Epstein Barr Virus Glycoproteins and their Roles in Virus Entry and Egress

Abstract

Much of the investigation of the biology of EBV has naturally and appropriately focussed on its extraordinary transforming potential. As the field matures, however, more attention can legitimately be given to the function of those proteins that are responsible for the production of new virus. This chapter has considered work on only the first and last steps in this process that involve membrane proteins, but even this limited arena has produced several biologically important discoveries and has raised perhaps even more provocative questions. Examination of the entry process and idenfitication of at least some of the proteins involved has revealed interactions that have, and should continue to provide important insights into tropism and pathogenesis. An understanding of the fusion process itself is still, however, almost completely lacking and is an issue that urgently needs creative investigation. Studies of virus assembly and egress are still in their infancy, but already have revealed a complex process that may provide insight not only into virus function, but also into the more fundamental processes of vesicular trafficking in the cell. In this area it seems likely that work done with herpesviruses in which it has area it seems likely that work done with herpesviruses in which it has historically been easier to study lytic replication may lead the way. It is, however, already clear that each virus has evolved in a somewhat different way to exploit its own biological niche, so surprises should be expected. Finally, although this chapter considers only the essential replicative functions of virus membrane proteins it must be noted that many of them certainly play additional more subtle roles in vivo. Those roles may be more difficult to to identify, except by analysis and analogy with closely related primate viruses, but are probably nonetheless critical to explaining the extraordinary success of EBV as a universal parasite of man.