What is the function of mannose binding protein?
Mannose-binding lectin plays an important role in the body’s immune response by attaching to foreign invaders such as bacteria, viruses, or yeast and turning on (activating) the complement system .
What does high mannose binding lectin mean?
A role for mannose binding lectin (MBL) in autoimmune diseases has been demonstrated earlier and elevated level of MBL has been shown in systemic lupus erythematosus (SLE) patients. In the current study, we investigated MBL as a potential biomarker for disease activity in SLE.
What activates the mannose binding lectin pathway?
Activation of the lectin pathway occurs through the binding of the complex of mannose-binding lectin (MBL), CL-K1 or ficolins, and MBL-associated serine proteases 1 and 2 (MASP-1 and MASP-2, respectively) to various carbohydrates or acetylated residues on the surface of pathogens (PAMP, pathogen-associated molecular …
How does mannose lead to complement activation?
Complement activation is initiated when complexes comprising mannose-binding lectin (MBL) or serum ficolins and MBL-associated serine protease-2 (MASP-2) bind to pathogens. A major goal in complement research is to understand the molecular events that trigger complement activation.
What does mannose-binding lectin recognize?
MBL recognizes specific carbohydrates such as d-mannose, l-fucose and N-acetylglucosamine that are represented on the surface of a wide variety of infectious agents (Figure 1b) [1]. Pathogens targeted by MBL include certain Gram-positive and Gram-negative bacteria, yeast, parasites and viruses [9].
Where is mannose-binding lectin found?
It is produced in the liver as a response to infection, and is part of many other factors termed acute phase proteins. Expression and function in other organs were also suggested.
What is normal range for mannose binding lectin?
Normal serum levels of MBL range from 800 to 1000 ng/ml in healthy Caucasians, however, wide variations can occur due to point mutations in codons 52, 54 and 57 of exon 1 and/or in the promotor region of the MBL gene [3].
Is MBL deficiency an autoimmune disease?
Interestingly, absence or extremely low concentration of serum MBL (MBL deficiency) seems to be a risk factor for occurrence of autoimmune diseases, in particular systemic lupus erythematosus. In addition, individuals with MBL deficiency are at risk of infection when in immunocompromised conditions.
What does the lectin pathway do?
The lectin pathway plays a major protective role during the vulnerability window experienced by infants between decay of maternal antibody and establishment of an effective adaptive immune system. Activation of the complement via the lectin pathway occurs when the proenzyme forms of MASPs are activated.
What does the lectin pathway lead to?
The lectin pathway or lectin complement pathway is a type of cascade reaction in the complement system, similar in structure to the classical complement pathway, in that, after activation, it proceeds through the action of C4 and C2 to produce activated complement proteins further down the cascade.
Is mannose-binding lectin a complement?
Mannan-binding lectin, also called mannose-binding protein, is a protein belonging to the collectin family that is produced by the liver and can initiate the complement cascade by binding to pathogen surfaces.
How is lectin complement pathway activated?
The lectin pathway of the complement is activated when MBL binds to hexoses with carbon 3 and 4 OH groups such as N-acetyl-d-glucosamine, glucose, fucose, and mannose. These sugars are expressed as repetitive O-polysaccharide structures on surfaces of bacteria, yeast, parasites, mycobacteria, and certain viruses.
Which is a protein that binds to mannose?
In man, these proteins include serum MBL, lung surfactant protein A (SP-A) and lung surfactant protein D (SP-D). MBL binds to a range of sugars including N-acetyl-D-glucosamine, mannose, N-acetyl-mannosamine, fucose and glucose.
What happens to mannose binding lectin ( MBL ) deficiency?
Mannose-binding lectin (MBL) deficiency results in a decreased amount of a specific protein (mannan-binding protein) involved in the immune system.
What kind of sugar does MBL bind to?
MBL binds to a range of sugars including N-acetyl-D-glucosamine, mannose, N-acetyl-mannosamine, fucose and glucose. This permits the protein to interact with a wide selection of viruses, bacteria, yeasts, fungi and protozoa decorated with such sugars.