Diagnostic potential of baculovirus-expressed rubella virus envelope proteins.
The envelope glycoproteins E1 and E2 of rubella virus were abundantly expressed in Spodoptera frugiperda Sf9 insect cells by using a baculovirus expression vector. The recombinant protein products were purified by immunoaffinity chromatography and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting, and enzyme immunoassay (EIA). The purified recombinant antigen consisted of the envelope polypeptides, corresponding to the viral E1 and E2 proteins, and a polyprotein precursor (molecular mass, 90 to 95 kDa). The antigen was reactive with human convalescent-phase sera in immunoblot analysis, and the reactivity correlated well (r = 0.861) with that of a whole-virus antigen when tested by EIA by using a total of 106 rubella virus immunoglobulin G-positive and -negative serum specimens. When the sera from patients with recent rubella virus infection were tested with the recombinant glycoproteins by EIA, the correlation was not as close (r = 0.690). However, all of the 26 serum specimens were reactive with the recombinant antigen. The results demonstrate that these bioengineered antigens have a potential for use in routine diagnostic assays of rubella virus immunity and recent infection.
Seppänen
H
H
Labsystems Research Laboratories, Helsinki, Finland.
Huhtala
M L
ML
Vaheri
A
A
Summers
M D
MD
Oker-Blom
C
C
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D000956:Antigens, Viral / Q000235:genetics / Q000302:isolation & purification; D016367:Baculoviridae / Q000235:genetics; D002460:Cell Line; D005822:Genetic Vectors; D006801:Humans; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification; D012409:Rubella / Q000175:diagnosis* / Q000276:immunology; D012412:Rubella virus / Q000235:genetics / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification
D000914:Antibodies, Viral; D000956:Antigens, Viral; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C061826:E1 envelope protein, Rubella virus; C061827:E2 envelope protein, Rubella virus