scholarly journals Mannose-Binding Lectin Binds to Amyloid Protein and Modulates Inflammation

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Mykol Larvie ◽  
Timothy Shoup ◽  
Wei-Chuan Chang ◽  
Lorencia Chigweshe ◽  
Kevan Hartshorn ◽  
...  
Keyword(s):  
Mannose Receptor ◽  
Tissue Homeostasis ◽  
Mannose Binding Lectin ◽  
Binding Characteristics ◽  
Calcium Dependent ◽  
Rich Domain ◽  
Mannose Binding ◽  
Carbohydrate Ligands ◽  
Binding Lectin ◽  
Cysteine Rich Domain

Mannose-binding lectin (MBL), a soluble factor of the innate immune system, is a pattern recognition molecule with a number of known ligands, including viruses, bacteria, and molecules from abnormal self tissues. In addition to its role in immunity, MBL also functions in the maintenance of tissue homeostasis. We present evidence here that MBL binds to amyloidβpeptides. MBL binding to other known carbohydrate ligands is calcium-dependent and has been attributed to the carbohydrate-recognition domain, a common feature of other C-type lectins. In contrast, we find that the features of MBL binding to Aβare more similar to the reported binding characteristics of the cysteine-rich domain of the unrelated mannose receptor and therefore may involve the MBL cysteine-rich domain. Differences in MBL ligand binding may contribute to modulation of inflammatory response and may correlate with the function of MBL in processes such as coagulation and tissue homeostasis.

scholarly journals Mannose-Binding Lectin in Severe Acute Respiratory Syndrome Coronavirus Infection

2005 ◽  
Vol 191 (10) ◽  
pp. 1697-1704 ◽  
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

scholarly journals Mannose-Binding Lectin Is a Disease Modifier in Clinical Malaria and May Function as Opsonin for Plasmodium falciparum- Infected Erythrocytes

2003 ◽  
Vol 71 (9) ◽  
pp. 5245-5253 ◽  
Author(s):  
Peter Garred ◽  
Morten A. Nielsen ◽  
Jørgen A.L. Kurtzhals ◽  
Rajneesh Malhotra ◽  
Hans O. Madsen ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Stress Protein ◽  
Clinical Malaria ◽  
Mannose Binding Lectin ◽  
Calcium Dependent ◽  
Glucose Levels ◽  
Mannose Binding ◽  
Disease Modifier ◽  
Variant Alleles ◽  
Binding Lectin

ABSTRACT Variant alleles in the mannose-binding lectin (MBL) gene (mbl2) causing low levels of functional MBL are associated with susceptibility to different infections and are common in areas where malaria is endemic. Therefore, we investigated whether MBL variant alleles in 551 children from Ghana were associated with the occurrence and outcome parameters of Plasmodium falciparum malaria and asked whether MBL may function as an opsonin for P. falciparum. No difference in MBL genotype frequency was observed between infected and noninfected children or between children with cerebral malaria and/or severe malarial anemia and children with uncomplicated malaria. However, patients with complicated malaria who were homozygous for MBL variant alleles had significantly higher parasite counts and lower blood glucose levels than their MBL-competent counterparts. Distinct calcium-dependent binding of MBL to the membrane of P. falciparum-infected erythrocytes, which could be inhibited by mannose, was observed. Further characterization revealed that MBL reacted with a P. falciparum glycoprotein identical to the 78-kDa glucose-regulated stress protein of P. falciparum. MBL seems to be a disease modifier in clinical malaria and to function as an opsonin for erythrocytes invaded by P. falciparum and may thus be involved in sequestration of the parasite, which in turn may explain the association between homozygosity for MBL variant alleles and high parasite counts.

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