & development*; D016092:Spumavirus / Q000187:drug effects / Q000254:growth & development* / Q000276:immunology; D013696:Temperature; D010948:Viral Plaque Assay; D014779:Virus Replication
chemical_list: D000956:Antigens, Viral; D003637:DEAE-Dextran