TY - JOUR
T1 - Identification of mutations contributing to the temperature-sensitive, cold-adapted, and attenuation phenotypes of the live-attenuated cold-passage 45 (cp45) human parainfluenza virus 3 candidate vaccine
AU - Skiadopoulos, Mario H.
AU - Surman, Sonja
AU - Tatem, Joanne M.
AU - Paschalis, Maribel
AU - Wu, Shin Lu
AU - Udem, Stephen A.
AU - Durbin, Anna P.
AU - Collins, Peter L.
AU - Murphy, Brian R.
PY - 1999
Y1 - 1999
N2 - The live-attenuated human parainfluenza virus 3 (PIV3) cold-passage 45 (cp45) candidate vaccine was shown previously to be safe, immunogenic, and phenotypically stable in seronegative human infants. Previous findings indicated that each of the three amino acid substitutions in the L polymerase protein of cp45 independently confers the temperature-sensitive (ts) and attenuation (att) phenotypes but not the cold-adaptation (ca) phenotype (29). cp45 contains 12 additional potentially important point mutations in other proteins (N, C, M, F, and hemagglutinin-neuraminidase [HN]) or in cis-acting sequences (the leader region and the transcription gene start [GS] signal of the N gene), and their contribution to these phenotypes was undefined. To further characterize the genetic basis for the ts, ca, and att phenotypes of this promising vaccine candidate, we constructed, using a reverse genetics system, a recombinant cp45 virus that contained all 15 cp45-specific mutations mentioned above, and found that it was essentially indistinguishable from the biologically derived cp45 on the basis of plaque size, level of temperature sensitivity, cold adaptation, level of replication in the upper and lower respiratory tract of hamsters, and ability to protect hamsters from subsequent wild-type PIV3 challenge. We then constructed recombinant viruses containing the cp45 mutations in individual proteins as well as several combinations of mutations. Analysis of these recombinant viruses revealed that multiple cp45 mutations distributed throughout the genome contribute to the ts, ca, and att phenotypes. In addition to the mutations in the L gene, at least one other mutation in the 3' N region (i.e., including the leader, N GS, and N coding changes) contributes to the ts phenotype. A recombinant virus containing all the cp45 mutations except those in L was more ts than cp45, illustrating the complex nature of this phenotype. The ca phenotype of cp45 also is a complex composite phenotype, reflecting contributions of at least three separate genetic elements, namely, mutations within the 3' N region, the L protein, and the C-M-F-HN region. The att phenotype is a composite of both ts and non-is mutations. Attenuating ts mutations are located in the L protein, and non-ts attenuating mutations are located in the C and F proteins. The presence of multiple ts and non-ts attenuating mutations in cp45 likely contributes to the high level of attenuation and phenotypic stability of this promising vaccine candidate.
AB - The live-attenuated human parainfluenza virus 3 (PIV3) cold-passage 45 (cp45) candidate vaccine was shown previously to be safe, immunogenic, and phenotypically stable in seronegative human infants. Previous findings indicated that each of the three amino acid substitutions in the L polymerase protein of cp45 independently confers the temperature-sensitive (ts) and attenuation (att) phenotypes but not the cold-adaptation (ca) phenotype (29). cp45 contains 12 additional potentially important point mutations in other proteins (N, C, M, F, and hemagglutinin-neuraminidase [HN]) or in cis-acting sequences (the leader region and the transcription gene start [GS] signal of the N gene), and their contribution to these phenotypes was undefined. To further characterize the genetic basis for the ts, ca, and att phenotypes of this promising vaccine candidate, we constructed, using a reverse genetics system, a recombinant cp45 virus that contained all 15 cp45-specific mutations mentioned above, and found that it was essentially indistinguishable from the biologically derived cp45 on the basis of plaque size, level of temperature sensitivity, cold adaptation, level of replication in the upper and lower respiratory tract of hamsters, and ability to protect hamsters from subsequent wild-type PIV3 challenge. We then constructed recombinant viruses containing the cp45 mutations in individual proteins as well as several combinations of mutations. Analysis of these recombinant viruses revealed that multiple cp45 mutations distributed throughout the genome contribute to the ts, ca, and att phenotypes. In addition to the mutations in the L gene, at least one other mutation in the 3' N region (i.e., including the leader, N GS, and N coding changes) contributes to the ts phenotype. A recombinant virus containing all the cp45 mutations except those in L was more ts than cp45, illustrating the complex nature of this phenotype. The ca phenotype of cp45 also is a complex composite phenotype, reflecting contributions of at least three separate genetic elements, namely, mutations within the 3' N region, the L protein, and the C-M-F-HN region. The att phenotype is a composite of both ts and non-is mutations. Attenuating ts mutations are located in the L protein, and non-ts attenuating mutations are located in the C and F proteins. The presence of multiple ts and non-ts attenuating mutations in cp45 likely contributes to the high level of attenuation and phenotypic stability of this promising vaccine candidate.
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U2 - 10.1128/jvi.73.2.1374-1381.1999
DO - 10.1128/jvi.73.2.1374-1381.1999
M3 - Article
C2 - 9882342
AN - SCOPUS:0032949144
SN - 0022-538X
VL - 73
SP - 1374
EP - 1381
JO - Journal of virology
JF - Journal of virology
IS - 2
ER -