Project description:ACE2 on epithelial cells is the SARS-CoV-2 entry receptor. Single-cell RNA-sequencing data derived from two COVID-19 cohorts revealed that MAP4K3/GLK-positive epithelial cells were increased in patients. SARS-CoV-2-induced GLK overexpression in epithelial cells correlated with COVID-19 severity and vesicle secretion. GLK overexpression induced the epithelial cell-derived exosomes containing ACE2; the GLK-induced exosomes transported ACE2 proteins to recipient cells, facilitating pseudovirus infection. Consistently, ACE2 proteins were increased in the serum exosomes from another COVID-19 cohort. Remarkably, SARS-CoV-2 spike protein stimulated GLK, and GLK stabilized ACE2 in epithelial cells. Mechanistically, GLK phosphorylated ACE2 at two serine residues (Ser776, Ser783), leading to dissociation of ACE2 from its E3 ligase UBR4. Reduction of UBR4-induced Lys48-linked ubiquitination at three lysine residues (Lys26, Lys112, Lys114) of ACE2 prevented its degradation. Furthermore, SARS-CoV-2 pseudovirus or live virus infection in humanized ACE2 mice induced GLK and ACE2 protein levels, as well as ACE2-containing exosomes. Collectively, ACE2 stabilization by SARS-CoV-2-induced MAP4K3/GLK may contribute to the pathogenesis of COVID-19.
Project description:Bat sarbecovirus BANAL-236 is highly related to SARS-CoV-2 and infects human cells, albeit lacking the furin cleavage site in its spike protein. BANAL-236 replicates efficiently and pauci-symptomatically in humanized mice and in macaques, where its tropism is enteric, strongly differing from that of SARS-CoV-2. BANAL-236 infection leads to protection against superinfection by a virulent strain. We find no evidence of antibodies recognizing bat sarbecoviruses in populations in close contact with bats in which the virus was identified, indicating that such spillover infections, if they occur, are rare. Six passages in humanized mice or in human intestinal cells, mimicking putative early spillover events, select adaptive mutations without appearance of a furin cleavage site and no change in virulence. Therefore, acquisition of a furin site in the spike protein is likely a pre-spillover event that did not occur upon replication of a SARS-CoV-2-like bat virus in humans or other animals. Other hypotheses regarding the origin of the SARS-CoV-2 should therefore be evaluated, including the presence of sarbecoviruses carrying a spike with a furin cleavage site in bats.
Project description:ObjectiveTo summarise study descriptions of the James Lind Alliance (JLA) approach to the priority setting partnership (PSP) process and how this process is used to identify uncertainties and to develop lists of top 10 priorities.DesignScoping review.Data sourcesThe Embase, Medline (Ovid), PubMed, CINAHL and the Cochrane Library as of October 2018.Study selectionAll studies reporting the use of JLA process steps and the development of a list of top 10 priorities, with adult participants aged 18 years.Data extractionA data extraction sheet was created to collect demographic details, study aims, sample and patient group details, PSP details (eg, stakeholders), lists of top 10 priorities, descriptions of JLA facilitator roles and the PSP stages followed. Individual and comparative appraisals were discussed among the scoping review authors until agreement was reached.ResultsDatabase searches yielded 431 potentially relevant studies published in 2010-2018, of which 37 met the inclusion criteria. JLA process participants were patients, carers and clinicians, aged 18 years, who had experience with the study-relevant diagnoses. All studies reported having a steering group, although partners and stakeholders were described differently across studies. The number of JLA PSP process steps varied from four to eight. Uncertainties were typically collected via an online survey hosted on, or linked to, the PSP website. The number of submitted uncertainties varied across studies, from 323 submitted by 58 participants to 8227 submitted by 2587 participants.ConclusionsJLA-based PSP makes a useful contribution to identifying research questions. Through this process, patients, carers and clinicians work together to identify and prioritise unanswered uncertainties. However, representation of those with different health conditions depends on their having the capacity and resources to participate. No studies reported difficulties in developing their top 10 priorities.
Project description:In less than five months, COVID-19 has spread from a small focus in Wuhan, China, to more than 5 million people in almost every country in the world, dominating the concern of most governments and public health systems. The social and political distresses caused by this epidemic will certainly impact our world for a long time to come. Here, we synthesize lessons from a range of scientific perspectives rooted in epidemiology, virology, genetics, ecology and evolutionary biology so as to provide perspective on how this pandemic started, how it is developing, and how best we can stop it.
Project description:The objective of the study was to characterize the immunoreactivity profiles of IgG-reactive epitopes in COVID-19 patients with distinct disease trajectories as well as SARS-CoV-2-naïve sera, using a high-density SARS-CoV-2 whole proteome peptide microarray. The microarray comprised of a total of 5347 individual peptides, each consisting of 15 amino acids with an overlap of 13 amino acids printed in duplicate. The microarray also had a panel of the most relevant mutations from SARS-CoV-2 variants of concern like omicron, alpha, beta, gamma, delta, and others. This study consisted of 29 participants, including 10 naïve controls (5 pre-pandemic and 5 SARS-CoV-2 seronegative) and 19 RT-PCR-confirmed COVID-19 patients. The COVID-19 patients were stratified into two distinct cohorts based on their disease trajectories: the severe cohort (S), in which the patients presented moderate COVID-19 symptoms initially but eventually progressed toward severity; and the recovered cohort (R), in which severe COVID-19 patients progressed toward recovery. Our findings contribute to a deeper understanding of the immunopathogenesis of COVID-19 in patients with different disease trajectories, the effect of mutations on immunoreactivity, and potential cross-reactivity due to exposure to common cold viruses.
Project description:COVID-19, caused by SARS-CoV-2, can result in acute respiratory distress syndrome and multiple-organ failure, but little is known about its pathophysiology. Here, we generated single-cell atlases of 23 lung, 16 kidney, 15 liver and 18 heart COVID-19 autopsy donor tissue samples, and spatial atlases of 14 lung donors. Integrated computational analysis uncovered substantial remodeling in the lung epithelial, immune and stromal compartments, with evidence of multiple paths of failed tissue regeneration, including defective alveolar type 2 differentiation and expansion of myofibroblasts and putative TP63+ intrapulmonary basal-like progenitor cells. Viral RNAs were enriched in mononuclear phagocytic and endothelial lung cells which induced specific host programs. Spatial analysis in lung distinguished inflammatory host responses in lung regions with and without viral RNA. Analysis of the other tissue atlases showed transcriptional alterations in multiple cell types in COVID-19 donor heart tissue, and mapped cell types and genes implicated with disease severity based on COVID-19 GWAS. Our foundational dataset elucidates the biological impact of severe SARS-CoV-2 infection across the body a key step towards new treatments.