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1.
J Allergy Clin Immunol ; 147(1): 81-91, 2021 01.
Article in English | MEDLINE | ID: covidwho-2095538

ABSTRACT

BACKGROUND: Severe immunopathology may drive the deleterious manifestations that are observed in the advanced stages of coronavirus disease 2019 (COVID-19) but are poorly understood. OBJECTIVE: Our aim was to phenotype leukocyte subpopulations and the cytokine milieu in the lungs and blood of critically ill patients with COVID-19 acute respiratory distress syndrome (ARDS). METHODS: We consecutively included patients less than 72 hours after intubation following informed consent from their next of kin. Bronchoalveolar lavage fluid was evaluated by microscopy; bronchoalveolar lavage fluid and blood were assessed by 10-color flow cytometry and a multiplex cytokine panel. RESULTS: Four mechanically ventilated patients (aged 40-75 years) with moderate-to-severe COVID-19 ARDS were included. Immature neutrophils dominated in both blood and lungs, whereas CD4 and CD8 T-cell lymphopenia was observed in the 2 compartments. However, regulatory T cells and TH17 cells were found in higher fractions in the lung. Lung CD4 and CD8 T cells and macrophages expressed an even higher upregulation of activation markers than in blood. A wide range of cytokines were expressed at high levels both in the blood and in the lungs, most notably, IL-1RA, IL-6, IL-8, IP-10, and monocyte chemoattactant protein-1, consistent with hyperinflammation. CONCLUSION: COVID-19 ARDS exhibits a distinct immunologic profile in the lungs, with a depleted and exhausted CD4 and CD8 T-cell population that resides within a heavily hyperinflammatory milieu.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Lung/immunology , Lymphopenia/immunology , Respiratory Distress Syndrome/immunology , SARS-CoV-2/immunology , Th17 Cells/immunology , Adult , Aged , CD8-Positive T-Lymphocytes/pathology , COVID-19/pathology , Cross-Sectional Studies , Cytokines/immunology , Female , Humans , Immunophenotyping , Lung/pathology , Lymphopenia/pathology , Male , Middle Aged , Respiratory Distress Syndrome/pathology , Th17 Cells/pathology
2.
Front Immunol ; 12: 785349, 2021.
Article in English | MEDLINE | ID: covidwho-1911033

ABSTRACT

SARS-CoV-2 infections present a tremendous threat to public health. Safe and efficacious vaccines are the most effective means in preventing the infections. A variety of vaccines have demonstrated excellent efficacy and safety around the globe. Yet, development of alternative forms of vaccines remains beneficial, particularly those with simpler production processes, less stringent storage conditions, and the capability of being used in heterologous prime/boost regimens which have shown improved efficacy against many diseases. Here we reported a novel DNA vaccine comprised of the SARS-CoV-2 spike protein fused with CD40 ligand (CD40L) serving as both a targeting ligand and molecular adjuvant. A single intramuscular injection in Syrian hamsters induced significant neutralizing antibodies 3-weeks after vaccination, with a boost substantially improving immune responses. Moreover, the vaccine also reduced weight loss and suppressed viral replication in the lungs and nasal turbinates of challenged animals. Finally, the incorporation of CD40L into the DNA vaccine was shown to reduce lung pathology more effectively than the DNA vaccine devoid of CD40L. These results collectively indicate that this DNA vaccine candidate could be further explored because of its efficacy and known safety profile.


Subject(s)
CD40 Ligand/immunology , COVID-19/immunology , Mesocricetus/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/immunology , Adjuvants, Immunologic/pharmacology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/virology , Cell Line , Female , HEK293 Cells , Humans , Lung/immunology , Lung/virology , Mesocricetus/virology , Models, Animal , Vaccination/methods , Vaccines, Inactivated/immunology
3.
Front Immunol ; 13: 835156, 2022.
Article in English | MEDLINE | ID: covidwho-1902991

ABSTRACT

Complement plays an important role in the direct defense to pathogens, but can also activate immune cells and the release of pro-inflammatory cytokines. However, in critically ill patients with COVID-19 the immune system is inadequately activated leading to severe acute respiratory syndrome (SARS) and acute kidney injury, which is associated with higher mortality. Therefore, we characterized local complement deposition as a sign of activation in both lungs and kidneys from patients with severe COVID-19. Using immunohistochemistry we investigated deposition of complement factors C1q, MASP-2, factor D (CFD), C3c, C3d and C5b-9 as well as myeloperoxidase (MPO) positive neutrophils and SARS-CoV-2 virus particles in lungs and kidneys from 38 patients who died from COVID-19. In addition, tissue damage was analyzed using semi-quantitative scores followed by correlation with complement deposition. Autopsy material from non-COVID patients who died from cardiovascular causes, cerebral hemorrhage and pulmonary embolism served as control (n=8). Lung injury in samples from COVID-19 patients was significantly more pronounced compared to controls with formation of hyaline membranes, thrombi and edema. In addition, in the kidney tubular injury was higher in these patients and correlated with lung injury (r=0.361*). In autopsy samples SARS-CoV-2 spike protein was detected in 22% of the lungs of COVID-19 patients but was lacking in kidneys. Complement activation was significantly stronger in lung samples from patients with COVID-19 via the lectin and alternative pathway as indicated by deposition of MASP-2, CFD, C3d and C5b9. Deposits in the lung were predominantly detected along the alveolar septa, the hyaline membranes and in the alveolar lumina. In the kidney, complement was significantly more deposited in patients with COVID-19 in peritubular capillaries and tubular basement membranes. Renal COVID-19-induced complement activation occurred via the lectin pathway, while activation of the alternative pathway was similar in both groups. Furthermore, MPO-positive neutrophils were found in significantly higher numbers in lungs and kidneys of COVID-19 patients and correlated with local MASP-2 deposition. In conclusion, in patients who died from SARS-CoV-2 infection complement was activated in both lungs and kidneys indicating that complement might be involved in systemic worsening of the inflammatory response. Complement inhibition might thus be a promising treatment option to prevent deregulated activation and subsequent collateral tissue injury in COVID-19.


Subject(s)
COVID-19/immunology , Complement Pathway, Alternative/immunology , Lectins/immunology , Aged , Aged, 80 and over , Autopsy , COVID-19/pathology , COVID-19/virology , Complement System Proteins/immunology , Female , Humans , Kidney/immunology , Kidney/pathology , Kidney/virology , Lung/immunology , Lung/pathology , Lung/virology , Male , Middle Aged , Neutrophils/immunology , Peroxidase/immunology , SARS-CoV-2/immunology
4.
JCI Insight ; 7(5)2022 03 08.
Article in English | MEDLINE | ID: covidwho-1759583

ABSTRACT

Severe acute lung injury has few treatment options and a high mortality rate. Upon injury, neutrophils infiltrate the lungs and form neutrophil extracellular traps (NETs), damaging the lungs and driving an exacerbated immune response. Unfortunately, no drug preventing NET formation has completed clinical development. Here, we report that disulfiram - an FDA-approved drug for alcohol use disorder - dramatically reduced NETs, increased survival, improved blood oxygenation, and reduced lung edema in a transfusion-related acute lung injury (TRALI) mouse model. We then tested whether disulfiram could confer protection in the context of SARS-CoV-2 infection, as NETs are elevated in patients with severe COVID-19. In SARS-CoV-2-infected golden hamsters, disulfiram reduced NETs and perivascular fibrosis in the lungs, and it downregulated innate immune and complement/coagulation pathways, suggesting that it could be beneficial for patients with COVID-19. In conclusion, an existing FDA-approved drug can block NET formation and improve disease course in 2 rodent models of lung injury for which treatment options are limited.


Subject(s)
Acute Lung Injury/drug therapy , COVID-19/complications , Disulfiram/pharmacology , Extracellular Traps/drug effects , Lung/immunology , SARS-CoV-2 , Acetaldehyde Dehydrogenase Inhibitors/pharmacology , Acute Lung Injury/etiology , Animals , COVID-19/virology , Disease Models, Animal , Extracellular Traps/immunology , Rodentia
5.
Commun Biol ; 5(1): 242, 2022 03 18.
Article in English | MEDLINE | ID: covidwho-1751765

ABSTRACT

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), has incited a global health crisis. Currently, there are limited therapeutic options for the prevention and treatment of SARS-CoV-2 infections. We evaluated the antiviral activity of sulforaphane (SFN), the principal biologically active phytochemical derived from glucoraphanin, the naturally occurring precursor present in high concentrations in cruciferous vegetables. SFN inhibited in vitro replication of six strains of SARS-CoV-2, including Delta and Omicron, as well as that of the seasonal coronavirus HCoV-OC43. Further, SFN and remdesivir interacted synergistically to inhibit coronavirus infection in vitro. Prophylactic administration of SFN to K18-hACE2 mice prior to intranasal SARS-CoV-2 infection significantly decreased the viral load in the lungs and upper respiratory tract and reduced lung injury and pulmonary pathology compared to untreated infected mice. SFN treatment diminished immune cell activation in the lungs, including significantly lower recruitment of myeloid cells and a reduction in T cell activation and cytokine production. Our results suggest that SFN should be explored as a potential agent for the prevention or treatment of coronavirus infections.


Subject(s)
Antiviral Agents/therapeutic use , Common Cold/drug therapy , Coronavirus Infections/drug therapy , Coronavirus OC43, Human , Isothiocyanates/therapeutic use , SARS-CoV-2 , Sulfoxides/therapeutic use , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/therapeutic use , Alanine/analogs & derivatives , Alanine/therapeutic use , Animals , COVID-19/drug therapy , Caco-2 Cells , Chlorocebus aethiops , Common Cold/virology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Cytokines/immunology , Drug Synergism , Humans , Lung/immunology , Lung/virology , Macrophages, Alveolar/immunology , Male , Mice, Transgenic , Spleen/immunology , T-Lymphocytes/immunology , Vero Cells , Viral Load
6.
Microbiol Spectr ; 10(1): e0236221, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1705650

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that causes coronavirus disease 2019 (COVID-19). However, the long-term health consequences of COVID-19 are not fully understood. We aimed to determine the long-term lung pathology and blood chemistry changes in Syrian hamsters infected with SARS-CoV-2. Syrian hamsters (Mesocricetus auratus) were inoculated with 105 PFU of SARS-CoV-2, and changes post-infection (pi) were observed for 20 days. On days 5 and 20 pi, the lungs were harvested and processed for pathology and viral load count. Multiple blood samples were collected every 3 to 5 days to observe dynamic changes in blood chemistry. Infected hamsters showed consistent weight loss until day 7 pi At day 5 pi, histopathology of the lungs showed moderate to severe inflammation and the virus could be detected. These results indicate that SARS-CoV-2 has an acute onset and recovery course in the hamster infection model. During the acute onset, blood triglyceride levels increased significantly at day 3 pi During the recovery course, uric acid and low-density lipoprotein levels increased significantly, but the total protein and albumin levels decreased. Together, our study suggests that SARS-CoV-2 infection in hamsters not only causes lung damage but also causes long-term changes in blood biochemistry during the recovery process. IMPORTANCE COVID-19 is now considered a multiorgan disease with a wide range of manifestations. There are increasing reports of persistent and long-term effects after acute COVID-19, but the long-term health consequences of COVID-19 are not fully understood. This study reported for the first time the use of blood samples collected continuously in a SARS-CoV-2-infected hamster model, which provides more information about the dynamic changes in blood biochemistry during the acute and recovery phases of SARS-CoV-2 infection. Our study suggests that SARS-CoV-2 infection in hamsters not only causes lung damage but also causes long-term changes in blood biochemistry during the recovery process. The study may be used by several researchers and clinicians, especially those who are studying potential treatments for patients with post-acute COVID-19 syndrome.


Subject(s)
COVID-19/complications , SARS-CoV-2/physiology , Animals , COVID-19/blood , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Cricetinae , Disease Models, Animal , Humans , Lipoproteins, LDL/blood , Lung/immunology , Lung/pathology , Lung/virology , Male , Mesocricetus , Uric Acid/blood
7.
Front Immunol ; 12: 796094, 2021.
Article in English | MEDLINE | ID: covidwho-1690446

ABSTRACT

It is still controversial whether chronic lung inflammation increases the risk for COVID-19. One of the risk factors for acquiring COVID-19 is the level of expression of SARS-CoV-2 entry receptors, ACE2 and TMPRSS2, in lung tissue. It is, however, not clear how lung tissue inflammation affects expression levels of these receptors. We hence aimed to determine the level of SARS-CoV-2 receptors in lung tissue of asthmatic relative to age, gender, and asthma severity, and to investigate the factors regulating that. Therefore, gene expression data sets of well-known asthmatic cohorts (SARP and U-BIOPRED) were used to evaluate the association of ACE2 and TMPRSS2 with age, gender of the asthmatic patients, and also the type of the underlying lung tissue inflammatory cytokines. Notably, ACE2 and to less extent TMPRSS2 expression were upregulated in the lung tissue of asthmatics compared to healthy controls. Although a differential expression of ACE2, but not TMPRSS2 was observed relative to age within the moderate and severe asthma groups, our data suggest that age may not be a key regulatory factor of its expression. The type of tissue inflammation, however, associated significantly with ACE2 and TMPRSS2 expression levels following adjusting with age, gender and oral corticosteroids use of the patient. Type I cytokine (IFN-γ), IL-8, and IL-19 were associated with increased expression, while Type II cytokines (IL-4 and IL-13) with lower expression of ACE2 in lung tissue (airway epithelium and/or lung biopsies) of moderate and severe asthmatic patients. Of note, IL-19 was associated with ACE2 expression while IL-17 was associated with TMPRSS2 expression in sputum of asthmatic subjects. In vitro treatment of bronchial fibroblasts with IL-17 and IL-19 cytokines confirmed the regulatory effect of these cytokines on SARS-CoV-2 entry receptors. Our results suggest that the type of inflammation may regulate ACE2 and TMPRSS2 expression in the lung tissue of asthmatics and may hence affect susceptibility to SARS-CoV-2 infection.


Subject(s)
Angiotensin-Converting Enzyme 2/immunology , Asthma/immunology , COVID-19/immunology , Cytokines/immunology , Gene Expression Regulation/immunology , Lung/immunology , SARS-CoV-2/immunology , Adult , Female , Humans , Male , Middle Aged , Serine Endopeptidases/immunology
8.
J Immunol ; 208(6): 1467-1482, 2022 03 15.
Article in English | MEDLINE | ID: covidwho-1690085

ABSTRACT

Asthma is a chronic disease of childhood, but for unknown reasons, disease activity sometimes subsides as children mature. In this study, we present clinical and animal model evidence suggesting that the age dependency of childhood asthma stems from an evolving host response to respiratory viral infection. Using clinical data, we show that societal suppression of respiratory virus transmission during coronavirus disease 2019 lockdown disrupted the traditional age gradient in pediatric asthma exacerbations, connecting the phenomenon of asthma remission to virus exposure. In mice, we show that asthmatic lung pathology triggered by Sendai virus (SeV) or influenza A virus is highly age-sensitive: robust in juvenile mice (4-6 wk old) but attenuated in mature mice (>3 mo old). Interestingly, allergen induction of the same asthmatic traits was less dependent on chronological age than viruses. Age-specific responses to SeV included a juvenile bias toward type 2 airway inflammation that emerged early in infection, whereas mature mice exhibited a more restricted bronchiolar distribution of infection that produced a distinct type 2 low inflammatory cytokine profile. In the basal state, aging produced changes to lung leukocyte burden, including the number and transcriptional landscape of alveolar macrophages (AMs). Importantly, depleting AMs in mature mice restored post-SeV pathology to juvenile levels. Thus, aging influences chronic outcomes of respiratory viral infection through regulation of the AM compartment and type 2 inflammatory responses to viruses. Our data provide insight into how asthma remission might develop in children.


Subject(s)
Age Factors , Aging/physiology , Asthma/immunology , COVID-19/immunology , Influenza A virus/physiology , Influenza, Human/immunology , Lung/immunology , Orthomyxoviridae Infections/immunology , Respirovirus Infections/immunology , SARS-CoV-2/physiology , Sendai virus/physiology , Th2 Cells/immunology , Animals , Asthma/epidemiology , COVID-19/epidemiology , Cytokines/metabolism , Humans , Influenza, Human/epidemiology , Mice , Mice, Inbred C57BL , United States/epidemiology
9.
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
12.
Biomed Pharmacother ; 147: 112614, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1682939

ABSTRACT

Post-Covid pulmonary fibrosis is evident following severe COVID-19. There is an urgent need to identify the cellular and pathophysiological characteristics of chronic lung squeals of Covid-19 for the development of future preventive and/or therapeutic interventions. Tissue-resident memory T (TRM) cells can mediate local immune protection against infections and cancer. Less beneficially, lung TRM cells cause chronic airway inflammation and fibrosis by stimulating pathologic inflammation. The effects of Janus kinase (JAK), an inducer pathway of cytokine storm, inhibition on acute Covid-19 cases have been previously evaluated. Here, we propose that Tofacitinib by targeting the CD8+ TRM cells could be a potential candidate for the treatment of chronic lung diseases induced by acute SARS-CoV-2 infection.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/drug therapy , Janus Kinase Inhibitors/therapeutic use , Lung Injury/drug therapy , Piperidines/therapeutic use , Pyrimidines/therapeutic use , T-Lymphocyte Subsets/immunology , COVID-19/complications , COVID-19/immunology , Humans , Immunologic Memory/immunology , Lung/immunology , Lung Injury/etiology , Lung Injury/immunology , SARS-CoV-2 , T-Lymphocytes/immunology
13.
Cell ; 185(4): 614-629.e21, 2022 02 17.
Article in English | MEDLINE | ID: covidwho-1676664

ABSTRACT

Activation of the innate immune system via pattern recognition receptors (PRRs) is key to generate lasting adaptive immunity. PRRs detect unique chemical patterns associated with invading microorganisms, but whether and how the physical properties of PRR ligands influence the development of the immune response remains unknown. Through the study of fungal mannans, we show that the physical form of PRR ligands dictates the immune response. Soluble mannans are immunosilent in the periphery but elicit a potent pro-inflammatory response in the draining lymph node (dLN). By modulating the physical form of mannans, we developed a formulation that targets both the periphery and the dLN. When combined with viral glycoprotein antigens, this mannan formulation broadens epitope recognition, elicits potent antigen-specific neutralizing antibodies, and confers protection against viral infections of the lung. Thus, the physical properties of microbial ligands determine the outcome of the immune response and can be harnessed for vaccine development.


Subject(s)
Adjuvants, Immunologic/pharmacology , Antigens, Viral/immunology , Candida albicans/chemistry , Mannans/immunology , Aluminum Hydroxide/chemistry , Animals , Antibodies, Neutralizing/immunology , Antibody Specificity/immunology , B-Lymphocytes/immunology , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , Chlorocebus aethiops , Epitopes/immunology , Immunity, Innate , Immunization , Inflammation/pathology , Interferons/metabolism , Lectins, C-Type/metabolism , Ligands , Lung/immunology , Lung/pathology , Lung/virology , Lymph Nodes/immunology , Lymph Nodes/metabolism , Macrophages/metabolism , Mice, Inbred C57BL , Paranasal Sinuses/metabolism , Protein Subunits/metabolism , Sialic Acid Binding Ig-like Lectin 1/metabolism , Solubility , Spike Glycoprotein, Coronavirus/metabolism , T-Lymphocytes/immunology , Transcription Factor RelB/metabolism , Vero Cells , beta-Glucans/metabolism
14.
Sci Immunol ; 7(67): eabl9929, 2022 Jan 28.
Article in English | MEDLINE | ID: covidwho-1673341

ABSTRACT

The development of a tractable small animal model faithfully reproducing human coronavirus disease 2019 pathogenesis would arguably meet a pressing need in biomedical research. Thus far, most investigators have used transgenic mice expressing the human ACE2 in epithelial cells (K18-hACE2 transgenic mice) that are intranasally instilled with a liquid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) suspension under deep anesthesia. Unfortunately, this experimental approach results in disproportionate high central nervous system infection leading to fatal encephalitis, which is rarely observed in humans and severely limits this model's usefulness. Here, we describe the use of an inhalation tower system that allows exposure of unanesthetized mice to aerosolized virus under controlled conditions. Aerosol exposure of K18-hACE2 transgenic mice to SARS-CoV-2 resulted in robust viral replication in the respiratory tract, anosmia, and airway obstruction but did not lead to fatal viral neuroinvasion. When compared with intranasal inoculation, aerosol infection resulted in a more pronounced lung pathology including increased immune infiltration, fibrin deposition, and a transcriptional signature comparable to that observed in SARS-CoV-2­infected patients. This model may prove useful for studies of viral transmission, disease pathogenesis (including long-term consequences of SARS-CoV-2 infection), and therapeutic interventions.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/physiopathology , Disease Models, Animal , Encephalitis, Viral/prevention & control , Keratin-18/genetics , Nasal Sprays , SARS-CoV-2/physiology , Administration, Inhalation , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/immunology , COVID-19/virology , Encephalitis, Viral/mortality , Epithelial Cells/metabolism , Female , Humans , Keratin-18/metabolism , Lung/immunology , Lung/pathology , Lung/physiopathology , Male , Mice , Mice, Transgenic , Promoter Regions, Genetic/genetics , Transcriptome , Virus Replication
15.
Viruses ; 14(2)2022 02 06.
Article in English | MEDLINE | ID: covidwho-1674825

ABSTRACT

SARS-CoV-2-specific CD8+ T cell immunity is expected to counteract viral variants in both efficient and durable ways. We recently described a way to induce a potent SARS-CoV-2 CD8+ T immune response through the generation of engineered extracellular vesicles (EVs) emerging from muscle cells. This method relies on intramuscular injection of DNA vectors expressing different SARS-CoV-2 antigens fused at their N-terminus with the Nefmut protein, i.e., a very efficient EV-anchoring protein. However, quality, tissue distribution, and efficacy of these SARS-CoV-2-specific CD8+ T cells remained uninvestigated. To fill the gaps, antigen-specific CD8+ T lymphocytes induced by the immunization through the Nefmut-based method were characterized in terms of their polyfunctionality and localization at lung airways, i.e., the primary targets of SARS-CoV-2 infection. We found that injection of vectors expressing Nefmut/S1 and Nefmut/N generated polyfunctional CD8+ T lymphocytes in both spleens and bronchoalveolar lavage fluids (BALFs). When immunized mice were infected with 4.4 lethal doses of 50% of SARS-CoV-2, all S1-immunized mice succumbed, whereas those developing the highest percentages of N-specific CD8+ T lymphocytes resisted the lethal challenge. We also provide evidence that the N-specific immunization coupled with the development of antigen-specific CD8+ T-resident memory cells in lungs, supporting the idea that the Nefmut-based immunization can confer a long-lasting, lung-specific immune memory. In view of the limitations of current anti-SARS-CoV-2 vaccines in terms of antibody waning and efficiency against variants, our CD8+ T cell-based platform could be considered for a new combination prophylactic strategy.


Subject(s)
Antigens, Viral/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/prevention & control , Extracellular Vesicles/immunology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , Antigens, Viral/administration & dosage , Antigens, Viral/genetics , COVID-19/immunology , Female , Genetic Vectors/administration & dosage , Genetic Vectors/immunology , Humans , Lung/immunology , Lung/virology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Vaccination
16.
Int J Mol Sci ; 23(3)2022 Feb 02.
Article in English | MEDLINE | ID: covidwho-1674667

ABSTRACT

Mast cells (MCs) have relevant participation in inflammatory and vascular hyperpermeability events, responsible for the action of the kallikrein-kinin system (KKS), that affect patients inflicted by the severe form of COVID-19. Given a higher number of activated MCs present in COVID-19 patients and their association with vascular hyperpermeability events, we investigated the factors that lead to the activation and degranulation of these cells and their harmful effects on the alveolar septum environment provided by the action of its mediators. Therefore, the pyroptotic processes throughout caspase-1 (CASP-1) and alarmin interleukin-33 (IL-33) secretion were investigated, along with the immunoexpression of angiotensin-converting enzyme 2 (ACE2), bradykinin receptor B1 (B1R) and bradykinin receptor B2 (B2R) on post-mortem lung samples from 24 patients affected by COVID-19. The results were compared to 10 patients affected by H1N1pdm09 and 11 control patients. As a result of the inflammatory processes induced by SARS-CoV-2, the activation by immunoglobulin E (IgE) and degranulation of tryptase, as well as Toluidine Blue metachromatic (TB)-stained MCs of the interstitial and perivascular regions of the same groups were also counted. An increased immunoexpression of the tissue biomarkers CASP-1, IL-33, ACE2, B1R and B2R was observed in the alveolar septum of the COVID-19 patients, associated with a higher density of IgE+ MCs, tryptase+ MCs and TB-stained MCs, in addition to the presence of intra-alveolar edema. These findings suggest the direct correlation of MCs with vascular hyperpermeability, edema and diffuse alveolar damage (DAD) events that affect patients with a severe form of this disease. The role of KKS activation in events involving the exacerbated increase in vascular permeability and its direct link with the conditions that precede intra-alveolar edema, and the consequent DAD, is evidenced. Therapy with drugs that inhibit the activation/degranulation of MCs can prevent the worsening of the prognosis and provide a better outcome for the patient.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , Capillary Permeability , Kallikrein-Kinin System/physiology , Lung/pathology , Mast Cells/immunology , SARS-CoV-2/immunology , Adult , Aged , Autopsy , COVID-19/immunology , COVID-19/virology , Caspase 1/metabolism , Female , Humans , Interleukin-33/metabolism , Lung/immunology , Lung/metabolism , Lung/virology , Male , Mast Cells/metabolism , Mast Cells/virology , Middle Aged , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity
17.
Nat Commun ; 13(1): 679, 2022 02 03.
Article in English | MEDLINE | ID: covidwho-1671560

ABSTRACT

Emergence of mutant SARS-CoV-2 strains associated with an increased risk of COVID-19-related death necessitates better understanding of the early viral dynamics, host responses and immunopathology. Single cell RNAseq (scRNAseq) allows for the study of individual cells, uncovering heterogeneous and variable responses to environment, infection and inflammation. While studies have reported immune profiling using scRNAseq in terminal human COVID-19 patients, performing longitudinal immune cell dynamics in humans is challenging. Macaques are a suitable model of SARS-CoV-2 infection. Our longitudinal scRNAseq of bronchoalveolar lavage (BAL) cell suspensions from young rhesus macaques infected with SARS-CoV-2 (n = 6) demonstrates dynamic changes in transcriptional landscape 3 days post- SARS-CoV-2-infection (3dpi; peak viremia), relative to 14-17dpi (recovery phase) and pre-infection (baseline) showing accumulation of distinct populations of both macrophages and T-lymphocytes expressing strong interferon-driven inflammatory gene signature at 3dpi. Type I interferon response is induced in the plasmacytoid dendritic cells with appearance of a distinct HLADR+CD68+CD163+SIGLEC1+ macrophage population exhibiting higher angiotensin-converting enzyme 2 (ACE2) expression. These macrophages are significantly enriched in the lungs of macaques at 3dpi and harbor SARS-CoV-2 while expressing a strong interferon-driven innate anti-viral gene signature. The accumulation of these responses correlated with decline in viremia and recovery.


Subject(s)
COVID-19/immunology , Interferons/pharmacology , Myeloid Cells/immunology , SARS-CoV-2/drug effects , Animals , Antiviral Agents , Bronchoalveolar Lavage , Disease Models, Animal , Humans , Immunity, Innate , Inflammation , Interferon Type I/genetics , Interferon Type I/pharmacology , Interferons/genetics , Lung/immunology , Lung/pathology , Macaca mulatta , Macrophages/immunology , T-Lymphocytes/immunology
18.
Front Immunol ; 12: 780900, 2021.
Article in English | MEDLINE | ID: covidwho-1662580

ABSTRACT

Mesenchymal stem cells (MSCs) are multipotent adult stem cells present in virtually all tissues; they have potent self-renewal capacity and differentiate into multiple cell types. For many reasons, these cells are a promising therapeutic alternative to treat patients with severe COVID-19 and pulmonary post-COVID sequelae. These cells are not only essential for tissue regeneration; they can also alter the pulmonary environment through the paracrine secretion of several mediators. They can control or promote inflammation, induce other stem cells differentiation, restrain the virus load, and much more. In this work, we performed single-cell RNA-seq data analysis of MSCs in bronchoalveolar lavage samples from control individuals and COVID-19 patients with mild and severe clinical conditions. When we compared samples from mild cases with control individuals, most genes transcriptionally upregulated in COVID-19 were involved in cell proliferation. However, a new set of genes with distinct biological functions was upregulated when we compared severely affected with mild COVID-19 patients. In this analysis, the cells upregulated genes related to cell dispersion/migration and induced the γ-activated sequence (GAS) genes, probably triggered by IFNGR1 and IFNGR2. Then, IRF-1 was upregulated, one of the GAS target genes, leading to the interferon-stimulated response (ISR) and the overexpression of many signature target genes. The MSCs also upregulated genes involved in the mesenchymal-epithelial transition, virus control, cell chemotaxis, and used the cytoplasmic RNA danger sensors RIG-1, MDA5, and PKR. In a non-comparative analysis, we observed that MSCs from severe cases do not express many NF-κB upstream receptors, such as Toll-like (TLRs) TLR-3, -7, and -8; tumor necrosis factor (TNFR1 or TNFR2), RANK, CD40, and IL-1R1. Indeed, many NF-κB inhibitors were upregulated, including PPP2CB, OPTN, NFKBIA, and FHL2, suggesting that MSCs do not play a role in the "cytokine storm" observed. Therefore, lung MSCs in COVID-19 sense immune danger and act protectively in concert with the pulmonary environment, confirming their therapeutic potential in cell-based therapy for COVID-19. The transcription of MSCs senescence markers is discussed.


Subject(s)
COVID-19/immunology , Cell Proliferation/physiology , Inflammation/immunology , Lung/immunology , Mesenchymal Stem Cells/immunology , Regeneration/immunology , Adult , COVID-19/metabolism , Cell Differentiation/immunology , Cell Movement/immunology , Cytoplasm/immunology , Epithelial-Mesenchymal Transition/immunology , Humans , Inflammation/metabolism , Mesenchymal Stem Cells/metabolism , SARS-CoV-2/immunology , Up-Regulation/immunology , Young Adult
20.
Cell Rep ; 38(7): 110387, 2022 02 15.
Article in English | MEDLINE | ID: covidwho-1654154

ABSTRACT

SARS-CoV-2 variants of concern (VOCs) display enhanced transmissibility and resistance to antibody neutralization. Comparing the early 2020 isolate EU-1 to the VOCs Alpha, Beta, and Gamma in mice transgenic for human ACE2 reveals that VOCs induce a broadened scope of symptoms, expand systemic infection to the gastrointestinal tract, elicit the depletion of natural killer cells, and trigger variant-specific cytokine production patterns. Gamma infections result in accelerated disease progression associated with increased immune activation and inflammation. All four SARS-CoV-2 variants induce pDC depletion in the lungs, paralleled by reduced interferon responses. Remarkably, VOCs also use the murine ACE2 receptor for infection to replicate in the lungs of wild-type animals, which induce cellular and innate immune responses that apparently curtail the spread of overt disease. VOCs thus display distinct intrinsic pathogenic properties with broadened tissue and host range. The enhanced pathogenicity of VOCs and their potential for reverse zoonotic transmission pose challenges to clinical and pandemic management.


Subject(s)
COVID-19/virology , Disease Models, Animal , SARS-CoV-2/physiology , SARS-CoV-2/pathogenicity , Animals , COVID-19/immunology , Cytokines/metabolism , Host Specificity , Immunity, Cellular , Immunity, Innate , Lung/immunology , Lung/virology , Mice , Species Specificity , Viral Load , Viral Tropism , Virulence , Virus Replication
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