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1.
Cell ; 185(4): 603-613.e15, 2022 02 17.
Article in English | MEDLINE | ID: covidwho-1588149

ABSTRACT

SARS-CoV-2 mRNA vaccines induce robust anti-spike (S) antibody and CD4+ T cell responses. It is not yet clear whether vaccine-induced follicular helper CD4+ T (TFH) cell responses contribute to this outstanding immunogenicity. Using fine-needle aspiration of draining axillary lymph nodes from individuals who received the BNT162b2 mRNA vaccine, we evaluated the T cell receptor sequences and phenotype of lymph node TFH. Mining of the responding TFH T cell receptor repertoire revealed a strikingly immunodominant HLA-DPB1∗04-restricted response to S167-180 in individuals with this allele, which is among the most common HLA alleles in humans. Paired blood and lymph node specimens show that while circulating S-specific TFH cells peak one week after the second immunization, S-specific TFH persist at nearly constant frequencies for at least six months. Collectively, our results underscore the key role that robust TFH cell responses play in establishing long-term immunity by this efficacious human vaccine.


Subject(s)
COVID-19/immunology , COVID-19/virology , Immunity/immunology , SARS-CoV-2/immunology , T Follicular Helper Cells/immunology , Vaccination , Vaccines, Synthetic/immunology , /immunology , Adult , B-Lymphocytes/immunology , COVID-19/blood , Clone Cells , Cohort Studies , Cytokines/metabolism , Female , Germinal Center/immunology , HLA-DP beta-Chains/immunology , Humans , Immunodominant Epitopes/immunology , Jurkat Cells , Lymph Nodes/metabolism , Male , Middle Aged , Peptides/chemistry , Peptides/metabolism , Protein Multimerization , Receptors, Antigen, T-Cell/metabolism
2.
Sci Immunol ; 6(56)2021 02 23.
Article in English | MEDLINE | ID: covidwho-1099742

ABSTRACT

Hyperinflammation contributes to lung injury and subsequent acute respiratory distress syndrome (ARDS) with high mortality in patients with severe coronavirus disease 2019 (COVID-19). To understand the underlying mechanisms involved in lung pathology, we investigated the role of the lung-specific immune response. We profiled immune cells in bronchoalveolar lavage fluid and blood collected from COVID-19 patients with severe disease and bacterial pneumonia patients not associated with viral infection. By tracking T cell clones across tissues, we identified clonally expanded tissue-resident memory-like Th17 cells (Trm17 cells) in the lungs even after viral clearance. These Trm17 cells were characterized by a a potentially pathogenic cytokine expression profile of IL17A and CSF2 (GM-CSF). Interactome analysis suggests that Trm17 cells can interact with lung macrophages and cytotoxic CD8+ T cells, which have been associated with disease severity and lung damage. High IL-17A and GM-CSF protein levels in the serum of COVID-19 patients were associated with a more severe clinical course. Collectively, our study suggests that pulmonary Trm17 cells are one potential orchestrator of the hyperinflammation in severe COVID-19.


Subject(s)
COVID-19/immunology , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Immunologic Memory , Lung/immunology , Th17 Cells/metabolism , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/immunology , COVID-19/complications , COVID-19/pathology , Clone Cells , Humans , Inflammation/etiology , Inflammation/immunology , Lung/pathology , Myeloid Cells , Pneumonia, Bacterial/immunology , Th17 Cells/immunology
3.
Elife ; 102021 01 05.
Article in English | MEDLINE | ID: covidwho-1006839

ABSTRACT

COVID-19 is a global pandemic caused by the SARS-CoV-2 coronavirus. T cells play a key role in the adaptive antiviral immune response by killing infected cells and facilitating the selection of virus-specific antibodies. However, neither the dynamics and cross-reactivity of the SARS-CoV-2-specific T-cell response nor the diversity of resulting immune memory is well understood. In this study, we use longitudinal high-throughput T-cell receptor (TCR) sequencing to track changes in the T-cell repertoire following two mild cases of COVID-19. In both donors, we identified CD4+ and CD8+ T-cell clones with transient clonal expansion after infection. We describe characteristic motifs in TCR sequences of COVID-19-reactive clones and show preferential occurrence of these motifs in publicly available large dataset of repertoires from COVID-19 patients. We show that in both donors, the majority of infection-reactive clonotypes acquire memory phenotypes. Certain T-cell clones were detected in the memory fraction at the pre-infection time point, suggesting participation of pre-existing cross-reactive memory T cells in the immune response to SARS-CoV-2.


Subject(s)
COVID-19/immunology , Immunologic Memory , Receptors, Antigen, T-Cell/genetics , Amino Acid Sequence , COVID-19/physiopathology , Cross Reactions , Epitope Mapping , Female , Gene Library , Histocompatibility Testing , Humans , Longitudinal Studies , Male , Receptors, Antigen, T-Cell/chemistry , SARS-CoV-2/physiology , Severity of Illness Index , T-Lymphocytes/immunology
4.
Immunity ; 53(6): 1258-1271.e5, 2020 12 15.
Article in English | MEDLINE | ID: covidwho-988080

ABSTRACT

CD4+ T cells reactive against SARS-CoV-2 can be found in unexposed individuals, and these are suggested to arise in response to common cold coronavirus (CCCoV) infection. Here, we utilized SARS-CoV-2-reactive CD4+ T cell enrichment to examine the antigen avidity and clonality of these cells, as well as the relative contribution of CCCoV cross-reactivity. SARS-CoV-2-reactive CD4+ memory T cells were present in virtually all unexposed individuals examined, displaying low functional avidity and multiple, highly variable cross-reactivities that were not restricted to CCCoVs. SARS-CoV-2-reactive CD4+ T cells from COVID-19 patients lacked cross-reactivity to CCCoVs, irrespective of strong memory T cell responses against CCCoV in all donors analyzed. In severe but not mild COVID-19, SARS-CoV-2-specific T cells displayed low functional avidity and clonality, despite increased frequencies. Our findings identify low-avidity CD4+ T cell responses as a hallmark of severe COVID-19 and argue against a protective role for CCCoV-reactive T cells in SARS-CoV-2 infection.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , COVID-19/immunology , Receptors, Antigen, T-Cell/metabolism , Rhinovirus/immunology , SARS-CoV-2/immunology , Antigens, Viral/immunology , Cells, Cultured , Cross Reactions , Disease Progression , Environmental Exposure , Humans , Immunologic Memory , Lymphocyte Activation , Protein Binding , Severity of Illness Index , T-Cell Antigen Receptor Specificity
5.
Immunity ; 53(6): 1296-1314.e9, 2020 12 15.
Article in English | MEDLINE | ID: covidwho-965599

ABSTRACT

Temporal resolution of cellular features associated with a severe COVID-19 disease trajectory is needed for understanding skewed immune responses and defining predictors of outcome. Here, we performed a longitudinal multi-omics study using a two-center cohort of 14 patients. We analyzed the bulk transcriptome, bulk DNA methylome, and single-cell transcriptome (>358,000 cells, including BCR profiles) of peripheral blood samples harvested from up to 5 time points. Validation was performed in two independent cohorts of COVID-19 patients. Severe COVID-19 was characterized by an increase of proliferating, metabolically hyperactive plasmablasts. Coinciding with critical illness, we also identified an expansion of interferon-activated circulating megakaryocytes and increased erythropoiesis with features of hypoxic signaling. Megakaryocyte- and erythroid-cell-derived co-expression modules were predictive of fatal disease outcome. The study demonstrates broad cellular effects of SARS-CoV-2 infection beyond adaptive immune cells and provides an entry point toward developing biomarkers and targeted treatments of patients with COVID-19.


Subject(s)
COVID-19/metabolism , Erythroid Cells/pathology , Megakaryocytes/physiology , Plasma Cells/physiology , SARS-CoV-2/physiology , Adult , Aged , Aged, 80 and over , Biomarkers , Blood Circulation , COVID-19/immunology , Cells, Cultured , Cohort Studies , Disease Progression , Female , Gene Expression Profiling , Humans , Male , Middle Aged , Proteomics , Sequence Analysis, RNA , Severity of Illness Index , Single-Cell Analysis
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