Generation of defective interfering particles by two vaccine strains of measles virus.
A systematic study was made to measure the generation of defective interfering particles upon up to 13 serial passages of two measles vaccine strains, Edmonston and Edmonston-Zagreb, through either simian (Vero) or human (WI-38) cell lines. Results for the Vero cell passage were nearly identical for both viruses. Infectivity titers dropped by nearly 8 logs to undetectable levels at passage 4 and cycled between maximum and minimum levels every 4 passages. Samples with the lowest infectivity titers produced the greatest reduction in titer of standard virus and contained an approximately 900-nucleotide subgenomic RNA for the Edmonston strain and two subgenomic RNAs of 4300 and 3000 nucleotides for the Edmonston-Zagreb vaccine strain. A defective interfering RNA-specific reverse transcription-polymerase chain reaction (RT-PCR) detected subgenomic RNAs at all passage levels. In contrast, samples obtained after passage of these viruses in WI-38 did not reduce the yield of standard virus and did not contain subgenomic RNAs in both Northern blot and RT-PCR assays. These results clearly show that cell type rather than virus strain affects defective interfering particle generation for measles virus.
Whistler
T
T
Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
Bellini
W J
WJ
Rota
P A
PA
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D004279:DNA, Viral; D003673:Defective Viruses / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008458:Measles Vaccine / Q000235:genetics*; D008459:Measles virus / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000032:analysis; D012692:Serial Passage; D014709:Vero Cells; D014779:Virus Replication
D004279:DNA, Viral; D008458:Measles Vaccine; D012367:RNA, Viral