Processing, secretion, and immunoreactivity of carboxy terminally truncated dengue-2 virus envelope proteins...

Two recombinant baculoviruses were constructed by inserting via the transfer vector pAcYM1 the genes coding for the structural proteins of dengue (DEN)-2 virus downstream from the polyhedrin promoter of Autographa californica nuclear polyhedrosis virus. The two recombinants differed in truncation of 26 and 71 amino acids, respectively, in the carboxy-terminal sequence of DEN-specific envelope (E) glycoprotein. Recombinant DEN-2 E glycoproteins were processed and transported to the surface of Spodoptera frugiperda Sf9 cells infected with both viruses. We show that about one-third of the E glycoprotein minus its whole C-terminal hydrophobic anchor domain was secreted into an endoglycosidase H-resistant form. The type-specific neutralizing epitopes were conserved in the recombinant proteins as shown with a panel of monoclonal antibodies.