scholarly journals Single cell multiomic analysis of T cell exhaustion in vitro

2019 ◽  
Author(s):  
Mirko Corselli ◽  
Suraj Saksena ◽  
Margaret Nakamoto ◽  
Woodrow E. Lomas ◽  
Ian Taylor ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
T Cell Activation ◽  
T Cell Exhaustion ◽  
Chronic Stimulation ◽  
Cell Exhaustion ◽  
Car T ◽  
The Impact

AbstractA key step in the clinical production of CAR-T cells is the expansion of engineered T cells. To generate enough cells for a therapeutic product, cells must be chronically stimulated, which raises the risk of inducing T-cell exhaustion and reducing therapeutic efficacy. As protocols for T-cell expansion are being developed to optimize CAR T cell yield, function and persistence, fundamental questions about the impact of in vitro manipulation on T-cell identity are important to answer. Namely: 1) what types of cells are generated during chronic stimulation? 2) how many unique cell states can be defined during chronic stimulation? We sought to answer these fundamental questions by performing single-cell multiomic analysis to simultaneously measure expression of 39 proteins and 399 genes in human T cells expanded in vitro. This approach allowed us to study – with unprecedented depth - how T cells change over the course of chronic stimulation. Comprehensive immunophenotypic and transcriptomic analysis at day 0 enabled a refined characterization of T-cell maturational states (from naïve to TEMRA cells) and the identification of a donor-specific subset of terminally differentiated T-cells that would have been otherwise overlooked using canonical cell classification schema. As expected, T-cell activation induced downregulation of naïve-associated markers and upregulation of effector molecules, proliferation regulators, co-inhibitory and co-stimulatory receptors. Our deep kinetic analysis further revealed clusters of proteins and genes identifying unique states of activation defined by markers temporarily expressed upon 3 days of stimulation (PD-1, CD69, LTA), markers constitutively expressed throughout chronic activation (CD25, GITR, LGALS1), and markers uniquely up-regulated upon 14 days of stimulation (CD39, ENTPD1, TNFDF10). Notably, different ratios of cells expressing activation or exhaustion markers were measured at each time point. These data indicate high heterogeneity and plasticity of chronically stimulated T cells in response to different kinetics of activation. In this study, we demonstrate the power of a single-cell multiomic approach to comprehensively characterize T cells and to precisely monitor changes in differentiation, activation and exhaustion signatures in response to different activation protocols.

100 Drug-regulatable engineered T cells eliminate CD33+ and CD33ΔE2+ AML

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A111-A111
Author(s):  
Jacob Appelbaum ◽  
Wai-Hang Leung ◽  
Unja Martin ◽  
Kaori Oda ◽  
Giacomo Tampella ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Splice Variants ◽  
Antigen Binding ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Car T

BackgroundBioengineered T cell treatments for acute myeloid leukemia (AML) are challenged by near universal expression of leukemia antigens on normal hematopoietic stem/progenitor cells:1 2 ‘on target/off tumor‘ activity may cause myelosuppression while sustained antigen exposure can lead to T cell exhaustion.3 In addition, splicing variants may allow antigen escape. We hypothesize that by using a novel CD33-C2-specific single domain VHH antibody as the antigen targeting domain in dimerizing agent-regulated immunoreceptor complex T cells (DARIC T cells), we will enable pharmacologically-controllable targeting of CD33, allowing eradication of leukemia expressing either of the major splice variants of CD33: i.e., full-length CD33 or CD33ΔE2.MethodsWe engineered DARIC-expressing lentiviral vectors containing encoding separated CD33-C2-specific antigen binding and 41BB-CD3zeta signaling chains that heterodimerize following addition of rapamycin via embedded FKBP12 and FRB* domains.4 Peripheral blood mononuclear cells were stimulated with IL-2, anti-CD3, and anti-CD28 antibodies 24h prior to transduction with DARIC33 lentiviral vector. Surface expression of antigen binding or signaling chains was assessed using biotinylated CD33, or antibodies to VHH-domains or FRB* respectively. Rapamycin-dependent in vitro activity was measured by IFNg release. To evaluate in vivo activity, NSG mice injected with 1 × 105 MOLM-14/luc cells were treated 5-7 days later with 1 × 107 DARIC33 T cells in the presence or absence of rapamycin and tumor progression followed by luciferase activity.ResultsDARIC33+ T cells bound biotinylated-CD33, anti-VHH and anti-FRB* antibodies. Rapamycin addition increased expression of both signaling and antigen-recognition chains, suggesting augmented receptor stability in the presence of dimerizing drug. In the presence of rapamycin, coculture of DARIC33 T cells with cell lines expressing either full length or CD33ΔE25 showed equivalent rapamycin-dependent activation, demonstrating DARIC33 responds to both splice variants. Titration experiments showed rapamycin-dependent activation with EC50 = 25pM. Negligible IFNg release was observed in the absence of drug. DARIC33 T cells significantly extended survival of AML-bearing mice, but only when treated with rapamycin. The DARIC33 T cells were activated in vivo by sub-immunosuppressive rapamycin dosing, as weekly or 0.1 mg/kg QOD dosing led to similar levels of tumor suppression.ConclusionsDARIC33 T cells appear to be potent antileukemic agents: they are activated by AML cell lines in vitro as demonstrated by cytokine release and cytotoxicity, and significantly extend survival in an aggressive xenograft model. Temporal control provided by the DARIC architecture promises to enhance safety and potentially efficacy of CAR T therapy for AML, for example by enabling hematopoietic recovery or providing T cell rest.ReferencesPerna F, Berman SH, Soni RK, Mansilla-Soto J, Eyquem J, Hamieh M, et al. Integrating proteomics and transcriptomics for systematic combinatorial chimeric antigen receptor therapy of AML. Cancer Cell 2017 Oct 9;32(4):506–519.e5.Haubner S, Perna F, Köhnke T, Schmidt C, Berman S, Augsberger C, et al. Coexpression profile of leukemic stem cell markers for combinatorial targeted therapy in AML. Leukemia. 2019 Jan;33(1):64.Lamarche C, Novakovsky GE, Qi CN, Weber EW, Mackall CL, Levings MK. Repeated stimulation or tonic-signaling chimeric antigen receptors drive regulatory T cell exhaustion. bioRxiv. 2020 Jun 28;2020.06.27.175158.Leung W-H, Gay J, Martin U, Garrett TE, Horton HM, Certo MT, et al. Sensitive and adaptable pharmacological control of CAR T cells through extracellular receptor dimerization. JCI Insight [Internet]. 2019 Jun 6 [cited 2019 Jun 11];4(11). Available from: https://insight.jci.org/articles/view/124430Pérez-Oliva AB, Martínez-Esparza M, Vicente-Fernández JJ, Corral-San Miguel R, García-Peñarrubia P, Hernández-Caselles T. Epitope mapping, expression and post-translational modifications of two isoforms of CD33 (CD33M and CD33m) on lymphoid and myeloid human cells. Glycobiology 2011;21(6):757–770.

scholarly journals Mutation of the CD28 Costimulatory Domain Confers Decreased CAR T Cell Exhaustion

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 966-966 ◽  
Author(s):  
Justin C. Boucher ◽  
Gongbo Li ◽  
Bishwas Shrestha ◽  
Maria Cabral ◽  
Dylan Morrissey ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract The therapeutic promise of chimeric antigen receptor (CAR) T cells was realized when complete remission rates of 90% were reported after treating B cell acute lymphoblastic leukemia (B-ALL) with CD19-targeted CAR T cells. However, a major obstacle with continued clinical development of CAR T cells is the limited understanding of CAR T cell biology and its mechanisms of immunity. We and others have shown that CARs with a CD28 co-stimulatory domain drive high levels of T cell activation causing acute toxicities, but also lead to T cell exhaustion and shortened persistence. The CD28 domain includes 3 intracellular subdomains (YMNM, PRRP, and PYAP) that regulate signaling pathways post TCR-stimulation, but it is unknown how they modulate activation and/or exhaustion of CAR T cells. A detailed understanding of the mechanism of CD28-dependent exhaustion in CAR T cells will allow the design of a CAR less prone to exhaustion and reduce relapse rates. We hypothesized that by incorporating null mutations of the CD28 subdomains (YMNM, PRRP, or PYAP) we could optimize CAR T cell signaling and reduce exhaustion. In vitro, we found mutated CAR T cells with only a functional PYAP (mut06) subdomain secrete significantly less IFNγ (Fig1A), IL6, and TNFα after 24hr stimulation compared to non-mutated CD28 CAR T cells, but greater than the 1st generation m19z CAR. Also, cytoxicity was enhanced with the PYAP only CAR T cells compared to non-mutated CARs (Fig1B). When we examined the PYAP (mut06) only mutant in an immune competent mouse model we found similar B cell aplasia and CAR T cell persistence compared to non-mutated CD28 CAR T cells. Additionally, PYAP only CAR T cells injected into mice had decreased (82% to 62%) expression of PD1 in the BM. Using a pre-clinical immunocompetent mouse tumor model we found the PYAP only CAR T cell treated mice had a significant survival advantage compared to non-mutated CD28 CAR T cells, with 100% survival of mice given PAYP only CAR T cells compared to 50% survival of mice given non-mutated CAR T cells (Fig1C). We next sought to determine what role CAR T cell exhaustion was playing using a Rag knockout mouse system. CAR T cells were given to Rag-/- mice and 1 week later mice were challenged with tumor. Studies in Rag-/- mice also showed PYAP only CAR T cells were increased 35% in the BM and 92% in the spleen compared to non-mutated CD28 CAR T cells. We also found PYAP only CAR T cells had significantly less expression of PD1 compared to non-mutated CAR T cells (Fig1D). We then co-cultured CAR T cells with target cells expressing CD19 and PDL1 and found PYAP only CAR T cells had increased IFNγ (42%), TNFα (62%) and IL2 (73%) secretion compared to exhausted non-mutated CD28 CAR T cells. This shows that PYAP only CAR T cells are more resistant to exhaustion. To find a mechanistic explanation for this observation we examined CAR T cell signaling. Using Nur77, pAkt, and pmTOR to measure CAR signaling we found PYAP only CAR T cells had significantly reduced levels of Nur77 while still having higher expression then first generation CAR T cells. We then examined what affect the PYAP only CAR had on transcription factors. We found similar AP1 and NF-kB expression between PYAP only and non-mutated CD28 CAR T cells but a significant reduction of NFAT in the PYAP only mutants compared to non-mutated CD28 CAR T cells. This suggests reduced NFAT expression contributes to the PYAP only CAR's resistance to exhaustion. Finally, we made human CAR constructs of the PYAP only mutant. We found PYAP only human CAR T cells had increased cytoxicity and decreased exhaustion in vitro compared to non-mutated human CD28 CAR T cells. NFAT levels in human PYAP only CAR T cells were significantly reduced compared to non-mutated CAR T cells supporting our findings in mice. Our results demonstrate that CAR T cells with only a PYAP CD28 subdomain have better cytoxicity and decreased exhaustion compared to non-mutated CD28 CAR T cells. Our results suggest this is the result of decreased CAR and NFAT signaling. Additionally, we were able to validate these findings using human CAR constructs. This work allows for development of an enhanced 2nd and 3rd generation CAR T cell therapies for B cell malignancies by optimizing CAR T cell activation and persistence which may reduce relapse rates and severe toxicities. Figure 1 Figure 1. Disclosures Davila: Celyad: Consultancy, Membership on an entity's Board of Directors or advisory committees.

142 Contextual reprogramming of CAR T cells for the treatment of HER2-expressing cancers

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A156-A156
Author(s):  
Zhifen Yang ◽  
Lingyu Li ◽  
Ahu Turkoz ◽  
Pohan Chen ◽  
Hana Choi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Proliferation In Vitro

BackgroundCombining checkpoint inhibition (CPI) to adoptive cell therapy (ACT) is a promising strategy to prevent chimeric antigen receptor (CAR)-engineered T cell exhaustion and improve outcomes. However, cumulative toxicities and costs limit this approach. Here, we apply a conditional, antigen-dependent non-editing CRISPR interference-(CRISPRi) modulation circuit that we originally described in yeast and eukaryotes1–3 (RB-340-1) to promote CAR T resilience to checkpoint suppression extending in vivo persistence and effectiveness.MethodsRB-340-1 is an CAR T cell product engineered via synthetic biology approaches to express a combination of molecules to prevent CAR T cell exhaustion and improve solid tumor treatment outcomes. The components include two constructs. The first construct encodes an anti-HER2 (4D5) CAR single chain variable fragment (scFv), with CD28 and CD3ζ co-stimulatory domains linked to a tobacco etch virus (TEV) protease and a programmed cell death protein 1 (PD1) promoter region-targeting single guide RNA (PD1sg). The second construct encodes a protein, linker for activation of T cells (LAT), complexed to nuclease-deactivated/dead Cas9 (dCas9)-Kruppel-associated box (Krab) via a TEV-cleavable linker. Activation of CAR brings CAR-TEV in close proximity to the LAT-dCas9-Krab complex releasing the enzyme for nuclear localization to the PD1 regulatory region to conditionally and reversibly suppress its expression. RB-340-1 was compared in vitro and in vivo against conventional and control (cRB-340-1, lacking PD1sg) HER2 CAR T cells in combination with CPI with Atezolizumab (5 mg/Kg administered intravenously twice a week).ResultsRB-340-1 consistently induced higher production of homeostatic cytokines such as IL-2 resulting in significantly enhanced proliferation in vitro (figure 1a). Our in vivo data showed significantly enhanced suppression of growth of HER2+ FADU oropharyngeal cancer xenografts upon intra-tumoral (figure 1b) and systemic administration (figure 1c) and prolonged persistence of CAR T cells in vivo.Abstract 142 Figure 1Rb-340-1 performance in vitro and in vivoRB-340-1 (orange) decreased PD-1 expression resulting in enhanced cytokine production and proliferation in vitro (figure 1a) and superior tumor suppression in vivo after intra-tumoral (figure 1b) or intravenous (figure 1c) administration compared to conventional CAR T cells (blue) or cRB-340-1 (green). Conventional CAR T cells or cRB-340-1 CAR T combination treatment with PDL1 blockade (Atezolizumab) is shown as dashed line. Colonization of tumors by human CD45+ cells is shown at the bottom of figure 1b & 1cConclusionsIntrinsic conditional regulation of checkpoint expression in CAR T cells provides a simplified approach to combination therapies that limits systemic toxicities and reduces costs. Since the expression of multiple genes can be simultaneously controlled by CRISPRi, broader applications can be envisioned in the future.Ethics ApprovalNot ApplicableConsentNot applicableReferencesGilbert LA, Horlbeck MA, Adamson B, Villalta JE, Chen Y, Whitehead EH, et al. Genome-Scale CRISPR-mediated control of gene repression and activation. Cell 2014;159(3):647-61.Gilbert LA, Larson MH, Morsut L, Liu Z, Brar GA, Torres SE, et al. CRISPR-mediated modular RNA-guided regulation of transcription in eukaryotes. Cell 2013;154(2):442–51.Qi LS, Larson MH, Gilbert LA, Doudna JA, Weissman JS, Arkin AP, et al. Repurposing CRISPR as an RNA-guided platform for sequence-specific control of gene expression. Cell 2013;152(5):1173–83.

107 Effects of IL-2 and IL-15 on the proliferative and antitumor capacities of allogeneic CD20 CAR-engineered γδ T cells in a 3D B cell lymphoma spheroid assay

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A119-A119
Author(s):  
Lu Bai ◽  
Kevin Nishimoto ◽  
Mustafa Turkoz ◽  
Marissa Herrman ◽  
Jason Romero ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytokine Production ◽  
Γδ T Cells ◽  
Γδ T Cell ◽  
Car T

BackgroundAutologous chimeric antigen receptor (CAR) T cells have been shown to be efficacious for the treatment of B cell malignancies; however, widespread adoption and application of CAR T cell products still face a number of challenges. To overcome these challenges, Adicet Bio is developing an allogeneic γδ T cell-based CAR T cell platform, which capitalizes on the intrinsic abilities of Vδ1 γδ T cells to recognize and kill transformed cells in an MHC-unrestricted manner, to migrate to epithelial tissues, and to function in hypoxic conditions. To gain a better understanding of the requirements for optimal intratumoral CAR Vδ1 γδ T cell activation, proliferation, and differentiation, we developed a three-dimensional (3D) tumor spheroid assay, in which tumor cells acquire the structural organization of a solid tumor and establish a microenvironment that has oxygen and nutrient gradients. Moreover, through the addition of cytokines and/or tumor stromal cell types, the spheroid microenvironment can be modified to reflect hot or cold tumors. Here, we report on the use of a 3D CD20+ Raji lymphoma spheroid assay to evaluate the effects of IL-2 and IL-15, positive regulators of T cell homeostasis and differentiation, on the proliferative and antitumor capacities of CD20 CAR Vδ1 γδ T cells.MethodsMolecular, phenotypic, and functional profiling were performed to characterize the in vitro dynamics of the intraspheroid CD20 CAR Vδ1 γδ T cell response to target antigen in the presence of IL-2, IL-15, or no added cytokine.ResultsWhen compared to no added cytokine, the addition of IL-2 or IL-15 enhanced CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and cytokine production in a dose-dependent manner but were only able to alter the kinetics of Raji cell killing at low effector to target ratios. Notably, differential gene expression analysis using NanoString nCounter® Technology confirmed the positive effects of IL-2 or IL-15 on CAR-activated Vδ1 γδ T cells as evidenced by the upregulation of genes involved in activation, cell cycle, mitochondrial biogenesis, cytotoxicity, and cytokine production.ConclusionsTogether, these results not only show that the addition of IL-2 or IL-15 can potentiate CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation into antitumor effectors but also highlight the utility of the 3D spheroid assay as a high throughput in vitro method for assessing and predicting CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation in hot and cold tumors.

scholarly journals Tim-3 co-stimulation promotes short-lived effector T cells, restricts memory precursors, and is dispensable for T cell exhaustion

2018 ◽  
Vol 115 (10) ◽  
pp. 2455-2460 ◽  
Author(s):  
Lyndsay Avery ◽  
Jessica Filderman ◽  
Andrea L. Szymczak-Workman ◽  
Lawrence P. Kane
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Chronic Infection ◽  
Cell Activation ◽  
Effector T Cells ◽  
Mtor Signaling ◽  
T Cell Exhaustion ◽  
Inhibitory Protein ◽  
Cell Exhaustion

Tim-3 is highly expressed on a subset of T cells during T cell exhaustion in settings of chronic viral infection and tumors. Using lymphocytic choriomeningitis virus (LCMV) Clone 13, a model for chronic infection, we found that Tim-3 was neither necessary nor sufficient for the development of T cell exhaustion. Nonetheless, expression of Tim-3 was sufficient to drive resistance to PD-L1 blockade therapy during chronic infection. Strikingly, expression of Tim-3 promoted the development of short-lived effector T cells, at the expense of memory precursor development, after acute LCMV infection. These effects were accompanied by increased Akt/mTOR signaling in T cells expressing endogenous or ectopic Tim-3. Conversely, Akt/mTOR signaling was reduced in effector T cells from Tim-3–deficient mice. Thus, Tim-3 is essential for optimal effector T cell responses, and may also contribute to exhaustion by restricting the development of long-lived memory T cells. Taken together, our results suggest that Tim-3 is actually more similar to costimulatory receptors that are up-regulated after T cell activation than to a dominant inhibitory protein like PD-1. These findings have significant implications for the development of anti–Tim-3 antibodies as therapeutic agents.

scholarly journals Chimeric Antigen Receptor T Cell Exhaustion during Treatment for Hematological Malignancies

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chunyi Shen ◽  
Zhen Zhang ◽  
Yi Zhang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Hematological Malignancies ◽  
Antigen Receptor ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Immunotherapy, especially based on chimeric antigen receptor (CAR) T cells, has achieved prominent success in the treatment of hematological malignancies. However, approximately 30-50% of patients will have disease relapse following remission after receiving CD19-targeting CAR-T cells, with failure of maintaining a long-term effect. Mechanisms underlying CAR-T therapy inefficiency consist of loss or modulation of target antigen and CAR-T cell poor persistence which mostly results from T cell exhaustion. The unique features and restoration strategies of exhausted T cells (Tex) have been well described in solid tumors. However, the overview associated with CAR-T cell exhaustion is relatively rare in hematological malignancies. In this review, we summarize the characteristics, cellular, and molecular mechanisms of Tex cells as well as approaches to reverse CAR-T cell exhaustion in hematological malignancies, providing novel strategies for immunotherapies.

scholarly journals Allergen-Induced C5a/C5aR1 Axis Activation in Pulmonary CD11b+ cDCs Promotes Pulmonary Tolerance through Downregulation of CD40

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 300 ◽  
Author(s):  
Konstantina Antoniou ◽  
Fanny Ender ◽  
Tillman Vollbrandt ◽  
Yves Laumonnier ◽  
Franziska Rathmann ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
T Cell Proliferation ◽  
C5a Receptor ◽  
The Impact

Activation of the C5/C5a/C5a receptor 1 (C5aR1) axis during allergen sensitization protects from maladaptive T cell activation. To explore the underlying regulatory mechanisms, we analyzed the impact of C5aR1 activation on pulmonary CD11b+ conventional dendritic cells (cDCs) in the context of house-dust-mite (HDM) exposure. BALB/c mice were intratracheally immunized with an HDM/ovalbumin (OVA) mixture. After 24 h, we detected two CD11b+ cDC populations that could be distinguished on the basis of C5aR1 expression. C5aR1− but not C5aR1+ cDCs strongly induced T cell proliferation of OVA-reactive transgenic CD4+ T cells after re-exposure to antigen in vitro. C5aR1− cDCs expressed higher levels of MHC-II and CD40 than their C5aR1+ counterparts, which correlated directly with a higher frequency of interactions with cognate CD4+ T cells. Priming of OVA-specific T cells by C5aR1+ cDCs could be markedly increased by in vitro blockade of C5aR1 and this was associated with increased CD40 expression. Simultaneous blockade of C5aR1 and CD40L on C5aR1+ cDCs decreased T cell proliferation. Finally, pulsing with OVA-induced C5 production and its cleavage into C5a by both populations of CD11b+ cDCs. Thus, we propose a model in which allergen-induced autocrine C5a generation and subsequent C5aR1 activation in pulmonary CD11b+ cDCs promotes tolerance towards aeroallergens through downregulation of CD40.

scholarly journals Repeated stimulation or tonic-signaling chimeric antigen receptors drive regulatory T cell exhaustion

2020 ◽  
Author(s):  
Caroline Lamarche ◽  
German E. Novakovsky ◽  
Christopher N. Qi ◽  
Evan W. Weber ◽  
Crystal L. Mackall ◽  
...  
Keyword(s):  
T Cell ◽  
Regulatory T Cell ◽  
T Cell Exhaustion ◽  
Antigen Receptors ◽  
Chronic Stimulation ◽  
T Cell Therapy ◽  
Cell Exhaustion ◽  
Graft Versus Host

AbstractRegulatory T cell (Treg) therapy is a promising approach to improve outcomes in transplantation and autoimmunity. In conventional T cell therapy, chronic stimulation can result in poor in vivo function, a phenomenon termed exhaustion. Whether or not Tregs are also susceptible to exhaustion, and if so, if this would limit their therapeutic effect, was unknown. We studied how two methods which induce conventional T cell exhaustion – repetitive stimulation or expression of a tonic-signaling chimeric antigen receptor (CAR) – affect human Tregs. With each repetitive polyclonal stimulation Tregs progressively acquired an exhausted phenotype, and became less suppressive in vitro. Tregs expressing a tonic-signaling CAR rapidly acquired an exhausted phenotype and had major changes in their transcriptome and metabolism. Although tonic-signaling CAR-Tregs remained stable and suppressive in vitro, they lost in vivo function, as tested in a model of xenogeneic graft-versus-host disease. The finding that human Tregs are susceptible to exhaustion has important implications for the design of Treg adoptive immunotherapy strategies.

scholarly journals PLAC8 Correlates with Prognosis, Immune Infiltration, and T Cell Exhaustion in Breast Cancer

2021 ◽  
Author(s):  
Pan Liao ◽  
Ying Wang ◽  
Lixia Sun ◽  
Hongpeng Yue
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Prognostic Significance ◽  
Her2 Status ◽  
Gene Marker ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Immune Infiltration

Abstract Background: Lysosomal protein placenta-specific 8 (PLAC8) with abundant cysteine, also referred to as onzin, participates in numerous cancers, and its effect is greatly determined by the cellular and tumor microenvironment (TME). Ourstudy focused on investigating the prognostic significance of PLAC8 and examined the association between PLAC8, immune infiltration, and T cells function in multiple malignancies comprehensively, particularly in breast cancer (BRCA).Methods: PLAC8 expression in various malignancies was analyzed using TIMER. PrognoScan, Kaplan-Meier Plotter, and GEPIA2 were utilized to explore the significance of PLAC8 in prognostic prediction. Moreover, PLAC8 functions were systematically analyzed through cancerSEA. Additionally, TISIDB, TIMER, and GEPIA2 were also employed for analyzing the associations among PLAC8, immune infiltration, related gene marker sets, and clinical stages. Finally, PLAC8 and its co-expressed genes biological process and KEGG were analyzed. Results: PLAC8 expression decreased in most malignancies and was related to poor prognosis in BRCA. PLAC8 significantly affected the survival of BRCA with ER status – array, PR status – IHC, HER2 status – array, Intrinsic subtype, Grade, and Pietenpol subtype. Increased PLAC8 expression positively correlated with the increased immune infiltration levels within immune cells and many functional T cells (such as exhausted T cells). In BRCA cells, PLAC8 functional phenotypesshowed a negative correlation with invasion, metastasis, apoptosis, DNA damage, and DNA repair. Besides, PD-1, TIM-3, TIGIT, LAG3, and GZMB, critical genes of exhausted T cells, interacted with PLAC8. Further analysis indicated that PLAC8 was related to T cell activation, proliferation and adhesion of leukocytes,adaptive immune response, cell adhesion molecules (CAMs), cytotoxicity-mediated by natural killer cells, and the NF-kappa B signal transduction pathway.Conclusion:PLAC8 is a prognostic indicator in pan-cancers, especially BRCA. Elevated PLAC8 level could significantly enhance immune infiltration in CD4+ T cells, CD8+ T cells, and functional T cells. Additionally, PLAC8 was tightly associatedwith T cell exhaustion which possibly enhances the latterwithin BRCA. PLAC8 expression determination might help in prognosis, and modulation of PLAC8level within exhausted T cells, a novel approach for optimizing the therapeutic effect of immunotherapy on BRCA cases.

Pseudo-Exhaustion Of CD8+ T Cells in AML

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2615-2615 ◽  
Author(s):  
Felix S. Lichtenegger ◽  
Frauke M. Schnorfeil ◽  
Katharina Emmerig ◽  
Julia S. Neitz ◽  
Barbara Beck ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Peptide Pool ◽  
Primary Diagnosis ◽  
Refractory Disease ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Inhibitory Molecules

Abstract The prognosis of acute myeloid leukemia (AML), particularly when associated with adverse chromosomal or molecular aberrations, is poor due to a high relapse rate after induction chemotherapy. Postremission therapy for elimination of minimal residual disease remains a major challenge. Immunotherapeutic strategies such as dendritic cell (DC) vaccination aim at the stimulation of AML-specific immunity, especially of CD8+ T cells. However, the functionality of these cells in AML patients is not well described. Recently, T cell exhaustion has been suggested to contribute to immune evasion in various solid and hematological malignancies. Primarily demonstrated in chronic viral infections, exhausted T cells are characterized by an increased expression of several inhibitory molecules, reduced proliferation and an impaired capability of cytokine secretion and cytotoxicity. In order to characterize T cell exhaustion in AML at primary diagnosis and during refractory disease, we assessed the phenotype and effector function of CD8+ T cells by flow cytometry. Surface expression of the inhibitory molecules CD244 (2B4), CD160, PD-1, TIM-3 and LAG-3 was determined. T cell proliferation and production of the cytokines IFN-γ, TNF-α and IL-2 were measured in response to different stimuli. Results were compared to healthy controls (HCs), while untreated HIV-infected patients served as positive controls for an exhausted state of CD8+ T cells. To specify the effect of DCs on the state of T cell exhaustion in AML, we cocultured in vitro generated DCs with autologous T cells from primary diagnosis for four days. Compared to HCs, we detected similarly increased frequencies of CD244- and TIM-3-positive CD8+ T cells in AML and HIV patients (CD244: HCs 37±17%, AML primary diagnosis/refractory disease 72±21%/67±9%, HIV 70±7%; TIM-3: HCs 1.1±1.5%, AML primary diagnosis/refractory disease 2.9±2.2%/4.7±4.4%, HIV 2.9±2.4%; mean±SD). In refractory AML, we additionally observed an increased frequency of CD8+ T cells positive for CD160 and PD-1 (CD160: HCs 19±9%, AML refractory disease 32±8%; PD-1: HCs 21±8%, AML refractory disease 50±25%). In our functional analyses, however, T cells from AML patients and HCs were equally able to produce IFN-γ, TNF-α and IL-2 upon in vitro stimulation with a CEFT peptide pool, PMA/Ionomycin or anti-CD3/CD28. Using the CEFT peptide pool for stimulation, we even measured an increase in proliferation of T cells from AML patients compared to T cells from HCs and HIV-infected patients. The in vitro stimulation of AML cells with DCs generated from autologous monocytes resulted in a further upregulation of the molecules PD-1 and TIM-3. In summary, we found an increased overall expression of inhibitory surface molecules associated with T cell exhaustion on CD8+ T cells of AML patients at primary diagnosis and with refractory disease, which was further enhanced by in vitro stimulation with DCs. In contrast, no impairment of functionality was detected, as determined by proliferation and cytokine secretion assays. We therefore hypothesize that bulk CD8+ T cells in AML are in a status of activation, not exhaustion. Disclosures: No relevant conflicts of interest to declare.

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