Specific plasma membrane receptors for reovirus on rat pituitary cells in culture.

A B S T R A C T Specific cellular and host tropism is a characteristic property of many viruses mediated by the interaction of viral attachment proteins with components of the plasma membrane of the cell. We have studied the binding of virus to cells quantitatively by using type 3 reovirus labeled with 125I and GH,Cj pituitary cells in culture. Binding was rapid at both 40 and 15°C and was stable over a 9-h period. Unlabeled virus inhibited binding of the labeled virus in a dosedependent manner. Scatchard analysis revealed 4,200 viral binding sites/cell with an apparent affinity of 1.2 X 10" M. Also, binding of type 3 reovirus was inhibited by antibodies directed against the viral hemagglutinin and partially inhibited by type 2 reovirus, but was unaffected by type 1 reovirus or a variety of other ligands that bind to receptors on GH4Cj cells. These data indicate that reovirus binds to a high affinity, specific receptor on target cells, which may control its tropism and ultimate disease expression.