The recognition event between virus and host cell receptor: a target for antiviral agents.

Infection of cells by viruses begins with the attachment of the virus to the surface of the host cell (Dales, 1973; Lonberg-Holm & Philipson, 1974; Dimmock, 1982; Tardieu et al., 1982; Paulson, 1985; Marsh & Helenius, 1989). Attachment is mediated by the binding of a viral attachment protein (VAP) to a molecule on the cell surface acting as a virus receptor. The VAPs are the polypeptides forming the coat of enveloped viruses and the capsid of non-enveloped viruses. The virus receptor is potentially any normal constituent comprising or associated with the host cell membrane. The attachment step of the viral infectious cycle represents an ideal target for agents that prevent infection by inhibiting the attachment of virus to the host cell receptor. In order to develop agents that prevent attachment, it is necessary to identify the binding domains of the VAP and of the virus receptor and determine how they interact at a molecular level. In recent years, several host cell receptors for viruses have been identified as well as the regions of the receptor and VAP that mediate binding. In addition, there are many examples of agents that prevent infection by targeting the recognition event between virus and cell. This review summarizes current information on the binding domains of host cell receptors and VAPs and reviews examples where this knowledge serves as a basis for the rational development of agents that block the interaction of viruses with host cell receptors.