Galectin-3 plays a role in minute virus of mice infection.

Galectin-3 has previously been found to be required by the parvovirus minute virus of mice prototype strain (MVMp) for infection of mouse fibroblast cells. Since MVMp is an oncotropic virus, and galectin-3 is a multifunctional protein implicated in cancer metastasis, we hypothesized that galectin-3 and Mgat5, the Golgi enzyme that synthesizes high-affinity glycan ligands of galectin-3, might play a role in MVMp infection. Using siRNA-mediated knockdown of galectin-3 in mouse cells transformed with polyomavirus middle T antigen and Mgat5(-/-) mouse mammary tumor cells, we found that galectin-3 and Mgat5 are both necessary for efficient MVMp cell entry and infection, but not for cell binding. Moreover, we found that human cancer cells expressing higher levels of galectin-3 were more efficiently infected with MVMp than cell lines expressing lower galectin-3 levels. We conclude that galectin-3 and Mgat5 are involved in MVMp infection, and propose that galectin-3 is a determinant of MVMp oncotropism.