scholarly journals Dual-Fluorescence Labeling Pseudovirus for Real-Time Imaging of Single SARS-CoV-2 Entry in Respiratory Epithelial Cells

2021 ◽  
Author(s):  
Yingxin Ma ◽  
Guobin Mao ◽  
Guoqiang Wu ◽  
Minghai Chen ◽  
Fujun Qin ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Real Time ◽  
Fluorescence Labeling ◽  
Dual Fluorescence ◽  
Respiratory Epithelial Cells ◽  
Real Time Imaging ◽  
Respiratory Epithelial

scholarly journals SARS-CoV-2 drives JAK1/2-dependent local complement hyperactivation

2021 ◽  
Vol 6 (58) ◽  
pp. eabg0833
Author(s):  
Bingyu Yan ◽  
Tilo Freiwald ◽  
Daniel Chauss ◽  
Luopin Wang ◽  
Erin West ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Clinical Manifestations ◽  
Lung Epithelial Cells ◽  
Complement Factor ◽  
Respiratory Epithelial Cells ◽  
Signature Genes ◽  
Wide Range ◽  
Lung Epithelial ◽  
Gene Transcripts ◽  
Respiratory Epithelial

Patients with coronavirus disease 2019 (COVID-19) present a wide range of acute clinical manifestations affecting the lungs, liver, kidneys and gut. Angiotensin converting enzyme (ACE) 2, the best-characterized entry receptor for the disease-causing virus SARS-CoV-2, is highly expressed in the aforementioned tissues. However, the pathways that underlie the disease are still poorly understood. Here, we unexpectedly found that the complement system was one of the intracellular pathways most highly induced by SARS-CoV-2 infection in lung epithelial cells. Infection of respiratory epithelial cells with SARS-CoV-2 generated activated complement component C3a and could be blocked by a cell-permeable inhibitor of complement factor B (CFBi), indicating the presence of an inducible cell-intrinsic C3 convertase in respiratory epithelial cells. Within cells of the bronchoalveolar lavage of patients, distinct signatures of complement activation in myeloid, lymphoid and epithelial cells tracked with disease severity. Genes induced by SARS-CoV-2 and the drugs that could normalize these genes both implicated the interferon-JAK1/2-STAT1 signaling system and NF-κB as the main drivers of their expression. Ruxolitinib, a JAK1/2 inhibitor, normalized interferon signature genes and all complement gene transcripts induced by SARS-CoV-2 in lung epithelial cell lines, but did not affect NF-κB-regulated genes. Ruxolitinib, alone or in combination with the antiviral remdesivir, inhibited C3a protein produced by infected cells. Together, we postulate that combination therapy with JAK inhibitors and drugs that normalize NF-κB-signaling could potentially have clinical application for severe COVID-19.

scholarly journals Lycopene Inhibits Toll-Like Receptor 4-Mediated Expression of Inflammatory Cytokines in House Dust Mite-Stimulated Respiratory Epithelial Cells

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3127
Author(s):  
Jiyeon Choi ◽  
Joo Weon Lim ◽  
Hyeyoung Kim
Keyword(s):  
Epithelial Cells ◽  
A549 Cells ◽  
Cytokine Expression ◽  
Ros Production ◽  
Toll Like Receptor ◽  
Respiratory Epithelial Cells ◽  
Toll Like Receptor 4 ◽  
Mitochondrial Ros ◽  
Tlr4 Activation ◽  
Respiratory Epithelial

House dust mites (HDM) are critical factors in airway inflammation. They activate respiratory epithelial cells to produce reactive oxygen species (ROS) and activate Toll-like receptor 4 (TLR4). ROS induce the expression of inflammatory cytokines in respiratory epithelial cells. Lycopene is a potent antioxidant nutrient with anti-inflammatory activity. The present study aimed to investigate whether HDM induce intracellular and mitochondrial ROS production, TLR4 activation, and pro-inflammatory cytokine expression (IL-6 and IL-8) in respiratory epithelial A549 cells. Additionally, we examined whether lycopene inhibits HDM-induced alterations in A549 cells. The treatment of A549 cells with HDM activated TLR4, induced the expression of IL-6 and IL-8, and increased intracellular and mitochondrial ROS levels. TAK242, a TLR4 inhibitor, suppressed both HDM-induced ROS production and cytokine expression. Furthermore, lycopene inhibited the HDM-induced TLR4 activation and cytokine expression, along with reducing the intracellular and mitochondrial ROS levels in HDM-treated cells. These results collectively indicated that the HDM induced TLR4 activation and increased intracellular and mitochondrial ROS levels, thus resulting in the induction of cytokine expression in respiratory epithelial cells. The antioxidant lycopene could inhibit HDM-induced cytokine expression, possibly by suppressing TLR4 activation and reducing the intracellular and mitochondrial ROS levels in respiratory epithelial cells.

scholarly journals Dolosigranulum pigrum Modulates Immunity against SARS-CoV-2 in Respiratory Epithelial Cells

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 634
Author(s):  
Md. Aminul Islam ◽  
Leonardo Albarracin ◽  
Vyacheslav Melnikov ◽  
Bruno G. N. Andrade ◽  
Rafael R. C. Cuadrat ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Specific Effect ◽  
Commensal Bacteria ◽  
Cellular Damage ◽  
Poly I:C ◽  
Respiratory Epithelial Cells ◽  
Promising Alternative ◽  
Immunological Mechanisms ◽  
Syncytial Virus ◽  
Respiratory Epithelial

In a previous work, we demonstrated that nasally administered Dolosigranulum pigrum 040417 beneficially modulated the respiratory innate immune response triggered by the activation of Toll-like receptor 3 (TLR3) and improved protection against Respiratory Syncytial Virus (RSV) in mice. In this work, we aimed to evaluate the immunomodulatory effects of D. pigrum 040417 in human respiratory epithelial cells and the potential ability of this immunobiotic bacterium to increase the protection against Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The respiratory commensal bacterium D. pigrum 040417 differentially modulated the production of IFN-β, IL-6, CXCL8, CCL5 and CXCL10 in the culture supernatants of Calu-3 cells stimulated with poly(I:C) or challenged with SARS-CoV-2. The differential cytokine profile induced by the 040417 strain was associated with a significant reduction in viral replication and cellular damage after coronavirus infection. Of note, D. pigrum 030918 was not able to modify the resistance of Calu-3 cells to SARS-CoV-2 infection, indicating a strain-specific immunomodulatory effect for respiratory commensal bacteria. The findings of this work improve our understanding of the immunological mechanisms involved in the modulation of respiratory immunity induced by respiratory commensal bacteria, by demonstrating their specific effect on respiratory epithelial cells. In addition, the results suggest that particular strains such as D. pigrum 040417 could be used as a promising alternative for combating SARS-CoV-2 and reducing the severity of COVID-19.

Intranasal Toxicity of BMS-181885, A Novel 5-HT1 Agonist

1999 ◽  
Vol 18 (5) ◽  
pp. 285-296
Author(s):  
Gene E. Schulze ◽  
Jim E. Proctor ◽  
Mark A. Dominick ◽  
Amy E. Weiss ◽  
Oliver P. Flint ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Nasal Mucosa ◽  
Olfactory Epithelium ◽  
Mucosal Injury ◽  
Separate Experiment ◽  
Toxic Metabolite ◽  
Respiratory Epithelial Cells ◽  
Nasal Injury ◽  
Respiratory Epithelial ◽  
Dose Dependent

One-month intranasal toxicity studies were conducted with BMS-181885 at doses of 1.5, 9, or 15 mg/animal/day in rats and 4, 24, or 40 mg/animal/day in monkeys. A 1-month intermittent intranasal toxicity study was also conducted in monkeys at doses of 3, 6, and 12 mg/animal 3 days per week. BMS-181885 was generally well tolerated in rats but resulted in dose-dependent nasal mucosal injury, primarily characterized by subacute inflammation of the nasal mucosa, and degeneration, single-cell necrosis, and/or erosion of the olfactory epithelium and, to a lesser extent, the respiratory epithelium. In monkeys, daily BMS-181885 administration was well tolerated and produced similar dose-dependent nasal injury primarily characterized by subacute inflammation of the nasal mucosa with degeneration and erosion of the olfactory epithelium. In a separate experiment, intermittent administration also resulted in dose-dependent nasal injury. In cultured rat nasal mucosal cells, BMS-181885 was toxic to olfactory epithelial cells with a range of mean IC50s between 44 and 291 μM. In contrast, BMS-181885 had no effect on respiratory epithelial cells up to its maximum solubility. Cytochrome P450 inhibition had no effect on the toxicity of BMS-181885 in olfactory epithelial cells but produced dose-dependent toxicity in respiratory epithelial cells, which was not present previously. The in vitro data suggest that parent drug, rather than a toxic metabolite, caused the drug-associated nasal mucosal injury.

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