MARCO

Macrophage receptor MARCO also known as macrophage receptor with collagenous structure (MARCO) is a is_associated_with::protein that in humans is encoded by the MARCO is_associated_with::gene.

Function
The protein encoded by this gene is a member of the class A scavenger receptor family and is part of the innate antimicrobial immune system. The protein may bind both Gram-negative and Gram-positive bacteria via an extracellular, C-terminal, scavenger receptor cysteine-rich (SRCR) domain. In addition to short cytoplasmic and transmembrane domains, there is an extracellular spacer domain and a long, extracellular collagenous domain. The protein may form a trimeric molecule by the association of the collagenous domains of three identical polypeptide chains.

Infused, negatively charged, immune-modifying microparticles (IMPs), derived from polystyrene, microdiamonds, or biodegradable poly(lactic-co-glycolic) acid, are taken up by inflammatory monocytes, in an opsonin-independent fashion, via MARCO. This results in monocyte sequestration in the spleen through apoptotic cell clearance mechanisms. IMPs may therefore be of therapeutic use in diseases caused or potentiated by inflammatory monocytes.