SOX9-regulated matrix proteins predict poor outcomes in patients with COVID-19 and pulmonary fibrosis (preprint)

Pulmonary fibrosis is an increasing and major cause of death worldwide. Understanding the cellular and molecular mechanisms underlying the pathophysiology of lung fibrosis may lead to urgently needed diagnostic and prognostic strategies for the disease. SOX9 is a core transcription factor that has been associated with fibrotic disease, however its role and regulation in acute lung injury and/or fibrosis have not been fully defined. In this study we apply a hypothesis based approach to uncover unique SOX9-protein signatures associated with both acute lung injury and fibrotic progression. Using in vivo models of lung injury in the presence or absence of SOX9, our study shows SOX9 is essential to the damage associated response of alveolar epithelial cells from an early time-point in lung injury. In parallel, as disease progresses, SOX9 is responsible for regulating tissue damaging ECM production from pro-fibrotic fibroblasts. In determining the in vivo role of SOX9 we identified secreted ECM components downstream of SOX9 as markers of acute lung injury and fibrosis. To underscore the translational potential of our SOX9-regulated markers, we analysed serum samples from acute COVID19, post COVID19 and idiopathic pulmonary fibrosis (IPF) patient cohorts. Our hypothesis driven SOX9-panels showed significant capability in all cohorts at identifying patients who had poor disease outcomes. This study shows that SOX9 is functionally critical to disease in acute lung injury and pulmonary fibrosis and its regulated pathways have diagnostic, prognostic and therapeutic potential in both COVID19 and IPF disease.

Development of a novel angiotensin converting enzyme 2 stimulator with broad implications in SARS-CoV2 and type 1 diabetes (preprint)

Angiotensin-converting enzyme 2 (ACE2) is protective in cardiovascular disease, lung injury and diabetes yet paradoxically underlies our susceptibility to SARs-CoV2 infection and the fatal heart and lung disease it can induce. Furthermore, diabetic patients have chronic, systemic inflammation and altered ACE2 expression resulting in increased risk of severe COVID-19 and the associated mortality. A drug that could increase ACE2 activity and inhibit cellular uptake of severe acute respiratory syndrome coronavirus 2 (SARs-CoV2), thus decrease infection, would be of high relevance to cardiovascular disease, diabetes and SARs-CoV2 infection. While the need for such a drug lead was highlighted over a decade ago receiving over 600 citations,1 to date, no such drugs are available.2 Here, we report the development of a novel ACE2 stimulator, designated ‘2A’(international PCT filed), which is a 10 amino acid peptide derived from a snake venom, and demonstrate its in vitro and in vivo efficacy against SARs-CoV2 infection and associated lung inflammation. Peptide 2A also provides remarkable protection against glycaemic dysregulation, weight loss and disease severity in a mouse model of type 1 diabetes. No untoward effects of 2A were observed in these pre-clinical models suggesting its strong clinical translation potential. 

Pharmacological inhibition of TBK1/IKKε blunts COVID-19 immunopathology (preprint)

TANK-binding kinase 1 (TBK1) is a key signalling component that drives the production of type-I interferons (IFNs), which have essential antiviral activities including against SARS-CoV-2. TBK1 and its homolog IκB kinase-ε (IKKε) can also induce the production of pro-inflammatory factors that contribute to pathogen clearance. While initially protective, delayed engagement of type-I IFN is associated with lethal hyper-inflammation seen in severe COVID-19 patients. The contribution of TBK1/IKKε signalling to this response is unknown. We have discovered that the small molecule idronoxil inhibits both IRF3 and NF-κB-driven inflammation by disrupting the formation of TBK1/IKKε signalling complexes following STING activation. Leveraging this unique activity, we show that therapeutic administration of idronoxil suppresses cellular and molecular lung inflammation in K18-hACE2 mice challenged with SARS-CoV-2, resulting in reduced pro-inflammatory cytokine production and decreased airway fibrosis in experimental COVID-19. Our results indicate a critical role for TBK1/IKKε signalling in SARS-CoV-2 hyper-inflammation and identify a novel therapeutic intervention to limit disease severity in COVID-19 patients.

Mucosal TLR2-activating protein-based vaccination induces potent pulmonary immunity and protection against SARS-CoV-2 in mice (preprint)

Current vaccines against SARS-CoV-2 substantially reduce mortality, but protection against infection is less effective. Enhancing immunity in the respiratory tract, via mucosal vaccination, may provide protection against infection and minimise viral spread. We tested a novel subunit vaccine in mice, consisting of SARS-CoV-2 Spike protein with a TLR2-stimulating adjuvant, delivered to mice parenterally or mucosally. Both routes of vaccination induced substantial neutralising antibody (nAb) titres, however, mucosal vaccination uniquely generated anti-Spike IgA, increased nAb in the serum and airways, and increased lung CD4 + T-cell responses. TLR2 is expressed by respiratory epithelia and immune cells. Using TLR2 deficient chimeric mice, we determined that TLR2 expression in either compartment facilitated early innate responses to mucosal vaccination. By contrast, TLR2 on hematopoietic cells was essential for optimal lung-localised, antigen-specific responses. In a K18-hACE2 mice, vaccination provided complete protection against disease and sterilising lung immunity against SARS-CoV-2. These data support mucosal vaccination as a strategy to improve protection in the respiratory tract against SARS-CoV-2 and other respiratory viruses.