scholarly journals T Cell Interactions in Mycobacterial Granulomas: Non-Specific T Cells Regulate Mycobacteria-Specific T Cells in Granulomatous Lesions

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3285
Author(s):  
Dominic O. Co ◽  
Laura H. Hogan ◽  
Jozsef Karman ◽  
Melinda Herbath ◽  
Zsuzsanna Fabry ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Phase ◽  
Inhibitory Effect ◽  
Cell System ◽  
Bacterial Antigen ◽  
Wild Type ◽  
Cell Repertoire ◽  
Cytokines And Chemokines ◽  
Wild Type Phenotype

Infections with pathogenic mycobacteria are controlled by the formation of a unique structure known as a granuloma. The granuloma represents a host–pathogen interface where bacteria are killed and confined by the host response, but also where bacteria persist. Previous work has demonstrated that the T cell repertoire is heterogenous even at the single granuloma level. However, further work using pigeon cytochrome C (PCC) epitope-tagged BCG (PCC-BCG) and PCC-specific 5CC7 RAG−/− TCR transgenic (Tg) mice has demonstrated that a monoclonal T cell population is able to control infection. At the chronic stage of infection, granuloma-infiltrating T cells remain highly activated in wild-type mice, while T cells in the monoclonal T cell mice are anergic. We hypothesized that addition of an acutely activated non-specific T cell to the monoclonal T cell system could recapitulate the wild-type phenotype. Here we report that activated non-specific T cells have access to the granuloma and deliver a set of cytokines and chemokines to the lesions. Strikingly, non-specific T cells rescue BCG-specific T cells from anergy and enhance the function of BCG-specific T cells in the granuloma in the chronic phase of infection when bacterial antigen load is low. In addition, we find that these same non-specific T cells have an inhibitory effect on systemic BCG-specific T cells. Taken together, these data suggest that T cells non-specific for granuloma-inducing agents can alter the function of granuloma-specific T cells and have important roles in mycobacterial immunity and other granulomatous disorders.

scholarly journals Cross-presentation of a TAP-independent signal peptide induces CD8 T immunity to escaped cancers but necessitates anchor replacement

2021 ◽  
Author(s):  
Koen A. Marijt ◽  
Lisa Griffioen ◽  
Laura Blijleven ◽  
Sjoerd. H. van der Burg ◽  
Thorbald van Hall
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cancer Cells ◽  
Cd8 T Cells ◽  
Antigen Processing ◽  
Signal Sequence ◽  
Cell Repertoire ◽  
Cross Presentation ◽  
Normal Tissues ◽  
Cell Immunity

AbstractCancer cells frequently display defects in their antigen-processing pathway and thereby evade CD8 T cell immunity. We described a novel category of cancer antigens, named TEIPP, that emerge on cancers with functional loss of the peptide pump TAP. TEIPPs are non-mutated neoantigens despite their ‘self’ origin by virtue of their absence on normal tissues. Here, we describe the development of a synthetic long peptide (SLP) vaccine for the most immunogenic TEIPP antigen identified thus far, derived from the TAP-independent LRPAP1 signal sequence. LRPAP121–30-specific CD8 T cells were present in blood of all tested healthy donors as well as patients with non-small cell lung adenocarcinoma. SLPs with natural flanking, however, failed to be cross-presented by monocyte-derived dendritic cells. Since the C-terminus of LRPAP121–30 is an unconventional and weakly binding serine (S), we investigated if replacement of this anchor would result in efficient cross-presentation. Exchange into a valine (V) resulted in higher HLA-A2 binding affinity and enhanced T cell stimulation. Importantly, CD8 T cells isolated using the V-variant were able to bind tetramers with the natural S-variant and respond to TAP-deficient cancer cells. A functional screen with an array of N-terminal and C-terminal extended SLPs pointed at the 24-mer V-SLP, elongated at the N-terminus, as most optimal vaccine candidate. This SLP was efficiently cross-presented and consistently induced a strong polyclonal LRPAP121–30-specific CD8 T cells from the endogenous T cell repertoire. Thus, we designed a TEIPP SLP vaccine from the LRPAP1 signal sequence ready for validation in clinical trials.

scholarly journals T cell–specific STAT3 deficiency abrogates lupus nephritis

Lupus ◽  
2019 ◽  
Vol 28 (12) ◽  
pp. 1468-1472 ◽  
Author(s):  
N Yoshida ◽  
F He ◽  
V C Kyttaris
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Cell Responses ◽  
Cytokines And Chemokines ◽  
Novel Approach ◽  
Cell Tissue ◽  
External Stimuli

Signal transducer and activator of transcription (STAT) 3 is a regulator of T-cell responses to external stimuli, such as pro-inflammatory cytokines and chemokines. We have previously shown that STAT3 is activated (phosphorylated) at high levels in systemic lupus erythematosus (SLE) T cells and mediates chemokine-induced migration and T:B cell interactions. Stattic, a small molecular STAT3 inhibitor, can partially ameliorate lupus nephritis in mice. To understand the role of STAT3 better in T-cell pathophysiology in lupus nephritis and its potential as a treatment target, we silenced its expression in T cells using a cd4-driven CRE-Flox model. We found that lupus-prone mice that do not express STAT3 in T cells did not develop lymphadenopathy, splenomegaly, or glomerulonephritis. Moreover, the production of anti-dsDNA antibodies was decreased in these mice compared to controls. To dissect the mechanism, we also used a nephrotoxic serum model of nephritis. In this model, T cell–specific silencing of STAT3 resulted in amelioration of nephrotoxic serum-induced kidney damage. Taken together, our results suggest that in mouse models of autoimmune nephritis, T cell–specific silencing of STAT3 can hamper their ability to help B cells to produce autoantibodies and induce cell tissue infiltration. We propose that STAT3 inhibition in T cells represents a novel approach in the treatment of SLE and lupus nephritis in particular.

scholarly journals Polyclonal expansion of TCR Vbeta 21.3+ CD4+ and CD8+ T cells is a hallmark of Multisystem Inflammatory Syndrome in Children

2021 ◽  
Vol 6 (59) ◽  
pp. eabh1516
Author(s):  
Marion Moreews ◽  
Kenz Le Gouge ◽  
Samira Khaldi-Plassart ◽  
Rémi Pescarmona ◽  
Anne-Laure Mathieu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Expansion ◽  
Healthy Children ◽  
Antigenic Peptides ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Hla Dr ◽  
T Cell Expansion ◽  
Inflammatory Syndrome

Multiple Inflammatory Syndrome in Children (MIS-C) is a delayed and severe complication of SARS-CoV-2 infection that strikes previously healthy children. As MIS-C combines clinical features of Kawasaki disease and Toxic Shock Syndrome (TSS), we aimed to compare the immunological profile of pediatric patients with these different conditions. We analyzed blood cytokine expression, and the T cell repertoire and phenotype in 36 MIS-C cases, which were compared to 16 KD, 58 TSS, and 42 COVID-19 cases. We observed an increase of serum inflammatory cytokines (IL-6, IL-10, IL-18, TNF-α, IFNγ, CD25s, MCP1, IL-1RA) in MIS-C, TSS and KD, contrasting with low expression of HLA-DR in monocytes. We detected a specific expansion of activated T cells expressing the Vβ21.3 T cell receptor β chain variable region in both CD4 and CD8 subsets in 75% of MIS-C patients and not in any patient with TSS, KD, or acute COVID-19; this correlated with the cytokine storm detected. The T cell repertoire returned to baseline within weeks after MIS-C resolution. Vβ21.3+ T cells from MIS-C patients expressed high levels of HLA-DR, CD38 and CX3CR1 but had weak responses to SARS-CoV-2 peptides in vitro. Consistently, the T cell expansion was not associated with specific classical HLA alleles. Thus, our data suggested that MIS-C is characterized by a polyclonal Vβ21.3 T cell expansion not directed against SARS-CoV-2 antigenic peptides, which is not seen in KD, TSS and acute COVID-19.

scholarly journals A role for CD9 molecules in T cell activation.

1996 ◽  
Vol 184 (2) ◽  
pp. 753-758 ◽  
Author(s):  
X G Tai ◽  
Y Yashiro ◽  
R Abe ◽  
K Toyooka ◽  
C R Wood ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
Expression Cloning ◽  
Wild Type ◽  
Almost All ◽  
Antigen Presenting ◽  
Deficient Mice

Costimulation mediated by the CD28 molecule plays an important role in optimal activation of T cells. However, CD28-deficient mice can mount effective T cell-dependent immune responses, suggesting the existence of other costimulatory systems. In a search for other costimulatory molecules on T cells, we have developed a monoclonal antibody (mAb) that can costimulate T cells in the absence of antigen-presenting cells (APC). The molecule recognized by this mAb, 9D3, was found to be expressed on almost all mature T cells and to be a protein of approximately 24 kD molecular mass. By expression cloning, this molecule was identified as CD9, 9D3 (anti-CD9) synergized with suboptimal doses of anti-CD3 mAb in inducing proliferation by virgin T cells. Costimulation was induced by independent ligation of CD3 and CD9, suggesting that colocalization of these two molecules is not required for T cell activation. The costimulation by anti-CD9 was as potent as that by anti-CD28. Moreover, anti-CD9 costimulated in a CD28-independent way because anti-CD9 equally costimulated T cells from the CD28-deficient as well as wild-type mice. Thus, these results indicate that CD9 serves as a molecule on T cells that can deliver a potent CD28-independent costimulatory signal.

scholarly journals 762 A combination of functional biomarkers improves identification of the tumor-specific reactive T cell repertoire

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A810-A810
Author(s):  
Arianna Draghi ◽  
Katja Harbst ◽  
Inge Svane ◽  
Marco Donia
Keyword(s):  
T Cells ◽  
T Cell ◽  
De Novo ◽  
Autologous Tumor ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Simple Method ◽  
Functional Biomarkers

BackgroundDetecting the entire repertoire of tumor-specific reactive T cells is essential for investigating the broad range of T cell functions in the tumor-microenvironment. At present, assays identifying tumor-specific functional activation measure either upregulation of specific surface molecules, de novo production of the most common antitumor cytokines or mobilization of cytotoxic granules.MethodsIn this study, we combined transcriptomic analyses of tumor-specific reactive tumorinfiltrating lymphocytes (TILs), TIL-autologous tumor cell co-cultures and commonly used established detection protocols to develop an intracellular flow cytometry staining method encompassing simultaneous detection of intracellular CD137, de novo production of TNF and IFNy and extracellular mobilization of CD107a.ResultsThis approach enabled the identification of a larger fraction of tumor-specific reactive T cells in vitro compared to standard methods, revealing the existence of multiple distinct functional clusters of tumor-specific reactive TILs. Publicly available datasets of fresh tumor single-cell RNA-sequencing from four cancer types were investigated to confirm that these functional biomarkers identified distinct functional clusters forming the entire repertoire of tumor-specific reactive T cells in situ.ConclusionsIn conclusion, we describe a simple method using a combination of functional biomarkers that improves identification of the tumor-specific reactive T cell repertoire in vitro and in situ.

scholarly journals T cell receptor recognition of hybrid insulin peptides bound to HLA-DQ8

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mai T. Tran ◽  
Pouya Faridi ◽  
Jia Jia Lim ◽  
Yi Tian Ting ◽  
Goodluck Onwukwe ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Type I Diabetes ◽  
Binding Motif ◽  
Type I ◽  
Cell Repertoire ◽  
Islet Amyloid ◽  
Autoreactive T Cell ◽  
Β Chain

AbstractHLA-DQ8, a genetic risk factor in type I diabetes (T1D), presents hybrid insulin peptides (HIPs) to autoreactive CD4+ T cells. The abundance of spliced peptides binding to HLA-DQ8 and how they are subsequently recognised by the autoreactive T cell repertoire is unknown. Here we report, the HIP (GQVELGGGNAVEVLK), derived from splicing of insulin and islet amyloid polypeptides, generates a preferred peptide-binding motif for HLA-DQ8. HLA-DQ8-HIP tetramer+ T cells from the peripheral blood of a T1D patient are characterised by repeated TRBV5 usage, which matches the TCR bias of CD4+ T cells reactive to the HIP peptide isolated from the pancreatic islets of a patient with T1D. The crystal structure of three TRBV5+ TCR-HLA-DQ8-HIP complexes shows that the TRBV5-encoded TCR β-chain forms a common landing pad on the HLA-DQ8 molecule. The N- and C-termini of the HIP is recognised predominantly by the TCR α-chain and TCR β-chain, respectively, in all three TCR ternary complexes. Accordingly, TRBV5 + TCR recognition of HIP peptides might occur via a ‘polarised’ mechanism, whereby each chain within the αβTCR heterodimer recognises distinct origins of the spliced peptide presented by HLA-DQ8.

scholarly journals Distinct contributions of CD4+ T cell subsets in hepatic ischemia/reperfusion injury

2009 ◽  
Vol 296 (5) ◽  
pp. G1054-G1059 ◽  
Author(s):  
Satoshi Kuboki ◽  
Nozomu Sakai ◽  
Johannes Tschöp ◽  
Michael J. Edwards ◽  
Alex B. Lentsch ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Ischemia Reperfusion ◽  
Γδ T Cells ◽  
Nkt Cells ◽  
T Cell Subsets ◽  
Wild Type ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Helper T cells are known to mediate hepatic ischemia/reperfusion (I/R) injury. However, the precise mechanisms and subsets of CD4+ T cells that contribute to this injury are still controversial. Therefore, we sought to determine the contributions of different CD4+ T cell subsets during hepatic I/R injury. Wild-type, OT-II, or T cell receptor (TCR)-δ-deficient mice were subjected to 90 min of partial hepatic ischemia followed by 8 h of reperfusion. Additionally, wild-type mice were pretreated with anti-CD1d, -NK1.1, or -IL-2R-α antibodies before I/R injury. OT-II mice had diminished liver injury compared with wild-type mice, implicating that antigen-dependent activation of CD4+ T cells through TCRs is involved in hepatic I/R injury. TCR-δ knockout mice had decreased hepatic neutrophil accumulation, suggesting that γδ T cells regulate neutrophil recruitment. We found that natural killer T (NKT) cells, but not NK cells, contribute to hepatic I/R injury via CD1d-dependent activation of their TCRs, as depletion of NKT cells by anti-CD1d antibody or depletion of both NKT cells and NK cells by anti-NK1.1 attenuated liver injury. Although regulatory T cells (Treg) are known to suppress T cell-dependent inflammation, depletion of Treg cells had little effect on hepatic I/R injury. The data suggest that antigen-dependent activation of CD4+ T cells contributes to hepatic I/R injury. Among the subsets of CD4+ T cells, it appears that γδ T cells contribute to neutrophil recruitment and that NKT cells directly injure the liver. In contrast, NK cells and Treg have little effects on hepatic I/R injury.

scholarly journals Characterization of human cytomegalovirus peptide–specific CD8+ T-cell repertoire diversity following in vitro restimulation by antigen-pulsed dendritic cells

Blood ◽  
2002 ◽  
Vol 99 (1) ◽  
pp. 213-223 ◽  
Author(s):  
Karl Peggs ◽  
Stephanie Verfuerth ◽  
Arnold Pizzey ◽  
Jenni Ainsworth ◽  
Paul Moss ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Viral Replication ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Repertoire Diversity ◽  
Clonal Composition

Under conditions of impaired T-cell immunity, human cytomegalovirus (HCMV) can reactivate from lifelong latency, resulting in potentially fatal disease. A crucial role for CD8+ T cells has been demonstrated in control of viral replication, and high levels of HCMV-specific cytotoxic T-lymphocytes are seen in immunocompetent HCMV-seropositive individuals despite very low viral loads. Elucidation of the minimum portion of the anti-HCMV T-cell repertoire that is required to suppress viral replication requires further study of clonal composition. The ability of dendritic cells to take up and process exogenous viral antigen by constitutive macropinocytosis was used to study HCMV-specific T-cell memory in the absence of viral replication. The specificity and clonal composition of the CD8+ T-cell responses were evaluated using HLA tetrameric complexes and T-cell receptor β chain (TCRBV) spectratypic analyses. There was a skewed reactivity toward the matrix protein pp65, with up to 40-fold expansion of CD8+ T cells directed toward a single peptide-MHC combination. Individual expansions detected on TCRBV spectratype analysis were HCMV-specific and composed of single or highly restricted numbers of clones. There was preferential TCRBV gene usage (BV6.1/6.2, BV8, and BV13 in HLA-A*0201+ individuals) but lack of conservation of CDR3 length and junctional motifs between donors. While there was a spectrum of TCR repertoire diversity directed toward individual MHC-peptide combinations between donors, a relatively small number of clones appeared to predominate the response in each case. These data provide further insight into the range of anti-HCMV responses and will aid the design and monitoring of adoptive immunotherapy protocols.

Evaluation of vecabrutinib as a model for non-covalent BTK/ITK inhibition for treatment of chronic lymphocytic leukemia

Blood ◽  
2021 ◽  
Author(s):  
Billy Michael Chelliah Jebaraj ◽  
Annika Müller ◽  
Rashmi Priyadharshini Dheenadayalan ◽  
Sascha Endres ◽  
Philipp M. Roessner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Inhibitory Effect ◽  
Lymphocytic Leukemia ◽  
Transfer Model ◽  
Treatment Benefit ◽  
Btk Inhibitors

Covalent Bruton tyrosine kinase (BTK) inhibitors such as ibrutinib have proven to be highly beneficial in the treatment of chronic lymphocytic leukemia (CLL). Interestingly, the off-target inhibition of IL-2-inducible T-cell kinase (ITK) by ibrutinib may also play a role in modulating the tumor microenvironment, potentially enhancing the treatment benefit. However, resistance to covalently binding BTK inhibitors can develop by a mutation in cysteine 481 of BTK (C481S), which prevents the irreversible binding of the drugs. In the present study we performed pre-clinical characterization of vecabrutinib, a next generation non-covalent BTK inhibitor, with ITK inhibitory properties similar to those of ibrutinib. Unlike ibrutinib and other covalent BTK inhibitors, vecabrutinib showed retention of the inhibitory effect on C481S BTK mutants in vitro, similar to that of wildtype BTK. In the murine Eµ-TCL1 adoptive transfer model, vecabrutinib reduced tumor burden and significantly improved survival. Vecabrutinib treatment led to a decrease in CD8+ effector and memory T-cell populations, while the naïve populations were increased. Of importance, vecabrutinib treatment significantly reduced frequency of regulatory CD4+ T-cells (Tregs) in vivo. Unlike ibrutinib, vecabrutinib treatment showed minimal adverse impact on activation and proliferation of isolated T-cells. Lastly, combination treatment of vecabrutinib with venetoclax was found to augment treatment efficacy, significantly improve survival and lead to favourable reprogramming of the microenvironment in the murine Eµ-TCL1 model. Thus, non-covalent BTK/ITK inhibitors such as vecabrutinib may be efficacious in C481S BTK mutant CLL, while preserving the T-cell immunomodulatory function of ibrutinib.

Sign in / Sign up

Export Citation Format

Share Document