Cell surface expression of herpes simplex virus type 1 glycoprotein H in recombinant baculovirus-infected cells

DNA encoding the complete sequence for the herpes simplex virus type 1 (HSV-1) glycoprotein H (gH) was inserted into a baculovirus transfer vector under control of the baculovirus polyhedrin gene promoter. After co-transfection with wild-type baculovirus DNA, recombinants expressing gH were isolated by plaque purification. The baculovirus-expressed HSV-1 gH represented a significant portion of total cellular protein and was several hundred fold more abundant than gH in HSV-1-infected Vero cells. The expressed gH appeared to be glycosylated, since it was similar in size to wild-type HSV-1 gH, was susceptible to both tunicamycin and endoglycosidase-H treatment, and was labeled by [3H]mannose. In contrast to previous reports of gH expressed in mammalian cells, the baculovirus recombinant-expressed gH was abundant on the cell surface as judged by indirect immunofluorescence. To our knowledge, this is the first report of expressed HSV-1 gH being transported to the cell surface in the absence of other HSV-1 gene products and the first report of expressed gH with an apparent molecular weight similar to authentic HSV-1 gH.