Expression and characterisation of the ovine respiratory syncytial virus (ORSV) G protein for use as a diagnostic reagent

Respiratory syncytial virus (RSV) causes severe lower respiratory tract inf ection in children and calves. Antibodies to ovine RSV (ORSV) are common in sheep, but the clinical disease is not well defined. There is no report of ORSV infection in Australian sheep although respiratory distress syndrome has been described. This discrepancy may be due to the lack of a suitable d iagnostic test. In this report, we have characterised the ORSV G protein in an attempt to study its relatedness to human and bovine RSV (HRSV, BRSV) a nd for use in the development of a suitable diagnostic assay. Full length a nd a truncated variant of ORSV G protein were expressed in mammalian cells and the expressed proteins characterised by indirect immunofluorescence and radioimmunoprecipitation assays. Our results indicate that like HRSV, the ORSV G protein is heavily glycosylated. The expressed protein was membrane bound as well as secreted and could be purified from culture supernatants a nd may be suitable for use in development of a diagnostic assay. (C) Inra/E lsevier, Paris.