title: Phenotypic and genetic analyses of the heterogeneous population present in the cold-adapted master donor strain: A/Leningrad/134/17/57 (H2N2).
abstract: For the past three decades the cold-adapted (ca) and temperature sensitive (ts) master donor strain, A/Leningrad/134/17/57 (H2N2) has been successfully used as the basis for the live attenuated reassortant influenza A vaccine. This donor strain was developed from A/Leningrad/134/57 (H2N2) wild-type (wt) virus following 17 passages in eggs at 25 degrees C. Our detailed investigation has revealed that the A/Leningrad/134/17/57 (Len/17) master donor stock is a mixed population comprised of numerous variants of the ca/ts Len/17 influenza virus. We have identified these variants to exhibit a broad range in their temperature sensitive phenotype when assayed on Madin-Darby canine kidney (MDCK) cells at 37 degrees C. A selection of these variant clones has been fully characterized by sequencing in order to understand the variability in the ts phenotype. This study has also addressed the feasibility of using cell culture technology for the propagation and subsequent manufacturing of the cold-adapted influenza vaccine (CAIV), particularly with respect to retaining the defined mutations that contribute toward the ca/ts phenotype.
authors.affiliation: Department of Virus and Cell Biology, Merck & Co. Inc., 770 Sumneytown Pike, WP44L-206B West Point, PA 19486, USA. rima_youli@merck.com
authors.forename: R
authors.initials: R
authors.lastname: Youil
authors.forename: I
authors.initials: I
authors.lastname: Kiseleva
authors.forename: W-S
authors.initials: WS
authors.lastname: Kwan
authors.forename: C
authors.initials: C
authors.lastname: Szymkowiak
authors.forename: T J
authors.initials: TJ
authors.lastname: Toner
authors.forename: Q
authors.initials: Q
authors.lastname: Su
authors.forename: A
authors.initials: A
authors.lastname: Klimov
authors.forename: L
authors.initials: L
authors.lastname: Rudenko
authors.forename: A R
authors.initials: AR
authors.lastname: Shaw
mesh_terms: D000222:Adaptation, Physiological; D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D003080:Cold Temperature; D014644:Genetic Variation; D053121:Influenza A Virus, H2N2 Subtype; D009980:Influenza A virus / Q000235:genetics* / Q000254:growth & development* / Q000302:isolation & purification; D007252:Influenza Vaccines; D020125:Mutation, Missense; D010063:Ovum / Q000821:virology; D010641:Phenotype; D020539:Sequence Analysis, Protein; D013696:Temperature; D014709:Vero Cells; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D014776:Virus Cultivation
chemical_list: D007252:Influenza Vaccines; D014764:Viral Proteins