Similar Datasets
Project description:SARS-CoV-2 RNA generally becomes undetectable in upper airways after a few days or weeks post-infection. It is unclear however if the virus persists in other parts of the body and which mechanism(s) regulate SARS-CoV-2 persistence. We addressed this question in the macaque model. Replication-competent virus was detected in bronchioalveolar lavages (BAL) macrophages beyond 6 months post-infection. SARS-CoV-2 propagated in BAL macrophages from cell-to-cell. IFN-γ inhibited this replication. IFN-γ production within BAL lymphocytes was strongest in NKG2r+CD8+ T and NKG2Alo NK cells and was further increased in NKG2Alo NK cells after Spike protein stimulation. However, IFN-γ production was impaired in NK cells from animals with persisting virus. IFN-γ also enhanced MHC-E expression on BAL macrophages, possibly inhibiting natural killer cell mediated killing. Animals with less persisting virus mounted adaptive NK cells escaping this MHC-E dependent inhibition. Our findings reveal an interplay between NK cells and macrophages mediated by IFN-γ, regulating SARS-CoV-2 persistence in macrophages. Gene expression in bronchoalveolar lavage fluid (BALF) NK cells in SARS-CoV-2 convalescent monkeys.
2023-09-25 | GSE243733 | GEO
Project description:SARS-CoV-2 RNA generally becomes undetectable in upper airways after a few days or weeks post-infection. It is unclear however if the virus persists in other parts of the body and which mechanism(s) regulate SARS-CoV-2 persistence. We addressed this question in the macaque model. Replication-competent virus was detected in bronchioalveolar lavages (BAL) macrophages beyond 6 months post-infection. SARS-CoV-2 propagated in BAL macrophages from cell-to-cell. IFN-γ inhibited this replication. IFN-γ production within BAL lymphocytes was strongest in NKG2r+CD8+ T and NKG2Alo NK cells and was further increased in NKG2Alo NK cells after Spike protein stimulation. However, IFN-γ production was impaired in NK cells from animals with persisting virus. IFN-γ also enhanced MHC-E expression on BAL macrophages, possibly inhibiting natural killer cell mediated killing. Animals with less persisting virus mounted adaptive NK cells escaping this MHC-E dependent inhibition. Our findings reveal an interplay between NK cells and macrophages mediated by IFN-γ, regulating SARS-CoV-2 persistence in macrophages. Gene expression in bronchoalveolar lavage fluid (BALF) NK cells in SARS-CoV-2 convalescent monkeys.
2023-09-25 | GSE243732 | GEO
Project description:SARS-CoV-2 RNA generally becomes undetectable in upper airways after a few days or weeks post-infection. It is unclear however if the virus persists in other parts of the body and which mechanism(s) regulate SARS-CoV-2 persistence. We addressed this question in the macaque model. Replication-competent virus was detected in bronchioalveolar lavages (BAL) macrophages beyond 6 months post-infection. SARS-CoV-2 propagated in BAL macrophages from cell-to-cell. IFN-γ inhibited this replication. IFN-γ production within BAL lymphocytes was strongest in NKG2r+CD8+ T and NKG2Alo NK cells and was further increased in NKG2Alo NK cells after Spike protein stimulation. However, IFN-γ production was impaired in NK cells from animals with persisting virus. IFN-γ also enhanced MHC-E expression on BAL macrophages, possibly inhibiting natural killer cell mediated killing. Animals with less persisting virus mounted adaptive NK cells escaping this MHC-E dependent inhibition. Our findings reveal an interplay between NK cells and macrophages mediated by IFN-γ, regulating SARS-CoV-2 persistence in macrophages. Gene expression in bronchoalveolar lavage fluid (BALF) CD64+ Macrophages isolated from 6 healthy donors, 5 randomly chosen wuhan- and 10 omicron infected cynomolgus macaques at least 221 days post-infection, cultured for 8h and profiled with the NanoString nCounter System.
2023-09-25 | GSE243731 | GEO
Project description:Respiratory infections, like the current COVID-19 pandemic, target epithelial cells in the respiratory tract. Alveolar macrophages (AMs) are tissue-resident macrophages located within the lung. They play a key role in the early phases of an immune response to respiratory viruses. AMs are likely the first immune cells to encounter SARS-CoV-2 during an infection and their reaction to the virus will have a profound impact on the outcome of the infection. Interferons (IFNs) are antiviral cytokines and among the first cytokines produced upon viral infection. In this study, AMs from non-infectious donors are challenged with SARS-CoV-2. We demonstrate that challenged AMs are incapable of sensing SARS-CoV-2 and of producing an IFN response in contrast to other respiratory viruses, like influenza A virus and Sendai virus, which trigger a robust IFN response. The absence of IFN production in AMs upon challenge with SARS-CoV2 could explain the initial asymptotic phase observed during COVID-19 and argues against AMs being the sources of proinflammatory cytokines later during infection.
| S-SCDT-EMBOR-2020-51252V1 | biostudies-other
Project description: Not available
| EMPIAR-10533 | biostudies-other
Project description:Respiratory infections, like the current COVID-19 pandemic, target epithelial cells in the respiratory tract. Alveolar macrophages (AMs) are tissue-resident macrophages located within the lung. They play a key role in the early phases of an immune response to respiratory viruses. AMs are likely the first immune cells to encounter SARS-CoV-2 during an infection, and their reaction to the virus will have a profound impact on the outcome of the infection. Interferons (IFNs) are antiviral cytokines and among the first cytokines produced upon viral infection. In this study, AMs from non-infectious donors are challenged with SARS-CoV-2. We demonstrate that challenged AMs are incapable of sensing SARS-CoV-2 and of producing an IFN response in contrast to other respiratory viruses, like influenza A virus and Sendai virus, which trigger a robust IFN response. The absence of IFN production in AMs upon challenge with SARS-CoV-2 could explain the initial asymptotic phase observed during COVID-19 and argues against AMs being the sources of pro-inflammatory cytokines later during infection.
| S-EPMC7645910 | biostudies-literature
Project description:Lung macrophages are an important defence against respiratory viral infection and recent work has demonstrated that influenza-induced macrophage PDL1 expression in the murine lung leads to rapid modulation of CD8+ T cell responses via the PD1 receptor. This PD1/PDL1 pathway may downregulate acute inflammatory responses to prevent tissue damage. The aim of this study was to investigate the mechanisms of PDL1 regulation by human macrophages in response to viral infection. Ex-vivo viral infection models using influenza and RSV were established in human lung explants, isolated lung macrophages and monocyte-derived macrophages (MDM) and analysed by flow cytometry and RT-PCR. Incubation of lung explants, lung macrophages and MDM with X31 resulted in mean cellular infection rates of 18%, 18% and 29% respectively. Viral infection significantly increased cell surface expression of PDL1 on explant macrophages, lung macrophages and MDM but not explant epithelial cells. Infected MDM induced IFN? release from autologous CD8+ T cells, an effect enhanced by PDL1 blockade. We observed increases in PDL1 mRNA and IFN? mRNA and protein release by MDM in response to influenza infection. Knockdown of IFN? by siRNA, resulted in a 37.5% reduction in IFN? gene expression in response to infection, and a significant decrease in PDL1 mRNA. Furthermore, when MDM were incubated with IFN?, this cytokine caused increased expression of PDL1 mRNA. These data indicate that human macrophage PDL1 expression modulates CD8+ cell IFN? release in response to virus and that this expression is regulated by autologous IFN? production.
| S-EPMC4361055 | biostudies-literature
Project description:Respiratory infections, like the current pandemic SARS-CoV-2 virus, target the epithelial cells in the respiratory tract. However, alveolar macrophages (AMs) are tissue-resident macrophages located within the alveoli of the lung and they play a key role in the early phases of an immune response to respiratory infections. We expect that AMs are the first immune cells to encounter the SARS-CoV-2 and therefore their reaction to SARS-CoV-2 infection will have a profound impact upon the outcome of the infection. Interferons (IFNs) are antiviral cytokines and the first cytokine produced upon viral infection. Here, we challenge AMs with SARS-CoV-2 and to our surprise find that the AMs are incapable of recognising SARS-CoV-2 and produce IFN. This is in contrast to respiratory pathogens, such as influenza A virus and Sendai virus. Callenge of AMs with those viruses resulted in a robust IFN response. The absence of IFN production by AMs upon challenge could explain the initial asymptotic phase of SARS-CoV-2 infections and argues against the AMs as the source of proinflamatory cytokines later in infection.
2020-10-20 | PXD021685 | Pride
Project description:Nontuberculous Mycobacteria (NTM) respiratory infections have been gradually increasing. Here, THP-1 cells were used as a model to evaluate intracellular persistence of three NTM species (reference and clinical strains) in human alveolar macrophages. The contribution of phagosome acidification, nitric oxide (NO) production and cell dead on NTM intracellular fate was assessed. In addition, strains were characterized regarding their repertoire of virulence factors by whole-genome sequencing. NTM experienced different intracellular fates: M. smegmatis and M. fortuitum ATCC 6841 were cleared within 24h. In contrast, M. avium strains (reference/clinical) and M. fortuitum clinical strain were able to replicate. Despite this fact, unexpectedly high percentages of acidified phagosomes were found harbouring rab7, but not CD63. All NTM were able to survive in vitro at acidic pHs, with the exception of M. smegmatis. Our data further suggested a minor role for NO in intracellular persistence and that apoptosis mediated by caspase 8 and 3/7, but not necrosis, is triggered during NTM infection. Insights regarding the bacteria genomic backbone corroborated the virulence potential of M. avium and M. fortuitum. In conclusion, the phenotypic traits detected contrast with those described for M. tuberculosis, pointing out that NTM adopt distinct strategies to manipulate the host immune defense and persist intracellularly.
| S-EPMC6560506 | biostudies-literature
Project description:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invades the alveoli, where abundant alveolar macrophages (AMs) reside. How AMs respond to SARS-CoV-2 invasion remains elusive. Here, we show that classically activated M1 AMs facilitate viral spread; however, alternatively activated M2 AMs limit the spread. M1 AMs utilize cellular softness to efficiently take up SARS-CoV-2. Subsequently, the invaded viruses take over the endo-lysosomal system to escape. M1 AMs have a lower endosomal pH, favoring membrane fusion and allowing the entry of viral RNA from the endosomes into the cytoplasm, where the virus achieves replication and is packaged to be released. In contrast, M2 AMs have a higher endosomal pH but a lower lysosomal pH, thus delivering the virus to lysosomes for degradation. In hACE2 transgenic mouse model, M1 AMs are found to facilitate SARS-CoV-2 infection of the lungs. These findings provide insights into the complex roles of AMs during SARS-CoV-2 infection, along with potential therapeutic targets.
| S-EPMC8043100 | biostudies-literature