Project description:Clinical characteristics and peripheral blood were acquired upon hospital admission from two well characterised cohorts, a cohort of patients infected with influenza and a cohort of patients infected with SARS-CoV-2 during the first wave of the pandemic and prior to availability of COVID-19 treatments and vaccines.
Project description:The COVID-19 pandemic caused by SARS-CoV-2 has reached 5.5 million deaths worldwide, causing a huge impact globally. This highly contagious viral infection produces a severe acute respiratory syndrome that includes cough, mucus, fever and pneumonia. Likewise, many hospitalized patients develop severe pneumonia associated with acute respiratory distress syndrome (ARDS), besides an exacerbated and uncontrolled systemic inflammation which in some cases induce lethal cytokine storm. Although vaccines have clearly had a beneficial effect on disease development, there is still a high percentage of patients who develop pathology related to ineffective immune system response. Therefore, a thorough understanding of the modulatory mechanisms that regulate the response to SARS-CoV-2 is crucial to find effective therapeutic alternatives. Previous studies describe the relevance of Neddylation in immune system activation further its implications in viral infection. In this context, the present study postulates Neddylation, a reversible ubiquitin-like post-translational modification of proteins and controls their stability, localization and activity, as a key regulator in the immune response against SARS-CoV-2. For the first time, we describe an increase of serum global neddylation levels of COVID-19 patients particularly associated in the early response of the infection. In addition, the results showed that overactivation of neddylation control activation, proliferation, and response of peripheral blood mononuclear cells (PBMCs) derived from COVID-19 patients. Inhibition of neddylation and subsequent avoidance of activation of PBMCs, which reduces cytokine production and proteome modulation, may therefore be a critical mechanism and an efficient therapeutic approach to immunomodulate COVID -19 patients and avoid the much-feared cytokine storm.
Project description:Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has been associated with neurological and neuropsychiatric illness in many individuals. We sought to further our understanding of the relationship between brain tropism, neuro-inflammation and host immune response in acute COVID-19 cases. 3 brain regions (dorsolateral prefrontal cortex, medulla oblongata and choroid plexus) from 5 patients with severe COVID-19 and 4 controls were examined. The presence of virus was assessed by western blot against viral spike protein, as well as viral transcriptome analysis covering >99% of SARS-CoV-2 genome and all potential serotypes. Droplet-based single-nucleus RNA sequencing (snRNA-seq) was performed in the same samples to examine the impact of COVID-19 on transcription in individual cells of the brain. Quantification of viral spike S1 protein and viral transcripts did not detect SARS-CoV-2 in the postmortem brain tissue. However, analysis of 68,557 single-nucleus transcriptomes from three distinct regions of the brain identified an increased proportion of stromal cells, monocytes and macrophages in the choroid plexus of COVID-19 patients. Furthermore, differential gene expression, pseudo-temporal trajectory and gene regulatory network analyses revealed transcriptional changes in cortical microglia associated with a range of biological processes, including cellular activation, mobility and phagocytosis. Despite the absence of detectable SARS-CoV-2 in the brain at time of death, the findings suggest significant and persistent neuroinflammation in patients with acute COVID-19.
Project description:The ongoing SARS-CoV-2 pandemic has resulted in over 6.3 million deaths and 560 million COVID-19 cases worldwide. Clinical management of hospitalised patients is complex due to the heterogeneous course of COVID-19. Low-dose radiotherapy (LD-RT) is known to dampen localised chronic inflammation, and has been suggested to be used to reduce lung inflammation in COVID-19 patients. However, it is unknown whether SARS-CoV-2 alters the radiation response and associated radiation exposure related risk. We generated gene expression profiles from circulating leukocytes of hospitalised COVID-19 patients and healthy donors. The p53 signalling pathway was found to be dysregulated, with mRNA levels of p53, ATM and CHK2 being lower in COVID-19 patients. Several key p53 target genes involved in cell cycle arrest, apoptosis and p53 feedback inhibition were up-regulated in COVID-19 patients, while other p53 target genes were downregulated. This dysregulation has functional consequences as the transcription of p53-dependant genes (CCNG1, GADD45A, DDB2, SESN1, FDXR, APOBEC) was reduced 24 h after X-ray exposure ex-vivo to both low (100 mGy) or high (2 Gy) doses. In conclusion, SARS-CoV-2 infection affects a DNA damage response that may modify radiation-induced health risks in exposed COVID-19 patients.
Project description:Multi-omics single-cell profiling of surface proteins, gene expression and lymphocyte immune receptors from hospitalised COVID-19 patient peripheral blood immune cells and healthy controls donors. Identification of the coordinated immune cell compositional and state changes in response to SARS-CoV-2 infection or LPS challenge, compared to healthy control immune cells.
Project description:While some individuals infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) present mild-to-severe disease, many SARS-CoV-2-infected individuals are asymptomatic. We sought to identify the distinction of immune response between asymptomatic and moderate patients. We performed single-cell transcriptome and T-cell/B-cell receptor (TCR/BCR) sequencing in 37 longitudinal collected peripheral blood mononuclear cell samples from asymptomatic, moderate, and severe patients with healthy controls. Asymptomatic patients displayed increased CD56briCD16- natural killer (NK) cells and upregulation of interferon-gamma in effector CD4+ and CD8+ T cells and NK cells. They showed more robust TCR clonal expansion, especially in effector CD4+ T cells, but lack strong BCR clonal expansion compared to moderate patients. Moreover, asymptomatic patients have lower interferon-stimulated genes (ISGs) expression in general but large interpatient variability, whereas moderate patients showed various magnitude and temporal dynamics of the ISGs expression across multiple cell populations but lower than a patient with severe disease. Our data provide evidence of different immune signatures to SARS-CoV-2 in asymptomatic infections.
Project description:Since the beginning of the SARS-CoV-2 pandemic, COVID-19 has appeared as a unique disease with unconventional tissue and systemic immune features. While COVID-19 severe forms share clinical and laboratory aspects with various pathologies such as hemophagocytic lymphohistiocytosis, sepsis or cytokine release syndrome, their exact nature remains unknown. This is severely impeding the ability to treat patients facing severe stages of the disease. To this aim, we performed an in-depth, single-cell RNA-seq analysis of more than 150.000 immune cells isolated from matched blood samples and broncho-alveolar lavage fluids of COVID-19 patients and healthy controls, and integrated it with clinical, immunological and functional ex vivo data. We unveiled an immune signature of disease severity that correlated with the accumulation of naïve lymphoid cells in the lung and an expansion and activation of myeloid cells in the periphery. Moreover, we demonstrated that myeloid-driven immune suppression is a hallmark of COVID-19 evolution and arginase 1 expression is significantly associated with monocyte immune regulatory features. Noteworthy, we found monocyte and neutro-phil immune suppression loss associated with fatal clinical outcome in severe patients. Additionally, our analysis discovered that the strongest association of the patients clinical outcome and immune phenotype is the lung T cell response. We found that patients with a robust CXCR6+ effector memory T cell response have better outcomes. This result is line with the rs11385942 COVID-19 risk allele, which is in proximity to the CXCR6 gene and suggest effector memory T cell are a primary feature in COVID-19 patients. By systemically quantifying the viral landscape in the lung of severe patients, we indeed identified Herpes-Simplex-Virus 1 (HSV-1) as a potential opportunistic virus in COVID-19 patients. Lastly, we observed an unexpectedly high SARS-CoV-2 viral load in an immuno-compromised patient, allowing us to study the SARS-CoV-2 in-vivo life cycle. The development of my-eloid dysfunctions and the impairment of lymphoid arm establish a condition of immune paralysis that supports secondary bacteria and virus infection and can progress to “immune silence” in patients facing death.
Project description:Immune characteristics associated with Coronavirus Disease-2019 (COVID-19) severity are currently unclear. We characterized bronchoalveolar lavage fluid (BALF) immune cells from patients with varying severity of COVID-19 disease and from healthy subjects using single-cell RNA-sequencing. Proinflammatory monocyte-derived macrophages were abundant in the BALF from severe COVID-9 patients. Moderate cases were characterized by the presence of highly clonally expanded tissue-resident CD8+ T cells. This atlas of the bronchoalveolar immune-microenvironment suggests potential mechanisms underlying pathogenesis and recovery in COVID-19.
Project description:Infection with SARS-CoV-2 has highly variable clinical manifestations, ranging from asymptomatic infection through to life-threatening disease. Host whole blood transcriptomics can offer unique insights into the biological processes underpinning infection and disease, as well as severity. We performed whole blood RNA-Sequencing of individuals with varying degrees of COVID-19 severity. We used differential expression analysis and pathway enrichment analysis to explore how the blood transcriptome differs between individuals with mild, moderate, and severe COVID-19, performing pairwise comparisons between groups.