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1.
Front Immunol ; 13: 870283, 2022.
Article in English | MEDLINE | ID: covidwho-1793011

ABSTRACT

Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2. During T-cell activation, the immune system uses different checkpoint pathways to maintain co-inhibitory and co-stimulatory signals. In COVID-19, expression of immune checkpoints (ICs) is one of the most important manifestations, in addition to lymphopenia and inflammatory cytokines, contributing to worse clinical outcomes. There is a controversy whether upregulation of ICs in COVID-19 patients might lead to T-cell exhaustion or activation. This review summarizes the available studies that investigated IC receptors and ligands in COVID-19 patients, as well as their effect on T-cell function. Several IC receptors and ligands, including CTLA-4, BTLA, TIM-3, VISTA, LAG-3, TIGIT, PD-1, CD160, 2B4, NKG2A, Galectin-9, Galectin-3, PD-L1, PD-L2, LSECtin, and CD112, were upregulated in COVID-19 patients. Based on the available studies, there is a possible relationship between disease severity and increased expression of IC receptors and ligands. Overall, the upregulation of some ICs could be used as a prognostic biomarker for disease severity.


Subject(s)
COVID-19 , Humans , Ligands , Prognosis , Receptors, Immunologic/metabolism , SARS-CoV-2
2.
Nat Immunol ; 23(4): 632-642, 2022 04.
Article in English | MEDLINE | ID: covidwho-1751737

ABSTRACT

Although inhibition of T cell coinhibitory receptors has revolutionized cancer therapy, the mechanisms governing their expression on human T cells have not been elucidated. In the present study, we show that type 1 interferon (IFN-I) regulates coinhibitory receptor expression on human T cells, inducing PD-1/TIM-3/LAG-3 while inhibiting TIGIT expression. High-temporal-resolution mRNA profiling of IFN-I responses established the dynamic regulatory networks uncovering three temporal transcriptional waves. Perturbation of key transcription factors (TFs) and TF footprint analysis revealed two regulator modules with different temporal kinetics that control expression of coinhibitory receptors and IFN-I response genes, with SP140 highlighted as one of the key regulators that differentiates LAG-3 and TIGIT expression. Finally, we found that the dynamic IFN-I response in vitro closely mirrored T cell features in acute SARS-CoV-2 infection. The identification of unique TFs controlling coinhibitory receptor expression under IFN-I response may provide targets for enhancement of immunotherapy in cancer, infectious diseases and autoimmunity.


Subject(s)
COVID-19 , Interferon Type I , Gene Regulatory Networks , Humans , Interferon Type I/genetics , Receptors, Antigen, T-Cell/metabolism , Receptors, Immunologic/genetics , SARS-CoV-2 , T-Lymphocytes
3.
Sci Rep ; 12(1): 3890, 2022 03 10.
Article in English | MEDLINE | ID: covidwho-1740469

ABSTRACT

The new outbreak of coronavirus disease 2019 (COVID-19) has infected and caused the death of millions of people worldwide. Intensive efforts are underway around the world to establish effective treatments. Immunoglobulin from immunized animals or plasma from convalescent patients might constitute a specific treatment to guarantee the neutralization of the virus in the early stages of infection, especially in patients with risk factors and a high probability of progressing to severe disease. Worldwide, a few clinical trials using anti-SARS-CoV-2 immunoglobulins from horses immunized with the entire spike protein or fragments of it in the treatment of patients with COVID-19 are underway. Here, we describe the development of an anti-SARS-CoV-2 equine F(ab')2 immunoglobulin using a newly developed SARS-CoV-2 viral antigen that was purified and inactivated by radiation. Cell-based and preclinical assays showed that the F(ab')2 immunoglobulin successfully neutralizes the virus, is safe in animal models, and reduces the severity of the disease in a hamster model of SARS-CoV-2 infection and disease.


Subject(s)
COVID-19/therapy , Immunoglobulins/therapeutic use , Receptors, Immunologic/therapeutic use , SARS-CoV-2/immunology , Animals , Enzyme-Linked Immunosorbent Assay , Female , Horses/immunology , Humans , Immunoglobulins/immunology , Immunoglobulins/isolation & purification , Male , Mesocricetus/immunology , Plasmapheresis/veterinary , Receptors, Immunologic/immunology
4.
Cell Rep ; 38(10): 110434, 2022 03 08.
Article in English | MEDLINE | ID: covidwho-1729611

ABSTRACT

Type I interferons (IFN-I) are essential to establish antiviral innate immunity. Unanchored (or free) polyubiquitin (poly-Ub) has been shown to regulate IFN-I responses. However, few unanchored poly-Ub interactors are known. To identify factors regulated by unanchored poly-Ub in a physiological setting, we developed an approach to isolate unanchored poly-Ub from lung tissue. We identified the RNA helicase DHX16 as a potential pattern recognition receptor (PRR). Silencing of DHX16 in cells and in vivo diminished IFN-I responses against influenza virus. These effects extended to members of other virus families, including Zika and SARS-CoV-2. DHX16-dependent IFN-I production requires RIG-I and unanchored K48-poly-Ub synthesized by the E3-Ub ligase TRIM6. DHX16 recognizes a signal in influenza RNA segments that undergo splicing and requires its RNA helicase motif for direct, high-affinity interactions with specific viral RNAs. Our study establishes DHX16 as a PRR that partners with RIG-I for optimal activation of antiviral immunity requiring unanchored poly-Ub.


Subject(s)
DEAD Box Protein 58 , Interferon Type I , RNA Helicases , RNA, Viral , Receptors, Immunologic , Zika Virus Infection , Zika Virus , COVID-19 , DEAD Box Protein 58/immunology , Humans , Immunity, Innate , Interferon Type I/immunology , RNA Helicases/immunology , Receptors, Immunologic/immunology , SARS-CoV-2 , Tripartite Motif Proteins , Zika Virus/genetics , Zika Virus Infection/immunology
5.
Front Endocrinol (Lausanne) ; 12: 777130, 2021.
Article in English | MEDLINE | ID: covidwho-1662576

ABSTRACT

Objective: To identify clinical and biochemical characteristics associated with 7- & 30-day mortality and intensive care admission amongst diabetes patients admitted with COVID-19. Research Design and Methods: We conducted a cohort study collecting data from medical notes of hospitalised people with diabetes and COVID-19 in 7 hospitals within the Mersey-Cheshire region from 1 January to 30 June 2020. We also explored the impact on inpatient diabetes team resources. Univariate and multivariate logistic regression analyses were performed and optimised by splitting the dataset into a training, test, and validation sets, developing a robust predictive model for the primary outcome. Results: We analyzed data from 1004 diabetes patients (mean age 74.1 (± 12.6) years, predominantly men 60.7%). 45% belonged to the most deprived population quintile in the UK. Median BMI was 27.6 (IQR 23.9-32.4) kg/m2. The primary outcome (7-day mortality) occurred in 24%, increasing to 33% by day 30. Approximately one in ten patients required insulin infusion (9.8%). In univariate analyses, patients with type 2 diabetes had a higher risk of 7-day mortality [p < 0.05, OR 2.52 (1.06, 5.98)]. Patients requiring insulin infusion had a lower risk of death [p = 0.02, OR 0.5 (0.28, 0.9)]. CKD in younger patients (<70 years) had a greater risk of death [OR 2.74 (1.31-5.76)]. BMI, microvascular and macrovascular complications, HbA1c, and random non-fasting blood glucose on admission were not associated with mortality. On multivariate analysis, CRP and age remained associated with the primary outcome [OR 3.44 (2.17, 5.44)] allowing for a validated predictive model for death by day 7. Conclusions: Higher CRP and advanced age were associated with and predictive of death by day 7. However, BMI, presence of diabetes complications, and glycaemic control were not. A high proportion of these patients required insulin infusion warranting increased input from the inpatient diabetes teams.


Subject(s)
Biomarkers/blood , COVID-19/complications , Diabetes Mellitus, Type 2/mortality , Receptors, Immunologic/blood , SARS-CoV-2/isolation & purification , Age Factors , Aged , Aged, 80 and over , Blood Glucose/analysis , COVID-19/transmission , COVID-19/virology , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/virology , Female , Follow-Up Studies , Glycated Hemoglobin A/analysis , Hospitalization , Humans , Male , Middle Aged , Prognosis , Retrospective Studies , Survival Rate , United Kingdom/epidemiology
6.
Inflammation ; 45(3): 1348-1361, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1637685

ABSTRACT

The oral mucosa is one of the first lines of the innate host defense system against microbial invasion. Interferon (IFN) lambda-1 (IFN-λ1), a type III IFN, exhibits type I IFN-like antiviral activity. In contrast to ubiquitously expressed type I IFN receptors, IFN-λ receptor 1 (IFN-λR1), which has higher affinity for type III IFNs than low-affinity interleukin (IL)-10 receptor 2, is mainly expressed on epithelial cells. Although IFN-λ1 has been shown to exert antiviral effects in the respiratory tract, gastrointestinal tract, and skin, the regulation of type III IFN receptor expression and its functions in the oral mucosa remain unclear. We herein showed the expression of IFN-λR1 in human gingival keratinocytes. The expression of IL-6, angiotensin-converting enzyme 2 (a critical molecule for severe acute respiratory syndrome coronavirus 2 infection), and IL-8 in human primary gingival keratinocytes (HGK) were significantly higher following treatments with either type I IFN (IFN-ß) or type II IFN (IFN-γ) than with IFN-λ1. However, the IFN-λ1 treatment strongly induced toll-like receptor (TLR) 3 and retinoic acid-inducible gene I (RIG-I), which mainly recognize viral nucleic acids, via the STAT1-mediated pathway. Furthermore, a stimulation with a RIG-I or TLR3 agonist promoted the production of IL-6, IL-8, and IFN-λ in HGK, which was significantly enhanced by a pretreatment with IFN-λ1. These results suggest that IFN-λ1 may contribute to the activation of innate immune responses to oral viral infections by up-regulating the expression of RIG-I and TLR3 and priming their functions in keratinocytes.


Subject(s)
Interferons , /immunology , DEAD Box Protein 58/metabolism , Humans , Immunity, Innate , Interferons/immunology , Interferons/pharmacology , Interleukin-6 , Interleukin-8 , Mouth Mucosa/metabolism , Receptors, Immunologic/metabolism , Toll-Like Receptor 3/metabolism
7.
Genes (Basel) ; 13(1)2021 12 23.
Article in English | MEDLINE | ID: covidwho-1580896

ABSTRACT

ADAR1-mediated deamination of adenosines in long double-stranded RNAs plays an important role in modulating the innate immune response. However, recent investigations based on metatranscriptomic samples of COVID-19 patients and SARS-COV-2-infected Vero cells have recovered contrasting findings. Using RNAseq data from time course experiments of infected human cell lines and transcriptome data from Vero cells and clinical samples, we prove that A-to-G changes observed in SARS-COV-2 genomes represent genuine RNA editing events, likely mediated by ADAR1. While the A-to-I editing rate is generally low, changes are distributed along the entire viral genome, are overrepresented in exonic regions, and are (in the majority of cases) nonsynonymous. The impact of RNA editing on virus-host interactions could be relevant to identify potential targets for therapeutic interventions.


Subject(s)
Adenosine Deaminase/genetics , COVID-19/genetics , Genome, Viral , Host-Pathogen Interactions/genetics , RNA Editing , RNA, Viral/genetics , RNA-Binding Proteins/genetics , SARS-CoV-2/genetics , Adenosine/metabolism , Adenosine Deaminase/immunology , Animals , COVID-19/metabolism , COVID-19/virology , Cell Line, Tumor , Chlorocebus aethiops , DEAD Box Protein 58/genetics , DEAD Box Protein 58/immunology , Deamination , Epithelial Cells/immunology , Epithelial Cells/virology , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate , Inosine/metabolism , Interferon-Induced Helicase, IFIH1/genetics , Interferon-Induced Helicase, IFIH1/immunology , Interferon-beta/genetics , Interferon-beta/immunology , RNA, Double-Stranded/genetics , RNA, Double-Stranded/immunology , RNA, Viral/immunology , RNA-Binding Proteins/immunology , Receptors, Immunologic/genetics , Receptors, Immunologic/immunology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Transcriptome , Vero Cells
8.
Clinics (Sao Paulo) ; 76: e3547, 2021.
Article in English | MEDLINE | ID: covidwho-1574414

ABSTRACT

OBJECTIVE: Coronavirus disease 2019 (COVID-19) is associated with high mortality among hospitalized patients and incurs high costs. Severe acute respiratory syndrome coronavirus 2 infection can trigger both inflammatory and thrombotic processes, and these complications can lead to a poorer prognosis. This study aimed to evaluate the association and temporal trends of D-dimer and C-reactive protein (CRP) levels with the incidence of venous thromboembolism (VTE), hospital mortality, and costs among inpatients with COVID-19. METHODS: Data were extracted from electronic patient records and laboratory databases. Crude and adjusted associations for age, sex, number of comorbidities, Sequential Organ Failure Assessment score at admission, and D-dimer or CRP logistic regression models were used to evaluate associations. RESULTS: Between March and June 2020, COVID-19 was documented in 3,254 inpatients. The D-dimer level ≥4,000 ng/mL fibrinogen equivalent unit (FEU) mortality odds ratio (OR) was 4.48 (adjusted OR: 1.97). The CRP level ≥220 mg/dL OR for death was 7.73 (adjusted OR: 3.93). The D-dimer level ≥4,000 ng/mL FEU VTE OR was 3.96 (adjusted OR: 3.26). The CRP level ≥220 mg/dL OR for VTE was 2.71 (adjusted OR: 1.92). All these analyses were statistically significant (p<0.001). Stratified hospital costs demonstrated a dose-response pattern. Adjusted D-dimer and CRP levels were associated with higher mortality and doubled hospital costs. In the first week, elevated D-dimer levels predicted VTE occurrence and systemic inflammatory harm, while CRP was a hospital mortality predictor. CONCLUSION: D-dimer and CRP levels were associated with higher hospital mortality and a higher incidence of VTE. D-dimer was more strongly associated with VTE, although its discriminative ability was poor, while CRP was a stronger predictor of hospital mortality. Their use outside the usual indications should not be modified and should be discouraged.


Subject(s)
Biomarkers , COVID-19 , Biomarkers/analysis , C-Reactive Protein , COVID-19/diagnosis , COVID-19/therapy , Fibrin Fibrinogen Degradation Products , Humans , Prospective Studies , Receptors, Immunologic/analysis , SARS-CoV-2
9.
Nat Methods ; 18(6): 627-630, 2021 06.
Article in English | MEDLINE | ID: covidwho-1550331

ABSTRACT

We introduce the TRUST4 open-source algorithm for reconstruction of immune receptor repertoires in αß/γδ T cells and B cells from RNA-sequencing (RNA-seq) data. Compared with competing methods, TRUST4 supports both FASTQ and BAM format and is faster and more sensitive in assembling longer-even full-length-receptor repertoires. TRUST4 can also call repertoire sequences from single-cell RNA-seq (scRNA-seq) data without V(D)J enrichment, and is compatible with both SMART-seq and 5' 10x Genomics platforms.


Subject(s)
Algorithms , Receptors, Immunologic/genetics , Sequence Analysis, RNA/methods , Single-Cell Analysis/methods , Receptors, Antigen, B-Cell/genetics , Receptors, Antigen, T-Cell/genetics , V(D)J Recombination
10.
Clin Lab ; 67(12)2021 Dec 01.
Article in English | MEDLINE | ID: covidwho-1538779

ABSTRACT

BACKGROUND: Coronavirus disease, which initially appeared in Wuhan, China during the month of December 2019, very quickly spread and became a worldwide pandemic. The African continent was not spared. The poor health system and low socioeconomic status in some regions has raised concern on the risk of an epidemic disaster due to the rapid transmission of the virus. This study therefore aims to determine the relationship between the modifications of complete blood count parameters, CRP, and the severity and outcome of SARS-CoV2 infection in the first patients hospitalized at the Centre Hospitalier Universitaire de Libreville (Libreville University Hospital Center) in Gabon. METHODS: This is a prospective study led from April to July 2020 in the COVID infectious department (SICov) of the Centre Hospitalier Universitaire de Libreville (CHUL). RESULTS: In total, 184 patients participated in the study. The median age was 47 (37 - 54) years. Male subjects predominated. The median number of leucocytes was 5.6 (4.4 - 7.45) x 109/L. It was significantly higher in patients with acute respiratory distress syndrome (ARDS) and in intensive care units (ICU) compared to pauci-symptomatic cases (p < 0.01). Factors associated with death were leukocytosis (crude OR 37.1 (8.3 - 98.4) p < 0.01), neutrophilia (OR 20.1 (4.6 - 89.0) p < 0.01), NRL ≥ 9 (OR 13.5 (2.7 - 67.4); p < 0.01) and CRP > 100 mg/L (OR 17.8 (2.0 - 154.0) p = 0.02). CONCLUSIONS: The hematological profile of patients with COVID-19 varies according to the severity of the disease. Leukocytosis, neutrophilia, a NLR above 6 and a CRP higher than 100 mg/L were associated with the severity of the infection and death in Gabonese patients.


Subject(s)
C-Reactive Protein , COVID-19 , Receptors, Immunologic , Blood Cell Count , Humans , Male , Middle Aged , Patient Acuity , Prospective Studies , RNA, Viral , Receptors, Immunologic/analysis , SARS-CoV-2
11.
Viruses ; 13(8)2021 08 23.
Article in English | MEDLINE | ID: covidwho-1524167

ABSTRACT

The pandemic of COVID-19 caused by SARS-CoV-2 continues to spread despite the global efforts taken to control it. The 3C-like protease (3CLpro), the major protease of SARS-CoV-2, is one of the most interesting targets for antiviral drug development because it is highly conserved among SARS-CoVs and plays an important role in viral replication. Herein, we developed high throughput screening for SARS-CoV-2 3CLpro inhibitor based on AlphaScreen. We screened 91 natural product compounds and found that all-trans retinoic acid (ATRA), an FDA-approved drug, inhibited 3CLpro activity. The 3CLpro inhibitory effect of ATRA was confirmed in vitro by both immunoblotting and AlphaScreen with a 50% inhibition concentration (IC50) of 24.7 ± 1.65 µM. ATRA inhibited the replication of SARS-CoV-2 in VeroE6/TMPRSS2 and Calu-3 cells, with IC50 = 2.69 ± 0.09 µM in the former and 0.82 ± 0.01 µM in the latter. Further, we showed the anti-SARS-CoV-2 effect of ATRA on the currently circulating variants of concern (VOC); alpha, beta, gamma, and delta. These results suggest that ATRA may be considered as a potential therapeutic agent against SARS-CoV-2.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , SARS-CoV-2/drug effects , Tretinoin/pharmacology , Animals , Cell Line, Tumor , Chlorocebus aethiops , Cysteine Proteinase Inhibitors/pharmacology , DEAD Box Protein 58/metabolism , High-Throughput Screening Assays , Humans , Receptors, Immunologic/metabolism , SARS-CoV-2/enzymology , SARS-CoV-2/physiology , Vero Cells , Virus Replication/drug effects
12.
Eur J Neurol ; 28(8): 2603-2613, 2021 08.
Article in English | MEDLINE | ID: covidwho-1518029

ABSTRACT

BACKGROUND AND PURPOSE: Nasu-Hakola disease (NHD) is a rare, autosomal recessive disorder characterized by skeletal and neurological symptoms. Behavioral symptoms with cognitive impairment may mimic the behavioral variant of frontotemporal dementia (bvFTD) and other early-onset dementias. Our patients were analyzed and the literature was reviewed to delineate neurological and neuroimaging findings suggestive of NHD. METHOD: Fourteen patients carrying a pathogenic mutation in the TREM2 gene were found in our database. Demographic, clinical, laboratory and radiological data were retrieved and analyzed. RESULTS: The presenting clinical picture was behavioral changes with cognitive decline resembling bvFTD in all patients. The mean age was 37.1 ± 4.97 years and the mean duration of the disease was 8.9 ± 3.51 years. Only two patients had typical bone cysts. Seven patients had bilateral calcification of the basal ganglia in computed tomography of the brain. Magnetic resonance imaging of the brain revealed severe atrophy of the corpus callosum, enlargement of the ventricles, atrophy of the caudate nuclei and periventricular white matter changes in all patients. Symmetrical global atrophy of the brain mainly affecting frontoparietal and lateral temporal regions were observed in all cases, and 13 patients had atrophy of the hippocampus. Cerebrospinal fluid examination of 10 patients showed elevated protein levels in six and the presence of oligoclonal bands in four patients. CONCLUSION: A combination of white matter changes, enlarged ventricles, atrophy of the caudate nuclei and thinning of the corpus callosum in magnetic resonance imaging strongly suggests NHD in patients with FTD syndrome. Molecular genetic analysis should be performed in suspected cases, and families should receive genetic counseling.


Subject(s)
Frontotemporal Dementia , Lipodystrophy , Membrane Glycoproteins/genetics , Osteochondrodysplasias , Receptors, Immunologic/genetics , Subacute Sclerosing Panencephalitis , Adult , Brain/diagnostic imaging , Frontotemporal Dementia/diagnostic imaging , Frontotemporal Dementia/genetics , Humans , Magnetic Resonance Imaging , Neuroimaging
13.
Toxicol Appl Pharmacol ; 434: 115796, 2022 01 01.
Article in English | MEDLINE | ID: covidwho-1510333

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has required the urgent development of new therapies, among which passive immunotherapy is contemplated. CoviFab (INM005) is a RBD-specific F(ab')2 fragment derived from equine polyclonal antibodies. We investigate their preclinical security and biodistribution by in vivo and ex vivo NIR imaging after intravenous administration of a dose of 4 mg/kg at time 0 and 48 h. Images were taken at 1, 12, 24, 36, 48, 49, 60, 72, 84, 96, 108, 120, 132 and 144 h after the first intravenous injection. At 96 and 144 h, mice were sacrificed for haematology, serum chemistry, clinical pathology, histopathology and ex vivo imaging. The biodistribution profile was similar in all organs studied, with the highest fluorescence at 1 h after each injection, gradually decreasing after that each one and until the end of the study (144 h). The toxicology study revealed no significant changes in the haematology and serum chemistry parameters. Further, there were no changes in the gross and histological examination of organs. Nonclinical data of the current study confirm that CoviFab is safe, without observable adverse effects in mice. Furthermore, we confirm that bioimaging studies are a useful approach in preclinical trials to determine biodistribution.


Subject(s)
Antibodies, Viral/metabolism , COVID-19/drug therapy , Receptors, Immunologic/metabolism , Recombinant Proteins/metabolism , SARS-CoV-2/metabolism , Administration, Intravenous , Animals , Antibodies, Viral/administration & dosage , Antibodies, Viral/adverse effects , COVID-19/metabolism , COVID-19/prevention & control , HEK293 Cells , Horses , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Transgenic , Receptors, Immunologic/administration & dosage , Recombinant Proteins/administration & dosage , Recombinant Proteins/adverse effects , SARS-CoV-2/drug effects , Spectroscopy, Near-Infrared/methods , Tissue Distribution/drug effects , Tissue Distribution/physiology
14.
J Clin Invest ; 131(21)2021 11 01.
Article in English | MEDLINE | ID: covidwho-1495789

ABSTRACT

To explore how the immune system controls clearance of SARS-CoV-2, we used a single-cell, mass cytometry-based proteomics platform to profile the immune systems of 21 patients who had recovered from SARS-CoV-2 infection without need for admission to an intensive care unit or for mechanical ventilation. We focused on receptors involved in interactions between immune cells and virus-infected cells. We found that the diversity of receptor repertoires on natural killer (NK) cells was negatively correlated with the viral clearance rate. In addition, NK subsets expressing the receptor DNAM1 were increased in patients who more rapidly recovered from infection. Ex vivo functional studies revealed that NK subpopulations with high DNAM1 expression had cytolytic activities in response to target cell stimulation. We also found that SARS-CoV-2 infection induced the expression of CD155 and nectin-4, ligands of DNAM1 and its paired coinhibitory receptor TIGIT, which counterbalanced the cytolytic activities of NK cells. Collectively, our results link the cytolytic immune responses of NK cells to the clearance of SARS-CoV-2 and show that the DNAM1 pathway modulates host-pathogen interactions during SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , COVID-19/virology , Killer Cells, Natural/immunology , Receptors, Natural Killer Cell/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Animals , Antigens, Differentiation, T-Lymphocyte/immunology , Cell Adhesion Molecules/immunology , Cohort Studies , Cytotoxicity, Immunologic , Female , Heterografts , Host Microbial Interactions/immunology , Humans , Immunophenotyping , In Vitro Techniques , Ligands , Male , Mice , Mice, SCID , Middle Aged , NK Cell Lectin-Like Receptor Subfamily D/immunology , Pandemics , Receptors, Immunologic/immunology , Receptors, Virus/immunology , Viral Load , Young Adult
15.
Acc Chem Res ; 54(21): 4012-4023, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1483069

ABSTRACT

In vitro-transcribed RNAs are emerging as new biologics for therapeutic innovation, as exemplified by their application recently in SARS-CoV-2 vaccinations. RNAs prepared by in vitro transcription (IVT) allow transient expression of proteins of interest, conferring safety over DNA- or virus-mediated gene delivery systems. However, in vitro-transcribed RNAs should be used with caution because of their immunogenicity, which is in part triggered by double-stranded RNA (dsRNA) byproducts during IVT. Cellular innate immune response to dsRNA byproducts can lead to undesirable consequences, including suppression of protein synthesis and cell death, which in turn can detrimentally impact the efficacy of mRNA therapy. Thus, it is critical to understand the nature of IVT byproducts and the mechanisms by which they trigger innate immune responses.Our lab has been investigating the mechanisms by which the innate immune system discriminates between "self" and "nonself" RNA, with the focus on the cytoplasmic dsRNA receptors retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated 5 (MDA5). We have biochemically and structurally characterized critical events involving RNA discrimination and signal transduction by RIG-I or MDA5. We have used in vitro-transcribed RNAs as tools to investigate RNA specificity of RIG-I and MDA5, which required optimization of the IVT reaction and purification processes to eliminate the effect of IVT byproducts. In this Account, we summarize our current understanding of RIG-I and MDA5 and IVT reactions and propose future directions for improving IVT as a method to generate both research tools and therapeutics. Other critical proteins in cellular innate immune response to dsRNAs are also discussed. We arrange the contents in the following order: (i) innate immunity sensors for nonself RNA, including the RIG-I-like receptors (RLRs) in the cytosol and the toll-like receptors (TLRs) in the endosome, as well as cytoplasmic dsRNA-responding proteins, including protein kinase R (PKR) and 2',5'-oligoadenylate synthetases (OASes), illustrating the feature of protein-RNA binding and its consequences; (ii) the immunogenicity of IVT byproducts, specifically the generation of dsRNA molecules during IVT; and (iii) methods to reduce IVT RNA immunogenicity, including optimizations of RNA polymerases, reagents, and experimental conditions during IVT and subsequent purification.


Subject(s)
RNA, Viral/immunology , SARS-CoV-2/genetics , DEAD Box Protein 58/genetics , DEAD Box Protein 58/immunology , Humans , Immunity, Innate/genetics , Immunity, Innate/immunology , Interferon-Induced Helicase, IFIH1/genetics , Interferon-Induced Helicase, IFIH1/immunology , RNA, Viral/genetics , Receptors, Immunologic/genetics , Receptors, Immunologic/immunology , SARS-CoV-2/immunology
16.
Front Immunol ; 12: 729189, 2021.
Article in English | MEDLINE | ID: covidwho-1450809

ABSTRACT

Several SARS-CoV-2 vaccines have received EUAs, but many issues remain unresolved, including duration of conferred immunity and breadth of cross-protection. Adjuvants that enhance and shape adaptive immune responses that confer broad protection against SARS-CoV-2 variants will be pivotal for long-term protection as drift variants continue to emerge. We developed an intranasal, rationally designed adjuvant integrating a nanoemulsion (NE) that activates TLRs and NLRP3 with an RNA agonist of RIG-I (IVT DI). The combination adjuvant with spike protein antigen elicited robust responses to SARS-CoV-2 in mice, with markedly enhanced TH1-biased cellular responses and high virus-neutralizing antibody titers towards both homologous SARS-CoV-2 and a variant harboring the N501Y mutation shared by B1.1.7, B.1.351 and P.1 variants. Furthermore, passive transfer of vaccination-induced antibodies protected naive mice against heterologous viral challenge. NE/IVT DI enables mucosal vaccination, and has the potential to improve the immune profile of a variety of SARS-CoV-2 vaccine candidates to provide effective cross-protection against future drift variants.


Subject(s)
Adjuvants, Immunologic/pharmacology , Antibodies, Viral/immunology , COVID-19 Vaccines/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Vaccines, Synthetic/immunology , Adaptive Immunity/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Chlorocebus aethiops , Cross Protection/immunology , DEAD Box Protein 58 , HEK293 Cells , Humans , Immunity, Humoral/immunology , Immunization, Passive , Mice , Mice, Inbred C57BL , Receptors, Immunologic/agonists , Recombinant Proteins/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination , Vero Cells
17.
Curr Issues Mol Biol ; 43(3): 1212-1225, 2021 Sep 22.
Article in English | MEDLINE | ID: covidwho-1438531

ABSTRACT

The coronavirus SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Most SARS-CoV-2 infections are mild or even asymptomatic. However, a small fraction of infected individuals develops severe, life-threatening disease, which is caused by an uncontrolled immune response resulting in hyperinflammation. However, the factors predisposing individuals to severe disease remain poorly understood. Here, we show that levels of CD47, which is known to mediate immune escape in cancer and virus-infected cells, are elevated in SARS-CoV-2-infected Caco-2 cells, Calu-3 cells, and air-liquid interface cultures of primary human bronchial epithelial cells. Moreover, SARS-CoV-2 infection increases SIRPalpha levels, the binding partner of CD47, on primary human monocytes. Systematic literature searches further indicated that known risk factors such as older age and diabetes are associated with increased CD47 levels. High CD47 levels contribute to vascular disease, vasoconstriction, and hypertension, conditions that may predispose SARS-CoV-2-infected individuals to COVID-19-related complications such as pulmonary hypertension, lung fibrosis, myocardial injury, stroke, and acute kidney injury. Hence, age-related and virus-induced CD47 expression is a candidate mechanism potentially contributing to severe COVID-19, as well as a therapeutic target, which may be addressed by antibodies and small molecules. Further research will be needed to investigate the potential involvement of CD47 and SIRPalpha in COVID-19 pathology. Our data should encourage other research groups to consider the potential relevance of the CD47/ SIRPalpha axis in their COVID-19 research.


Subject(s)
Antigens, Differentiation/metabolism , CD47 Antigen/metabolism , COVID-19/epidemiology , COVID-19/metabolism , Pandemics , Receptors, Immunologic/metabolism , SARS-CoV-2/metabolism , Severity of Illness Index , Signal Transduction/immunology , Blood Donors , Blotting, Western/methods , Bronchi/cytology , COVID-19/pathology , COVID-19/virology , Caco-2 Cells , Epithelial Cells/metabolism , Epithelial Cells/virology , Healthy Volunteers , Humans , Monocytes/metabolism , Monocytes/virology , Polymerase Chain Reaction/methods , RNA, Viral/genetics , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification
18.
Int Immunopharmacol ; 101(Pt A): 108192, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1433412

ABSTRACT

The mounting evidence regarding the pathogenesis of COVID-19 indicated that the cytokine storm has an axial role in the severity of this disease, which may lead to thrombotic complications, acute respiratory distress syndrome (ARDS), and myocardial damage, among other consequences. It has recently been demonstrated that statins are known to have anti-viral, anti-inflammatory, anti-thrombotic, and immunomodulatory features; however, their advantage has not been evaluated in COVID-19. This study aimed to investigate the protective effects of lovastatin in intensive care unit (ICU) patients with COVID-19. The case-control study consists of 284 ICU patients, which classified into three groups as follows: 1) the patients who no received lovastatin as a control (92 patients), 2) patients received 20 mg per day lovastatin (99 patients), and 3) patients received 40 mg per day lovastatin (93 patients). Each group's demographic and clinical parameters, along with CRP, interleukin (IL)-6, IL-8 levels, and mortality rate, were studied in three-time points. The results showed that there was no statistically significant difference between our study groups in terms of age and sex. (P > 0.05). Besides, in patients, receiving lovastatin the CRP, IL-6, IL-8 levels were significantly decreased from T1 to T3 than to the control group. Our results also showed that the use of lovastatin in COVID-19 patients significantly reduced the length of hospitalization in the ICU compared with the control group. In addition, our results showed that the mortality rate in patients receiving lovastatin was lower when compared to the control group; however, this difference was not statistically significant. Since the cytokine storm is a significant factor in the pathology of SARS-CoV-2, our findings highlighted the potential use of lovastatin to mitigate the inflammatory response induced by SARS-CoV-2 infection.


Subject(s)
Anti-Inflammatory Agents/pharmacology , COVID-19/drug therapy , Lovastatin/pharmacology , Adult , Anti-Inflammatory Agents/therapeutic use , COVID-19/blood , Case-Control Studies , Critical Care/methods , Cytokine Release Syndrome/blood , Cytokine Release Syndrome/drug therapy , Cytokines/drug effects , Female , Hospitalization , Humans , Intensive Care Units , Interleukin-6/metabolism , Interleukin-8/metabolism , Lovastatin/therapeutic use , Male , Middle Aged , Receptors, Immunologic/metabolism , Sex Factors
19.
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
20.
PLoS One ; 16(9): e0256931, 2021.
Article in English | MEDLINE | ID: covidwho-1403305

ABSTRACT

BACKGROUND: The objective of this cohort study was to determine whether elevated CRP in early COVID-19 was associated with 14-day mortality in geriatric patients. METHODS: Plasma CRP levels at hospital admission and 14-day all-cause mortality were assessed in geriatric inpatients hospitalized for COVID-19. Potential confounders were age, sex, functional abilities, history of malignancies, hypertension, cardiomyopathy, albuminemia, number of acute health issues, use of antibiotics and respiratory treatments. RESULTS: Ninety-five participants (mean±SD 88.0±5.5years; 49.5%women; mean CRP, 76.7±77.5mg/L; mean albuminemia, 32.9±6.0g/L) were included. Sixteen participants who did not survive at day 14 exhibited higher CRP level at baseline than the others (120.3±71.2 versus 67.9±76.1 mg/L, P = 0.002). There was no difference in albuminemia (P = 0.329). Plasma CRP level was directly associated with 14-day mortality (fully adjusted HR = 1.11, P = 0.025). The cut-off for CRP associated with 14-day mortality was set at 35mg/L (sensitivity = 0.88; specificity = 0.56). Those with CRP<35mg/L had longer survival time than the others (log-rank P<0.001). CONCLUSIONS: Elevated CRP levels were associated with poorer 14-day survival in hospitalized geriatric COVID-19 patients.


Subject(s)
COVID-19 , Receptors, Immunologic/blood , Aged, 80 and over , Biomarkers/blood , COVID-19/blood , COVID-19/mortality , Female , Humans , Longitudinal Studies , Male , Prognosis , Risk Factors
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