Structure, function, molecular genetics, disease associations and therapeutic potential of mannose binding lectin: review

Abstract

Mannose binding lectin (MBL) which is a collagen like serum protein and primarily synthesized by the liver is a significant component of natural immune response. MBL molecule provides phagocytosis of those microorganisms by macrophages or activates the lectin pathway of complement system via C3 convertase by binding on sugar groups on the surfaces of multifarious microorganisms. The MBL2 gene is located on chromosome 10 at position 10q11.2-q21 and consists of four exons and three introns. Three genetic variations named as allel B (codon 54, GGC > GAC, Gly > Asp), allel C (codon 57, GGA > GAA, Gly > Glu) and allel D (codon 52, GCT > TGT, Arg > Cys) and affecting the serum levels and trimerization of MBL protein were detected on the first exon of MBL2 gene. An association was shown between MBL2 gene codon variants or low MBL serum levels and bacterial, viral and fungal infections or autoimmunity development. An association was also detected between high MBL serum levels and renal graft rejection, diabetic nephropathy and inflammatory diseases. In this review, relationships between MBL and diseases and therapeutic potential of the molecule were summarized along with the molecular structure, function and genetics of MBL.