scholarly journals Components of the Lectin Pathway of Complement in Haematologic Malignancies

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1792
Author(s):  
Maciej Cedzyński ◽  
Anna S. Świerzko
Keyword(s):  
Serine Proteases ◽  
Proteolytic Enzymes ◽  
Alternative Pathway ◽  
Mannose Binding Lectin ◽  
Lectin Pathway ◽  
Classical Pathway ◽  
Mannose Binding ◽  
Molecular Patterns ◽  
Binding Lectin ◽  
Haematologic Malignancies

The complement system is activated cascadically via three distinct major routes: classical pathway (CP), alternative pathway (AP) or lectin pathway (LP). The unique factors associated with the latter are collectins (mannose-binding lectin, collectin-10, collectin-11), ficolins (ficolin-1, ficolin-2, ficolin-3) and proteins of the mannose-binding lectin-associated serine protease (MASP) family (MASP-1, MASP-2, MASP-3, MAp19, MAp44). Collectins and ficolins are both pattern-recognising molecules (PRM), reactive against pathogen-associated molecular patterns (PAMP) or danger-associated molecular patterns (DAMP). The MASP family proteins were first discovered as complexes with mannose-binding lectin (MBL) and therefore named MBL-associated serine proteases, but later, they were found to interact with ficolins, and later still, collectin-10 and collectin-11. As well as proteolytic enzymes (MASP-1, MASP-2, MASP-3), the group includes non-enzymatic factors (MAp19, MAp44). In this review, the association-specific factors of the lectin pathway with haematologic malignancies and related infections are discussed.

scholarly journals Impact of Mannose-Binding Lectin Deficiency on Radiocontrast-Induced Renal Dysfunction

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Michael Osthoff ◽  
Marten Trendelenburg
Keyword(s):  
Endothelial Dysfunction ◽  
Renal Dysfunction ◽  
Serine Proteases ◽  
Vascular Endothelial Cells ◽  
Ischemia Reperfusion ◽  
Mannose Binding Lectin ◽  
Lectin Pathway ◽  
Increased Risk ◽  
Mannose Binding ◽  
Binding Lectin

Contrast-induced nephropathy (CIN) is the third leading cause of acute renal failure in hospitalized patients. Endothelial dysfunction, renal medullary ischemia, and tubular toxicity are regarded as the most important factors in the pathogenesis of CIN. Mannose-binding lectin (MBL), a pattern recognition protein of the lectin pathway of complement, has been found to aggravate and mediate tissue damage during experimental renal ischemia/reperfusion (I/R) injury which was alleviated by inhibition with C1 inhibitor, a potent MBL, and lectin pathway inhibitor. In this paper, we highlight the potential role of MBL in the pathogenesis of human CIN. In experimental I/R models, MBL was previously found to induce tubular cell death independent of the complement system. In addition, after binding to vascular endothelial cells, MBL and its associated serine proteases were able to trigger a proinflammatory reaction and contribute to endothelial dysfunction. In humans, urinary MBL was increased after administration of contrast media and in individuals with CIN. Moreover, individuals with normal/high MBL levels were at increased risk to develop radiocontrast-induced renal dysfunction. Hence, MBL and the lectin pathway seem to be a promising target given that a licensed, powerful, human recombinant inhibitor exits to be added to the scarce armamentarium currently available for prophylaxis of CIN.

scholarly journals Complement Alternative and Mannose-Binding Lectin Pathway Activation Is Associated With COVID-19 Mortality

2021 ◽  
Vol 12 ◽  
Author(s):  
Federica Defendi ◽  
Corentin Leroy ◽  
Olivier Epaulard ◽  
Giovanna Clavarino ◽  
Antoine Vilotitch ◽  
...  
Keyword(s):  
Mannose Binding Lectin ◽  
University Hospital ◽  
Lectin Pathway ◽  
Study Cohort ◽  
Classical Pathway ◽  
Factor B ◽  
Immune Correlates ◽  
Mannose Binding ◽  
Activation Pathways ◽  
Binding Lectin

BackgroundThe SARS-CoV-2 infection triggers excessive immune response resulting in increased levels of pro-inflammatory cytokines, endothelial injury, and intravascular coagulopathy. The complement system (CS) activation participates to this hyperinflammatory response. However, it is still unclear which activation pathways (classical, alternative, or lectin pathway) pilots the effector mechanisms that contribute to critical illness. To better understand the immune correlates of disease severity, we performed an analysis of CS activation pathways and components in samples collected from COVID-19 patients hospitalized in Grenoble Alpes University Hospital between 1 and 30 April 2020 and of their relationship with the clinical outcomes.MethodsWe conducted a retrospective, single-center study cohort in 74 hospitalized patients with RT-PCR-proven COVID-19. The functional activities of classical, alternative, and mannose-binding lectin (MBL) pathways and the antigenic levels of the individual components C1q, C4, C3, C5, Factor B, and MBL were measured in patients’ samples during hospital admission. Hierarchical clustering with the Ward method was performed in order to identify clusters of patients with similar characteristics of complement markers. Age was included in the model. Then, the clusters were compared with the patient clinical features: rate of intensive care unit (ICU) admission, corticoid treatment, oxygen requirement, and mortality.ResultsFour clusters were identified according to complement parameters. Among them, two clusters revealed remarkable profiles: in one cluster (n = 15), patients exhibited activation of alternative and lectin pathways and low antigenic levels of MBL, C4, C3, Factor B, and C5 compared to all the other clusters; this cluster had the higher proportion of patients who died (27%) and required oxygen support (80%) or ICU care (53%). In contrast, the second cluster (n = 19) presented inflammatory profile with high classical pathway activity and antigenic levels of complement components; a low proportion of patients required ICU care (26%) and no patient died in this group.ConclusionThese findings argue in favor of prominent activation of the alternative and MBL complement pathways in severe COVID-19, but the spectrum of complement involvement seems to be heterogeneous requiring larger studies.

scholarly journals Fasciola hepatica is refractory to complement killing by preventing attachment of mannose binding lectin (MBL) and inhibiting MBL-associated serine proteases (MASPs) with serpins

2022 ◽  
Vol 18 (1) ◽  
pp. e1010226
Author(s):  
Carolina De Marco Verissimo ◽  
Heather L. Jewhurst ◽  
József Dobó ◽  
Péter Gál ◽  
John P. Dalton ◽  
...  
Keyword(s):  
Serine Proteases ◽  
Fasciola Hepatica ◽  
Membrane Attack Complex ◽  
Mannose Binding Lectin ◽  
Helminth Parasite ◽  
Lectin Pathway ◽  
Mannose Binding ◽  
Carbohydrate Arrays ◽  
Infectious Stage ◽  
Binding Lectin

The complement system is a first-line innate host immune defence against invading pathogens. It is activated via three pathways, termed Classical, Lectin and Alternative, which are mediated by antibodies, carbohydrate arrays or microbial liposaccharides, respectively. The three complement pathways converge in the formation of C3-convertase followed by the assembly of a lethal pore-like structure, the membrane attack complex (MAC), on the pathogen surface. We found that the infectious stage of the helminth parasite Fasciola hepatica, the newly excysted juvenile (NEJ), is resistant to the damaging effects of complement. Despite being coated with mannosylated proteins, the main initiator of the Lectin pathway, the mannose binding lectin (MBL), does not bind to the surface of live NEJ. In addition, we found that recombinantly expressed serine protease inhibitors secreted by NEJ (rFhSrp1 and rFhSrp2) selectively prevent activation of the complement via the Lectin pathway. Our experiments demonstrate that rFhSrp1 and rFhSrp2 inhibit native and recombinant MBL-associated serine proteases (MASPs), impairing the primary step that mediates C3b and C4b deposition on the NEJ surface. Indeed, immunofluorescence studies show that MBL, C3b, C4b or MAC are not deposited on the surface of NEJ incubated in normal human serum. Taken together, our findings uncover new means by which a helminth parasite prevents the activation of the Lectin complement pathway to become refractory to killing via this host response, in spite of presenting an assortment of glycans on their surface.

scholarly journals Pathological Scenario with the Mannose-Binding Lectin in Patients with IgA Nephropathy

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Isao Ohsawa ◽  
Masaya Ishii ◽  
Hiroyuki Ohi ◽  
Yasuhiko Tomino
Keyword(s):  
Iga Nephropathy ◽  
Clinical Presentation ◽  
Alternative Pathway ◽  
Mannose Binding Lectin ◽  
Secretory Iga ◽  
Lectin Pathway ◽  
Additional Mechanism ◽  
Mannose Binding ◽  
Binding Lectin ◽  
Mbl Deficiency

A deeper understanding of the mechanism of complement activation may help to elucidate the pathogenesis of IgA nephropathy (IgAN). Traditionally, the activation of an alternative pathway (AP) has been recognized as an enhancer mechanism of glomerular damage. This paper documents contemporary information concerning the possible pathological mechanisms of the lectin pathway (LP) in the circulation and in the glomerulus. The circulating initiator of LP activation is not fully understood. However, ligands for mannose-binding lectin (MBL) which are among the starter molecules of the LP are aberrant glycosylated molecules-containing immune complex. Recent reports have focused onN-glycans on secretory IgA as a candidate ligand. Mesangial deposits of MBL are seen in 25% of patients with IgAN. Mesangial deposits of MBL and C4 and/or C4 breakdown products are implicated as markers for disease progression of IgAN. On the other hand, patients with MBL deficiency tend to show better clinical presentation and lower levels of urinary protein and serum creatinine than MBL-sufficient patients. It is now recognized that involvement of AP and LP constitutes an additional mechanism for explaining the progression of IgAN.

scholarly journals Mechanisms of mannose-binding lectin-associated serine proteases-1/3 activation of the alternative pathway of complement

2011 ◽  
Vol 49 (1-2) ◽  
pp. 281-289 ◽  
Author(s):  
Nirmal K. Banda ◽  
Minoru Takahashi ◽  
Kazue Takahashi ◽  
Gregory L. Stahl ◽  
Stephanie Hyatt ◽  
...  
Keyword(s):  
Serine Proteases ◽  
Alternative Pathway ◽  
Mannose Binding Lectin ◽  
Mannose Binding ◽  
Alternative Pathway Of Complement ◽  
Binding Lectin

scholarly journals Essential role of Mannose-binding lectin-associated serine protease-1 in activation of the complement factor D

2009 ◽  
Vol 207 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Minoru Takahashi ◽  
Yumi Ishida ◽  
Daisuke Iwaki ◽  
Kazuko Kanno ◽  
Toshiyuki Suzuki ◽  
...  
Keyword(s):  
Serine Protease ◽  
Alternative Pathway ◽  
Active Form ◽  
Mannose Binding Lectin ◽  
Activation Mechanism ◽  
Lectin Pathway ◽  
Complement Factor ◽  
Mannose Binding ◽  
Activation Peptide ◽  
Binding Lectin

The complement system is an essential component of innate immunity, participating in the pathogenesis of inflammatory diseases and in host defense. In the lectin complement pathway, mannose-binding lectin (MBL) and ficolins act as recognition molecules, and MBL-associated serine protease (MASP) is a key enzyme; MASP-2 is responsible for the lectin pathway activation. The function of other serine proteases (MASP-1 and MASP-3) is still obscure. In this study, we generated a MASP-1– and MASP-3–deficient mouse model (Masp1/3−/−) and found that no activation of the alternative pathway was observed in Masp1/3−/− serum. Mass spectrometric analysis revealed that circulating complement factor D (Df) in Masp1/3−/− mice is a zymogen (pro-Df) with the activation peptide QPRGR at its N terminus. These results suggested that Masp1/3−/− mice failed to convert pro-Df to its active form, whereas it was generally accepted that the activation peptide of pro-Df is removed during its secretion and factor D constitutively exists in an active form in the circulation. Furthermore, recombinant MASP-1 converted pro-Df to the active form in vitro, although the activation mechanism of pro-Df by MASP-1 is still unclear. Thus, it is clear that MASP-1 is an essential protease of both the lectin and alternative complement pathways.

scholarly journals Polymorphisms in the Mannose-Binding Lectin Gene are Associated with Defective Mannose-Binding Lectin Functional Activity in Crohn’s Disease Patients

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Laura Choteau ◽  
Francis Vasseur ◽  
Frederic Lepretre ◽  
Martin Figeac ◽  
Corine Gower-Rousseau ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Functional Activity ◽  
Serine Proteases ◽  
Mannose Binding Lectin ◽  
Lectin Pathway ◽  
Disease Phenotype ◽  
Mannose Binding ◽  
Antibody Levels ◽  
Binding Lectin

Abstract Mannose-binding lectin, together with mannose-associated serine proteases, activates the lectin pathway of the complement system and subsequent inflammatory mechanisms. An association between mannose-binding lectin deficiency and anti-Saccharomyces cerevisiae antibody levels is observed in Crohn’s disease and this deficiency is frequently associated with a severe Crohn’s disease phenotype. In the present study, we assessed the relationship between serum concentrations of mannose-binding lectin, mannose-binding lectin functional activity, MBL2 and NOD2 polymorphisms, anti-S. cerevisiae antibody levels and clinical Crohn’s disease phenotype in 69 Crohn’s disease patients and 30 age- and sex-matched healthy controls. The results show that the MBL2 variant rs5030737 at codon 52 was associated with a low level of mannose-binding lectin and impaired mannose-binding lectin–mannose-associated serine protease (MBL-MASP) functional activity in Crohn’s disease patients. This MBL2 variant was also associated with a higher level of anti-S. cerevisiae antibodies. In addition, the NOD2 variant rs2066844, which is associated with susceptibility to Crohn’s disease, was significantly correlated with an impairment in MBL-MASP functional activity. These results provide evidence that Crohn’s disease patients have an impairment in MBL-MASP functional activity and that this defect is associated with MBL2 and NOD2 variants.

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