Infectivity of a Human Respiratory Syncytial Virus Lacking the SH, G, and F Proteins Is Efficiently Mediated by the Vesicular Stomatitis Virus G Protein

AUTOR(ES)

Oomens, A. G. P.

FONTE

American Society for Microbiology

RESUMO

To examine the requirements of the human respiratory syncytial virus (HRSV) SH (small hydrophobic), G (attachment), and F (fusion) proteins for virus infectivity and morphology, we used the prototype A2 strain of HRSV to generate a series of cDNAs from which (i) the SH open reading frame (ORF), (ii) the SH and G ORFs, or (iii) the SH, G, and F ORFs were deleted. Each deleted ORF was replaced as follows: the SH ORF was replaced with that of green fluorescent protein; the G ORF was replaced with that of Gvsv, a chimeric glycoprotein consisting of the vesicular stomatitis Indiana virus (VSIV) G protein ecto- and transmembrane domains coupled to the HRSV F cytoplasmic tail; and the F ORF was replaced with that of marker protein β-glucuronidase. The number of genes and the intergenic junctions in the constructs were kept as found in A2 virus in order to maintain authentic levels of transcription. Infectious viruses were recovered from all three engineered cDNAs and designated RSΔsh, RSΔsh,g/Gvsv, and RSΔsh,g,f/Gvsv, respectively. Low-pH-induced syncytium formation was observed in cells infected with viruses RSΔSH,G/Gvsv and RSΔSH,G,F/Gvsv, indicating that Gvsv was expressed and functional. Neutralization of infectivity by anti-VSIV G antibodies and inhibition of entry by ammonium chloride showed that RSΔSH,G,F/Gvsv infectivity was mediated by Gvsv and that an acidification step was required for entry into the host cell, similar to VSIV virions. All three engineered viruses displayed growth kinetics and virus yields similar to a wild-type A2 virus, both in Vero and HEp-2 cells. Abundant virus-induced filaments were observed at the surface of cells infected with each of the three engineered viruses or with virus A2, indicating that neither the SH and G proteins nor the F protein ecto- and transmembrane domains were required for the formation of these structures. This is the first report of the recovery of an infectious HRSV lacking a fusion protein of the Paramyxoviridae family and of manipulation of the HRSV entry pathway via incorporation of a nonparamyxoviral transmembrane glycoprotein.

Documentos Relacionados

• Human cytotoxic T cells stimulated by antigen on dendritic cells recognize the N, SH, F, M, 22K, and 1b proteins of respiratory syncytial virus.
• Respiratory Syncytial Virus (RSV) Fusion Protein Subunit F2, Not Attachment Protein G, Determines the Specificity of RSV Infection
• The Baculovirus GP64 Protein Mediates Highly Stable Infectivity of a Human Respiratory Syncytial Virus Lacking Its Homologous Transmembrane Glycoproteins
• The Membrane-Proximal Region of Vesicular Stomatitis Virus Glycoprotein G Ectodomain Is Critical for Fusion and Virus Infectivity
• Respiratory syncytial virus (RSV) F, G, M2 (22K), and N proteins each induce resistance to RSV challenge, but resistance induced by M2 and N proteins is relatively short-lived.