Novel Baculovirus Expression Vectors That Provide Sialylation of Recombinant Glycoproteins in Lepidopteran Insect Cells

This report describes novel baculovirus vectors designed to express mammalian β1,4-galactosyltransferase and α2,6-sialyltransferase genes at early times after infection. Sf9 cells infected with these viral vectors, unlike cells infected with a wild-type baculovirus, produced a sialylated viral glycoprotein during the late phase of infection. Thus, the two mammalian glycosyltransferases encoded by these viral vectors are necessary and sufficient for sialylation of a foreign glycoprotein in insect cells under the conditions used in this study. While some of the new baculovirus vectors described in this study produced less, one produced wild-type levels of infectious budded virus progeny.