Fig. 4: Proposed mechanisms of debris clearance by the hepatic reticuloendothelial system.

Circulating debris is internalized through endocytosis (LSECs) or phagocytosis (Kupffer cells) in a size-dependent manner by receptors such as CD206, stabilin-1 and -2 and FcγRIIb2 specifically on LSECs. Subsequently, internalized particles are degraded through lysosomal enzymes. LSEC sieve plates facilitate macromolecule internalization. Conflicting reports exist on CD206 expression on Kupffer cells. *: Other receptors, including those listed in Table 4.