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1.
Biochemistry (Mosc) ; 86(7): 800-817, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1594970

ABSTRACT

COVID-19, a new human respiratory disease that has killed nearly 3 million people in a year since the start of the pandemic, is a global public health challenge. Its infectious agent, SARS-CoV-2, differs from other coronaviruses in a number of structural features that make this virus more pathogenic and transmissible. In this review, we discuss some important characteristics of the main SARS-CoV-2 surface antigen, the spike (S) protein, such as (i) ability of the receptor-binding domain (RBD) to switch between the "standing-up" position (open pre-fusion conformation) for receptor binding and the "lying-down" position (closed pre-fusion conformation) for immune system evasion; (ii) advantage of a high binding affinity of the RBD open conformation to the human angiotensin-converting enzyme 2 (ACE2) receptor for efficient cell entry; and (iii) S protein preliminary activation by the intracellular furin-like proteases for facilitation of the virus spreading across different cell types. We describe interactions between the S protein and cellular receptors, co-receptors, and antagonists, as well as a hypothetical mechanism of the homotrimeric spike structure destabilization that triggers the fusion of the viral envelope with the cell membrane at physiological pH and mediates the viral nucleocapsid entry into the cytoplasm. The transition of the S protein pre-fusion conformation to the post-fusion one on the surface of virions after their treatment with some reagents, such as ß-propiolactone, is essential, especially in relation to the vaccine production. We also compare the COVID-19 pathogenesis with that of severe outbreaks of "avian" influenza caused by the A/H5 and A/H7 highly pathogenic viruses and discuss the structural similarities between the SARS-CoV-2 S protein and hemagglutinins of those highly pathogenic strains. Finally, we touch on the prospective and currently used COVID-19 antiviral and anti-pathogenetic therapeutics, as well as recently approved conventional and innovative COVID-19 vaccines and their molecular and immunological features.


Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Pandemics , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/epidemiology , COVID-19/genetics , COVID-19/metabolism , Humans , Influenza A virus/chemistry , Influenza A virus/genetics , Influenza A virus/metabolism , Influenza, Human/epidemiology , Influenza, Human/genetics , Influenza, Human/metabolism , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
2.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Article in English | MEDLINE | ID: covidwho-1595265

ABSTRACT

Infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) provokes a potentially fatal pneumonia with multiorgan failure, and high systemic inflammation. To gain mechanistic insight and ferret out the root of this immune dysregulation, we modeled, by in vitro coculture, the interactions between infected epithelial cells and immunocytes. A strong response was induced in monocytes and B cells, with a SARS-CoV-2-specific inflammatory gene cluster distinct from that seen in influenza A or Ebola virus-infected cocultures, and which reproduced deviations reported in blood or lung myeloid cells from COVID-19 patients. A substantial fraction of the effect could be reproduced after individual transfection of several SARS-CoV-2 proteins (Spike and some nonstructural proteins), mediated by soluble factors, but not via transcriptional induction. This response was greatly muted in monocytes from healthy children, perhaps a clue to the age dependency of COVID-19. These results suggest that the inflammatory malfunction in COVID-19 is rooted in the earliest perturbations that SARS-CoV-2 induces in epithelia.


Subject(s)
COVID-19/immunology , Epithelial Cells/immunology , Monocytes/immunology , SARS-CoV-2/pathogenicity , Adult , B-Lymphocytes/immunology , COVID-19/pathology , Child , Coculture Techniques , Ebolavirus/pathogenicity , Epithelial Cells/virology , Gene Expression Profiling , Humans , Inflammation , Influenza A virus/pathogenicity , Lung/immunology , Myeloid Cells/immunology , Species Specificity , Viral Proteins/immunology
3.
Aging (Albany NY) ; 13(23): 24931-24942, 2021 12 12.
Article in English | MEDLINE | ID: covidwho-1573020

ABSTRACT

Since the Coronavirus 19 (COVID-19) pandemic, several SARS-CoV-2 variants of concern (SARS-CoV-2 VOC) have been reported. The B.1.1.7 variant has been associated with increased mortality and transmission risk. Furthermore, cluster and possible co-infection cases could occur in the next influenza season or COVID-19 pandemic wave, warranting efficient diagnosis and treatment decision making. Here, we aimed to detect SARS-CoV-2 and other common respiratory viruses using multiplex RT-PCR developed on the LabTurbo AIO 48 open system. We performed a multicenter study to evaluate the performance and analytical sensitivity of the LabTurbo AIO 48 system for SARS-CoV-2, influenza A/B, and respiratory syncytial virus (RSV) using 652 nasopharyngeal swab clinical samples from patients. The LabTurbo AIO 48 system demonstrated a sensitivity of 9.4 copies/per PCR for N2 of SARS-CoV-2; 24 copies/per PCR for M of influenza A and B; and 24 copies/per PCR for N of RSV. The assay presented consistent performance in the multicenter study. The multiplex RT-PCR applied on the LabTurbo AIO 48 open platform provided highly sensitive, robust, and accurate results and enabled high-throughput detection of B.1.1.7, influenza A/B, and RSV with short turnaround times. Therefore, this automated molecular diagnostic assay could enable streamlined testing if COVID-19 becomes a seasonal disease.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Influenza, Human/diagnosis , Multiplex Polymerase Chain Reaction/methods , Respiratory Syncytial Virus Infections/diagnosis , Adult , Aged , COVID-19/virology , Female , Humans , Influenza A virus/genetics , Influenza A virus/isolation & purification , Influenza, Human/virology , Influenzavirus B/genetics , Influenzavirus B/isolation & purification , Male , Middle Aged , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Viruses/genetics , Respiratory Syncytial Viruses/isolation & purification , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Sensitivity and Specificity , Young Adult
4.
J Korean Med Sci ; 36(48): e328, 2021 Dec 13.
Article in English | MEDLINE | ID: covidwho-1572278

ABSTRACT

BACKGROUND: In the coronavirus disease 2019 (COVID-19) pandemic era, the simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus (Flu), and respiratory syncytial virus (RSV) is important in the rapid differential diagnosis in patients with respiratory symptoms. Three multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assays have been recently developed commercially in Korea: PowerChek™ SARS-CoV-2, Influenza A&B Multiplex Real-time PCR Kit (PowerChek; KogeneBiotech); STANDARD™ M Flu/SARS-CoV-2 Real-time Detection Kit (STANDARD M; SD BioSensor); and Allplex™ SARS-CoV-2/FluA/FluB/RSV Assay (Allplex; Seegene). We evaluated the analytical and clinical performances of these kits. METHODS: A limit of detection tests were performed and cross-reactivity analysis was executed using clinical respiratory samples. Ninety-seven SARS-CoV-2-positive, 201 SARS-CoV-2-negative, 71 influenza A-positive, 50 influenza B-positive, 78 RSV-positive, and 207 other respiratory virus-positive nasopharyngeal swabs were tested using the three assays. The AdvanSure™ respiratory viruses rRT-PCR assay (AdvanSure; LG Life Sciences) was used as a comparator assay for RSV. RESULTS: Except in influenza B, in SARS-CoV-2 and influenza A, there were no significant differences in detecting specific genes of the viruses among the three assays. All three kits did not cross-react with common respiratory viruses. All three kits had greater than 92% positive percent agreement and negative percent agreement and ≥ 0.95 kappa value in the detection of SARS-CoV-2 and flu A/B. Allplex detected RSV more sensitively than AdvanSure. CONCLUSION: The overall performance of three multiplex rRT-PCR assays for the concurrent detection of SARS-CoV-2, influenza A/B, and RSV was comparable. These kits will promote prompt differential diagnosis of COVID-19, influenza, and RSV infection in the COVID-19 pandemic era.


Subject(s)
COVID-19/diagnosis , Influenza, Human/diagnosis , Multiplex Polymerase Chain Reaction/methods , Nasopharynx/virology , RNA, Viral/analysis , Respiratory Syncytial Virus Infections/diagnosis , COVID-19/virology , Cross Reactions , Humans , Influenza A virus/genetics , Influenza A virus/isolation & purification , Influenza B virus/genetics , Influenza B virus/isolation & purification , Influenza, Human/virology , Limit of Detection , Nucleocapsid Proteins/genetics , Polyproteins/genetics , RNA, Viral/metabolism , Reagent Kits, Diagnostic , Republic of Korea , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , Respiratory Syncytial Virus, Human/isolation & purification , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Viral Matrix Proteins/genetics , Viral Proteins/genetics
5.
JCI Insight ; 6(22)2021 11 22.
Article in English | MEDLINE | ID: covidwho-1528615

ABSTRACT

BACKGROUNDInfluenza A virus (IAV) and SARS-CoV-2 are pandemic viruses causing millions of deaths, yet their clinical manifestations are distinctly different.METHODSWith the hypothesis that upper airway immune and epithelial cell responses are also distinct, we performed single-cell RNA sequencing (scRNA-Seq) on nasal wash cells freshly collected from adults with either acute COVID-19 or influenza or from healthy controls. We focused on major cell types and subtypes in a subset of donor samples.ResultsNasal wash cells were enriched for macrophages and neutrophils for both individuals with influenza and those with COVID-19 compared with healthy controls. Hillock-like epithelial cells, M2-like macrophages, and age-dependent B cells were enriched in COVID-19 samples. A global decrease in IFN-associated transcripts in neutrophils, macrophages, and epithelial cells was apparent in COVID-19 samples compared with influenza samples. The innate immune response to SARS-CoV-2 appears to be maintained in macrophages, despite evidence for limited epithelial cell immune sensing. Cell-to-cell interaction analyses revealed a decrease in epithelial cell interactions in COVID-19 and highlighted differences in macrophage-macrophage interactions for COVID-19 and influenza.ConclusionsOur study demonstrates that scRNA-Seq can define host and viral transcriptional activity at the site of infection and reveal distinct local epithelial and immune cell responses for COVID-19 and influenza that may contribute to their divergent disease courses.FundingMassachusetts Consortium on Pathogen Readiness, the Mathers Foundation, and the Department of Defense (W81XWH2110029) "COVID-19 Expansion for AIRe Program."


Subject(s)
COVID-19 , Immunity, Innate , Influenza A virus , Influenza, Human , Macrophages , RNA-Seq , SARS-CoV-2 , Adult , COVID-19/genetics , COVID-19/immunology , Female , Humans , Influenza A virus/genetics , Influenza A virus/immunology , Influenza, Human/genetics , Influenza, Human/immunology , Macrophages/immunology , Macrophages/virology , Male , Nasal Lavage , SARS-CoV-2/genetics , SARS-CoV-2/immunology
6.
Front Immunol ; 12: 770066, 2021.
Article in English | MEDLINE | ID: covidwho-1518490

ABSTRACT

Acute inflammation is a critical host defense response during viral infection. When dysregulated, inflammation drives immunopathology and tissue damage. Excessive, damaging inflammation is a hallmark of both pandemic influenza A virus (IAV) infections and Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) infections. Chronic, low-grade inflammation is also a feature of obesity. In recent years, obesity has been recognized as a growing pandemic with significant mortality and associated costs. Obesity is also an independent risk factor for increased disease severity and death during both IAV and SARS-CoV-2 infection. This review focuses on the effect of obesity on the inflammatory response in the context of viral respiratory infections and how this leads to increased viral pathology. Here, we will review the fundamentals of inflammation, how it is initiated in IAV and SARS-CoV-2 infection and its link to disease severity. We will examine how obesity drives chronic inflammation and trained immunity and how these impact the immune response to IAV and SARS-CoV-2. Finally, we review both medical and non-medical interventions for obesity, how they impact on the inflammatory response and how they could be used to prevent disease severity in obese patients. As projections of global obesity numbers show no sign of slowing down, future pandemic preparedness will require us to consider the metabolic health of the population. Furthermore, if weight-loss alone is insufficient to reduce the risk of increased respiratory virus-related mortality, closer attention must be paid to a patient's history of health, and new therapeutic options identified.


Subject(s)
COVID-19/immunology , Inflammation/immunology , Influenza A virus , Influenza, Human/immunology , Obesity/immunology , SARS-CoV-2 , Animals , Humans , Severity of Illness Index
7.
Sci Rep ; 11(1): 22164, 2021 11 12.
Article in English | MEDLINE | ID: covidwho-1514425

ABSTRACT

The influenza A non-structural protein 1 (NS1) is known for its ability to hinder the synthesis of type I interferon (IFN) during viral infection. Influenza viruses lacking NS1 (ΔNS1) are under clinical development as live attenuated human influenza virus vaccines and induce potent influenza virus-specific humoral and cellular adaptive immune responses. Attenuation of ΔNS1 influenza viruses is due to their high IFN inducing properties, that limit their replication in vivo. This study demonstrates that pre-treatment with a ΔNS1 virus results in an antiviral state which prevents subsequent replication of homologous and heterologous viruses, preventing disease from virus respiratory pathogens, including SARS-CoV-2. Our studies suggest that ΔNS1 influenza viruses could be used for the prophylaxis of influenza, SARS-CoV-2 and other human respiratory viral infections, and that an influenza virus vaccine based on ΔNS1 live attenuated viruses would confer broad protection against influenza virus infection from the moment of administration, first by non-specific innate immune induction, followed by specific adaptive immunity.


Subject(s)
Influenza A virus/immunology , Influenza Vaccines/therapeutic use , Interferon Type I/immunology , Orthomyxoviridae Infections/prevention & control , Vaccines, Attenuated/therapeutic use , Viral Nonstructural Proteins/immunology , Adaptive Immunity , Animals , COVID-19/immunology , COVID-19/prevention & control , Chickens , Gene Deletion , Humans , Influenza A virus/genetics , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Influenza, Human/immunology , Influenza, Human/prevention & control , Mice , Mice, Inbred C57BL , Orthomyxoviridae Infections/immunology , Vaccines, Attenuated/genetics , Vaccines, Attenuated/immunology , Viral Nonstructural Proteins/genetics
8.
BMC Cardiovasc Disord ; 21(1): 528, 2021 11 08.
Article in English | MEDLINE | ID: covidwho-1505900

ABSTRACT

BACKGROUND: The value of mechanical circulatory support (MCS) in cardiogenic shock, especially the combination of the ECMELLA approach (Impella combined with ECMO), remains controversial. CASE PRESENTATION: A previously healthy 33-year-old female patient was submitted to a local emergency department with a flu-like infection and febrile temperatures up to 39 °C. The patient was tested positive for type-A influenza, however negative for SARS-CoV-2. Despite escalated invasive ventilation, refractory hypercapnia (paCO2: 22 kPa) with severe respiratory acidosis (pH: 6.9) and a rising norepinephrine rate occurred within a few hours. Due to a Horovitz-Index < 100, out-of-centre veno-venous extracorporeal membrane oxygenation (vv-ECMO)-implantation was performed. A CT-scan done because of anisocoria revealed an extended dissection of the right vertebral artery. While the initial left ventricular function was normal, echocardiography revealed severe global hypokinesia. After angiographic exclusion of coronary artery stenoses, we geared up LV unloading by additional implantation of an Impella CP and expanded the vv-ECMO to a veno-venous-arterial ECMO (vva-ECMO). Clinically relevant bleeding from the punctured femoral arteries resulted in massive transfusion and was treated by vascular surgery later on. Under continued MCS, LVEF increased to approximately 40% 2 days after the initiation of ECMELLA. After weaning, the Impella CP was explanted at day 5 and the vva-ECMO was removed on day 9, respectively. The patient was discharged in an unaffected neurological condition to rehabilitation 25 days after the initial admission. CONCLUSIONS: This exceptional case exemplifies the importance of aggressive MCS in severe cardiogenic shock, which may be especially promising in younger patients with non-ischaemic cardiomyopathy and potentially reversible causes of cardiogenic shock. This case impressively demonstrates that especially young patients may achieve complete neurological restoration, even though the initial prognosis may appear unfavourable.


Subject(s)
Extracorporeal Membrane Oxygenation/methods , Heart-Assist Devices , Influenza A virus/isolation & purification , Influenza, Human , Respiration, Artificial/methods , Respiratory Insufficiency , Ventricular Dysfunction, Left , Adult , COVID-19/diagnosis , Clinical Deterioration , Critical Care/methods , Echocardiography/methods , Female , Heart Failure/physiopathology , Heart Failure/therapy , Humans , Influenza, Human/complications , Influenza, Human/diagnosis , Influenza, Human/physiopathology , Respiratory Insufficiency/etiology , Respiratory Insufficiency/physiopathology , Respiratory Insufficiency/therapy , SARS-CoV-2 , Serologic Tests/methods , Severity of Illness Index , Shock, Cardiogenic/etiology , Shock, Cardiogenic/physiopathology , Shock, Cardiogenic/therapy , Treatment Outcome , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Left/therapy
9.
BMC Pregnancy Childbirth ; 21(1): 745, 2021 Nov 03.
Article in English | MEDLINE | ID: covidwho-1501992

ABSTRACT

BACKGROUND: Seasonal influenza can circulate in parallel with coronavirus disease (COVID-19) in winter. In the context of COVID-19 pandemic, the risk of co-infection and the burden it poses on healthcare system calls for timely influenza vaccination among pregnant women, who are the priority population recommended for vaccination. We aimed to evaluate the acceptance of influenza vaccination and associated factors among pregnant women during COVID-19 pandemic, provide evidence to improve influenza vaccination among pregnant women, help reduce the risk of infection and alleviate the burden of healthcare system for co-infected patients. METHODS: We conducted a multi-center cross-sectional study among pregnant women in China. Sociodemographic characteristics, health status, knowledge on influenza, attitude towards vaccination, and health beliefs were collected. Locally weighted scatterplot smoothing regression analysis was used to evaluate the trends in the acceptance of influenza vaccine. Logistic regression was applied to identify factors associated with vaccination acceptance. RESULTS: The total acceptance rate was 76.5% (95%CI: 74.8-78.1%) among 2568 pregnant women enrolled. Only 8.3% of the participants had a history of seasonal influenza vaccination. In the logistic regression model, factors associated with the acceptance of influenza vaccine were western region, history of influenza vaccination, high knowledge of influenza infection and vaccination, high level of perceived susceptibility, perceived benefit, cues to action and low level of perceived barriers. Among 23.5% of the participants who had vaccine hesitancy, 48.0% of them were worried about side effect, 35.6% of them lacked confidence of vaccine safety. CONCLUSIONS: Our findings highlighted that tailored strategies and publicity for influenza vaccination in the context of COVID-19 pandemic are warranted to reduce pregnant women's concerns, improve their knowledge, expand vaccine uptake and alleviate pressure for healthcare system.


Subject(s)
COVID-19/epidemiology , Influenza A virus/immunology , Influenza Vaccines/pharmacology , Influenza, Human/prevention & control , Pandemics , Pregnancy Complications, Infectious/prevention & control , Vaccination/methods , Adult , China/epidemiology , Comorbidity , Cross-Sectional Studies , Female , Health Belief Model , Health Knowledge, Attitudes, Practice , Humans , Influenza, Human/epidemiology , Patient Acceptance of Health Care , Pregnancy , Pregnancy Complications, Infectious/epidemiology , SARS-CoV-2 , Seasons , Surveys and Questionnaires
10.
mBio ; 11(2)2020 03 03.
Article in English | MEDLINE | ID: covidwho-1452919

ABSTRACT

Obesity is associated with increased disease severity, elevated viral titers in exhaled breath, and significantly prolonged viral shed during influenza A virus infection. Due to the mutable nature of RNA viruses, we questioned whether obesity could also influence influenza virus population diversity. Here, we show that minor variants rapidly emerge in obese mice. The variants exhibit increased viral replication, resulting in enhanced virulence in wild-type mice. The increased diversity of the viral population correlated with decreased type I interferon responses, and treatment of obese mice with recombinant interferon reduced viral diversity, suggesting that the delayed antiviral response exhibited in obesity permits the emergence of a more virulent influenza virus population. This is not unique to obese mice. Obesity-derived normal human bronchial epithelial (NHBE) cells also showed decreased interferon responses and increased viral replication, suggesting that viral diversity also was impacted in this increasing population.IMPORTANCE Currently, 50% of the adult population worldwide is overweight or obese. In these studies, we demonstrate that obesity not only enhances the severity of influenza infection but also impacts viral diversity. The altered microenvironment associated with obesity supports a more diverse viral quasispecies and affords the emergence of potentially pathogenic variants capable of inducing greater disease severity in lean hosts. This is likely due to the impaired interferon response, which is seen in both obese mice and obesity-derived human bronchial epithelial cells, suggesting that obesity, aside from its impact on influenza virus pathogenesis, permits the stochastic accumulation of potentially pathogenic viral variants, raising concerns about its public health impact as the prevalence of obesity continues to rise.


Subject(s)
Disease Susceptibility , Influenza A virus/physiology , Influenza, Human/etiology , Obesity/complications , Animals , Host-Pathogen Interactions , Humans , Influenza, Human/metabolism , Mice , Mutation , Phenotype , RNA, Viral , Respiratory Mucosa/metabolism , Respiratory Mucosa/virology , Severity of Illness Index , Virulence , Virus Replication
11.
Int J Mol Sci ; 22(21)2021 Oct 27.
Article in English | MEDLINE | ID: covidwho-1487420

ABSTRACT

Tetraspanins are transmembrane glycoproteins that have been shown increasing interest as host factors in infectious diseases. In particular, they were implicated in the pathogenesis of both non-enveloped (human papillomavirus (HPV)) and enveloped (human immunodeficiency virus (HIV), Zika, influenza A virus, (IAV), and coronavirus) viruses through multiple stages of infection, from the initial cell membrane attachment to the syncytium formation and viral particle release. However, the mechanisms by which different tetraspanins mediate their effects vary. This review aimed to compare and contrast the role of tetraspanins in the life cycles of HPV, HIV, Zika, IAV, and coronavirus viruses, which cause the most significant health and economic burdens to society. In doing so, a better understanding of the relative contribution of tetraspanins in virus infection will allow for a more targeted approach in the treatment of these diseases.


Subject(s)
Host-Pathogen Interactions/physiology , Tetraspanins/physiology , Virus Diseases/metabolism , Gene Expression Regulation, Viral , HIV-1/pathogenicity , Humans , Influenza A virus/pathogenicity , Papillomaviridae/pathogenicity , SARS-CoV-2/pathogenicity , Virus Diseases/genetics , Virus Diseases/virology , Virus Internalization , Zika Virus/pathogenicity
12.
J Virol ; 95(15): e0053021, 2021 07 12.
Article in English | MEDLINE | ID: covidwho-1486507

ABSTRACT

Elicitation of lung tissue-resident memory CD8 T cells (TRMs) is a goal of T cell-based vaccines against respiratory viral pathogens, such as influenza A virus (IAV). C-C chemokine receptor type 2 (CCR2)-dependent monocyte trafficking plays an essential role in the establishment of CD8 TRMs in lungs of IAV-infected mice. Here, we used a combination adjuvant-based subunit vaccine strategy that evokes multifaceted (TC1/TC17/TH1/TH17) IAV nucleoprotein-specific lung TRMs to determine whether CCR2 and monocyte infiltration are essential for vaccine-induced TRM development and protective immunity to IAV in lungs. Following intranasal vaccination, neutrophils, monocytes, conventional dendritic cells (DCs), and monocyte-derived dendritic cells internalized and processed vaccine antigen in lungs. We found that basic leucine zipper ATF-like transcription factor 3 (BATF3)-dependent DCs were essential for eliciting T cell responses, but CCR2 deficiency enhanced the differentiation of CD127hi, KLRG-1lo, OX40+ve CD62L+ve, and mucosally imprinted CD69+ve CD103+ve effector and memory CD8 T cells in lungs and airways of vaccinated mice. Mechanistically, increased development of lung TRMs induced by CCR2 deficiency was linked to dampened expression of T-bet but not altered TCF-1 levels or T cell receptor signaling in CD8 T cells. T1/T17 functional programming, parenchymal localization of CD8/CD4 effector and memory T cells, recall T cell responses, and protective immunity to a lethal IAV infection were unaffected in CCR2-deficient mice. Taken together, we identified a negative regulatory role for CCR2 and monocyte trafficking in mucosal imprinting and differentiation of vaccine-induced TRMs. Mechanistic insights from this study may aid the development of T-cell-based vaccines against respiratory viral pathogens, including IAV and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). IMPORTANCE While antibody-based immunity to influenza A virus (IAV) is type and subtype specific, lung- and airway-resident memory T cells that recognize conserved epitopes in the internal viral proteins are known to provide heterosubtypic immunity. Hence, broadly protective IAV vaccines need to elicit robust T cell memory in the respiratory tract. We have developed a combination adjuvant-based IAV nucleoprotein vaccine that elicits strong CD4 and CD8 T cell memory in lungs and protects against H1N1 and H5N1 strains of IAV. In this study, we examined the mechanisms that control vaccine-induced protective memory T cells in the respiratory tract. We found that trafficking of monocytes into lungs might limit the development of antiviral lung-resident memory T cells following intranasal vaccination. These findings suggest that strategies that limit monocyte infiltration can potentiate vaccine-induced frontline T-cell immunity to respiratory viruses, such as IAV and SARS-CoV-2.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Immunity, Mucosal , Immunologic Memory , Influenza A virus/immunology , Influenza Vaccines/immunology , Orthomyxoviridae Infections/immunology , Receptors, CCR2/immunology , T-Lymphocytes, Helper-Inducer/immunology , Animals , Influenza A virus/genetics , Influenza Vaccines/genetics , Influenza Vaccines/pharmacology , Lung/immunology , Mice , Mice, Knockout , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/prevention & control , Receptors, CCR2/genetics
13.
Physiol Rep ; 9(20): e15075, 2021 10.
Article in English | MEDLINE | ID: covidwho-1485552

ABSTRACT

Exercise has substantial health benefits, but the effects of exercise on immune status and susceptibility to respiratory infections are less clear. Furthermore, there is limited research examining the effects of prolonged exercise on local respiratory immunity and antiviral activity. To assess the upper respiratory tract in response to exercise, we collected nasal lavage fluid (NALF) from human subjects (1) at rest, (2) after 45 min of moderate-intensity exercise, and (3) after 180 min of moderate-intensity exercise. To assess immune responses of the lower respiratory tract, we utilized a murine model to examine the effect of exercise duration on bronchoalveolar lavage (BAL) fluid immune cell content and lung gene expression. NALF cell counts did not change after 45 min of exercise, whereas 180 min significantly increased total cells and leukocytes in NALF. Importantly, fold change in NALF leukocytes correlated with the post-exercise fatigue rating in the 180-min exercise condition. The acellular portion of NALF contained strong antiviral activity against Influenza A in both resting and exercise paradigms. In mice undergoing moderate-intensity exercise, BAL total cells and neutrophils decreased in response to 45 or 90 min of exercise. In lung lobes, increased expression of heat shock proteins suggested that cellular stress occurred in response to exercise. However, a broad upregulation of inflammatory genes was not observed, even at 180 min of exercise. This work demonstrates that exercise duration differentially alters the cellularity of respiratory tract fluids, antiviral activity, and gene expression. These changes in local mucosal immunity may influence resistance to respiratory viruses, including influenza or possibly other pathogens in which nasal mucosa plays a protective role, such as rhinovirus or SARS-CoV-2.


Subject(s)
Exercise/physiology , Influenza A virus/immunology , Leukocytes/immunology , Lung/immunology , Nasal Lavage Fluid/immunology , Neutrophils/immunology , Adolescent , Adult , Animals , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/immunology , Female , Gene Expression , Humans , Leukocytes/metabolism , Lung/cytology , Lung/metabolism , Male , Mice , Mice, Inbred BALB C , Nasal Lavage/methods , Nasal Lavage Fluid/cytology , Nasal Mucosa/cytology , Nasal Mucosa/immunology , Nasal Mucosa/metabolism , Neutrophils/metabolism , Time Factors , Young Adult
14.
Nat Immunol ; 22(11): 1416-1427, 2021 11.
Article in English | MEDLINE | ID: covidwho-1475314

ABSTRACT

Ubiquitin-like protein ISG15 (interferon-stimulated gene 15) (ISG15) is a ubiquitin-like modifier induced during infections and involved in host defense mechanisms. Not surprisingly, many viruses encode deISGylating activities to antagonize its effect. Here we show that infection by Zika, SARS-CoV-2 and influenza viruses induce ISG15-modifying enzymes. While influenza and Zika viruses induce ISGylation, SARS-CoV-2 triggers deISGylation instead to generate free ISG15. The ratio of free versus conjugated ISG15 driven by the papain-like protease (PLpro) enzyme of SARS-CoV-2 correlates with macrophage polarization toward a pro-inflammatory phenotype and attenuated antigen presentation. In vitro characterization of purified wild-type and mutant PLpro revealed its strong deISGylating over deubiquitylating activity. Quantitative proteomic analyses of PLpro substrates and secretome from SARS-CoV-2-infected macrophages revealed several glycolytic enzymes previously implicated in the expression of inflammatory genes and pro-inflammatory cytokines, respectively. Collectively, our results indicate that altered free versus conjugated ISG15 dysregulates macrophage responses and probably contributes to the cytokine storms triggered by SARS-CoV-2.


Subject(s)
COVID-19/immunology , Cytokines/metabolism , Inflammation/immunology , Macrophages/immunology , SARS-CoV-2/physiology , Ubiquitins/metabolism , Cell Differentiation , Coronavirus Papain-Like Proteases/metabolism , Cytokines/genetics , Gene Knockdown Techniques , HeLa Cells , Humans , Immune Evasion , Immunity, Innate , Influenza A virus/physiology , Influenza, Human/immunology , Pluripotent Stem Cells/cytology , Ubiquitination , Ubiquitins/genetics , Zika Virus/physiology , Zika Virus Infection/immunology
15.
PLoS Comput Biol ; 17(9): e1009357, 2021 09.
Article in English | MEDLINE | ID: covidwho-1470651

ABSTRACT

Cell culture-derived defective interfering particles (DIPs) are considered for antiviral therapy due to their ability to inhibit influenza A virus (IAV) production. DIPs contain a large internal deletion in one of their eight viral RNAs (vRNAs) rendering them replication-incompetent. However, they can propagate alongside their homologous standard virus (STV) during infection in a competition for cellular and viral resources. So far, experimental and modeling studies for IAV have focused on either the intracellular or the cell population level when investigating the interaction of STVs and DIPs. To examine these levels simultaneously, we conducted a series of experiments using highly different multiplicities of infections for STVs and DIPs to characterize virus replication in Madin-Darby Canine Kidney suspension cells. At several time points post infection, we quantified virus titers, viable cell concentration, virus-induced apoptosis using imaging flow cytometry, and intracellular levels of vRNA and viral mRNA using real-time reverse transcription qPCR. Based on the obtained data, we developed a mathematical multiscale model of STV and DIP co-infection that describes dynamics closely for all scenarios with a single set of parameters. We show that applying high DIP concentrations can shut down STV propagation completely and prevent virus-induced apoptosis. Interestingly, the three observed viral mRNAs (full-length segment 1 and 5, defective interfering segment 1) accumulated to vastly different levels suggesting the interplay between an internal regulation mechanism and a growth advantage for shorter viral RNAs. Furthermore, model simulations predict that the concentration of DIPs should be at least 10000 times higher than that of STVs to prevent the spread of IAV. Ultimately, the model presented here supports a comprehensive understanding of the interactions between STVs and DIPs during co-infection providing an ideal platform for the prediction and optimization of vaccine manufacturing as well as DIP production for therapeutic use.


Subject(s)
Defective Viruses , Influenza A virus , Models, Biological , Orthomyxoviridae Infections/virology , Virus Replication/physiology , Animals , Antiviral Agents , Cell Culture Techniques , Defective Viruses/chemistry , Defective Viruses/genetics , Defective Viruses/pathogenicity , Dogs , Influenza A virus/chemistry , Influenza A virus/genetics , Influenza A virus/pathogenicity , Madin Darby Canine Kidney Cells , RNA, Viral/genetics
16.
Virol J ; 18(1): 202, 2021 10 09.
Article in English | MEDLINE | ID: covidwho-1463255

ABSTRACT

BACKGROUND: The effect of SARS-CoV-2 on existing respiratory pathogens in circulation remains uncertain. This study aimed to assess the impact of SARS-CoV-2 on the prevalence of respiratory pathogens among hospitalized children. METHODS: This study enrolled hospitalized children with acute respiratory infections in Shenzhen Children's Hospital from September to December 2019 (before the COVID-19 epidemic) and those from September to December 2020 (during the COVID-19 epidemic). Nasopharyngeal swabs were collected, and respiratory pathogens were detected using multiplex PCR. The absolute case number and detection rates of 11 pathogens were collected and analyzed. RESULTS: A total of 5696 children with respiratory tract infection received multiplex PCR examination for respiratory pathogens: 2298 from September to December 2019 and 3398 from September to December 2020. At least one pathogen was detected in 1850 (80.5%) patients in 2019, and in 2380 (70.0%) patients in 2020; the detection rate in 2020 was significantly lower than that in 2019.The Influenza A (InfA) detection rate was 5.6% in 2019, but 0% in 2020. The detection rates of Mycoplasma pneumoniae, Human adenovirus, and Human rhinovirus also decreased from 20% (460), 8.9% (206), and 41.8% (961) in 2019 to 1.0% (37), 2.1% (77), and 25.6% (873) in 2020, respectively. In contrast, the detection rates of Human respiratory syncytial virus, Human parainfluenza virus, and Human metapneumovirus increased from 6.6% (153), 9.9% (229), and 0.5% (12) in 2019 to 25.6% (873), 15.5% (530), and 7.2% (247) in 2020, respectively (p < 0.0001). CONCLUSIONS: Successful containment of seasonal influenza as a result of COVID-19 control measures will ensure we are better equipped to deal with future outbreaks of both influenza and COVID-19.Caused by virus competition, the detection rates of Human respiratory syncytial virus, Human parainfluenza virus, and Human metapneumovirus increased in Shenzhen,that reminds us we need to take further monitoring and preventive measures in the next epidemic season.


Subject(s)
Antibiosis , COVID-19/epidemiology , Respiratory Tract Diseases/epidemiology , SARS-CoV-2/isolation & purification , Adenoviruses, Human/genetics , Adenoviruses, Human/isolation & purification , Adolescent , COVID-19/virology , Child , Child, Hospitalized , Child, Preschool , China , Enterovirus/genetics , Enterovirus/isolation & purification , Female , Humans , Infant , Influenza A virus/genetics , Influenza A virus/isolation & purification , Male , Metapneumovirus/genetics , Metapneumovirus/isolation & purification , Mycoplasma pneumoniae/genetics , Mycoplasma pneumoniae/isolation & purification , Nasopharynx/microbiology , Nasopharynx/virology , Prevalence , Respiratory Syncytial Viruses/genetics , Respiratory Syncytial Viruses/isolation & purification , Respiratory Tract Diseases/microbiology , Respiratory Tract Diseases/virology , Respirovirus/genetics , Respirovirus/isolation & purification , SARS-CoV-2/genetics
18.
Eur J Med Chem ; 221: 113494, 2021 Oct 05.
Article in English | MEDLINE | ID: covidwho-1446590

ABSTRACT

In the search for new anti-influenza virus (IV) compounds, we have identified the 1,2,4-triazolo[1,5-a]pyrimidine (TZP) as a very suitable scaffold to obtain compounds able to disrupt IV RNA-dependent RNA polymerase (RdRP) PA-PB1 subunits heterodimerization. In this work, in order to acquire further SAR insights for this class of compounds and identify more potent derivatives, we designed and synthesized additional series of analogues to investigate the role of the substituents around the TZP core. To this aim, we developed four facile and efficient one-step procedures for the synthesis of 5-phenyl-, 6-phenyl- and 7-phenyl-2-amino-[1,2,4]triazolo[1,5-a]pyrimidines, and 2-amino-5-phenyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-ol. Two analogues having the ethyl carboxylate moiety at the C-2 position of the TZP were also prepared in good yields. Then, the scaffolds herein synthesized and two previous scaffolds were functionalized and evaluated for their anti-IAV activity, leading to the identification of compound 22 that showed both anti-PA-PB1 (IC50 = 19.5 µM) and anti-IAV activity (EC50 = 16 µM) at non-toxic concentrations, thus resulting among the most active TZP derivatives reported to date by us. A selection of the synthesized compounds, along with a set of in-house available analogues, was also tested against SARS-CoV-2. The most promising compound 49 from this series displayed an EC50 value of 34.47 µM, highlighting the potential of the TPZ scaffold in the search for anti-CoV agents.


Subject(s)
Antiviral Agents/pharmacology , Protein Multimerization/drug effects , Pyrimidines/pharmacology , RNA-Dependent RNA Polymerase/antagonists & inhibitors , Triazoles/pharmacology , Viral Proteins/antagonists & inhibitors , Animals , Antiviral Agents/chemical synthesis , Chlorocebus aethiops , Dogs , Drug Design , HEK293 Cells , Humans , Influenza A virus/drug effects , Madin Darby Canine Kidney Cells , Microbial Sensitivity Tests , Pyrimidines/chemical synthesis , SARS-CoV-2/drug effects , Triazoles/chemical synthesis , Vero Cells
19.
J Med Virol ; 93(10): 5998-6007, 2021 10.
Article in English | MEDLINE | ID: covidwho-1432442

ABSTRACT

In the context of the coronavirus disease 2019 pandemic, we investigated the epidemiological and clinical characteristics of a young patient infected by avian influenza A (H5N6) virus in Anhui Province, East China, and analyzed genomic features of the pathogen in 2020. Through the cross-sectional investigation of external environment monitoring (December 29-31, 2020), 1909 samples were collected from Fuyang City. It was found that the positive rate of H5N6 was higher than other areas obviously in Tianma poultry market, where the case appeared. In addition, dual coinfections were detected with a 0.057% polymerase chain reaction positive rate the surveillance years. The virus was the clade 2.3.4.4, which was most likely formed by genetic reassortment between H5N6 and H9N2 viruses. This study found that the evolution rates of the hemagglutinin and neuraminidase genes of the virus were higher than those of common seasonal influenza viruses. The virus was still highly pathogenic to poultry and had a preference for avian receptor binding.


Subject(s)
COVID-19/epidemiology , Influenza A virus/isolation & purification , Influenza in Birds/virology , Influenza, Human/virology , Animals , Child, Preschool , China , Female , Genome, Viral/genetics , Humans , Influenza A virus/classification , Influenza A virus/genetics , Influenza, Human/diagnosis , Mutation , Phylogeny , Poultry/virology , Reassortant Viruses/classification , Reassortant Viruses/genetics , Reassortant Viruses/isolation & purification , SARS-CoV-2 , Viral Proteins/genetics
20.
J Med Virol ; 93(10): 5798-5804, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1432412

ABSTRACT

Rapid diagnostics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are paramount for reducing the spread of the current pandemic. During additional seasonal epidemics with influenza A/B and respiratory syncytial virus (RSV), the clinical signs and symptoms cannot be distinguished easily from SARS-CoV-2. Therefore, a new assay combining four targets in the form of the new Xpert Xpress SARS-CoV-2/Flu/RSV assay was evaluated. The assay was compared to the Xpert Xpress SARS-CoV-2, Xpert Xpress Flu/RSV, Seegene Flu/RSV, influenza A/B r-gene® and RSV/hMPV r-gene®. A total of 295 nasopharyngeal and throat swabs were tested at four institutes throughout Europe including 72 samples positive for SARS-CoV-2, 65 for influenza A, 47 for influenza B, and 77 for RSV. The sensitivity of the new assay was above 95% for all targets, with the highest for SARS-CoV-2 (97.2%). The overall correlation of SARS-CoV-2 Ct values between Xpert Xpress SARS-CoV-2 assay and Xpert Xpress SARS-CoV-2/Flu/RSV assay was high. The agreement between Ct values above 30 showed the multiplex giving higher Ct values for SARS-CoV-2 on average than the singleplex assay. In conclusion, the new assay is a rapid and reliable alternative with less hands-on time for the detection of not one, but four upper respiratory tract pathogens that may circulate at the same time.


Subject(s)
Influenza A virus/isolation & purification , Influenza B virus/isolation & purification , Respiratory Syncytial Virus, Human/isolation & purification , Respiratory Tract Infections/diagnosis , SARS-CoV-2/isolation & purification , COVID-19/diagnosis , COVID-19 Nucleic Acid Testing , Europe/epidemiology , Humans , Influenza, Human/diagnosis , Molecular Diagnostic Techniques , Multiplex Polymerase Chain Reaction , Nasopharynx/virology , Respiratory Syncytial Virus Infections/diagnosis , Respiratory Tract Infections/virology , SARS-CoV-2/genetics , Sensitivity and Specificity
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