title: Generation of recombinant human parainfluenza virus type 1 vaccine candidates by importation of temperature-sensitive and attenuating mutations from heterologous paramyxoviruses.
abstract: Human parainfluenza virus type 1 (HPIV1) is a significant cause of respiratory tract disease in infants and young children for which a vaccine is needed. In the present study, we sought to attenuate HPIV1 by the importation of one or more known attenuating point mutations from heterologous paramyxoviruses into homologous sites in HPIV1. The introduced mutations were derived from three attenuated paramyxoviruses: (i) HPIV3cp45, a live-attenuated HPIV3 vaccine candidate containing multiple attenuating mutations; (ii) the respiratory syncytial virus cpts530 with an attenuating mutation in the L polymerase protein; and (iii) a murine PIV1 (MPIV1) attenuated by a mutation in the accessory C protein. Recombinant HPIV1 (rHPIV1) mutants bearing a single imported mutation in C, any of three different mutations in L, or a pair of mutations in F exhibited a 100-fold or greater reduction in replication in the upper or lower respiratory tract of hamsters. Both temperature-sensitive (ts) (mutations in the L and F proteins) and non-ts (the mutation in the C protein) attenuating mutations were identified. rHPIV1 mutants containing a combination of mutations in L were generated that were more attenuated than viruses bearing the individual mutations, showing that the systematic accretion of mutations can yield progressive increases in attenuation. Hamsters immunized with rHPIV1 mutants bearing one or two mutations developed neutralizing antibodies and were resistant to challenge with wild-type HPIV1. Thus, importation of attenuating mutations from heterologous viruses is an effective means for rapidly identifying mutations that attenuate HPIV1 and for generating live-attenuated HPIV1 vaccine candidates.
authors.affiliation: Respiratory Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Newman
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Riggs
authors.forename: Sonja R
authors.initials: SR
authors.lastname: Surman
authors.forename: Josephine M
authors.initials: JM
authors.lastname: McAuliffe
authors.forename: Teresa A
authors.initials: TA
authors.lastname: Mulaikal
authors.forename: Peter L
authors.initials: PL
authors.lastname: Collins
authors.forename: Brian R
authors.initials: BR
authors.lastname: Murphy
authors.forename: Mario H
authors.initials: MH
authors.lastname: Skiadopoulos
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001483:Base Sequence; D006224:Cricetinae; D006801:Humans; D008647:Mesocricetus; D008969:Molecular Sequence Data; D022241:Parainfluenza Vaccines / Q000235:genetics / Q000276:immunology*; D010222:Parainfluenza Virus 1, Human / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D010224:Parainfluenza Virus 3, Human / Q000235:genetics / Q000276:immunology; D010252:Paramyxoviridae / Q000235:genetics* / Q000276:immunology; D017354:Point Mutation; D012136:Respiratory Syncytial Viruses / Q000235:genetics / Q000276:immunology; D010253:Respirovirus Infections / Q000517:prevention & control*; D013696:Temperature; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology*; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D022241:Parainfluenza Vaccines; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014764:Viral Proteins