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1.
Front Immunol ; 12: 763098, 2021.
Article in English | MEDLINE | ID: covidwho-1581339

ABSTRACT

Although initial immunophenotypical studies on peripheral blood and bronchoalveolar lavage samples have provided a glimpse into the immunopathology of COVID-19, analyses of pulmonary draining lymph nodes are currently scarce. 22 lethal COVID-19 cases and 28 controls were enrolled in this study. Pulmonary draining lymph nodes (mediastinal, tracheal, peribronchial) were collected at autopsy. Control lymph nodes were selected from a range of histomorphological sequelae [unremarkable histology, infectious mononucleosis, follicular hyperplasia, non-SARS related HLH, extrafollicular plasmablast activation, non-SARS related diffuse alveolar damage (DAD), pneumonia]. Samples were mounted on a tissue microarray and underwent immunohistochemical staining for a selection of immunological markers and in-situ hybridization for Epstein Barr Virus (EBV) and SARS-CoV-2. Gene expression profiling was performed using the HTG EdgeSeq Immune Response Panel. Characteristic patterns of a dysregulated immune response were detected in COVID-19: 1. An accumulation of extrafollicular plasmablasts with a relative paucity or depletion of germinal centers. 2. Evidence of T-cell dysregulation demonstrated by immunohistochemical paucity of FOXP3+, Tbet+ and LEF1+ positive T-cells and a downregulation of key genes responsible for T-cell crosstalk, maturation and migration as well as a reactivation of herpes viruses in 6 COVID-19 lymph nodes (EBV, HSV). 3. Macrophage activation by a M2-polarized, CD163+ phenotype and increased incidence of hemophagocytic activity. 4. Microvascular dysfunction, evidenced by an upregulation of hemostatic (CD36, PROCR, VWF) and proangiogenic (FLT1, TEK) genes and an increase of fibrin microthrombi and CD105+ microvessels. Taken together, these findings imply widespread dysregulation of both innate and adoptive pathways with concordant microvascular dysfunction in severe COVID-19.


Subject(s)
COVID-19/immunology , COVID-19/pathology , Lymph Nodes/immunology , Lymph Nodes/pathology , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Lung , Macrophage Activation/immunology , Male , Middle Aged , SARS-CoV-2 , T-Lymphocytes/immunology , T-Lymphocytes/pathology , /pathology , /virology
2.
Int J Mol Sci ; 22(22)2021 Nov 21.
Article in English | MEDLINE | ID: covidwho-1524028

ABSTRACT

Aging is characterized by the dynamic remodeling of the immune system designated "immunosenescence," and is associated with altered hematopoiesis, thymic involution, and lifelong immune stimulation by multitudinous chronic stressors, including the cytomegalovirus (CMV). Such alterations may contribute to a lowered proportion of naïve T-cells and to reduced diversity of the T-cell repertoire. In the peripheral circulation, a shift occurs towards accumulations of T and B-cell populations with memory phenotypes, and to accumulation of putatively senescent and exhausted immune cells. The aging-related accumulations of functionally exhausted memory T lymphocytes, commonly secreting pro-inflammatory cytokines, together with mediators and factors of the innate immune system, are considered to contribute to the low-grade inflammation (inflammaging) often observed in elderly people. These senescent immune cells not only secrete inflammatory mediators, but are also able to negatively modulate their environments. In this review, we give a short summary of the ways that immunosenescence, inflammaging, and CMV infection may cause insufficient immune responses, contribute to the establishment of the hyperinflammatory syndrome and impact the severity of the coronavirus disease 2019 (COVID-19) in elderly people.


Subject(s)
COVID-19/pathology , Aging , B-Lymphocytes/pathology , COVID-19/complications , COVID-19/virology , Cytokine Release Syndrome/complications , Cytokine Release Syndrome/pathology , Cytomegalovirus/isolation & purification , Cytomegalovirus Infections/pathology , Cytomegalovirus Infections/virology , Humans , SARS-CoV-2/isolation & purification , T-Lymphocytes/pathology
3.
Int J Mol Sci ; 22(21)2021 Oct 30.
Article in English | MEDLINE | ID: covidwho-1512378

ABSTRACT

Autoimmune epithelitis and chronic inflammation are one of the characteristic features of the immune pathogenesis of Sjögren's syndrome (SS)-related dry eye disease. Autoimmune epithelitis can cause the dysfunction of the excretion of tear fluid and mucin from the lacrimal glands and conjunctival epithelia and meibum from the meibomian glands. The lacrimal gland and conjunctival epithelia express major histocompatibility complex class II or human leukocyte antigen-DR and costimulatory molecules, acting as nonprofessional antigen-presenting cells for T cell and B cell activation in SS. Ocular surface epithelium dysfunction can lead to dry eye disease in SS. Considering the mechanisms underlying SS-related dry eye disease, this review highlights autoimmune epithelitis of the ocular surface, chronic inflammation, and several other molecules in the tear film, cornea, conjunctiva, lacrimal glands, and meibomian glands that represent potential targets in the treatment of SS-related dry eye disease.


Subject(s)
B-Lymphocytes/immunology , Conjunctiva/immunology , Lacrimal Apparatus/immunology , Lymphocyte Activation , Meibomian Glands/immunology , Sjogren's Syndrome/immunology , T-Lymphocytes/immunology , B-Lymphocytes/pathology , Chronic Disease , Conjunctiva/pathology , Humans , Lacrimal Apparatus/pathology , Meibomian Glands/pathology , Mucins/immunology , Sjogren's Syndrome/pathology , T-Lymphocytes/pathology
4.
J Infect Dis ; 224(8): 1333-1344, 2021 10 28.
Article in English | MEDLINE | ID: covidwho-1493827

ABSTRACT

BACKGROUND: Lymphopenia is a key feature for adult patients with coronavirus disease 2019 (COVID-19), although it is rarely observed in children. The underlying mechanism remains unclear. METHODS: Immunohistochemical and flow cytometric analyses were used to compare the apoptotic rate of T cells from COVID-19 adults and children and apoptotic responses of adult and child T cells to COVID-19 pooled plasma. Biological properties of caspases and reactive oxygen species were assessed in T cells treated by COVID-19 pooled plasma. RESULTS: Mitochondria apoptosis of peripheral T cells were identified in COVID-19 adult patient samples but not in the children. Furthermore, increased tumor necrosis factor-α and interleukin-6 in COVID-19 plasma induced mitochondria apoptosis and caused deoxyribonucleic acid damage by elevating reactive oxygen species levels of the adult T cells. However, the child T cells showed tolerance to mitochondrial apoptosis due to mitochondria autophagy. Activation of autophagy could decrease apoptotic sensitivity of the adult T cells to plasma from COVID-19 patients. CONCLUSIONS: Our results indicated that the mitochondrial apoptosis pathway was activated in T cells of COVID-19 adult patients specifically, which may shed light on the pathophysiological difference between adults and children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 ).


Subject(s)
COVID-19/complications , Lymphopenia/blood , SARS-CoV-2/immunology , T-Lymphocytes/pathology , Adolescent , Adult , Age Factors , Aged , Apoptosis/immunology , Autophagy , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Child , Child, Preschool , Humans , Infant , Lymphopenia/immunology , Lymphopenia/pathology , Lymphopenia/virology , Male , Middle Aged , Mitochondria/immunology , Mitochondria/pathology , Reactive Oxygen Species/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/immunology
5.
Pathol Res Pract ; 225: 153552, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1440296

ABSTRACT

BACKGROUND: Pulmonary arterial hypertension (PAH) is characterized by severe vascular remodelling, resulting in increased pulmonary vascular resistance with cardiac hypertrophy and heart failure. However, the diagnosis of PAH is often inaccurate. Many cases of PAH are incorrectly diagnosed or missed, and they are often associated with death. The aim of this study was to verify the morphological and histological criteria of fatal cases of PAH and evaluate the lymphocytic populations associated to lesions with reactive neo-angiogenesis. METHODS: Pulmonary lung sections from 10 cases of sudden unexpected death (SUD) in the absence of previously diagnosed diseases and in an apparent state of well-being, with final histological post autopsy diagnosis of PAH were collected. The pathological findings were compared using ten controls from non-pathological lung from deaths from other causes. The autopsies included 4 males (40%) and 6 females (60%) with an average age of 52.1 ± 10.1 years. Sections stained with hematoxylin and eosin (H&E) were revised for a morphological diagnosis. Subsequently, serial sections were performed and stained with immunohistochemistry for anti-CD20 (B-lymphocytes), anti-CD3 (T-lymphocytes), anti-CD4 (T-helper lumphocytes), anti-CD8 (T-cytotoxic lymphocytes) and anti-CD117/C-Kit (mast cells/MCs) to detect inflammatory infiltrate and different ratios of cell-type. Statistical analysis was conducted using a paired t-test looking at 100 cells in 3 different tissue samples representative of vascular lesion and 3 different random normal lung parenchyma fields without lesion (from 10 normal control lungs), to identify specific lymphocyte subpopulations in inflammatory infiltrates. RESULTS: There was a significant percentage increase of CD20 (p < 0.001), CD8 (p = 0.002), CD4 (p < 0.001), and CD117/C-Kit positive (C-Kit+; p < 0.001) cells mainly detected around wall vessels; while increased MCs positivity and C-Kit+ were observed especially in alveolar septa. In addition, reactive angiomatosis was observed. CONCLUSIONS: The inflammatory infiltrate should be included for a correct diagnosis of PAH besides the vascular remodelling. The inflammatory infiltrate seems to be implicated as a main factor in the pathogenesis. This finding is important to rule out secondary pulmonary hypertension, to identify SUDs of unknown causes and to add new elements to the literature that can explain the immunologically related pathogenesis of PAH.


Subject(s)
B-Lymphocytes/pathology , Lung/pathology , Mast Cells/pathology , Pulmonary Arterial Hypertension/pathology , T-Lymphocytes/pathology , Adult , Autopsy , Female , Humans , Male , Middle Aged
6.
J Infect Dis ; 224(8): 1333-1344, 2021 10 28.
Article in English | MEDLINE | ID: covidwho-1349787

ABSTRACT

BACKGROUND: Lymphopenia is a key feature for adult patients with coronavirus disease 2019 (COVID-19), although it is rarely observed in children. The underlying mechanism remains unclear. METHODS: Immunohistochemical and flow cytometric analyses were used to compare the apoptotic rate of T cells from COVID-19 adults and children and apoptotic responses of adult and child T cells to COVID-19 pooled plasma. Biological properties of caspases and reactive oxygen species were assessed in T cells treated by COVID-19 pooled plasma. RESULTS: Mitochondria apoptosis of peripheral T cells were identified in COVID-19 adult patient samples but not in the children. Furthermore, increased tumor necrosis factor-α and interleukin-6 in COVID-19 plasma induced mitochondria apoptosis and caused deoxyribonucleic acid damage by elevating reactive oxygen species levels of the adult T cells. However, the child T cells showed tolerance to mitochondrial apoptosis due to mitochondria autophagy. Activation of autophagy could decrease apoptotic sensitivity of the adult T cells to plasma from COVID-19 patients. CONCLUSIONS: Our results indicated that the mitochondrial apoptosis pathway was activated in T cells of COVID-19 adult patients specifically, which may shed light on the pathophysiological difference between adults and children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 ).


Subject(s)
COVID-19/complications , Lymphopenia/blood , SARS-CoV-2/immunology , T-Lymphocytes/pathology , Adolescent , Adult , Age Factors , Aged , Apoptosis/immunology , Autophagy , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Child , Child, Preschool , Humans , Infant , Lymphopenia/immunology , Lymphopenia/pathology , Lymphopenia/virology , Male , Middle Aged , Mitochondria/immunology , Mitochondria/pathology , Reactive Oxygen Species/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/immunology
7.
Cells ; 10(7)2021 07 19.
Article in English | MEDLINE | ID: covidwho-1323130

ABSTRACT

Since the end of 2019, a new, dangerous virus has caused the deaths of more than 3 million people. Efforts to fight the disease remain multifaceted and include prophylactic strategies (vaccines), the development of antiviral drugs targeting replication, and the mitigation of the damage associated with exacerbated immune responses (e.g., interleukin-6-receptor inhibitors). However, numerous uncertainties remain, making it difficult to lower the mortality rate, especially among critically ill patients. While looking for a new means of understanding the pathomechanisms of the disease, we asked a question-is our immunity key to resolving these uncertainties? In this review, we attempt to answer this question, and summarize, interpret, and discuss the available knowledge concerning the interplay between neutrophils, neutrophil extracellular traps (NETs), and T-cells in COVID-19. These are considered to be the first line of defense against pathogens and, thus, we chose to emphasize their role in SARS-CoV-2 infection. Although immunologic alterations are the subject of constant research, they are poorly understood and often underestimated. This review provides background information for the expansion of research on the novel, immunity-oriented approach to diagnostic and treatment possibilities.


Subject(s)
COVID-19/immunology , Extracellular Traps/immunology , Neutrophils/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Animals , COVID-19/diagnosis , COVID-19/pathology , COVID-19/therapy , Humans , Immunity, Innate , Neutrophils/pathology , T-Lymphocytes/pathology
8.
Nat Commun ; 12(1): 3501, 2021 06 09.
Article in English | MEDLINE | ID: covidwho-1263489

ABSTRACT

The characteristics of COVID-19 patients with persistent SARS-CoV-2 infection are not yet well described. Here, we compare the clinical and molecular features of patients with long duration of viral shedding (LDs) with those from patients with short duration patients (SDs), and healthy donors (HDs). We find that several cytokines and chemokines, such as interleukin (IL)-2, tumor necrosis factor (TNF) and lymphotoxin α (LT-α) are present at lower levels in LDs than SDs. Single-cell RNA sequencing shows that natural killer (NK) cells and CD14+ monocytes are reduced, while regulatory T cells are increased in LDs; moreover, T and NK cells in LDs are less activated than in SDs. Importantly, most cells in LDs show reduced expression of ribosomal protein (RP) genes and related pathways, with this inversed correlation between RP levels and infection duration further validated in 103 independent patients. Our results thus indicate that immunosuppression and low RP expression may be related to the persistence of the viral infection in COVID-19 patients.


Subject(s)
COVID-19/immunology , SARS-CoV-2/pathogenicity , B-Lymphocytes/metabolism , B-Lymphocytes/pathology , COVID-19/virology , Cytokines/blood , Gene Expression Profiling , Humans , Killer Cells, Natural/metabolism , Killer Cells, Natural/pathology , Leukocytes, Mononuclear/pathology , Lymphocyte Activation/genetics , Lymphocyte Subsets/metabolism , Lymphocyte Subsets/pathology , Ribosomal Proteins/genetics , SARS-CoV-2/isolation & purification , Signal Transduction/genetics , T-Lymphocytes/metabolism , T-Lymphocytes/pathology , Virus Shedding
9.
Brain ; 144(9): 2696-2708, 2021 10 22.
Article in English | MEDLINE | ID: covidwho-1185655

ABSTRACT

Many patients with SARS-CoV-2 infection develop neurological signs and symptoms; although, to date, little evidence exists that primary infection of the brain is a significant contributing factor. We present the clinical, neuropathological and molecular findings of 41 consecutive patients with SARS-CoV-2 infections who died and underwent autopsy in our medical centre. The mean age was 74 years (38-97 years), 27 patients (66%) were male and 34 (83%) were of Hispanic/Latinx ethnicity. Twenty-four patients (59%) were admitted to the intensive care unit. Hospital-associated complications were common, including eight patients (20%) with deep vein thrombosis/pulmonary embolism, seven (17%) with acute kidney injury requiring dialysis and 10 (24%) with positive blood cultures during admission. Eight (20%) patients died within 24 h of hospital admission, while 11 (27%) died more than 4 weeks after hospital admission. Neuropathological examination of 20-30 areas from each brain revealed hypoxic/ischaemic changes in all brains, both global and focal; large and small infarcts, many of which appeared haemorrhagic; and microglial activation with microglial nodules accompanied by neuronophagia, most prominently in the brainstem. We observed sparse T lymphocyte accumulation in either perivascular regions or in the brain parenchyma. Many brains contained atherosclerosis of large arteries and arteriolosclerosis, although none showed evidence of vasculitis. Eighteen patients (44%) exhibited pathologies of neurodegenerative diseases, which was not unexpected given the age range of our patients. We examined multiple fresh frozen and fixed tissues from 28 brains for the presence of viral RNA and protein, using quantitative reverse-transcriptase PCR, RNAscope® and immunocytochemistry with primers, probes and antibodies directed against the spike and nucleocapsid regions. The PCR analysis revealed low to very low, but detectable, viral RNA levels in the majority of brains, although they were far lower than those in the nasal epithelia. RNAscope® and immunocytochemistry failed to detect viral RNA or protein in brains. Our findings indicate that the levels of detectable virus in coronavirus disease 2019 brains are very low and do not correlate with the histopathological alterations. These findings suggest that microglial activation, microglial nodules and neuronophagia, observed in the majority of brains, do not result from direct viral infection of brain parenchyma, but more likely from systemic inflammation, perhaps with synergistic contribution from hypoxia/ischaemia. Further studies are needed to define whether these pathologies, if present in patients who survive coronavirus disease 2019, might contribute to chronic neurological problems.


Subject(s)
Brain Infarction/pathology , Brain/pathology , COVID-19/pathology , Hypoxia-Ischemia, Brain/pathology , Intracranial Hemorrhages/pathology , Acute Kidney Injury/complications , Acute Kidney Injury/physiopathology , Acute Kidney Injury/therapy , Adult , Aged , Aged, 80 and over , Bacteremia/complications , Brain/metabolism , Brain Infarction/complications , COVID-19/complications , COVID-19/physiopathology , Coronavirus Nucleocapsid Proteins/metabolism , Female , Humans , Hypoxia-Ischemia, Brain/complications , Inflammation , Intensive Care Units , Intracranial Hemorrhages/complications , Male , Microglia/pathology , Middle Aged , Neurons/pathology , Phagocytosis , Phosphoproteins/metabolism , Pulmonary Embolism/complications , Pulmonary Embolism/physiopathology , RNA, Viral/metabolism , Renal Dialysis , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/metabolism , Survival Rate , T-Lymphocytes/pathology , Venous Thrombosis/complications , Venous Thrombosis/physiopathology
10.
Life Sci ; 277: 119503, 2021 Jul 15.
Article in English | MEDLINE | ID: covidwho-1185151

ABSTRACT

Severe coronavirus disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is characterized by an unpredictable disease course, with variable presentations of different organ systems. The clinical manifestations of COVID-19 are highly variable ranging from mild presentations to severe, life-threatening symptoms and the wide individual variability may be due to the broad heterogeneity in the underlying pathologies. There is no doubt that early management may have a major influence on the outcome. This led the scientists to search for ways to monitor disease progression or to predict outcomes in COVID-19. Although it is not yet possible to predict who will progress to the severe forms or in what time, numerous prospective and longitudinal studies represent the evidence for determining the potential immunological risk factors of COVID-19 critical disease and death. The kinetics and breadth of immune responses during COVID-19 appear to follow a trend which is consistent to the predominant pathological alterations. Recent publications have used these biomarkers to help identify patients who will develop the severe acute COVID-19. Of particular interest is the relationship between the kinetics of peripheral leukocytes and clinical progress of the disease in COVID-19. Although research is ongoing in this area, we present details about the current status of the evaluation. Understanding of the COVID-19 related alterations of the innate and adaptive immune responses may help to promote the vaccine development and immunological interventions.


Subject(s)
COVID-19/immunology , Leukocytes/immunology , SARS-CoV-2/immunology , COVID-19/etiology , COVID-19/pathology , COVID-19/therapy , Disease Progression , Humans , Immunity, Cellular , Immunity, Innate , Immunotherapy , Leukocyte Count , Leukocytes/pathology , Macrophages/immunology , Macrophages/pathology , Risk Factors , SARS-CoV-2/isolation & purification , T-Lymphocytes/immunology , T-Lymphocytes/pathology
11.
Immunity ; 54(4): 797-814.e6, 2021 04 13.
Article in English | MEDLINE | ID: covidwho-1149231

ABSTRACT

Immune response dynamics in coronavirus disease 2019 (COVID-19) and their severe manifestations have largely been studied in circulation. Here, we examined the relationship between immune processes in the respiratory tract and circulation through longitudinal phenotypic, transcriptomic, and cytokine profiling of paired airway and blood samples from patients with severe COVID-19 relative to heathy controls. In COVID-19 airways, T cells exhibited activated, tissue-resident, and protective profiles; higher T cell frequencies correlated with survival and younger age. Myeloid cells in COVID-19 airways featured hyperinflammatory signatures, and higher frequencies of these cells correlated with mortality and older age. In COVID-19 blood, aberrant CD163+ monocytes predominated over conventional monocytes, and were found in corresponding airway samples and in damaged alveoli. High levels of myeloid chemoattractants in airways suggest recruitment of these cells through a CCL2-CCR2 chemokine axis. Our findings provide insights into immune processes driving COVID-19 lung pathology with therapeutic implications for targeting inflammation in the respiratory tract.


Subject(s)
COVID-19/immunology , Lung/immunology , Myeloid Cells/immunology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , COVID-19/blood , COVID-19/mortality , COVID-19/pathology , Cytokines/immunology , Cytokines/metabolism , Humans , Inflammation , Longitudinal Studies , Lung/pathology , Macrophages/immunology , Macrophages/pathology , Middle Aged , Monocytes/immunology , Monocytes/pathology , Myeloid Cells/pathology , SARS-CoV-2 , T-Lymphocytes/immunology , T-Lymphocytes/pathology , Transcriptome , Young Adult
12.
Int J Antimicrob Agents ; 56(4): 106129, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-1121213

ABSTRACT

INTRODUCTION: The effect of anti-infective agents in COVID-19 is unclear. The impact of changes in practice on prognosis over time has not been evaluated. METHODS: Single center, retrospective study in adults hospitalized in a medicine ward for COVID-19 from March 5th to April 25th 2020. Patient characteristics were compared between two periods (before/after March 19th) considering French guidelines. The aim of the study was to evaluate how medical care impacted unfavorable outcome, namely admission to intensive care unit (ICU) and/or death. RESULTS: A total of 132 patients were admitted: mean age 59.0±16.3 years; mean C-reactive protein (CRP) level 84.0±71.1 mg/L; 46% had a lymphocyte count <1000/mm3. Prescribed anti-infective agents were lopinavir-ritonavir (n=12), azithromycin (AZI) (n=28) and AZI combined with hydroxychloroquine (HCQ) (n=52). There was a significant decrease in ICU admission, from 43% to 12%, between the two periods (P<0.0001). Delays until transfer to ICU were similar between periods (P=0.86). Pulmonary computerized tomography (CT)-scans were performed significantly more often with time (from 50% to 90%, P<0.0001), and oxygen-dependency (53% vs 80%, P=0.001) and prescription of AZI±HCQ (from 25% to 76%, P<0.0001) were also greater over time. Multivariate analyses showed a reduction of unfavorable outcome in patients receiving AZI±HCQ (hazard ratio [HR]=0.45, 95% confidence interval [CI: 0.21-0.97], P=0.04), particularly among an identified category of individuals (lymphocyte ≥1000/mm3 or CRP ≥100 mg/L). CONCLUSION: The present study showed a significant decrease in admission to ICU over time, which was probably related to multiple factors, including a better indication of pulmonary CT-scan, oxygen therapy, and a suitable prescription of anti-infective agents.


Subject(s)
Anti-Infective Agents/therapeutic use , Azithromycin/therapeutic use , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Hydroxychloroquine/therapeutic use , Lopinavir/therapeutic use , Pneumonia, Viral/drug therapy , Ritonavir/therapeutic use , Adult , Aged , Betacoronavirus/pathogenicity , C-Reactive Protein/metabolism , COVID-19 , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/mortality , Coronavirus Infections/pathology , Disease Progression , Drug Combinations , Female , Humans , Intensive Care Units , Male , Middle Aged , Multivariate Analysis , Pandemics , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/mortality , Pneumonia, Viral/pathology , Prognosis , Retrospective Studies , SARS-CoV-2 , Survival Analysis , T-Lymphocytes/pathology , T-Lymphocytes/virology , Tomography, X-Ray Computed , Treatment Outcome
13.
Innate Immun ; 27(3): 240-250, 2021 04.
Article in English | MEDLINE | ID: covidwho-1109949

ABSTRACT

Cell destruction results in plasma accumulation of cell-free DNA (cfDNA). Dynamic changes in circulating lymphocytes are features of COVID-19. We aimed to investigate if cfDNA level can serve in stratification of COVID-19 patients, and if cfDNA level is associated with alterations in lymphocyte subsets and neutrophil-to-lymphocyte ratio (NLR). This cross-sectional comparative study enrolled 64 SARS-CoV-2-positive patients. Patients were subdivided to severe and non-severe groups. Plasma cfDNA concentration was determined by real-time quantitative PCR. Lymphocyte subsets were assessed by flow cytometry. There was significant increase in cfDNA among severe cases when compared with non-severe cases. cfDNA showed positive correlation with NLR and inverse correlation with T cell percentage. cfDNA positively correlated with ferritin and C-reactive protein. The output data of performed ROC curves to differentiate severe from non-severe cases revealed that cfDNA at cut-off ≥17.31 ng/µl and AUC of 0.96 yielded (93%) sensitivity and (73%) specificity. In summary, excessive release of cfDNA can serve as sensitive COVID-19 severity predictor. There is an association between cfDNA up-regulation and NLR up-regulation and T cell percentage down-regulation. cfDNA level can be used in stratification and personalized monitoring strategies in COVID-19 patients.


Subject(s)
COVID-19/diagnosis , COVID-19/immunology , DNA/blood , Lymphocyte Subsets/pathology , Lymphocytes/pathology , Neutrophils/pathology , Adult , Aged , C-Reactive Protein/analysis , COVID-19/blood , Cross-Sectional Studies , Diagnosis, Differential , Female , Ferritins/blood , Humans , Lymphocyte Count , Male , Middle Aged , Predictive Value of Tests , Prognosis , ROC Curve , Sensitivity and Specificity , T-Lymphocytes/pathology , Young Adult
14.
J Virol ; 95(9)2021 04 12.
Article in English | MEDLINE | ID: covidwho-1102152

ABSTRACT

Current influenza vaccines, live attenuated or inactivated, do not protect against antigenically novel influenza A viruses (IAVs) of pandemic potential, which has driven interest in the development of universal influenza vaccines. Universal influenza vaccine candidates targeting highly conserved antigens of IAV nucleoprotein (NP) are promising as vaccines that induce T cell immunity, but concerns have been raised about the safety of inducing robust CD8 T cell responses in the lungs. Using a mouse model, we systematically evaluated effects of recombinant adenovirus vectors (rAd) expressing IAV NP (A/NP-rAd) or influenza B virus (IBV) NP (B/NP-rAd) on pulmonary inflammation and function after vaccination and following live IAV challenge. After A/NP-rAd or B/NP-rAd vaccination, female mice exhibited robust systemic and pulmonary vaccine-specific B cell and T cell responses and experienced no morbidity (e.g., body mass loss). Both in vivo pulmonary function testing and lung histopathology scoring revealed minimal adverse effects of intranasal rAd vaccination compared with unvaccinated mice. After IAV challenge, A/NP-rAd-vaccinated mice experienced significantly less morbidity, had lower pulmonary virus titers, and developed less pulmonary inflammation than unvaccinated or B/NP-rAd-vaccinated mice. Based on analysis of pulmonary physiology using detailed testing not previously applied to the question of T cell damage, mice protected by vaccination also had better lung function than controls. Results provide evidence that, in this model, adenoviral universal influenza vaccine does not damage pulmonary tissue. In addition, adaptive immunity, in particular, T cell immunity in the lungs, does not cause damage when restimulated but instead mitigates pulmonary damage following IAV infection.IMPORTANCE Respiratory viruses can emerge and spread rapidly before vaccines are available. It would be a tremendous advance to use vaccines that protect against whole categories of viruses, such as universal influenza vaccines, without the need to predict which virus will emerge. The nucleoprotein (NP) of influenza virus provides a target conserved among strains and is a dominant T cell target. In animals, vaccination to NP generates powerful T cell immunity and long-lasting protection against diverse influenza strains. Concerns have been raised, but not evaluated experimentally, that potent local T cell responses might damage the lungs. We analyzed lung function in detail in the setting of such a vaccination. Despite CD8 T cell responses in the lungs, lungs were not damaged and functioned normally after vaccination alone and were protected upon subsequent infection. This precedent provides important support for vaccines based on T cell-mediated protection, currently being considered for both influenza and SARS-CoV-2 vaccines.


Subject(s)
Adenoviridae , Genetic Vectors , Influenza B virus , Influenza Vaccines , Lung , Orthomyxoviridae Infections , Adenoviridae/genetics , Adenoviridae/immunology , Animals , B-Lymphocytes/immunology , B-Lymphocytes/pathology , Disease Models, Animal , Female , Genetic Vectors/genetics , Genetic Vectors/immunology , Immunity, Cellular , Influenza B virus/genetics , Influenza B virus/immunology , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Lung/immunology , Lung/pathology , Lung/virology , Mice , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/prevention & control , T-Lymphocytes/immunology , T-Lymphocytes/pathology
15.
J Clin Invest ; 131(6)2021 03 15.
Article in English | MEDLINE | ID: covidwho-1045635

ABSTRACT

The immunopathology of coronavirus disease 2019 (COVID-19) remains enigmatic, causing immunodysregulation and T cell lymphopenia. Monocytic myeloid-derived suppressor cells (M-MDSCs) are T cell suppressors that expand in inflammatory conditions, but their role in acute respiratory infections remains unclear. We studied the blood and airways of patients with COVID-19 across disease severities at multiple time points. M-MDSC frequencies were elevated in blood but not in nasopharyngeal or endotracheal aspirates of patients with COVID-19 compared with healthy controls. M-MDSCs isolated from patients with COVID-19 suppressed T cell proliferation and IFN-γ production partly via an arginase 1-dependent (Arg-1-dependent) mechanism. Furthermore, patients showed increased Arg-1 and IL-6 plasma levels. Patients with COVID-19 had fewer T cells and downregulated expression of the CD3ζ chain. Ordinal regression showed that early M-MDSC frequency predicted subsequent disease severity. In conclusion, M-MDSCs expanded in the blood of patients with COVID-19, suppressed T cells, and were strongly associated with disease severity, indicating a role for M-MDSCs in the dysregulated COVID-19 immune response.


Subject(s)
COVID-19/immunology , Myeloid-Derived Suppressor Cells/immunology , Adult , Aged , Aged, 80 and over , Arginase/blood , COVID-19/blood , COVID-19/pathology , Case-Control Studies , Cohort Studies , Female , Humans , Influenza, Human/blood , Influenza, Human/immunology , Influenza, Human/pathology , Interferon-gamma/blood , Interleukin-6/blood , Leukocyte Count , Male , Middle Aged , Myeloid-Derived Suppressor Cells/pathology , Pandemics , Respiratory System/immunology , Respiratory System/pathology , SARS-CoV-2 , Severity of Illness Index , T-Lymphocytes/immunology , T-Lymphocytes/pathology , Young Adult
16.
PLoS One ; 16(1): e0245532, 2021.
Article in English | MEDLINE | ID: covidwho-1045570

ABSTRACT

BACKGROUND: Understanding the T cell response to SARS-CoV-2 is critical to vaccine development, epidemiological surveillance and disease control strategies. This systematic review critically evaluates and synthesises the relevant peer-reviewed and pre-print literature published from 01/01/2020-26/06/2020. METHODS: For this systematic review, keyword-structured literature searches were carried out in MEDLINE, Embase and COVID-19 Primer. Papers were independently screened by two researchers, with arbitration of disagreements by a third researcher. Data were independently extracted into a pre-designed Excel template and studies critically appraised using a modified version of the MetaQAT tool, with resolution of disagreements by consensus. Findings were narratively synthesised. RESULTS: 61 articles were included. 55 (90%) studies used observational designs, 50 (82%) involved hospitalised patients with higher acuity illness, and the majority had important limitations. Symptomatic adult COVID-19 cases consistently show peripheral T cell lymphopenia, which positively correlates with increased disease severity, duration of RNA positivity, and non-survival; while asymptomatic and paediatric cases display preserved counts. People with severe or critical disease generally develop more robust, virus-specific T cell responses. T cell memory and effector function has been demonstrated against multiple viral epitopes, and, cross-reactive T cell responses have been demonstrated in unexposed and uninfected adults, but the significance for protection and susceptibility, respectively, remains unclear. CONCLUSION: A complex pattern of T cell response to SARS-CoV-2 infection has been demonstrated, but inferences regarding population level immunity are hampered by significant methodological limitations and heterogeneity between studies, as well as a striking lack of research in asymptomatic or pauci-symptomatic individuals. In contrast to antibody responses, population-level surveillance of the T cell response is unlikely to be feasible in the near term. Focused evaluation in specific sub-groups, including vaccine recipients, should be prioritised.


Subject(s)
COVID-19/pathology , Lymphopenia/pathology , SARS-CoV-2/physiology , T-Lymphocytes/pathology , COVID-19/complications , COVID-19/immunology , COVID-19/virology , Host-Pathogen Interactions , Humans , Immunity, Cellular , Lymphopenia/etiology , Lymphopenia/immunology , Lymphopenia/virology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , T-Lymphocytes/virology
17.
J Clin Invest ; 131(1)2021 01 04.
Article in English | MEDLINE | ID: covidwho-1011051

ABSTRACT

SARS-CoV-2 causes a wide spectrum of clinical manifestations and significant mortality. Studies investigating underlying immune characteristics are needed to understand disease pathogenesis and inform vaccine design. In this study, we examined immune cell subsets in hospitalized and nonhospitalized individuals. In hospitalized patients, many adaptive and innate immune cells were decreased in frequency compared with those of healthy and convalescent individuals, with the exception of an increase in B lymphocytes. Our findings show increased frequencies of T cell activation markers (CD69, OX40, HLA-DR, and CD154) in hospitalized patients, with other T cell activation/exhaustion markers (PD-L1 and TIGIT) remaining elevated in hospitalized and nonhospitalized individuals. B cells had a similar pattern of activation/exhaustion, with increased frequency of CD69 and CD95 during hospitalization followed by an increase in PD1 frequencies in nonhospitalized individuals. Interestingly, many of these changes were found to increase over time in nonhospitalized longitudinal samples, suggesting a prolonged period of immune dysregulation after SARS-CoV-2 infection. Changes in T cell activation/exhaustion in nonhospitalized patients were found to positively correlate with age. Severely infected individuals had increased expression of activation and exhaustion markers. These data suggest a prolonged period of immune dysregulation after SARS-CoV-2 infection, highlighting the need for additional studies investigating immune dysregulation in convalescent individuals.


Subject(s)
Antigens, Differentiation/immunology , B-Lymphocytes/immunology , COVID-19/immunology , Lymphocyte Activation , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Adult , Aged , Aged, 80 and over , B-Lymphocytes/pathology , COVID-19/pathology , Female , Humans , Male , Middle Aged , T-Lymphocytes/pathology
18.
J Clin Invest ; 130(12): 6409-6416, 2020 12 01.
Article in English | MEDLINE | ID: covidwho-1011054

ABSTRACT

BACKGROUNDPatients with coronavirus disease 2019 (COVID-19) develop pneumonia generally associated with lymphopenia and a severe inflammatory response due to uncontrolled cytokine release. These mediators are transcriptionally regulated by the JAK/STAT signaling pathways, which can be disabled by small molecules.METHODSWe treated a group of patients (n = 20) with baricitinib according to an off-label use of the drug. The study was designed as an observational, longitudinal trial and approved by the local ethics committee. The patients were treated with 4 mg baricitinib twice daily for 2 days, followed by 4 mg per day for the remaining 7 days. Changes in the immune phenotype and expression of phosphorylated STAT3 (p-STAT3) in blood cells were evaluated and correlated with serum-derived cytokine levels and antibodies against severe acute respiratory syndrome-coronavirus 2 (anti-SARS-CoV-2). In a single treated patient, we also evaluated the alteration of myeloid cell functional activity.RESULTSWe provide evidence that patients treated with baricitinib had a marked reduction in serum levels of IL-6, IL-1ß, and TNF-α, a rapid recovery of circulating T and B cell frequencies, and increased antibody production against the SARS-CoV-2 spike protein, all of which were clinically associated with a reduction in the need for oxygen therapy and a progressive increase in the P/F (PaO2, oxygen partial pressure/FiO2, fraction of inspired oxygen) ratio.CONCLUSIONThese data suggest that baricitinib prevented the progression to a severe, extreme form of the viral disease by modulating the patients' immune landscape and that these changes were associated with a safer, more favorable clinical outcome for patients with COVID-19 pneumonia.TRIAL REGISTRATIONClinicalTrials.gov NCT04438629.FUNDINGThis work was supported by the Fondazione Cariverona (ENACT Project) and the Fondazione TIM.


Subject(s)
Azetidines/administration & dosage , COVID-19 , Off-Label Use , Purines/administration & dosage , Pyrazoles/administration & dosage , SARS-CoV-2 , Sulfonamides/administration & dosage , Aged , Aged, 80 and over , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , B-Lymphocytes/pathology , COVID-19/blood , COVID-19/drug therapy , COVID-19/immunology , COVID-19/pathology , Cytokines/blood , Cytokines/immunology , Female , Humans , Longitudinal Studies , Male , Middle Aged , SARS-CoV-2/immunology , SARS-CoV-2/metabolism , Severity of Illness Index , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , T-Lymphocytes/pathology
19.
Br J Pharmacol ; 177(21): 4990-4994, 2020 11.
Article in English | MEDLINE | ID: covidwho-1007351

ABSTRACT

Severe pneumonia which shares several of the features of acute respiratory distress syndrome (ARDS) is the main cause of morbidity and mortality in Coronavirus disease 19 (Covid-19) for which there is no effective treatment, so far. ARDS is caused and sustained by an uncontrolled inflammatory activation characterized by a massive release of cytokines (cytokine storm), diffuse lung oedema, inflammatory cell infiltration, and disseminated coagulation. Macrophage and T lymphocyte dysfunction plays a central role in this syndrome. In several experimental in vitro and in vivo models, many of these pathophysiological changes are triggered by stimulation of the P2X7 receptor. We hypothesize that this receptor might be an ideal candidate to target in Covid-19-associated severe pneumonia. LINKED ARTICLES: This article is part of a themed issue on The Pharmacology of COVID-19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc.


Subject(s)
Coronavirus Infections/drug therapy , Pneumonia, Viral/drug therapy , Receptors, Purinergic P2X7/drug effects , Respiratory Distress Syndrome/drug therapy , Animals , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/physiopathology , Coronavirus Infections/virology , Cytokine Release Syndrome/virology , Humans , Macrophages/pathology , Pandemics , Pneumonia, Viral/physiopathology , Pneumonia, Viral/virology , Receptors, Purinergic P2X7/metabolism , Respiratory Distress Syndrome/virology , SARS-CoV-2 , T-Lymphocytes/pathology
20.
PLoS Pathog ; 17(1): e1009153, 2021 01.
Article in English | MEDLINE | ID: covidwho-1006381

ABSTRACT

Neuropilin-1 (NRP-1), a member of a family of signaling proteins, was shown to serve as an entry factor and potentiate SARS Coronavirus 2 (SARS-CoV-2) infectivity in vitro. This cell surface receptor with its disseminated expression is important in angiogenesis, tumor progression, viral entry, axonal guidance, and immune function. NRP-1 is implicated in several aspects of a SARS-CoV-2 infection including possible spread through the olfactory bulb and into the central nervous system and increased NRP-1 RNA expression in lungs of severe Coronavirus Disease 2019 (COVID-19). Up-regulation of NRP-1 protein in diabetic kidney cells hint at its importance in a population at risk of severe COVID-19. Involvement of NRP-1 in immune function is compelling, given the role of an exaggerated immune response in disease severity and deaths due to COVID-19. NRP-1 has been suggested to be an immune checkpoint of T cell memory. It is unknown whether involvement and up-regulation of NRP-1 in COVID-19 may translate into disease outcome and long-term consequences, including possible immune dysfunction. It is prudent to further research NRP-1 and its possibility of serving as a therapeutic target in SARS-CoV-2 infections. We anticipate that widespread expression, abundance in the respiratory and olfactory epithelium, and the functionalities of NRP-1 factor into the multiple systemic effects of COVID-19 and challenges we face in management of disease and potential long-term sequelae.


Subject(s)
COVID-19/immunology , Neuropilin-1/immunology , SARS-CoV-2/immunology , Virus Internalization , COVID-19/pathology , Diabetic Nephropathies/immunology , Diabetic Nephropathies/pathology , Diabetic Nephropathies/virology , Humans , Immunologic Memory , Olfactory Bulb/immunology , Olfactory Bulb/pathology , Olfactory Bulb/virology , Respiratory Mucosa/immunology , Respiratory Mucosa/pathology , Respiratory Mucosa/virology , T-Lymphocytes/immunology , T-Lymphocytes/pathology
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