An immunologically active chimaeric protein containing herpes simplex virus type 1 glycoprotein D

Abstract

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) cause both persistent and latent infections, including recurrent cutaneous disease, lethal neonatal disease, central nervous system disease and other clinical syndromes¹. Modified live vaccines or conventionally prepared subunit vaccines have generally been unsuccessful in the treatment of HSV-1 and HSV-2 infections from the standpoints of safety and efficacy². It has been established that HSV-1 and HSV-2 infectivity may be neutralized in vitro with antisera directed specifically against each of the four major glycoproteins of the virus (gA/gB, gC, gD and gE)^3,4 and antisera against glycoprotein gD, of either HSV-1 or HSV-2, are capable of neutralizing both HSV-1 and HSV-2 infectivity in vitro and in vivo^5–8. We have previously reported on the identification, DNA sequence and expression at low level in Escherichia coli of the gD gene of HSV-1 strain Patton⁹. Here we describe construction of a hybrid gene encoding a chimaeric protein containing HSV-1 gD, bacteriophage λ Cro and E. coli β-galactosidase (gD-β-gal) protein, which is expressed at high level in E. coli. Moreover, the chimaeric protein elicits antibodies in rabbits that not only immunoprecipitate gD from cells infected with HSV-1 and HSV-2 but also neutralize HSV-1 and HSV-2 infectivity in vitro.