Siglecs are SUPER important immune receptors that normally antagonise or induce tolerance in the immune system. Normally they recognise different sialic acids (e.g., the same ones recognised by hemaglutinin in influenza) and depending on the health of the cells you can induce different responses in your immune cells.

We’ve done a bit of work in our lab on these receptors, trying to figure out what their natural ligands are. Crazy that the carbon nanotubes are also recognised. I’ll need to check my notes, but I think that the loops that are recognising the nanotubes aren’t where the binding normally is for sialic acids, so it’s all very interesting!

Additional thoughts: I wonder if anyone has tried throwing viral particles or protein pathogens on a carbon nanotube to check for binding. The other Siglecs don’t interact, but hey, maybe we’re lucky and all these pathogen related sialic acid binders happen to have the right residues in place! The SRR bacterial adhesins off the top of my head might be candidates.