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1.
Science ; 375(6585): 1080, 2022 Mar 11.
Article in English | MEDLINE | ID: covidwho-1779303

ABSTRACT

Study finds human version of mouse immune regulators.


Subject(s)
Autoimmune Diseases/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Cytotoxic/immunology , Animals , Humans , Mice , Receptors, KIR/analysis
2.
Crit Rev Microbiol ; 46(6): 689-702, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-1730391

ABSTRACT

Intensive worldwide efforts are underway to determine both the pathogenesis of SARS-CoV-2 infection and the immune responses in COVID-19 patients in order to develop effective therapeutics and vaccines. One type of cell that may contribute to these immune responses is the γδ T lymphocyte, which plays a key role in immunosurveillance of the mucosal and epithelial barriers by rapidly responding to pathogens. Although found in low numbers in blood, γδ T cells consist the majority of tissue-resident T cells and participate in the front line of the host immune defense. Previous studies have demonstrated the critical protective role of γδ T cells in immune responses to other respiratory viruses, including SARS-CoV-1. However, no studies have profoundly investigated these cells in COVID-19 patients to date. γδ T cells can be safely expanded in vivo using existing inexpensive FDA-approved drugs such as bisphosphonate, in order to test its protective immune response to SARS-CoV-2. To support this line of research, we review insights gained from previous coronavirus research, along with recent findings, discussing the potential role of γδ T cells in controlling SARS-CoV-2. We conclude by proposing several strategies to enhance γδ T cell's antiviral function, which may be used in developing therapies for COVID-19.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , T-Lymphocyte Subsets/immunology , Animals , Betacoronavirus/genetics , COVID-19 , Coronavirus Infections/virology , Humans , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Virus Replication
3.
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
4.
Front Immunol ; 12: 785946, 2021.
Article in English | MEDLINE | ID: covidwho-1674333

ABSTRACT

Although cellular and molecular mediators of the immune system have the potential to be prognostic indicators of disease outcomes, temporal interference between diseases might affect the immune mediators, and make them difficult to predict disease complications. Today one of the most important challenges is predicting the prognosis of COVID-19 in the context of other inflammatory diseases such as traumatic injuries. Many diseases with inflammatory properties are usually polyphasic and the kinetics of inflammatory mediators in various inflammatory diseases might be different. To find the most appropriate evaluation time of immune mediators to accurately predict COVID-19 prognosis in the trauma environment, researchers must investigate and compare cellular and molecular alterations based on their kinetics after the start of COVID-19 symptoms and traumatic injuries. The current review aimed to investigate the similarities and differences of common inflammatory mediators (C-reactive protein, procalcitonin, ferritin, and serum amyloid A), cytokine/chemokine levels (IFNs, IL-1, IL-6, TNF-α, IL-10, and IL-4), and immune cell subtypes (neutrophil, monocyte, Th1, Th2, Th17, Treg and CTL) based on the kinetics between patients with COVID-19 and trauma. The mediators may help us to accurately predict the severity of COVID-19 complications and follow up subsequent clinical interventions. These findings could potentially help in a better understanding of COVID-19 and trauma pathogenesis.


Subject(s)
COVID-19/diagnosis , SARS-CoV-2/physiology , T-Lymphocyte Subsets/immunology , Th1 Cells/immunology , Wounds and Injuries/diagnosis , COVID-19/complications , COVID-19/immunology , Cytokines/metabolism , Humans , Inflammation Mediators/metabolism , Prognosis , Wounds and Injuries/complications , Wounds and Injuries/immunology
5.
Viruses ; 14(1)2022 01 12.
Article in English | MEDLINE | ID: covidwho-1631201

ABSTRACT

γδ T cells are innate cells able to quickly eliminate pathogens or infected/tumoral cells by their antiviral and adjuvancy activities. The role of γδ T cells during Dengue Viral Infection (DENV) infection is not fully elucidated. Nevertheless, human primary γδ T cells have been shown to kill in vitro DENV-infected cells, thus highlighting their possible antiviral function. The aim of this work was to characterize the phenotype and function of Vδ2 T cells in DENV patients. Fifteen DENV patients were enrolled for this study and peripheral blood mononuclear cells (PBMC) were used to analyze Vδ2-T-cell frequency, differentiation profile, activation/exhaustion status, and functionality by multiparametric flow cytometry. Our data demonstrated that DENV infection was able to significantly reduce Vδ2-T-cell frequency and to increase their activation (CD38 and HLA-DR) and exhaustion markers (PD-1 and TIM-3). Furthermore, Vδ2 T cells showed a reduced capability to produce IFN-γ after phosphoantigenic stimulation that can be associated to TIM-3 expression. Several studies are needed to depict the possible clinical impact of γδ-T-cell impairment on disease severity and to define the antiviral and immunoregulatory activities of γδ T cells in the first phases of infection.


Subject(s)
Dengue/immunology , Hepatitis A Virus Cellular Receptor 2/metabolism , Interferon-gamma/metabolism , Intraepithelial Lymphocytes/immunology , Adaptation, Physiological , Adult , Flow Cytometry , Hepatitis A Virus Cellular Receptor 2/genetics , Humans , Immunity, Innate , Leukocytes, Mononuclear/immunology , Lymphocyte Activation/immunology , Male , Middle Aged , T-Lymphocyte Subsets/immunology
6.
J Med Virol ; 94(5): 2089-2101, 2022 05.
Article in English | MEDLINE | ID: covidwho-1626431

ABSTRACT

COVID-19 is a disease characterized by acute respiratory failure and is a major health problem worldwide. Here, we aimed to investigate the role of CD39 expression in Treg cell subsets in COVID-19 immunopathogenesis and its relationship to disease severity. One hundred and ninety COVID-19 patients (juveniles, adults) and 43 volunteers as healthy controls were enrolled in our study. Flow cytometric analysis was performed using a 10-color monoclonal antibody panel from peripheral blood samples. In adult patients, CD39+ Tregs increased with disease severity. In contrast, CD39+ Tregs were decreased in juvenile patients in an age-dependent manner. Overall, our study reveals an interesting profile of CD39-expressing Tregs in adult and juvenile cases of COVID-19. Our results provide a better understanding of the possible role of Tregs in the mechanism of immune response in COVID-19 cases.


Subject(s)
Apyrase , COVID-19 , T-Lymphocytes, Regulatory , Adult , Apyrase/biosynthesis , Apyrase/immunology , Apyrase/metabolism , COVID-19/immunology , COVID-19/metabolism , Forkhead Transcription Factors , Humans , Severity of Illness Index , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Regulatory/immunology
7.
Front Immunol ; 12: 789735, 2021.
Article in English | MEDLINE | ID: covidwho-1581322

ABSTRACT

Background: The host immune response has a prominent role in the progression and outcome of SARS-CoV-2 infection. Lymphopenia has been described as an important feature of SARS-CoV-2 infection and has been associated with severe disease manifestation. Lymphocyte dysregulation and hyper-inflammation have been shown to be associated with a more severe clinical course; however, a T cell subpopulation whose dysfunction correlate with disease progression has yet to be identify. Methods: We performed an immuno-phenotypic analysis of T cell sub-populations in peripheral blood from patients affected by different severity of COVID-19 (n=60) and undergoing a different clinical evolution. Clinical severity was established based on a modified WHO score considering both ventilation support and respiratory capacity (PaO2/FiO2 ratio). The ability of circulating cells at baseline to predict the probability of clinical aggravation was explored through multivariate regression analyses. Results: The immuno-phenotypic analysis performed by multi-colour flow cytometry confirmed that patients suffering from severe COVID-19 harboured significantly reduced circulating T cell subsets, especially for CD4+ T, Th1, and regulatory T cells. Peripheral T cells also correlated with parameters associated with disease severity, i.e., PaO2/FiO2 ratio and inflammation markers. CD4+ T cell subsets showed an important significant association with clinical evolution, with patients presenting markedly decreased regulatory T cells at baseline having a significantly higher risk of aggravation. Importantly, the combination of gender and regulatory T cells allowed distinguishing between improved and worsened patients with an area under the ROC curve (AUC) of 82%. Conclusions: The present study demonstrates the association between CD4+ T cell dysregulation and COVID-19 severity and progression. Our results support the importance of analysing baseline regulatory T cell levels, since they were revealed able to predict the clinical worsening during hospitalization. Regulatory T cells assessment soon after hospital admission could thus allow a better clinical stratification and patient management.


Subject(s)
COVID-19/epidemiology , COVID-19/immunology , Hospitalization , Lymphocyte Count , SARS-CoV-2/immunology , T-Lymphocytes, Regulatory/immunology , Biomarkers , COVID-19/diagnosis , COVID-19/virology , COVID-19 Serological Testing , Cytokines/blood , Cytokines/metabolism , Disease Progression , Humans , Immunophenotyping , Inflammation Mediators/blood , Inflammation Mediators/metabolism , Prognosis , Public Health Surveillance , ROC Curve , Severity of Illness Index , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocytes, Regulatory/metabolism
8.
J Infect Dis ; 224(12): 2010-2019, 2021 12 15.
Article in English | MEDLINE | ID: covidwho-1574912

ABSTRACT

BACKGROUND: Characterizing the longevity and quality of cellular immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enhances understanding of coronavirus disease 2019 (COVID-19) immunity that influences clinical outcomes. Prior studies suggest SARS-CoV-2-specific T cells are present in peripheral blood 10 months after infection. Analysis of the function, durability, and diversity of cellular response long after natural infection, over a range of ages and disease phenotypes, is needed to identify preventative and therapeutic interventions. METHODS: We identified participants in our multisite longitudinal, prospective cohort study 12 months after SARS-CoV-2 infection representing a range of disease severity. We investigated function, phenotypes, and frequency of T cells specific for SARS-CoV-2 using intracellular cytokine staining and spectral flow cytometry, and compared magnitude of SARS-CoV-2-specific antibodies. RESULTS: SARS-CoV-2-specific antibodies and T cells were detected 12 months postinfection. Severe acute illness was associated with higher frequencies of SARS-CoV-2-specific CD4 T cells and antibodies at 12 months. In contrast, polyfunctional and cytotoxic T cells responsive to SARS-CoV-2 were identified in participants over a wide spectrum of disease severity. CONCLUSIONS: SARS-CoV-2 infection induces polyfunctional memory T cells detectable at 12 months postinfection, with higher frequency noted in those who experienced severe disease.


Subject(s)
COVID-19/immunology , COVID-19/virology , Immunologic Memory , SARS-CoV-2/immunology , T-Lymphocyte Subsets/immunology , Adult , Antibodies, Viral , Antigens, Viral , Biomarkers , COVID-19/diagnosis , COVID-19/epidemiology , Female , Humans , Immunity, Cellular , Longitudinal Studies , Male , Middle Aged , Prospective Studies , Severity of Illness Index , T-Lymphocyte Subsets/metabolism , Time Factors
9.
Front Cell Infect Microbiol ; 11: 624483, 2021.
Article in English | MEDLINE | ID: covidwho-1574395

ABSTRACT

The immune response type organized against viral infection is determinant in the prognosis of some infections. This work has aimed to study Th polarization in acute COVID-19 and its possible association with the outcome through an observational prospective study. Fifty-eight COVID-19 patients were recruited in the Medicine Department of the hospital "12 de Octubre," 55 patients remaining after losses to follow-up. Four groups were established according to maximum degree of disease progression. T-helper cell percentages and phenotypes, analyzed by flow cytometer, and serum cytokines levels, analyzed by Luminex, were evaluated when the microbiological diagnosis (acute phase) of the disease was obtained. Our study found a significant reduction of %Th1 and %Th17 cells with higher activated %Th2 cells in the COVID-19 patients compared with reference population. A higher percent of senescent Th2 cells was found in the patients who died than in those who survived. Senescent Th2 cell percentage was an independent risk factor for death (OR: 13.88) accompanied by the numbers of total lymphocytes (OR: 0.15) with an AUC of 0.879. COVID-19 patients showed a profile of pro-inflammatory serum cytokines compared to controls, with higher levels of IL-2, IL-6, IL-15, and IP-10. IL-10 and IL-13 were also elevated in patients compared to controls. Patients who did not survive presented significantly higher levels of IL-15 than those who recovered. No significant differences were observed according to disease progression groups. The study has shown that increased levels of IL-15 and a high Th2 response are associated with a fatal outcome of the disease.


Subject(s)
COVID-19/immunology , SARS-CoV-2/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Helper-Inducer/immunology , Adult , Aged , COVID-19/blood , COVID-19/pathology , Cytokines/blood , Disease Progression , Female , Humans , Immunity , Male , Middle Aged , Multivariate Analysis , Prospective Studies , Th1 Cells/immunology , Th17 Cells/immunology , Th2 Cells/immunology
10.
Viruses ; 13(11)2021 11 03.
Article in English | MEDLINE | ID: covidwho-1542790

ABSTRACT

The detailed characterization of human γδ T lymphocyte differentiation at the single-cell transcriptomic (scRNAseq) level in tumors and patients with coronavirus disease 2019 (COVID-19) requires both a reference differentiation trajectory of γδ T cells and a robust mapping method for additional γδ T lymphocytes. Here, we incepted such a method to characterize thousands of γδ T lymphocytes from (n = 95) patients with cancer or adult and pediatric COVID-19 disease. We found that cancer patients with human papillomavirus-positive head and neck squamous cell carcinoma and Epstein-Barr virus-positive Hodgkin's lymphoma have γδ tumor-infiltrating T lymphocytes that are more prone to recirculate from the tumor and avoid exhaustion. In COVID-19, both TCRVγ9 and TCRVγnon9 subsets of γδ T lymphocytes relocalize from peripheral blood mononuclear cells (PBMC) to the infected lung tissue, where their advanced differentiation, tissue residency, and exhaustion reflect T cell activation. Although severe COVID-19 disease increases both recruitment and exhaustion of γδ T lymphocytes in infected lung lesions but not blood, the anti-IL6R therapy with Tocilizumab promotes γδ T lymphocyte differentiation in patients with COVID-19. PBMC from pediatric patients with acute COVID-19 disease display similar γδ T cell lymphopenia to that seen in adult patients. However, blood γδ T cells from children with the COVID-19-related multisystem inflammatory syndrome are not lymphodepleted, but they are differentiated as in healthy PBMC. These findings suggest that some virus-induced memory γδ T lymphocytes durably persist in the blood of adults and could subsequently infiltrate and recirculate in tumors.


Subject(s)
COVID-19/immunology , Lymphocytes, Tumor-Infiltrating/immunology , Neoplasms/immunology , RNA-Seq , Receptors, Antigen, T-Cell, gamma-delta/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Adult , Bronchoalveolar Lavage Fluid/immunology , COVID-19/complications , Cell Differentiation , Child , Head and Neck Neoplasms/immunology , Head and Neck Neoplasms/virology , Herpesvirus 4, Human/isolation & purification , Hodgkin Disease/immunology , Hodgkin Disease/virology , Humans , Lung/immunology , Lymphocyte Activation , Lymphocyte Count , Lymphocytes, Tumor-Infiltrating/metabolism , Lymphocytes, Tumor-Infiltrating/physiology , Neoplasms/virology , Papillomaviridae/isolation & purification , Severity of Illness Index , Single-Cell Analysis , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocyte Subsets/physiology
11.
PLoS One ; 16(11): e0258743, 2021.
Article in English | MEDLINE | ID: covidwho-1511818

ABSTRACT

BCG vaccination is known to induce innate immune memory, which confers protection against heterologous infections. However, the effect of BCG vaccination on the conventional adaptive immune cells subsets is not well characterized. We investigated the impact of BCG vaccination on the frequencies of T cell subsets and common gamma c (γc) cytokines in a group of healthy elderly individuals (age 60-80 years) at one month post vaccination as part of our clinical study to examine the effect of BCG on COVID-19. Our results demonstrate that BCG vaccination induced enhanced frequencies of central (p<0.0001) and effector memory (p<0.0001) CD4+ T cells and diminished frequencies of naïve (p<0.0001), transitional memory (p<0.0001), stem cell memory (p = 0.0001) CD4+ T cells and regulatory T cells. In addition, BCG vaccination induced enhanced frequencies of central (p = 0.0008), effector (p<0.0001) and terminal effector memory (p<0.0001) CD8+ T cells and diminished frequencies of naïve (p<0.0001), transitional memory (p<0.0001) and stem cell memory (p = 0.0034) CD8+T cells. BCG vaccination also induced enhanced plasma levels of IL-7 (p<0.0001) and IL-15 (p = 0.0020) but diminished levels of IL-2 (p = 0.0033) and IL-21 (p = 0.0020). Thus, BCG vaccination was associated with enhanced memory T cell subsets as well as memory enhancing γc cytokines in elderly individuals, suggesting its ability to induce non-specific adaptive immune responses.


Subject(s)
BCG Vaccine/immunology , Cytokines/immunology , Immunologic Memory/immunology , Interleukin Receptor Common gamma Subunit/immunology , Aged , Aged, 80 and over , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Female , Humans , Interleukins/immunology , Male , Middle Aged , Mycobacterium tuberculosis/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Regulatory/immunology , Vaccination/methods
12.
Viruses ; 13(11)2021 11 03.
Article in English | MEDLINE | ID: covidwho-1502529

ABSTRACT

The detailed characterization of human γδ T lymphocyte differentiation at the single-cell transcriptomic (scRNAseq) level in tumors and patients with coronavirus disease 2019 (COVID-19) requires both a reference differentiation trajectory of γδ T cells and a robust mapping method for additional γδ T lymphocytes. Here, we incepted such a method to characterize thousands of γδ T lymphocytes from (n = 95) patients with cancer or adult and pediatric COVID-19 disease. We found that cancer patients with human papillomavirus-positive head and neck squamous cell carcinoma and Epstein-Barr virus-positive Hodgkin's lymphoma have γδ tumor-infiltrating T lymphocytes that are more prone to recirculate from the tumor and avoid exhaustion. In COVID-19, both TCRVγ9 and TCRVγnon9 subsets of γδ T lymphocytes relocalize from peripheral blood mononuclear cells (PBMC) to the infected lung tissue, where their advanced differentiation, tissue residency, and exhaustion reflect T cell activation. Although severe COVID-19 disease increases both recruitment and exhaustion of γδ T lymphocytes in infected lung lesions but not blood, the anti-IL6R therapy with Tocilizumab promotes γδ T lymphocyte differentiation in patients with COVID-19. PBMC from pediatric patients with acute COVID-19 disease display similar γδ T cell lymphopenia to that seen in adult patients. However, blood γδ T cells from children with the COVID-19-related multisystem inflammatory syndrome are not lymphodepleted, but they are differentiated as in healthy PBMC. These findings suggest that some virus-induced memory γδ T lymphocytes durably persist in the blood of adults and could subsequently infiltrate and recirculate in tumors.


Subject(s)
COVID-19/immunology , Lymphocytes, Tumor-Infiltrating/immunology , Neoplasms/immunology , RNA-Seq , Receptors, Antigen, T-Cell, gamma-delta/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Adult , Bronchoalveolar Lavage Fluid/immunology , COVID-19/complications , Cell Differentiation , Child , Head and Neck Neoplasms/immunology , Head and Neck Neoplasms/virology , Herpesvirus 4, Human/isolation & purification , Hodgkin Disease/immunology , Hodgkin Disease/virology , Humans , Lung/immunology , Lymphocyte Activation , Lymphocyte Count , Lymphocytes, Tumor-Infiltrating/metabolism , Lymphocytes, Tumor-Infiltrating/physiology , Neoplasms/virology , Papillomaviridae/isolation & purification , Severity of Illness Index , Single-Cell Analysis , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocyte Subsets/physiology
13.
J Infect Dis ; 224(12): 2010-2019, 2021 12 15.
Article in English | MEDLINE | ID: covidwho-1483460

ABSTRACT

BACKGROUND: Characterizing the longevity and quality of cellular immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enhances understanding of coronavirus disease 2019 (COVID-19) immunity that influences clinical outcomes. Prior studies suggest SARS-CoV-2-specific T cells are present in peripheral blood 10 months after infection. Analysis of the function, durability, and diversity of cellular response long after natural infection, over a range of ages and disease phenotypes, is needed to identify preventative and therapeutic interventions. METHODS: We identified participants in our multisite longitudinal, prospective cohort study 12 months after SARS-CoV-2 infection representing a range of disease severity. We investigated function, phenotypes, and frequency of T cells specific for SARS-CoV-2 using intracellular cytokine staining and spectral flow cytometry, and compared magnitude of SARS-CoV-2-specific antibodies. RESULTS: SARS-CoV-2-specific antibodies and T cells were detected 12 months postinfection. Severe acute illness was associated with higher frequencies of SARS-CoV-2-specific CD4 T cells and antibodies at 12 months. In contrast, polyfunctional and cytotoxic T cells responsive to SARS-CoV-2 were identified in participants over a wide spectrum of disease severity. CONCLUSIONS: SARS-CoV-2 infection induces polyfunctional memory T cells detectable at 12 months postinfection, with higher frequency noted in those who experienced severe disease.


Subject(s)
COVID-19/immunology , COVID-19/virology , Immunologic Memory , SARS-CoV-2/immunology , T-Lymphocyte Subsets/immunology , Adult , Antibodies, Viral , Antigens, Viral , Biomarkers , COVID-19/diagnosis , COVID-19/epidemiology , Female , Humans , Immunity, Cellular , Longitudinal Studies , Male , Middle Aged , Prospective Studies , Severity of Illness Index , T-Lymphocyte Subsets/metabolism , Time Factors
14.
J Investig Med ; 70(1): 61-67, 2022 01.
Article in English | MEDLINE | ID: covidwho-1455731

ABSTRACT

Long COVID is characterized by the emergence of multiple debilitating symptoms following SARS-CoV-2 infection. Its etiology is unclear and it often follows a mild acute illness. Anecdotal reports of gradual clinical responses to histamine receptor antagonists (HRAs) suggest a histamine-dependent mechanism that is distinct from anaphylaxis, possibly mediated by T cells, which are also regulated by histamine. T cell perturbations have been previously reported in post-viral syndromes, but the T cell landscape in patients who have recovered from mild COVID-19 and its relationship to both long COVID symptoms and any symptomatic response to HRA remain underexplored. We addressed these questions in an observational study of 65 individuals who had recovered from mild COVID-19. Participants were surveyed between 87 and 408 days after the onset of acute symptoms; none had required hospitalization, 16 had recovered uneventfully, and 49 had developed long COVID. Symptoms were quantified using a structured questionnaire and T cell subsets enumerated in a standard diagnostic assay. Patients with long-COVID had reduced CD4+ and CD8+ effector memory (EM) cell numbers and increased PD-1 (programmed cell death protein 1) expression on central memory (CM) cells, whereas the asymptomatic participants had reduced CD8+ EM cells only and increased CD28 expression on CM cells. 72% of patients with long COVID who received HRA reported clinical improvement, although T cell profiling did not clearly distinguish those who responded to HRA. This study demonstrates that T cell perturbations persist for several months after mild COVID-19 and are associated with long COVID symptoms.


Subject(s)
COVID-19/complications , COVID-19/immunology , Histamine Antagonists/therapeutic use , T-Lymphocytes , Adult , Aged , COVID-19/diagnosis , Female , Histamine , Humans , Male , Middle Aged , SARS-CoV-2/immunology , T-Lymphocyte Subsets/immunology , Young Adult
15.
Front Immunol ; 12: 743924, 2021.
Article in English | MEDLINE | ID: covidwho-1441113

ABSTRACT

Antigen-specific vaccines developed for the COVID-19 pandemic demonstrate a remarkable achievement and are currently being used in high income countries with much success. However, new SARS-CoV-2 variants are threatening this success via mutations that lessen the efficacy of antigen-specific antibodies. One simple approach to assisting with this issue is focusing on strategies that build on the non-specific protection afforded by the innate immune response. The BCG vaccine has been shown to provide broad protection beyond tuberculosis disease, including against respiratory viruses, and ongoing studies are investigating its efficacy as a tool against SARS-CoV-2. Gamma delta (γδ) T cells, particularly the Vδ2 subtype, undergo rapid expansion after BCG vaccination due to MHC-independent mechanisms. Consequently, γδ T cells can produce diverse defenses against virally infected cells, including direct cytotoxicity, death receptor ligands, and pro-inflammatory cytokines. They can also assist in stimulating the adaptive immune system. BCG is affordable, commonplace and non-specific, and therefore could be a useful tool to initiate innate protection against new SARS-CoV-2 variants. However, considerations must also be made to BCG vaccine supply and the prioritization of countries where it is most needed to combat tuberculosis first and foremost.


Subject(s)
BCG Vaccine/therapeutic use , COVID-19/prevention & control , SARS-CoV-2 , T-Lymphocyte Subsets/drug effects , Animals , BCG Vaccine/economics , BCG Vaccine/pharmacology , Costs and Cost Analysis , Humans , T-Lymphocyte Subsets/immunology , Vaccination/economics
17.
J Exp Med ; 218(4)2021 04 05.
Article in English | MEDLINE | ID: covidwho-1387677

ABSTRACT

SARS-CoV-2 is responsible for an ongoing pandemic that has affected millions of individuals around the globe. To gain further understanding of the immune response in recovered individuals, we measured T cell responses in paired samples obtained an average of 1.3 and 6.1 mo after infection from 41 individuals. The data indicate that recovered individuals show persistent polyfunctional SARS-CoV-2 antigen-specific memory that could contribute to rapid recall responses. Recovered individuals also show enduring alterations in relative overall numbers of CD4+ and CD8+ memory T cells, including expression of activation/exhaustion markers, and cell division.


Subject(s)
COVID-19/immunology , COVID-19/virology , Host-Pathogen Interactions/immunology , Immunity, Cellular , SARS-CoV-2/immunology , Adult , Aged , Antigens, Viral/immunology , Biomarkers , Female , Humans , Immunophenotyping , Lymphocyte Count , Male , Middle Aged , T-Cell Antigen Receptor Specificity , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Young Adult
18.
Front Immunol ; 12: 720090, 2021.
Article in English | MEDLINE | ID: covidwho-1374235

ABSTRACT

Male sex and old age are risk factors for COVID-19 severity, but the underlying causes are unknown. A possible explanation for this might be the differences in immunological profiles in males and the elderly before the infection. With this in mind, we analyzed the abundance of circulating proteins and immune populations associated with severe COVID-19 in 2 healthy cohorts. Besides, given the seasonal profile of COVID-19, the seasonal response against SARS-CoV-2 could also be different in the elderly and males. Therefore, PBMCs of female, male, young, and old subjects in different seasons of the year were stimulated with heat-inactivated SARS-CoV-2 to investigate the season-dependent anti-SARS-CoV-2 immune response. We found that several T cell subsets, which are known to be depleted in severe COVID-19 patients, were intrinsically less abundant in men and older individuals. Plasma proteins increasing with disease severity, including HGF, IL-8, and MCP-1, were more abundant in the elderly and males. Upon in vitro SARS-CoV-2 stimulation, the elderly produced significantly more IL-1RA and had a dysregulated IFNγ response with lower production in the fall compared with young individuals. Our results suggest that the immune characteristics of severe COVID-19, described by a differential abundance of immune cells and circulating inflammatory proteins, are intrinsically present in healthy men and the elderly. This might explain the susceptibility of men and the elderly to SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , Adolescent , Adult , Age Factors , Aged , Aging/immunology , Blood Proteins/immunology , COVID-19/physiopathology , Cohort Studies , Disease Susceptibility , Female , Humans , Immunity, Cellular , Immunologic Factors , Male , Middle Aged , Patient Acuity , Risk Assessment , Seasons , Sex Factors , T-Lymphocyte Subsets/immunology , Young Adult
19.
Sci Immunol ; 6(62)2021 08 10.
Article in English | MEDLINE | ID: covidwho-1352519

ABSTRACT

To understand how a protective immune response against SARS-CoV-2 develops over time, we integrated phenotypic, transcriptional and repertoire analyses on PBMCs from mild and severe COVID-19 patients during and after infection, and compared them to healthy donors (HD). A type I IFN-response signature marked all the immune populations from severe patients during the infection. Humoral immunity was dominated by IgG production primarily against the RBD and N proteins, with neutralizing antibody titers increasing post infection and with disease severity. Memory B cells, including an atypical FCRL5+ T-BET+ memory subset, increased during the infection, especially in patients with mild disease. A significant reduction of effector memory, CD8+ T cells frequency characterized patients with severe disease. Despite such impairment, we observed robust clonal expansion of CD8+ T lymphocytes, while CD4+ T cells were less expanded and skewed toward TCM and TH2-like phenotypes. MAIT cells were also expanded, but only in patients with mild disease. Terminally differentiated CD8+ GZMB+ effector cells were clonally expanded both during the infection and post-infection, while CD8+ GZMK+ lymphocytes were more expanded post-infection and represented bona fide memory precursor effector cells. TCR repertoire analysis revealed that only highly proliferating T cell clonotypes, which included SARS-CoV-2-specific cells, were maintained post-infection and shared between the CD8+ GZMB+ and GZMK+ subsets. Overall, this study describes the development of immunity against SARS-CoV-2 and identifies an effector CD8+ T cell population with memory precursor-like features.


Subject(s)
COVID-19/genetics , COVID-19/immunology , Host-Pathogen Interactions/immunology , Immunophenotyping , SARS-CoV-2/immunology , Transcriptome , Adult , Aged , Antibodies, Viral/immunology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Biomarkers , COVID-19/virology , Cell Plasticity/genetics , Cell Plasticity/immunology , Clonal Evolution/immunology , Female , Gene Expression Profiling , Humans , Immunoglobulin Isotypes/immunology , Immunologic Memory , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Lymphocyte Count , Male , Middle Aged , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism
20.
Immunol Lett ; 234: 16-32, 2021 06.
Article in English | MEDLINE | ID: covidwho-1173426

ABSTRACT

Inflammasomes are cytosolic multiprotein complexes that crucially contribute to host defense against pathogens but are also involved in the pathogenesis of autoinflammatory diseases. Inflammasome formation leads to activation of effector caspases (caspase-1, 4, 5, or 11), the proteolytic maturation of IL-1ß and IL-18 as well as cleavage of the pore-forming protein Gasdermin D. Dendritic cells are major regulators of immune responses as they bridge innate and adaptive immunity. We here summarize the current knowledge on inflammasome expression and formation in murine bone marrow-, human monocyte-derived as well as murine and human primary dendritic cells. Further, we discuss both, the beneficial and detrimental, involvement of inflammasome activation in dendritic cells in cancer, infections, and autoimmune diseases. As inflammasome activation is typically accompanied by Gasdermin d-mediated pyroptosis, which is an inflammatory form of programmed cell death, inflammasome formation in dendritic cells seems ill-advised. Therefore, we propose that hyperactivation, which is inflammasome activation without the induction of pyroptosis, may be a general model of inflammasome activation in dendritic cells to enhance Th1, Th17 as well as cytotoxic T cell responses.


Subject(s)
Dendritic Cells/immunology , Dendritic Cells/metabolism , Inflammasomes/metabolism , Animals , Biomarkers , Cell Communication/genetics , Cell Communication/immunology , Cytokines/metabolism , Disease Susceptibility/immunology , Humans , Immunomodulation , Inflammation/etiology , Inflammation/metabolism , Inflammation/pathology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism
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