Transcriptional response modules characterise IL-1 and IL-6 activity in COVID-19 (preprint)

Dysregulated IL-1{beta} and IL-6 responses have been implicated in the pathogenesis of severe Coronavirus Disease 2019 (COVID-19). Innovative approaches for evaluating the biological activity of these cytokines in vivo are urgently needed to complement clinical trials of therapeutic targeting of IL-1{beta} and IL-6 in COVID-19. We show that the expression of IL-1{beta} or IL-6 inducible transcriptional signatures (modules) reflects the bioactivity of these cytokines in immunopathology modelled by juvenile idiopathic arthritis (JIA) and rheumatoid arthritis. In COVID-19, elevated expression of IL-1{beta} and IL-6 response modules, but not the cytokine transcripts themselves, is a feature of infection in the nasopharynx and blood, but is not associated with severity of COVID-19 disease, length of stay or mortality. We propose that IL-1{beta} and IL-6 transcriptional response modules provide a dynamic readout of functional cytokine activity in vivo, aiding quantification of the biological effects of immunomodulatory therapies in COVID-19.

Identification of Immune complement function as a determinant of adverse SARS-CoV-2 infection outcome (preprint)

Understanding the pathophysiology of SARS-CoV-2 infection is critical for therapeutics and public health intervention strategies. Viral-host interactions can guide discovery of regulators of disease outcomes, and protein structure function analysis points to several immune pathways, including complement and coagulation, as targets of the coronavirus proteome. To determine if conditions associated with dysregulation of the complement or coagulation systems impact adverse clinical outcomes, we performed a retrospective observational study of 11,116 patients who presented with suspected SARS-CoV-2 infection. We found that history of macular degeneration (a proxy for complement activation disorders) and history of coagulation disorders (thrombocytopenia, thrombosis, and hemorrhage) are risk factors for morbidity and mortality in SARS-CoV-2 infected patients - effects that could not be explained by age, sex, or history of smoking. Further, transcriptional profiling of nasopharyngeal (NP) swabs from 650 control and SARS-CoV-2 infected patients demonstrated that in addition to innate Type-I interferon and IL-6 dependent inflammatory immune responses, infection results in robust engagement and activation of the complement and coagulation pathways. Finally, we conducted a candidate driven genetic association study of severe SARS-CoV-2 disease. Among the findings, our scan identified putative complement and coagulation associated loci including missense, eQTL and sQTL variants of critical regulators of the complement and coagulation cascades. In addition to providing evidence that complement function modulates SARS-CoV-2 infection outcome, the data point to putative transcriptional genetic markers of susceptibility. The results highlight the value of using a multi-modal analytical approach, combining molecular information from virus protein structure-function analysis with clinical informatics, transcriptomics, and genomics to reveal determinants and predictors of immunity, susceptibility, and clinical outcome associated with infection.

Identification of Immune complement function as a determinant of adverse SARS-CoV-2 infection outcome (preprint)

Understanding the pathophysiology of SARS-CoV-2 infection is critical for therapeutics and public health intervention strategies. Viral-host interactions can guide discovery of regulators of disease outcomes, and protein structure function analysis points to several immune pathways, including complement and coagulation, as targets of the coronavirus proteome. To determine if conditions associated with dysregulation of the complement or coagulation systems impact adverse clinical outcomes associated with SARS-CoV-2 infection, we performed a retrospective observational study of 11,116 patients suspected of SARS-CoV-2 infection. We found that history of macular degeneration (a proxy for complement activation disorders) and history of coagulation disorders (thrombocytopenia, thrombosis, and hemorrhage) are risk factors for morbidity and mortality in SARS-CoV-2 infected patients – effects that could not be explained by age or sex. In addition, using data from the UK Biobank, we implemented a candidate driven approach to evaluate linkage between severe SARS-CoV-2 disease and genetic variation associated with complement and coagulation pathways. Among our findings, our scan identified an eQTL for CD55 (a negative regulator of complement activation) and SNPs in Complement Factor H (CFH) and Complement Component 4 Binding Protein Alpha (C4BPA), which play central roles in complement activation and innate immunity and were previously linked to Age Related Macular Degeneration (AMD) in a Genome-Wide Association Study (GWAS). In addition to providing evidence that complement function modulates SARS-CoV-2 infection outcome, the data point to several putative genetic markers of susceptibility. The results highlight the value of using a multi-modal analytical approach, combining molecular information from virus protein structure-function analysis with clinical informatics and genomics to reveal determinants and predictors of immunity, susceptibility, and clinical outcome associated with infection.