Project description:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes Coronavirus disease 2019 (COVID-19) has caused a global health emergency. A key feature of COVID-19 is dysregulated Interferon-response. Type-I interferon (IFN-I) is one of the earliest antiviral innate immune responses following viral infection and plays a significant role in pathogenesis of SARS-CoV-2. In this study, using a proteomics-based approach, we identified that SARS-CoV-2 infection induces delayed and dysregulated IFN-I signaling in Huh7 cells. We demonstrate that SARS-CoV-2 is able to inhibit RIG-I mediated IFN- production. Our results also confirm the recent findings that IFN-I pretreatment is able to reduce susceptibility of Huh7 cells to SARS-CoV-2, but not post-treatment. Senescent Huh7 cells in spite of showing accentuated IFN-I response were more susceptible to SARS-CoV-2 infection and SARS-CoV-2 effectively inhibited IFIT1 in these cells. Proteomic comparison between SARS-CoV-2, SARS-CoV and MERS-CoV revealed a distinct differential regulatory signature of interferon-related proteins emphasizing that therapeutic strategies based on observations in SARS-CoV and MERS-CoV should be used with caution. Our findings provide a better understanding of SARS-CoV-2 regulation of cellular interferon response and a perspective on its use as a treatment. Characterization of the role of different interferon stimulated genes on the inhibition of SARS-CoV-2 pathogenesis may direct novel antiviral strategies.
Project description:We have genotyped 140 individuals from 5 populations in Pakistan, using the OmniExpressExome-8 array, which includes approximately one million autosomal SNP markers.
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:Ground water Arsenic (As) toxicity is a global problem and millions of people are exposed to elevated levels (more than WHO advised maximum limit of 10µg/L) through drinking water. The exposure is associated with various cancerous and non-cancerous diseases. It may alter DNA methylation profiles of inviduals and suppress the activity of various genes giving rise to different diseases. Pakistan, a developing country in South Asian region, also has reported elevated ground water As levels in various investigations since 2005. However, a very limited biomonitoring studies have been conducted in this context while no study reports molecular changes associated with drinking water As exposure in Pakistan. Within this context, the present study aimed to investigate genome-wide DNA methylation profiles of the exposed subjects in two districts of Punjab Province Pakistan, i.e Lahore and Kasur. The population was stratified into three exposure groups comprising Low, Medium and High exposure based on their urinary arsenic levels. Genome-wide DNA methylation profiles were obtained using MeDIP in combination with NimbleGen 2.1M Deluxe Promotor arrays.
Project description:SARS-CoV-2, the coronavirus behind the ongoing pandemic, manifests itself in a broad array of symptoms involving various body organs, such as lungs, intestine, kidneys, heart, liver, and brain. To investigate how SARS-CoV-2 navigates disparate organs and alters their biology, we engineered a panel of phenotypically diverse human cell lines representing different organs that support efficient virus infection. We leveraged these infection models to profile tissue-specific host responses to SARS-CoV-2 infection by global proteomic analyses. This uncovered broad as well as cell type-specific perturbations of cellular proteins, several of which we subsequently validated by an orthogonal approach. Our detailed follow-up investigation of a number of proteins in different cell types, including a stem cell-derived model of virus infection, revealed almost complete desensitization of SARS-CoV-2-infected cells to interferon treatment. These findings elucidate the immune evasion mechanisms of SARS-CoV-2 and have implications for the currently evaluated antiviral regimens involving interferon (148).
Project description:SARS-CoV-2 infection activates interferon-controlled signaling pathways and elicits a wide spectrum of immune responses and clinical manifestations in human patients. Here, we investigate the impact of prior vaccination on the innate immune response of hospitalized COVID-19 patients infected with the SARS-CoV-2 Beta variant through RNA sequencing of peripheral blood immune cells. Four patients had received the first dose of BNT162b2 about 11 days prior to the onset of COVID-19 symptoms and five patients were unvaccinated. Patients had received dexamethasone treatment. Immune transcriptomes were obtained at days 7-13, 20-32 and 42-60 after first symptomology. RNA-seq reveals an enhanced JAK-STAT-mediated immune transcriptome response at day 10 in vaccinated patients as compared to unvaccinated ones. This increase subsides by day 35. Expression of the gene encoding the antiviral protein oligoadenylate synthetase (OAS) 1, which is inversely correlated with disease severity, and other key antiviral proteins increases in the vaccinated group. We also investigate the immune transcriptome in naïve individuals receiving their first dose of BNT162b2 and identify a gene signature shared with the vaccinated COVID-19 patients. Our study demonstrates that RNA-seq can be used to monitor molecular immune responses elicited by the BNT162b2 vaccine, both in naïve individuals and in COVID-19 patients, and it provides a biomarker-based approach to systems vaccinology.
Project description:Infection with SARS-CoV-2 in pregnancy has been associated with poor maternal and neonatal outcomes and placental defects. The placenta, which acts as a physical and immunological barrier at the maternal/fetal interface, is not established until the end of the first trimester. Therefore, localized viral infection of the trophoblast compartment early in gestation could trigger an inflammatory response resulting in altered placental function and consequent suboptimal conditions for fetal growth and development. In this study, we investigated the effect of SARS-CoV-2 infection in early gestation placentae using placenta-derived human trophoblast stem cells (TSC), a novel in vitro model, and their extra-villous trophoblast (EVT) and syncytiotrophoblast (STB) derivatives. Consistent with host viral entry protein expression, SARS-CoV-2 was able to productively replicate in TSC-derived STB and EVT but not undifferentiated TSC. Both early EVT and STB elicited an interferon-mediated innate immune response similar to other cells infected with this virus. Therefore, we have also shown that placenta derived TSCs are a robust in vitro model to investigate the effect of this viral infection in the trophoblast compartment of the early placenta. Overall, these results suggest that SARS-CoV-2 infection in early gestation can adversely affect placental development and that might occur via directly infecting the differentiated trophoblast compartment, thus posing a higher risk for poor pregnancy outcomes.