Even after nearly a year of intensive study, SARS-CoV-2 continues to surprise us. Experts at France's Interdisciplinary Research Institute of Grenoble (IRIG) have uncovered a previously unknown mechanism: the virus hijacks immune cells to boost its spread.
Crafting effective vaccines and therapies demands a deep understanding of SARS-CoV-2's behavior in the body, especially its cellular entry points. Cell surfaces feature receptors that viruses exploit—some for binding, others acting as literal locks. Viruses deploy surface proteins to pick these locks and invade.
The spike glycoprotein S on SARS-CoV-2 binds to the ACE2 receptor to enter human cells. In a preprint published on bioRxiv on August 10, 2020, IRIG researchers revealed that additional receptors also aid entry.
The team identified lectin family proteins (DC-SIGN, L-SIGN, MGL, and Langerin) on immune cells. These enable multi-site recognition of the spike protein via its surface glycans (sugars), facilitating viral proliferation. While not causing direct infection, receptors like DC-SIGN and L-SIGN transfer the virus to ACE2-equipped permissive cells.
Study leaders describe this as a novel transmission pathway in the infection process. Promisingly, glycomimetics developed at the CEA-Irig Institute of Structural Biology can inhibit it.
This work is a preprint under peer review for validation.
