Treatment with anti-inflammatory viral serpin modulates immuno-thrombotic responses and improves outcomes in SARS-CoV-2 infected mice

Abstract

Severe acute respiratory distress syndrome (ARDS) during SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) infection, manifests as uncontrolled lung inflammation and systemic thrombosis with high mortality. Anti-viral drugs and monoclonal antibodies can reduce COVID-19 severity if administered in the early viremic phase, but treatments for later stage immuno-thrombotic syndrome and long COVID are limited. Serine protease inhibitors (SERPINS) regulate activated proteases during thrombotic, thrombolytic and immune responses. The myxoma poxvirus-derived Serp-1 protein is a secreted immunomodulatory serpin that targets activated coagulation and complement protease pathways as part of a self-defense strategy to combat viral clearance by the innate immune system. When purified and utilized as an anti-immune therapeutic, Serp-1 is effective as an anti-inflammatory drug in multiple animal models of inflammatory lung disease and vasculitis. Here, we describe systemic treatment with purified PEGylated Serp-1 (PEGSerp-1) as a therapy for immuno-thrombotic complications during ARDS. Treatment with PEGSerp-1 in two distinct mouse-adapted SARS-CoV-2 models in C57Bl/6 and BALB/c mice reduced lung and heart inflammation, with improved clinical outcomes. PEGSerp-1 significantly reduced M1 macrophage invasion in the lung and heart by modifying urokinase-type plasminogen activator receptor (uPAR) and complement membrane attack complex (MAC). Sequential changes in urokinase-type plasminogen activator receptor (uPAR) and serpin gene expression were observed in lung and heart with PEGSerp-1 treatment. PEGSerp-1 is a highly effective immune-modulator with therapeutic potential for treatment of severe viral ARDS with additional potential to reduce late SARS-CoV-2 complications related to immune-thrombotic events that persist during long COVID. Significance: Severe acute respiratory distress syndrome (ARDS) in SARS-CoV-2 infection manifests as uncontrolled tissue inflammation and systemic thrombosis with high mortality. Anti-viral drugs and monoclonal antibodies reduce COVID-19 severity if administered early, but treatments for later stage immuno-thrombosis are limited. Serine protease inhibitors (SERPINS) regulate thrombotic, thrombolytic and complement pathways. We investigate here systemic treatment with purified poxvirus-derived PEGSerp-1 as a therapeutic for immuno-thrombotic complications in viral ARDS. PEGSerp-1 treatment in two mouse-adapted SARS-CoV-2 models (C57Bl/6 and BALB/c) significantly reduced lung and heart inflammation and improved clinical outcomes, with sequential changes in thrombolytic (uPAR) and complement expression. PEGSerp-1 is a highly effective immune-modulator with therapeutic potential for immune-thrombotic complications in severe viral ARDS and has potential benefit for long COVID.

Circulating Soluble Urokinase Plasminogen Activator Receptor as a Predictive Indicator for COVID-19-Associated Acute Kidney Injury and Mortality: Clinical and Bioinformatics Analysis

“…This activity suggested its possible impact in decreasing the deleterious effect of high suPAR on kidney function and associated COVID-19 severity. Our finding was consistent with Zhang et al, who examined SERPINE treatment of severe immune-mediated lung damage in SARS-CoV-2 viral infections in mice models and found its effectiveness in preventing disease-mediated damage [ 29 ]. It is worth noting that the role of serpins and anti-PLAUR in the fibrinolysis process in COVID-19 is complex, and investigations on the potential therapeutic modulation of these processes with natural, virus-derived, or engineered serpins, expanding the consideration of these proteins beyond only regulation of the fibrinolytic system, may be a valuable pursuit as many of these modulators are already found to be safe and effective, and in some cases, FDA-approved [ 11 ].…”

Systemic Dosing of Virus-derived Serpin Improves Survival and Immunothrombotic Damage in Murine Colitis

“…Thrombotic, thrombolytic and inflammatory proteases drive colon inflammation and damage as well as vascular disease. PEGSerp-1 binds the thrombolytic pathway proteases tPA and uPA, the thrombotic proteases fX and thrombin, and immune mediating uPA/uPAR complexes and selective complement proteases (23)(24)(25)(32)(33)(34). Systemic PEGSerp-1 treatment was evaluated here in DSS-induced colitis pre-clinical models of IBD, demonstrating improved survival and reduced colon inflammation and damage with reduced macrophage invasion and improved marker levels for thrombosis, uPAR and complement MAC when given as an acute prophylaxis in higher dose DSS colitis model and with acute exacerbations in a chronic lower dose DSS colitis model.…”

“…PEGSerp-1, has improved pharmacokinetic properties (33,34). PEGSerp-1 is a modified virus-derived serpin, with systemic anti-inflammatory activities in a range of animal models of vascular diseases associated with immune and coagulation pathway dysfunction (17, 33,34).…”

“…Serp-1 (m008.1L; NCBI Gene ID# 932146) was expressed in a Chinese hamster ovary (CHO) cell line in (33)(34)(35)42) as previously described to GMP-compliant standards. This was >95% pure, as determined by Coomassie stained SDS-PAGE and reverse-phase HPLC and endotoxin-free by limulus amebocyte lysate assay.…”

“…Serp-1 is a secreted 55kDa glycosylated MyxV-derived serpin that binds and inhibits tPA, uPA, and plasmin in the thrombolytic cascade, and factor Xa (fXa) and thrombin in the thrombotic cascade (23)(24)(25)(30)(31)(32)(33)(34) . Additionally, Serp-1 targets several complement proteases including C1s (25,33), and more recently demonstrated to bind a series of complement proteases with reduced complement membrane attack complex (MAC, C5b/9) detection after Serp-1 treatment in animal models of inflammatory disease (33,34). Outside of the context of a viral infection, these modulatory effects on inflammation represent clinically desirable properties that give this molecule therapeutic potential.…”