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1.
Nat Rev Immunol ; 22(8): 465-470, 2022 08.
Article in English | MEDLINE | ID: covidwho-1984394

ABSTRACT

During the COVID-19 pandemic, much of the media focus has been on adaptive immunity, particularly antibody levels and memory T cells. However, immunologists have been striving to decipher how SARS-CoV-2 infection impacts our first line of defence, namely the innate immune system. In early 2022, Program staff from the NIAID at the NIH organized a workshop focusing on the innate immune response to SARS-CoV-2 infection and during COVID-19, which was chaired by Ralph Baric, Jenny Ting and John Lambris. Following the meeting, Nature Reviews Immunology invited some of the organizers and speakers to share their thoughts on the key discussion points.


Subject(s)
COVID-19 , Adaptive Immunity , Humans , Immunity, Innate , Pandemics , SARS-CoV-2
2.
Proc Natl Acad Sci U S A ; 119(28): e2204607119, 2022 07 12.
Article in English | MEDLINE | ID: covidwho-1908385

ABSTRACT

Messenger RNA (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are highly effective at inducing protective immunity. However, weak antibody responses are seen in some individuals, and cellular correlates of immunity remain poorly defined, especially for B cells. Here we used unbiased approaches to longitudinally dissect primary antibody, plasmablast, and memory B cell (MBC) responses to the two-dose mRNA-1273 vaccine in SARS-CoV-2-naive adults. Coordinated immunoglobulin A (IgA) and IgG antibody responses were preceded by bursts of spike-specific plasmablasts after both doses but earlier and more intensely after dose 2. While antibody and B cell cellular responses were generally robust, they also varied within the cohort and decreased over time after a dose-2 peak. Both antigen-nonspecific postvaccination plasmablast frequency after dose 1 and their spike-specific counterparts early after dose 2 correlated with subsequent antibody levels. This correlation between early plasmablasts and antibodies remained for titers measured at 6 months after vaccination. Several distinct antigen-specific MBC populations emerged postvaccination with varying kinetics, including two MBC populations that correlated with 2- and 6-month antibody titers. Both were IgG-expressing MBCs: one less mature, appearing as a correlate after the first dose, while the other MBC correlate showed a more mature and resting phenotype, emerging as a correlate later after dose 2. This latter MBC was also a major contributor to the sustained spike-specific MBC response observed at month 6. Thus, these plasmablasts and MBCs that emerged after both the first and second doses with distinct kinetics are potential determinants of the magnitude and durability of antibodies in response to mRNA-based vaccination.


Subject(s)
2019-nCoV Vaccine mRNA-1273 , Antibody Formation , B-Lymphocytes , COVID-19 , RNA, Messenger , SARS-CoV-2 , 2019-nCoV Vaccine mRNA-1273/administration & dosage , 2019-nCoV Vaccine mRNA-1273/immunology , B-Lymphocytes/immunology , COVID-19/prevention & control , Humans , Immunity, Cellular , Immunoglobulin A/blood , Immunoglobulin A/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , RNA, Messenger/administration & dosage , RNA, Messenger/immunology , SARS-CoV-2/immunology , Vaccination
3.
Immunity ; 54(5): 1083-1095.e7, 2021 05 11.
Article in English | MEDLINE | ID: covidwho-1179682

ABSTRACT

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening post-infectious complication occurring unpredictably weeks after mild or asymptomatic SARS-CoV-2 infection. We profiled MIS-C, adult COVID-19, and healthy pediatric and adult individuals using single-cell RNA sequencing, flow cytometry, antigen receptor repertoire analysis, and unbiased serum proteomics, which collectively identified a signature in MIS-C patients that correlated with disease severity. Despite having no evidence of active infection, MIS-C patients had elevated S100A-family alarmins and decreased antigen presentation signatures, indicative of myeloid dysfunction. MIS-C patients showed elevated expression of cytotoxicity genes in NK and CD8+ T cells and expansion of specific IgG-expressing plasmablasts. Clinically severe MIS-C patients displayed skewed memory T cell TCR repertoires and autoimmunity characterized by endothelium-reactive IgG. The alarmin, cytotoxicity, TCR repertoire, and plasmablast signatures we defined have potential for application in the clinic to better diagnose and potentially predict disease severity early in the course of MIS-C.


Subject(s)
COVID-19/immunology , COVID-19/pathology , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/pathology , Adolescent , Alarmins/immunology , Autoantibodies/immunology , CD8-Positive T-Lymphocytes/immunology , Child , Child, Preschool , Cytotoxicity, Immunologic/genetics , Endothelium/immunology , Endothelium/pathology , Humans , Killer Cells, Natural/immunology , Myeloid Cells/immunology , Plasma Cells/immunology , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/immunology , Severity of Illness Index
4.
Cell ; 184(7): 1836-1857.e22, 2021 04 01.
Article in English | MEDLINE | ID: covidwho-1077815

ABSTRACT

COVID-19 exhibits extensive patient-to-patient heterogeneity. To link immune response variation to disease severity and outcome over time, we longitudinally assessed circulating proteins as well as 188 surface protein markers, transcriptome, and T cell receptor sequence simultaneously in single peripheral immune cells from COVID-19 patients. Conditional-independence network analysis revealed primary correlates of disease severity, including gene expression signatures of apoptosis in plasmacytoid dendritic cells and attenuated inflammation but increased fatty acid metabolism in CD56dimCD16hi NK cells linked positively to circulating interleukin (IL)-15. CD8+ T cell activation was apparent without signs of exhaustion. Although cellular inflammation was depressed in severe patients early after hospitalization, it became elevated by days 17-23 post symptom onset, suggestive of a late wave of inflammatory responses. Furthermore, circulating protein trajectories at this time were divergent between and predictive of recovery versus fatal outcomes. Our findings stress the importance of timing in the analysis, clinical monitoring, and therapeutic intervention of COVID-19.


Subject(s)
COVID-19/immunology , Cytokines/metabolism , Dendritic Cells/metabolism , Gene Expression/immunology , Killer Cells, Natural/metabolism , Severity of Illness Index , Adult , Aged , Aged, 80 and over , Biomarkers/metabolism , COVID-19/mortality , Case-Control Studies , Dendritic Cells/cytology , Female , Humans , Killer Cells, Natural/cytology , Longitudinal Studies , Male , Middle Aged , Transcriptome/immunology , Young Adult
5.
JCI Insight ; 6(1)2021 01 11.
Article in English | MEDLINE | ID: covidwho-1027164

ABSTRACT

Immune and inflammatory responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contribute to disease severity of coronavirus disease 2019 (COVID-19). However, the utility of specific immune-based biomarkers to predict clinical outcome remains elusive. Here, we analyzed levels of 66 soluble biomarkers in 175 Italian patients with COVID-19 ranging from mild/moderate to critical severity and assessed type I IFN-, type II IFN-, and NF-κB-dependent whole-blood transcriptional signatures. A broad inflammatory signature was observed, implicating activation of various immune and nonhematopoietic cell subsets. Discordance between IFN-α2a protein and IFNA2 transcript levels in blood suggests that type I IFNs during COVID-19 may be primarily produced by tissue-resident cells. Multivariable analysis of patients' first samples revealed 12 biomarkers (CCL2, IL-15, soluble ST2 [sST2], NGAL, sTNFRSF1A, ferritin, IL-6, S100A9, MMP-9, IL-2, sVEGFR1, IL-10) that when increased were independently associated with mortality. Multivariate analyses of longitudinal biomarker trajectories identified 8 of the aforementioned biomarkers (IL-15, IL-2, NGAL, CCL2, MMP-9, sTNFRSF1A, sST2, IL-10) and 2 additional biomarkers (lactoferrin, CXCL9) that were substantially associated with mortality when increased, while IL-1α was associated with mortality when decreased. Among these, sST2, sTNFRSF1A, IL-10, and IL-15 were consistently higher throughout the hospitalization in patients who died versus those who recovered, suggesting that these biomarkers may provide an early warning of eventual disease outcome.


Subject(s)
COVID-19/immunology , COVID-19/mortality , Adrenal Cortex Hormones/therapeutic use , Adult , Aged , Anti-Bacterial Agents/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Antiviral Agents/therapeutic use , Azithromycin/therapeutic use , Biomarkers , COVID-19/genetics , COVID-19/therapy , Calgranulin B/genetics , Calgranulin B/immunology , Case-Control Studies , Chemokine CCL2/genetics , Chemokine CCL2/immunology , Chemokine CXCL9/genetics , Chemokine CXCL9/immunology , Enzyme Inhibitors/therapeutic use , Female , Ferritins/genetics , Ferritins/immunology , Gene Expression Profiling , Humans , Hydroxychloroquine/therapeutic use , Immunologic Factors/therapeutic use , Interferon Type I/genetics , Interferon Type I/immunology , Interferon-gamma/genetics , Interferon-gamma/immunology , Interleukin-1 Receptor-Like 1 Protein/genetics , Interleukin-1 Receptor-Like 1 Protein/immunology , Interleukin-10/genetics , Interleukin-10/immunology , Interleukin-15/genetics , Interleukin-15/immunology , Interleukin-2/genetics , Interleukin-2/immunology , Interleukin-6/genetics , Interleukin-6/immunology , Lactoferrin/genetics , Lactoferrin/immunology , Lipocalin-2/genetics , Lipocalin-2/immunology , Male , Matrix Metalloproteinase 9/genetics , Matrix Metalloproteinase 9/immunology , Middle Aged , Multivariate Analysis , NF-kappa B/genetics , NF-kappa B/immunology
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