Siglecs in innate immunity

Siglecs are sialic acid-binding Ig-like lectins expressed in a highly specific manner, and which are implicated in signaling and adhesive functions. The CD33-related siglecs represent a distinct subgroup that is undergoing rapid evolution within the innate immune system, with the potential to trigger apoptosis and provide inhibitory signals. CD22 is a well-characterised B cell restricted siglec that has been shown to mediate both sialic acid-dependent and -independent signaling functions in B cell regulation. As endocytic receptors, siglecs provide portals of entry for certain viral and bacterial pathogens, as well as therapeutic opportunities for targeting innate immune cells in disease.