Limited effect of recombinant human mannose-binding lectin on the infection of novel influenza A (H7N9) virus in vitro

Mannose-binding lectin (MBL) is a circulating protein that acts as a soluble pattern recognition molecule of the innate immunity. It binds to carbohydrate patterns on the surface of pathogens or of altered self-cells, with activation of the lectin pathway of the complement system. Recent evidence indicates that MBL contributes to the pathophysiology of ischemia-reperfusion injury and other conditions. Thus, MBL inhibitors offer promising therapeutic strategies, since they prevent the interaction of MBL with its target sugar arrays. We developed and characterized a novel assay based on surface plasmon resonance for in vitro screening of these compounds, which may be useful before the more expensive and time-consuming in vivo studies. The assay measures the inhibitor’s ability to interfere with the binding of murine MBL-A or MBL-C, or of human recombinant MBL, to mannose residues immobilized on the sensor chip surface. We have applied the assay to measure the IC50 of synthetic glycodendrimers, two of them with neuroprotective properties in animal models of MBL-mediated injuries.

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Mannose-Binding Lectin in Severe Acute Respiratory Syndrome Coronavirus Infection

The Journal of Infectious Diseases ◽

10.1086/429631 ◽

2005 ◽

Vol 191 (10) ◽

pp. 1697-1704 ◽

Cited By ~ 133

Author(s):

W. K. Eddie Ip ◽

Kwok Hung Chan ◽

Helen K. W. Law ◽

Gloria H. W. Tso ◽

Eric K. P. Kong ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Serum Levels ◽

Mannose Binding Lectin ◽

In Vitro Assays ◽

Calcium Dependent ◽

Control Subjects ◽

Mannose Binding ◽

Carbohydrate Recognition Domains ◽

Binding Lectin

Abstract Little is known about the innate immune response to severe acute respiratory syndrome (SARS) coronavirus (CoV) infection. Mannose-binding lectin (MBL), a key molecule in innate immunity, functions as an ante-antibody before the specific antibody response. Here, we describe a case-control study that included 569 patients with SARS and 1188 control subjects and used in vitro assays to investigate the role that MBL plays in SARS-CoV infection. The distribution of MBL gene polymorphisms was significantly different between patients with SARS and control subjects, with a higher frequency of haplotypes associated with low or deficient serum levels of MBL in patients with SARS than in control subjects. Serum levels of MBL were also significantly lower in patients with SARS than in control subjects. There was, however, no association between MBL genotypes, which are associated with low or deficient serum levels of MBL, and mortality related to SARS. MBL could bind SARS-CoV in a dose- and calcium-dependent and mannan-inhibitable fashion in vitro, suggesting that binding is through the carbohydrate recognition domains of MBL. Furthermore, deposition of complement C4 on SARS-CoV was enhanced by MBL. Inhibition of the infectivity of SARS-CoV by MBL in fetal rhesus kidney cells (FRhK-4) was also observed. These results suggest that MBL contributes to the first-line host defense against SARS-CoV and that MBL deficiency is a susceptibility factor for acquisition of SARS

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Antimicrobial activity of mannose binding lectin in grass carp (Ctenopharyngodon idella) in vivo and in vitro

Fish & Shellfish Immunology ◽

10.1016/j.fsi.2019.12.088 ◽

2020 ◽

Vol 98 ◽

pp. 25-33

Author(s):

Lei Liu ◽

Yunfei Dang

Keyword(s):

Antimicrobial Activity ◽

Grass Carp ◽

Mannose Binding Lectin ◽

Ctenopharyngodon Idella ◽

Mannose Binding ◽

Grass Carp Ctenopharyngodon Idella ◽

Binding Lectin

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Mannose-binding Lectin-deficient Mice Are Susceptible to Infection with Staphylococcus aureus

Journal of Experimental Medicine ◽

10.1084/jem.20032207 ◽

2004 ◽

Vol 199 (10) ◽

pp. 1379-1390 ◽

Cited By ~ 207

Author(s):

Lei Shi ◽

Kazue Takahashi ◽

Joseph Dundee ◽

Sarit Shahroor-Karni ◽

Steffen Thiel ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Susceptibility Gene ◽

Humoral Response ◽

Mannose Binding Lectin ◽

Host Responses ◽

Mannose Binding ◽

Disease Susceptibility Gene ◽

Binding Lectin

Gram-positive organisms like Staphylococcus aureus are a major cause of morbidity and mortality worldwide. Humoral response molecules together with phagocytes play a role in host responses to S. aureus. The mannose-binding lectin (MBL, also known as mannose-binding protein) is an oligomeric serum molecule that recognizes carbohydrates decorating a broad range of infectious agents including S. aureus. Circumstantial evidence in vitro and in vivo suggests that MBL plays a key role in first line host defense. We tested this contention directly in vivo by generating mice that were devoid of all MBL activity. We found that 100% of MBL-null mice died 48 h after exposure to an intravenous inoculation of S. aureus compared with 45% mortality in wild-type mice. Furthermore, we demonstrated that neutrophils and MBL are required to limit intraperitoneal infection with S. aureus. Our study provides direct evidence that MBL plays a key role in restricting the complications associated with S. aureus infection in mice and raises the idea that the MBL gene may act as a disease susceptibility gene against staphylococci infections in humans.

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A novel mannose-binding lectin from Liparis nervosa with anti-fungal and anti-tumor activities

Acta Biochimica et Biophysica Sinica ◽

10.1093/abbs/gmaa090 ◽

2020 ◽

Vol 52 (10) ◽

pp. 1081-1092

Author(s):

Na Jiang ◽

Yuqing Wang ◽

Jing Zhou ◽

Ruxiao Zheng ◽

Xiao Yuan ◽

...

Keyword(s):

Gel Filtration ◽

Sclerotium Rolfsii ◽

Exchange Chromatography ◽

Mannose Binding Lectin ◽

Carbohydrate Binding ◽

Plant Lectins ◽

Mannose Binding ◽

Anti Fungal ◽

Binding Lectin

Abstract Plant lectins are carbohydrate-binding proteins with nonimmune origin, which can reversibly bind with carbohydrates, agglutinate cells, and precipitate polysaccharides and glycoconjugates. Plant lectins have attracted much attention for their anti-virus, anti-proliferation, and pro-apoptosis properties. Thus the exploration of new lectins has received special attention. Here we purified a mannose-binding lectin from the rhizomes of Liparis nervosa by ion exchange chromatography on DEAE-Sepharose, affinity chromatography on Mannose-Sepharose 4B, and gel filtration chromatography on Sephacryl S-100. The purified L. nervosa lectin (LNL) was identified to be a monomeric protein with a molecular mass of 13 kDa. LNL exhibited hemagglutinating activity towards rabbit erythrocytes, and its activity could be strongly inhibited by D-mannose, N-acetyl glucosamine and thyroglobulin. In vitro experiments showed that LNL exhibited a comparable anti-fungal activity against Piricularia oryzae (Cavara), Bipolaris maydis, Fusarium graminearum, and Sclerotium rolfsii, and anti-proliferation activity against tumor cells by inducing apoptosis. The full-length cDNA sequence of LNL is 715 bp in length and contains a 525 bp open reading frame (ORF) encoding a 110-residue mature protein. It was predicted to have three mannose-binding conserved motifs ‘QXDXNXVXY’. The binding pattern of LNL was further revealed by homology modeling and molecular docking. We demonstrated that LNL is not only a potential therapeutic candidate against tumor but also a new anti-fungal agent.

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