Abstract
Mannose binding lectin (MBL) is a serum collagenous C-type lectin that plays an important role in the innate immune protection against pathogens. Previously, human and mouse studies have demonstrated that MBL binds a broad range of pathogens that results in their neutralization through agglutination, enhanced phagocytosis, and/or complement activation via the lectin pathway. The role of MBL in chicken is not well understood although the MBL concentration in serum seems to correlate with protection against infections. To investigate the role of MBL in chicken further, recombinant chicken MBL (RcMBL) was produced in HeLa R19 cells and purified using mannan affinity chromatography followed by gel filtration. RcMBL was shown to be structurally and functionally similar to native chicken MBL (NcMBL) isolated from serum. RcMBL is expressed as an oligomeric protein (mixture of trimers and oligomerized trimers) with a monomeric mass of 26kDa as determined by mass spectrometry, corresponding to the predicted mass. Glycan array analysis indicated that RcMBL bound most strongly to high-mannose glycans but also glycans with terminal fucose and GlcNac residues. The biological activity of RcMBL was demonstrated via its capacity to agglutinate Salmonella Typhimurium and to inhibit the hemagglutination activity of influenza A virus. The production of a structurally well-characterized and functionally active RcMBL will facilitate detailed studies into the protective role of MBL in innate defense against pathogens in chicken and other avian species.
Highlights
Mannose binding lectin (MBL) is a serum collectin, which plays an important role in the innate immune response
Collectin-mediated innate immune responses play an important role in the first line defense against infections as illustrated by numerous studies in humans and other mammalian species
Not much is known about the specific role of these collagenous C-type lectins, including MBL, the most well-characterized serum collectin
Summary
Mannose binding lectin (MBL) is a serum collectin (collagenous C-type lectin), which plays an important role in the innate immune response. Like all members of the collectin family, MBL binds and recognizes a wide range of pathogens, including fungi, bacteria, viruses and parasites, leading to agglutination and neutralization of these microorganisms. The polypeptide domain organization of MBL is shared by all members of the collectin family and is characterized by a short N-terminal cysteine-rich region, a collagen-like region containing Gly-Xaa-Yaa repeats, and an ␣-helical coiled-coil neck region followed by a carbohydrate recognition domain (CRD, or lectin domain). Trimerization of MBL facilitates the formation of the collagen triple helix and generates a cluster of three adjacent CRDs that makes MBL, like all collectins, a “pattern recognition molecule”, having the ability to interact with specific pathogen-associated molecular patterns (PAMPs). Human MBL is assembled into various degrees of multimerization, ranging from dimers to hexamers of trimeric subunits that resemble a “bouquet of tulips”, as visualized by electron microscopy (Jensenius et al, 2009; Lu et al, 1990)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
