title: Two clones obtained from Urabe AM9 mumps virus vaccine differ in their replicative efficiency in neuroblastoma cells.
abstract: A high rate of post-vaccinal aseptic meningitis for Urabe AM9 mumps virus strain is well documented. This strain is composed of two virus variants differing at the nt 1081 (A/G) region in the hemagglutinin-neuraminidase (HN) gene. An association of HN-A(1081) variant with neurovirulence has been proposed. In order to test for neurotropism we isolated the HN-A(1081) and HN-G(1081) virus variants from Urabe AM9 mumps virus vaccine. Sequential passages were performed in monkey kidney Vero cells and human neuroblastoma SH-SY5Y cells. Viral replication was determined by conventional and real-time RT-PCR. The results show that clone HN-A(1081) can replicate efficiently in both cell types. However, a defective replication of clone HN-G(1081), lacking its genetic marker, was observed after the third passage in neuroblastoma cells. Kinetics assays showed that clone HN-A(1081) replicates faster than clone HN-G(1081). Viral clones were also inoculated into the brains of newborn rats. Clone HN-A(1081) replicated 14 times, while clone HN-G(1081) merely duplicated its level over the initial inoculum. These results suggest that there is a selective replication of HN-A(1081) mumps virus variants in cells of nervous origin.
authors.affiliation: Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508 Col. San Pedro Zacatenco CP 07360. México DF, Mexico.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Santos-López
authors.forename: Carlos
authors.initials: C
authors.lastname: Cruz
authors.forename: Nidia
authors.initials: N
authors.lastname: Pazos
authors.forename: Verónica
authors.initials: V
authors.lastname: Vallejo
authors.forename: Julio
authors.initials: J
authors.lastname: Reyes-Leyva
authors.forename: José
authors.initials: J
authors.lastname: Tapia-Ramírez
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000821:virology; D002460:Cell Line; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D015707:HN Protein / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D009107:Mumps / Q000821:virology; D009108:Mumps Vaccine; D009109:Mumps virus / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D009447:Neuroblastoma / Q000821:virology*; D017354:Point Mutation; D051381:Rats; D014709:Vero Cells; D014779:Virus Replication
chemical_list: D015707:HN Protein; D009108:Mumps Vaccine