Virus receptors: binding, adhesion strengthening, and changes in viral structure.
Abstract
ANNE M. HAYWOOD* Departments of Pediatrics and Microbiology, University of Rochester, Rochester, New York 14642 Virus receptors are one determinant of virus host range and tissue tropism. Virus binding was previously considered to involve simple recognition and attachment to a single cell surface molecule by virus attachment proteins (VAPs). As understanding of virus-host interactions expands, the definition of a virus receptor is changing. In this review, the term virus receptor is used to mean a host surface component that participates in virus binding and facilitates viral infection. Until the mid-1980s, the only virus receptors that were unequivocally identified were sialic acids for the myxoviruses and paramyxoviruses. Advances in technology have allowed the identification of many more virus receptors, and the list is rapidly growing. Further, data indicating that binding is a multistep process are accumulating. This review is meant to highlight some of the more recent developments and some of the questions they raise. IDENTIFICATION OF RECEPTORS Influenza A and B viruses and the paramyxoviruses were shown in the 1940s to have receptor-destroying enzymes that remove the virus's receptors from cells. In the late 1950s, these receptor-destroying enzymes were found to be neuraminidases, which cleave the glycoside linkage