Mouse gut and human gut xenograft - PBS control vs Lipopolysaccharide (LPS) treated raw sequence reads
Ontology highlight
ABSTRACT: Background: Gastrointestinal symptoms in COVID-19 patients suggests that the gut may present a viral target organ. Disease development and severity is dependent on viral interaction with two cell surface human proteins, ACE2 and TMPRSS2, and on antiviral response which may lead to systemic hyperinflammatory syndrome and multiorgan dysfunction Understanding the host response to SARS-CoV-2 infection and the pathology of the disease will be greatly enhanced by the development of appropriate animal models. However, the virus does not grow in wild type mice and only induced mild disease in transgenic animals expressing human ACE2. Results: As there are known differences between immune response in laboratory mice and humans, the response of human gut developed as xenografts and host mouse gut following systemic LPS injections as a hyperinflammation model system was evaluated. Gene set enrichment analysis of significantly upregulated human and mouse genes revealed that a number of inflammatory and immune response pathways are commonly regulated in the two species. However, species differences were also observed. The analysis shows that the intestinal immune response to inflammation in humans and mice are generally very similar. However, certain human-specific diseases, such as COVID-19, can only be successfully studied in an experimental model of human tissue, such as the gut xenograft
Project description:The gut microbiome is intricately coupled with immune regulation and metabolism, but its role in Coronavirus Disease 2019 (COVID-19) is not fully understood. Severe and fatal COVID-19 is characterized by poor anti-viral immunity and hypercoagulation, particularly in males. Here we define multiple pathways by which the gut microbiome protects mammalian hosts from SARS-CoV-2 intranasal infection, both locally and systemically, via production of short-chain fatty acids (SCFAs). SCFAs reduced viral burdens in the airways and intestines by downregulating the SARS-CoV-2 entry receptor, angiotensin-converting enzyme 2 (ACE2), and enhancing adaptive immunity in male animals. In order to identify other mechanisms by which SCFAs influence the outcome of SARS-CoV-2 infection, we performed RNA-seq on lungs from male GF mice given control or SCFA water for two weeks. We identified a novel role for the gut microbiome in regulating systemic coagulation response by limiting megakaryocyte proliferation and platelet turnover via the Sh2b3-Mpl axis. Taken together, our findings have unraveled novel functions of SCFAs and fiber-fermenting gut bacteria that might be leveraged as pan-coronavirus therapeutics to dampen viral entry and hypercoagulation and promote adaptive anti-viral immunity.
Project description:The gut microbiome is intricately coupled with immune regulation and metabolism, but its role in Coronavirus Disease 2019 (COVID-19) is not fully understood. Severe and fatal COVID-19 is characterized by poor anti-viral immunity and hypercoagulation, particularly in males. Via 16S sequencing of antibiotic-treated mice, we found that Clostridia species protect mammalian hosts from SARS-CoV-2 intranasal infection, both locally and systemically, via production of short-chain fatty acids (SCFAs). SCFAs reduced viral burdens in the airways and intestines by downregulating the SARS-CoV-2 entry receptor, angiotensin-converting enzyme 2 (ACE2), and enhancing adaptive immunity in male animals. In order to identify other mechanisms by which SCFAs influence the outcome of SARS-CoV-2 infection, we performed RNA-seq on lungs from male GF mice given control or SCFA water for two weeks. We identified a novel role for the gut microbiome in regulating systemic coagulation response by limiting megakaryocyte proliferation and platelet turnover via the Sh2b3-Mpl axis. Taken together, our findings have unraveled novel functions of SCFAs and fiber-fermenting gut bacteria that might be leveraged as pan-coronavirus therapeutics to dampen viral entry and hypercoagulation and promote adaptive anti-viral immunity.
Project description:SARS-CoV-2, the agent causing COVID-19, invades epithelial cells, including those of the respiratory and gastrointestinal mucosa, using angiotensin-converting enzyme-2 (ACE2) as a receptor. Subsequent inflammation can promote rapid virus clearance. However, severe cases of COVID-19 are characterized by an inefficient immune response that fails to clear infection. Using primary epithelial organoids from the colon, we explored how IFN-γ, a central antiviral mediator elevated in COVID-19, affects differentiation, ACE2 expression, and infectivity with SARS-CoV-2. ACE2 is mainly expressed by surface enterocytes of mouse and human colon. Inducing enterocyte differentiation in organoid culture resulted in increased ACE2 production. IFN-γ treatment promoted differentiation into mature KRT20+ enterocytes expressing high levels of ACE2. Similarly, IFN-γ promoted expression of ACE2 in human primary lung cells. IFN-y driven differentiation increased susceptibility to SARS-CoV-2 infection and electron microscopy revealed that the virus can efficiently complete its full life cycle in IFN-γ-treated enterocytes. Furthermore, infection-induced epithelial interferon signaling promoted enterocyte maturation and enhanced ACE2 expression. We reveal a mechanism by which IFN-y-driven inflammatory responses may increase susceptibility to SARS-CoV-2 and promote its replication.
Project description:SARS-CoV-2 infects epithelial cells of the human gastrointestinal (GI) tract and causes related symptoms. HIV infection impairs gut homeostasis and is associated with an increased risk of COVID-19 fatality. To investigate the potential link between these observations, we analyzed single-cell transcriptional profiles and SARS-CoV-2 entry receptor expression across lymphoid and mucosal human tissue from chronically HIV-infected individuals and uninfected controls. Absorptive gut enterocytes displayed the highest coexpression of SARS-CoV-2 receptors ACE2, TMPRSS2, and TMPRSS4, of which ACE2 expression was associated with canonical interferon response and antiviral genes. Chronic treated HIV infection was associated with a clear antiviral response in gut enterocytes and, unexpectedly, with a substantial reduction of ACE2 and TMPRSS2 target cells. Gut tissue from SARS-CoV-2–infected individuals, however, showed abundant SARS-CoV-2 nucleocapsid protein in both the large and small intestine, including an HIV-coinfected individual. Thus, upregulation of antiviral response genes and downregulation of ACE2 and TMPRSS2 in the GI tract of HIV-infected individuals does not prevent SARS-CoV-2 infection in this compartment. The impact of these HIV-associated intestinal mucosal changes on SARS-CoV-2 infection dynamics, disease severity, and vaccine responses remains unclear and requires further investigation.
Project description:We sought to define the host immune response, a.k.a, the “cytokine storm” that has been implicated in fatal COVID-19 using an AI-based approach. Over 45,000 publicly available transcriptomic datasets of viral pandemics were analyzed to extract a 166-gene signature using ACE2 as a ‘seed’ gene; ACE2 was rationalized because the receptor it encodes enables the virus that causes Covid-19, SARS-CoV-2, to enter host cells. The signature was surprisingly conserved in all viral pandemics, including COVID-19, inspiring the nomenclature ViP-signature. A subset of 20-genes classified disease severity in respiratory pandemics. The ViP signatures pinpointed airway epithelial and myeloid cells as the major contributors of an IL-15 cytokine storm, and epithelial and NK cell destruction as determinants of severity/fatality. They also helped formulate precise therapeutic goals to reduce disease symptoms and severity. Thus, the ViP signatures provide a quantitative and qualitative framework for titrating the immune response in viral pandemics and may serve as a powerful unbiased tool in our armamentarium to rapidly assess disease severity and vet candidate drugs.
Project description:We sought to define the host immune response, a.k.a, the “cytokine storm” that has been implicated in fatal COVID-19 using an AI-based approach. Over 45,000 publicly available transcriptomic datasets of viral pandemics were analyzed to extract a 166-gene signature using ACE2 as a ‘seed’ gene; ACE2 was rationalized because the receptor it encodes enables the virus that causes Covid-19, SARS-CoV-2, to enter host cells. The signature was surprisingly conserved in all viral pandemics, including COVID-19, inspiring the nomenclature ViP-signature. A subset of 20-genes classified disease severity in respiratory pandemics. The ViP signatures pinpointed airway epithelial and myeloid cells as the major contributors of an IL-15 cytokine storm, and epithelial and NK cell destruction as determinants of severity/fatality. They also helped formulate precise therapeutic goals to reduce disease symptoms and severity. Thus, the ViP signatures provide a quantitative and qualitative framework for titrating the immune response in viral pandemics and may serve as a powerful unbiased tool in our armamentarium to rapidly assess disease severity and vet candidate drugs.
Project description:We sought to define the host immune response, a.k.a, the “cytokine storm” that has been implicated in fatal COVID-19 using an AI-based approach. Over 45,000 publicly available transcriptomic datasets of viral pandemics were analyzed to extract a 166-gene signature using ACE2 as a ‘seed’ gene; ACE2 was rationalized because the receptor it encodes enables the virus that causes Covid-19, SARS-CoV-2, to enter host cells. The signature was surprisingly conserved in all viral pandemics, including COVID-19, inspiring the nomenclature ViP-signature. A subset of 20-genes classified disease severity in respiratory pandemics. The ViP signatures pinpointed airway epithelial and myeloid cells as the major contributors of an IL-15 cytokine storm, and epithelial and NK cell destruction as determinants of severity/fatality. They also helped formulate precise therapeutic goals to reduce disease symptoms and severity. Thus, the ViP signatures provide a quantitative and qualitative framework for titrating the immune response in viral pandemics and may serve as a powerful unbiased tool in our armamentarium to rapidly assess disease severity and vet candidate drugs.
Project description:We sought to define the host immune response, a.k.a, the “cytokine storm” that has been implicated in fatal COVID-19 using an AI-based approach. Over 45,000 publicly available transcriptomic datasets of viral pandemics were analyzed to extract a 166-gene signature using ACE2 as a ‘seed’ gene; ACE2 was rationalized because the receptor it encodes enables the virus that causes Covid-19, SARS-CoV-2, to enter host cells. The signature was surprisingly conserved in all viral pandemics, including COVID-19, inspiring the nomenclature ViP-signature. A subset of 20-genes classified disease severity in respiratory pandemics. The ViP signatures pinpointed airway epithelial and myeloid cells as the major contributors of an IL-15 cytokine storm, and epithelial and NK cell destruction as determinants of severity/fatality. They also helped formulate precise therapeutic goals to reduce disease symptoms and severity. Thus, the ViP signatures provide a quantitative and qualitative framework for titrating the immune response in viral pandemics and may serve as a powerful unbiased tool in our armamentarium to rapidly assess disease severity and vet candidate drugs.
Project description:Recent data suggests that COVID-19 is a systemic disease affecting multiple organs including the central nervous system. Retinal involvement in COVID-19 has been indicated by several studies, yet many questions remain regarding the ability of SARS-CoV-2 to infect and replicate retinal cells and its effect on the retina. Here we have used human stem cell derived retinal organoids to study retinal infection by SARS-CoV-2. Indeed, SARS-CoV-2 can infect and replicate in retinal organoids, as it is shown to be able to infect different retinal lineages, including retinal ganglion cells and photoreceptors which are the targets of many retinal diseases leading to blindness. SARS-CoV-2 infection of retinal organoids also induces the expression of several inflammatory genes, including Interleukin 33, which is known to be associated with acute COVID-19 disease and with retinal degeneration. Finally, we show that blocking the ACE2 receptor using antibody treatment significantly reduces retinal organoid infection, indicating that SARS-CoV-2 infects retinal cells in an ACE2 dependent manner. These results suggest a direct retinal involvement in COVID-19, and emphasize the need to monitor retinal pathologies as a possible element of “long COVID”.
Project description:Analysis of breast cancer survivors' gut microbiota after lifestyle intervention, during the COVID-19 lockdown, by 16S sequencing of fecal samples.