BOVINE HERPESVIRUS-1 GLYCOPROTEIN-B DOES NOT PRODUCTIVELY INTERACT WITH CELL-SURFACE HEPARAN-SULFATE IN A PSEUDORABIES VIRION BACKGROUND

Attachment to cell surface heparan sulfate proteoglycans is the first step in infection by several alphaherpesviruses. This interaction is p rimarily mediated by virion glycoprotein C (gC). In herpes simplex vir us, in the absence of the nonessential gC, heparan sulfate binding is effected by glycoprotein B. In contrast, gC-negative pseudorabies viru s (PrV) infects target cells aa a heparan sulfate-independent mechanis m, indicating that PrV virion gB does not productively interact with h eparan sulfate. To assay whether a heterologous alphaherpesvirus gB pr otein will confer productive heparan sulfate binding on gC-negative Pr V, gC was deleted from an infectious PrV recombinant, PrV-9112C2, whic h expresses bovine herpesvirus 1 (BHV-1) gB instead of PrV gB. Our dat a show that gC-negative PrV-BHV-1 gB recombinant 9112C2-Delta gC beta was not inhibited in infection by soluble heparin, in contrast to the gC-positive parental strain. Similar results were obtained when wild-t ype BHV-1 was compared with a gC-negative BHV-1 mutant. Moreover, infe ction of cells proficient or deficient in heparan sulfate biosynthesis occurred with equal efficiency by PrV-9112C2-Delta gC beta, whereas h eparan sulfate-positive cells showed an approximately fivefold higher plating efficiency than heparan sulfate-negative cells with the parent al gC-positive virus. In summary, our data show that in a PrV gC-negat ive virion background, BHV-1 gE is not able to mediate infection by pr oductive interaction with heparan sulfate, and they indicate the same lack of heparin interaction for BHV-1 gB in gC-negative BHV-1.