Fish Shellfish Immunol. 2017 Jan;60:466-473. doi: 10.1016/j.fsi.2016.11.029. Epub 2016 Nov 10.
A TFPI-1 peptide that induces degradation of bacterial nucleic acids, and inhibits bacterial and viral infection in half-smooth tongue sole, Cynoglossus semilaevis
Shu-Wen He 1, Jian Zhang 2, Ning-Qiu Li 3, Shun Zhou 1, Bin Yue 1, Min Zhang 4
Tissue factor pathway inhibitor 1 (TFPI-1) is a serine protease inhibitor that inhibits tissue factor (TF)-mediated coagulation. The C-terminal region of TFPI-1 could be cleaved off and proved to be antimicrobial against a broad-spectrum of microorganism. In a previous study, a C-terminal peptide, TC24 (with 24 amino acids), derived from tongue sole (Cynoglossus semilaevis) TFPI-1, was synthesized and found antibacterial against Micrococcus luteus. In the present study, the antibacterial spectrum and the action mode of TC24 was further examined, and its in vivo function was analyzed. Our results showed that TC24 also possesses bactericidal activity against Staphylococcus aureus and Vibrio vulnificus. During its interaction with the target bacterial cells, TC24 destroyed cell membrane integrity, penetrated into the cytoplasm, and induced degradation of genomic DNA and total RNA. In vivo study showed that administration of tongue sole with TC24 before bacterial and viral infection significantly reduced pathogen dissemination and replication in tissues. These results indicated that TC24 is a novel antimicrobial peptide against bacterial and viral pathogens, and that the observed effect of TC24 on bacterial RNA adds new insights to the action mechanism of fish antimicrobial peptides. Moreover, TC24 may play an important role in fighting pathogenic infection in aquaculture.
PMID: 17696609 PMCID: PMC1941749 DOI: 10.1371/journal.ppat.0030112
Functional genomics highlights differential induction of antiviral pathways in the lungs of SARS-CoV-infected macaques
Anna de Lang 1, Tracey Baas, Thomas Teal, Lonneke M Leijten, Brandon Rain, Albert D Osterhaus, Bart L Haagmans, Michael G Katze
The pathogenesis of severe acute respiratory syndrome coronavirus (SARS-CoV) is likely mediated by disproportional immune responses and the ability of the virus to circumvent innate immunity. Using functional genomics, we analyzed early host responses to SARS-CoV infection in the lungs of adolescent cynomolgus macaques (Macaca fascicularis) that show lung pathology similar to that observed in human adults with SARS. Analysis of gene signatures revealed induction of a strong innate immune response characterized by the stimulation of various cytokine and chemokine genes, including interleukin (IL)-6, IL-8, and IP-10, which corresponds to the host response seen in acute respiratory distress syndrome. As opposed to many in vitro experiments, SARS-CoV induced a wide range of type I interferons (IFNs) and nuclear translocation of phosphorylated signal transducer and activator of transcription 1 in the lungs of macaques. Using immunohistochemistry, we revealed that these antiviral signaling pathways were differentially regulated in distinctive subsets of cells. Our studies emphasize that the induction of early IFN signaling may be critical to confer protection against SARS-CoV infection and highlight the strength of combining functional genomics with immunohistochemistry to further unravel the pathogenesis of SARS.
PLoS One. 2016 May 25;11(5):e0155832. doi: 10.1371/journal.pone.0155832. eCollection 2016.
Von Willebrand Factor Gene Variants Associate with Herpes simplex Encephalitis
Nada Abdelmagid 1, Biborka Bereczky-Veress 1, Santosh Atanur 2, Alena Musilová 3, Václav Zídek 3, Laura Saba 4, Andreas Warnecke 1, Mohsen Khademi 1, Marie Studahl 5, Elisabeth Aurelius 6, Anders Hjalmarsson 6, Ana Garcia-Diaz 2, Cécile V Denis 7, Tomas Bergström 8, Birgit Sköldenberg 6, Ingrid Kockum 1, Timothy Aitman 2, Norbert Hübner 9, Tomas Olsson 1, Michal Pravenec 3, Margarita Diez 1
Herpes simplex encephalitis (HSE) is a rare complication of Herpes simplex virus type-1 infection. It results in severe parenchymal damage in the brain. Although viral latency in neurons is very common in the population, it remains unclear why certain individuals develop HSE. Here we explore potential host genetic variants predisposing to HSE. In order to investigate this we used a rat HSE model comparing the HSE susceptible SHR (Spontaneously Hypertensive Rats) with the asymptomatic infection of BN (Brown Norway). Notably, both strains have HSV-1 spread to the CNS at four days after infection. A genome wide linkage analysis of 29 infected HXB/BXH RILs (recombinant inbred lines-generated from the prior two strains), displayed variable susceptibility to HSE enabling the definition of a significant QTL (quantitative trait locus) named Hse6 towards the end of chromosome 4 (160.89-174Mb) containing the Vwf (von Willebrand factor) gene. This was the only gene in the QTL with both cis-regulation in the brain and included several non-synonymous SNPs (single nucleotide polymorphism). Intriguingly, in human chromosome 12 several SNPs within the intronic region between exon 43 and 44 of the VWF gene were associated with human HSE pathogenesis. In particular, rs917859 is nominally associated with an odds ratio of 1.5 (95% CI 1.11-2.02; p-value = 0.008) after genotyping in 115 HSE cases and 428 controls. Although there are possibly several genetic and environmental factors involved in development of HSE, our study identifies variants of the VWF gene as candidates for susceptibility in experimental and human HSE.
Front Pharmacol. 2020 Dec 11;11:615398. doi: 10.3389/fphar.2020.615398. eCollection 2020.
Alpha-1 Antitrypsin for COVID-19 Treatment: Dual Role in Antiviral Infection and Anti-Inflammation
Chengliang Yang 1, Shaf Keshavjee 1 2, Mingyao Liu 1 2
Many drugs have been approved for clinical trials for the treatment of COVID-19 disease, focusing on either antiviral or anti-inflammatory approaches. Combining antiviral and anti-inflammatory drugs or therapies together may be more effective. Human alpha-1 antitrypsin (A1AT) is a blood circulating glycoprotein that is best known as a protease inhibitor. It has been used to treat emphysema patients with A1AT deficiency for decades. We and others have demonstrated its role in reducing acute lung injury by inhibiting inflammation, cell death, coagulation, and neutrophil elastase activation. Recently, A1AT has been found to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by inhibiting transmembrane serine protease 2 (TMPRSS2), a protease involved in the entry of SARS-CoV-2 into host cells. This dual role of both antiviral infection and anti-inflammation makes A1AT a unique and excellent candidate for COVID-19 treatment. Three clinical trials of A1AT for COVID-19 treatment have recently been approved in several countries. It is important to determine whether A1AT can prevent the progress from moderate to severe lung injury and eventually to be used to treat COVID-19 patients with acute respiratory distress syndrome.
Version 2. bioRxiv. Preprint. 2020 Oct 7. doi: 10.1101/2020.05.04.077826. This article is a preprint.
Alpha 1 Antitrypsin is an Inhibitor of the SARS-CoV-2-Priming Protease TMPRSS2
Nurit P. Azouz,1,* Andrea M. Klingler,1 Victoria Callahan,2 Ivan V. Akhrymuk,2 Katarina Elez,3 Lluís Raich,3 Brandon M. Henry,4 Justin L. Benoit,5 Stefanie W. Benoit,6,7 Frank Noé,3,8,9 Kylene Kehn-Hall,2 and Marc E. Rothenberg1,7
Host proteases have been suggested to be crucial for dissemination of MERS, SARS-CoV, and SARS-CoV-2 coronaviruses, but the relative contribution of membrane versus intracellular proteases remains controversial. Transmembrane serine protease 2 (TMPRSS2) is regarded as one of the main proteases implicated in the coronavirus S protein priming, an important step for binding of the S protein to the angiotensin-converting enzyme 2 (ACE2) receptor before cell entry. The main cellular location where the SARS-CoV-2 S protein priming occurs remains debatable, therefore hampering the development of targeted treatments. Herein, we identified the human extracellular serine protease inhibitor (serpin) alpha 1 antitrypsin (A1AT) as a novel TMPRSS2 inhibitor. Structural modeling revealed that A1AT docked to an extracellular domain of TMPRSS2 in a conformation that is suitable for catalysis, resembling similar serine protease-inhibitor complexes. Inhibitory activity of A1AT was established in a SARS-CoV-2 viral load system. Notably, plasma A1AT levels were associated with COVID-19 disease severity. Our data support the key role of extracellular serine proteases in SARS-CoV-2 infections and indicate that treatment with serpins, particularly the FDA-approved drug A1AT, may be effective in limiting SARS-CoV-2 dissemination by affecting the surface of the host cells.
Version 1. bioRxiv. Preprint. 2020 Aug 15. doi: 10.1101/2020.08.14.248880. This article is a preprint.
In plain sight: the role of alpha-1-antitrypsin in COVID-19 pathogenesis and therapeutics.
Kasopefoluwa Y Oguntuyo,1,# Christian S Stevens,1,# Mohammed NA Siddiquey,2 Robert M Schilke,2 Matthew D Woolard,2 Hongbo Zhang,2 Joshua A Acklin,1 Satoshi Ikegame,1 Chuan-Tien Huang,1 Jean K Lim,1 Robert W Cross,3 Thomas W Geisbert,3 Stanimir S Ivanov,2 Jeremy P Kamil,2 and Benhur Lee1
Entry of SARS-CoV-2 is facilitated by endogenous and exogenous proteases. These proteases proteolytically activate the SARS-CoV-2 spike glycoprotein and are key modulators of virus tropism. We show that SARS-CoV-2 naïve serum exhibits significant inhibition of SARS-CoV-2 entry. We identify alpha-1-antitrypsin (AAT) as the major serum protease inhibitor that potently restrict protease-mediated entry of SARS-CoV-2. AAT inhibition of protease-mediated SARS-CoV-2 entry in vitro occurs at concentrations far below what is present in serum and bronchoalveolar tissues, suggesting that AAT effects are physiologically relevant. Moreover, AAT deficiency affects up to 20% of the population and its symptomatic manifestations coincides with many risk factors associated with severe COVID-19 disease. In addition to the effects that AAT may have on viral entry itself, we argue that the anti-inflammatory and coagulation regulatory activity of AAT have implications for coronavirus disease 2019 (COVID-19) pathogenicity, SARS-CoV-2 tissue restriction, convalescent plasma therapies, and even potentially AAT therapy.
doi: https://doi.org/10.1101/2020.07.02.183764. Preprint.
Alpha-1 antitrypsin inhibits SARS-CoV-2 infection
Lukas Wettstein, Carina Conzelmann, Janis A. Müller, Tatjana Weil, Rüdiger Groß, Maximilian Hirschenberger, Alina Seidel, Susanne Klute, Fabian Zech, Caterina Prelli Bozzo, Nico Preising, Giorgio Fois, Robin Lochbaum, Philip Knaff, Volker Mailänder, Ludger Ständker, Dietmar Rudolf Thal, Christian Schumann, Steffen Stenger, Alexander Kleger, Günter Lochnit, Konstantin Sparrer, Frank Kirchhoff, Manfred Frick, Jan Münch
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). To identify factors of the respiratory tract that suppress SARS-CoV-2, we screened a peptide/protein library derived from bronchoalveolar lavage, and identified α1-antitrypsin (α1-AT) as specific inhibitor of SARS-CoV-2. α1-AT targets the viral spike protein and blocks SARS-CoV-2 infection of human airway epithelium at physiological concentrations. Our findings show that endogenous α1-AT restricts SARS-CoV-2 and repurposes α1-AT-based drugs for COVID-19 therapy.
Thromb Res. 2020 Jun; 190: 62.
Severe COVID-19 infection associated with endothelial activation
Robert Escher,a Neal Breakey,a,⁎∗ and Bernhard Lämmleb,c,d
Mounting evidence supports the strong prognostic importance of D-dimers and the impact of coagulopathy in COVID-19 patients [1,2,3]. We would like to emphasize the significance of anticoagulation in severe COVID-19 disease, by adding our observation of highly pathological data on anti-phospholipid-antibodies, von Willebrand Factor (VWF) and Factor VIII. We observed a 72-year-old previously healthy male patient admitted to our hospital 6 days after the onset of respiratory symptoms and fever. Six days after admission, following a rapid deterioration of his clinical condition with development of acute respiratory distress syndrome, acute renal insufficiency and altered mental status, he was transferred to the intensive care unit (ICU). Supportive care with intubation, positive pressure ventilation and renal replacement therapy led to a stabilization of his condition. During the ICU stay, a continual increase of D-dimers was observed, from initially 0.69 mg/L to 2.55 mg/L on day 4, 2.81 mg/L on day 11 to 20.63 mg/L on day 21. At this time, IgG anti-cardiolipin antibodies (ACA) and anti-beta2-glycoprotein I (anti-β2-GPI) were negative, but IgM ACA elevated at 121.9 CU (normal <20 CU) and IgM anti-β2-GPI elevated at 275.3 CU (normal <20 CU). Furthermore, on day 21, we also observed a concurrent massive elevation of VWF, with VWF:antigen 555% (normal 42–136%) and VWF:activity 520% (normal 42–168%), accompanied by an increase of Factor VIII clotting activity of 369% (normal 55–164%). The increased VWF points towards massive endothelial stimulation and damage with release of VWF from Weibel-Palade bodies. Interestingly, endothelial cells express ACE2, the receptor for SARS-CoV-2, thus possibly mediating endothelial activation . The patient received prophylactic anticoagulation with dalteparin 5000 U s.c. daily from admission to hospital. We increased the dose to therapeutic anticoagulation with unfractionated heparin on day 21, without hemorrhagic complication. Since then, the patient is steadily improving, ventilation and hemodialysis could be successfully withdrawn, and he has been transferred from the ICU to a general ward. D-dimers decreased to 6.26 mg/L on day 24 and to 1.94 mg/L on day 29. Considering the high levels of VWF and factor VIII, we strongly suggest administering higher, possibly therapeutic doses of anticoagulation to these patients. The role of antiphospholipid antibodies, VWF and FVIII needs further study.
Am J Cardiovasc Drugs. 2020 Sep 12 : 1–9.
Potential Therapeutic Roles for Direct Factor Xa Inhibitors in Coronavirus Infections
Rami A. Al-Horanicorresponding author
Human factor Xa (FXa) is a serine protease of the common coagulation pathway. FXa is known to activate prothrombin to thrombin, which eventually leads to the formation of cross-linked blood clots. While this process is important in maintaining hemostasis, excessive thrombin generation results in a host of thrombotic conditions. FXa has also been linked to inflammation via protease-activated receptors. Together, coagulopathy and inflammation have been implicated in the pathogenesis of viral infections, including the current coronavirus pandemic. Direct FXa inhibitors have been shown to possess anti-inflammatory and antiviral effects, in addition to their established anticoagulant activity. This review summarizes the pharmacological activities of direct FXa inhibitors, their pharmacokinetics, potential drug–drug interactions and adverse effects, and the details of clinical trials involving direct FXa inhibitors in coronavirus disease 2019 (COVID-19) patients.
Science. 2014 Sep 5; 345(6201): 1256070.
Intracellular sensing of complement C3 activates cell autonomous immunity
Jerry C.H. Tam,1 Susanna R. Bidgood,1 William A. McEwan,1 and Leo C. James1,*
Pathogens traverse multiple barriers during infection including cell membranes. Here we show that during this transition pathogens carry covalently attached complement C3 into the cell, triggering immediate signalling and effector responses. Sensing of C3 in the cytosol activates MAVS-dependent signalling cascades and induces proinflammatory cytokine secretion. C3 also flags viruses for rapid proteasomal degradation, thereby preventing their replication. This system can detect both viral and bacterial pathogens but is antagonized by enteroviruses, such as rhinovirus and poliovirus, which cleave C3 using their 3C protease. The antiviral Rupintrivir inhibits 3C protease and prevents C3 cleavage, rendering enteroviruses susceptible to intracellular complement sensing. Thus, complement C3 allows cells to detect and disable pathogens that have invaded the cytosol.