Novel baculovirus expression vectors that provide sialylation of recombinant glycoproteins in lepidopteran insect cells

This report describes novel baculovirus vectors designed to express mammali an beta1,4-galactosyltransferase and alpha2,6-sialyltransferase genes at ea rly times after infection. Sf9 cells infected with these viral vectors, unl ike cells infected with a wild-type baculovirus, produced a sialylated vira l glycoprotein during the late phase of infection. Thus, the two mammalian glycosyltransferases encoded by these viral vectors are necessary and suffi cient for sialylation of a foreign glycoprotein in insect cells under the c onditions used in this study. While some of the new baculovirus vectors des cribed in this study produced less, one produced wild-type levels of infect ious budded virus progeny.