title: The production of a temperature-sensitive persistent measles virus infection.
abstract: A persistent infection of measles virus was established in HEp2 cells. All cells contained virus antigen when tested by specific immunofluorescence and approx. 50% were positive by haemadsorption. Infectious virus released into the supernatant medium was usually equivalent to no more than 0-001 p.f.u./cell, but between 10 and 40% of the infected cells produced plaques when plated on Vero cells. Passage of persistently infected cultures in the presence of measles antibody had no effect on the proportion of antigen-positive cells. Virus obtained from the supernatant medium of persistently infected cultures was temperature sensitive at 39-5 degrees C when tested on Vero cells whereas the original non-persistent virus produced infections on Vero cells at 39-8 degrees C. On passage of the persistently infected culture at 39-5 degrees C most of the surface antigens disappeared within 24 h whereas the intracellular virus antigens had not totally disappeared until the 5th passage.
mesh_terms: D000956:Antigens, Viral / Q000032:analysis; D002460:Cell Line; D003588:Cytopathogenic Effect, Viral; D005455:Fluorescent Antibody Technique; D006382:Hemadsorption; D007372:Interferons / Q000096:biosynthesis; D008459:Measles virus / Q000254:growth & development* / Q000276:immunology; D013696:Temperature; D014762:Viral Interference; D010948:Viral Plaque Assay; D014776:Virus Cultivation; D014779:Virus Replication
chemical_list: D000956:Antigens, Viral; D007372:Interferons