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1.
Front Cell Infect Microbiol ; 12: 893044, 2022.
Article in English | MEDLINE | ID: covidwho-1952262

ABSTRACT

Severe COVID-19 in children is rare, but the reasons underlying are unclear. Profound alterations in T cell responses have been well characterized in the course of adult severe COVID-19, but little is known about the T cell function in children with COVID-19. Here, we made three major observations in a cohort of symptomatic children with acute COVID-19: 1) a reduced frequency of circulating FoxP3+ regulatory T cells, 2) the prevalence of a TH17 polarizing microenvironment characterized by high plasma levels of IL-6, IL-23, and IL17A, and an increased frequency of CD4+ T cells expressing ROR-γt, the master regulator of TH17 development, and 3) high plasma levels of ATP together with an increased expression of the P2X7 receptor. Moreover, that plasma levels of ATP displayed an inverse correlation with the frequency of regulatory T cells but a positive correlation with the frequency of CD4+ T cells positive for the expression of ROR-γt. Collectively, our data indicate an imbalance in CD4+ T cell profiles during pediatric COVID-19 that might favor the course of inflammatory processes. This finding also suggests a possible role for the extracellular ATP in the acquisition of an inflammatory signature by the T cell compartment offering a novel understanding of the involved mechanisms.


Subject(s)
COVID-19 , Nuclear Receptor Subfamily 1, Group F, Member 3 , Adenosine Triphosphate/metabolism , Adult , CD4-Positive T-Lymphocytes/metabolism , Child , Humans , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , T-Lymphocytes, Regulatory , Th17 Cells
2.
Sci Transl Med ; 14(649): eabo0686, 2022 Jun 15.
Article in English | MEDLINE | ID: covidwho-1891729

ABSTRACT

T cell-derived pro-inflammatory cytokines are a major driver of rheumatoid arthritis (RA) pathogenesis. Although these cytokines have traditionally been attributed to CD4 T cells, we have found that CD8 T cells are notably abundant in synovium and make more interferon (IFN)-γ and nearly as much tumor necrosis factor (TNF) as their CD4 T cell counterparts. Furthermore, using unbiased high-dimensional single-cell RNA-seq and flow cytometric data, we found that the vast majority of synovial tissue and synovial fluid CD8 T cells belong to an effector CD8 T cell population characterized by high expression of granzyme K (GzmK) and low expression of granzyme B (GzmB) and perforin. Functional experiments demonstrate that these GzmK+ GzmB+ CD8 T cells are major cytokine producers with low cytotoxic potential. Using T cell receptor repertoire data, we found that CD8 GzmK+ GzmB+ T cells are clonally expanded in synovial tissues and maintain their granzyme expression and overall cell state in blood, suggesting that they are enriched in tissue but also circulate. Using GzmK and GzmB signatures, we found that GzmK-expressing CD8 T cells were also the major CD8 T cell population in the gut, kidney, and coronavirus disease 2019 (COVID-19) bronchoalveolar lavage fluid, suggesting that they form a core population of tissue-associated T cells across diseases and human tissues. We term this population tissue-enriched expressing GzmK or TteK CD8 cells. Armed to produce cytokines in response to both antigen-dependent and antigen-independent stimuli, CD8 TteK cells have the potential to drive inflammation.


Subject(s)
COVID-19 , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Cytokines/metabolism , Granzymes/metabolism , Humans
3.
Eur Rev Med Pharmacol Sci ; 26(2): 695-709, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1675568

ABSTRACT

In 2009, obesity was identified for the first time as a risk factor for increased disease severity and mortality in patients infected with the H1N1 influenza A virus. During the current COVID-19 pandemic, overweight and obesity have been described as independent risk factors of disease severity and mortality due to COVID-19. Excess visceral fat is associated with systemic chronic microinflammation, changes in adipokine release, and oxidative stress. These disturbances result in an impaired immune response, including dysfunction in lymphocyte action and antibody production. Moreover, obesity is a cause of endothelial dysfunction, pro-coagulation state, and enhanced expression of angiotensin-converting enzyme 2 (ACE-2), which contributes to the infection itself and the severity of the disease. We analyzed both the impact of obesity on the severity of COVID-19 and the potential mechanism that influences this severity. Moreover, we discuss the effect of obesity complications on the severity of disease and mortality of patients with COVID-19. Furthermore, we summarize the effectiveness of COVID-19 vaccination in patients with obesity. Finally, we analyzed the effect of the COVID-19 pandemic on mood disturbances and emotional eating and, as a consequence, the development of obesity or an increase in its severity. In summary, the studies conducted during the COVID-19 pandemic indicate that effective obesity treatment should be initiated at once. In addition, the data confirm the need to organize efficient obesity treatment systems for the sake of not only the individual but also society.


Subject(s)
COVID-19/pathology , Influenza, Human/pathology , Obesity/complications , Adipokines/metabolism , Angiotensin-Converting Enzyme 2/metabolism , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , COVID-19/complications , COVID-19/epidemiology , COVID-19/mortality , Humans , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/complications , Influenza, Human/epidemiology , Meta-Analysis as Topic , Obesity/epidemiology , Oxidative Stress , Pandemics , Risk Factors , Severity of Illness Index , Survival Analysis , TOR Serine-Threonine Kinases/metabolism
4.
Cell Rep ; 38(6): 110345, 2022 02 08.
Article in English | MEDLINE | ID: covidwho-1654153

ABSTRACT

Understanding the long-term maintenance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity is critical for predicting protection against reinfection. In an age- and gender-matched cohort of 24 participants, the association of disease severity and early immune responses on the maintenance of humoral immunity 12 months post-infection is examined. All severely affected participants maintain a stable subset of SARS-CoV-2 receptor-binding domain (RBD)-specific memory B cells (MBCs) and good neutralizing antibody breadth against the majority of the variants of concern, including the Delta variant. Modeling these immune responses against vaccine efficacy data indicate a 45%-76% protection against symptomatic infection (variant dependent). Overall, these findings indicate durable humoral responses in most participants after infection, reasonable protection against reinfection, and implicate baseline antigen-specific CD4+ T cell responses as a predictor of maintenance of antibody neutralization breadth and RBD-specific MBC levels at 12 months post-infection.


Subject(s)
Broadly Neutralizing Antibodies/metabolism , SARS-CoV-2/immunology , Adult , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Australia , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , COVID-19/immunology , Cohort Studies , Female , Humans , Immunity/immunology , Immunity, Humoral/immunology , Male , SARS-CoV-2/pathogenicity , Severity of Illness Index , Spike Glycoprotein, Coronavirus/immunology
5.
Cell ; 185(5): 847-859.e11, 2022 03 03.
Article in English | MEDLINE | ID: covidwho-1650711

ABSTRACT

We address whether T cell responses induced by different vaccine platforms (mRNA-1273, BNT162b2, Ad26.COV2.S, and NVX-CoV2373) cross-recognize early SARS-CoV-2 variants. T cell responses to early variants were preserved across vaccine platforms. By contrast, significant overall decreases were observed for memory B cells and neutralizing antibodies. In subjects ∼6 months post-vaccination, 90% (CD4+) and 87% (CD8+) of memory T cell responses were preserved against variants on average by AIM assay, and 84% (CD4+) and 85% (CD8+) preserved against Omicron. Omicron RBD memory B cell recognition was substantially reduced to 42% compared with other variants. T cell epitope repertoire analysis revealed a median of 11 and 10 spike epitopes recognized by CD4+ and CD8+ T cells, with average preservation > 80% for Omicron. Functional preservation of the majority of T cell responses may play an important role as a second-level defense against diverse variants.


Subject(s)
COVID-19 Vaccines/immunology , Memory B Cells/immunology , Memory T Cells/immunology , SARS-CoV-2/immunology , Ad26COVS1/administration & dosage , Ad26COVS1/immunology , BNT162 Vaccine/administration & dosage , BNT162 Vaccine/immunology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , COVID-19/pathology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Epitopes/immunology , Epitopes, T-Lymphocyte/immunology , Humans , Memory B Cells/metabolism , Memory T Cells/metabolism , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Vaccination
6.
Nat Commun ; 13(1): 440, 2022 01 21.
Article in English | MEDLINE | ID: covidwho-1641960

ABSTRACT

Dysregulated immune responses against the SARS-CoV-2 virus are instrumental in severe COVID-19. However, the immune signatures associated with immunopathology are poorly understood. Here we use multi-omics single-cell analysis to probe the dynamic immune responses in hospitalized patients with stable or progressive course of COVID-19, explore V(D)J repertoires, and assess the cellular effects of tocilizumab. Coordinated profiling of gene expression and cell lineage protein markers shows that S100Ahi/HLA-DRlo classical monocytes and activated LAG-3hi T cells are hallmarks of progressive disease and highlights the abnormal MHC-II/LAG-3 interaction on myeloid and T cells, respectively. We also find skewed T cell receptor repertories in expanded effector CD8+ clones, unmutated IGHG+ B cell clones, and mutated B cell clones with stable somatic hypermutation frequency over time. In conclusion, our in-depth immune profiling reveals dyssynchrony of the innate and adaptive immune interaction in progressive COVID-19.


Subject(s)
Adaptive Immunity/immunology , COVID-19/immunology , Gene Expression Profiling/methods , Immunity, Innate/immunology , SARS-CoV-2/immunology , Single-Cell Analysis/methods , Adaptive Immunity/drug effects , Adaptive Immunity/genetics , Aged , Antibodies, Monoclonal, Humanized/therapeutic use , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , COVID-19/drug therapy , COVID-19/genetics , Cells, Cultured , Female , Gene Expression Regulation/drug effects , Gene Expression Regulation/immunology , Humans , Immunity, Innate/drug effects , Immunity, Innate/genetics , Male , RNA-Seq/methods , Receptors, Antigen, B-Cell/genetics , Receptors, Antigen, B-Cell/immunology , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/immunology , SARS-CoV-2/drug effects , SARS-CoV-2/physiology
7.
Cell Death Differ ; 29(8): 1486-1499, 2022 08.
Article in English | MEDLINE | ID: covidwho-1641945

ABSTRACT

Severe SARS-CoV-2 infections are characterized by lymphopenia, but the mechanisms involved are still elusive. Based on our knowledge of HIV pathophysiology, we hypothesized that SARS-CoV-2 infection-mediated lymphopenia could also be related to T cell apoptosis. By comparing intensive care unit (ICU) and non-ICU COVID-19 patients with age-matched healthy donors, we found a strong positive correlation between plasma levels of soluble FasL (sFasL) and T cell surface expression of Fas/CD95 with the propensity of T cells to die and CD4 T cell counts. Plasma levels of sFasL and T cell death are correlated with CXCL10 which is part of the signature of 4 biomarkers of disease severity (ROC, 0.98). We also found that members of the Bcl-2 family had modulated in the T cells of COVID-19 patients. More importantly, we demonstrated that the pan-caspase inhibitor, Q-VD, prevents T cell death by apoptosis and enhances Th1 transcripts. Altogether, our results are compatible with a model in which T-cell apoptosis accounts for T lymphopenia in individuals with severe COVID-19. Therefore, a strategy aimed at blocking caspase activation could be beneficial for preventing immunodeficiency in COVID-19 patients.


Subject(s)
COVID-19 , Lymphopenia , Apoptosis , CD4-Positive T-Lymphocytes/metabolism , Caspases/metabolism , Fas Ligand Protein , Humans , SARS-CoV-2 , T-Lymphocytes/metabolism , fas Receptor/metabolism
8.
Nat Commun ; 13(1): 19, 2022 01 10.
Article in English | MEDLINE | ID: covidwho-1616981

ABSTRACT

T cells play a vital role in combatting SARS-CoV-2 and forming long-term memory responses. Whereas extensive structural information is available on neutralizing antibodies against SARS-CoV-2, such information on SARS-CoV-2-specific T-cell receptors (TCRs) bound to their peptide-MHC targets is lacking. Here we determine the structures of a public and a private TCR from COVID-19 convalescent patients in complex with HLA-A2 and two SARS-CoV-2 spike protein epitopes (YLQ and RLQ). The structures reveal the basis for selection of particular TRAV and TRBV germline genes by the public but not the private TCR, and for the ability of the TCRs to recognize natural variants of RLQ but not YLQ. Neither TCR recognizes homologous epitopes from human seasonal coronaviruses. By elucidating the mechanism for TCR recognition of an immunodominant yet variable epitope (YLQ) and a conserved but less commonly targeted epitope (RLQ), this study can inform prospective efforts to design vaccines to elicit pan-coronavirus immunity.


Subject(s)
COVID-19/immunology , Epitopes, T-Lymphocyte/immunology , HLA-A2 Antigen/immunology , Receptors, Antigen, T-Cell/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/virology , COVID-19/virology , Epitopes, T-Lymphocyte/metabolism , HLA-A2 Antigen/chemistry , HLA-A2 Antigen/metabolism , Humans , Immunodominant Epitopes/immunology , Immunodominant Epitopes/metabolism , Jurkat Cells , K562 Cells , Peptides/chemistry , Peptides/immunology , Peptides/metabolism , Protein Binding , Protein Conformation , Receptors, Antigen, T-Cell/chemistry , Receptors, Antigen, T-Cell/metabolism , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Surface Plasmon Resonance/methods
9.
Front Immunol ; 12: 797919, 2021.
Article in English | MEDLINE | ID: covidwho-1608316

ABSTRACT

Persistence of protective immunity for SARS-CoV-2 is important against reinfection. Knowledge on SARS-CoV-2 immunity in pediatric patients is currently lacking. We opted to assess the SARS-CoV-2 adaptive immunity in recovered children and adolescents, addressing the pediatrics specific immunity towards COVID-19. Two independent assays were performed to investigate humoral and cellular immunological memory in pediatric convalescent COVID-19 patients. Specifically, RBD IgG, CD4+, and CD8+ T cell responses were identified and quantified in recovered children and adolescents. SARS-CoV-2-specific RBD IgG detected in recovered patients had a half-life of 121.6 days and estimated duration of 7.9 months compared with baseline levels in controls. The specific T cell response was shown to be independent of days after diagnosis. Both CD4+ and CD8+ T cells showed robust responses not only to spike (S) peptides (a main target of vaccine platforms) but were also similarly activated when stimulated by membrane (M) and nuclear (N) peptides. Importantly, we found the differences in the adaptive responses were correlated with the age of the recovered patients. The CD4+ T cell response to SARS-CoV-2 S peptide in children aged <12 years correlated with higher SARS-CoV-2 RBD IgG levels, suggesting the importance of a T cell-dependent humoral response in younger children under 12 years. Both cellular and humoral immunity against SARS-CoV-2 infections can be induced in pediatric patients. Our important findings provide fundamental knowledge on the immune memory responses to SARS-CoV-2 in recovered pediatric patients.


Subject(s)
Adaptive Immunity/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Convalescence , SARS-CoV-2/immunology , Adolescent , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/virology , COVID-19/virology , Child , Child, Preschool , Female , Humans , Immunity, Humoral/immunology , Immunoglobulin G/immunology , Male , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism
10.
Front Immunol ; 12: 760249, 2021.
Article in English | MEDLINE | ID: covidwho-1581341

ABSTRACT

Background: The humoral and cellular immune responses to SARS-COV-2 vaccination remain to be elucidated in hemodialysis (HD) patients and kidney transplant recipients (KTRs), considering their baseline immunosuppressed status. The aim of our study was to assess the associations of vaccine-induced antibody responses with circulating lymphocytes sub-populations and their respective patterns of alterations in maintenance HD patients and KTRs. Materials and Methods: We included 34 HD patients and 54 KTRs who received two doses of the mRNA-vaccine BNT162b2. Lymphocyte subpopulations were analyzed by flow cytometry before vaccination (T0), before the second vaccine dose (T1) and 2 weeks after the second dose (T2). The anti-SARS-CoV2 antibody response was assessed at T1 and at T2. Results: 31 HD patients (91.8%) and 16 KTRs (29.6%) became seropositive at T2. HD patients who became seropositive following the first dose displayed higher CD19+ B lymphocytes compared to their seronegative HD counterparts. A positive correlation was established between CD19+ B cells counts and antibody titers at all time-points in both groups (p < 0.001). KTRs showed higher naïve CD4+CD45RA+ T helper cells compared to HD patients at baseline and T2 whereas HD patients displayed higher memory CD45RO+ T cells compared to KTRs at T2. The naïve CD4+CD45RA to memory CD4+CD45RO+ T helper cells fraction was negatively associated with antibody production in both groups. Conclusions: Our study provides a potential conceptual framework for monitoring vaccination efficacy in HD patients and KTRs considering the correlation established between CD19+ B cells, generation of memory CD4+ T helper cells and anti SARS-CoV2 antibody response to vaccination.


Subject(s)
Antibody Formation/immunology , B-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/immunology , Immunity, Humoral , Immunocompromised Host , Immunologic Memory , B-Lymphocytes/metabolism , Biomarkers , CD4-Positive T-Lymphocytes/metabolism , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/immunology , Female , Humans , Immunophenotyping , Kidney Transplantation , Lymphocyte Count , Male , Renal Dialysis , SARS-CoV-2/immunology
11.
Cells ; 11(1)2021 12 27.
Article in English | MEDLINE | ID: covidwho-1580992

ABSTRACT

Coronavirus disease 2019 (COVID-19) is a global infectious disease caused by the SARS-CoV-2 coronavirus. T cells play an essential role in the body's fighting against the virus invasion, and the T cell receptor (TCR) is crucial in T cell-mediated virus recognition and clearance. However, little has been known about the features of T cell response in convalescent COVID-19 patients. In this study, using 5'RACE technology and PacBio sequencing, we analyzed the TCR repertoire of COVID-19 patients after recovery for 2 weeks and 6 months compared with the healthy donors. The TCR clustering and CDR3 annotation were exploited to discover groups of patient-specific TCR clonotypes with potential SARS-CoV-2 antigen specificities. We first identified CD4+ and CD8+ T cell clones with certain clonal expansion after infection, and then observed the preferential recombination usage of V(D) J gene segments in CD4+ and CD8+ T cells of COVID-19 patients with different convalescent stages. More important, the TRBV6-5-TRBD2-TRBJ2-7 combination with high frequency was shared between CD4+ T and CD8+ T cells of different COVID-19 patients. Finally, we found the dominant characteristic motifs of the CDR3 sequence between recovered COVID-19 and healthy control. Our study provides novel insights on TCR in COVID-19 with different convalescent phases, contributing to our understanding of the immune response induced by SARS-CoV-2.


Subject(s)
COVID-19/immunology , High-Throughput Nucleotide Sequencing/methods , Immunity/immunology , Receptors, Antigen, T-Cell/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Aged , Amino Acid Sequence , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/virology , COVID-19/metabolism , COVID-19/virology , Cells, Cultured , Complementarity Determining Regions/genetics , Complementarity Determining Regions/immunology , Convalescence , Female , Humans , Male , Middle Aged , Patient Acuity , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/metabolism , Receptors, Antigen, T-Cell, alpha-beta/genetics , Receptors, Antigen, T-Cell, alpha-beta/immunology , Receptors, Antigen, T-Cell, alpha-beta/metabolism , SARS-CoV-2/physiology , T-Lymphocytes/metabolism , T-Lymphocytes/virology
13.
Eur J Immunol ; 52(2): 352-355, 2022 02.
Article in English | MEDLINE | ID: covidwho-1530141

ABSTRACT

A late presenter AIDS patient with severe T cell depletion presented non-severe COVID-19 symptoms, with prolonged viral shedding. Our case report supports the hypothesis that an effective T cell response may be dispensable for the control of COVID-19 progression to severe forms, while it may be necessary for SARS-CoV-2 clearance.


Subject(s)
Acquired Immunodeficiency Syndrome/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Acquired Immunodeficiency Syndrome/blood , Adult , CD4 Lymphocyte Count , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , COVID-19/blood , Female , Humans , SARS-CoV-2/metabolism
14.
FEBS Lett ; 595(17): 2257-2270, 2021 09.
Article in English | MEDLINE | ID: covidwho-1439663

ABSTRACT

HIV preferentially infects α4 ß7 + CD4 T cells, forming latent reservoirs that contribute to HIV persistence during antiretroviral therapy. However, the properties of α4 ß7 + CD4 T cells in blood and mucosal compartments remain understudied. Employing two distinct models of HIV infection, HIV-infected humans and simian-human immunodeficiency virus (SHIV)-infected rhesus macaques, we show that α4 ß7 + CD4 T cells in blood are enriched for genes regulating cell cycle progression and cellular metabolism. Unlike their circulating counterparts, rectal α4 ß7 + CD4 T cells exhibited a core tissue-residency gene expression program. These features were conserved across primate species, indicating that the environment influences memory T-cell transcriptional networks. Our findings provide an important molecular foundation for understanding the role of α4 ß7 in HIV infection.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , HIV Infections/blood , Integrins/metabolism , Adult , Animals , COVID-19/blood , COVID-19/virology , Cell Cycle , Cell Proliferation , Gastric Mucosa/cytology , Gastric Mucosa/virology , Gene Expression Regulation , Humans , Immunization , Macaca mulatta , Male , Simian Acquired Immunodeficiency Syndrome/blood , Simian Acquired Immunodeficiency Syndrome/virology
15.
mBio ; 12(5): e0159921, 2021 10 26.
Article in English | MEDLINE | ID: covidwho-1398577

ABSTRACT

Cellular immunity may be involved in organ damage and rehabilitation in patients with coronavirus disease 2019 (COVID-19). We aimed to delineate immunological features of COVID-19 patients with pulmonary sequelae (PS) 1 year after discharge. Fifty COVID-19 survivors were recruited and classified according to radiological characteristics, including 24 patients with PS and 26 patients without PS. Phenotypic and functional characteristics of immune cells were evaluated by multiparametric flow cytometry. Patients with PS had an increased proportion of natural killer (NK) cells and a lower percentage of B cells than patients without PS. Phenotypic and functional features of T cells in patients with PS were predominated by the accumulation of CD4-positive (CD4+) T cells secreting interleukin 17A (IL-17A), short-lived effector-like CD8+ T cells (CD27-negative [CD27-] CD62L-), and senescent T cells with excessive secretion of granzyme B/perforin/interferon gamma (IFN-γ). NK cells were characterized by the excessive secretion of granzyme B and perforin and the downregulation of NKP30 and NKP46; highly activated NKT and γδ T cells exhibited NKP30 and TIM-3 upregulation and NKB1 downregulation in patients with PS. However, immunosuppressive cells were comparable between the two groups. The interrelationship of immune cells in COVID-19 was intrinsically identified, whereby T cells secreting IL-2, IL-4, and IL-17A were enriched among CD28+ and CD57- cells and cells secreting perforin/granzyme B/IFN-γ/tumor necrosis factor alpha (TNF-α)-expressed markers of terminal differentiation. CD57+ NK cells, CD4+Perforin+ T cells, and CD8+ CD27+ CD62L+ T cells were identified as the independent predictors for residual lesions. Overall, our findings unveil the profound imbalance of immune landscape that may correlate with organ damage and rehabilitation in COVID-19. IMPORTANCE A considerable proportion of COVID-19 survivors have residual lung lesions such as ground-glass opacity and fiber streak shadow. To determine the relationship between host immunity and residual lung lesions, we performed an extensive analysis of immune responses in convalescent patients with COVID-19 1 year after discharge. We found significant differences in immunological characteristics between patients with pulmonary sequelae and patients without pulmonary sequelae 1 year after discharge. Our study highlights the profound imbalance of immune landscape in the COVID-19 patients with pulmonary sequelae, characterized by the robust activation of cytotoxic T cells, NK cells, and γδ T cells, as well as the deficiencies of immunosuppressive cells. Importantly, CD57+ NK cells, CD4+Perforin+ T cells, and CD8+ CD27+ CD62L+ T cells were identified as the independent predictors for residual lesions.


Subject(s)
COVID-19/immunology , Adult , CD28 Antigens/metabolism , CD4-Positive T-Lymphocytes/metabolism , CD57 Antigens/metabolism , CD8-Positive T-Lymphocytes/metabolism , COVID-19/metabolism , Female , Hepatitis A Virus Cellular Receptor 2/metabolism , Humans , Immunity, Cellular/immunology , Immunity, Cellular/physiology , Interleukin-17/metabolism , Interleukin-2/metabolism , Interleukin-4/metabolism , L-Selectin/metabolism , Male , Middle Aged , Natural Cytotoxicity Triggering Receptor 1/metabolism , Natural Cytotoxicity Triggering Receptor 3/metabolism
16.
Nat Immunol ; 22(5): 620-626, 2021 05.
Article in English | MEDLINE | ID: covidwho-1387432

ABSTRACT

The immune response to SARS-CoV-2 is critical in controlling disease, but there is concern that waning immunity may predispose to reinfection. We analyzed the magnitude and phenotype of the SARS-CoV-2-specific T cell response in 100 donors at 6 months following infection. T cell responses were present by ELISPOT and/or intracellular cytokine staining analysis in all donors and characterized by predominant CD4+ T cell responses with strong interleukin (IL)-2 cytokine expression. Median T cell responses were 50% higher in donors who had experienced a symptomatic infection, indicating that the severity of primary infection establishes a 'set point' for cellular immunity. T cell responses to spike and nucleoprotein/membrane proteins were correlated with peak antibody levels. Furthermore, higher levels of nucleoprotein-specific T cells were associated with preservation of nucleoprotein-specific antibody level although no such correlation was observed in relation to spike-specific responses. In conclusion, our data are reassuring that functional SARS-CoV-2-specific T cell responses are retained at 6 months following infection.


Subject(s)
Antigens, Viral/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Immunity, Cellular , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Viral/blood , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/virology , COVID-19/blood , COVID-19/virology , Female , Host-Pathogen Interactions , Humans , Interleukin-2/blood , Male , Middle Aged , Phenotype , SARS-CoV-2/pathogenicity , Time Factors , Young Adult
17.
Cell Mol Immunol ; 18(8): 1847-1860, 2021 08.
Article in English | MEDLINE | ID: covidwho-1387308

ABSTRACT

CD4+ T cells orchestrate adaptive immune responses via binding of antigens to their receptors through specific peptide/MHC-II complexes. To study these responses, it is essential to identify protein-derived MHC-II peptide ligands that constitute epitopes for T cell recognition. However, generating cells expressing single MHC-II alleles and isolating these proteins for use in peptide elution or binding studies is time consuming. Here, we express human MHC alleles (HLA-DR4 and HLA-DQ6) as native, noncovalent αß dimers on yeast cells for direct flow cytometry-based screening of peptide ligands from selected antigens. We demonstrate rapid, accurate identification of DQ6 ligands from pre-pro-hypocretin, a narcolepsy-related immunogenic target. We also identify 20 DR4-binding SARS-CoV-2 spike peptides homologous to SARS-CoV-1 epitopes, and one spike peptide overlapping with the reported SARS-CoV-2 epitope recognized by CD4+ T cells from unexposed individuals carrying DR4 subtypes. Our method is optimized for immediate application upon the emergence of novel pathogens.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , COVID-19/metabolism , Epitopes, T-Lymphocyte/metabolism , HLA-DQ Antigens/metabolism , HLA-DR4 Antigen/metabolism , Saccharomyces cerevisiae/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Two-Hybrid System Techniques , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , COVID-19/genetics , COVID-19/immunology , Epitopes, T-Lymphocyte/genetics , Epitopes, T-Lymphocyte/immunology , Flow Cytometry , HLA-DQ Antigens/genetics , HLA-DQ Antigens/immunology , HLA-DR4 Antigen/genetics , HLA-DR4 Antigen/immunology , Ligands , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
18.
Mol Immunol ; 138: 121-127, 2021 10.
Article in English | MEDLINE | ID: covidwho-1347762

ABSTRACT

AIMS: Coronavirus disease 2019 (COVID-19) is a novel viral infection threatening worldwide health as currently there exists no effective treatment strategy and vaccination programs are not publicly available yet. T lymphocytes play an important role in antiviral defenses. However, T cell frequency and functionality may be affected during the disease. MATERIAL AND METHODS: Total blood samples were collected from patients with mild and severe COVID-19, and the total lymphocyte number, as well as CD4+ and CD8 + T cells were assessed using flowcytometry. Besides, the expression of exhausted T cell markers was evaluated. The levels of proinflammatory cytokines were also investigated in the serum of all patients using enzyme-linked immunesorbent assay (ELISA). Finally, the obtained results were analyzed along with laboratory serological reports. RESULTS: COVID-19 patients showed lymphopenia and reduced CD4+ and CD8 + T cells, as well as high percentage of PD-1 expression by T cells, especially in severe cases. Serum secretion of TNF-α, IL-1ß, and IL-2 receptor (IL-2R) were remarkably increased in patients with severe symptoms, as compared with healthy controls. Moreover, high levels of triglyceride (TG) and low density lipoprotein cholesterol (LDL-C), were correlated with the severity of the disease. CONCLUSION: Reduced number and function of T cells were observed in COVID-19 patients, especially in severe patients. Meanwhile, the secretion of proinflammatory cytokines was increased as the disease developed. High level of serum IL-2R was also considered as a sign of lymphopenia. Additionally, hypercholesterolemia and hyperlipidemia could be important prognostic factors in determining the severity of the infection.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Lymphopenia/immunology , SARS-CoV-2/immunology , Adult , Aged , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/virology , COVID-19/metabolism , COVID-19/virology , Cholesterol, LDL/blood , Cytokines/blood , Cytokines/immunology , Cytokines/metabolism , Disease Progression , Female , Humans , Lymphocyte Count , Lymphopenia/blood , Lymphopenia/virology , Male , Middle Aged , Prognosis , SARS-CoV-2/physiology , Severity of Illness Index , Triglycerides/blood
19.
Arch Pathol Lab Med ; 145(11): 1341-1349, 2021 11 01.
Article in English | MEDLINE | ID: covidwho-1337799

ABSTRACT

CONTEXT.­: Case reports and rare case series have demonstrated variable placental pathology in the setting of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In rare small studies demonstrating infection of the placental parenchyma, histologic manifestations have included variable degrees of histiocytic intervillositis, perivillous fibrin deposition, and syncytiotrophoblast necrosis. OBJECTIVE.­: To characterize the placental pathologic features of SARS-CoV-2-infected placentas, irrespective of fetal-maternal transmission, and to examine the frequency of C4d activation in such cases. DESIGN.­: A retrospective study of 7 placentas from mothers with active SARS-CoV-2 infection and placental infection as demonstrated by RNA in situ hybridization was conducted. RESULTS.­: There were 6 placentas from live-born neonates (5 singletons, 1 nonfused diamniotic-dichorionic twin placenta), and 1 was from a stillbirth. A total of 5 of the 8 neonates (including the stillbirth) tested negative for SARS-CoV-2, and all were negative for neonatal infection. The remaining 3 neonates were well at time of discharge. All placentas were positive for SARS-CoV-2 infection by RNA in situ hybridization and demonstrated variable degrees of histiocytic intervillositis, perivillous fibrin deposition, and trophoblast necrosis. Three cases demonstrated features of fetal vascular malperfusion. CD68 highlighted intervillous histiocytes. C4d expression was present along the villous borders in 6 of 7 cases. CONCLUSIONS.­: SARS-CoV-2 placentitis is defined by the triad of histiocytic intervillositis, perivillous fibrin deposition, and trophoblast necrosis. The features may occur in cases without confirmed transplacental transmission. The damage caused by SARS-CoV-2 placentitis is likely mediated by complement activation.


Subject(s)
COVID-19/diagnosis , Placenta Diseases/diagnosis , Placenta/pathology , Placenta/virology , Pregnancy Complications, Infectious/diagnosis , Adult , Biomarkers/metabolism , CD4-Positive T-Lymphocytes/metabolism , COVID-19/immunology , COVID-19/pathology , COVID-19/transmission , COVID-19 Testing , Female , Humans , Infant, Newborn , Infectious Disease Transmission, Vertical , Lymphocyte Activation , Male , Placenta Diseases/immunology , Placenta Diseases/pathology , Placenta Diseases/virology , Pregnancy , Pregnancy Complications, Infectious/immunology , Pregnancy Complications, Infectious/pathology , Pregnancy Complications, Infectious/virology , Retrospective Studies , Stillbirth
20.
Nat Commun ; 12(1): 4515, 2021 07 26.
Article in English | MEDLINE | ID: covidwho-1327196

ABSTRACT

The in vivo phenotypic profile of T cells reactive to severe acute respiratory syndrome (SARS)-CoV-2 antigens remains poorly understood. Conventional methods to detect antigen-reactive T cells require in vitro antigenic re-stimulation or highly individualized peptide-human leukocyte antigen (pHLA) multimers. Here, we use single-cell RNA sequencing to identify and profile SARS-CoV-2-reactive T cells from Coronavirus Disease 2019 (COVID-19) patients. To do so, we induce transcriptional shifts by antigenic stimulation in vitro and take advantage of natural T cell receptor (TCR) sequences of clonally expanded T cells as barcodes for 'reverse phenotyping'. This allows identification of SARS-CoV-2-reactive TCRs and reveals phenotypic effects introduced by antigen-specific stimulation. We characterize transcriptional signatures of currently and previously activated SARS-CoV-2-reactive T cells, and show correspondence with phenotypes of T cells from the respiratory tract of patients with severe disease in the presence or absence of virus in independent cohorts. Reverse phenotyping is a powerful tool to provide an integrated insight into cellular states of SARS-CoV-2-reactive T cells across tissues and activation states.


Subject(s)
COVID-19/immunology , Gene Expression Profiling/methods , Sequence Analysis, RNA/methods , Single-Cell Analysis/methods , T-Lymphocytes/metabolism , Aged , Aged, 80 and over , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , COVID-19/epidemiology , COVID-19/virology , Cells, Cultured , Cohort Studies , Female , Humans , Male , Middle Aged , Pandemics , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/immunology , Receptors, Antigen, T-Cell/metabolism , SARS-CoV-2/physiology , T-Lymphocytes/virology
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