Interactions of Ficolin and Mannose-Binding Lectin with Fibrinogen/Fibrin Augment the Lectin Complement Pathway

Abstract

Ficolin and mannose-binding lectin (MBL) are animal lectins that are involved in innate immunity by initiating the lectin complement pathway. Here, we report that interactions between these lectins and fibrinogen/fibrin augment the lectin pathway. An ELISA revealed that recombinant mouse ficolin A (rFcnA), rMBL-A and rMBL-C bind to fibrinogen in a dose-dependent manner. Affinity Western blotting showed that these lectins bind to the Aα- and Bβ-chains of fibrinogen and the α- and β-chains of fibrin, but not to the γ-chain, and that rMBL-A and rMBL-C preferentially bind to the α- and β-chains. The C4 deposition activity on Fbg-coated plates was observed by using mouse serum, and the deposition on GlcNAc-coated plates was enhanced by fibrinogen supplementation and further enhanced by the addition of thrombin. Similar effects of fibrinogen and fibrin were observed in the bindings of these lectins to a Gram-positive pathogen, Staphylococcus aureus, and in the subsequent C3 deposition on the bacteria. In particular, the lectin pathway, through MBLs, seemed to synchronize with blood coagulation. Therefore, it is suggested that the lectin pathway collaborates with the coagulation system in the first-line host defense against pathogens under conditions such as injury and inflammation.

Antiinflammatory Effects of Budesonide in Human Fetal Lung

“…Ficolin (FCN2), which is induced 28-fold, may activate the lectin/complement pathway and may enhance innate immunity in the lung (37). IL6R, a component of the IL6 receptor, is induced but appears to be proinflammatory as a mediator of IL6 signaling.…”

Mannose-Binding Lectin Promotes Local Microvascular Thrombosis After Transient Brain Ischemia in Mice

“…17 The complement and the coagulation systems crossinteract at several molecular steps. 21,22 Proteins of the lectin pathway can induce thrombus formation through thrombin activation, [23][24][25][26][27] thus exacerbating brain damage after ischemia/ reperfusion. [28][29][30] In this study, we evaluated the role of MBL in thrombus formation and whether this interaction is involved in brain damage after ischemia/reperfusion in mice.…”

Finding immune gene expression differences induced by marine bacterial pathogens in the Deep-sea hydrothermal vent mussel <i>Bathymodiolus azoricus</i>

“…Lectins constitute a group of sugar-binding proteins that recognise specific carbohydrate structures allowing agglutination of foreign cells and the stimulation of phagocytosis (Endo et al, 2010;Kilpatrick, 2002) in innate immunity of bivalves (Bulgakov et al, 2004). However, the Rhamnose-binding lectin and the Immune lectin receptor 2, two lectin-like immune molecules whose expression profiles differed distinctively between 12 h and 24 h infection time, seem to suggest that infections carried out with Vibrio are yet to induce Rhamnose-binding lectin transcript levels above seawater-incubation experiments ( Fig.…”