title: A genotype of modified vaccinia Ankara (MVA) that facilitates replication in suspension cultures in chemically defined medium.
abstract: While vectored vaccines, based on hyperattenuated viruses, may lead to new treatment options against infectious diseases and certain cancers, they are also complex products and sometimes difficult to provide in sufficient amount and purity. To facilitate vaccine programs utilizing host-restricted poxviruses, we established avian suspension cell lines (CR and CR.pIX) and developed a robust, chemically defined, culturing process for production of this class of vectors. For one prominent member, modified vaccinia Ankara (MVA), we now describe a new strain that appears to replicate to greater yields of infectious units, especially in the cell-free supernatant of cultures in chemically defined media. The new strain was obtained by repeated passaging in CR suspension cultures and, consistent with reports on the exceptional genetic stability of MVA, sequencing of 135 kb of the viral genomic DNA revealed that only three structural proteins (A3L, A9L  and A34R) each carry a single amino acid exchange (H639Y, K75E and D86Y, respectively). Host restriction in a plaque-purified isolate of the new genotype appears to be maintained in cell culture. Processing towards an injectable vaccine preparation may be simplified with this strain as a complete lysate, containing the main burden of host cell contaminants, may not be required anymore to obtain adequate yields.
authors: ProBioGen AG, Goethestr. 54, 13086 Berlin, Germany. ingo.jordan@probiogen.de
authors: Ingo
authors: I
authors: Jordan
authors: Deborah
authors: D
authors: Horn
authors: Katrin
authors: K
authors: John
authors: Volker
authors: V
authors: Sandig
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002685:Chiroptera; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism*; D004372:Ducks; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D014615:Vaccinia / Q000821:virology*; D014616:Vaccinia virus / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D015678:Viral Structural Proteins / Q000235:genetics / Q000378:metabolism; D014776:Virus Cultivation; D014779:Virus Replication
chemical_list: D003470:Culture Media; D015678:Viral Structural Proteins