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1.
Int Immunopharmacol ; 101(Pt B): 108255, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1549847

ABSTRACT

The coronavirus disease (COVID-19) has once again reminded us of the significance of host immune response and consequential havocs of the immune dysregulation. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) inflicts severe complications to the infected host, including cough, dyspnoea, fever, septic shock, acute respiratory distress syndrome (ARDs), and multiple organ failure. These manifestations are the consequence of the dysregulated immune system, which gives rise to excessive and unattended production of pro-inflammatory mediators. Elevated circulatory cytokine and chemokine levels are accompanied by spontaneous haemorrhage, thrombocytopenia and systemic inflammation, which are the cardinal features of life-threatening cytokine storm syndrome in advanced COVID-19 diseases. Coronavirus hijacked NF-kappa B (NF-κB) is responsible for upregulating the expressions of inflammatory cytokine, chemokine, alarmins and inducible enzymes, which paves the pathway for cytokine storm. Given the scenario, the systemic approach of simultaneous inhibition of NF-κB offers an attractive therapeutic intervention. Targeted therapies with proteasome inhibitor (VL-01, bortezomib, carfilzomib and ixazomib), bruton tyrosine kinase inhibitor (acalabrutinib), nucleotide analogue (remdesivir), TNF-α monoclonal antibodies (infliximab and adalimumab), N-acetylcysteine and corticosteroids (dexamethasone), focusing the NF-κB inhibition have demonstrated effectiveness in terms of the significant decrease in morbidity and mortality in severe COVID-19 patients. Hence, this review highlights the activation, signal transduction and cross-talk of NF-κB with regard to cytokine storm in COVID-19. Moreover, the development of therapeutic strategies based on NF-κB inhibition are also discussed herein.


Subject(s)
COVID-19/immunology , Cytokine Release Syndrome/immunology , NF-kappa B/immunology , SARS-CoV-2 , Animals , Chromosomes, Human, X/immunology , Exophthalmos , Gonadal Steroid Hormones/immunology , Humans , Signal Transduction
2.
Int Immunopharmacol ; 101(Pt B): 108255, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1482656

ABSTRACT

The coronavirus disease (COVID-19) has once again reminded us of the significance of host immune response and consequential havocs of the immune dysregulation. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) inflicts severe complications to the infected host, including cough, dyspnoea, fever, septic shock, acute respiratory distress syndrome (ARDs), and multiple organ failure. These manifestations are the consequence of the dysregulated immune system, which gives rise to excessive and unattended production of pro-inflammatory mediators. Elevated circulatory cytokine and chemokine levels are accompanied by spontaneous haemorrhage, thrombocytopenia and systemic inflammation, which are the cardinal features of life-threatening cytokine storm syndrome in advanced COVID-19 diseases. Coronavirus hijacked NF-kappa B (NF-κB) is responsible for upregulating the expressions of inflammatory cytokine, chemokine, alarmins and inducible enzymes, which paves the pathway for cytokine storm. Given the scenario, the systemic approach of simultaneous inhibition of NF-κB offers an attractive therapeutic intervention. Targeted therapies with proteasome inhibitor (VL-01, bortezomib, carfilzomib and ixazomib), bruton tyrosine kinase inhibitor (acalabrutinib), nucleotide analogue (remdesivir), TNF-α monoclonal antibodies (infliximab and adalimumab), N-acetylcysteine and corticosteroids (dexamethasone), focusing the NF-κB inhibition have demonstrated effectiveness in terms of the significant decrease in morbidity and mortality in severe COVID-19 patients. Hence, this review highlights the activation, signal transduction and cross-talk of NF-κB with regard to cytokine storm in COVID-19. Moreover, the development of therapeutic strategies based on NF-κB inhibition are also discussed herein.


Subject(s)
COVID-19/immunology , Cytokine Release Syndrome/immunology , NF-kappa B/immunology , SARS-CoV-2 , Animals , Chromosomes, Human, X/immunology , Exophthalmos , Gonadal Steroid Hormones/immunology , Humans , Signal Transduction
3.
J Biol Chem ; 296: 100630, 2021.
Article in English | MEDLINE | ID: covidwho-1333548

ABSTRACT

Unchecked inflammation can result in severe diseases with high mortality, such as macrophage activation syndrome (MAS). MAS and associated cytokine storms have been observed in COVID-19 patients exhibiting systemic hyperinflammation. Interleukin-18 (IL-18), a proinflammatory cytokine belonging to the IL-1 family, is elevated in both MAS and COVID-19 patients, and its level is known to correlate with the severity of COVID-19 symptoms. IL-18 binds its specific receptor IL-1 receptor 5 (IL-1R5, also known as IL-18 receptor alpha chain), leading to the recruitment of the coreceptor, IL-1 receptor 7 (IL-1R7, also known as IL-18 receptor beta chain). This heterotrimeric complex then initiates downstream signaling, resulting in systemic and local inflammation. Here, we developed a novel humanized monoclonal anti-IL-1R7 antibody to specifically block the activity of IL-18 and its inflammatory signaling. We characterized the function of this antibody in human cell lines, in freshly obtained peripheral blood mononuclear cells (PBMCs) and in human whole blood cultures. We found that the anti-IL-1R7 antibody significantly suppressed IL-18-mediated NFκB activation, reduced IL-18-stimulated IFNγ and IL-6 production in human cell lines, and reduced IL-18-induced IFNγ, IL-6, and TNFα production in PBMCs. Moreover, the anti-IL-1R7 antibody significantly inhibited LPS- and Candida albicans-induced IFNγ production in PBMCs, as well as LPS-induced IFNγ production in whole blood cultures. Our data suggest that blocking IL-1R7 could represent a potential therapeutic strategy to specifically modulate IL-18 signaling and may warrant further investigation into its clinical potential for treating IL-18-mediated diseases, including MAS and COVID-19.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Antibodies, Monoclonal/pharmacology , Antibodies, Neutralizing/pharmacology , Immunologic Factors/pharmacology , Interleukin-18/genetics , Receptors, Interleukin-18/genetics , Anti-Inflammatory Agents/metabolism , Antibodies, Monoclonal/biosynthesis , Antibodies, Neutralizing/biosynthesis , COVID-19/drug therapy , Candida albicans/growth & development , Candida albicans/pathogenicity , Gene Expression Regulation , HEK293 Cells , Humans , Immunologic Factors/biosynthesis , Inflammation , Interferon-gamma/genetics , Interferon-gamma/immunology , Interleukin-18/immunology , Interleukin-6/genetics , Interleukin-6/immunology , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/microbiology , Lipopolysaccharides/antagonists & inhibitors , Lipopolysaccharides/pharmacology , Macrophage Activation Syndrome/drug therapy , NF-kappa B/genetics , NF-kappa B/immunology , Primary Cell Culture , Receptors, Interleukin-18/antagonists & inhibitors , Receptors, Interleukin-18/immunology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunology
4.
PLoS One ; 16(6): e0253089, 2021.
Article in English | MEDLINE | ID: covidwho-1282298

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a devastating global pandemic, infecting over 43 million people and claiming over 1 million lives, with these numbers increasing daily. Therefore, there is urgent need to understand the molecular mechanisms governing SARS-CoV-2 pathogenesis, immune evasion, and disease progression. Here, we show that SARS-CoV-2 can block IRF3 and NF-κB activation early during virus infection. We also identify that the SARS-CoV-2 viral proteins NSP1 and NSP13 can block interferon activation via distinct mechanisms. NSP1 antagonizes interferon signaling by suppressing host mRNA translation, while NSP13 downregulates interferon and NF-κB promoter signaling by limiting TBK1 and IRF3 activation, as phospho-TBK1 and phospho-IRF3 protein levels are reduced with increasing levels of NSP13 protein expression. NSP13 can also reduce NF-κB activation by both limiting NF-κB phosphorylation and nuclear translocation. Last, we also show that NSP13 binds to TBK1 and downregulates IFIT1 protein expression. Collectively, these data illustrate that SARS-CoV-2 bypasses multiple innate immune activation pathways through distinct mechanisms.


Subject(s)
Adaptor Proteins, Signal Transducing/immunology , COVID-19/immunology , Cell Nucleus/immunology , Interferon Regulatory Factor-3/immunology , RNA-Binding Proteins/immunology , SARS-CoV-2/immunology , Signal Transduction/immunology , Viral Nonstructural Proteins/immunology , Active Transport, Cell Nucleus/genetics , Active Transport, Cell Nucleus/immunology , Adaptor Proteins, Signal Transducing/genetics , COVID-19/genetics , Cell Nucleus/genetics , HeLa Cells , Humans , Interferon Regulatory Factor-3/genetics , NF-kappa B/genetics , NF-kappa B/immunology , Phosphorylation/genetics , Phosphorylation/immunology , /immunology , RNA-Binding Proteins/genetics , SARS-CoV-2/genetics , Signal Transduction/genetics , Viral Nonstructural Proteins/genetics
5.
Proc Natl Acad Sci U S A ; 118(26)2021 06 29.
Article in English | MEDLINE | ID: covidwho-1276011

ABSTRACT

Patients with severe COVID-19 infection exhibit a low level of oxygen in affected tissue and blood. To understand the pathophysiology of COVID-19 infection, it is therefore necessary to understand cell function during hypoxia. We investigated aspects of human monocyte activation under hypoxic conditions. HMGB1 is an alarmin released by stressed cells. Under normoxic conditions, HMGB1 activates interferon regulatory factor (IRF)5 and nuclear factor-κB in monocytes, leading to expression of type I interferon (IFN) and inflammatory cytokines including tumor necrosis factor α, and interleukin 1ß, respectively. When hypoxic monocytes are activated by HMGB1, they produce proinflammatory cytokines but fail to produce type I IFN. Hypoxia-inducible factor-1α, induced by hypoxia, functions as a direct transcriptional repressor of IRF5 and IRF3. As hypoxia is a stressor that induces secretion of HMGB1 by epithelial cells, hypoxia establishes a microenvironment that favors monocyte production of inflammatory cytokines but not IFN. These findings have implications for the pathogenesis of COVID-19.


Subject(s)
Cell Hypoxia/immunology , Hypoxia-Inducible Factor 1, alpha Subunit/immunology , Monocytes/immunology , COVID-19/immunology , Cells, Cultured , Cytokines/immunology , Humans , Interferon Regulatory Factors/metabolism , Interferon Type I/immunology , Interferon Type I/metabolism , Interleukin-1beta/metabolism , Monocytes/metabolism , NF-kappa B/immunology , NF-kappa B/metabolism , Oxygen/metabolism , SARS-CoV-2/immunology , Tumor Necrosis Factor-alpha/metabolism
6.
EMBO J ; 40(15): e107826, 2021 08 02.
Article in English | MEDLINE | ID: covidwho-1261483

ABSTRACT

SARS-CoV-2 infection causes broad-spectrum immunopathological disease, exacerbated by inflammatory co-morbidities. A better understanding of mechanisms underpinning virus-associated inflammation is required to develop effective therapeutics. Here, we discover that SARS-CoV-2 replicates rapidly in lung epithelial cells despite triggering a robust innate immune response through the activation of cytoplasmic RNA sensors RIG-I and MDA5. The inflammatory mediators produced during epithelial cell infection can stimulate primary human macrophages to enhance cytokine production and drive cellular activation. Critically, this can be limited by abrogating RNA sensing or by inhibiting downstream signalling pathways. SARS-CoV-2 further exacerbates the local inflammatory environment when macrophages or epithelial cells are primed with exogenous inflammatory stimuli. We propose that RNA sensing of SARS-CoV-2 in lung epithelium is a key driver of inflammation, the extent of which is influenced by the inflammatory state of the local environment, and that specific inhibition of innate immune pathways may beneficially mitigate inflammation-associated COVID-19.


Subject(s)
COVID-19/immunology , DEAD Box Protein 58/immunology , Epithelial Cells/immunology , Interferon-Induced Helicase, IFIH1/immunology , Macrophages/immunology , RNA, Viral/immunology , Receptors, Immunologic/immunology , SARS-CoV-2 , COVID-19/genetics , COVID-19/virology , Cell Line , Cytokines/genetics , Cytokines/immunology , Epithelial Cells/virology , Host-Pathogen Interactions , Humans , Immunity, Innate , Inflammation/genetics , Inflammation/immunology , Inflammation/virology , Janus Kinases/immunology , Lung/cytology , Lung/immunology , Lung/virology , Macrophage Activation , NF-kappa B/immunology , Respiratory Mucosa/cytology , Respiratory Mucosa/immunology , Respiratory Mucosa/virology , SARS-CoV-2/genetics , SARS-CoV-2/physiology , STAT Transcription Factors/immunology , Virus Replication
7.
J Biol Chem ; 296: 100687, 2021.
Article in English | MEDLINE | ID: covidwho-1198855

ABSTRACT

Glucocorticoids are potent anti-inflammatory drugs that are used to treat an extraordinary range of human disease, including COVID-19, underscoring the ongoing importance of understanding their molecular mechanisms. Early studies of GR signaling led to broad acceptance of models in which glucocorticoid receptor (GR) monomers tether repressively to inflammatory transcription factors, thus abrogating inflammatory gene expression. However, newer data challenge this core concept and present an exciting opportunity to reframe our understanding of GR signaling. Here, we present an alternate, two-part model for transcriptional repression by glucocorticoids. First, widespread GR-mediated induction of transcription results in rapid, primary repression of inflammatory gene transcription and associated enhancers through competition-based mechanisms. Second, a subset of GR-induced genes, including targets that are regulated in coordination with inflammatory transcription factors such as NF-κB, exerts secondary repressive effects on inflammatory gene expression. Within this framework, emerging data indicate that the gene set regulated through the cooperative convergence of GR and NF-κB signaling is central to the broad clinical effectiveness of glucocorticoids in terminating inflammation and promoting tissue repair.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , COVID-19/drug therapy , Dexamethasone/therapeutic use , Glucocorticoids/therapeutic use , NF-kappa B/genetics , Receptors, Glucocorticoid/genetics , Animals , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Gene Expression Regulation , Genomics/methods , Humans , Inflammation/prevention & control , Models, Genetic , NF-kappa B/antagonists & inhibitors , NF-kappa B/immunology , Receptors, Glucocorticoid/agonists , Receptors, Glucocorticoid/immunology , SARS-CoV-2/growth & development , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Signal Transduction , Transcription, Genetic/drug effects , Transcription, Genetic/immunology
8.
Scand J Immunol ; 94(4): e13044, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1192682

ABSTRACT

Coronaviruses (CoVs) are a large family of respiratory viruses which can cause mild to moderate upper respiratory tract infections. Recently, new coronavirus named as Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been identified which is a major threat to public health. Innate immune responses play a vital role in a host's defence against viruses. Interestingly, CoVs have evolved elaborate strategies to evade the complex system of sensors and signalling molecules to suppress host immunity. SARS-CoV-2 papain-like protease (PLpro), as an important coronavirus enzyme, regulates viral spread and innate immune responses. SCoV-2 PLpro is multifunctional enzyme with deubiquitinating (DUB) and deISGylating activity. The PLpro can interact with key regulators in signalling pathways such as STING, NF-κB, cytokine production, MAPK and TGF-ß and hijack those to block the immune responses. Therefore, the PLpro can be as an important target for the treatment of COVID-19. Until now, several drugs or compounds have been identified that can inhibit PLpro activity. Here we discuss about the dysregulation effects of PLpro on immune system and drugs that have potential inhibitors for SCoV-2 PLpro.


Subject(s)
COVID-19/immunology , Coronavirus Papain-Like Proteases/immunology , Immune System/immunology , SARS-CoV-2/immunology , Viral Proteins/immunology , Antiviral Agents/administration & dosage , Antiviral Agents/immunology , COVID-19/drug therapy , COVID-19/virology , Coronavirus Papain-Like Proteases/metabolism , Cytokines/immunology , Cytokines/metabolism , Humans , Immune System/metabolism , NF-kappa B/immunology , NF-kappa B/metabolism , Protein Binding/drug effects , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Viral Proteins/metabolism
9.
Front Immunol ; 12: 653344, 2021.
Article in English | MEDLINE | ID: covidwho-1191684

ABSTRACT

Sepsis is a heterogeneous syndrome caused by a dysregulated host response during the process of infection. Neutrophils are involved in the development of sepsis due to their essential role in host defense. COVID-19 is a viral sepsis. Disfunction of neutrophils in sepsis has been described in previous studies, however, little is known about the role of microRNA-let-7b (miR-let-7b), toll-like receptor 4 (TLR4), and nuclear factor kappa B (NF-κB) activity in neutrophils and how they participate in the development of sepsis. In this study, we investigated the regulatory pathway of miR-let-7b/TLR4/NF-κB in neutrophils. We also explored the downstream cytokines released by neutrophils following miR-let-7b treatment and its therapeutic effects in cecal ligation and puncture (CLP)-induced septic mice. Six-to-eight-week-old male C57BL/6 mice underwent CLP following treatment with miR-let-7b agomir. Survival (n=10), changes in liver and lungs histopathology (n=4), circulating neutrophil counts (n=4), the liver-body weight ratio (n=4-7), and the lung wet-to-dry ratio (n=5-6) were recorded. We found that overexpression of miR-let-7b could significantly down-regulate the expression of human-derived neutrophilic TLR4 at a post-transcriptional level, a decreased level of proinflammatory factors including interleukin-6 (IL-6), IL-8, tumor necrosis factor α (TNF-α), and an upregulation of anti-inflammatory factor IL-10 in vitro. After miR-let-7b agomir treatment in vivo, neutrophil recruitment was inhibited and thus the injuries of liver and lungs in CLP-induced septic mice were alleviated (p=0.01 and p=0.04, respectively), less weight loss was reduced, and survival in septic mice was also significantly improved (p=0.013). Our study suggested that miR-let-7b could be a potential target of sepsis.


Subject(s)
COVID-19/immunology , MicroRNAs/immunology , NF-kappa B/immunology , Neutrophils/immunology , SARS-CoV-2/immunology , Signal Transduction/immunology , Toll-Like Receptor 4/immunology , COVID-19/pathology , Humans , Inflammation/immunology , Inflammation/pathology , Neutrophils/pathology
10.
Viruses ; 13(3)2021 02 27.
Article in English | MEDLINE | ID: covidwho-1190473

ABSTRACT

The immunological findings from autopsies, biopsies, and various studies in COVID-19 patients show that the major cause of morbidity and mortality in COVID-19 is excess immune response resulting in hyper-inflammation. With the objective to review various mechanisms of excess immune response in adult COVID-19 patients, Pubmed was searched for free full articles not related to therapeutics or co-morbid sub-groups, published in English until 27.10.2020, irrespective of type of article, country, or region. Joanna Briggs Institute's design-specific checklists were used to assess the risk of bias. Out of 122 records screened for eligibility, 42 articles were included in the final review. The review found that eventually, most mechanisms result in cytokine excess and up-regulation of Nuclear Factor-κB (NF-κB) signaling as a common pathway of excess immune response. Molecules blocking NF-κB or targeting downstream effectors like Tumour Necrosis Factor α (TNFα) are either undergoing clinical trials or lack specificity and cause unwanted side effects. Neutralization of upstream histamine by histamine-conjugated normal human immunoglobulin has been demonstrated to inhibit the nuclear translocation of NF-κB, thereby preventing the release of pro-inflammatory cytokines Interleukin (IL) 1ß, TNF-α, and IL-6 and IL-10 in a safer manner. The authors recommend repositioning it in COVID-19.


Subject(s)
COVID-19/immunology , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/immunology , Histamine/administration & dosage , Immunoglobulins/administration & dosage , NF-kappa B/antagonists & inhibitors , NF-kappa B/immunology , Cytokine Release Syndrome/prevention & control , Cytokine Release Syndrome/virology , Databases, Factual , Down-Regulation/drug effects , Drug Repositioning , Humans , Immunity , Orphan Drug Production , SARS-CoV-2/drug effects , Signal Transduction/drug effects
11.
Mol Ther ; 29(3): 1174-1185, 2021 03 03.
Article in English | MEDLINE | ID: covidwho-985497

ABSTRACT

Self-amplifying RNA (saRNA) is a cutting-edge platform for both nucleic acid vaccines and therapeutics. saRNA is self-adjuvanting, as it activates types I and III interferon (IFN), which enhances the immunogenicity of RNA vaccines but can also lead to inhibition of translation. In this study, we screened a library of saRNA constructs with cis-encoded innate inhibiting proteins (IIPs) and determined the effect on protein expression and immunogenicity. We observed that the PIV-5 V and Middle East respiratory syndrome coronavirus (MERS-CoV) ORF4a proteins enhance protein expression 100- to 500-fold in vitro in IFN-competent HeLa and MRC5 cells. We found that the MERS-CoV ORF4a protein partially abates dose nonlinearity in vivo, and that ruxolitinib, a potent Janus kinase (JAK)/signal transducer and activator of transcription (STAT) inhibitor, but not the IIPs, enhances protein expression of saRNA in vivo. Both the PIV-5 V and MERS-CoV ORF4a proteins were found to enhance the percentage of resident cells in human skin explants expressing saRNA and completely rescued dose nonlinearity of saRNA. Finally, we observed that the MERS-CoV ORF4a increased the rabies virus (RABV)-specific immunoglobulin G (IgG) titer and neutralization half-maximal inhibitory concentration (IC50) by ∼10-fold in rabbits, but not in mice or rats. These experiments provide a proof of concept that IIPs can be directly encoded into saRNA vectors and effectively abate the nonlinear dose dependency and enhance immunogenicity.


Subject(s)
Immunity, Innate/drug effects , Immunogenicity, Vaccine , Protein Biosynthesis/drug effects , Vaccines, Synthetic/pharmacology , Viral Envelope Proteins/administration & dosage , Animals , Cell Line , Encephalitis Virus, Venezuelan Equine/drug effects , Encephalitis Virus, Venezuelan Equine/immunology , Encephalitis Virus, Venezuelan Equine/pathogenicity , Fibroblasts , Gene Expression Regulation , HeLa Cells , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , Immunoglobulin G/biosynthesis , Interferon Regulatory Factor-3/genetics , Interferon Regulatory Factor-3/immunology , Janus Kinases/antagonists & inhibitors , Janus Kinases/genetics , Janus Kinases/immunology , Mice , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/immunology , Middle East Respiratory Syndrome Coronavirus/pathogenicity , NF-kappa B/genetics , NF-kappa B/immunology , Nitriles , Parainfluenza Virus 5/drug effects , Parainfluenza Virus 5/immunology , Parainfluenza Virus 5/pathogenicity , Pyrazoles/pharmacology , Pyrimidines , Rabbits , Rabies virus/drug effects , Rabies virus/immunology , Rabies virus/pathogenicity , Rats , STAT Transcription Factors/antagonists & inhibitors , STAT Transcription Factors/genetics , STAT Transcription Factors/immunology , Signal Transduction , Vaccines, Synthetic/biosynthesis , Viral Envelope Proteins/genetics , Viral Envelope Proteins/immunology
12.
Viruses ; 13(3)2021 02 27.
Article in English | MEDLINE | ID: covidwho-1125711

ABSTRACT

The immunological findings from autopsies, biopsies, and various studies in COVID-19 patients show that the major cause of morbidity and mortality in COVID-19 is excess immune response resulting in hyper-inflammation. With the objective to review various mechanisms of excess immune response in adult COVID-19 patients, Pubmed was searched for free full articles not related to therapeutics or co-morbid sub-groups, published in English until 27.10.2020, irrespective of type of article, country, or region. Joanna Briggs Institute's design-specific checklists were used to assess the risk of bias. Out of 122 records screened for eligibility, 42 articles were included in the final review. The review found that eventually, most mechanisms result in cytokine excess and up-regulation of Nuclear Factor-κB (NF-κB) signaling as a common pathway of excess immune response. Molecules blocking NF-κB or targeting downstream effectors like Tumour Necrosis Factor α (TNFα) are either undergoing clinical trials or lack specificity and cause unwanted side effects. Neutralization of upstream histamine by histamine-conjugated normal human immunoglobulin has been demonstrated to inhibit the nuclear translocation of NF-κB, thereby preventing the release of pro-inflammatory cytokines Interleukin (IL) 1ß, TNF-α, and IL-6 and IL-10 in a safer manner. The authors recommend repositioning it in COVID-19.


Subject(s)
COVID-19/immunology , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/immunology , Histamine/administration & dosage , Immunoglobulins/administration & dosage , NF-kappa B/antagonists & inhibitors , NF-kappa B/immunology , Cytokine Release Syndrome/prevention & control , Cytokine Release Syndrome/virology , Databases, Factual , Down-Regulation/drug effects , Drug Repositioning , Humans , Immunity , Orphan Drug Production , SARS-CoV-2/drug effects , Signal Transduction/drug effects
13.
Viruses ; 13(3)2021 02 27.
Article in English | MEDLINE | ID: covidwho-1120708

ABSTRACT

The immunological findings from autopsies, biopsies, and various studies in COVID-19 patients show that the major cause of morbidity and mortality in COVID-19 is excess immune response resulting in hyper-inflammation. With the objective to review various mechanisms of excess immune response in adult COVID-19 patients, Pubmed was searched for free full articles not related to therapeutics or co-morbid sub-groups, published in English until 27.10.2020, irrespective of type of article, country, or region. Joanna Briggs Institute's design-specific checklists were used to assess the risk of bias. Out of 122 records screened for eligibility, 42 articles were included in the final review. The review found that eventually, most mechanisms result in cytokine excess and up-regulation of Nuclear Factor-κB (NF-κB) signaling as a common pathway of excess immune response. Molecules blocking NF-κB or targeting downstream effectors like Tumour Necrosis Factor α (TNFα) are either undergoing clinical trials or lack specificity and cause unwanted side effects. Neutralization of upstream histamine by histamine-conjugated normal human immunoglobulin has been demonstrated to inhibit the nuclear translocation of NF-κB, thereby preventing the release of pro-inflammatory cytokines Interleukin (IL) 1ß, TNF-α, and IL-6 and IL-10 in a safer manner. The authors recommend repositioning it in COVID-19.


Subject(s)
COVID-19/immunology , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/immunology , Histamine/administration & dosage , Immunoglobulins/administration & dosage , NF-kappa B/antagonists & inhibitors , NF-kappa B/immunology , Cytokine Release Syndrome/prevention & control , Cytokine Release Syndrome/virology , Databases, Factual , Down-Regulation/drug effects , Drug Repositioning , Humans , Immunity , Orphan Drug Production , SARS-CoV-2/drug effects , Signal Transduction/drug effects
14.
Virus Res ; 299: 198347, 2021 07 02.
Article in English | MEDLINE | ID: covidwho-1096265

ABSTRACT

BACKGROUND: There is a marked discrepancy between SARS-CoV-2 seroprevalence and COVID-19 cases and deaths in Africa. MAIN: SARS-CoV-2 stimulates humoral and cellular immunity systems, as well as mitogen-activated protein kinase (MAPK) and nuclear NF-kB signalling pathways, which regulate inflammatory gene expression and immune cell differentiation. The result is pro-inflammatory cytokines release, hyperinflammatory condition, and cytokine storm, which provoke severe lung alterations that can lead to multi-organ failure in COVID-19. Multiple genetic and immunologic factors may contribute to the severity of COVID-19 in African individuals when compared to the rest of the global population. In this article, the role of malaria, NF-kB and MAPK pathways, caspase-12 expression, high level of LAIR-1-containing antibodies, and differential glycophorins (GYPA/B) expression in COVID-19 are discussed. CONCLUSION: Understanding pathophysiological mechanisms can help identify target points for drugs and vaccines development against COVID-19. To our knowledge, this is the first study that explores this link and proposes a biological and molecular answer to the epidemiologic discrepancy in COVID-19 in Africa.


Subject(s)
COVID-19/genetics , COVID-19/immunology , Malaria/genetics , Malaria/immunology , Africa/epidemiology , COVID-19/epidemiology , COVID-19/ethnology , Caspase 12/genetics , Caspase 12/immunology , Glycophorins/genetics , Glycophorins/immunology , Humans , Malaria/epidemiology , Malaria/ethnology , NF-kappa B/immunology , Receptors, Immunologic/genetics , Receptors, Immunologic/immunology , SARS-CoV-2/immunology , Signal Transduction/immunology
15.
Med Hypotheses ; 146: 110412, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-1065477

ABSTRACT

The Corona Virus Disease (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) requires a rapid solution and global collaborative efforts in order to define preventive and treatment strategies. One of the major challenges of this disease is the high number of patients needing advanced respiratory support due to the Acute Respiratory Distress Syndrome (ARDS) as the lung is the major - although not exclusive - target of the virus. The molecular mechanisms, pathogenic drivers and the target cell type(s) in SARS-CoV-2 infection are still poorly understood, but the development of a "hyperactive" immune response is proposed to play a role in the evolution of the disease and it is envisioned as a major cause of morbidity and mortality. Here we propose a theory by which the main targets for SARS-CoV-2 are the Type II Alveolar Epithelial Cells and the clinical manifestations of the syndrome are a direct consequence of their involvement. We propose the existence of a vicious cycle by which once alveolar damage starts in AEC II cells, the inflammatory state is supported by macrophage pro-inflammatory polarization (M1), cytokines release and by the activation of the NF-κB pathway. If this theory is confirmed, future therapeutic efforts can be directed to target Type 2 alveolar cells and the molecular pathogenic drivers associated with their dysfunction with currently available therapeutic strategies.


Subject(s)
Alveolar Epithelial Cells/immunology , Alveolar Epithelial Cells/virology , COVID-19/immunology , COVID-19/virology , Models, Biological , NF-kappa B/immunology , SARS-CoV-2 , Alveolar Epithelial Cells/pathology , Angiotensin-Converting Enzyme 2/physiology , COVID-19/etiology , Endothelium, Vascular/immunology , Endothelium, Vascular/pathology , Heparin, Low-Molecular-Weight/therapeutic use , Humans , Inflammation/immunology , Inflammation/pathology , Liquid Ventilation , Macrophages/immunology , Macrophages/pathology , NF-kappa B/antagonists & inhibitors , Neutrophils/immunology , Neutrophils/pathology , Pandemics , Pulmonary Surfactants/therapeutic use , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/immunology , Respiratory Distress Syndrome/virology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Signal Transduction/immunology
16.
Sci Immunol ; 6(55)2021 01 21.
Article in English | MEDLINE | ID: covidwho-1042797

ABSTRACT

The molecular properties of CD8+ T cells that respond to SARS-CoV-2 infection are not fully known. Here, we report on the single-cell transcriptomes of >80,000 virus-reactive CD8+ T cells, obtained using a modified Antigen-Reactive T cell Enrichment (ARTE) assay, from 39 COVID-19 patients and 10 healthy subjects. COVID-19 patients segregated into two groups based on whether the dominant CD8+ T cell response to SARS-CoV-2 was 'exhausted' or not. SARS-CoV-2-reactive cells in the exhausted subset were increased in frequency and displayed lesser cytotoxicity and inflammatory features in COVID-19 patients with mild compared to severe illness. In contrast, SARS-CoV-2-reactive cells in the dominant non-exhausted subset from patients with severe disease showed enrichment of transcripts linked to co-stimulation, pro-survival NF-κB signaling, and anti-apoptotic pathways, suggesting the generation of robust CD8+ T cell memory responses in patients with severe COVID-19 illness. CD8+ T cells reactive to influenza and respiratory syncytial virus from healthy subjects displayed polyfunctional features and enhanced glycolysis. Cells with such features were largely absent in SARS-CoV-2-reactive cells from both COVID-19 patients and healthy controls non-exposed to SARS-CoV-2. Overall, our single-cell analysis revealed substantial diversity in the nature of CD8+ T cells responding to SARS-CoV-2.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Female , Glycolysis/immunology , Humans , Immunologic Memory/immunology , Male , Middle Aged , NF-kappa B/immunology , Signal Transduction/immunology , Single-Cell Analysis/methods , Young Adult
17.
JCI Insight ; 6(1)2021 01 11.
Article in English | MEDLINE | ID: covidwho-1027164

ABSTRACT

Immune and inflammatory responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contribute to disease severity of coronavirus disease 2019 (COVID-19). However, the utility of specific immune-based biomarkers to predict clinical outcome remains elusive. Here, we analyzed levels of 66 soluble biomarkers in 175 Italian patients with COVID-19 ranging from mild/moderate to critical severity and assessed type I IFN-, type II IFN-, and NF-κB-dependent whole-blood transcriptional signatures. A broad inflammatory signature was observed, implicating activation of various immune and nonhematopoietic cell subsets. Discordance between IFN-α2a protein and IFNA2 transcript levels in blood suggests that type I IFNs during COVID-19 may be primarily produced by tissue-resident cells. Multivariable analysis of patients' first samples revealed 12 biomarkers (CCL2, IL-15, soluble ST2 [sST2], NGAL, sTNFRSF1A, ferritin, IL-6, S100A9, MMP-9, IL-2, sVEGFR1, IL-10) that when increased were independently associated with mortality. Multivariate analyses of longitudinal biomarker trajectories identified 8 of the aforementioned biomarkers (IL-15, IL-2, NGAL, CCL2, MMP-9, sTNFRSF1A, sST2, IL-10) and 2 additional biomarkers (lactoferrin, CXCL9) that were substantially associated with mortality when increased, while IL-1α was associated with mortality when decreased. Among these, sST2, sTNFRSF1A, IL-10, and IL-15 were consistently higher throughout the hospitalization in patients who died versus those who recovered, suggesting that these biomarkers may provide an early warning of eventual disease outcome.


Subject(s)
COVID-19/immunology , COVID-19/mortality , Adrenal Cortex Hormones/therapeutic use , Adult , Aged , Anti-Bacterial Agents/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Antiviral Agents/therapeutic use , Azithromycin/therapeutic use , Biomarkers , COVID-19/genetics , COVID-19/therapy , Calgranulin B/genetics , Calgranulin B/immunology , Case-Control Studies , Chemokine CCL2/genetics , Chemokine CCL2/immunology , Chemokine CXCL9/genetics , Chemokine CXCL9/immunology , Enzyme Inhibitors/therapeutic use , Female , Ferritins/genetics , Ferritins/immunology , Gene Expression Profiling , Humans , Hydroxychloroquine/therapeutic use , Immunologic Factors/therapeutic use , Interferon Type I/genetics , Interferon Type I/immunology , Interferon-gamma/genetics , Interferon-gamma/immunology , Interleukin-1 Receptor-Like 1 Protein/genetics , Interleukin-1 Receptor-Like 1 Protein/immunology , Interleukin-10/genetics , Interleukin-10/immunology , Interleukin-15/genetics , Interleukin-15/immunology , Interleukin-2/genetics , Interleukin-2/immunology , Interleukin-6/genetics , Interleukin-6/immunology , Lactoferrin/genetics , Lactoferrin/immunology , Lipocalin-2/genetics , Lipocalin-2/immunology , Male , Matrix Metalloproteinase 9/genetics , Matrix Metalloproteinase 9/immunology , Middle Aged , Multivariate Analysis , NF-kappa B/genetics , NF-kappa B/immunology
18.
Inflammopharmacology ; 29(1): 91-100, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-911912

ABSTRACT

Coronavirus disease 2019 (COVID-19) pandemic has affected health care systems worldwide. Severe presentations of COVID-19 such as severe pneumonia and acute respiratory distress syndrome (ARDS) have been associated with the post-viral activation and release of cytokine/chemokines which leads to a "cytokine storm" causing inflammatory response and destruction, mainly affecting the lungs. COVID-19 activation of transcription factor, NF-kappa B (NF-κB) in various cells such as macrophages of lung, liver, kidney, central nervous system, gastrointestinal system and cardiovascular system leads to production of IL-1, IL-2, IL-6, IL-12, TNF-α, LT-α, LT-ß, GM-CSF, and various chemokines. The sensitised NF-κB in elderly and in patients with metabolic syndrome makes this set of population susceptible to COVID-19 and their worse complications, including higher mortality. Immunomodulation at the level of NF-κB activation and inhibitors of NF-κB (IκB) degradation along with TNF-α inhibition will potentially result in a reduction in the cytokine storm and alleviate the severity of COVID-19. Inhibition of NF-κB pathway has a potential therapeutic role in alleviating the severe form of COVID-19.


Subject(s)
COVID-19/drug therapy , Cytokine Release Syndrome/prevention & control , Glucocorticoids/therapeutic use , NF-kappa B/antagonists & inhibitors , Respiratory Distress Syndrome/drug therapy , SARS-CoV-2 , Aging/immunology , COVID-19/complications , COVID-19/immunology , Humans , Metabolic Syndrome/immunology , NF-kappa B/immunology , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/immunology , Severity of Illness Index , Sex Characteristics , Signal Transduction
19.
Viruses ; 12(1)2020 01 09.
Article in English | MEDLINE | ID: covidwho-830212

ABSTRACT

Porcine deltacoronavirus (PDCoV) is a porcine enteropathogenic coronavirus that causes watery diarrhea, vomiting, and frequently death in piglets, causing serious economic losses to the pig industry. The strain CHN-JS-2017 was isolated and identified by cytopathology, immunofluorescence assays, transmission electron microscopy, and sequence analysis. A nucleotide sequence alignment showed that the whole genome of CHN-JS-2017 is 97.4%-99.6% identical to other PDCoV strains. The pathogenicity of the CHN-JS-2017 strain was investigated in orally inoculated five-day-old piglets; the piglets developed acute, watery diarrhea, but all recovered and survived. CHN-JS-2017 infection-induced microscopic lesions were observed, and viral antigens were detected mainly by immunohistochemical staining in the small intestine. The neonatal Fc receptor (FcRn) and polymeric immunoglobulin receptor (pIgR) are crucial immunoglobulin (Ig) receptors for the transcytosis ofimmunoglobulin G (IgG), IgA, or IgM. Importantly, CHN-JS-2017 infected five-day-old piglets could significantly down-regulate the expression of FcRn, pIgR, and nuclear factor-kappa B (NF-κB)in the intestinal mucosa. Note that the level of FcRn mRNA in the intestinal mucosa of normal piglets is positively correlated with pIgR and NF-κB. At the same time, the expressions of FcRn, pIgR, and NF-κB mRNA are also positively correlated in infected piglets. These results may help explain the immunological and pathological changes associated with porcine deltacorononirus infection.


Subject(s)
Coronavirus Infections/veterinary , Coronavirus/classification , Histocompatibility Antigens Class I/immunology , Intestinal Mucosa/immunology , Receptors, Fc/immunology , Receptors, Polymeric Immunoglobulin/immunology , Swine Diseases/virology , Animals , Antigens, Viral/analysis , Coronavirus/isolation & purification , Coronavirus Infections/immunology , Diarrhea/veterinary , Diarrhea/virology , Gene Expression Regulation , Intestinal Mucosa/virology , Intestine, Small/immunology , Intestine, Small/virology , NF-kappa B/immunology , Phylogeny , RNA, Viral/analysis , Sequence Alignment , Sequence Analysis, DNA , Swine , Swine Diseases/immunology , Virus Shedding
20.
Vet Microbiol ; 247: 108785, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-827867

ABSTRACT

Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes watery diarrhea, vomiting and mortality in nursing piglets. Type III interferons (IFN-λs) are the major antiviral cytokines in intestinal epithelial cells, the target cells in vivo for PDCoV. In this study, we found that PDCoV infection remarkably inhibited Sendai virus-induced IFN-λ1 production by suppressing transcription factors IRF and NF-κB in IPI-2I cells, a line of porcine intestinal mucosal epithelial cells. We also confirmed that PDCoV infection impeded the activation of IFN-λ1 promoter stimulated by RIG-I, MDA5 and MAVS, but not by TBK1 and IRF1. Although the expression levels of IRF1 and MAVS were not changed, PDCoV infection resulted in reduction of the number of peroxisomes, the platform for MAVS to activate IRF1, and subsequent type III IFN production. Taken together, our study demonstrates that PDCoV suppresses type III IFN responses to circumvent the host's antiviral immunity.


Subject(s)
Coronavirus Infections/veterinary , Epithelial Cells/immunology , Epithelial Cells/virology , Host-Pathogen Interactions/immunology , Interferons/antagonists & inhibitors , Animals , Cell Line , Coronavirus , Coronavirus Infections/immunology , Coronavirus Infections/virology , Interferon Regulatory Factor-1/antagonists & inhibitors , Interferon Regulatory Factor-1/immunology , Interferons/immunology , Intestines/cytology , Intestines/virology , Kidney/cytology , Kidney/virology , NF-kappa B/antagonists & inhibitors , NF-kappa B/immunology , Sendai virus/immunology , Signal Transduction/immunology , Swine/virology , Swine Diseases/immunology , Swine Diseases/virology
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