Interaction of reovirus with cell surface receptors. III. Reovirus type 3 induces capping of viral receptors on murine lymphocytes.

We have previously shown that there are receptors for the hemagglutinin of reovirus type 3 on a subset of both murine T and B cells. Using purified reovirus type 3 particles as a ligand, followed by FITC-labeled antiviral antibody we have now been able to demonstrate viral induced capping of the reovirus receptor on both B and T cells. Kinetic studies and inhibition experiments using cytochalasin B and colchicine demonstrate that reovirus-induced capping of the viral receptor on both B and T cells has characteristics identical to the capping of immunoglobulin on B cells by anti-immunoglobulin reagents. Removal of the viral receptor and reexpression after overnight culture was demonstrated after membrane treatment by proteolytic enzymes (trypsin, pronase) or after viral induced modulation of receptor. Protein synthesis was required for reexpression since cyclohexamide prevented the reexpression of receptor in culture. Co-capping studies utilizing 2-color immunofluorescence failed to identify and association between the reovirus receptor and a variety of known surface structures on either B or T cells, but demonstrated independent modulation of the viral receptor from other surface structures. These studies suggest that the lymphocyte surface binding site for reovirus type 3 is a distinct structure that behaves identically in capping studies of both B and T cells, is protein in nature, and is intimately linked to the cell cytoskeleton.