Respiratory syncytial virus G glycoprotein expressed using the Semliki Forest virus replicon is biologically active
- 39 Downloads
The respiratory syncytial virus (RSV) G glycoprotein mediates attachment of RSV to cells via an unknown receptor. To study G glycoprotein function we have cloned two variants of the RSV G gene into a Semliki Forest virus (SFV) expression vector, a full length (rG) and soluble (srG) G glycoprotein variant. By immunofluorescence microscopy, rG was found to be predominantly membrane associated, while srG was mostly cytoplasmic. The rG (80–85 kDa) and srG (75–80 kDa) constructs produced heavily glycosylated proteins, however they were slightly smaller than the G glycoprotein expressed in RSV infected HEp-2 cells (85–90 kDa). The biological activity of purified srG was tested by its ability to bind to RSV permissive cells. Purified srG bound to HEp-2 cells and the amount bound increased linearly with the quantity added. Binding was not saturable with the small quantities of protein available. Binding of srG to HEp-2 cells was inhibited (67–68%) by MAb 30 and neutralising anti-G MAb 29. Nonpermissive SF9 insect cells bound 20–50 times less srG than HEp-2 cells. SFV expressed recombinant RSV G glycoprotein should be useful for studying interactions between the RSV G glycoprotein and cells.
Unable to display preview. Download preview PDF.