scholarly journals Treatment-Free Intervals Mitigate T-Cell Exhaustion Induced By Continuous CD19xCD3-BiTE® Construct Stimulation in Vitro

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 44-45
Author(s):  
Nora Zieger ◽  
Alyssa Nicholls ◽  
Jan Wulf ◽  
Gerulf Hänel ◽  
Maryam Kazerani Pasikhani ◽  
...  

The bispecific T-cell engager (BiTE®) blinatumomab is approved for treatment of relapsed/refractory B-cell precursor acute lymphoblastic leukemia and applied as continuous infusion over 28 days. The overall response rate to blinatumomab reported in clinical trials was 43 % and correlated to T-cell expansion (Zugmaier et al. 2015). In chronic viral infections, continuous antigen stimulation induces T-cell exhaustion, defined by phenotypic changes and functional impairment (Wherry 2011). Thus, we hypothesized that continuous BiTE® construct stimulation leads to T-cell exhaustion and that a treatment-free interval (TFI) reverses progressive T-cell dysfunction. To simulate continuous application of a BiTE® construct in vitro, T-cell long-term co-cultures were set up. Healthy donor T cells were stimulated in the presence of CD19+ OCI-Ly1 cells for 28 days with AMG 562, a half-life extended CD19 and CD3 specific BiTE® construct. T cells were harvested from the co-culture every 3-4 days between day 7 and 28 and assessed for markers of T-cell exhaustion: (1) AMG 562-mediated cytotoxicity of T cells was evaluated as specific lysis of CD19+ Ba/F3 target cells after 3 days, (2) T-cell expansion during the cytotoxicity assay was calculated as fold change (FC) of CD2+ counts, (3) Cytokine secretion of AMG 562-stimulated T cells was evaluated in co-culture supernatants by cytometric bead array (CBA) or after PMA/Ionomycine stimulation via intracellular cytokine staining (ICCS), (4) T-cell metabolic fitness was determined by Mito- and Glycolytic Stress Test using a Seahorse Analyzer, and (5) expression of the exhaustion-related transcription factor TOX was assessed by multiparameter flow cytometry. In order to assess the effect of a TFI on T-cell function, we cultured T cells and CD19+ OCI-Ly1 cells in the absence of AMG 562 from day 7-14 and 21-28 and compared their activity to T cells stimulated continuously with AMG 562. On day 7 of continuous (CONT) AMG 562 stimulation, we observed high cytotoxic and proliferative potential (% specific lysis=93±0.2, FC=2.9±0.2) as well as high IFN-g and TNF-a secretion analyzed by ICCS (% CD8+IFN-g+TNF-a+=23±6.7). However, cytotoxicity and proliferation decreased gradually until day 28 (% specific lysis=28±8.9; FC=0.6±0.1). CBA analysis confirmed decreasing secretion of IFN-g (day 3: 61113±12482, day 24: 3085±1351 pg/ml) and TNF-a (day 3: 1160±567, day 24: 43±7.6 pg/ml) as well as decreased IL-2 and granzyme B levels in culture supernatants. We furthermore observed highest mitochondrial fitness and basal glycolysis in T cells on day 7 of stimulation (basal OCR=2.2±0.6, maximal OCR=3.7±1.0, SRC=1.5±1.1 pmol/min/1000 cells, basal ECAR=2.0±0.4 mpH/min/1000 cells) which decreased until day 28 (basal OCR=0.4±0.2, maximal OCR=1.5±0.5, SRC=1.0±0.2 pmol/min/1000 cells, basal ECAR=0.5±0.2 mpH/min/1000 cells). In concordance, TOX increased during continuous stimulation (MFI ratio CD8+ day 7=6±0.8 to 12±0.8 on day 28). Strikingly, implementation of a TFI of 7 days led to superior cytotoxicity in T cells compared to continuously stimulated T cells (% specific lysis on day 14 CONT=34±4.2, TFI=99±2.2) and granzyme B production (CD8+; MFI ratio on day 14 CONT=124±11, TFI=303±34). Furthermore, increased proliferation during the cytotoxicity assay was observed in previously rested T cells (FC CONT=0.2±0.0, TFI=1.6±0.6). Although T cell function also decreased over time in TFI T cells, they maintained a strikingly higher cytotoxic potential (CONT=6±4.4, TFI=52±9.9) as well as higher granzyme B production (CONT=25±2, TFI=170±11) on day 28 compared to continuously stimulated T cells. In addition, TFI T cells showed increased IFN-g and TNF-a secretion after PMA/Ionomycine stimulation on day 28 (% CD8+IFN-g+TNF-a+ CONT=21±3.8, TFI=38±11.6). Our in vitro results demonstrate that continuous AMG 562 exposure negatively impacts T-cell function. Comprehensive analysis of T-cell activity in an array of functional assays suggests that continuous BiTE® construct exposure leads to T-cell exhaustion which can be mitigated through TFI. Currently, T cells from patients receiving blinatumomab are being analyzed to confirm the clinical relevance of our findings. Furthermore, RNA-Seq of continuously vs. intermittently AMG 562-exposed T cells will help us to understand underlying transcriptional mechanisms of BiTE® construct induced T-cell exhaustion. Disclosures Zieger: AMGEN Research Munich: Research Funding. Buecklein:Pfizer: Consultancy; Novartis: Research Funding; Celgene: Research Funding; Amgen: Consultancy; Gilead: Consultancy, Research Funding. Brauchle:AMGEN Inc.: Research Funding. Marcinek:AMGEN Research Munich: Research Funding. Kischel:AMGEN: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties. Subklewe:Gilead Sciences: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Morphosys: Research Funding; Seattle Genetics: Research Funding; AMGEN: Consultancy, Honoraria, Research Funding; Janssen: Consultancy; Roche AG: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Celgene: Consultancy, Honoraria.

Author(s):  
Fei Li ◽  
Huiling Liu ◽  
Dan Zhang ◽  
Bingdong Zhu

Recent studies have shown that T cell metabolism has become a key regulator of T cell function and even can determine T cell function at last. Naïve T cells use fatty acid oxidation (FAO) to meet their energetic demands. Effector T cells mainly rely on aerobic glycolysis to supply energy and synthesize intermediate products. Similar to naïve T cells, memory T cells primarily utilize FAO for energy. Exhausted T cells, which can be induced by continuous activation of T cells upon persistently chronic infections such as tuberculosis, mainly rely on glycolysis for energy. The prevention and treatment of T cell exhaustion is facing great challenges. Interfering T cell metabolism may achieve the goal of prevention and treatment of T cell exhaustion. In this review, we compiled the researches related to exhausted T cell metabolism and put forward the metabolic intervention strategies to reverse T cell exhaustion at different stages to achieve the purpose of preventing and treating T cell exhaustion.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 916-916
Author(s):  
Michael Quigley ◽  
Florencia Pereyra ◽  
Bjorn Nilsson ◽  
Quentin Eichbaum ◽  
Boris Julg ◽  
...  

Abstract Abstract 916 T cells responding to chronic infections such as HIV lose the ability to secrete cytokines or to proliferate, functions critical for control of viral replication, in a process termed exhaustion. However the molecular mechanisms of T cell exhaustion are not understood, and few therapeutic targets to reinvigorate exhausted T cells have been identified. We therefore conducted a comprehensive genomic analysis of HIV-specific CD8+ T cells to identify the mechanisms underlying defective function in T cell exhaustion. We used Affymetrix microarrays to study gene expression profiles from sorted Gag-specific tetramer+ CD8+ T cells in two cohorts of HIV-infected individuals that differed in their extent of T cell exhaustion: a) Progressors (n=24), who show chronic elevation of viral load and have defects in HIV-specific T cell cytokine secretion, proliferation and survival; and b) Controllers (n=18), who show spontaneous control of viral replication and have relatively good HIV-specific T cell function. Profiles of Gag-specific CD8+ T cells (median 21,500 cells/sample) from progressors showed marked alterations in gene expression compared with those from controllers (n=518 genes upregulated in progressors, moderated t-statistic >2.0). There was highly significant similarity at the whole-genome level between dysfunctional Gag-specific CD8+ T cells from progressors and exhausted CD8+ T cells in the mouse model of chronic LCMV infection (gene set enrichment analysis, P=4.8e−005), suggesting that T cell exhaustion is associated with an evolutionarily conserved program of gene expression. Next, we determined whether this exhausted signature was influenced by inhibitory signaling via the receptor PD-1, an inhibitory receptor known to be upregulated in expression on exhausted T cells. We developed an in vitro model of PD-1 signaling and identified a unique signature of genes upregulated by PD-1 ligation. The signature of PD-1 induced genes was highly significantly upregulated in profiles from Gag-specific CD8+ T cells in HIV progressors compared to controllers (P=5e−006), and in exhausted CD8+ T cells from the LCMV mouse model (P=2e−004). Thus the signature of T cell exhaustion in humans and mice is driven in part by the consequences of PD-1 signaling. Finally, we asked whether the genes upregulated by PD-1 in exhausted T cells directly inhibit T cell function. PD-1 ligation upregulated the transcription factor BATF in HIV-specific CD8+ T cells and in exhausted CD8+ T cells from the mouse model of LCMV infection. Enforced expression of BATF, an inhibitory member of the AP-1 family, in normal human T cells inhibited proliferation (P=0.02) and IL2 secretion (P=4.5e-05). Infection with LCMV in BATF transgenic mice resulted in marked acceleration of T cell exhaustion compared to wild-type animals, indicating that BATF represses T cell effector functions. Silencing of BATF using shRNA in primary human T cells showed that it was required for PD-1 mediated inhibition of T cell function. In summary, our results demonstrate that 1) PD-1 ligation induces a conserved transcriptional program in exhausted HIV-specific CD8+ T cells and in exhausted LCMV-specific CD8+ T cells in the mouse; 2) this transcriptional program includes the upregulation of genes such as BATF that directly inhibit T cell function. Our data suggest that BATF causes the functional defects seen in T cell exhaustion, and represents a new therapeutic target to rescue T cell function in HIV infection. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ariana N. Renrick ◽  
Menaka C. Thounaojam ◽  
Maria Teresa P. de Aquino ◽  
Evan Chaudhuri ◽  
Jui Pandhare ◽  
...  

Suppressive mechanisms operating within T cells are linked to immune dysfunction in the tumor microenvironment. We have previously reported using adoptive T cell immunotherapy models that tumor–bearing mice treated with a regimen of proteasome inhibitor, bortezomib - a dipeptidyl boronate, show increased antitumor lymphocyte effector function and survival. Here, we identify a mechanism for the improved antitumor CD8+ T cell function following bortezomib treatment. Intravenous administration of bortezomib at a low dose (1 mg/kg body weight) in wild-type or tumor-bearing mice altered the expression of a number of miRNAs in CD8+ T cells. Specifically, the effect of bortezomib was prominent on miR-155 - a key cellular miRNA involved in T cell function. Importantly, bortezomib–induced upregulation of miR-155 was associated with the downregulation of its targets, the suppressor of cytokine signaling 1 (SOCS1) and inositol polyphosphate-5-phosphatase (SHIP1). Genetic and biochemical analysis confirmed a functional link between miR-155 and these targets. Moreover, activated CD8+ T cells treated with bortezomib exhibited a significant reduction in programmed cell death-1 (PD-1) expressing SHIP1+ phenotype. These data underscore a mechanism of action by which bortezomib induces miR-155–dependent downregulation of SOCS1 and SHIP1 negative regulatory proteins, leading to a suppressed PD-1–mediated T cell exhaustion. Collectively, data provide novel molecular insights into bortezomib–mediated lymphocyte–stimulatory effects that could overcome immunosuppressive actions of tumor on antitumor T cell functions. The findings support the approach that bortezomib combined with other immunotherapies would lead to improved therapeutic outcomes by overcoming T cell exhaustion in the tumor microenvironment.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3032-3032
Author(s):  
Arantxa Romero-Toledo ◽  
Robin Sanderson ◽  
John G. Gribben

The complex crosstalk between malignant chronic lymphocytic leukemia (CLL) cells and the tumor microenvironment (TME) is not fully understood. CLL is associated with an inflammatory TME and T cells exhibit exhaustion and multiple functional defects, fully recapitulated in Eµ-TCL1 (TCL1) mice and induced in healthy mice by adoptive transfer (AT) of murine CLL cells, making it an ideal model to test novel immunotherapies for this disease. Myeloid-derived suppressor cells (MDSCs), a non-leukemic cell type within the TME, are immature myeloid cells with the ability to suppress T cell function and promote Treg expansion. In humans, CLL cells can induce conversion of monocytes to MDSCs provoking their accumulation in peripheral blood (PB). MDSCs include two major subsets granulocytic (Gr) and monocytic (M)-MDSC. In mice, Gr-MDSCs are defined as CD11b+Ly6G+Ly6Clo and M-MDSC as CD11b+Ly6G-Ly6Chi. Both murine and human MDSCs express BTK. We observed that in CLL-bearing mice, MDSCs cells are lost in PB as disease progresses. Treatment with both BTK inhibitors (BTKi), ibrutinib (Ibr) and acalabrutinib (Acala), result in shift of T cell function from Th2 towards Th1 polarity and increase MDSC populations in vivo. We aimed to determine whether combination treatment with BTKi and chimeric antigen receptor (CAR) T cells renders recovery of the MDSC population in CLL-bearing mice. To address this question we designed a two-part experiment, aiming to mimic the clinically relevant scenario of pre-treatment of CLL with BTKi to improve CAR T cell function. Part 1 of our experiment consisted of 4 groups (n=12) of 2.5 month old C57/Bl6 mice. Three groups had AT with 30x106 TCL1 splenocytes. A fourth group of WT mice remained CLL-free as a positive control and donors for WT T cells. When PB CLL load reached >10% (day 14) animals were randomized to either Ibr or Acala at 0.15 mg/l in 2% HPBC or no treatment for 21 days. All animals from part 1 were culled at day 35 post-AT and splenic cells were isolated, analyzed and used to manufacture CAR T cells. WT, CLL, Ibr and Acala treated T cells were activated and transduced with a CD19-CD28 CAR to treat mice in part 2. Here, 50 WT mice were given AT with 20x106 TCL1 splenocytes for CLL engraftment. All mice were injected with lymphodepleting cyclophosphamide (100mg/kg IP) one day prior to IV CAR injection. At day 21 post-AT, mice were treated with WT CAR, CLL CAR, IbrCAR, AcalaCAR or untransduced T cells. MDSC sub-populations were monitored weekly in PB and SP were analysed by flow cytometry. As malignant CD19+CD5+ cells expands in PB, the overall myeloid (CD19-CD11b+) cell population was not affected, but MDSCs significantly decreased (p<0.0001). Treatment with Acala, but not Ibr restores total MDSCs. However, MDSC impairment occurs in the Gr- but not M- MDSC population and both Acala and Ibr restores this population (Figure 1a). When we examined the spleen, treatment with both Ibr (p<0.001) and Acala (p<0.001) reduced CD5+CD19+ cells, whereas neither BTKi affected the overall myeloid (CD19-CD11b+) cell population. Gr-MDSCs were restored by both treatments whilst M-MDSCs were only restored after Ibr treatment (p<0.001 in each case). In part 2 of this experiment we observed that treatment with all CAR-T cell groups provokes the clearance of all CD19+CD5+ cells. The overall CD19-CD11b+ population stays the same across all mice groups 35 days after treatment in PB with any group of CAR and untransduced T cells. Overall MDSC population is maintained following all CAR T cells compared to CLL-bearing mice (p<0.0001) and it is the Gr- but not the M- MDSC population which is recovered in PB (Figure 1b). These parts of the experiments can of course be influenced by treatment with cyclophosphamide. We conclude that novel therapies for CLL treatment have an effect not only in CLL cells but also in non-malignant cell components of the TME. In this animal model of CLL, the rapid expansion of CLL cells in PB and secondary lymphoid organs provokes loss of MDSC, particularly the Gr-MDSC subpopulation is affected. Treatment with BTKi and CAR T cells provokes clearance of CLL cells in PB and spleen allowing MDSC recovery; suggesting this may be BTK and ITK independent. We continue to explore secondary lymphoid organs to further characterize the shift of the CLL microenvironment from an immunosuppressive to an immune effective one and its impact on immune function in this model. Disclosures Sanderson: Kite/Gilead: Honoraria. Gribben:Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Acerta/Astra Zeneca: Consultancy, Honoraria, Research Funding.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1134
Author(s):  
Won-Ju Kim ◽  
Gil-Ran Kim ◽  
Hyun-Jung Cho ◽  
Je-Min Choi

T cells are key immune cells involved in the pathogenesis of several diseases, rendering them important therapeutic targets. Although drug delivery to T cells is the subject of continuous research, it remains challenging to deliver drugs to primary T cells. Here, we used a peptide-based drug delivery system, AP, which was previously developed as a transdermal delivery peptide, to modulate T cell function. We first identified that AP-conjugated enhanced green fluorescent protein (EGFP) was efficiently delivered to non-phagocytic human T cells. We also confirmed that a nine-amino acid sequence with one cysteine residue was the optimal sequence for protein delivery to T cells. Next, we identified the biodistribution of AP-dTomato protein in vivo after systemic administration, and transduced it to various tissues, such as the spleen, liver, intestines, and even to the brain across the blood–brain barrier. Next, to confirm AP-based T cell regulation, we synthesized the AP-conjugated cytoplasmic domain of CTLA-4, AP-ctCTLA-4 peptide. AP-ctCTLA-4 reduced IL-17A expression under Th17 differentiation conditions in vitro and ameliorated experimental autoimmune encephalomyelitis, with decreased numbers of pathogenic IL-17A+GM-CSF+ CD4 T cells. These results collectively suggest the AP peptide can be used for the successful intracellular regulation of T cell function, especially in the CNS.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3781-3781
Author(s):  
Eolia Brissot ◽  
Sawa Ito ◽  
Kit Lu ◽  
Carly Cantilena ◽  
B. Douglas Smith ◽  
...  

Abstract Adult acute lymphoblastic leukemia (ALL) remains a therapeutic challenge with less than 40% long term survival. There is growing evidence that malignant diseases exert an “immune editing” effect which blocks antitumor immunity and permits tumor growth through immune evasion. Such tumor escape represents an obstacle for anticancer immunotherapy. In ALL such immune escape mechanisms are not well characterized. We therefore profiled cellular immunity in ALL, by characterizing the subsets of T cells, regulatory T cells (Treg), natural killers (NK) cells and γd T cells, using various functional markers including T cell exhaustion and NK cell activating or inhibitory molecules. Forty ALL patients were included in the study. The median age was 39 y (range, 18-75). Thirty-six presented with B-lineage ALL and 4 with T-lineage ALL. Mononuclear cells were isolated from blood (n=19) or bone marrow (n=21) at the onset of leukemia or at relapse. The median infiltration of blasts was 85% (range 24-96%). Healthy donor peripheral blood (n=12) and bone marrow (n=9), from age and gender matched population, were simultaneously analyzed as controls. Extra-and intra cellular staining were performed using using antibodies directed against CD3, CD4, CD8, CD45, CD45, CD45RA, CD45RO, CCR7, CD95, CD27, CD19, CD14, CD127, CD25, Foxp3, Helios, αβTCR, HLA-DR, CD117, CD20, CD10, CD22, CD34, LAG3, PD1, PDL1, CD56, NKG2A, NKG2C, NKG2D, KIR2DL1, KIR2DL3, CD57, CD33, CD11b, CD15, CD38 and CD24. Data were acquired on a BD LSRFORTESSA flow cytometer. The expression of programmed cell death 1 (PD-1, CD279) receptor on CD8+T cells was significantly increased in blood and bone marrow of ALL patients compared to healthy donors (p<0.0001 and p=0.004, respectively) (Fig. 1). Focusing on the different subsets, CD8+ effector memory T cells significantly over-expressed PD-1 in blood and bone marrow of ALL patients compared to healthy donors (p=0.008 and p=0.04, respectively). Moreover, there was a significant positive correlation between PD-1 expression on CD8+ effector memory T cells and blast infiltration (R2=0.23, 95%CI 0.026-0.76, p=0.04). Expression of the co-inhibitory receptor lymphocyte-activation gene 3 (LAG-3, CD223) was similar in ALL patients compared to healthy donors. A significantly higher frequency of T regulators (CD25+, CD127 low, Foxp3+) was found in bone marrow microenvironment in ALL patients (4.3% versus 1.6%, p=0.02). Concerning γd T cells, frequency was similar in blood and bone marrow of ALL patients compared with healthy donors. There was a significantly lower frequency of CD56dimNKG2A+KIR-CD57- (p=0.02) in the bone marrow of ALL patients indicating a maturation arrest. Interestingly, expression of the activating receptor NKG2D which plays an important role in triggering the NK cell–mediated tumor cell lysis was significantly reduced in NK cells of ALL patients while no difference in NK cell expression of NKG2C was found(Fig. 2). Adult patients with ALL show evidence of immune-editing of T cells and NK cells. This global immunosuppressive mechanism may contribute to the eventual escape of ALL from immune control. PD-1, overexpression, described in acute myeloid leukemia and chronic myeloid leukemia has been implicated in T-cell exhaustion and subsequent tumor immune evasion. Our data suggests similar immune escape mechanisms pertain in ALL. Effective antileukemia immunotherapy will require targeting one or more of these immunosuppressive pathways to achieve optimum results. Disclosures Fathi: Seattle Genetics, Inc.: Consultancy, Research Funding; Takeda pharmaceuticals International Co.: Research Funding; Exelixis: Research Funding; Ariad: Consultancy.


Blood ◽  
2011 ◽  
Vol 118 (13) ◽  
pp. 3528-3537 ◽  
Author(s):  
Maryam Ahmadi ◽  
Judith W. King ◽  
Shao-An Xue ◽  
Cécile Voisine ◽  
Angelika Holler ◽  
...  

Abstract The function of T-cell receptor (TCR) gene modified T cells is dependent on efficient surface expression of the introduced TCR α/β heterodimer. We tested whether endogenous CD3 chains are rate-limiting for TCR expression and antigen-specific T-cell function. We show that co-transfer of CD3 and TCR genes into primary murine T cells enhanced TCR expression and antigen-specific T-cell function in vitro. Peptide titration experiments showed that T cells expressing introduced CD3 and TCR genes recognized lower concentration of antigen than T cells expressing TCR only. In vivo imaging revealed that TCR+CD3 gene modified T cells infiltrated tumors faster and in larger numbers, which resulted in more rapid tumor elimination compared with T cells modified by TCR only. After tumor clearance, TCR+CD3 engineered T cells persisted in larger numbers than TCR-only T cells and mounted a more effective memory response when rechallenged with antigen. The data demonstrate that provision of additional CD3 molecules is an effective strategy to enhance the avidity, anti-tumor activity and functional memory formation of TCR gene modified T cells in vivo.


2019 ◽  
Author(s):  
Mirko Corselli ◽  
Suraj Saksena ◽  
Margaret Nakamoto ◽  
Woodrow E. Lomas ◽  
Ian Taylor ◽  
...  

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.


2018 ◽  
Vol 86 (9) ◽  
Author(s):  
Eileen A. Wong ◽  
Louis Joslyn ◽  
Nicole L. Grant ◽  
Edwin Klein ◽  
Philana Ling Lin ◽  
...  

ABSTRACTThe hallmarks of pulmonaryMycobacterium tuberculosisinfection are lung granulomas. These organized structures are composed of host immune cells whose purpose is to contain or clear infection, creating a complex hub of immune and bacterial cell activity, as well as limiting pathology in the lungs. Yet, given cellular activity and the potential for frequent interactions between host immune cells andM. tuberculosis-infected cells, we observed a surprisingly low quantity of cytokine-producing T cells (<10% of granuloma T cells) in our recent study ofM. tuberculosisinfection within nonhuman primate (NHP) granulomas. Various mechanisms could limit T cell function, and one hypothesis is T cell exhaustion. T cell exhaustion is proposed to result from continual antigen stimulation, inducing them to enter a state characterized by low cytokine production, low proliferation, and expression of a series of inhibitory receptors, the most common being PD-1, LAG-3, and CTLA-4. In this work, we characterized the expression of inhibitory receptors on T cells and the functionality of these cells in tuberculosis (TB) lung granulomas. We then used these experimental data to calibrate and inform an agent-based computational model that captures environmental, cellular, and bacterial dynamics within granulomas in lungs duringM. tuberculosisinfection. Together, the results of the modeling and the experimental work suggest that T cell exhaustion alone is not responsible for the low quantity ofM. tuberculosis-responsive T cells observed within TB granulomas and that the lack of exhaustion is likely an intrinsic property of granuloma structure.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2946-2946
Author(s):  
Scott R Best ◽  
Adam Kittai ◽  
Taylor Rowland ◽  
Nur Bruss ◽  
Stephen E Spurgeon ◽  
...  

Abstract Introduction: T cells from patients with CLL and lymphoma show highly impaired immune synapse formation, cytotoxic function, and adhesion and migration capabilities. Recent advances in immunooncology led to the emergence of therapeutic agents that permit reversal of T-cell exhaustion in cancer. However, rational development of novel combination approaches in immunotherapy requires detailed understanding of how targeted therapies influence T-cell function. We have shown that pevonedistat (TAK-924), an investigational NAE inhibitor, abrogates NFκB activation in CLL cells. Pevonedistat forms a covalent adduct with NEDD8, a ubiquitin-like modifier, thereby disrupting its interaction with NAE. This leads to reduced activity of Cullin-RING ligases (CRLs), a group of ubiquitin ligases that require modification by NEDD8 for their function. Ultimately, a decrease in CRL activity leads to reduced ubiquitination and proteasomal degradation of CRL substrates, extending the half-life of these proteins, including inhibitor of NFκB (IκB). Moreover, NFκB is critical in T-cell function. However, limited data exist on the effects of targeting neddylation on T-cell response. Here, we demonstrate that targeting neddylation in vitro preserves T-cell functionality and may lead to favorable T-cell population shifts in CLL. Methods: Peripheral blood mononuclear cells were isolated from patients with CLL (n=50), and T cells were purified using Dynabeads. Pevonedistat was obtained from Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (Cambridge, MA). Results: In vitro T-cell receptor (TCR; CD3/CD28) stimulation induced T-cell activation and proliferation. Continuous treatment of T cells with pevonedistat led to rapid (2 hour) disruption of cullin neddylation, followed by a significant reduction in activity of NFκB and NFAT as assessed by immunoblotting and immunofluorescence. Despite this reduction, CD4 and CD8 T cells continued to respond to TCR stimulation, with relative abundance of early markers of activation (CD40L, CD69). However, we observed reduced expression of CD25 and PD-1 at 72 hours. Continuous treatment with pevonedistat led to a dose-dependent decrease in IL-2 secretion and reduced proliferation of the CD4 T-cell subset (CFSE, Ki-67) but did not induce apoptosis. Unlike CLL cells, CD4 T cells did not undergo DNA re-replication and G2/M arrest in response to pevonedistat. We further analyzed T-cell subsets following TCR stimulation. Concurrent treatment with pevonedistat led to an increase in IFNγ-secreting CD4 T cells, whereas IL-4 production decreased, suggesting a shift toward the Th1 phenotype. Furthermore, we observed a robust decrease of the iTreg population, accompanied by downregulation of FoxP3 mRNA and protein within the CD4 T-cell subset, indicating that targeting neddylation may help to reverse the immunosuppressive phenotype in CLL. To mimic the in vivo pharmacokinetics of pevonedistat, we performed drug washouts where CLL-derived T cells were exposed to 2-hour pulse treatment with 1 µM pevonedistat prior to TCR stimulation. Under these conditions, cullin neddylation and NFκB activity began to recover by 8 hours, with near complete recovery by 24 hours. Moreover, pevonedistat did not disrupt allogeneic (OCI-LY19 cells) or autologous (CD40L-stimulated CLL cells) T-cell cytotoxicity. Meanwhile, CD8 T cells continued to produce perforin and granzyme B. Conclusions: Our data suggest that pharmacologic targeting of NAE preserves T-cell cytotoxic function and may enhance anti-tumor immunity in CLL. Combined with our earlier reports that targeting NAE kills CLL cells under lymph node-mimicking conditions, these data provide a strong rationale for continued investigation of pevonedistat in CLL and lymphoid malignancies. Disclosures Spurgeon: Bristol Myers Squibb: Research Funding; Gilead Sciences, Inc.: Consultancy, Research Funding; Oncternal: Research Funding; Acerta: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Pharmacyclics: Consultancy, Research Funding; MEI Pharma: Consultancy. Berger:Takeda Pharmaceuticals International Co.: Employment. Danilov:Gilead Sciences: Consultancy, Research Funding; Astra Zeneca: Consultancy; Verastem: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Aptose Biosciences: Research Funding; Takeda Oncology: Research Funding; TG Therapeutics: Consultancy; Bayer Oncology: Consultancy, Research Funding.


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