Fig. 2.

Strategies to manipulate Siglec-sialic-acid interactions. (A) Strategies which have been explored to enhance the inhibitory Siglec--mediated reduction of immunes response include 1) anti-Siglec antagonistic (blocking) antibody (tested against HIV- and HBV-infected cells), 2) sialyltransferase inhibitor to reduce the cell surface levels of sialic acids by inhibiting the enzyme involved in installing the sialic acid on cell surface, and 3) use of sialidase conjugated antibody recognizing the infected cell for targeted removal of sialic acids on infected cells (tested against HIV-infected cells). (B) Strategies have also been explored to suppress the excessive immune response which includes 1) engaging anti-Siglec antibodies (tested against SARS-CoV-2), 2) Sialic acid coated nanoparticles, and 3) cis-ligand agonist for Siglecs to keep Siglecs engaged (tested against SARS-CoV-2).