title: Respiratory syncytial virus (RSV) SH and G proteins are not essential for viral replication in vitro: clinical evaluation and molecular characterization of a cold-passaged, attenuated RSV subgroup B mutant.
abstract: A live, cold-passaged (cp) candidate vaccine virus, designated respiratory syncytial virus (RSV) B1 cp-52/2B5 (cp-52), replicated efficiently in Vero cells, but was found to be overattenuated for RSV-seronegative infants and children. Sequence analysis of reverse-transcription-PCR-amplified fragments of this mutant revealed a large deletion spanning most of the coding sequences for the small hydrophobic (SH) and attachment (G) proteins. Northern blot analysis of cp-52 detected multiple unique read-through mRNAs containing SH and G sequences, consistent with a deletion mutation spanning the SH:G gene junction. Immunological studies confirmed that an intact G glycoprotein was not produced by the cp-52 virus. Nonetheless, cp-52 was infectious and replicated to high titer in tissue culture despite the absence of the viral surface SH and G glycoproteins. Thus, our characterization of this negative-strand RNA virus identified a novel replication-competent deletion mutant lacking two of its three surface glycoproteins. The requirement of SH and G for efficient replication in vivo suggests that selective deletion of one or both of these RSV genes may provide an alternative or additive strategy for developing an optimally attenuated vaccine candidate.
authors.affiliation: Center for Immunization Research, Department of International Health, School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, MD 21205, USA. rkarron@jhsph.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Karron
authors.forename: D A
authors.initials: DA
authors.lastname: Buonagurio
authors.forename: A F
authors.initials: AF
authors.lastname: Georgiu
authors.forename: S S
authors.initials: SS
authors.lastname: Whitehead
authors.forename: J E
authors.initials: JE
authors.lastname: Adamus
authors.forename: M L
authors.initials: ML
authors.lastname: Clements-Mann
authors.forename: D O
authors.initials: DO
authors.lastname: Harris
authors.forename: V B
authors.initials: VB
authors.lastname: Randolph
authors.forename: S A
authors.initials: SA
authors.lastname: Udem
authors.forename: B R
authors.initials: BR
authors.lastname: Murphy
authors.forename: M S
authors.initials: MS
authors.lastname: Sidhu
mesh_terms: D000818:Animals; D002648:Child; D002522:Chlorocebus aethiops; D002874:Chromosome Mapping; D017353:Gene Deletion; D005814:Genes, Viral; D015707:HN Protein; D006801:Humans; D007223:Infant; D009154:Mutation; D018357:Respiratory Syncytial Virus Infections / Q000517:prevention & control; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology*; D014613:Vaccines, Attenuated / Q000235:genetics; D014614:Vaccines, Synthetic / Q000235:genetics; D014709:Vero Cells; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000235:genetics* / Q000276:immunology / Q000502:physiology*; D014765:Viral Vaccines / Q000235:genetics; D014774:Virulence / Q000235:genetics; D014779:Virus Replication / Q000235:genetics
chemical_list: D015707:HN Protein; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014764:Viral Proteins; D014765:Viral Vaccines; C116204:attachment protein G