SPECIES SELECTIVE INTERACTION OF ALPHAHERPESVIRINAE WITH THE UNSPECIFIC IMMUNE-SYSTEM OF THE HOST

During evolution Herpesviridae have developed glycoproteins, which int eract with essential components of the immune system. Besides immunogl obulin-binding proteins (= Fc-receptors), expressed by several members of the herpesfamily, the interaction with the complement system plays a role in the pathogenicity of herpes simplex virus. Here we report t hat the ability to interact with the third complement component (C 3), the central mediator of complement activation, was also found among s everal animal alphaherpesviruses. This interaction appeared to be spec ies-selective as the viral proteins preferentially bound to the C 3 or iginated from the respective host. That could provide a possible expla nation for the evolution of a variety of herpesviruses as the species tropism observed among Herpesviridae may be influenced by specific ada ptation of protective virus-proteins to the immune system of the diffe rent hosts. The data have critical implications for the studies of vir us host interactions in heterologous systems and support a role for th e C 3-binding proteins in pathogenesis. Since the C 3-binding proteins are conserved among different herpesviruses they could serve as suita ble subunit-vaccine candidates.