Characterization of recombinant respiratory syncytial viruses with the region responsible for type 2 T-cell responses and pulmonary eosinophilia deleted from the attachment (G) protein.
It is essential that preventative vaccines for respiratory syncytial virus (RSV) elicit balanced T-cell responses. Immune responses dominated by type 2 T cells against RSV antigens are believed to cause exaggerated respiratory tract disease and may also contribute to unwanted inflammation in the airways that predisposes infants to wheeze through adolescence. Here we report on the construction and characterization of recombinant RSV (rRSV) strains with amino acids 151 to 221 or 178 to 219 of the attachment (G) glycoprotein deleted (rA2cpDeltaG150-222 or rA2cpDeltaG177-220, respectively). The central ectodomain was chosen for modification because a peptide spanning amino acids 149 to 200 of G protein has recently been shown to prime several strains of naïve inbred mice for polarized type 2 T-cell responses, and peripheral blood T cells from most human donors recognize epitopes within this region. Quantitative PCR demonstrated that synthesis of nascent rRSV genomes in human lung epithelial cell lines was similar to that for the parent virus (cp-RSV). Plaque assays further indicated that rRSV replication was not sensitive to 37 degrees C, but pinpoint morphology was observed at 39 degrees C. Both rRSV strains replicated in the respiratory tracts of BALB/c mice and elicited serum neutralization and anti-F-protein immunoglobulin G titers that were equivalent to those elicited by cp-RSV and contributed to a 3.9-log(10)-unit reduction in RSV A2 levels 4 days after challenge. Importantly, pulmonary eosinophilia was significantly diminished in BALB/c mice primed with native G protein and challenged with either rA2cpDeltaG150-222 or rA2cpDeltaG177-220. These findings are important for the development of attenuated RSV vaccines.
Department of Immunology, Wyeth Vaccines Research, 401 N. Middletown Rd., Pearl River, NY 10965, USA.
Matthew B
MB
Elliott
Karin S
KS
Pryharski
Qingzhong
Q
Yu
L A
LA
Boutilier
N
N
Campeol
K
K
Melville
Todd S
TS
Laughlin
C K
CK
Gupta
Robert A
RA
Lerch
Valerie B
VB
Randolph
Natisha A
NA
LaPierre
Kristen M Heers
KM
Dack
Gerald E
GE
Hancock
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002460:Cell Line; D002522:Chlorocebus aethiops; D005260:Female; D006801:Humans; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011657:Pulmonary Eosinophilia; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology / Q000517:prevention & control / Q000821:virology; D022261:Respiratory Syncytial Virus Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity / Q000502:physiology; D017384:Sequence Deletion; D018418:Th2 Cells / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology; D014779:Virus Replication
D000914:Antibodies, Viral; D022261:Respiratory Syncytial Virus Vaccines; D014614:Vaccines, Synthetic; D014764:Viral Proteins