title: Temperature-sensitive alteration in fusion activity of subacute sclerosing panencephalitis virus during serial passages in vitro and expression of hemagglutinin on the infected cells.
abstract: The Biken strain of subacute sclerosing panencephalitis (SSPE) virus, a maturation-defective variant of measles virus, was serially passed in human embryonic lung (HEL) cells at 37 C. The strain formed syncytial giant cells (GC) at both 37 C and 39 C, but the surface of infected cells did not show hemadsorption at early passages of the strain. However, GC-forming activity of the strain diminished at 39 C after 25 passages or more and hemadsorption on the infected cells became positive at both 37 C and 39 C after 40 passages or more of the strain. Hardly any infectious cell-free virus was detected in the culture fluid even after hemadsorption became positive. Possible mechanisms for the defect of SSPE virus were discussed.
mesh_terms: D002459:Cell Fusion; D002460:Cell Line; D003588:Cytopathogenic Effect, Viral; D006382:Hemadsorption; D006389:Hemagglutinins, Viral; D006801:Humans; D013190:SSPE Virus / Q000502:physiology*; D013696:Temperature
chemical_list: D006389:Hemagglutinins, Viral