Measurement of SARS-CoV-2 variants fraction in infected alveolar cells
Ontology highlight
ABSTRACT:
PROVIDER: EGAS00001006730 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:This study explores the interaction between various SARS-CoV-2 variants and host cells by using RNA sequencing (RNA-seq) of human airway epithelial cells. The primary objective was to elucidate the host cellular responses, including metabolic and immune pathways, to different SARS-CoV-2 variants. Human airway epithelial cells were infected with SARS-CoV-2 variants (IC19, Alpha, Beta, Delta, Omicron BA.1, and BA.5) and compared with mock samples at time 0. Samples were collected at 24 and 72 hours post-infection for RNA isolation and subsequent bulk RNA-sequencing. The RNA-seq data processing involved quality checks, mapping reads to a reference genome, and identifying differentially expressed genes to determine changes in gene expression in response to viral infection. This analysis aims to provide a deeper understanding of the molecular interactions between SARS-CoV-2 variants and host cells, contributing to the broader knowledge of viral pathogenicity and host-pathogen interactions.
2025-07-01 | GSE271378 | GEO
Project description:The ancestral SARS-CoV-2 strain that initiated the Covid-19 pandemic at the end of 2019 has rapidly mutated into multiple variants of concern with variable pathogenicity and increasing immune escape strategies. However, differences in host cellular antiviral responses upon infection with SARS-CoV-2 variants remains elusive. Leveraging whole cell proteomics, we determined host signalling pathways that are differentially modulated upon infection with the clinical isolates of the ancestral SARS-CoV-2 B.1 and the variants of concern Delta and Omicron BA.1. Our findings illustrate alterations in the global host proteome landscape upon infection with SARS-CoV-2 variants and the resulting host immune responses. Additionally, viral proteome kinetics reveal declining levels of viral protein expression during Omicron BA.1 infection when compared to ancestral B.1 and Delta variants, consistent with its reduced replication rates. Moreover, molecular assays reveal deferral activation of specific host antiviral signalling upon Omicron BA.1 and BA.2 infection. Our study provides an overview of host proteome profile of multiple SARS-CoV-2 variants and brings forth a better understanding of the instigation of key immune signalling pathways causative for the differential pathogenicity of SARS-CoV-2 variants.
2023-05-10 | PXD037265 | Pride
Project description:Spanning August 2020 to July 2022, this model reconstructs SARS-CoV-2 infection and reinfection dynamics across multiple variants — mainly wildtype, Alpha, Delta, and Omicron BA.4/5. It describes how each variant spread through the population, incorporating cross-immunity between variants. The model is calibrated using seroprevalence data, PCR positivity rates, and variant sequencing, providing insights into how prior infections shaped susceptibility to future waves.
2025-04-12 | MODEL2504120001 | BioModels
Project description:SARS-CoV-2 induces widespread transcriptomic changes in host cells upon infection, in part through activation and modulation of innate immunity pathways and downstream gene regulation. However, the mechanisms by which SARS-CoV-2 and its evolutionary variants differentially affect host cell transcriptomic states remain largely unclear. Through chromatin proteomic (iDAPT-MS) analysis, we found that although SARS-CoV-2 and other pathogenic coronaviruses exhibit similar proteomic shifts on chromatin, SARS-CoV-2 uniquely promotes TP53 nuclear accumulation and activation. Parallel assessment of SARS-CoV-2 viral protein expression on host chromatin states (ATAC-seq) identifies intracellular spike protein as a key determinant of virus-mediated chromatin accessibility changes. Multilevel chromatin profiling reveals increased TP53 nuclear accumulation, TP53-associated chromatin accessibility changes, and TP53 target gene activation upon expression of SARS-CoV-2 alpha (B.1.1.7) and delta (B.1.617.2) spike variants relative to the ancestral spike sequence. TP53, ACE2, and furin cleavage are required for these changes, driving decreased cellular proliferation, increased cellular senescence, and increased cytokine release. Finally, BA.1 but not BA.2, BA.2.12.1, nor BA.4/BA.5 spike expression leads to attenuated TP53 activity and fusogenicity relative to ancestral spike. Our findings implicate spike-mediated host TP53 activation as a “rheostat” of COVID-19 pathogenicity.
2023-09-09 | PXD034648 | Pride
Project description:The Coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a global threat, exacerbated by the emergence of viral variants. Two variants of SARS-CoV-2, Omicron BA.2.75 and BA.5, led to global infection peaks between May 2022 and May 2023, yet their precise characteristics in pathogenesis are not well understood. In this study, we compared these two Omicron sublineages with the previously dominant Delta variant using a human angiotensin-converting enzyme 2 knock-in mouse model. As expected, Delta exhibited higher viral replication in the lung and brain than both Omicron sublineages which induced less severe lung damage and immune activation. In contrast, the Omicron variants especially BA.5.2 showed a propensity for cellular proliferation and developmental pathways. Both Delta and BA.5.2 variants, but not BA.2.75, led to decreased pulmonary lymphocytes, indicating differential adaptive immune response. Neuroinvasiveness was shared with all strains, accompanied by vascular abnormalities, synaptic injury, and loss of astrocytes. However, Immunostaining assays and transcriptomic analysis showed that BA.5.2 displayed stronger immune suppression and neurodegeneration, while BA.2.75 exhibited more similar characteristics to Delta in the cortex. Such differentially infectious features could be partially attributed to the weakened interaction between Omicron Spike protein and host proteomes decoded via co-immunoprecipitation followed by mass spectrometry in neuronal cells. Our present study supports attenuated replication and pathogenicity of Omicron variants but also highlights their newly infectious characteristics in the lung and brain, especially with BA.5.2 demonstrating enhanced immune evasion and neural damage that could exacerbate neurological sequelae.
2025-04-17 | GSE234799 | GEO
Project description:Omicron is currently the dominant SARS-CoV-2 variant and several sublineages have emerged. Questions remain about the impact of previous SARS-CoV-2 exposure on cross-variant immune responses elicited by the SARS-CoV-2 Omicron sublineage BA.2 compared to BA.1. Here we show that without previous history of COVID-19, BA.2 infection induces a reduced immune response against all variants of concern (VOC) compared to BA.1 infection. The absence of ACE2 binding in sera of previously naïve BA.1 and BA.2 patients indicates a lack of meaningful neutralization. In contrast, anti-spike antibody levels and neutralizing activity greatly increased in the BA.1 and BA.2 patients with a previous history of COVID-19. Transcriptome analyses of peripheral immune cells showed significant differences in immune response and specific antibody generation between BA.1 and BA.2 patients as well as significant differences in the expression of specific immune genes. In summary, prior infection status significantly impacts the innate and adaptive immune response against VOC following BA.2 infection.
2022-12-20 | GSE205244 | GEO
Project description:Vaccine-induced immunity may impact subsequent de novo responses to drifted epitopes in SARS-CoV-2 variants, but this has been difficult to quantify due to the challenges in recruiting unvaccinated control groups whose first exposure to SARS-CoV-2 is a primary infection . Through local, statewide, and national SARS-CoV-2 testing programs, we were able to recruit cohorts of individuals who had recovered from either primary or post-vaccination infections by either the Delta or Omicron BA.1 variants. Regardless of variant, we observed greater Spike-specific and neutralizing antibody responses in post-vaccination infections than in those who were infected without prior vaccination. Through analysis of variant-specific memory B cells as markers of de novo responses, we observed that Delta and Omicron BA.1 infections led to a marked shift in immunodominance in which some drifted epitopes elicited minimal responses, even in primary infections. Prior immunity through vaccination had a small negative impact on these de novo responses, but this did not correlate with cross-reactive memory B cells, arguing against competitive inhibition of naïve B cells. We conclude that dampened de novo B cell responses against drifted epitopes are mostly a function of altered immunodominance hierarchies that are apparent even in primary infections, with a more modest contribution from pre-existing immunity, perhaps due to accelerated antigen clearance.
2023-09-12 | GSE242775 | GEO
Project description:SARS-CoV-2 variants have been involved in various waves of the COVID19 pandemic and showed different pathogenicity and inflammatory potential. Whether they can induce different patterns of innate immune activation in antigen-presenting cells is poorly understood. Here, we investigated the ability of primary plasmacytoid pre-dendritic cells (pDC), type 2 dendritic cells (DC2), and monocytes isolated from healthy blood donors to respond to SARS-CoV-2 variants. Transcriptomic profiling using RNA sequencing revealed that pDC respond differentially to SARS-CoV-2 variants, while DC2 and monocytes do not. Functional studies showed that pDC undergo differential activation programs upon SARS-CoV-2 variant stimulation. The Alpha B220/95 and Delta variants induced P1-/P2-pDC effector phenotypes, characterized by strong IFN-α production. On the contrary, BA.1 variant turned pDC into a predominant T cell activating P3 phenotype, with less IFN-α and IFN-λ production, and stronger proinflammatory and CD4+T cell responses. Our results indicate that pDC activation and diversification pattern can be differentially controlled by SARS-CoV-2 variants, which may influence disease severity
2025-06-01 | GSE294888 | GEO
Project description:To investigate the virological properties of SARS-CoV-2 variants, we amplified the clinical isolates of an early pandemic D614G-bearing isolate (B.1.1 lineage, strain TKYE610670; GISAID ID: EPI_ISL_479681), a Delta isolate (B.1.617.2 lineage, strain TKYTK1734; GISAID ID: EPI_ISL_2378732) and an Omicron isolate (BA.1 lineage, strain TY38-873; GISAID ID: EPI_ISL_7418017) and prepared the working viruses.
2022-01-07 | GSE192472 | GEO
Project description:The Coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a global threat, exacerbated by the emergence of viral variants. Two recent variants of SARS-CoV-2, Omicron BA.2.75 and BA.5, have been reported globally, yet their precise characteristics are not well understood. In this study, we compared these two Omicron sub-lineages with the previously dominant Delta variant using a hACE2 knock-in mouse model. As expected, Delta exhibited higher viral replication in the lung and brain than both Omicron sub-lineages that induced less severe lung damage and immune activation. In contrast, the Omicron variants especially BA.5 showed a propensity for cellular proliferation and developmental pathways. Both Delta and BA.5 variants, but not BA.2.75, led to decreased pulmonary lymphocytes, indicating differential adaptive immune response. Neuroinvasiveness was shared with all strains, accompanied by vascular abnormalities, synaptic injury, and loss of astrocytes. However, Immunostaining assays and transcriptomic analysis showed that BA.5 displayed stronger immune suppression and neurodegeneration, while BA.2.75 exhibited more similar characteristics to Delta in the cortex. Such differentially infectious features could be partially attributed to the weakened interaction between Omicron Spike protein and host proteomes decoded via co-immunoprecipitation followed by mass spectrometry in neuronal cells. Our present study supports attenuated replication and pathogenicity of Omicron variants but also highlights their newly infectious characteristics in the lung and brain, especially with BA.5 demonstrating enhanced immune evasion and neural damage that could exacerbate neurological sequelae.
2023-06-09 | PXD042841 |