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3.
PLoS Pathog ; 17(10): e1009928, 2021 10.
Article in English | MEDLINE | ID: covidwho-1484868

ABSTRACT

Non-specific protective effects of certain vaccines have been reported, and long-term boosting of innate immunity, termed trained immunity, has been proposed as one of the mechanisms mediating these effects. Several epidemiological studies suggested cross-protection between influenza vaccination and COVID-19. In a large academic Dutch hospital, we found that SARS-CoV-2 infection was less common among employees who had received a previous influenza vaccination: relative risk reductions of 37% and 49% were observed following influenza vaccination during the first and second COVID-19 waves, respectively. The quadrivalent inactivated influenza vaccine induced a trained immunity program that boosted innate immune responses against various viral stimuli and fine-tuned the anti-SARS-CoV-2 response, which may result in better protection against COVID-19. Influenza vaccination led to transcriptional reprogramming of monocytes and reduced systemic inflammation. These epidemiological and immunological data argue for potential benefits of influenza vaccination against COVID-19, and future randomized trials are warranted to test this possibility.


Subject(s)
COVID-19/immunology , Cross Protection/physiology , Immunity, Innate/physiology , Influenza Vaccines/administration & dosage , COVID-19/epidemiology , COVID-19/prevention & control , Cytokines/immunology , Cytokines/metabolism , Down-Regulation , Imidazoles/immunology , Incidence , Influenza Vaccines/immunology , Netherlands/epidemiology , Personnel, Hospital , Poly I-C/immunology , Proteomics , Risk Factors , Sequence Analysis, RNA
4.
mBio ; 12(5): e0233521, 2021 10 26.
Article in English | MEDLINE | ID: covidwho-1430167

ABSTRACT

Newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic with astonishing mortality and morbidity. The high replication and transmission of SARS-CoV-2 are remarkably distinct from those of previous closely related coronaviruses, and the underlying molecular mechanisms remain unclear. The innate immune defense is a physical barrier that restricts viral replication. We report here that the SARS-CoV-2 Nsp5 main protease targets RIG-I and mitochondrial antiviral signaling (MAVS) protein via two distinct mechanisms for inhibition. Specifically, Nsp5 cleaves off the 10 most-N-terminal amino acids from RIG-I and deprives it of the ability to activate MAVS, whereas Nsp5 promotes the ubiquitination and proteosome-mediated degradation of MAVS. As such, Nsp5 potently inhibits interferon (IFN) induction by double-stranded RNA (dsRNA) in an enzyme-dependent manner. A synthetic small-molecule inhibitor blunts the Nsp5-mediated destruction of cellular RIG-I and MAVS and processing of SARS-CoV-2 nonstructural proteins, thus restoring the innate immune response and impeding SARS-CoV-2 replication. This work offers new insight into the immune evasion strategy of SARS-CoV-2 and provides a potential antiviral agent to treat CoV disease 2019 (COVID-19) patients. IMPORTANCE The ongoing COVID-19 pandemic is caused by SARS-CoV-2, which is rapidly evolving with better transmissibility. Understanding the molecular basis of the SARS-CoV-2 interaction with host cells is of paramount significance, and development of antiviral agents provides new avenues to prevent and treat COVID-19 diseases. This study describes a molecular characterization of innate immune evasion mediated by the SARS-CoV-2 Nsp5 main protease and subsequent development of a small-molecule inhibitor.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Coronavirus 3C Proteases/metabolism , DEAD Box Protein 58/metabolism , Receptors, Immunologic/metabolism , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , A549 Cells , Adaptor Proteins, Signal Transducing/genetics , Animals , Caco-2 Cells , Coronavirus 3C Proteases/genetics , DEAD Box Protein 58/genetics , Enzyme-Linked Immunosorbent Assay , HCT116 Cells , HEK293 Cells , Humans , Immunity, Innate/genetics , Immunity, Innate/physiology , Immunoblotting , Interferon Type I/metabolism , Mice , Receptors, Immunologic/genetics , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/genetics , Signal Transduction/physiology , Ubiquitination , Virus Replication/genetics , Virus Replication/physiology
5.
J Exp Med ; 218(8)2021 08 02.
Article in English | MEDLINE | ID: covidwho-1387679

ABSTRACT

Initial replication of SARS-CoV-2 in the upper respiratory tract is required to establish infection, and the replication level correlates with the likelihood of viral transmission. Here, we examined the role of host innate immune defenses in restricting early SARS-CoV-2 infection using transcriptomics and biomarker-based tracking in serial patient nasopharyngeal samples and experiments with airway epithelial organoids. SARS-CoV-2 initially replicated exponentially, with a doubling time of ∼6 h, and induced interferon-stimulated genes (ISGs) in the upper respiratory tract, which rose with viral replication and peaked just as viral load began to decline. Rhinovirus infection before SARS-CoV-2 exposure accelerated ISG responses and prevented SARS-CoV-2 replication. Conversely, blocking ISG induction during SARS-CoV-2 infection enhanced viral replication from a low infectious dose. These results show that the activity of ISG-mediated defenses at the time of SARS-CoV-2 exposure impacts infection progression and that the heterologous antiviral response induced by a different virus can protect against SARS-CoV-2.


Subject(s)
COVID-19/immunology , COVID-19/virology , Immunity, Innate/physiology , Nasopharynx/virology , Adult , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme 2/genetics , Case-Control Studies , Chemokine CXCL10/metabolism , Disease Susceptibility/immunology , Female , Gene Expression Profiling , Host-Pathogen Interactions/physiology , Humans , Interferons/genetics , Interferons/immunology , Interferons/metabolism , Male , Middle Aged , Picornaviridae Infections/immunology , Picornaviridae Infections/virology , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Viral Load , Virus Replication
6.
J Neurovirol ; 27(4): 531-541, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1384682

ABSTRACT

The conjugation of small ubiquitin-like modifier (SUMO) proteins to substrates is a well-described post-translational modification that regulates protein activity, subcellular localization, and protein-protein interactions for a variety of downstream cellular activities. Several studies describe SUMOylation as an essential post-translational modification for successful viral infection across a broad range of viruses, including RNA and DNA viruses, both enveloped and un-enveloped. These viruses include but are not limited to herpes viruses, human immunodeficiency virus-1, and coronaviruses. In addition to the SUMOylation of viral proteins during infection, evidence shows that viruses manipulate the SUMO pathway for host protein SUMOylation. SUMOylation of host and viral proteins greatly impacts host innate immunity through viral manipulation of the host SUMOylation machinery to promote viral replication and pathogenesis. Other post-translational modifications like phosphorylation can also modulate SUMO function. For example, phosphorylation of COUP-TF interacting protein 2 (CTIP2) leads to its SUMOylation and subsequent proteasomal degradation. The SUMOylation of CTIP2 and subsequent degradation prevents CTIP2-mediated recruitment of a multi-enzymatic complex to the HIV-1 promoter that usually prevents the transcription of integrated viral DNA. Thus, the "SUMO switch" could have implications for CTIP2-mediated transcriptional repression of HIV-1 in latency and viral persistence. In this review, we describe the consequences of SUMO in innate immunity and then focus on the various ways that viral pathogens have evolved to hijack the conserved SUMO machinery. Increased understanding of the many roles of SUMOylation in viral infections can lead to novel insight into the regulation of viral pathogenesis with the potential to uncover new targets for antiviral therapies.


Subject(s)
Host-Pathogen Interactions/physiology , Immunity, Innate/physiology , Sumoylation/physiology , Virus Diseases/immunology , Virus Diseases/metabolism , Animals , Humans , Protein Processing, Post-Translational , SUMO-1 Protein/immunology , SUMO-1 Protein/metabolism
8.
Nat Cell Biol ; 23(7): 718-732, 2021 07.
Article in English | MEDLINE | ID: covidwho-1303773

ABSTRACT

Patients with Coronavirus disease 2019 exhibit low expression of interferon-stimulated genes, contributing to a limited antiviral response. Uncovering the underlying mechanism of innate immune suppression and rescuing the innate antiviral response remain urgent issues in the current pandemic. Here we identified that the dimerization domain of the SARS-CoV-2 nucleocapsid protein (SARS2-NP) is required for SARS2-NP to undergo liquid-liquid phase separation with RNA, which inhibits Lys63-linked poly-ubiquitination and aggregation of MAVS and thereby suppresses the innate antiviral immune response. Mice infected with an RNA virus carrying SARS2-NP exhibited reduced innate immunity, an increased viral load and high morbidity. Notably, we identified SARS2-NP acetylation at Lys375 by host acetyltransferase and reported frequently occurring acetylation-mimicking mutations of Lys375, all of which impaired SARS2-NP liquid-liquid phase separation with RNA. Importantly, a peptide targeting the dimerization domain was screened out to disrupt the SARS2-NP liquid-liquid phase separation and demonstrated to inhibit SARS-CoV-2 replication and rescue innate antiviral immunity both in vitro and in vivo.


Subject(s)
Nucleocapsid Proteins/immunology , Nucleocapsid Proteins/metabolism , SARS-CoV-2/genetics , Animals , Immunity, Innate/immunology , Immunity, Innate/physiology , Mice , Nucleocapsid Proteins/genetics , RNA Viruses/genetics , SARS-CoV-2/physiology
9.
Exp Biol Med (Maywood) ; 246(21): 2324-2331, 2021 11.
Article in English | MEDLINE | ID: covidwho-1301821

ABSTRACT

COVID-19 disease has been a problem in today's society, which has worldwide effects on different areas, especially on the economy; also, from a health perspective, the disease affects the daily life quality. Physical activity is one major positive factor with regard to enhancing life quality, as it can improve the whole psychological, social, and physical health conditions. Current measures such as social distancing are focused on preventing the viral spread. However, the consequences on other areas are yet to be investigated. Elderly, people with chronic diseases, obese, and others benefit largely from exercise from the perspective of improved health, and preventive measures can drastically improve daily living. In this article, we elaborate the effects of exercise on the immune system and the possible strategies that can be implemented toward greater preventive potential.


Subject(s)
COVID-19/prevention & control , Exercise/physiology , Primary Prevention/methods , Body Composition/physiology , Comorbidity , Exercise/psychology , Humans , Immunity, Innate/physiology , Physical Distancing , Quality of Life/psychology , SARS-CoV-2
10.
Nat Rev Nephrol ; 17(11): 751-764, 2021 11.
Article in English | MEDLINE | ID: covidwho-1297305

ABSTRACT

Although respiratory failure and hypoxaemia are the main manifestations of COVID-19, kidney involvement is also common. Available evidence supports a number of potential pathophysiological pathways through which acute kidney injury (AKI) can develop in the context of SARS-CoV-2 infection. Histopathological findings have highlighted both similarities and differences between AKI in patients with COVID-19 and in those with AKI in non-COVID-related sepsis. Acute tubular injury is common, although it is often mild, despite markedly reduced kidney function. Systemic haemodynamic instability very likely contributes to tubular injury. Despite descriptions of COVID-19 as a cytokine storm syndrome, levels of circulating cytokines are often lower in patients with COVID-19 than in patients with acute respiratory distress syndrome with causes other than COVID-19. Tissue inflammation and local immune cell infiltration have been repeatedly observed and might have a critical role in kidney injury, as might endothelial injury and microvascular thrombi. Findings of high viral load in patients who have died with AKI suggest a contribution of viral invasion in the kidneys, although the issue of renal tropism remains controversial. An impaired type I interferon response has also been reported in patients with severe COVID-19. In light of these observations, the potential pathophysiological mechanisms of COVID-19-associated AKI may provide insights into therapeutic strategies.


Subject(s)
Acute Kidney Injury/physiopathology , Acute Kidney Injury/virology , COVID-19/physiopathology , Adaptive Immunity/physiology , Biopsy , Complement System Proteins , Drug-Related Side Effects and Adverse Reactions , Endothelium, Vascular/physiopathology , Extracorporeal Membrane Oxygenation , Hematuria/physiopathology , Humans , Immunity, Humoral/physiology , Immunity, Innate/physiology , Immunosenescence , Inflammation/physiopathology , Inflammation/virology , Interferon Type I/physiology , Kidney/pathology , Kidney/virology , Proteinuria/physiopathology , Severity of Illness Index , Viral Load
11.
Nat Commun ; 12(1): 2735, 2021 05 12.
Article in English | MEDLINE | ID: covidwho-1241460

ABSTRACT

Inflammasomes are filamentous signaling platforms integral to innate immunity. Currently, little is known about how these structurally similar filaments recognize and distinguish one another. A cryo-EM structure of the AIM2PYD filament reveals that the architecture of the upstream filament is essentially identical to that of the adaptor ASCPYD filament. In silico simulations using Rosetta and molecular dynamics followed by biochemical and cellular experiments consistently demonstrate that individual filaments assemble bidirectionally. By contrast, the recognition between AIM2 and ASC requires at least one to be oligomeric and occurs in a head-to-tail manner. Using in silico mutagenesis as a guide, we also identify specific axial and lateral interfaces that dictate the recognition and distinction between AIM2 and ASC filaments. Together, the results here provide a robust framework for delineating the signaling specificity and order of inflammasomes.


Subject(s)
CARD Signaling Adaptor Proteins/metabolism , DNA-Binding Proteins/metabolism , Immunity, Innate/physiology , Inflammasomes/metabolism , CARD Signaling Adaptor Proteins/genetics , Cryoelectron Microscopy , DNA-Binding Proteins/genetics , HEK293 Cells , Humans , Molecular Dynamics Simulation , Mutation/genetics , Protein Structure, Secondary , Signal Transduction/physiology
12.
Cells ; 10(6)2021 06 11.
Article in English | MEDLINE | ID: covidwho-1270009

ABSTRACT

Neutrophils are the most abundant circulating innate immune cells and comprise the first immune defense line, as they are the most rapidly recruited cells at sites of infection or inflammation. Their main microbicidal mechanisms are degranulation, phagocytosis, cytokine secretion and the formation of extracellular traps. Neutrophil extracellular traps (NETs) are a microbicidal mechanism that involves neutrophil death. Since their discovery, in vitro and in vivo neutrophils have been challenged with a range of stimuli capable of inducing or inhibiting NET formation, with the objective to understand its function and regulation in health and disease. These networks composed of DNA and granular components are capable of immobilizing and killing pathogens. They comprise enzymes such as myeloperoxidase, elastase, cathepsin G, acid hydrolases and cationic peptides, all with antimicrobial and antifungal activity. Therefore, the excessive formation of NETs can also lead to tissue damage and promote local and systemic inflammation. Based on this concept, in this review, we focus on the role of NETs in different infectious and inflammatory diseases of the mucosal epithelia and skin.


Subject(s)
Extracellular Traps/physiology , Mucous Membrane/immunology , Skin Diseases/immunology , Epithelial Cells/immunology , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate/physiology , Neutrophils/immunology , Neutrophils/physiology , Skin Diseases/pathology
13.
J Exp Med ; 218(8)2021 08 02.
Article in English | MEDLINE | ID: covidwho-1269483

ABSTRACT

Our understanding of protective versus pathological immune responses to SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), is limited by inadequate profiling of patients at the extremes of the disease severity spectrum. Here, we performed multi-omic single-cell immune profiling of 64 COVID-19 patients across the full range of disease severity, from outpatients with mild disease to fatal cases. Our transcriptomic, epigenomic, and proteomic analyses revealed widespread dysfunction of peripheral innate immunity in severe and fatal COVID-19, including prominent hyperactivation signatures in neutrophils and NK cells. We also identified chromatin accessibility changes at NF-κB binding sites within cytokine gene loci as a potential mechanism for the striking lack of pro-inflammatory cytokine production observed in monocytes in severe and fatal COVID-19. We further demonstrated that emergency myelopoiesis is a prominent feature of fatal COVID-19. Collectively, our results reveal disease severity-associated immune phenotypes in COVID-19 and identify pathogenesis-associated pathways that are potential targets for therapeutic intervention.


Subject(s)
COVID-19/blood , COVID-19/immunology , Immunity, Innate/physiology , Adult , Aged , COVID-19/genetics , COVID-19/mortality , Case-Control Studies , Cytokines/genetics , Epigenesis, Genetic , Female , Hematopoiesis , Humans , Killer Cells, Natural/pathology , Killer Cells, Natural/virology , Male , Middle Aged , Monocytes/pathology , Monocytes/virology , NF-kappa B/metabolism , Neutrophils/pathology , Neutrophils/virology , Proteomics , Severity of Illness Index , Single-Cell Analysis
14.
PLoS Pathog ; 17(5): e1009229, 2021 05.
Article in English | MEDLINE | ID: covidwho-1239922

ABSTRACT

While MERS-CoV (Middle East respiratory syndrome Coronavirus) provokes a lethal disease in humans, camelids, the main virus reservoir, are asymptomatic carriers, suggesting a crucial role for innate immune responses in controlling the infection. Experimentally infected camelids clear infectious virus within one week and mount an effective adaptive immune response. Here, transcription of immune response genes was monitored in the respiratory tract of MERS-CoV infected alpacas. Concomitant to the peak of infection, occurring at 2 days post inoculation (dpi), type I and III interferons (IFNs) were maximally transcribed only in the nasal mucosa of alpacas, while interferon stimulated genes (ISGs) were induced along the whole respiratory tract. Simultaneous to mild focal infiltration of leukocytes in nasal mucosa and submucosa, upregulation of the anti-inflammatory cytokine IL10 and dampened transcription of pro-inflammatory genes under NF-κB control were observed. In the lung, early (1 dpi) transcription of chemokines (CCL2 and CCL3) correlated with a transient accumulation of mainly mononuclear leukocytes. A tight regulation of IFNs in lungs with expression of ISGs and controlled inflammatory responses, might contribute to virus clearance without causing tissue damage. Thus, the nasal mucosa, the main target of MERS-CoV in camelids, seems central in driving an efficient innate immune response based on triggering ISGs as well as the dual anti-inflammatory effects of type III IFNs and IL10.


Subject(s)
Camelids, New World , Coronavirus Infections/immunology , Interferon Type I/metabolism , Interferons/metabolism , Middle East Respiratory Syndrome Coronavirus/immunology , Animals , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Camelids, New World/immunology , Camelids, New World/metabolism , Camelids, New World/virology , Chlorocebus aethiops , Coronavirus Infections/metabolism , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Disease Reservoirs/veterinary , Disease Resistance/drug effects , Disease Resistance/genetics , Disease Resistance/immunology , Gene Expression Regulation , Immunity, Innate/physiology , Inflammation/immunology , Inflammation/metabolism , Inflammation/veterinary , Inflammation/virology , Interferon Type I/genetics , Interferon Type I/pharmacology , Interferons/genetics , Interferons/pharmacology , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/physiology , Nasal Mucosa/drug effects , Nasal Mucosa/immunology , Nasal Mucosa/metabolism , Nasal Mucosa/virology , Respiratory System/drug effects , Respiratory System/immunology , Respiratory System/metabolism , Respiratory System/virology , Vero Cells , Viral Load/drug effects , Virus Replication/drug effects
15.
Cell Transplant ; 30: 9636897211010632, 2021.
Article in English | MEDLINE | ID: covidwho-1216873

ABSTRACT

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) first emerged in December 2019 in Wuhan, China, and has since spread rapidly worldwide. As researchers seek to learn more about COVID-19, the disease it causes, this novel virus continues to infect and kill. Despite the socioeconomic impacts of SARS-CoV-2 infections and likelihood of future outbreaks of other pathogenic coronaviruses, options to prevent or treat coronavirus infections remain limited. In current clinical trials, potential coronavirus treatments focusing on killing the virus or on preventing infection using vaccines largely ignore the host immune response. The relatively small body of current research on the virus indicates pathological responses by the immune system as the leading cause for much of the morbidity and mortality caused by COVID-19. In this review, we investigated the host innate and adaptive immune responses against COVID-19, collated information on recent COVID-19 experimental data, and summarized the systemic immune responses to and histopathology of SARS-CoV-2 infection. Finally, we summarized the immune-related biomarkers to define patients with high-risk and worst-case outcomes, and identified the possible usefulness of inflammatory markers as potential immunotherapeutic targets. This review provides an overview of current knowledge on COVID-19 and the symptomatological differences between healthy, convalescent, and severe cohorts, while offering research directions for alternative immunoregulation therapeutic targets.


Subject(s)
Adaptive Immunity/physiology , Immunity, Innate/physiology , SARS-CoV-2/immunology , Biomarkers , Humans
18.
Cytokine Growth Factor Rev ; 58: 32-48, 2021 04.
Article in English | MEDLINE | ID: covidwho-1163617

ABSTRACT

The coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), appears with a wide spectrum of mild-to-critical clinical complications. Many clinical and experimental findings suggest the role of inflammatory mechanisms in the immunopathology of COVID-19. Hence, cellular and molecular mediators of the immune system can be potential targets for predicting, monitoring, and treating the progressive complications of COVID-19. In this review, we assess the latest cellular and molecular data on the immunopathology of COVID-19 according to the pathological evidence (e.g., mucus and surfactants), dysregulations of pro- and anti-inflammatory mediators (e.g., cytokines and chemokines), and impairments of innate and acquired immune system functions (e.g., mononuclear cells, neutrophils and antibodies). Furthermore, we determine the significance of immune biomarkers for predicting, monitoring, and treating the progressive complications of COVID-19. We also discuss the clinical importance of recent immune biomarkers in COVID-19, and at the end of each section, recent clinical trials in immune biomarkers for COVID-19 are mentioned.


Subject(s)
Biomarkers/blood , COVID-19/diagnosis , COVID-19/therapy , Immunity, Innate/physiology , Monitoring, Physiologic/methods , Biomarkers/analysis , COVID-19/blood , COVID-19/complications , Chemokines/analysis , Chemokines/blood , Cytokine Release Syndrome/diagnosis , Cytokine Release Syndrome/etiology , Cytokine Release Syndrome/therapy , Cytokines/analysis , Cytokines/blood , Humans , Prognosis , Respiratory Distress Syndrome/diagnosis , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/therapy , SARS-CoV-2/physiology
19.
Bosn J Basic Med Sci ; 21(5): 515-527, 2021 Oct 01.
Article in English | MEDLINE | ID: covidwho-1134549

ABSTRACT

Coronavirus disease-19 (COVID-19) is an extremely infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has become a major global health concern. The induction of a coordinated immune response is crucial to the elimination of any pathogenic infection. However, SARS-CoV-2 can modulate the host immune system to favor viral adaptation and persistence within the host. The virus can counteract type I interferon (IFN-I) production, attenuating IFN-I signaling pathway activation and disrupting antigen presentation. Simultaneously, SARS-CoV-2 infection can enhance apoptosis and the production of inflammatory mediators, which ultimately results in increased disease severity. SARS-CoV-2 produces an array of effector molecules, including nonstructural proteins (NSPs) and open-reading frames (ORFs) accessory proteins. We describe the complex molecular interplay of SARS-CoV-2 NSPs and accessory proteins with the host's signaling mediating immune evasion in the current review. In addition, the crucial role played by immunomodulation therapy to address immune evasion is discussed. Thus, the current review can provide new directions for the development of vaccines and specific therapies.


Subject(s)
COVID-19/immunology , Immune Evasion/physiology , Immunity, Innate/physiology , SARS-CoV-2/pathogenicity , Viral Nonstructural Proteins/physiology , Viral Regulatory and Accessory Proteins/physiology , Humans
20.
Aging (Albany NY) ; 13(2): 1566-1567, 2021 01 27.
Article in English | MEDLINE | ID: covidwho-1079868
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