A peripheral membrane protein that is interactive with lymphocytic choriomeningitis virus (LCMV) was purified from cells permissive to infection. Tryptic peptides from this protein were determined to be alpha-dystroglycan (alpha-DG). Several strains of LCMV and other arenaviruses, including Lassa fever virus (LFV), Oliveros, and Mobala, bound to purified alpha-DG protein. Soluble alpha-DG blocked both LCMV and LFV infection. Cells bearing a null mutation of the gene encoding DG were resistant to LCMV infection, and reconstitution of DG expression in null mutant cells restored susceptibility to LCMV infection. Thus, alpha-DG is a cellular receptor for both LCMV and LFV.

Among cells of the immune system, CD11c+ and DEC-205+ splenic dendritic cells primarily express the cellular receptor (α-dystroglycan [α-DG]) for lymphocytic choriomeningitis virus (LCMV). By selection, strains and variants of LCMV that bind α-DG with high affinity are associated with virus replication in the white pulp, show preferential replication in a majority of CD11c+ and DEC-205+ cells, cause immunosuppression, and establish a persistent infection. In contrast, viral strains and variants that bind with low affinity to α-DG are associated with viral replication in the red pulp, display minimal replication in CD11c+ and DEC-205+ cells, and generate a robust anti-LCMV cytotoxic T lymphocyte response that clears the virus infection. Differences in binding affinities can be mapped to a single amino acid change in the viral glycoprotein 1 ligand that binds to α-DG. These findings indicate that receptor–virus interaction on dendritic cells in vivo can be an essential step in the initiation of virus-induced immunosuppression and viral persistence.