Ligand recognition by antigen-presenting cell C-type lectin receptors

It is now appreciated that the range of ligands interacting with C-type lectin type receptors on antigen presenting cells includes endogenous self-molecules as well as pathogens and pathogen-derived ligands. Interestingly, not all interactions between these receptors and pathogenic ligands have beneficial outcomes, and it appears that some pathogens have evolved immunoevasive or immunosuppressive activities through receptors such as DC-SIGN. In addition to this, recent data indicate that the well-characterised macrophage mannose receptor is not essential to host defence against fungal pathogens, as previously thought, but has an important role in regulating endogenous glycoprotein clearance. New studies have also demonstrated that different ligand binding and/or sensing receptors collaborate for full and effective immune responses.