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Host Defense I: Non-specific Immunity
Published in Constantin A. Bona, Francisco A. Bonilla, Textbook of Immunology, 2019
Constantin A. Bona, Francisco A. Bonilla
The β2 integrins are also heterodimers whose a chains are different forms of CD11, and β chain is CD18. LFA-1 (CD11a/CD18) interacts with ICAM-1 (CD54) and ICAM-2 (CD102). This interaction is important for granulocyte function, as well as intercellular interactions important in T and B cell activation. CD11 b/CD18 and CD11 c/CD18 are also known as complement receptors CR3 and CR4, respectively. These bind the iC3b component of complement and assist in opsonization (see above). CD11b/CD18 also binds ICAM-1, and coagulation factor X. CD18 by itself binds to bacterial lipopolysaccharide.
Pathways for Induction and The Nature of Macrophage Procoagulant Activity
Published in Gary A. Levy, Edward H. Cole, Procoagulant Activity in Health and Disease, 2019
Robert J. Fingerote, Gary A. Levy
Altieri et al. have shown that, in the absence of expression of TF, ADP-stimulated monocytes can initiate coagulation by the binding of coagulation factor X to the surface-adhesive receptor Mac-1 (CD11b/CD18).87 Locally, Mac-1-concentrated factor X is rapidly proteolytically cleaved to an active protease, resulting in the formation of thrombin and the procoagulant response. Furthermore, this same group has demonstrated that Mac-1 functions as a receptor for fibrinogen.88 As well, monocytes and monocyte-like cells have been shown to synthesize and express an additional receptor which bears similarity to factor V/factor Va. This receptor then binds factor Xa, resulting in the organization of a functional prothrombinase complex. Thus, the simultaneous membrane coexpression of a factor X receptor (Mac-1) and a factor Xa receptor (factor V/Va-like receptor) is consistent with an additional sequential receptor cascade for coordinated molecular assembly of coagulation proteins on monocytes/macrophages.
Pharmacological Intervention on the Host’s Hemostatic System and Experimental Metastases: Role of Cancer Cell Activities
Published in László Muszbek, Hemostasis and Cancer, 2019
A number of studies we have performed on the 3LL and other murine models (B16 melanoma, JW sarcoma, MFS6 fibrosarcoma2,7 has led us to propose that (1) warfarin acts as an antimetastatic drug via its vitamin K antagonism, and (2) its antimetastatic activity occurs in association with depression of a peculiar “cancer procoagulant”, a direct activator of coagulation factor X, which appears to be a new vitamin K-dependent activity and a cellular target for warfarin effect.2,9
Investigation of procoagulant activity in extracellular vesicles isolated by differential ultracentrifugation
Published in Journal of Extracellular Vesicles, 2018
Thøger Nielsen, Anne Flou Kristensen, Shona Pedersen, Gunna Christiansen, Søren Risom Kristensen
Isolating exosomes and microvesicles can be achieved through various techniques, including size exclusion chromatography, immunoaffinity precipitation, and ultracentrifugation, however, each technique has both advantages and limitations [10]. There are different available methods to study the procoagulant activity of EVs. Hisada et al. describes two assays to measure microvesicle TF-dependent generation of activated coagulation factor X (FXa) [11]. Another approach is to evaluate the overall procoagulant effect of EVs by using a modified version of the thrombin generation assay (TGA) described by Hemker et al. [12]. This has been tested in patients with thrombosis or cancer [13,14]. Marchetti and co-workers [15] reported evidence of procoagulant phospholipid (PPL) activity in thrombocythemia patients using a combination of TGA and a PPL activity assay. However, the methods available to study the procoagulant effect of EVs retain certain limitations. Thus, the combination of assays with increased sensitivity towards TF and phosphatidylserine and quantitative and phenotypical analyses of EVs may convey a more accurate profile of procoagulant EV activity. This may, in a clinical perspective, help clarify the role of EVs in coagulation in identifying certain procoagulant patient groups or individual patients at risk of developing venous thromboembolism.
COVID-19 and venous thromboembolism: current insights and prophylactic strategies
Published in Annals of Medicine, 2020
Pasquale Ambrosino, Alessandro Di Minno, Mauro Maniscalco, Matteo Nicola Dario Di Minno
Thus, considering the high thrombotic risk of severe COVID-19 patients, it seems more reasonable to make a choice based on the different pharmacokinetic profiles of heparins rather than prescribing therapeutic doses regimens in the absence of specific indication. Another approach that could be adopted to optimise the antithrombotic prophylaxis in this clinical setting is the monitoring of anti-activated coagulation factor X (Xa) activity. Despite many limitations, anti-Xa assay remains the only available method to monitor LMWH efficacy [41]. Similarly, a very strict monitoring of activated partial thromboplastin time (aPTT) could be of help when UFH is chosen.
Verification of a proteomic biomarker panel to diagnose minor stroke and transient ischaemic attack: phase 1 of SpecTRA, a large scale translational study
Published in Biomarkers, 2018
Andrew M. Penn, Maximilian B. Bibok, Viera K. Saly, Shelagh B. Coutts, Mary L. Lesperance, Robert F. Balshaw, Kristine Votova, Nicole S. Croteau, Anurag Trivedi, Angela M. Jackson, Janka Hegedus, Evgenia Klourfeld, Amy Y. X. Yu, Charlotte Zerna, Christoph H. Borchers
Coagulation factor X (FX) is a known marker of cardiac disease (Redondo et al.1999). In our study, increased levels of FX were found to be predictive of TIA/minor stroke. FX has been found to be significantly higher in acute-phase ischaemic stroke patients compared to stroke patients 1–4 years post-event (Gissel et al.2010), as well as in stroke patients 2 months post-event compared to healthy controls (Biasiutti et al.2003).