Isolation and characterization of the envelope glycoprotein of an avian osteopetrosis virus: Effect of host cell on antigenic reactivity

Abstract

Listen

Translate article

The physical and antigenic properties of the surface glycoprotein (gp85) of an avian myeloblastosis-associated virus [MAV-2(O)] were compared with those of avian myeloblastosis virus (AMV) gp85. Purified MAV-2(O) contained 3- to 4-fold higher levels of gp85 than AMV, as determined by polyacrylamide gel electrophoresis and guanidine hydrochloride column chromatography. The antigenic reactivity of MAV-2 (O) gp85 was examined in competition radioimmunoassays using rabbit antisera prepared against purified AMV and B77 gp85. The antigenic reactivity of MAV-2(O) as measured in competition radioimmunoassay using antiserum prepared against AMV gp85 depended on the source of the virus; MAV-2(O) isolated from chicken embryo fibroblast cultures showed considerably less antigenic reactivity than did MAV-2(O) isolated from the serum of osteopetrotic chickens. In contrast, MAV-2(O) from serum or grown in chicken embryo fibroblasts showed similar antigenic reactivities in competition radioimmunoassays using antiserum prepared against gp85 from B77. A comparison of the antigenic reactivities of the purified glycoproteins from MAV-2(O) (grown in fibroblasts) and AMV (isolated from plasma) demonstrated that the two glycoproteins showed equal reactivity using anti-B77 gp85 serum, but that MAV-2(O) gp85 showed at least 100-fold less antigenic reactivity than AMV gp85 in competition radioimmunoassay using anti-AMV gp85 serum. These results together with those previously published (Van Eldik et al., (1978). Virology 86, 193–204.) suggest that MAV-2(O) and AMV gp85 show similar host-dependent glycosylation patterns in vivo, which differ from the pattern observed when the viruses are grown in chicken embryo fibroblasts.