How alike are HSV-1 and HSV-2? In this feature, we look at the latest scientific facts about the two types of herpes simplex virus, as well as social attitudes toward oral and genital herpes.
Genital herpes is a common and highly contagious infection usually spread through sex. This infection is usually caused by the herpes simplex virus-2 (HSV-2) or the herpes simplex virus-1 (HSV-1), the virus usually responsible for cold sores. Genital herpes treatment includes medicines to help sores heal faster and prevent outbreaks.
In the case of a herpes virus, initial interactions occur when two viral envelope glycoprotein called glycoprotein C (gC) and glycoprotein B (gB) bind to a cell surface particle called heparan sulfate. Next, the major receptor binding protein, glycoprotein D (gD), binds specifically to at least one of three known entry receptors. These cell receptors include herpesvirus entry mediator (HVEM), nectin-1 and 3-O sulfated heparan sulfate. The nectin receptors usually produce cell-cell adhesion, to provide a strong point of attachment for the virus to the host cell. These interactions bring the membrane surfaces into mutual proximity and allow for other glycoproteins embedded in the viral envelope to interact with other cell surface molecules. Once bound to the HVEM, gD changes its conformation and interacts with viral glycoproteins H (gH) and L (gL), which form a complex. The interaction of these membrane proteins may result in a hemifusion state. gB interaction with the gH/gL complex creates an entry pore for the viral capsid. gB interacts with glycosaminoglycans on the surface of the host cell.