title: Differences in Establishment of Persistence of Vaccine and Wild Type Rubella Viruses in Fetal Endothelial Cells.
abstract: Both wild type (WT) and vaccine rubella virus (RV) can pass through the placenta to infect a human fetus, but only wtRV routinely causes pathology. To investigate possible reasons for this, we compared establishment of persistence of wtRV and RA27/3 vaccine strains in fetal endothelial cells. We showed that yields of RA27/3 and wtRV were similar after the first round of replication, but then only vaccine-infected cultures went through a crisis characterized by partial cell loss and gradual decline of virus titer followed by recovery and establishment of persistent cultures with low levels of RA27/3 secretion. We compared various steps of virus replication, but we were unable to identify changes, which might explain the 2-log difference in RA27/3 and wtRV yields in persistently infected cultures. Whole genome sequencing did not reveal selection of virus variants in either the wtRV or RA27/3 cultures. Quantitative single-cell analysis of RV replication by in situ hybridization detected, on average, 1-4 copies of negative-strand RNA and ~50 copies of positive-strand genomic RNA in cells infected with both vaccine and WT viruses. The distinct characteristics of RA27/3 replication were the presence of large amounts of negative-strand RV RNA and RV dsRNA at the beginning of the crisis and the accumulation of high amounts of genomic RNA in a subpopulation of infected cells during crisis and persistence. These results suggest that RA27/3 can persist in fetal endothelial cells, but the characteristics of persistence and mechanisms for the establishment and maintenance of persistence are different from wtRV.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Perelygina
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Adebola
authors.initials: A
authors.lastname: Adebayo
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Maureen
authors.initials: M
authors.lastname: Metcalfe
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Joseph
authors.initials: J
authors.lastname: Icenogle
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002452:Cell Count; D002522:Chlorocebus aethiops; D005333:Fetus / Q000166:cytology*; D005455:Fluorescent Antibody Technique; D061307:Human Umbilical Vein Endothelial Cells / Q000821:virology*; D006801:Humans; D017403:In Situ Hybridization; D007700:Kinetics; D012367:RNA, Viral / Q000235:genetics; D012411:Rubella Vaccine / Q000276:immunology*; D012412:Rubella virus / Q000276:immunology*; D014709:Vero Cells; D014764:Viral Proteins / Q000378:metabolism; D014771:Virion / Q000648:ultrastructure; D014779:Virus Replication
chemical_list: D012367:RNA, Viral; D012411:Rubella Vaccine; D014764:Viral Proteins