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1.
Front Immunol ; 12: 700705, 2021.
Article in English | MEDLINE | ID: covidwho-1686468

ABSTRACT

A novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), arose late in 2019, with disease pathology ranging from asymptomatic to severe respiratory distress with multi-organ failure requiring mechanical ventilator support. It has been found that SARS-CoV-2 infection drives intracellular complement activation in lung cells that tracks with disease severity. However, the cellular and molecular mechanisms responsible remain unclear. To shed light on the potential mechanisms, we examined publicly available RNA-Sequencing data using CIBERSORTx and conducted a Ingenuity Pathway Analysis to address this knowledge gap. In complement to these findings, we used bioinformatics tools to analyze publicly available RNA sequencing data and found that upregulation of complement may be leading to a downregulation of T-cell activity in lungs of severe COVID-19 patients. Thus, targeting treatments aimed at the modulation of classical complement and T-cell activity may help alleviate the proinflammatory effects of COVID-19, reduce lung pathology, and increase the survival of COVID-19 patients.


Subject(s)
COVID-19/genetics , Complement Activation/genetics , Complement System Proteins/genetics , Gene Expression Profiling/methods , Lung/metabolism , T-Lymphocytes/metabolism , COVID-19/immunology , COVID-19/virology , Gene Regulatory Networks/genetics , Humans , Intracellular Space/genetics , Lung/immunology , Lung/microbiology , Lymphocyte Count , SARS-CoV-2/physiology , T-Lymphocyte Subsets/metabolism
2.
J Clin Immunol ; 42(3): 665-671, 2022 04.
Article in English | MEDLINE | ID: covidwho-1653614

ABSTRACT

BACKGROUND: Terminal complement pathway deficiencies often present with severe and recurrent infections. There is a lack of good-quality data on these rare conditions. This study investigated the clinical outcome and genetic variation in a large UK multi-center cohort with primary and secondary terminal complement deficiencies. METHODS: Clinicians from seven UK centers provided anonymised demographic, clinical, and laboratory data on patients with terminal complement deficiencies, which were collated and analysed. RESULTS: Forty patients, median age 19 (range 3-62) years, were identified with terminal complement deficiencies. Ten (62%) of 16 patients with low serum C5 concentrations had underlying pathogenic CFH or CFI gene variants. Two-thirds were from consanguineous Asian families, and 80% had an affected family member. The median age of the first infection was 9 years. Forty-three percent suffered meningococcal serotype B and 43% serotype Y infections. Nine (22%) were treated in intensive care for meningococcal septicaemia. Two patients had died, one from intercurrent COVID-19. Twenty-one (52%) were asymptomatic and diagnosed based on family history. All but one patient had received booster meningococcal vaccines and 70% were taking prophylactic antibiotics. DISCUSSION: The genetic etiology and clinical course of patients with primary and secondary terminal complement deficiency are variable. Patients with low antigenic C5 concentrations require genetic testing, as the low level may reflect consumption secondary to regulatory defects in the pathway. Screening of siblings is important. Only half of the patients develop septicaemia, but all should have a clear management plan.


Subject(s)
COVID-19 , Meningococcal Infections , Sepsis , Adolescent , Adult , Child , Child, Preschool , Cohort Studies , Complement System Proteins/genetics , Hereditary Complement Deficiency Diseases , Humans , Meningococcal Infections/genetics , Middle Aged , United Kingdom/epidemiology , Young Adult
3.
J Cell Mol Med ; 26(5): 1445-1455, 2022 03.
Article in English | MEDLINE | ID: covidwho-1642687

ABSTRACT

There is an unmet need of models for early prediction of morbidity and mortality of Coronavirus disease-19 (COVID-19). We aimed to a) identify complement-related genetic variants associated with the clinical outcomes of ICU hospitalization and death, b) develop an artificial neural network (ANN) predicting these outcomes and c) validate whether complement-related variants are associated with an impaired complement phenotype. We prospectively recruited consecutive adult patients of Caucasian origin, hospitalized due to COVID-19. Through targeted next-generation sequencing, we identified variants in complement factor H/CFH, CFB, CFH-related, CFD, CD55, C3, C5, CFI, CD46, thrombomodulin/THBD, and A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS13). Among 381 variants in 133 patients, we identified 5 critical variants associated with severe COVID-19: rs2547438 (C3), rs2250656 (C3), rs1042580 (THBD), rs800292 (CFH) and rs414628 (CFHR1). Using age, gender and presence or absence of each variant, we developed an ANN predicting morbidity and mortality in 89.47% of the examined population. Furthermore, THBD and C3a levels were significantly increased in severe COVID-19 patients and those harbouring relevant variants. Thus, we reveal for the first time an ANN accurately predicting ICU hospitalization and death in COVID-19 patients, based on genetic variants in complement genes, age and gender. Importantly, we confirm that genetic dysregulation is associated with impaired complement phenotype.


Subject(s)
COVID-19/genetics , COVID-19/mortality , Neural Networks, Computer , COVID-19/epidemiology , Complement Activation/genetics , Complement Factor H/genetics , Complement System Proteins/genetics , Female , Greece/epidemiology , Hospitalization/statistics & numerical data , Humans , Intensive Care Units/statistics & numerical data , Male , Middle Aged , Models, Genetic , Morbidity , Polymorphism, Single Nucleotide , Thrombomodulin/genetics
4.
Rev Med Virol ; 31(6): e2221, 2021 11.
Article in English | MEDLINE | ID: covidwho-1575100

ABSTRACT

The current pandemic caused by SARS-CoV-2 virus infection is known as Covid-19 (coronavirus disease 2019). This disease can be asymptomatic or can affect multiple organ systems. Damage induced by the virus is related to dysfunctional activity of the immune system, but the activity of molecules such as C-reactive protein (CRP) as a factor capable of inducing an inflammatory status that may be involved in the severe evolution of the disease, has not been extensively evaluated. A systematic review was performed using the NCBI-PubMed database to find articles related to Covid-19 immunity, inflammatory response, and CRP published from December 2019 to December 2020. High levels of CRP were found in patients with severe evolution of Covid-19 in which several organ systems were affected and in patients who died. CRP activates complement, induces the production of pro-inflammatory cytokines and induces apoptosis which, together with the inflammatory status during the disease, can lead to a severe outcome. Several drugs can decrease the level or block the effect of CRP and might be useful in the treatment of Covid-19. From this review it is reasonable to conclude that CRP is a factor that can contribute to severe evolution of Covid-19 and that the use of drugs able to lower CRP levels or block its activity should be evaluated in randomized controlled clinical trials.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , C-Reactive Protein/antagonists & inhibitors , COVID-19/drug therapy , Complement System Proteins/immunology , Cytokine Release Syndrome/drug therapy , SARS-CoV-2/pathogenicity , ADAM17 Protein/antagonists & inhibitors , ADAM17 Protein/genetics , ADAM17 Protein/immunology , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Biomarkers/blood , C-Reactive Protein/genetics , C-Reactive Protein/immunology , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Celecoxib/therapeutic use , Complement System Proteins/genetics , Cytokine Release Syndrome/immunology , Cytokine Release Syndrome/pathology , Cytokine Release Syndrome/virology , Cytokines/antagonists & inhibitors , Cytokines/genetics , Cytokines/immunology , Disease Progression , Doxycycline/therapeutic use , Gene Expression Regulation , Humans , Randomized Controlled Trials as Topic , Severity of Illness Index , Survival Analysis
5.
BMC Genom Data ; 22(1): 49, 2021 11 14.
Article in English | MEDLINE | ID: covidwho-1518254

ABSTRACT

BACKGROUND: There is an urgent need to understand the key events driving pathogenesis of severe COVID-19 disease, so that precise treatment can be instituted. In this respect NETosis is gaining increased attention in the scientific community, as an important pathological process contributing to mortality. We sought to test if indeed there exists robust evidence of NETosis in multiple transcriptomic data sets from human subjects with severe COVID-19 disease. Gene set enrichment analysis was performed to test for up-regulation of gene set functional in NETosis in the blood of patients with COVID-19 illness. RESULTS: Blood gene expression functional in NETosis increased with severity of illness, showed negative correlation with blood oxygen saturation, and was validated in the lung of COVID-19 non-survivors. Temporal expression of IL-6 was compared between severe and moderate illness with COVID-19. Unsupervised clustering was performed to reveal co-expression of IL-6 with complement genes. In severe COVID-19 illness, there is transcriptional evidence of activation of NETosis, complement and coagulation cascade, and negative correlation between NETosis and respiratory function (oxygen saturation). An early spike in IL-6 is observed in severe COVID-19 illness that is correlated with complement activation. CONCLUSIONS: Based on the transcriptional dynamics of IL-6 expression and its downstream effect on complement activation, we constructed a model that links early spike in IL-6 level with persistent and self-perpetuating complement activation, NETosis, immunothrombosis and respiratory dysfunction. Our model supports the early initiation of anti-IL6 therapy in severe COVID-19 disease before the life-threatening complications of the disease can perpetuate themselves autonomously.


Subject(s)
COVID-19/immunology , Extracellular Traps , Interleukin-6 , Thrombosis/virology , Transcriptome , COVID-19/pathology , Complement System Proteins/genetics , Humans , Interleukin-6/genetics , Oxygen
6.
Molecules ; 25(12)2020 Jun 26.
Article in English | MEDLINE | ID: covidwho-1389454

ABSTRACT

Viruses can be spread from one person to another; therefore, they may cause disorders in many people, sometimes leading to epidemics and even pandemics. New, previously unstudied viruses and some specific mutant or recombinant variants of known viruses constantly appear. An example is a variant of coronaviruses (CoV) causing severe acute respiratory syndrome (SARS), named SARS-CoV-2. Some antiviral drugs, such as remdesivir as well as antiretroviral drugs including darunavir, lopinavir, and ritonavir are suggested to be effective in treating disorders caused by SARS-CoV-2. There are data on the utilization of antiretroviral drugs against SARS-CoV-2. Since there are many studies aimed at the identification of the molecular mechanisms of human immunodeficiency virus type 1 (HIV-1) infection and the development of novel therapeutic approaches against HIV-1, we used HIV-1 for our case study to identify possible molecular pathways shared by SARS-CoV-2 and HIV-1. We applied a text and data mining workflow and identified a list of 46 targets, which can be essential for the development of infections caused by SARS-CoV-2 and HIV-1. We show that SARS-CoV-2 and HIV-1 share some molecular pathways involved in inflammation, immune response, cell cycle regulation.


Subject(s)
Coronavirus Infections/epidemiology , Coronavirus Infections/metabolism , Data Mining/methods , HIV Infections/epidemiology , HIV Infections/metabolism , Host-Pathogen Interactions/immunology , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/metabolism , Anti-Inflammatory Agents/therapeutic use , Antigens, Differentiation/genetics , Antigens, Differentiation/immunology , Antiviral Agents/therapeutic use , Betacoronavirus/drug effects , Betacoronavirus/immunology , Betacoronavirus/pathogenicity , COVID-19 , Complement System Proteins/genetics , Complement System Proteins/immunology , Coronavirus Infections/drug therapy , Coronavirus Infections/immunology , Databases, Genetic , Gene Expression Regulation , HIV Infections/drug therapy , HIV Infections/immunology , HIV-1/drug effects , HIV-1/immunology , HIV-1/pathogenicity , Host-Pathogen Interactions/drug effects , Host-Pathogen Interactions/genetics , Humans , Immunity, Innate/drug effects , Immunologic Factors/therapeutic use , Inflammation , Interferons/genetics , Interferons/immunology , Interleukins/genetics , Interleukins/immunology , Metabolic Networks and Pathways/drug effects , Metabolic Networks and Pathways/genetics , Metabolic Networks and Pathways/immunology , Pneumonia, Viral/drug therapy , Pneumonia, Viral/immunology , Repressor Proteins/genetics , Repressor Proteins/immunology , SARS-CoV-2 , Signal Transduction , Toll-Like Receptors/genetics , Toll-Like Receptors/immunology , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/immunology
7.
Viruses ; 13(5)2021 05 02.
Article in English | MEDLINE | ID: covidwho-1251799

ABSTRACT

The complement system represents a crucial part of innate immunity. It contains a diverse range of soluble activators, membrane-bound receptors, and regulators. Its principal function is to eliminate pathogens via activation of three distinct pathways: classical, alternative, and lectin. In the case of viruses, the complement activation results in effector functions such as virion opsonisation by complement components, phagocytosis induction, virolysis by the membrane attack complex, and promotion of immune responses through anaphylatoxins and chemotactic factors. Recent studies have shown that the addition of individual complement components can neutralise viruses without requiring the activation of the complement cascade. While the complement-mediated effector functions can neutralise a diverse range of viruses, numerous viruses have evolved mechanisms to subvert complement recognition/activation by encoding several proteins that inhibit the complement system, contributing to viral survival and pathogenesis. This review focuses on these complement-dependent and -independent interactions of complement components (especially C1q, C4b-binding protein, properdin, factor H, Mannose-binding lectin, and Ficolins) with several viruses and their consequences.


Subject(s)
Complement Activation/immunology , Complement System Proteins/immunology , Immunity, Innate , Receptors, Pattern Recognition/immunology , Viruses/immunology , Complement System Proteins/genetics , Cytokine Release Syndrome , Cytopathogenic Effect, Viral , Humans
8.
Clin Immunol ; 229: 108795, 2021 08.
Article in English | MEDLINE | ID: covidwho-1305213

ABSTRACT

Acute and chronic kidney failure is common in hospitalized patients with COVID-19, yet the mechanism of injury and predisposing factors remain poorly understood. We investigated the role of complement activation by determining the levels of deposited complement components (C1q, C3, FH, C5b-9) and immunoglobulin along with the expression levels of the injury-associated molecules spleen tyrosine kinase (Syk), mucin-1 (MUC1) and calcium/calmodulin-dependent protein kinase IV (CaMK4) in the kidney tissues of people who succumbed to COVID-19. We report increased deposition of C1q, C3, C5b-9, total immunoglobulin, and high expression levels of Syk, MUC1 and CaMK4 in the kidneys of COVID-19 patients. Our study provides strong rationale for the expansion of trials involving the use of inhibitors of these molecules, in particular C1q, C3, Syk, MUC1 and CaMK4 to treat patients with COVID-19.


Subject(s)
COVID-19/metabolism , Complement System Proteins/metabolism , Kidney/metabolism , Mucin-1/metabolism , SARS-CoV-2 , Syk Kinase/metabolism , Aged , Aged, 80 and over , COVID-19/pathology , Calcium-Calmodulin-Dependent Protein Kinase Type 4/genetics , Calcium-Calmodulin-Dependent Protein Kinase Type 4/metabolism , Complement System Proteins/genetics , Fatal Outcome , Female , Gene Expression Regulation , Humans , Male , Middle Aged , Mucin-1/genetics , Syk Kinase/genetics
9.
Front Immunol ; 11: 573583, 2020.
Article in English | MEDLINE | ID: covidwho-1226976

ABSTRACT

Complement, a part of the innate arm of the immune system, is integral to the frontline defense of the host against innumerable pathogens, which includes RNA viruses. Among the major groups of viruses, RNA viruses contribute significantly to the global mortality and morbidity index associated with viral infection. Despite multiple routes of entry adopted by these viruses, facing complement is inevitable. The initial interaction with complement and the nature of this interaction play an important role in determining host resistance versus susceptibility to the viral infection. Many RNA viruses are potent activators of complement, often resulting in virus neutralization. Yet, another facet of virus-induced activation is the exacerbation in pathogenesis contributing to the overall morbidity. The severity in disease and death associated with RNA virus infections shows a tip in the scale favoring viruses. Growing evidence suggest that like their DNA counterparts, RNA viruses have co-evolved to master ingenious strategies to remarkably restrict complement. Modulation of host genes involved in antiviral responses contributed prominently to the adoption of unique strategies to keep complement at bay, which included either down regulation of activation components (C3, C4) or up regulation of complement regulatory proteins. All this hints at a possible "hijacking" of the cross-talk mechanism of the host immune system. Enveloped RNA viruses have a selective advantage of not only modulating the host responses but also recruiting membrane-associated regulators of complement activation (RCAs). This review aims to highlight the significant progress in the understanding of RNA virus-complement interactions.


Subject(s)
Adaptive Immunity , Complement Activation , Complement System Proteins/immunology , Immunity, Innate , RNA Virus Infections/virology , RNA Viruses/pathogenicity , Animals , Complement System Proteins/genetics , Complement System Proteins/metabolism , Evolution, Molecular , Gene Expression Regulation, Viral , Host-Pathogen Interactions , Humans , RNA Virus Infections/genetics , RNA Virus Infections/immunology , RNA Virus Infections/mortality , RNA Viruses/genetics , RNA Viruses/immunology , Severity of Illness Index
11.
Front Immunol ; 11: 585243, 2020.
Article in English | MEDLINE | ID: covidwho-976265

ABSTRACT

Lung diseases are among the leading causes of morbidity and mortality. Complement activation may prevent a variety of respiratory infections, but on the other hand, could exacerbate tissue damage or contribute to adverse side effects. In this review, the associations of factors specific for complement activation via the lectin pathway (LP) with infections of the respiratory system, from birth to adulthood, are discussed. The most extensive data concern mannose-binding lectin (MBL) which together with other collectins (collectin-10, collectin-11) and the ficolins (ficolin-1, ficolin-2, ficolin-3) belong to pattern-recognition molecules (PRM) specific for the LP. Those PRM form complexes with MBL-associated serine proteases (MASP-1, MASP-2, MASP-3) and related non-enzymatic factors (MAp19, MAp44). Beside diseases affecting humanity for centuries like tuberculosis or neonatal pneumonia, some recently published data concerning COVID-19 are summarized.


Subject(s)
COVID-19/immunology , Complement System Proteins/immunology , Mannose-Binding Lectin/immunology , Respiratory System/immunology , SARS-CoV-2/physiology , Animals , COVID-19/genetics , COVID-19/virology , Complement Activation , Complement Pathway, Mannose-Binding Lectin , Complement System Proteins/genetics , Humans , Mannose-Binding Lectin/genetics , Respiratory System/virology , SARS-CoV-2/genetics , SARS-CoV-2/immunology
12.
J Thromb Haemost ; 19(3): 607-616, 2021 03.
Article in English | MEDLINE | ID: covidwho-740256

ABSTRACT

Antiphospholipid syndrome (APS) is an acquired thromboinflammatory disorder characterized by the presence of antiphospholipid antibodies as well as an increased frequency of venous or arterial thrombosis and/or obstetrical morbidity. The spectrum of disease varies from asymptomatic to a severe form characterized by widespread thrombosis and multiorgan failure, termed catastrophic APS (CAPS). CAPS affects only about ∼1% of APS patients, often presents as a thrombotic microangiopathy and has a fulminant course with >40% mortality, despite the best available therapy. Animal models have implicated complement in the pathophysiology of thrombosis in APS, with more recent data from human studies confirming the interaction between the coagulation and complement pathways. Activation of the complement cascade via antiphospholipid antibodies can cause cellular injury and promote coagulation via multiple mechanisms. Finally, analogous to classic complement-mediated diseases such as atypical hemolytic uremic syndrome, a subset of patients with APS may be at increased risk for development of CAPS because of the presence of germline variants in genes crucial for complement regulation. Together, these data make complement inhibition an attractive and potentially lifesaving therapy to mitigate morbidity and mortality in severe thrombotic APS and CAPS.


Subject(s)
Antiphospholipid Syndrome , Animals , Antibodies, Antiphospholipid , Antiphospholipid Syndrome/genetics , Antiphospholipid Syndrome/therapy , Complement Activation , Complement System Proteins/genetics , Humans , Mutation
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