scholarly journals Dynamic blood single-cell immune responses in patients with COVID-19

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Lulin Huang ◽  
Yi Shi ◽  
Bo Gong ◽  
Li Jiang ◽  
Zhixin Zhang ◽  
...  

AbstractThe 2019 coronavirus disease (COVID-19) outbreak caused by the SARS-CoV-2 virus is an ongoing global health emergency. However, the virus’ pathogenesis remains unclear, and there is no cure for the disease. We investigated the dynamic changes of blood immune response in patients with COVID-19 at different stages by using 5’ gene expression, T cell receptor (TCR), and B cell receptors (BCR) V(D)J transcriptome analysis at a single-cell resolution. We obtained single-cell mRNA sequencing (scRNA-seq) data of 341,420 peripheral blood mononuclear cells (PBMCs) and 185,430 clonotypic T cells and 28,802 clonotypic B cells from 25 samples of 16 patients with COVID-19 for dynamic studies. In addition, we used three control samples. We found expansion of dendritic cells (DCs), CD14+ monocytes, and megakaryocytes progenitor cells (MP)/platelets and a reduction of naïve CD4+ T lymphocytes in patients with COVID-19, along with a significant decrease of CD8+ T lymphocytes, and natural killer cells (NKs) in patients in critical condition. The type I interferon (IFN-I), mitogen-activated protein kinase (MAPK), and ferroptosis pathways were activated while the disease was active, and recovered gradually after patient conditions improved. Consistent with this finding, the mRNA level of IFN-I signal-induced gene IFI27 was significantly increased in patients with COVID-19 compared with that of the controls in a validation cohort that included 38 patients and 35 controls. The concentration of interferon-α (IFN-α) in the serum of patients with COVID-19 increased significantly compared with that of the controls in an additional cohort of 215 patients with COVID-19 and 106 controls, further suggesting the important role of the IFN-I pathway in the immune response of COVID-19. TCR and BCR sequences analyses indicated that patients with COVID-19 developed specific immune responses against SARS-CoV-2 antigens. Our study reveals a dynamic landscape of human blood immune responses to SARS-CoV-2 infection, providing clues for therapeutic potentials in treating COVID-19.

2021 ◽  
Author(s):  
Emily Stephenson ◽  
◽  
Gary Reynolds ◽  
Rachel A. Botting ◽  
Fernando J. Calero-Nieto ◽  
...  

AbstractAnalysis of human blood immune cells provides insights into the coordinated response to viral infections such as severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19). We performed single-cell transcriptome, surface proteome and T and B lymphocyte antigen receptor analyses of over 780,000 peripheral blood mononuclear cells from a cross-sectional cohort of 130 patients with varying severities of COVID-19. We identified expansion of nonclassical monocytes expressing complement transcripts (CD16+C1QA/B/C+) that sequester platelets and were predicted to replenish the alveolar macrophage pool in COVID-19. Early, uncommitted CD34+ hematopoietic stem/progenitor cells were primed toward megakaryopoiesis, accompanied by expanded megakaryocyte-committed progenitors and increased platelet activation. Clonally expanded CD8+ T cells and an increased ratio of CD8+ effector T cells to effector memory T cells characterized severe disease, while circulating follicular helper T cells accompanied mild disease. We observed a relative loss of IgA2 in symptomatic disease despite an overall expansion of plasmablasts and plasma cells. Our study highlights the coordinated immune response that contributes to COVID-19 pathogenesis and reveals discrete cellular components that can be targeted for therapy.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alex R Schuurman ◽  
Tom DY Reijnders ◽  
Anno Saris ◽  
Ivan Ramirez Moral ◽  
Michiel Schinkel ◽  
...  

The exact immunopathophysiology of community-acquired pneumonia (CAP) caused by SARS-CoV-2 (COVID-19) remains clouded by a general lack of relevant disease controls. The scarcity of single-cell investigations in the broader population of patients with CAP renders it difficult to distinguish immune features unique to COVID-19 from the common characteristics of a dysregulated host response to pneumonia. We performed integrated single-cell transcriptomic and proteomic analyses in peripheral blood mononuclear cells from a matched cohort of eight patients with COVID-19, eight patients with CAP caused by Influenza A or other pathogens, and four non-infectious control subjects. Using this balanced, multi-omics approach, we describe shared and diverging transcriptional and phenotypic patterns—including increased levels of type I interferon-stimulated natural killer cells in COVID-19, cytotoxic CD8 T EMRA cells in both COVID-19 and influenza, and distinctive monocyte compositions between all groups—and thereby expand our understanding of the peripheral immune response in different etiologies of pneumonia.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4650-4650
Author(s):  
Christin Flechsig ◽  
Yasemin Suezer ◽  
Markus Kapp ◽  
Gerd Sutter ◽  
Hermann Einsele ◽  
...  

Abstract Abstract 4650 Introduction MVA is one of the most promising vaccine candidates for infectious diseases as well as for malignancies. Astonishingly, little information exists about the mechanism by which immune responses to MVA are generated. It was shown that among leukocytes - which are essential for the generation of cellular and humoral immune responses - APCs like dendritic cells, monocytes and B cells are preferentially infected. But little is known about the effects on APCs. Therefore we wanted to analyze in more detail the general effects of MVA infections on different immune cells. Methods Primary human peripheral blood mononuclear cells (PBMCs) and isolated leukocyte populations in particular monocyte derived DCs, monocytes and B cells were infected with (wildtype) wtMVA or MVA-gfp (green fluorescent protein) to verify the infection. Subsequently changes in surface markers and cytokine expression were assessed. Results Among PBMCs and specific isolated leukocyte populations, monocytes, DCs and B cells were most susceptible to MVA infection. NK cells showed a lower and T cells a very low infection rate. Surprisingly, selected monocytes were less susceptible to MVA as compared to unselected ones. This phenomenon is due to phagocytosis of other infected PBMCs by monocytes. Furthermore we could show that MVA causes a downregulation of CD14 on iDCs and monocytes as well as of CD25, CD80, and CD86 on B cells. Furthermore, there was a slight downregulation of CD1a on iDCs and mDCs and of CD80 on iDCs. On the other hand MVA caused an upregulation of HLA-DR on monocytes and additionally a slight upregulation of CD40 on iDCs. Moreover, MVA evoked a slight upregulation of CD83 on iDCs but a slight downregulation on mDCs. Above all, we could demonstrate that MVA induces an upregulation of CXCL10 in iDCs, mDCs, monocytes, and B cells, and an upregulation of TNFα, IL-6, and IL-12p70 in iDCs, mDCs, and monocytes. In addition, we revealed a downregulation of CXCL8 in monocytes as well as of IL-β in B cells. Conclusions These results suggest that MVA induces a Th1-polarized immune response in APCs. Thus, MVA seems to be an appropriate vaccine vector for antiviral immunotherapy of stem cell transplant recipients. Disclosures: No relevant conflicts of interest to declare.


Author(s):  
Suji Kim ◽  
Hyun-Eui Park ◽  
Woo Bin Park ◽  
Seo Yihl Kim ◽  
Hong-Tae Park ◽  
...  

Mycobacterium avium, an opportunistic intracellular pathogen, is a member of the non-tuberculous mycobacteria species. M. avium causes respiratory disease in immunosuppressed individuals and a wide range of animals, including companion dogs and cats. In particular, the number of infected companion dogs has increased, although the underlying mechanism of M. avium pathogenesis in dogs has not been studied. Therefore, in the present study, the host immune response against M. avium in dogs was investigated by transcriptome analysis of canine peripheral blood mononuclear cells. M. avium was shown to induce different immune responses in canine peripheral blood mononuclear cells at different time points after infection. The expression of Th1-associated genes occurred early during M. avium infection, while that of Th17-associated genes increased after 12 h. In addition, the expression of apoptosis-related genes decreased and the abundance of intracellular M. avium increased in monocyte-derived macrophages after infection for 24 h. These results reveal the M. avium induces Th17 immune response and avoids apoptosis in infected canine cells. As the number of M. avium infection cases increases, the results of the present study will contribute to a better understanding of host immune responses to M. avium infection in companion dogs.


2009 ◽  
Vol 83 (11) ◽  
pp. 5890-5903 ◽  
Author(s):  
Sylvain Baize ◽  
Philippe Marianneau ◽  
Philippe Loth ◽  
Stéphanie Reynard ◽  
Alexandra Journeaux ◽  
...  

ABSTRACT Lassa virus causes a hemorrhagic fever endemic in West Africa. The pathogenesis and the immune responses associated with the disease are poorly understood, and no vaccine is available. We followed virological, pathological, and immunological markers associated with fatal and nonfatal Lassa virus infection of cynomolgus monkeys. The clinical picture was characterized by fever, weight loss, depression, and acute respiratory syndrome. Transient thrombocytopenia and lymphopenia, lymphadenopathy, splenomegaly, infiltration of mononuclear cells, and alterations of the liver, lungs, and endothelia were observed. Survivors exhibited fewer lesions and a lower viral load than nonsurvivors. Although all animals developed strong humoral responses, antibodies appeared more rapidly in survivors and were directed against GP1, GP2, and NP. Type I interferons were detected early after infection in survivors but only during the terminal stages in fatalities. The mRNAs for CXCL10 (IP-10) and CXCL11 (I-TAC) were abundant in peripheral blood mononuclear cells and lymph nodes from infected animals, but plasma interleukin-6 was detected only in fatalities. In survivors, high activated-monocyte counts were followed by a rise in the total number of circulating monocytes. Activated T lymphocytes circulated in survivors, whereas T-cell activation was low and delayed in fatalities. In vitro stimulation with inactivated Lassa virus induced activation of T lymphocytes from all infected monkeys, but only lymphocytes from survivors proliferated. Thus, early and strong immune responses and control of viral replication were associated with recovery, whereas fatal infection was characterized by major alterations of the blood formula and, in organs, weak immune responses and uncontrolled viral replication.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dijoia B. Darden ◽  
Xiaoru Dong ◽  
Maigan A. Brusko ◽  
Lauren Kelly ◽  
Brittany Fenner ◽  
...  

BackgroundWith the successful implementation of the Surviving Sepsis Campaign guidelines, post-sepsis in-hospital mortality to sepsis continues to decrease. Those who acutely survive surgical sepsis will either rapidly recover or develop a chronic critical illness (CCI). CCI is associated with adverse long-term outcomes and 1-year mortality. Although the pathobiology of CCI remains undefined, emerging evidence suggests a post-sepsis state of pathologic myeloid activation, inducing suboptimal lymphopoiesis and erythropoiesis, as well as downstream leukocyte dysfunction. Our goal was to use single-cell RNA sequencing (scRNA-seq) to perform a detailed transcriptomic analysis of lymphoid-derived leukocytes to better understand the pathology of late sepsis.MethodsA mixture of whole blood myeloid-enriched and Ficoll-enriched peripheral blood mononuclear cells from four late septic patients (post-sepsis day 14-21) and five healthy subjects underwent Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq).ResultsWe identified unique transcriptomic patterns for multiple circulating immune cell subtypes, including B- and CD4+, CD8+, activated CD4+ and activated CD8+ T-lymphocytes, as well as natural killer (NK), NKT, and plasmacytoid dendritic cells in late sepsis patients. Analysis demonstrated that the circulating lymphoid cells maintained a transcriptome reflecting immunosuppression and low-grade inflammation. We also identified transcriptomic differences between patients with bacterial versus fungal sepsis, such as greater expression of cytotoxic genes among CD8+ T-lymphocytes in late bacterial sepsis.ConclusionCirculating non-myeloid cells display a unique transcriptomic pattern late after sepsis. Non-myeloid leukocytes in particular reveal a host endotype of inflammation, immunosuppression, and dysfunction, suggesting a role for precision medicine-guided immunomodulatory therapy.


Science ◽  
2020 ◽  
Vol 369 (6508) ◽  
pp. 1210-1220 ◽  
Author(s):  
Prabhu S. Arunachalam ◽  
Florian Wimmers ◽  
Chris Ka Pun Mok ◽  
Ranawaka A. P. M. Perera ◽  
Madeleine Scott ◽  
...  

Coronavirus disease 2019 (COVID-19) represents a global crisis, yet major knowledge gaps remain about human immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We analyzed immune responses in 76 COVID-19 patients and 69 healthy individuals from Hong Kong and Atlanta, Georgia, United States. In the peripheral blood mononuclear cells (PBMCs) of COVID-19 patients, we observed reduced expression of human leukocyte antigen class DR (HLA-DR) and proinflammatory cytokines by myeloid cells as well as impaired mammalian target of rapamycin (mTOR) signaling and interferon-α (IFN-α) production by plasmacytoid dendritic cells. By contrast, we detected enhanced plasma levels of inflammatory mediators—including EN-RAGE, TNFSF14, and oncostatin M—which correlated with disease severity and increased bacterial products in plasma. Single-cell transcriptomics revealed a lack of type I IFNs, reduced HLA-DR in the myeloid cells of patients with severe COVID-19, and transient expression of IFN-stimulated genes. This was consistent with bulk PBMC transcriptomics and transient, low IFN-α levels in plasma during infection. These results reveal mechanisms and potential therapeutic targets for COVID-19.


2020 ◽  
Author(s):  
Shuliang Chen ◽  
Sameer Kumar ◽  
Nagaraja Tirumuru ◽  
Jennifer L. Welch ◽  
Lulu Hu ◽  
...  

AbstractN6-methyladenosine (m6A) is a prevalent RNA modification that plays a key role in regulating eukaryotic cellular mRNA functions. RNA m6A modification is regulated by two groups of cellular proteins, writers and erasers that add or remove m6A, respectively. HIV-1 RNA contains m6A modifications that modulate viral infection and gene expression in cells. However, it remains unclear whether m6A modifications of HIV-1 RNA modulate innate immune responses in cells or HIV-1-infected individuals. Here we show that m6A modification of HIV-1 RNA suppresses the expression of antiviral cytokine type-I interferon (IFN-I) in human monocytic cells. Transfection of differentiated monocytic cells with HIV-1 RNA fragments containing a single m6A-modification significantly reduced IFN-I mRNA expression relative to their unmodified RNA counterparts. We generated HIV-1 with altered RNA m6A levels by manipulating the expression of the m6A erasers or pharmacological inhibition of m6A addition in virus-producing cells. RNA transfection and viral infection of differentiated monocytic cells demonstrated that HIV-1 RNA with decreased m6A levels enhanced IFN-I expression, whereas HIV-1 RNA with increased m6A modifications had opposite effects. Our mechanistic studies revealed that m6A of HIV-1 RNA escaped the RIG-I-mediated RNA sensing and activation of the transcription factors IRF3 and IRF7 that drive IFN-I gene expression. Moreover, RNA of peripheral blood mononuclear cells from HIV-1 viremic patients showed increased m6A levels that correlated with increased IFN-I mRNA expression compared to levels from HIV-1-suppressed patients on antiretroviral therapy. Together, our results suggest that RNA m6A modifications regulate viral replication and antiviral innate immune responses in HIV-1-infected individuals.Author SummaryHIV-1 is known as a weak inducer of antiviral cytokines including IFN-I, but it is unclear how HIV-1 evades innate immunity. Different types of RNA modifications including m6A within the HIV-1 genome modulate viral replication; however, the role of m6A modifications of HIV-1 RNA in regulating innate immune responses remains elusive. In this study, we found that HIV-1 RNA modified with m6A suppresses the expression of IFN-I in differentiated monocytic cells by avoiding innate immune detection of viral RNA mediated by RIG-I, an RNA sensor in host cells. We also observed significantly increased RNA m6A modifications of peripheral blood mononuclear cells from HIV-1 viremic patients compared to virally suppressed patients on combined antiretroviral therapy, suggesting a functional link between m6A modifications and antiretroviral treatment. Investigating the functions of m6A modifications of HIV-1 RNA in regulating innate immune sensing and IFN-I induction in monocytic cells can help understand the mechanisms of HIV-1 persistence.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhen Wang ◽  
Lijian Xie ◽  
Guohui Ding ◽  
Sirui Song ◽  
Liqin Chen ◽  
...  

AbstractKawasaki disease (KD) is the most common cause of acquired heart disease in children in developed countries. Although functional and phenotypic changes of immune cells have been reported, a global understanding of immune responses underlying acute KD is unclear. Here, using single-cell RNA sequencing, we profile peripheral blood mononuclear cells from seven patients with acute KD before and after intravenous immunoglobulin therapy and from three age-matched healthy controls. The most differentially expressed genes are identified in monocytes, with high expression of pro-inflammatory mediators, immunoglobulin receptors and low expression of MHC class II genes in acute KD. Single-cell RNA sequencing and flow cytometry analyses, of cells from an additional 16 KD patients, show that although the percentage of total B cells is substantially decreased after therapy, the percentage of plasma cells among the B cells is significantly increased. The percentage of CD8+ T cells is decreased in acute KD, notably effector memory CD8+ T cells compared with healthy controls. Oligoclonal expansions of both B cell receptors and T cell receptors are observed after therapy. We identify biological processes potentially underlying the changes of each cell type. The single-cell landscape of both innate and adaptive immune responses provides insights into pathogenesis and therapy of KD.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Karol Nienałtowski ◽  
Rachel E. Rigby ◽  
Jarosław Walczak ◽  
Karolina E. Zakrzewska ◽  
Edyta Głów ◽  
...  

AbstractAlthough we can now measure single-cell signaling responses with multivariate, high-throughput techniques our ability to interpret such measurements is still limited. Even interpretation of dose–response based on single-cell data is not straightforward: signaling responses can differ significantly between cells, encompass multiple signaling effectors, and have dynamic character. Here, we use probabilistic modeling and information-theory to introduce fractional response analysis (FRA), which quantifies changes in fractions of cells with given response levels. FRA can be universally performed for heterogeneous, multivariate, and dynamic measurements and, as we demonstrate, quantifies otherwise hidden patterns in single-cell data. In particular, we show that fractional responses to type I interferon in human peripheral blood mononuclear cells are very similar across different cell types, despite significant differences in mean or median responses and degrees of cell-to-cell heterogeneity. Further, we demonstrate that fractional responses to cytokines scale linearly with the log of the cytokine dose, which uncovers that heterogeneous cellular populations are sensitive to fold-changes in the dose, as opposed to additive changes.


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