scholarly journals SARS-CoV-2 activates lung epithelia cell proinflammatory signaling and leads to immune dysregulation in COVID-19 patients by single-cell sequencing

Author(s):  
Huarong Chen ◽  
Weixin Liu ◽  
Dabin Liu ◽  
Liuyang Zhao ◽  
Jun Yu

Objective: The outbreak of Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection has become a global health emergency. We aim to decipher SARS-CoV-2 infected cell types, the consequent host immune response and their interplay in the lung of COVID-19 patients. Design: We analyzed single-cell RNA sequencing (scRNA-seq) data of lung samples from 17 subjects (6 severe COVID-19 patients, 3 mild patients who recovered and 8 healthy controls). The expression of SARS-CoV-2 receptors (ACE2 and TMPRSS2) was examined among different cell types in the lung. The immune cells infiltration patterns, their gene expression profiles, and the interplay of immune cells and SARS-CoV-2 target cells were further investigated. Results: Compared to healthy controls, the overall ACE2 (receptor of SARS-CoV-2) expression was significantly higher in lung epithelial cells of COVID-19 patients, in particular in ciliated cell, club cell and basal cell. Comparative transcriptome analysis of these lung epithelial cells of COVID-19 patients and healthy controls identified that SARS-CoV-2 infection activated pro-inflammatory signaling including interferon pathway and cytokine signaling. Moreover, we identified dysregulation of immune response in patients with COVID-19. In severe COVID-19 patients, significantly higher neutrophil, but lower T and NK cells in lung were observed along with markedly increased cytokines (CCL2, CCL3, CCL4, CCL7, CCL3L1 and CCL4L2) compared with healthy controls as well as mild patients who recovered. The cytotoxic phenotypes were shown in lung T and NK cells of severe patients as evidenced by enhanced IFNγ, Granulysin, Granzyme B and Perforin expression. Moreover, SARS-CoV-2 infection altered the community interplay of lung epithelial cells and immune cells: the interaction between epithelial cells with macrophage, T and NK cell was stronger, but their interaction with neutrophils was lost in COVID-19 patients compared to healthy controls. Conclusions: SARS-CoV-2 infection activates pro-inflammatory signaling in lung epithelial cells expressing ACE2 and causes dysregulation of immune response to release more pro-inflammatory cytokines. Moreover, SARS-CoV-2 infection breaks the interplay of lung epithelial cells and immune cells.

2021 ◽  
Author(s):  
Tao Zhu ◽  
Anthony P Brown ◽  
Lucy Cai ◽  
Gerald Quon ◽  
Hong Ji

Background: Tet1 protects against house dust mite (HDM)-induced lung inflammation in mice and alters the lung methylome and transcriptome. We explored the role of Tet1 in individual lung epithelial cell types in HDM-induced inflammation. Methods: A model of HDM-induced lung inflammation was established in Tet1 knockout and littermate wildtype mice. EpCAM+ lung epithelial cells were isolated. Libraries were generated using the 10X Chromium workflow and sequenced. ScRNA-seq analysis was performed using Cell Ranger, scAlign, and Seurat. Cell types were labeled using known markers. Enriched pathways were identified using Ingenuity Pathway Analysis. Transcription factor (TF) activity was analyzed by DoRothEA. Single-cell trajectory analysis was performed with Monocle to explore Alveolar type 2 (AT2) cell differentiation. Results: AT2 cells were the most abundant among the eight EpCAM+ lung epithelial cell types. HDM challenge increased the percentage of alveolar progenitor cells (AP), broncho alveolar stem cells (BAS), and goblet cells, and decreased the percentage of AT2 and ciliated cells. Bulk and cell-type-specific analysis identified genes subject to Tet1 regulation and linked to augmented lung inflammation, including alarms, detoxification enzymes and oxidative stress response genes, and gene in tissue repair. The transcriptomic regulation was accompanied by alterations in TF activities. Trajectory analysis supports that HDM may enhance the differentiation of AP and BAS cells into AT2 cells, independent of Tet1. Conclusions: Collectively, lung epithelial cells had common and unique transcriptomic signatures of allergic lung inflammation. Tet1 deletion altered transcriptomic networks in various lung epithelial cells, with an overall effect of promoting allergen-induced lung inflammation.


2020 ◽  
Author(s):  
Jiurong Liang ◽  
Guanling Huang ◽  
Xue Liu ◽  
Forough Taghavifar ◽  
Ningshan Liu ◽  
...  

ABSTRACTAging is a critical risk factor in progressive lung fibrotic diseases such as idiopathic pulmonary fibrosis (IPF). Loss of integrity of type 2 alveolar epithelial cells (AEC2s) is the main causal event in the pathogenesis of IPF. To systematically examine the genomic program changes of AEC2s with aging and lung injury, we performed unbiased single cell RNA-seq analyses of lung epithelial cells from either uninjured or bleomycin-injured young and old mice. Major lung epithelial cell types were readily identified with canonical cell markers in our dataset. Heterogenecity of AEC2s was apparent, and AEC2s were then classified into three subsets according to their gene signatures. Genes related to lipid metabolism and glycolysis were significantly altered within these three clusters of AEC2s, and also affected by aging and lung injury. Importantly, IPF AEC2s showed similar genomic programming and metabolic changes as that of AEC2s from bleomycin injured old mouse lungs relative to controls. Furthermore, perturbation of both lipid metabolism and glycolysis significantly changed progenitor renewal capacity in 3-Demensional organoid culture of AEC2s. Taken togather, this work identified metabolic defects of AEC2s in aging and during lung injury. Strategies to rectify these altered programs would promote AEC2 renewal which in turn improves lung repair.One sentence summaryMetabolic defects of alveolar progenitors in aging and during lung injury impair their renewal.


2020 ◽  
Author(s):  
Yinfang Wang ◽  
Yingzhe Fan ◽  
Yitong Huang ◽  
Tao Du ◽  
Zongjun Liu ◽  
...  

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19), it binds to angiotensin-converting enzyme 2 (ACE2) to enter into human cells. The expression level of ACE2 potentially determine the susceptibility and severity of COVID-19, it is thus of importance to understand the regulatory mechanism of ACE2 expression. Tripartite motif containing 28 (TRIM28) is known to be involved in multiple processes including antiviral restriction, endogenous retrovirus latency and immune response, it is recently reported to be co-expressed with SARS-CoV-2 receptor in type II pneumocytes; however, the roles of TRIM28 in ACE2 expression and SARS-CoV-2 cell entry remain unclear. This study showed that knockdown of TRIM28 induces ACE2 expression and increases pseudotyped SARS-CoV-2 cell entry of A549 cells and primary pulmonary alveolar epithelial cells (PAEpiCs). In a co-culture model of NK cells and lung epithelial cells, our results demonstrated that NK cells inhibit TRIM28 and promote ACE2 expression in lung epithelial cells, which was partially reversed by depletion of interleukin-2 and blocking of granzyme B in the co-culture medium. Furthermore, TRIM28 knockdown enhanced interferon-γ (IFN-γ)-induced ACE2 expression through a mechanism involving upregulating IFN-γ receptor 2 (IFNGR2) in both A549 and PAEpiCs. Importantly, the upregulated ACE2 induced by TRIM28 knockdown and co-culture of NK cells was partially reversed by dexamethasone in A549 cells but not PAEpiCs. Our study identified TRIM28 as a novel regulator of ACE2 expression and SARS-CoV-2 cell entry.


Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1975 ◽  
Author(s):  
Daria Bortolotti ◽  
Valentina Gentili ◽  
Sabrina Rizzo ◽  
Antonella Rotola ◽  
Roberta Rizzo

Natural killer cells are important in the control of viral infections. However, the role of NK cells during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has previously not been identified. Peripheral blood NK cells from SARS-CoV and SARS-CoV-2 naïve subjects were evaluated for their activation, degranulation, and interferon-gamma expression in the presence of SARS-CoV and SARS-CoV-2 spike proteins. K562 and lung epithelial cells were transfected with spike proteins and co-cultured with NK cells. The analysis was performed by flow cytometry and immune fluorescence. SARS-CoV and SARS-CoV-2 spike proteins did not alter NK cell activation in a K562 in vitro model. On the contrary, SARS-CoV-2 spike 1 protein (SP1) intracellular expression by lung epithelial cells resulted in NK cell-reduced degranulation. Further experiments revealed a concomitant induction of HLA-E expression on the surface of lung epithelial cells and the recognition of an SP1-derived HLA-E-binding peptide. Simultaneously, there was increased modulation of the inhibitory receptor NKG2A/CD94 on NK cells when SP1 was expressed in lung epithelial cells. We ruled out the GATA3 transcription factor as being responsible for HLA-E increased levels and HLA-E/NKG2A interaction as implicated in NK cell exhaustion. We show for the first time that NK cells are affected by SP1 expression in lung epithelial cells via HLA-E/NKG2A interaction. The resulting NK cells’ exhaustion might contribute to immunopathogenesis in SARS-CoV-2 infection.


2021 ◽  
Author(s):  
Sinem Tas ◽  
Emil Rehnberg ◽  
Deniz A. Bölükbaş ◽  
Jason P. Beech ◽  
Liora Nasi Kazado ◽  
...  

Mechanical ventilation is often required in patients with pulmonary disease to maintain adequate gas exchange. Despite improved knowledge regarding the risks of over ventilating the lung, ventilator induced lung injury (VILI) remains a major clinical problem due to inhomogeneities within the diseased lung itself as well as the need to increase pressure or volume of oxygen to the lung as a life-saving measure. VILI is characterized by increased physical forces exerted within the lung, which results in cell death, inflammation and long-term fibrotic remodeling. Animal models can be used to study VILI, but it is challenging to distinguish the contributions of individual cell types in such a setup. In vitro models, which allow for controlled stretching of specific lung cell types have emerged as a potential option, but these models and the membranes used in them are unable to recapitulate some key features of the lung such as the 3D nanofibrous structure of the alveolar basement membrane while also allowing for cells to be cultured at an air liquid interface (ALI) and undergo increased mechanical stretch that mimics VILI. Here we develop a lung on a chip device with a nanofibrous synthetic membrane to provide ALI conditions and controllable stretching, including injurious stretching mimicking VILI. The lung on a chip device consists of a thin (i.e. ~20 μm) stretchable poly(caprolactone) (PCL) nanofibrous membrane placed between two channels fabricated in polydimethylsiloxane (PDMS) using 3D printed molds. We demonstrate that this lung on a chip device can be used to induce mechanotrauma in lung epithelial cells due to cyclic pathophysiologic stretch (~25%) that mimics clinical VILI. Pathophysiologic stretch induces cell injury and subsequently cell death, which results in loss of the epithelial monolayer, a feature mimicking the early stages of VILI. We also validate the potential of our lung on a chip device to be used to explore cellular pathways known to be altered with mechanical stretch and show that pathophysiologic stretch of lung epithelial cells causes nuclear translocation of the mechanotransducers YAP/TAZ. In conclusion, we show that a breathable lung on a chip device with a nanofibrous membrane can be easily fabricated using 3D printing of the lung on a chip molds and that this model can be used to explore pathomechanisms in mechanically induced lung injury.


Author(s):  
Daria Bortolotti ◽  
Valentina Gentili ◽  
Sabrina Rizzo ◽  
Antonella Rotola ◽  
Roberta Rizzo

Abstract Natural killer (NK) cells are important in the control of viral infections. However, the role of NK cells during Sars-Cov-2 infection has previously not been identified. Peripheral blood NK cells from Sars-Cov and Sars-Cov-2 naïve subjects were evaluated for their activation, degranulation, interferon-gamma expression in the presence of Sars-Cov and Sars-Cov-2 spike proteins. K562 and lung epithelial cells were transfected with spike proteins and co-cultured with NK cells. The analysis was performed by flow cytometry and immune-fluorescence. Sars-Cov and Sars-Cov-2 spike proteins did not alter NK cell activation in K562 in vitro model. On the contrary, Sars-Cov-2 spike 1 protein (SP1) intracellular expression by lung epithelial cells resulted in NK cell reduced degranulation. Further experiments revealed a concomitant induction of HLA-E expression on the surface of lung epithelial cells and the recognition of a SP1-derived HLA-E-binding peptide. Simultaneously, there was the up-modulation of the inhibitory receptor NKG2A/CD94 on NK cells when SP1 is expressed in lung epithelial cells. We ruled out GATA3 transcription factor as responsible for HLA-E increased levels and HLA-E/NKG2A interaction as implicate in NK cells exhaustion. We show for the first time that NK cells are affected by SP1 expression in lung epithelial cells via HLA-E/NKG2A interaction. The resulting NK cells exhaustion might contribute to immunopathogenesis in Sars-Cov-2 infection.


Author(s):  
Miao Jiang ◽  
Pekka Kolehmainen ◽  
Laura Kakkola ◽  
Sari Maljanen ◽  
Krister Melén ◽  
...  

With the rapid spread of the coronavirus disease 2019 (COVID-19) pandemic, information on the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and regulation of innate immunity in human immune cells and lung epithelial cells is needed. In the present study, we show that SARS-CoV-2 failed to productively infect human immune cells, but different isolates of SARS-CoV-2 showed differential ability to replicate and regulate innate interferon responses in human lung epithelial Calu-3 cells.


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