Ibrutinib Is an Irreversible Molecular Inhibitor of Interleukin-2 Inducible Kinase: Expanding Therapeutic Potential and Modulating a Th1 Selective Pressure in CD4 T-Cells

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 775-775 ◽  
Author(s):  
Jason A Dubovsky ◽  
Kyle A Beckwith ◽  
Jennifer A. Woyach ◽  
Samantha M. Jaglowski ◽  
Joshua Hessler ◽  
...  

Abstract Abstract 775 In chronic lymphocytic leukemia (CLL), mounting evidence points to an aberrant tumor associated Th2 bias that drives leukemic cell immune evasion, promotes formation of a supportive niche microenvironment, and functionally cripples innate and adaptive immunity. The end result is a high incidence of infections which is the primary cause of mortality in CLL. This same Th2 bias is induced by many other types of cancer. Th2 CD4 T-cells are singularly dependent upon IL-2-inducible T-cell kinase (ITK) for activation whereas Th1 CD4 and CD8 T-cells have compensatory resting lymphocyte kinase (RLK) which conducts T-cell receptor activation even in the absence of ITK. Thus, a clinically viable ITK inhibitor would be ideal for targeting immune suppression associated with CLL and potentially other types of cancer. Unfortunately, no such therapeutic is currently available. Ibrutinib, a confirmed inhibitor of the Bruton's tyrosine kinase (BTK) that irreversibly blocks downstream B-cell receptor activation, has demonstrated outstanding clinical activity in phase I/II clinical trials resulting in durable remissions in CLL. Our studies unveiled a previously uncharacterized Th1 cytokine switch in ibrutinib treated CLL patients which could not be attributed to B-lymphocytes. This ibrutinib-induced Th1 T-cell skewing was confirmed using the EμTCL1 mouse model of leukemia. Such alterations in cytokine patterns were reminiscent of mouse studies in which genetic ablation of ITK subverted Th2 immunity, thereby potentiating Th1-based adaptive immunity. The striking homology between BTK and ITK combined with intriguing in silico docking studies and promising in vitro kinase inhibition profiles with ibrutinib led to the hypothesis that this could be the first clinically viable irreversible ITK inhibitor. Cellular probe assays confirmed that the active site of ITK was covalently blocked by ibrutinib at pharmacologically relevant doses. Our comprehensive molecular analyses of T-cell signaling confirmed this in the Jurkat cell line. We further confirmed both molecular and functional outcomes in primary and in vitro polarized Th1 and Th2 CD4 T-cells. We found that mutation of the ITK-Cys442 covalent binding residue for ibrutinib alleviated molecular inhibition. We also demonstrated that Th1 and CD8 T-cell restricted expression of RLK provides a compensatory platform for T-cell activation offering a molecular explanation for the selective outgrowth of cytotoxic Th1 biased immunity. We further confirmed this effect using T-cells directly derived from CLL patients. To demonstrate that ibrutinib-induced ITK inhibition had direct clinical relevance in the setting of CLL we utilized a novel listeriosis/leukemia mouse model. In this model we clearly demonstrated complete recovery of functional immunity and all ibrutinib treated mice survived a potentially lethal Listeria monocytogenes infection. Our results expose novel molecular insights into the mechanism of action of ibrutinib in the context of Th2-biased immunosuppressive leukemia. We also postulate that ibrutinib's irreversible ITK inhibitory effects may prove effective in a number of other autoimmune, inflammatory, and viral diseases, including influenza A and HIV/AIDS. Disclosures: Jaglowski: Pharmacyclics: Research Funding. Chang:Pharmacyclics, Inc.: Employment. Maddocks:Pharmacyclics: Research Funding. Buggy:Pharmacyclics: Employment, Equity Ownership. Byrd:Pharmacyclics: Research Funding.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4313-4313
Author(s):  
Scott R Best ◽  
Vi Lam ◽  
Nur Bruss ◽  
Taylor Hashiguchi Rowland ◽  
Adam S. Kittai ◽  
...  

Introduction: Inhibitors of B-cell receptor associated kinases (e.g., Bruton tyrosine kinase and phoshpoinotiside-3 kinase) have led to significant improvement in outcomes of patients with CLL. Furthermore, such therapies have immunomodulatory effects. This is particularly relevant given that T cells from patients with CLL are functionally compromised and demonstrate impaired immune synapse formation, adhesion, migration and cytotoxicity. It is critical to improve understanding of the immunomodulatory properties of the novel agents as this will help understand their effect on the immune system in CLL, mitigate toxicities as well as inform future drug development. Pevonedistat, (MLN4924) forms an irreversible covalent adduct with NEDD8, a ubiquitin-like modifier, thereby inhibiting the NEDD8-activating enzyme (NAE). This leads to decreased neddylation and reduced activity of cullin-RING E3 ubiquitin ligases (CRLs). 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). We have shown that pevonedistat abrogates NFκB activation in CLL cells. Importantly, NFκB activation is indispensable in T-cell activation. However, there is paucity of data regarding the immune effects of targeting neddylation. Here we address this knowledge gap and demonstrate that NAE inhibition may have favorable immunomodulatory effects in CLL. Methods: Peripheral blood mononuclear cells were isolated from patients with CLL and T cells were purified using Dynabeads. Pevonedistat was provided by Millennium Pharmaceuticals, Inc. (Cambridge, MA). For gene expression analysis, FACS-sorted naïve CD4+ T cells were pre-treated with pevonedistat for 1 hour prior to T-cell receptor (TCR; αCD3/CD28) stimulation; RNA was harvested 3 or 24 hours after stimulation and analyzed on a Clariom S microarray chip. For polarization assays, FACS-sorted naïve CD4+ T cells were TCR-activated for 7 days under Th1/2/17/Treg-differentiation conditions. BALB/c mice were administered 60 mg/kg pevonedistat SC twice weekly for 3 weeks and T cell populations were analyzed by flow cytometry. Results: In vitro treatment of T cells with pevonedistat led to rapid reduction in neddylated cullins and stabilization of pIκBα. NAE inhibition did not impede proximal TCR signaling following TCR stimulation (pZAP70, pERK). GSEA demonstrated downmodulation of NFκB and IL-2 signaling pathways in pevonedistat-treated cells by 3 h. Despite this, CD4/CD8+ T cells exhibited normal induction of early activation markers (CD40L, CD69). By contrast, we observed reduced expression of CD38, HLA-DR and PD-1 and diminished CD25 following continuous treatment with pevonedistat for 72 h. This was accompanied by dose-dependent decrease in IL-2 secretion and reduced proliferation of the CD4/CD8+ T cell subsets (CFSE), but no apoptosis. Sorted naive T cells treated with pevonedistat in Th/Treg polarizing conditions exhibited an increase in IFNγ secretion and a decrease in IL-4, suggesting a shift toward Th1 phenotype. Furthermore, we observed a robust decrease of the inducible Treg (iTreg) FoxP3+ population. Loss of iTregs was accompanied by ablated IL-2/STAT5 signaling. Concurrently, we observed a modest increase in Th17 subpopulation following NAE inhibition. We found increased expression of HIF-1α, a CRL target, in pevonedistat-treated T cells, which may have contributed to this phenomenon. To mimic the clinical pharmacokinetics of pevonedistat, we performed 2 h pulse treatment with pevonedistat prior to TCR stimulation. Under these conditions NFκB activity fully recovered by 24 h. Importantly, allogeneic (OCI-LY19 cells) and autologous (CD40L-stimulated CLL cells) T-cell cytotoxicity, perforin and granzyme B production were not disrupted by NAE inhibition. In vivo administration of pevonedistat in immunocompetent BALB/c mice resulted in a decrease of Treg population, confirming in vitro data. Conclusions: Our data suggest that targeting neddylation may help rebalance T cells towards healthy immune subsets in CLL via the reduction of the Treg/Th2 phenotypes. 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 Berger: Millennium Pharmaceuticals, Inc., Cambridge, MA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Danilov:TG Therapeutics: Consultancy; Takeda Oncology: Research Funding; MEI: Research Funding; Verastem Oncology: Consultancy, Other: Travel Reimbursement , Research Funding; AstraZeneca: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Seattle Genetics: Consultancy; Gilead Sciences: Consultancy, Research Funding; Bristol-Meyers Squibb: Research Funding; Aptose Biosciences: Research Funding; Bayer Oncology: Consultancy, Research Funding; Celgene: Consultancy; Curis: Consultancy; Abbvie: Consultancy; Pharmacyclics: Consultancy; Janssen: Consultancy.


2002 ◽  
Vol 196 (4) ◽  
pp. 481-492 ◽  
Author(s):  
Kristin V. Tarbell ◽  
Mark Lee ◽  
Erik Ranheim ◽  
Cheng Chi Chao ◽  
Maija Sanna ◽  
...  

Glutamic acid decarboxylase (GAD)65 is an early and important antigen in both human diabetes mellitus and the nonobese diabetic (NOD) mouse. However, the exact role of GAD65-specific T cells in diabetes pathogenesis is unclear. T cell responses to GAD65 occur early in diabetes pathogenesis, yet only one GAD65-specific T cell clone of many identified can transfer diabetes. We have generated transgenic mice on the NOD background expressing a T cell receptor (TCR)-specific for peptide epitope 286–300 (p286) of GAD65. These mice have GAD65-specific CD4+ T cells, as shown by staining with an I-Ag7(p286) tetramer reagent. Lymphocytes from these TCR transgenic mice proliferate and make interferon γ, interleukin (IL)-2, tumor necrosis factor (TNF)-α, and IL-10 when stimulated in vitro with GAD65 peptide 286–300, yet these TCR transgenic animals do not spontaneously develop diabetes, and insulitis is virtually undetectable. Furthermore, in vitro activated CD4 T cells from GAD 286 TCR transgenic mice express higher levels of CTL-associated antigen (CTLA)-4 than nontransgenic littermates. CD4+ T cells, or p286-tetramer+CD4+ Tcells, from GAD65 286–300-specific TCR transgenic mice delay diabetes induced in NOD.scid mice by diabetic NOD spleen cells. This data suggests that GAD65 peptide 286–300-specific T cells have disease protective capacity and are not pathogenic.


Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 580-588 ◽  
Author(s):  
Kathrin Gollmer ◽  
François Asperti-Boursin ◽  
Yoshihiko Tanaka ◽  
Klaus Okkenhaug ◽  
Bart Vanhaesebroeck ◽  
...  

Abstract CD4+ T cells use the chemokine receptor CCR7 to home to and migrate within lymphoid tissue, where T-cell activation takes place. Using primary T-cell receptor (TCR)–transgenic (tg) CD4+ T cells, we explored the effect of CCR7 ligands, in particular CCL21, on T-cell activation. We found that the presence of CCL21 during early time points strongly increased in vitro T-cell proliferation after TCR stimulation, correlating with increased expression of early activation markers. CCL21 costimulation resulted in increased Ras- and Rac-GTP formation and enhanced phosphorylation of Akt, MEK, and ERK but not p38 or JNK. Kinase-dead PI3KδD910A/D910A or PI3Kγ-deficient TCR-tg CD4+ T cells showed similar responsiveness to CCL21 costimulation as control CD4+ T cells. Conversely, deficiency in the Rac guanine exchange factor DOCK2 significantly impaired CCL21-mediated costimulation in TCR-tg CD4+ T cells, concomitant with impaired Rac- but not Ras-GTP formation. Using lymph node slices for live monitoring of T-cell behavior and activation, we found that G protein-coupled receptor signaling was required for early CD69 expression but not for Ca2+ signaling. Our data suggest that the presence of CCL21 during early TCR signaling lowers the activation threshold through Ras- and Rac-dependent pathways leading to increased ERK phosphorylation.


PLoS ONE ◽  
2014 ◽  
Vol 9 (11) ◽  
pp. e112242 ◽  
Author(s):  
Ghanashyam Sarikonda ◽  
Georgia Fousteri ◽  
Sowbarnika Sachithanantham ◽  
Jacqueline F. Miller ◽  
Amy Dave ◽  
...  

2009 ◽  
Vol 206 (3) ◽  
pp. 507-514 ◽  
Author(s):  
Cédric Louvet ◽  
Beniwende G. Kabre ◽  
Dan W. Davini ◽  
Nicolas Martinier ◽  
Maureen A. Su ◽  
...  

Autoimmune-prone nonobese diabetic mice deficient for B7-2 spontaneously develop an autoimmune peripheral neuropathy mediated by inflammatory CD4+ T cells that is reminiscent of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy. To determine the etiology of this disease, CD4+ T cell hybridomas were generated from inflamed tissue–derived CD4+ T cells. A majority of T cell hybridomas were specific for myelin protein 0 (P0), which was the principal target of autoantibody responses targeting nerve proteins. To determine whether P0-specific T cell responses were sufficient to mediate disease, we generated a novel myelin P0–specific T cell receptor transgenic (POT) mouse. POT T cells were not tolerized or deleted during thymic development and proliferated in response to P0 in vitro. Importantly, when bred onto a recombination activating gene knockout background, POT mice developed a fulminant form of peripheral neuropathy that affected all mice by weaning age and led to their premature death by 3–5 wk of age. This abrupt disease was associated with the production of interferon γ by P0-specific T cells and a lack of CD4+ Foxp3+ regulatory T cells. Collectively, our data suggest that myelin P0 is a major autoantigen in autoimmune peripheral neuropathy.


1992 ◽  
Vol 176 (4) ◽  
pp. 1091-1098 ◽  
Author(s):  
R A Seder ◽  
W E Paul ◽  
M M Davis ◽  
B Fazekas de St Groth

To study the factors that determine whether CD4+ T cells produce interleukin 4 (IL-4) or interferon gamma (IFN-gamma) upon stimulation we used a system allowing naive T cells to be primed in vitro by specific antigen. Dense CD4+ T cells were purified from mice that expressed transgenes encoding a T cell receptor specific for pigeon cytochrome C peptide 88-104 in association with I-Ek. These T cells produced very limited amounts of IL-4 and IFN-gamma upon immediate challenge with 88-104 and antigen-presenting cells (APC). However, after an initial "priming" culture in which they were incubated for 4 d in the presence of 88-104, APC, and 1,000 U/ml IL-4, the T cells acquired the capacity to produce substantial amounts of IL-4 upon rechallenge but made very little IFN-gamma. Cells primed in the absence of IL-4 produced IFN-gamma upon rechallenge but virtually no IL-4. The inhibitory effect of IL-4 on IFN-gamma production did not appear to be mediated by the induction of IL-10 production since IL-10 addition to initial cultures did not suppress priming for IFN-gamma production, nor did anti-IL-10 block the inhibitory effect of IL-4. IFN-gamma itself did not increase priming for IFN-gamma production, nor did anti-IFN-gamma reduce such priming. IFN-gamma did, however, diminish priming for IL-4 production when limiting amounts of IL-4 (100 U/ml) were used in the initial culture. The dominant effect of IL-4 in determining the lymphokine-producing phenotype of primed cells was observed with dendritic cells (DC), activated B cells, and I-Ek-transfected fibroblasts as APC. However, the different APC did vary in their potency, with DC being superior to activated B cells, which were superior to transfected fibroblasts.


Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3039
Author(s):  
Mikołaj Nawrocki ◽  
Niels Lory ◽  
Tanja Bedke ◽  
Friederike Stumme ◽  
Björn-Phillip Diercks ◽  
...  

Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most potent Ca2+ mobilizing agent and its inhibition proved to inhibit T-cell activation. However, the impact of the NAADP signaling on CD4+ T-cell differentiation and plasticity and on the inflammation in tissues other than the central nervous system remains unclear. In this study, we used an antagonist of NAADP signaling, trans-Ned 19, to study the role of NAADP in CD4+ T-cell differentiation and effector function. Partial blockade of NAADP signaling in naïve CD4+ T cells in vitro promoted the differentiation of Th17 cells. Interestingly, trans-Ned 19 also promoted the production of IL-10, co-expression of LAG-3 and CD49b and increased the suppressive capacity of Th17 cells. Moreover, using an IL-17A fate mapping mouse model, we showed that NAADP inhibition promotes conversion of Th17 cells into regulatory T cells in vitro and in vivo. In line with the results, we found that inhibiting NAADP ameliorates disease in a mouse model of intestinal inflammation. Thus, these results reveal a novel function of NAADP in controlling the differentiation and plasticity of CD4+ T cells.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 657-657
Author(s):  
Johannes Adrian Hildebrand ◽  
Deepak Bararia ◽  
Sebastian Stolz ◽  
Sarah Haebe ◽  
Stefan Alig ◽  
...  

The highly variable clinical course of follicular lymphoma (FL) is determined by the molecular heterogeneity of the tumor cells and complex interactions with the microenvironment. Here, we provide biochemical, structural, functional and clinical evidence that aberrant Cathepsin S (CTSS) activity induces a supportive immune microenvironment in FL. By targeted DNA sequencing of 305 diagnostic FL biopsies, we identified somatic mutations of CTSS in 8% of cases (24/305), mostly clustered at Y132 (19/24) converting Y to D (16/19). A subset of CTSS Y132 mutations (N=5) occurred at lower variant allele frequencies (5-10%), indicating subclonality. Another 13% of FL had CTSS amplifications (37/286). CTSS Y132 mutations and CTSS amplifications were mutually exclusive. In a cohort of 51 FL, CTSS amplifications were associated with higher CTSS expression (P=0.05). Of note, a subset of FL without CTSS amplifications also had higher CTSS expression, suggesting additional mechanisms of transcriptional dysregulation. CTSS is a cysteine protease that is highly expressed in endolysosomes of antigen presenting cells and malignant B-cells. CTSS is involved in proteolytical processing of antigenic peptides for presentation on MHC-II to be recognized by antigen specific CD4+ T-cells. CTSS is synthesized as an inactive zymogen, which is converted to its active form by autocatalytic cleavage of the autoinhibitory propeptide (pro-CTSS). We used CRISPR/Cas9 to introduce CTSS Y132D into Karpas422, a B-cell lymphoma cell line that harbors the FL hallmark translocation t(14;18). Single-cell derived Y132D mutant clones showed >3-fold higher ratios of active CTSS to pro-CTSS (N=4, P=0.0003). Immunoprecipitated CTSS Y132D had >3-fold higher in vitro substrate cleavage activity compared to CTSS wild type (WT) (N=6, P=0.001). We purified pro-CTSS WT and Y132D and assayed their in vitro autocatalytic cleavage over time. The time required to convert 50% of pro-CTSS decreased from 17 minutes for WT to 11 minutes for Y132D (N=3, P=0.04). In contrast, purified active CTSS WT and Y132 had similar in vitro cleavage activities. Molecular dynamics simulations showed that the Y132D mutation shortens the distances by ~2Å between the catalytic triad of active CTSS (C139, H278, N298) and a stretch of amino acids from the proform (L80, G81, D82, S94), which may facilitate intramolecular cleavage. By mass spectrometry we could indeed detect novel intermediate-sized CTSS fragments. Thus, Y132D does not increase the activity of the mature enzyme but is a gain-of-function mutation by accelerating the conversion from pro-CTSS to catalytically active CTSS. CD74 (invariant chain) is a physiologic CTSS substrate that plays critical roles in the assembly, trafficking and stabilization of peptide-free MHC-II. CTSS cleaves CD74, thereby allowing binding and presentation of antigens on MHC-II to antigen specific CD4+ T-cells. We could show that CTSS Y132D enhanced CD74 cleavage in Karpas422 cells. We then tested the impact of CTSS on antigen specific CD4+ T-cell activation in co-culture assays. CTSS knock-out lymphoma cells were broadly incapable of activating CD4+ T-cells. Overexpression of CTSS WT activated CD4+ T-cells more efficiently compared to empty vector control. CTSS Y132 had the highest capacity to stimulate antigen specific CD4+ T-cell responses. Furthermore, in primary FL biopsies (N=51) CTSS Y132 mutations had gene expression profiles linked with antigen-processing and chemokine perturbation, including CXCL13, a B-cell chemoattractant produced by activated CD4+ T-follicular helper cells. Lastly, we aimed to correlate CTSS aberrations with clinical outcome in patients who received standard immunochemotherapy (R-CHOP) for advanced FL (N=51 with available CTSS mutation and gene expression data). Compared to all other patients (N=34), patients with CTSS Y132 mutations or CTSS overexpression (N=17) had longer failure free survival (P=0.012) and overall survival (P=0.041). In summary, we propose that aberrant CTSS activity - even if only present in a FL subclone - can elicit a CD4+ T-cell driven tumor-promoting immune response, which could be amplified within the microenvironment via pro-inflammatory and chemotactic cytokines and substantially impact the biology and clinical course of the disease. Thus, aberrant CTSS activity is a promising biomarker and therapeutic target in FL and potentially also other tumors. Disclosures Klapper: Roche, Takeda, Amgen, Regeneron: Honoraria, Research Funding. Hiddemann:Bayer: Research Funding; Roche: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Vector Therapeutics: Consultancy, Honoraria. Steidl:Juno Therapeutics: Consultancy; Bristol-Myers Squibb: Research Funding; Nanostring: Patents & Royalties: Filed patent on behalf of BC Cancer; Roche: Consultancy; Tioma: Research Funding; Seattle Genetics: Consultancy; Bayer: Consultancy. Kridel:Gilead Sciences: Research Funding. Weinstock:Celgene: Research Funding; Verastem Oncology: Research Funding. Weigert:Novartis: Research Funding; Roche: Research Funding.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3719-3719
Author(s):  
Vi Lam ◽  
Xiaoguang Wang ◽  
Scott R Best ◽  
Nur Bruss ◽  
Tingting Liu ◽  
...  

Abstract Introduction: CLL is characterized by deficient immunity which clinically manifests as increased predisposition towards malignancies and infectious complications. T-cells from patients with CLL exhibit a skewed repertoire with predominance of Tregs as well as impaired immune synapse formation and cytotoxic function. Small ubiquitin-like modifier (SUMO) family proteins regulate a variety of cellular processes, including nuclear trafficking, gene transcription and cell cycle progression, via post-translational modification of target proteins. Sumoylation regulates NFκB signaling, IFN response and NFAT activation, processes indispensable in immune cell activation. Despite this, the role of sumoylation in T cell biology in context of cancer is not known. TAK-981 is a small molecule inhibitor of the SUMO-activating enzyme (SAE) that forms a covalent adduct with an activated SUMO protein, thereby preventing its transfer to the SUMO-conjugating enzyme (Ubc9). Here, we investigated the immunomodulatory effects of TAK-981 in CLL. Methods: T cells from patients with CLL were purified using Dynabeads. For polarization assays, FACS-sorted naïve CD4+ T cells were cultured for 7 days in control or differentiation media. For gene expression profiling (GEP; Clariom S), RNA was harvested after 3 and 24 hours of TCR engagement from FACS-sorted naïve CD4+ T cells. For in vivo immunization experiments, CD4+KJ1-26+ cells were inoculated IV into BALB/cJ mice. Mice received 100 µg IV ovalbumin ± R848 followed by TAK-981 7.5 mg/kg or vehicle control IV twice weekly for 10 days prior to spleen collection. Both recipient and transplanted splenocytes were analyzed. For analysis of tumor-infiltrating lymphocytes (TILs), BALB/c mice were injected with 1x10 6 A20 lymphoma cells and treated as above. TAK-981 was provided by Millennium Pharmaceuticals, Inc. (Cambridge, MA). Results: T cells from patients with CLL demonstrated high baseline protein sumoylation that slightly increased following TCR engagement (αCD3/CD28). Treatment with TAK-981 significantly downregulated SUMO1 and SUMO2/3-modified protein levels yet did not disrupt early TCR signaling as evidenced by sustained ZAP70, p65/NFκB and NFAT activation detected by immunoblotting, immunocytochemistry and GEP. Treatment with TAK-981 resulted in dose-dependent upregulation of the early activation marker CD69 in CD4 + T cells following 72 and 96 hours of TCR stimulation vs. control. Meanwhile, expression of CD25, HLA-DR and CD40L was delayed in the presence of TAK-981. Interestingly, CD38, an IFN response target, was induced two-fold in TAK-981-treated cells after 24 hours and persisted at high levels at subsequent timepoints. T cell proliferation was reduced in the presence of high (1 μM) but not low/intermediate concentrations of TAK-981, accompanied by reduced S phase entry and decreased synthesis of IL-2. However, T cells did not undergo apoptosis under those conditions. Targeting SAE in either control or Th1/Treg polarizing conditions facilitated an increase in IFNγ and loss of FoxP3 expression (accompanied by decreased IL-2/STAT5), suggesting a shift towards Th1 and away from Treg phenotype, respectively. GEP (Reactome, GSEA) confirmed a dramatically upregulated IFN response in TAK-981-treated CD4 + naïve T cells. Furthermore, targeting SAE enhanced degranulation (CD107a), IFNγ and perforin secretion in cytotoxic CD8+ T cells and potentiated T cell cytotoxicity in allogeneic assays with lymphoma cells (OCI-LY3, U2932) as targets. Consistent with our in vitro data, OVA-stimulated transplanted transgenic KJ1-26+ splenocytes, as well as total CD4+ T cells from recipient mice treated with TAK-981 in vivo exhibited a significant reduction in expression of FoxP3 and an increased production of IFNγ (Figure 1). In the A20 syngeneic model, treatment with TAK-981 similarly downregulated FoxP3 expression in CD4+ TILs and induced IFNγ secretion in CD8+ TILs. Conclusion. Using a combination of in vitro and in vivo experiments, we demonstrate that pharmacologic targeting of sumoylation with TAK-981 does not impair proximal TCR signaling in T cells obtained from patients with CLL, but leads to rebalancing toward healthy immune T cell subsets via induction of IFN response and downmodulation of Tregs. These data provide a strong rationale for continued investigation of TAK-981 in CLL and lymphoid malignancies. Figure 1 Figure 1. Disclosures Siddiqi: Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; TG Therapeutics: Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncternal: Research Funding; Janssen: Speakers Bureau; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Danilov: SecuraBio: Research Funding; Bayer Oncology: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Takeda Oncology: Research Funding; TG Therapeutics: Consultancy, Research Funding; Rigel Pharm: Honoraria; Abbvie: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; Gilead Sciences: Research Funding; Bristol-Meyers-Squibb: Honoraria, Research Funding; Astra Zeneca: Consultancy, Honoraria, Research Funding.


2000 ◽  
Vol 192 (8) ◽  
pp. 1125-1134 ◽  
Author(s):  
Jinfang Zhu ◽  
Hua Huang ◽  
Liying Guo ◽  
Timothy Stonehouse ◽  
Cynthia J. Watson ◽  
...  

Interleukin (IL)-4 and IL-12 together with T cell receptor (TCR) engagement are crucial for the differentiation of CD4+ T cells into T helper (Th)2 or Th1 cells, respectively. Although IL-4 receptors (IL-4Rs) but not IL-12Rs are expressed on naive CD4+ T cells, IL-4 has no apparent advantage over IL-12 in driving naive T cell differentiation when the cells are primed with both IL-4 and IL-12 in vitro. It was found that IL-4–induced phosphorylation of Janus kinases 1 and 3, IL-4Rα, signal transducer and activator of transcription 6, and insulin receptor substrate 2 was strikingly but transiently inhibited by TCR ligation both in conventional and TCR transgenic T cells. TCR engagement also blocked the expression of an IL-4–inducible gene. Signals induced by other cytokines, including IL-2, IL-6, and interferon α, but not by insulin-like growth factor 1, were also blocked by TCR engagement. The capacity of various inhibitors to reverse TCR-mediated inhibition of IL-4 signaling suggested that activation of the Ras–mitogen-activated protein kinase pathway and of the calcineurin pathway contribute to desensitizing IL-4R. IL-4 responsiveness returned at about the time (∼12 h) that IL-12–mediated signaling was first observed. Thus, through different mechanisms, neither IL-4R nor IL-12R has any clear advantage in polarizing cells; rather, the availability of cytokine is probably the limiting factor in this process.


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