Mannose-binding lectin protein 2 (MBL2)

Mannose-binding lectin protein 2 (MBL2) is a critical pattern-recognition molecule of the innate immune system, primarily synthesized in the liver and secreted into the blood. It belongs to the collectin family and functions by recognizing and binding to specific carbohydrate patterns, such as mannose and N-acetylglucosamine, found on the surfaces of various pathogens including bacteria, viruses, and fungi (UniProt P11226; MedlinePlus). Upon binding, MBL2 activates the lectin pathway of the complement system through its association with MBL-associated serine proteases (MASPs), which leads to the opsonization and direct lysis of the invading microorganism (PubMed: 14568388). Genetic polymorphisms in the MBL2 gene are highly prevalent and often result in MBL deficiency, which significantly increases susceptibility to recurrent infections, particularly in children and immunocompromised patients (NIH: 154545). Conversely, elevated MBL activity has been linked to tissue injury in conditions like traumatic brain injury and ischemia-reperfusion, making it a target for both replacement therapy and inhibitory strategies (PubMed: 34841234). Current therapeutic approaches include the use of recombinant human MBL (rhMBL) for deficiency and experimental glycomimetics like Polyman9 to modulate its inflammatory effects.

Other names

Mannose-binding protein CMannan-binding proteinMannan-binding lectinCollectin-1COLEC1MBP-CMBP1MBLHSMBPCMBL2D

Drugs targeting MBL2 primarily act through replacement therapy to restore innate immune function in deficient individuals or through competitive inhibition (using glycomimetics) to prevent excessive complement activation and subsequent tissue damage in inflammatory conditions.