Collectin-10 (CL-10)

Collectin-10 (CL-10), also known as collectin liver 1 (CL-L1) or Collectin-34 (CL-34), is a protein encoded by the gene COLEC10. It belongs to the family of collagenous Ca²⁺-dependent (C-type) lectins which contains triple-helical collagen-like domains as well as C-terminal Ca²⁺-dependent lectin domains. In addition to CL-10, other eight collectins have been identified, including mannose-binding lectin (MBL), surfactant proteins A and D (SP-A and SP-D), collectin placenta 1 (CL-12), conglutinin, collectins of 43kDA and 46 kDa, and collectin-11. These proteins are highly conserved in evolution, with the same structural characteristics as collagen and the same functional properties as lectins.

CL-10 is one of the most recently discovered collectins. It is primary expressed in the liver and placenta. It involves a series of steps of the lectin complement pathway which plays an important role in the migration of cells to form organs and systems of the body during development before birth. Besides, CL-10 appears to be particularly important in the regulation of immune responses. CL-11 and CL-10 have been shown to form hetero-oligomers which circulate in the serum and binds to mannose-binding lectin (MBL)-associated serine proteases (MASPs), involved in the complement activation in a MASP-2-dependent fashion. CL-10 has also revealed to bind to carbohydrate antigens on microorganisms such as mannose, fucose, and galactose with high affinity, facilitating the complement activation against foreigners.