Mouse anti-Human CD300LF monoclonal antibody, clone VQ-E3 [Biotin]

Noroviruses (NoVs) are a leading cause of gastroenteritis globally, yet the host factors required for NoV infection are poorly understood. We identified host molecules that are essential for murine NoV (MNoV)-induced cell death, including CD300lf as a proteinaceous receptor. We found that CD300lf is essential for MNoV binding and replication in cell lines and primary cells. Additionally, Cd300lf(-/-) mice are resistant to MNoV infection. Expression of CD300lf in human cells breaks the species barrier that would otherwise restrict MNoV replication. The crystal structure of the CD300lf ectodomain reveals a potential ligand-binding cleft composed of residues that are critical for MNoV infection. Therefore, the presence of a proteinaceous receptor is the primary determinant of MNoV species tropism, whereas other components of cellular machinery required for NoV replication are conserved between humans and mice.

Three recent papers highlight the impact of an entry receptor on murine norovirus pathogenesis. CD300lf was shown to be the first proteinaceous entry receptor for a norovirus, specialized intestinal epithelial cells constitute the reservoir for persistence, and a new link between the receptor and a lipid biosynthetic enzyme was revealed.