scholarly journals A Virus-Specific Immune Rheostat in the Immunome of Patients Recovering From Mild COVID-19

2021 ◽  
Vol 12 ◽  
Author(s):  
Joo Guan Yeo ◽  
Jing Yao Leong ◽  
Shi Huan Tay ◽  
Karen Donceras Nadua ◽  
Danielle E. Anderson ◽  
...  
Keyword(s):  
T Cells ◽  
Receptor Binding ◽  
Cell Subset ◽  
Peptide Pool ◽  
Regulatory Mechanisms ◽  
Receptor Binding Domain ◽  
Mass Cytometry ◽  
Recall Response ◽  
Immune Effector ◽  
Follicular Helper

An accurate depiction of the convalescent COVID-19 immunome will help delineate the immunological milieu crucial for disease resolution and protection. Using mass cytometry, we characterized the immune architecture in patients recovering from mild COVID-19. We identified a virus-specific immune rheostat composed of an effector T (Teff) cell recall response that is balanced by the enrichment of a highly specialized regulatory T (Treg) cell subset. Both components were reactive against a peptide pool covering the receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein. We also observed expansion of IFNγ+ memory CD4+ T cells and virus-specific follicular helper T (TFH) cells. Overall, these findings pinpoint critical immune effector and regulatory mechanisms essential for a potent, yet harmless resolution of COVID-19 infection.

scholarly journals Ontogeny of different subsets of yellow fever virus-specific circulatory CXCR5+ CD4+ T cells after yellow fever vaccination

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Quinn DeGottardi ◽  
Theresa J. Gates ◽  
Junbao Yang ◽  
Eddie A. James ◽  
Uma Malhotra ◽  
...  
Keyword(s):  
T Cells ◽  
Yellow Fever ◽  
Germinal Center ◽  
Yellow Fever Virus ◽  
Fever Virus ◽  
Mass Cytometry ◽  
Follicular Helper ◽  
Potential Biomarker ◽  
Yellow Fever Vaccination ◽  
The Relationship

Abstract Monitoring the frequency of circulatory CXCR5+ (cCXCR5+) CD4+ T cells in periphery blood provides a potential biomarker to draw inferences about T follicular helper (TFH) activity within germinal center. However, cCXCR5+ T cells are highly heterogeneous in their expression of ICOS, PD1 and CD38 and the relationship between different cCXCR5 subsets as delineated by these markers remains unclear. We applied class II tetramer reagents and mass cytometry to investigate the ontogeny of different subsets of cCXCR5+ T cell following yellow fever immunization. Through unsupervised analyses of mass cytometry data, we show yellow fever virus-specific cCXCR5 T cells elicited by vaccination were initially CD38+ICOS+PD1+, but then transitioned to become CD38+ICOS−PD1+ and CD38−ICOS−PD1+ before coming to rest as a CD38−ICOS−PD1− subset. These results imply that most antigen-specific cCXCR5+ T cells, including the CD38−ICOS−PD1− CXCR5+ T cells are derived from the CXCR5+CD38+ICOS+PD1+ subset, the subset that most resembles preTFH/TFH in the germinal center.

scholarly journals The function of follicular helper T cells is regulated by the strength of T cell antigen receptor binding

2009 ◽  
Vol 10 (4) ◽  
pp. 375-384 ◽  
Author(s):  
Nicolas Fazilleau ◽  
Louise J McHeyzer-Williams ◽  
Hugh Rosen ◽  
Michael G McHeyzer-Williams
Keyword(s):  
T Cells ◽  
T Cell ◽  
Receptor Binding ◽  
Antigen Receptor ◽  
Helper T Cells ◽  
Follicular Helper T Cells ◽  
T Cell Antigen Receptor ◽  
Cell Antigen Receptor ◽  
Cell Antigen ◽  
Follicular Helper

scholarly journals Delineation of an immunosuppressive gradient in hepatocellular carcinoma using high-dimensional proteomic and transcriptomic analyses

2017 ◽  
Vol 114 (29) ◽  
pp. E5900-E5909 ◽  
Author(s):  
Valerie Chew ◽  
Liyun Lai ◽  
Lu Pan ◽  
Chun Jye Lim ◽  
Juntao Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
Transcription Factor ◽  
T Cell ◽  
Tumor Antigens ◽  
Cell Subset ◽  
High Dimensional ◽  
Mass Cytometry ◽  
Chemotactic Gradient ◽  
Activation Status

The recent development of immunotherapy as a cancer treatment has proved effective over recent years, but the precise dynamics between the tumor microenvironment (TME), nontumor microenvironment (NTME), and the systemic immune system remain elusive. Here, we interrogated these compartments in hepatocellular carcinoma (HCC) using high-dimensional proteomic and transcriptomic analyses. By time-of-flight mass cytometry, we found that the TME was enriched in regulatory T cells (Tregs), tissue resident memory CD8+ T cells (TRMs), resident natural killer cells (NKRs), and tumor-associated macrophages (TAMs). This finding was also validated with immunofluorescence staining on Foxp3+CD4+ and PD-1+CD8+ T cells. Interestingly, Tregs and TRMs isolated from the TME expressed multiple markers for T-cell exhaustion, including PD-1, Lag-3, and Tim-3 compared with Tregs and TRMs isolated from the NTME. We found PD-1+ TRMs were the predominant T-cell subset responsive to anti–PD-1 treatment and significantly reduced in number with increasing HCC tumor progression. Furthermore, T-bet was identified as a key transcription factor, negatively correlated with PD-1 expression on memory CD8+ T cells, and the PD-1:T-bet ratio increased upon exposure to tumor antigens. Finally, transcriptomic analysis of tumor and adjacent nontumor tissues identified a chemotactic gradient for recruitment of TAMs and NKRs via CXCR3/CXCL10 and CCR6/CCL20 pathways, respectively. Taken together, these data confirm the existence of an immunosuppressive gradient across the TME, NTME, and peripheral blood in primary HCC that manipulates the activation status of tumor-infiltrating leukocytes and renders them immunocompromised against tumor cells. By understanding the immunologic composition of this gradient, more effective immunotherapeutics for HCC may be designed.

scholarly journals Single dose immunization with a COVID-19 DNA vaccine encoding a chimeric homodimeric protein targeting receptor binding domain (RBD) to antigen-presenting cells induces rapid, strong and long-lasting neutralizing IgG, Th1 dominated CD4+ T cells and strong CD8+ T cell responses in mice

2020 ◽  
Author(s):  
Gunnstein Norheim ◽  
Elisabeth Stubsrud ◽  
Lise Madelene Skullerud ◽  
Branislava Stankovic ◽  
Stalin Chellappa ◽  
...  
Keyword(s):  
T Cells ◽  
Single Dose ◽  
T Cell ◽  
Receptor Binding ◽  
T Cell Responses ◽  
Antigen Presenting Cells ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Cell Responses ◽  
Antigen Presenting

AbstractThe pandemic caused by the SARS-CoV-2 virus in 2020 has led to a global public health emergency, and non-pharmaceutical interventions required to limit the viral spread are severely affecting health and economies across the world. A vaccine providing rapid and persistent protection across populations is urgently needed to prevent disease and transmission. We here describe the development of novel COVID-19 DNA plasmid vaccines encoding homodimers consisting of a targeting unit that binds chemokine receptors on antigen-presenting cells (human MIP-1α /LD78β), a dimerization unit (derived from the hinge and CH3 exons of human IgG3), and an antigenic unit (Spike or the receptor-binding domain (RBD) from SARS-CoV-2). The candidate encoding the longest RBD variant (VB2060) demonstrated high secretion of a functional protein and induced rapid and dose-dependent RBD IgG antibody responses that persisted up to at least 3 months after a single dose of the vaccine in mice. Neutralizing antibody (nAb) titers against the live virus were detected from day 7 after one dose. All tested dose regimens reached titers that were higher or comparable to those seen in sera from human convalescent COVID-19 patients from day 28. T cell responses were detected already at day 7, and were subsequently characterized to be multifunctional CD8+ and Th1 dominated CD4+ T cells. Responses remained at sustained high levels until at least 3 months after a single vaccination, being further strongly boosted by a second vaccination at day 89. These findings, together with the simplicity and scalability of plasmid DNA manufacturing, safety data on the vaccine platform in clinical trials, low cost of goods, data indicating potential long term storage at +2° to 8°C and simple administration, suggests the VB2060 candidate is a promising second generation candidate to prevent COVID-19.

Multiparametric Analysis of Intra-Tumoral T-Cells in Hodgkin's Lymphoma Using Mass Cytometry (CyTOF)

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1438-1438
Author(s):  
Jose Villasboas Bisneto ◽  
Stephen M Ansell
Keyword(s):  
T Cells ◽  
Data Analysis ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Single Cell ◽  
Hodgkin Lymphoma ◽  
Cell Subset ◽  
Mass Cytometry ◽  
Mean Frequency

Abstract Classic Hodgkin lymphoma (cHL) is characterized by a rich non-malignant immune infiltrate. T-cells are key components of the antitumoral immune response and studies characterizing subsets in cHL have yielded conflicting results. Initial studies suggested a predominance of TH2-polarized CD4+ T-cells, thought to allow tumor progression due to exhaustion and hypofunctionality. More recent data contest these findings, supporting the theory of tumor progression through evasion from a TH1-rich infiltrate that is potentially functional. The role of tumor evasion in cHL has been highlighted by compelling early clinical data with the use of PD-1 blockade in patients with advanced disease. A similar trial in patients with non-Hodgkin lymphoma (NHL) yielded far more modest results. Intrinsic differences in T-cell subpopulations in the tumor microenvironment may correlate to response to immune checkpoint inhibitor therapy. CyTOF or mass cytometry is a platform able to evaluate more than 45 simultaneous parameters on a single-cell level using nonradioactive nonbiological isotopes tagged to monoclonal antibodies. Measurements are made based on mass spectrometry, avoiding the hurdles of interference and spectral overlap experienced with fluorochromes. This constitutes an ideal tool for the study of the tumor microenvironment given its ability to assess a large number of parameters and resolve differences in a heterogeneous population. We hypothesize that the phenotype of intratumoral lymphocytes in cHL identifies T-cells that can effectively eradicate malignant cells. To test this hypothesis, we compared the phenotype of intratumoral T-cells in cHL to that of NHL and nodular lymphocyte-predominant Hodgkin Lymphoma (nlpHL). Tonsil and hyperplastic lymph node (LN) tissues were used as normal controls. Single-cell suspensions created from tumor specimens were stained with a metal-tagged antibody panel containing 31 surface markers and acquired on CyTOF. Multiparametric data analysis was performed on Cytobank using spanning-tree progression analysis of density-normalized events (SPADE) and t-Distributed Stochastic Neighbor Embedding (viSNE) algorithms. Inferential statistical analyses were performed with JMP®, Version 10.0.0 (SAS Institute Inc., Cary, NC, 1989-2007) using two-tailed tests and a 95% confidence interval. Cell subsets are expressed as percentages of parent population (CD45+CD3+CD19-). A total of 10 samples were studied (4 cHL, 1 nlpHL, 3 NHL, 1 tonsil, 1 LN). The total T-cell population ranged from 30.52 to 67.05% in cHL and 15.36 to 47% in NHL compared to 4.02% and 24.58% in tonsil and LN respectively. The CD4+ T-cell subset ranged from 58.05 to 35.3% in cHL, 50.03 to 82.61% in NHL and corresponded to 82.74% and 87.07% in tonsil and LN respectively. SPADE analysis identified two areas of asymmetric frequency of events amongst samples (figure 1 and 2). The CD4+ Tnaive subset (CD4+CD45RA+CCR7+) ranged from 7.8 to 31.2% of total T-cells in cHL compared to 10.7% in nlpHL, 0.17 to 3.02% in NHL and 6.2 to 6.7% in controls. The pooled mean frequency of CD4+ Tnaive subset was significantly higher in HL (cHL + nlpHL) compared to NHL (14.3% vs. 1.55%; p<0.05; figure 3A). The regulatory T-cell subset (Treg; CD25+CCR4+) ranged from 0.49 to 1.84% of total T-cells in HL compared to 9.3 to 21.04% in NHL, and 4.45 to 8.28% in controls. The pooled mean frequency of the Treg subset was significantly smaller in HL compared to NHL (1.28% vs. 16.23%; p<0.05; figure 3B). Our data supports the use of mass cytometry as a platform to study the tumor microenvironment in B-cell lymphomas. Multiparametric data analysis revealed significant differences in the intratumoral T-cell population between HL and NHL samples, namely in the CD4+ Tnaive and Treg subsets. Further validation in a larger sample is underway and will include panels to evaluate intracellular cytokine production and cell signaling pathways. Correlation between specific intratumoral T-cell phenotypic signatures and clinical outcomes may identify prognostic and predictive characteristics and provide insight to mechanisms of resistance to immunotherapy. Disclosures No relevant conflicts of interest to declare.

scholarly journals Addendum: The function of follicular helper T cells is regulated by the strength of T cell antigen receptor binding

2011 ◽  
Vol 12 (4) ◽  
pp. 362-362
Author(s):  
Nicolas Fazilleau ◽  
Louise J McHeyzer-Williams ◽  
Hugh Rosen ◽  
Michael G McHeyzer-Williams
Keyword(s):  
T Cells ◽  
T Cell ◽  
Receptor Binding ◽  
Antigen Receptor ◽  
Helper T Cells ◽  
Follicular Helper T Cells ◽  
T Cell Antigen Receptor ◽  
Cell Antigen Receptor ◽  
Cell Antigen ◽  
Follicular Helper

scholarly journals Follicular Regulatory T Cells Are Highly Permissive to R5-Tropic HIV-1

2017 ◽  
Vol 91 (17) ◽  
Author(s):  
Shannon M. Miller ◽  
Brodie Miles ◽  
Kejun Guo ◽  
Joy Folkvord ◽  
Amie L. Meditz ◽  
...  
Keyword(s):  
T Cells ◽  
Ex Vivo ◽  
Cell Subset ◽  
Viral Proteins ◽  
Ki67 Expression ◽  
Lymphoid Follicles ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Hiv 1

ABSTRACT Follicular regulatory T (TFR) cells are a subset of CD4+ T cells in secondary lymphoid follicles. TFR cells were previously included in the follicular helper T (TFH) cell subset, which consists of cells that are highly permissive to HIV-1. The permissivity of TFR cells to HIV-1 is unknown. We find that TFR cells are more permissive than TFH cells to R5-tropic HIV-1 ex vivo. TFR cells expressed more CCR5 and CD4 and supported higher frequencies of viral fusion. Differences in Ki67 expression correlated with HIV-1 replication. Inhibiting cellular proliferation reduced Ki67 expression and HIV-1 replication. Lymph node cells from untreated HIV-infected individuals revealed that TFR cells harbored the highest concentrations of HIV-1 RNA and highest levels of Ki67 expression. These data demonstrate that TFR cells are highly permissive to R5-tropic HIV-1 both ex vivo and in vivo. This is likely related to elevated CCR5 levels combined with a heightened proliferative state and suggests that TFR cells contribute to persistent R5-tropic HIV-1 replication in vivo. IMPORTANCE In chronic, untreated HIV-1 infection, viral replication is concentrated in secondary lymphoid follicles. Within secondary lymphoid follicles, follicular helper T (TFH) cells have previously been shown to be highly permissive to HIV-1. Recently, another subset of T cells in secondary lymphoid follicles was described, follicular regulatory T (TFR) cells. These cells share some phenotypic characteristics with TFH cells, and studies that showed that TFH cells are highly permissive to HIV-1 included TFR cells in their definition of TFH cells. The permissivity of TFR cells to HIV-1 has not previously been described. Here, we show that TFR cells are highly permissive to HIV-1 both ex vivo and in vivo. The expression of Ki67, a marker of proliferative capacity, is predictive of expression of viral proteins, and downregulating Ki67 leads to concurrent decreases in expression of viral proteins. Our study provides new insight into HIV-1 replication and a potential new cell type to target for future treatment.

scholarly journals Vaccination establishes clonal relatives of germinal center T cells in the blood of humans

2017 ◽  
Vol 214 (7) ◽  
pp. 2139-2152 ◽  
Author(s):  
Antje Heit ◽  
Frank Schmitz ◽  
Sarah Gerdts ◽  
Britta Flach ◽  
Miranda S. Moore ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Germinal Center ◽  
Cell Subset ◽  
Cell Receptor ◽  
B Cell Differentiation ◽  
Booster Immunization ◽  
Receptor Repertoire ◽  
Follicular Helper ◽  
Antibody Induction

Germinal center T follicular helper cells (GCTfh) in lymphatic tissue are critical for B cell differentiation and protective antibody induction, but whether GCTfh establish clonal derivatives as circulating memory T cells is less understood. Here, we used markers expressed on GCTfh, CXCR5, PD1, and ICOS, to identify potential circulating CXCR5+CD4+ Tfh-like cells (cTfh) in humans, and investigated their functional phenotypes, diversity, and ontogeny in paired donor blood and tonsils, and in blood after vaccination. Based on T cell receptor repertoire analysis, we found that PD-1–expressing cTfh and tonsillar GCTfh cells were clonally related. Furthermore, an activated, antigen-specific PD1+ICOS+ cTfh subset clonally expanded after booster immunization whose frequencies correlated with vaccine-specific serum IgG; these phenotypically resembled GCTfh, and were clonally related to a resting PD1+ICOS− CD4+ memory T cell subset. Thus, we postulate that vaccination establishes clonal relatives of GCTfh within the circulating memory CD4+CXCR5+PD1+ T cell pool that expand upon reencounter of their cognate antigen.

scholarly journals A Murine CD8+ T Cell Epitope Identified in the Receptor-Binding Domain of the SARS-CoV-2 Spike Protein

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 641
Author(s):  
Jihyun Yang ◽  
Eunjin Kim ◽  
Jong-Soo Lee ◽  
Haryoung Poo
Keyword(s):  
T Cell ◽  
Receptor Binding ◽  
Cytotoxic T Lymphocyte ◽  
Cell Epitope ◽  
Peptide Pool ◽  
Cd8 T Cell ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Lymphocyte Activity

The ongoing COVID-19 pandemic caused by SARS-CoV-2 has posed a devastating threat worldwide. The receptor-binding domain (RBD) of the spike protein is one of the most important antigens for SARS-CoV-2 vaccines, while the analysis of CD8 cytotoxic T lymphocyte activity in preclinical studies using mouse models is critical for evaluating vaccine efficacy. Here, we immunized C57BL/6 wild-type mice and transgenic mice expressing human angiotensin-converting enzyme 2 (ACE2) with the SARS-CoV-2 RBD protein to evaluate the IFN-γ-producing T cells in the splenocytes of the immunized mice using an overlapping peptide pool by an enzyme-linked immunospot assay and flow cytometry. We identified SARS-CoV-2 S395–404 as a major histocompatibility complex (MHC) class I-restricted epitope for the RBD-specific CD8 T cell responses in C57BL/6 mice.

scholarly journals CD4+CCR6+ T cells dominate the BCG-induced transcriptional signature

2021 ◽  
Author(s):  
Akul Singhania ◽  
Paige Dubelko ◽  
Rebecca Kuan ◽  
William D Chronister ◽  
Kaylin Muskat ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Immune Responses ◽  
Cd4 T Cells ◽  
Cellular Response ◽  
Cell Subset ◽  
Peptide Pool ◽  
Dna Methylome ◽  
Bcg Vaccination ◽  
Tcr Repertoire

The century-old Mycobacterium bovis Bacillus Calmette-Guerin (BCG) remains the only licensed vaccine against tuberculosis (TB). Despite this, there is still a lot to learn about the immune response induced by BCG, both in terms of phenotype and specificity. Here, we investigated immune responses in adult individuals pre and 8 months post BCG vaccination. We specifically determined changes in gene expression, cell subset composition, DNA methylome, and the TCR repertoire induced in PBMCs and CD4 memory T cells associated with antigen stimulation by either BCG or a Mycobacterium tuberculosis (Mtb)-derived peptide pool. Following BCG vaccination, we observed increased frequencies of CCR6+ CD4 T cells, which includes both Th1* and Th17 subsets, and mucosal associated invariant T cells (MAITs). A large number of immune response genes and pathways were upregulated post BCG vaccination with similar patterns observed in both PBMCs and memory CD4 T cells, thus suggesting a substantial role for CD4 T cells in the cellular response to BCG. These upregulated genes and associated pathways were also reflected in the DNA methylome. We described both qualitative and quantitative changes in the BCG-specific TCR repertoire post vaccination, and importantly found evidence for similar TCR repertoires across different subjects. The immune signatures defined herein can be used to track and further characterize immune responses induced by BCG, and can serve as reference for benchmarking novel vaccination strategies.

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