Elucidation of the full genetic information of Japanese rubella vaccines and the genetic changes associated with in vitro and in vivo vaccine virus phenotypes.
Rubella is a mild disease characterized by low-grade fever, and a morbilliform rash, but causes congenital defects in neonates born from mothers who suffered from rubella during the pregnancy. After many passages of wild-type rubella virus strains in various types of cultured cells, five live attenuated rubella vaccines were developed in Japan. An inability to elicit anti-rubella virus antibodies in experimentally infected animals was used as an in vivo marker phenotype of Japanese rubella vaccines. All Japanese rubella vaccine viruses exhibit a temperature-sensitive (ts) phenotype, and replicate very poorly at a high temperature. We determined the entire genome sequences of three Japanese rubella vaccines (Matsuba, TCRB19, and Matsuura), thereby completing the sequencing of all five Japanese rubella vaccines. In addition, the entire genome sequences of three vaccine progenitors were determined. Comparative nucleotide sequence analyses revealed mutations that were introduced into the genomes of the TO-336 and Matsuura vaccines during their production by laboratory passaging. Analyses involving cellular expression of viral P150 nonstructural protein-derived peptides revealed that the N1159S mutation conferred the ts phenotype on the TO-336 vaccine, and that reduced thermal stability of the P150 protease domain was a cause of the ts phenotype of some rubella vaccine viruses. The ts phenotype of vaccine viruses was not necessarily correlated with their inability to elicit humoral immune responses in animals. Therefore, the molecular mechanisms underlying the inability of these vaccines to elicit humoral responses in animals are more complicated than the previously considered mechanism involving the ts phenotype as the major cause.
Department of Virology 3, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashimurayama, Tokyo 208-0011, Japan. otsuki@nih.go.jp
Noriyuki
N
Otsuki
Hitoshi
H
Abo
Toru
T
Kubota
Yoshio
Y
Mori
Yukiko
Y
Umino
Kiyoko
K
Okamoto
Makoto
M
Takeda
Katsuhiro
K
Komase
D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D004252:DNA Mutational Analysis; D006168:Guinea Pigs; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010641:Phenotype; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D012411:Rubella Vaccine / Q000235:genetics* / Q000276:immunology*; D012412:Rubella virus / Q000235:genetics* / Q000276:immunology / Q000502:physiology / Q000528:radiation effects; D017422:Sequence Analysis, DNA; D012692:Serial Passage; D013696:Temperature; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics; D014779:Virus Replication / Q000528:radiation effects
D012367:RNA, Viral; D012411:Rubella Vaccine; D014613:Vaccines, Attenuated; D014764:Viral Proteins