RESUMEN
Herpes simplex virus (HSV) remains a major human pathogen worldwide (25 causing cold sores, eye and genital infections, blindness, encephalitis, and neonatal infections. Most adults have antibodies against the oral form of the virus HSV-1 (9), and a significant number are infected with the genital form, HSV-2. Both serotypes establish lifelong latent infections and reactivate periodically to produce recurrent disease (25). After infection, virus-encoded glycoproteins are expressed on all cellular membranes and are major targets of the host's immune response. The virion envelope contains 10 glycoproteins that are important for infection and pathogenesis of HSV-1 and HSV-2. Because HSV contains so many glycoproteins, sorting out their functions in virus entry remains a difficult task. Our approach has focused on establishing structure-function relationships of the individual glycoproteins with particular emphasis on gC and gD. After many years of studying the properties of these proteins in HSV-infected and plasmid-transfected mammalian cells, we have now begun to overexpress the proteins using a baculovirus expression system.
RESUMEN
Herpes simplex virus type 1-infected cells bind C3b and iC3b, but not C3d, at the cell surface. Herpes simplex virus type 2 (HSV-2)-infected cells bind none of these C3 fragments. A transfection assay was used to demonstrate that binding of iC3b was to gC1. Although iC3b did not bind to HSV-2-infected cells, it did bind to mammalian cells transfected with the gC2 gene. Using linker insertion mutants, three domains on gC2 that are important for binding iC3b were mapped; these regions were similar to previously defined regions involved in binding C3b. These results suggest that some of the functions served by gC may be similar to those of CR3, the mammalian receptor for iC3b.