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1.
Proc Natl Acad Sci U S A ; 119(37): e2121385119, 2022 Sep 13.
Article in English | MEDLINE | ID: mdl-36067309

ABSTRACT

Interferon (IFN) regulatory factor 3 (IRF3) is a transcription factor activated by phosphorylation in the cytoplasm of a virus-infected cell; by translocating to the nucleus, it induces transcription of IFN-ß and other antiviral genes. We have previously reported IRF3 can also be activated, as a proapoptotic factor, by its linear polyubiquitination mediated by the RIG-I pathway. Both transcriptional and apoptotic functions of IRF3 contribute to its antiviral effect. Here, we report a nontranscriptional function of IRF3, namely, the repression of IRF3-mediated NF-κB activity (RIKA), which attenuated viral activation of NF-κB and the resultant inflammatory gene induction. In Irf3-/- mice, consequently, Sendai virus infection caused enhanced inflammation in the lungs. Mechanistically, RIKA was mediated by the direct binding of IRF3 to the p65 subunit of NF-κB in the cytoplasm, which prevented its nuclear import. A mutant IRF3 defective in both the transcriptional and the apoptotic activities was active in RIKA and inhibited virus replication. Our results demonstrated IRF3 deployed a three-pronged attack on virus replication and the accompanying inflammation.


Subject(s)
Immunity, Innate , Interferon Regulatory Factor-3 , NF-kappa B , Pneumonia, Viral , Active Transport, Cell Nucleus , Animals , Cell Nucleus/metabolism , Gene Expression , Interferon Regulatory Factor-3/genetics , Interferon Regulatory Factor-3/metabolism , Interferon-beta/genetics , Mice , NF-kappa B/metabolism , Pneumonia, Viral/genetics , Pneumonia, Viral/immunology , Sendai virus
3.
BMC Infect Dis ; 22(1): 343, 2022 Apr 06.
Article in English | MEDLINE | ID: mdl-35382755

ABSTRACT

BACKGROUND: Pneumonia is a common complication of influenza and closely related to mortality in influenza patients. The present study examines cytokines as predictors of the prognosis of influenza-associated pneumonia. METHODS: This study included 101 inpatients with influenza (64 pneumonia and 37 non-pneumonia patients). 48 cytokines were detected in the serum samples of the patients and the clinical characteristics were analyzed. The correlation between them was analyzed to identify predictive biomarkers for the prognosis of influenza-associated pneumonia. RESULTS: Seventeen patients had poor prognosis and developed pneumonia. Among patients with influenza-associated pneumonia, the levels of 8 cytokines were significantly higher in those who had a poor prognosis: interleukin-6 (IL-6), interferon-γ (IFN-γ), granulocyte colony-stimulating factor (G-CSF), monocyte colony-stimulating factor (M-CSF), monocyte chemoattractant protein-1 (MCP-1), monocyte chemoattractant protein-3, Interleukin-2 receptor subunit alpha and Hepatocyte growth factor. Correlation analysis showed that the IL-6, G-CSF, M-CSF, IFN-γ, and MCP-1 levels had positive correlations with the severity of pneumonia. IL-6 and G-CSF showed a strong and positive correlation with poor prognosis in influenza-associated pneumonia patients. The combined effect of the two cytokines resulted in the largest area (0.926) under the receiver-operating characteristic curve. CONCLUSION: The results indicate that the probability of poor prognosis in influenza patients with pneumonia is significantly increased. IL-6, G-CSF, M-CSF, IFN-γ, and MCP-1 levels had a positive correlation with the severity of pneumonia. Importantly, IL-6 and G-CSF were identified as significant predictors of the severity of influenza-associated pneumonia.


Subject(s)
Granulocyte Colony-Stimulating Factor , Influenza, Human , Interleukin-6 , Pneumonia, Viral , Cytokines/blood , Granulocyte Colony-Stimulating Factor/blood , Humans , Influenza, Human/complications , Influenza, Human/immunology , Interleukin-6/blood , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Prognosis
6.
J Immunol Res ; 2021: 2958394, 2021.
Article in English | MEDLINE | ID: mdl-34926703

ABSTRACT

Adenovirus (Ad) is a major causal agent of acute respiratory infections. However, they are a powerful delivery system for gene therapy and vaccines. Some Ad serotypes antagonize the immune system leading to meningitis, conjunctivitis, gastroenteritis, and/or acute hemorrhagic cystitis. Studies have shown that the release of small, membrane-derived extracellular vesicles (EVs) may offer a mechanism by which viruses can enter cells via receptor-independent entry and how they influence disease pathogenesis and/or host protection considering their existence in almost all bodily fluids. We proposed that Ad3 could alter EV biogenesis, composition, and trafficking and may stimulate various immune responses in vitro. In the present study, we evaluated the impact of in vitro infection with Ad3 vector on EV biogenesis and composition in the human adenocarcinoma lung epithelial cell line A549. Cells were infected in an exosome-free media at different multiplicity of infections (MOIs) and time points. The cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and fluorometric calcein-AM. EVs were isolated via ultracentrifugation. Isolated EV proteins were quantified and evaluated via nanoparticle tracking, transmission electron microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunoblotting assays. The cell viability significantly decreased with an increase in MOI and incubation time. A significant increase in particle mean sizes, concentrations, and total EV protein content was detected at higher MOIs when compared to uninfected cells (control group). A549 cell-derived EVs revealed the presence of TSG101, tetraspanins CD9 and CD63, and heat shock proteins 70 and 100 with significantly elevated levels of Rab5, 7, and 35 at higher MOIs (300, 750, and 1500) when compared to the controls. Our findings suggested Ad3 could modulate EV biogenesis, composition, and trafficking which could impact infection pathogenesis and disease progression. This study might suggest EVs could be diagnostic and therapeutic advancement to Ad infections and other related viral infections. However, further investigation is warranted to explore the underlying mechanism(s).


Subject(s)
Adenovirus Infections, Human/immunology , Adenoviruses, Human/immunology , Extracellular Vesicles/immunology , Lung/pathology , Pneumonia, Viral/immunology , A549 Cells , Adenovirus Infections, Human/pathology , Adenovirus Infections, Human/virology , Adenoviruses, Human/genetics , Cell Survival/immunology , Extracellular Vesicles/metabolism , Humans , Lung/cytology , Lung/immunology , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Serogroup
7.
Viruses ; 13(12)2021 11 28.
Article in English | MEDLINE | ID: mdl-34960654

ABSTRACT

The host immunity of patients with adenovirus pneumonia in different severity of illness is unclear. This study compared the routine laboratory tests and the host immunity of human adenovirus (HAdV) patients with different severity of illness. A co-cultured cell model in vitro was established to verify the T cell response in vitro. Among 140 patients with confirmed HAdV of varying severity, the number of lymphocytes in the severe patients was significantly reduced to 1.91 × 109/L compared with the healthy control (3.92 × 109/L) and the mild patients (4.27 × 109/L). The levels of IL-6, IL-10, and IFN-γ in patients with adenovirus pneumonia were significantly elevated with the severity of the disease. Compared with the healthy control (20.82%) and the stable patients (33.96%), the percentage of CD8+ T cells that produced IFN-γ increased to 56.27% in the progressing patients. Adenovirus infection increased the percentage of CD8+ T and CD4+ T cells that produce IFN-γ in the co-culture system. The hyperfunction of IFN-γ+ CD8+ T cells might be related to the severity of adenovirus infection. The in vitro co-culture cell model could also provide a usable cellular model for subsequent experiments.


Subject(s)
Adenovirus Infections, Human/immunology , Adenoviruses, Human/physiology , CD8-Positive T-Lymphocytes/microbiology , Interferon-gamma/immunology , Pneumonia, Viral/immunology , Adenovirus Infections, Human/genetics , Adenovirus Infections, Human/pathology , Adenovirus Infections, Human/virology , Adenoviruses, Human/genetics , Child , Child, Preschool , Female , Humans , Infant , Interferon-gamma/genetics , Interleukin-10/genetics , Interleukin-10/immunology , Interleukin-6/genetics , Interleukin-6/immunology , Lymphocyte Count , Male , Patient Acuity , Pneumonia, Viral/genetics , Pneumonia, Viral/pathology , Pneumonia, Viral/virology
8.
mBio ; 12(6): e0274921, 2021 12 21.
Article in English | MEDLINE | ID: mdl-34749524

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a historic pandemic of respiratory disease (coronavirus disease 2019 [COVID-19]), and current evidence suggests that severe disease is associated with dysregulated immunity within the respiratory tract. However, the innate immune mechanisms that mediate protection during COVID-19 are not well defined. Here, we characterize a mouse model of SARS-CoV-2 infection and find that early CCR2 signaling restricts the viral burden in the lung. We find that a recently developed mouse-adapted SARS-CoV-2 (MA-SARS-CoV-2) strain as well as the emerging B.1.351 variant trigger an inflammatory response in the lung characterized by the expression of proinflammatory cytokines and interferon-stimulated genes. Using intravital antibody labeling, we demonstrate that MA-SARS-CoV-2 infection leads to increases in circulating monocytes and an influx of CD45+ cells into the lung parenchyma that is dominated by monocyte-derived cells. Single-cell RNA sequencing (scRNA-Seq) analysis of lung homogenates identified a hyperinflammatory monocyte profile. We utilize this model to demonstrate that mechanistically, CCR2 signaling promotes the infiltration of classical monocytes into the lung and the expansion of monocyte-derived cells. Parenchymal monocyte-derived cells appear to play a protective role against MA-SARS-CoV-2, as mice lacking CCR2 showed higher viral loads in the lungs, increased lung viral dissemination, and elevated inflammatory cytokine responses. These studies have identified a potential CCR2-monocyte axis that is critical for promoting viral control and restricting inflammation within the respiratory tract during SARS-CoV-2 infection. IMPORTANCE SARS-CoV-2 has caused a historic pandemic of respiratory disease (COVID-19), and current evidence suggests that severe disease is associated with dysregulated immunity within the respiratory tract. However, the innate immune mechanisms that mediate protection during COVID-19 are not well defined. Here, we characterize a mouse model of SARS-CoV-2 infection and find that early CCR2-dependent infiltration of monocytes restricts the viral burden in the lung. We find that SARS-CoV-2 triggers an inflammatory response in the lung characterized by the expression of proinflammatory cytokines and interferon-stimulated genes. Using RNA sequencing and flow cytometry approaches, we demonstrate that SARS-CoV-2 infection leads to increases in circulating monocytes and an influx of CD45+ cells into the lung parenchyma that is dominated by monocyte-derived cells. Mechanistically, CCR2 signaling promoted the infiltration of classical monocytes into the lung and the expansion of monocyte-derived cells. Parenchymal monocyte-derived cells appear to play a protective role against MA-SARS-CoV-2, as mice lacking CCR2 showed higher viral loads in the lungs, increased lung viral dissemination, and elevated inflammatory cytokine responses. These studies have identified that the CCR2 pathway is critical for promoting viral control and restricting inflammation within the respiratory tract during SARS-CoV-2 infection.


Subject(s)
Lung/immunology , Pneumonia, Viral/prevention & control , Receptors, CCR2/immunology , SARS-CoV-2/immunology , Signal Transduction/immunology , Animals , COVID-19 , Cytokines/immunology , Disease Models, Animal , Female , Immunity, Innate , Inflammation , Lung/cytology , Lung/virology , Mice , Mice, Inbred C57BL , Monocytes/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Receptors, CCR2/genetics , Receptors, CCR2/metabolism , SARS-CoV-2/genetics , Viral Load , Virus Replication/immunology
9.
Expert Rev Gastroenterol Hepatol ; 15(11): 1281-1294, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34654347

ABSTRACT

INTRODUCTION: Human gut microbiota plays a crucial role in providing protective responses against pathogens, particularly by regulating immune system homeostasis. There is a reciprocal interaction between the gut and lung microbiota, called the gut-lung axis (GLA). Any alteration in the gut microbiota or their metabolites can cause immune dysregulation, which can impair the antiviral activity of the immune system against respiratory viruses such as severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2. AREAS COVERED: This narrative review mainly outlines emerging data on the mechanisms underlying the interactions between the immune system and intestinal microbial dysbiosis, which is caused by an imbalance in the levels of essential metabolites. The authors will also discuss the role of probiotics in restoring the balance of the gut microbiota and modulation of cytokine storm. EXPERT OPINION: Microbiota-derived signals regulate the immune system and protect different tissues during severe viral respiratory infections. The GLA's equilibration could help manage the mortality and morbidity rates associated with SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , Dysbiosis/immunology , Gastrointestinal Microbiome/immunology , Immune System/immunology , Pneumonia, Viral/immunology , Humans , SARS-CoV-2
10.
Bioengineered ; 12(2): 10335-10344, 2021 12.
Article in English | MEDLINE | ID: mdl-34699306

ABSTRACT

It focused on the antiviral immune regulation of biofilm-localized protein kinase Dbf2p-related kinase 1 (NDR1) in viral pneumonia. Mouse alveolar monocyte RAW264.7 was used as blank control, and viral pneumonia cell model was prepared by infecting cells with respiratory syncytial virus (RSV). NDR1 overexpression vector and siRNA interference sequences were synthesized, and overexpression/silence NDR1 cell model was fabricated. About 50 ng/mL interleukin 17 (IL-17) was given to stimulate. Enzyme-linked immunosorbent assay (ELISA), quantitative reverse transcription PCR (RT-qRCR), and Western blot were performed to detect cytokines and chemokines, mRNA of inflammatory factors, and signal molecule protein expression. Notably, RSV infection increased RSV-F mRNA in RAW264.7 cells and reduced NDR1 mRNA and protein. Secretion levels of IL-6, interferon ß (IFN-ß), chemokine (C-X-C motif) ligand 2 (CXCL2), and chemokine (C-C motif) ligand 2 (CCL20) increased in the model group versus blank control (P< 0.05). IL-6, IFN-ß, tumor necrosis factor α (TNF-α), and toll-like receptor 3 (TLR3) mRNA were up-regulated (P < 0.05). Extracellular signal-regulated kinase (ERK1/2), p38 protein phosphorylation, human recombinant 1 (TBK1), and nuclear factor kappa-B (NF-κB) protein levels increased (P < 0.05). After overexpression of NDR1, the secretion levels of cytokines and chemokines, inflammatory factors mRNA, and signal molecule protein increased significantly. After NDR1 was silenced, cytokines and chemokines, inflammatory factors mRNA, and signal molecule protein were not significantly different versus blank control group (P > 0.05). In short, NDR1 regulated innate immune response to viral pneumonia induced by IL-17, which can be used as a new target for the treatment of IL-17-induced inflammatory response and autoimmune diseases.


Subject(s)
Biofilms/growth & development , Immunity, Innate , Interleukin-17/metabolism , Pneumonia, Viral/enzymology , Pneumonia, Viral/immunology , Animals , Cell Proliferation , Chemokines/metabolism , Inflammation/pathology , Mice , RAW 264.7 Cells , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Viruses/physiology , Signal Transduction
11.
Eur J Immunol ; 51(12): 3194-3201, 2021 12.
Article in English | MEDLINE | ID: mdl-34564853

ABSTRACT

Accelerate lung repair in SARS-CoV-2 pneumonia is essential for pandemic handling. Innate lymphoid cells (ILCs) are likely players, given their role in mucosal protection and tissue homeostasis. We studied ILC subpopulations at two time points in a cohort of patients admitted in the hospital due to SARS-CoV-2 infection. COVID-19 patients with moderate/severe respiratory failure featured profound depletion of circulating ILCs at hospital admission, in agreement with overall lymphocyte depletion. However, ILCs recovered in direct correlation with lung function improvement as measured by oxygenation index and in negative association with inflammatory and lung/endothelial damage markers like RAGE. While both ILC1 and ILC2 expanded, ILC2 showed the most striking phenotype changes, with CCR10 upregulation in strong correlation with these parameters. Overall, CCR10+ ILC2 emerge as relevant contributors to SARS-CoV-2 pneumonia recovery.


Subject(s)
Biomarkers/metabolism , COVID-19/immunology , Lung/pathology , Lymphocytes/immunology , Pneumonia, Viral/immunology , Receptors, CCR10/metabolism , SARS-CoV-2/physiology , Adult , Aged , Antigens, Neoplasm/metabolism , Cell Proliferation , Cytokines/metabolism , Female , Humans , Immunity, Innate , Male , Middle Aged , Mitogen-Activated Protein Kinases/metabolism , Recovery of Function , Th2 Cells/immunology , Up-Regulation
12.
Front Immunol ; 12: 704427, 2021.
Article in English | MEDLINE | ID: mdl-34489955

ABSTRACT

Viral pneumonias are a major cause of morbidity and mortality, owing in part to dysregulated excessive lung inflammation, and therapies to modulate host responses to viral lung injury are urgently needed. Protectin conjugates in tissue regeneration 1 (PCTR1) and protectin D1 (PD1) are specialized pro-resolving mediators (SPMs) whose roles in viral pneumonia are of interest. In a mouse model of Respiratory Syncytial Virus (RSV) pneumonia, intranasal PCTR1 and PD1 each decreased RSV genomic viral load in lung tissue when given after RSV infection. Concurrent with enhanced viral clearance, PCTR1 administration post-infection, decreased eosinophils, neutrophils, and NK cells, including NKG2D+ activated NK cells, in the lung. Intranasal PD1 administration post-infection decreased lung eosinophils and Il-13 expression. PCTR1 increased lung expression of cathelicidin anti-microbial peptide and decreased interferon-gamma production by lung CD4+ T cells. PCTR1 and PD1 each increased interferon-lambda expression in human bronchial epithelial cells in vitro and attenuated RSV-induced suppression of interferon-lambda in mouse lung in vivo. Liquid chromatography coupled with tandem mass spectrometry of RSV-infected and untreated mouse lungs demonstrated endogenous PCTR1 and PD1 that decreased early in the time course while cysteinyl-leukotrienes (cys-LTs) increased during early infection. As RSV infection resolved, PCTR1 and PD1 increased and cys-LTs decreased to pre-infection levels. Together, these results indicate that PCTR1 and PD1 are each regulated during RSV pneumonia, with overlapping and distinct mechanisms for PCTR1 and PD1 during the resolution of viral infection and its associated inflammation.


Subject(s)
Docosahexaenoic Acids/pharmacology , Lung/immunology , Pneumonia, Viral , Respiratory Syncytial Virus Infections , Respiratory Syncytial Viruses/immunology , Administration, Intranasal , Animals , Inflammation/immunology , Inflammation/prevention & control , Lung/virology , Male , Mice , Pneumonia, Viral/immunology , Pneumonia, Viral/prevention & control , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus Infections/prevention & control , Viral Load/drug effects
13.
Front Immunol ; 12: 727941, 2021.
Article in English | MEDLINE | ID: mdl-34504501

ABSTRACT

Influenza A virus infection is usually associated with acute lung injury, which is typically characterized by tracheal mucosal barrier damage and an interleukin 17A (IL-17A)-mediated inflammatory response in lung tissues. Although targeting IL-17A has been proven to be beneficial for attenuating inflammation around lung cells, it still has a limited effect on pulmonary tissue recovery after influenza A virus infection. In this research, interleukin 22 (IL-22), a cytokine involved in the repair of the pulmonary mucosal barrier, was fused to the C-terminus of the anti-IL-17A antibody vunakizumab to endow the antibody with a tissue recovery function. The vunakizumab-IL22 (vmab-IL-22) fusion protein exhibits favorable stability and retains the biological activities of both the anti-IL-17A antibody and IL-22 in vitro. Mice infected with lethal H1N1 influenza A virus and treated with vmab-mIL22 showed attenuation of lung index scores and edema when compared to those of mice treated with saline or vmab or mIL22 alone. Our results also illustrate that vmab-mIL22 triggers the upregulation of MUC2 and ZO1, as well as the modulation of cytokines such as IL-1ß, HMGB1 and IL-10, indicating the recovery of pulmonary goblet cells and the suppression of excessive inflammation in mice after influenza A virus infection. Moreover, transcriptome profiling analysis suggest the downregulation of fibrosis-related genes and signaling pathways, including genes related to focal adhesion, the inflammatory response pathway, the TGF-ß signaling pathway and lung fibrosis upon vmab-mIL22 treatment, which indicates that the probable mechanism of vmab-mIL22 in ameliorating H1N1 influenza A-induced lung injury. Our results reveal that the bifunctional fusion protein vmab-mIL22 can trigger potent therapeutic effects in H1N1-infected mice by enhancing lung tissue recovery and inhibiting pulmonary inflammation, which highlights a potential approach for treating influenza A virus infection by targeting IL-17A and IL-22 simultaneously.


Subject(s)
Acute Lung Injury/drug therapy , Antibodies, Monoclonal/immunology , Antiviral Agents/therapeutic use , Influenza A Virus, H1N1 Subtype , Interleukin-17/immunology , Interleukins/immunology , Orthomyxoviridae Infections/drug therapy , Pneumonia, Viral/drug therapy , Recombinant Fusion Proteins/therapeutic use , Acute Lung Injury/genetics , Acute Lung Injury/immunology , Acute Lung Injury/pathology , Animals , Antibodies, Monoclonal/genetics , Antiviral Agents/pharmacology , CHO Cells , Cricetulus , HT29 Cells , Hep G2 Cells , Humans , Interleukins/genetics , Lung/drug effects , Lung/immunology , Lung/pathology , Male , Mice, Inbred BALB C , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/pathology , Pneumonia, Viral/genetics , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , Recombinant Fusion Proteins/pharmacology , Transcriptome/drug effects
14.
Cell Rep ; 37(1): 109798, 2021 10 05.
Article in English | MEDLINE | ID: mdl-34587481

ABSTRACT

Despite the worldwide effect of the coronavirus disease 2019 (COVID-19) pandemic, the underlying mechanisms of fatal viral pneumonia remain elusive. Here, we show that critical COVID-19 is associated with enhanced eosinophil-mediated inflammation when compared to non-critical cases. In addition, we confirm increased T helper (Th)2-biased adaptive immune responses, accompanying overt complement activation, in the critical group. Moreover, enhanced antibody responses and complement activation are associated with disease pathogenesis as evidenced by formation of immune complexes and membrane attack complexes in airways and vasculature of lung biopsies from six fatal cases, as well as by enhanced hallmark gene set signatures of Fcγ receptor (FcγR) signaling and complement activation in myeloid cells of respiratory specimens from critical COVID-19 patients. These results suggest that SARS-CoV-2 infection may drive specific innate immune responses, including eosinophil-mediated inflammation, and subsequent pulmonary pathogenesis via enhanced Th2-biased immune responses, which might be crucial drivers of critical disease in COVID-19 patients.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Complement System Proteins/immunology , Eosinophils/immunology , Inflammation/immunology , Pneumonia, Viral/immunology , SARS-CoV-2/immunology , Adaptive Immunity , Adult , Aged , Aged, 80 and over , Antigen-Antibody Complex/metabolism , COVID-19/metabolism , COVID-19/virology , Complement Activation , Complement Membrane Attack Complex/metabolism , Eosinophils/virology , Female , Humans , Inflammation/metabolism , Inflammation/virology , Lung Injury/immunology , Lung Injury/pathology , Lung Injury/virology , Male , Middle Aged , Pneumonia, Viral/metabolism , Receptors, IgG/immunology , Receptors, IgG/metabolism , Severity of Illness Index , Signal Transduction , Th2 Cells/immunology , Viral Load , Young Adult
15.
World J Pediatr ; 17(4): 375-384, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34341947

ABSTRACT

BACKGROUND: Severe cases of coronavirus disease 2019 (COVID-19) among pediatric patients are more common in children less than 1 year of age. Our aim is to address the underlying role of immunity and inflammation conditions among different age groups of pediatric patients. METHODS: We recruited pediatric patients confirmed of moderate COVID-19 symptoms, admitted to Wuhan Children's Hospital from January 28th to April 1st in 2020. Patients were divided into four age groups (≤ 1, 1-6, 7-10, and 11-15 years). Demographic information, clinical characteristics, laboratory results of lymphocyte subsets test, immune and inflammation related markers were all evaluated. RESULTS: Analysis included 217/241 (90.0%) of patients with moderate clinical stage disease. Average recovery time of children more than 6 years old was significantly shorter than of children younger than 6 years (P = 0.001). Reduced neutrophils and increased lymphocytes were significantly most observed among patients under 1 year old (P < 0.01). CD19+ B cells were the only significantly elevated immune cells, especially among patients under 1 year old (cell proportion: n = 12, 30.0%, P < 0.001; cell count: n = 13, 32.5%, P < 0.001). While, low levels of immune related makers, such as immunoglobulin (Ig) G (P < 0.001), IgA (P < 0.001), IgM (P < 0.001) and serum complement C3c (P < 0.001), were also mostly found among patients under 1 year old, together with elevated levels of inflammation related markers, such as tumor necrosis factor γ (P = 0.007), interleukin (IL)-10 (P = 0.011), IL-6 (P = 0.008), lactate dehydrogenase (P < 0.001), and procalcitonin (P = 0.007). CONCLUSION: The higher rate of severe cases and long course of COVID-19 among children under 1 year old may be due to the lower production of antibodies and serum complements of in this age group.


Subject(s)
COVID-19/immunology , Pneumonia, Viral/immunology , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/immunology , Adolescent , Biomarkers/blood , COVID-19/epidemiology , Child , Child, Preschool , China/epidemiology , Cytokines/immunology , Female , Hospitals, Pediatric , Humans , Infant , Lymphocyte Subsets , Male , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Severity of Illness Index , Systemic Inflammatory Response Syndrome/epidemiology
16.
Biomed Res Int ; 2021: 9987931, 2021.
Article in English | MEDLINE | ID: mdl-34423043

ABSTRACT

OBJECTIVE: Respiratory failure is the leading cause of mortality in COVID-19 patients, characterized by a generalized disbalance of inflammation. The aim of this study was to investigate the relationship between immune-inflammatory index and mortality in PSI IV-V patients with COVID-19. METHODS: We retrospectively reviewed the medical records of COVID-19 patients from Feb. to Apr. 2020 in the Zhongfa Xincheng Branch of Tongji Hospital, Wuhan, China. Patients who presented high severity of COVID-19-related pneumonia were enrolled for further analysis according to the Pneumonia Severity Index (PSI) tool. RESULTS: A total of 101 patients diagnosed with COVID-19 were identified at initial research. The survival analysis revealed that mortality of the PSI IV-V cohort was significantly higher than the PSI I-III group (p = 0.0003). The overall mortality in PSI IV-V patients was 32.1% (9/28). The fatal cases of the PSI IV-V group had a higher level of procalcitonin (p = 0.022) and neutrophil-to-lymphocyte ratio (p = 0.033) compared with the survivors. Procalcitonin was the most sensitive predictor of mortality for the severe COVID-19 population with area under receiver operating characteristic curve of 0.78, higher than the neutrophil-to-lymphocyte ratio (0.75) and total lymphocyte (0.68) and neutrophil (0.67) counts. CONCLUSION: Procalcitonin and neutrophil-to-lymphocyte ratio may potentially be effective predictors for mortality in PSI IV-V patients with COVID-19. Increased procalcitonin and neutrophil-to-lymphocyte ratio were associated with greater risk of mortality.


Subject(s)
COVID-19/immunology , COVID-19/physiopathology , Pandemics , SARS-CoV-2 , Aged , Aged, 80 and over , Biomarkers/blood , COVID-19/mortality , China/epidemiology , Cohort Studies , Female , Humans , Inflammation/immunology , Inflammation/physiopathology , Lymphocytes/immunology , Male , Middle Aged , Neutrophils/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/mortality , Pneumonia, Viral/physiopathology , Procalcitonin/blood , Prognosis , Retrospective Studies , Risk Factors , Severity of Illness Index , Survival Analysis
17.
FASEB J ; 35(9): e21801, 2021 09.
Article in English | MEDLINE | ID: mdl-34365657

ABSTRACT

The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a crucial role in mediating viral entry into host cells. However, whether it contributes to pulmonary hyperinflammation in patients with coronavirus disease 2019 is not well known. In this study, we developed a spike protein-pseudotyped (Spp) lentivirus with the proper tropism of the SARS-CoV-2 spike protein on the surface and determined the distribution of the Spp lentivirus in wild-type C57BL/6J male mice that received an intravenous injection of the virus. Lentiviruses with vesicular stomatitis virus glycoprotein (VSV-G) or with a deletion of the receptor-binding domain (RBD) in the spike protein [Spp (∆RBD)] were used as controls. Two hours postinfection (hpi), there were 27-75 times more viral burden from Spp lentivirus in the lungs than in other organs; there were also about 3-5 times more viral burden from Spp lentivirus than from VSV-G lentivirus in the lungs, liver, kidney, and spleen. Deletion of RBD diminished viral loads in the lungs but not in the heart. Acute pneumonia was observed in animals 24 hpi. Spp lentivirus was mainly found in SPC+ and LDLR+ pneumocytes and macrophages in the lungs. IL6, IL10, CD80, and PPAR-γ were quickly upregulated in response to infection in the lungs as well as in macrophage-like RAW264.7 cells. Furthermore, forced expression of the spike protein in RAW264.7 cells significantly increased the mRNA levels of the same panel of inflammatory factors. Our results demonstrated that the spike protein of SARS-CoV-2 confers the main point of viral entry into the lungs and can induce cellular pathology. Our data also indicate that an alternative ACE2-independent viral entry pathway may be recruited in the heart and aorta.


Subject(s)
Macrophages/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , Spike Glycoprotein, Coronavirus/immunology , Acute Disease , Alveolar Epithelial Cells/virology , Animals , B7-1 Antigen , Cell Line , Inflammation Mediators , Interleukin-10 , Interleukin-6 , Lentivirus/genetics , Lentivirus/isolation & purification , Lentivirus/metabolism , Lung/immunology , Lung/pathology , Lung/virology , Macrophages/virology , Male , Membrane Glycoproteins , Mice , Mice, Inbred C57BL , PPAR gamma , RAW 264.7 Cells , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Viral Envelope Proteins
18.
J Immunol ; 207(5): 1229-1238, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34348975

ABSTRACT

Infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or seasonal influenza may lead to respiratory failure requiring intubation and mechanical ventilation. The pathophysiology of this respiratory failure is attributed to local immune dysregulation, but how the immune response to viral infection in the lower airways of the human lung differs between individuals with respiratory failure and those without is not well understood. We used quantitative multiparameter flow cytometry and multiplex cytokine assays to evaluate matched blood and bronchoalveolar lavage (BAL) samples from control human subjects, subjects with symptomatic seasonal influenza who did not have respiratory failure, and subjects with severe seasonal influenza or SARS-CoV-2 infection with respiratory failure. We find that severe cases are associated with an influx of nonclassical monocytes, activated T cells, and plasmablast B cells into the lower airways. Cytokine concentrations were not elevated in the lower airways of moderate influenza patients compared with controls; however, 28 of 35 measured cytokines were significantly elevated in severe influenza, severe SARS-CoV-2 infection, or both. We noted the largest elevations in IL-6, IP-10, MCP-1, and IL-8. IL-1 family cytokines and RANTES were higher in severe influenza infection than severe SARS-CoV-2 infection. Interestingly, only the concentration of IP-10-correlated between blood and BAL during severe infection. Our results demonstrate inflammatory immune dysregulation in the lower airways during severe viral pneumonia that is distinct from lower airway responses seen in human patients with symptomatic, but not severe, illness and suggest that measurement of blood IP-10 concentration may predict this unique dysregulation.


Subject(s)
COVID-19/immunology , Influenza A virus/physiology , Pneumonia, Viral/immunology , Respiratory System/immunology , SARS-CoV-2/physiology , Adult , Aged , Blood Proteins/metabolism , Bronchoalveolar Lavage Fluid/immunology , COVID-19/diagnosis , Chemokine CXCL10/metabolism , Cohort Studies , Female , Humans , Inflammation Mediators/metabolism , Influenza, Human/immunology , Male , Middle Aged , Prospective Studies , Respiratory Insufficiency , Severity of Illness Index
19.
J Clin Invest ; 131(14)2021 07 15.
Article in English | MEDLINE | ID: mdl-34263736

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic is among the most important public health crises of our generation. Despite the promise of prevention offered by effective vaccines, patients with severe COVID-19 will continue to populate hospitals and intensive care units for the foreseeable future. The most common clinical presentation of severe COVID-19 is hypoxemia and respiratory failure, typical of the acute respiratory distress syndrome (ARDS). Whether the clinical features and pathobiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia differ from those of pneumonia secondary to other pathogens is unclear. This uncertainty has created variability in the application of historically proven therapies for ARDS to patients with COVID-19. We review the available literature and find many similarities between patients with ARDS from pneumonia attributable to SARS-CoV-2 versus other respiratory pathogens. A notable exception is the long duration of illness among patients with COVID-19, which could result from its unique pathobiology. Available data support the use of care pathways and therapies proven effective for patients with ARDS, while pointing to unique features that might be therapeutically targeted for patients with severe SARS-CoV-2 pneumonia.


Subject(s)
COVID-19/etiology , Pneumonia, Viral/etiology , Respiratory Distress Syndrome/etiology , SARS-CoV-2 , Angiotensin-Converting Enzyme 2/physiology , Autopsy , COVID-19/epidemiology , COVID-19/pathology , Cytokines/biosynthesis , Humans , Lung/immunology , Lung/pathology , Lung/virology , Macrophages, Alveolar/immunology , Macrophages, Alveolar/virology , Models, Biological , Pandemics , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , Receptors, Virus/physiology , Respiratory Distress Syndrome/immunology , Respiratory Distress Syndrome/pathology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Severity of Illness Index
20.
Toxicol Appl Pharmacol ; 426: 115645, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34271066

ABSTRACT

Elevated ambient temperatures and extreme weather events have increased the incidence of wildfires world-wide resulting in increased wood smoke particle (WSP). Epidemiologic data suggests that WSP exposure associates with exacerbations of respiratory diseases, and with increased respiratory viral infections. To assess the impact of WSP exposure on host response to viral pneumonia, we performed WSP exposures in rodents followed by infection with mouse adapted influenza (HINI-PR8). C57BL/6 male mice aged 6-8 weeks were challenged with WSP or PBS by oropharyngeal aspiration in acute (single dose) or sub-acute exposures (day 1, 3, 5, 7 and 10). Additional groups underwent sub-acute exposure followed by infection by influenza or heat-inactivated (HI) virus. Following exposures/infection, bronchoalveolar lavage (BAL) was performed to assess for total cell counts/differentials, total protein, protein carbonyls and hyaluronan. Lung tissue was assessed for viral counts by real time PCR. When compared to PBS, acute WSP exposure associated with an increase in airspace macrophages. Alternatively, sub-acute exposure resulted in a dose dependent increase in airspace neutrophils. Sub-acute WSP exposure followed by influenza infection was associated with improved respiratory viral outcomes including reduced weight loss and increased blood oxygen saturation, and decreased protein carbonyls and viral titers. Flow cytometry demonstrated dynamic changes in pulmonary macrophage and T cell subsets based on challenge with WSP and influenza. This data suggests that sub-acute WSP exposure can improve host response to acute influenza infection.


Subject(s)
Influenza A Virus, H1N1 Subtype , Orthomyxoviridae Infections , Pneumonia, Viral , Smoke , Wildfires , Administration, Inhalation , Animals , Influenza A Virus, H1N1 Subtype/physiology , Lung/immunology , Lung/metabolism , Lung/virology , Macrophages/immunology , Male , Mice , Mice, Inbred C57BL , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/metabolism , Orthomyxoviridae Infections/virology , Pneumonia, Viral/immunology , Pneumonia, Viral/metabolism , Pneumonia, Viral/virology , Severity of Illness Index , Transcriptome , Virus Replication , Wood
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