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Selective disruption of TLR2/MyD88 interaction inhibits inflammation and attenuates Alzheimer’s pathology

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Abstract

Induction of TLR2 activation depends on its association with adapter protein MyD88. We have found that levels of TLR2 and MyD88 are elevated in the hippocampus and cortex of Alzheimer’s disease (AD) patients and 5XFAD mouse model of AD. Since there is no specific inhibitor of TLR2, to target induced TLR2 from therapeutic angle, we engineered a peptide corresponding to the TLR2-interacting domain of MyD88 (TIDM) that binds to the BB loop of only TLR2, but not other TLRs. Interestingly, wild type (wt) TIDM peptide inhibited microglial activation induced by fibrillar Aβ1-42 and lipoteichoic acid, but not 1-methyl-4-phenylpyridinium, double-stranded RNA, bacterial lipopolysaccharide, flagellin, and CpG DNA. After intranasal administration, wtTIDM peptide reached the hippocampus, reduced hippocampal glial activation, lowered Aβ burden, attenuated neuronal apoptosis, and improved memory and learning in 5XFAD mice. However, wtTIDM peptide was not effective in 5XFAD mice lacking TLR2. In addition to 5XFAD mice, wtTIDM peptide also suppressed the disease process in mice with experimental allergic encephalomyelitis and collagen-induced arthritis. Therefore, selective targeting of activated status of one component of the innate immune system by wtTIDM peptide may be beneficial in AD as well as other disorders in which TLR2-MyD88 signaling plays a role in disease pathogenesis.

Authors

Suresh B. Rangasamy, Malabendu Jana, Avik Roy, Grant T. Corbett, Madhuchhanda Kundu, Sujyoti Chandra, Susanta Mondal, Sridevi Dasarathi, Elliott J. Mufson, Rama K. Mishra, Chi-Hao Luan, David A. Bennett, Kalipada Pahan

Hgf/Met activation mediates resistance to BRAF inhibition in murine anaplastic thyroid cancers

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Abstract

Anaplastic thyroid carcinomas (ATC) have a high prevalence of BRAF and TP53 mutations. A trial of vemurafenib in non-melanoma BRAFV600E-mutant cancers showed significant, although short-lived, responses in ATCs, indicating that these virulent tumors remain addicted to BRAF despite their high mutation burden. To explore the mechanisms mediating acquired resistance to BRAF blockade we generated mice with thyroid-specific deletion of p53 and dox-dependent expression of BRAFV600E, 50% of which developed ATCs after dox treatment. Upon dox withdrawal there was complete regression in all mice, although recurrences were later detected in 85% of animals. The relapsed tumors had elevated MAPK transcriptional output, and retained responses to the MEK/RAF inhibitor CH5126766 in vivo and in vitro. Whole exome sequencing identified recurrent focal amplifications of chromosome 6, with a minimal region of overlap that included Met. Met-amplified recurrences overexpressed the receptor as well as its ligand Hgf. Growth, signaling and viability of Met-amplified tumor cells were suppressed in vitro and in vivo by the Met kinase inhibitors PF-04217903 and crizotinib, whereas primary ATCs and Met-diploid relapses were resistant. Hence, recurrences are the rule after BRAF suppression in murine ATCs, most commonly due to activation of HGF/MET signaling, which generates exquisite dependency to MET kinase inhibitors.

Authors

Jeffrey A. Knauf, Kathleen A. Luckett, Kuen-Yuan Chen, Francesca Voza, Nicholas D. Socci, Ronald Ghossein, James A. Fagin

Inherited p40^phox deficiency differs from classic chronic granulomatous disease

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Abstract

Bi-allelic loss-of-function mutations of the NCF4 gene, encoding the p40phox subunit of the phagocyte NADPH oxidase, have been described in only one patient. We report 24 p40phox-deficient patients from 12 additional families in eight countries. These patients display eight different in-frame or out-of-frame mutations of NCF4, homozygous in 11 families and compound heterozygous in another. When overexpressed in NB4 neutrophil-like cells and EBV-transformed B cells in vitro, the mutant alleles were found to be loss-of-function, with the exception of the p.R58C and c.120_134del alleles, which were hypomorphic. Particle-induced NADPH oxidase activity was subnormal in the patients’ neutrophils, whereas PMA-induced DHR oxidation, which is widely used as a diagnostic test for CGD, was normal in some of the patients. Moreover, the NADPH oxidase activity of EBV-transformed B cells was also subnormal, whereas that of mononuclear phagocytes was normal. Finally, the killing of Candida albicans and Aspergillus fumigatus hyphae by neutrophils was conserved in these patients. The patients described here suffer from hyperinflammation and peripheral infections, but they do not display any of the invasive bacterial and fungal infections seen in CGD. In conclusion, inherited p40phox deficiency underlies a distinctive condition, resembling a mild, atypical form of CGD

Authors

Annemarie van de Geer, Alejandro Nieto-Patlán, Douglas B. Kuhns, Anton T.J. Tool, Andrés A. Arias, Matthieu Bouaziz, Martin de Boer, José Luis Franco, Roel P. Gazendam, John L. van Hamme, Michel van Houdt, Karin van Leeuwen, Paul J.H. Verkuijlen, Timo K. van den Berg, Juan F. Alzate, Carlos A. Arango-Franco, Vritika Batura, Andrea R. Bernasconi, Barbara Boardman, Claire Booth, Siobhan O. Burns, Felipe Cabarcas, Nadine Cerf Bensussan, Fabienne Charbit-Henrion, Anniek Corveleyn, Caroline Deswarte, María Esnaola Azcoiti, Dirk Foell, John I. Gallin, Carlos Garcés, Margarida Guedes, Claas H. Hinze, Steven M. Holland, Stephen M. Hughes, Patricio Ibañez, Harry L. Malech, Isabelle Meyts, Marcela Moncada-Velez, Kunihiko Moriya, Esmeralda Neves, Matias Oleastro, Laura Perez, Vimel Rattina, Carmen Oleaga-Quintas, Neil Warner, Aleixo M. Muise, Jeanet Serafin López, Eunice Trindade, Julia Vasconselos, Severine Vermeire, Helmut Wittkowski, Austen Worth, Laurent Abel, Mary C. Dinauer, Peter D. Arkwright, Dirk Roos, Jean-Laurent Casanova, Taco W. Kuijpers, Jacinta Bustamante

Platelet-RBC interaction mediated by FasL-FasR induces procoagulant activity important for thrombosis

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Abstract

Red blood cells (RBCs) influence rheology, release ADP, ATP and nitric oxide suggesting a role for RBCs in hemostasis and thrombosis. Here we provide evidence for a significant contribution of RBCs to thrombus formation. Anemic mice showed enhanced occlusion times upon injury of the carotid artery. A small population of RBCs was located to platelet thrombi and enhanced platelet activation by a direct cell contact via the FasL-FasR (CD95) pathway known to induce apoptosis. Activation of platelets in the presence of RBCs led to platelet FasL exposure that activated FasR on RBCs responsible for externalization of phosphatidylserine (PS) on the RBC membrane. Inhibition or genetic deletion of either FasL or FasR resulted in reduced PS exposure of RBCs and platelets, decreased thrombin generation and reduced thrombus formation in vitro and protection against arterial thrombosis in vivo. Direct cell contacts of platelets and RBCs via FasL-FasR were shown after ligation of the inferior vena cava (IVC) and in surgical specimens of patients after thrombectomy. In a flow restriction model of the IVC, reduced thrombus formation was observed in FasL–/– mice. Taken together, our data reveal a significant contribution of RBCs to thrombosis by the FasL-FasR pathway.

Authors

Christoph Klatt, Irena Krüger, Saskia Zey, Kim-Jürgen Krott, Martina Spelleken, Nina Sarah Gowert, Alexander Oberhuber, Lena Pfaff, Wiebke Lückstädt, Kerstin Jurk, Martin Schaller, Hadi Al-Hasani, Jürgen Schrader, Steffen Massberg, Konstantin Stark, Hubert Schelzig, Malte Kelm, Margitta Elvers

ATR kinase inhibitor AZD6738 potentiates CD8⁺ T cell-dependent antitumor activity following radiation

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Abstract

DNA damaging chemotherapy and radiation therapy are integrated into the treatment paradigm of the majority of cancer patients. Recently, immunotherapy that targets the immunosuppressive interaction between Programmed Death 1 (PD-1) and its ligand PD-L1 has been approved for malignancies including non-small lung cancer (NSCLC), melanoma, and head and neck squamous cell carcinoma (HNSCC). ATR is a DNA damage signaling kinase activated at damaged replication forks and ATR kinase inhibitors potentiate the cytotoxicity of DNA damaging chemotherapies. We show here that the ATR kinase inhibitor AZD6738 combines with conformal radiation therapy to attenuate radiation-induced CD8+ T cell exhaustion and potentiate CD8+ T cell activity in mouse models of Kras-mutant cancer. Mechanistically, AZD6738 blocks radiation-induced PD-L1 upregulation on tumor cells and dramatically decreases the number of tumor-infiltrating T regulatory (Treg) cells. Remarkably, AZD6738 combines with conformal radiation therapy to generate immunologic memory in complete responder mice. Our work raises the exciting possibility that a single pharmacologic agent may enhance the cytotoxic effects of radiation while concurrently potentiating radiation-induced antitumor immune responses.

Authors

Frank P. Vendetti, Pooja Karukonda, David A. Clump, Troy Teo, Ronald Lalonde, Katriana Nugent, Matthew Ballew, Brian F. Kiesel, Jan H. Beumer, Saumendra N. Sarkar, Thomas P. Conrads, Mark J. O'Connor, Robert L. Ferris, Phuoc T. Tran, Greg M. Delgoffe, Christopher J. Bakkenist

Neuropilin-1 upregulation elicits adaptive resistance to oncogene-targeted therapies

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Abstract

Cancer cell dependence on activated oncogenes is targeted therapeutically, but acquired resistance is virtually unavoidable. Here we show that the treatment of addicted melanoma cells with BRAF-inhibitors, and of breast cancer cells with HER2-targeted drugs, led to an adaptive rise in Neuropilin-1 (NRP1) expression, which is crucial for the onset of acquired resistance to therapy. Moreover, NRP1 levels dictated the efficacy of MET oncogene-inhibitors in addicted stomach and lung carcinoma cells. Mechanistically, NRP1 induced a JNK-dependent signaling cascade leading to the upregulation of alternative effector kinases, EGFR or IGF1R, which in turn sustained cancer cell growth and mediated acquired resistance to BRAF, HER2, or MET inhibitors. Notably, the combination with NRP1-interfering molecules improved the efficacy of oncogene-targeted drugs, and prevented, or even reversed, the onset of resistance in cancer cells and tumor models. Our study provides the rationale for targeting the NRP1-dependent upregulation of tyrosine kinases, responsible for loss of responsiveness to oncogene-targeted therapies.

Authors

Sabrina Rizzolio, Gabriella Cagnoni, Chiara Battistini, Stefano Bonelli, Claudio Isella, Jo A. Van Ginderachter, René Bernards, Federica Di Nicolantonio, Silvia Giordano, Luca Tamagnone

High-accuracy determination of internal circadian time from a single blood sample

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Abstract

BACKGROUND. The circadian clock is a fundamental and pervasive biological program that coordinates 24-hour rhythms in physiology, metabolism and behaviour, and it is essential to health. Whereas time-of-day adapted therapy is increasingly reported to be highly successful, it needs to be personalized since internal circadian time is different for each individual. In addition, internal time is not a stable trait, but is influenced by many factors including genetic predisposition, age, gender, environmental light levels and season. An easy and convenient diagnostic tool is currently missing. METHODS. To establish a validated test, we followed a three-stage biomarker development strategy: (i) using circadian transcriptomics of blood monocytes from 12 individuals in a constant routine protocol combined with machine learning approaches, we identified biomarkers for internal time; (ii) these biomarkers were migrated to a clinically relevant gene expression-profiling platform (NanoString), and (iii) externally validated using an independent study with 28 early or late chronotypes. RESULTS. We developed a highly accurate and simple assay (BodyTime) to estimate the internal circadian time in humans from a single blood sample. Our assay needs only a small set of blood-based transcript biomarkers and is as accurate as the current gold standard dim light melatonin onset method at smaller monetary, time and sample number cost. CONCLUSION. The BodyTime assay provides a new diagnostic tool for personalization of healthcare according to the patient’s circadian clock. FUNDING. This study was supported by the Bundesministerium für Bildung und Forschung, Germany (FKZ: 13N13160 and 13N13162) and Intellux GmbH, Germany.

Authors

Nicole Wittenbrink, Bharath Ananthasubramaniam, Mirjam Münch, Barbara Koller, Bert Maier, Charlotte Weschke, Frederik Bes, Jan de Zeeuw, Claudia Nowozin, Amely Wahnschaffe, Sophia Wisniewski, Mandy Zaleska, Osnat Bartok, Reut Ashwal-Fluss, Hedwig Lammert, Hanspeter Herzel, Michael Hummel, Sebastian Kadener, Dieter Kunz, Achim Kramer

TET2 controls chemoresistant slow-cycling cancer cell survival and tumor recurrence

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Abstract

Dormant or slow-cycling tumour cells can form a residual chemoresistant reservoir responsible for relapse in patients, years after curative surgery and adjuvant therapy. We have adapted the pulse-chase expression of H2BeGFP for labelling and isolating slow-cycling cancer cells (SCCC). SCCC showed cancer-initiation potential and enhanced chemoresistance. Cells at this slow-cycling status presented a distinctive non-genetic and cell-autonomous gene expression profile shared across different tumour types. We identified TET2 epigenetic enzyme as key factor controlling SCCC numbers, survival and tumour recurrence. 5-Hydroxymethylcytosine (5hmC), generated by TET2 enzymatic activity, labelled SCCC genome in carcinomas and was a predictive biomarker of relapse and survival in cancer patients. We have shown the enhanced chemoresistance of SCCC, revealed 5hmC as a biomarker for their clinical identification, and TET2 as a potential drug-target for SCCC elimination that could extend patients’ survival.

Authors

Isabel Puig, Stephan P. Tenbaum, Irene Chicote, Oriol Arqués, Jordi Martínez-Quintanilla, Estefania Cuesta-Borrás, Lorena Ramírez, Pilar Gonzalo, Atenea Soto, Susana Aguilar, Cristina Eguizabal, Ginevra Caratù, Aleix Prat, Guillem Argilés, Stefania Landolfi, Oriol Casanovas, Violeta Serra, Alberto Villanueva, Alicia G. Arroyo, Luigi Terracciano, Paolo Nuciforo, Joan Seoane, Juan A. Recio, Ana Vivancos, Rodrigo Dienstmann, Josep Tabernero, Héctor G. Palmer

Th1/Th17 polarization persists following whole-cell pertussis vaccination despite repeated acellular boosters

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Abstract

In the mid-1990s, whole-cell (wP) pertussis vaccines were associated with local and systemic adverse events, which prompted their replacement with acellular (aP) vaccines in many high-income countries. In the past decade rates of pertussis disease have increased in children receiving only acellular pertussis vaccines. We compared the immune responses to acellular pertussis boosters in children who received their initial doses with either wP or aP vaccines using activation-induced marker (AIM) assays. Specifically, we examined pertussis-specific memory CD4+ T cell responses ex vivo, highlighting a Type 2/Th2 versus Type 1/Th1 and Th17 differential polarization as a function of childhood vaccination. Remarkably, after a contemporary aP booster, cells from donors originally primed with aP were 1) associated with increased IL-4, IL-5, IL-13, IL-9 and TGF-β and decreased IFNγ and IL-17 production; 2) defective in their ex vivo capacity to expand memory cells; and 3) less capable to proliferate in vitro. These differences appeared to be T cell-specific, since equivalent increases of antibody titers and plasmablasts after aP boost were seen in both groups. In conclusion, our data suggest that long lasting effects and differential polarization and proliferation exists between adults originally vaccinated with aP versus wP despite repeated acellular boosters.

Authors

Ricardo da Silva Antunes, Mariana Babor, Chelsea Carpenter, Natalie Khalil, Mario Cortese, Alexander J Mentzer, Grégory Seumois, Christopher D. Petro, Lisa A. Purcell, Pandurangan Vijayanand, Shane Crotty, Bali Pulendran, Bjorn Peters, Alessandro Sette

Expression of mutant Sftpc in murine alveolar epithelia drives spontaneous lung fibrosis

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Abstract

Epithelial cell dysfunction is postulated as an important component in the pathogenesis of Idiopathic Pulmonary Fibrosis (IPF). Mutations in the Surfactant Protein C [SP-C] gene [SFTPC], an alveolar type 2 (AT2) cell restricted protein, have been found in sporadic and familial IPF. To causally link these events, we developed a knock-in mouse model capable of regulated expression of an IPF-associated Isoleucine to Threonine substitution at codon 73 [I73T] in Sftpc (SP-CI73T). Tamoxifen treated SP-CI73T cohorts developed rapid increases in SftpcI73T mRNA and misprocessed proSP-CI73T protein accompanied by increased early mortality (days 7-14). This acute phase was marked by diffuse parenchymal lung injury, tissue infiltration by monocytes, polycellular alveolitis, and elevations in bronchoalveolar lavage and AT2 mRNA contents of select inflammatory cytokines. Resolution of alveolitis (2-4 weeks), commensurate with a rise in TGFB1, was followed by aberrant remodeling marked by collagen deposition, AT2 cell hyperplasia, a-SMA positive cells, and restrictive lung physiology. The translational relevance of the model was supported by detection of multiple IPF biomarkers previously reported in human cohorts. These data provide proof of principle that mutant SP-C expression in vivo causes spontaneous lung fibrosis strengthening the role of AT2 dysfunction as a key upstream driver of IPF pathogenesis.

Authors

Shin-Ichi Nureki, Yaniv Tomer, Alessandro Venosa, Jeremy Katzen, Scott J. Russo, Sarita Jamil, Matthew Barrett, Vivian Nguyen, Meghan Kopp, Surafel Mulugeta, Michael F. Beers

Itaconic acid mediates crosstalk between macrophage metabolism and peritoneal tumors

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Abstract

Control of cellular metabolism is critical for efficient cell function, although little is known about the interplay between cell subset-specific metabolites in situ, especially in the tumor setting. Here, we determine how a macrophage-specific metabolite, itaconic acid, can regulate tumor progression in the peritoneum. We show peritoneal tumors (B16 melanoma or ID8 ovarian carcinoma) elicited a fatty acid oxidation-mediated increase in oxidative phosphorylation (OXPHOS) and glycolysis in peritoneal tissue-resident macrophages (pResMφ). Unbiased metabolomics identified itaconic acid, the product of Irg1-mediated catabolism of mitochondrial cis-aconitate, among the most highly upregulated metabolites in pResMφ of tumor-bearing mice. Administration of lentivirally-encoded Irg1 shRNA significantly reduced peritoneal tumors. This resulted in reductions in OXPHOS and OXPHOS-driven production of reactive oxygen species (ROS) in pResMφ and ROS-mediated MAP kinase activation in tumor cells. Our findings demonstrate that tumors profoundly alter pResMφ metabolism, leading to the production of itaconic acid, which potentiates tumor growth. Monocytes isolated from ovarian carcinoma patient ascites fluid expressed significantly elevated levels of Irg1. Therefore, Irg1 in pResMφ represents a potential therapeutic target for peritoneal tumors.

Authors

Jonathan M. Weiss, Luke C. Davies, Megan Karwan, Lilia Ileva, Michelle K. Ozaki, Robert Y.S. Cheng, Lisa A. Ridnour, Christina M. Annunziata, David A. Wink, Daniel W. McVicar

Oncogenic TRK fusions are amenable to inhibition in hematologic malignancies

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Abstract

Rearrangements involving the neurotrophic receptor kinase genes (NTRK1, NTRK2, and NTRK3; hereafter referred to as TRK) produce oncogenic fusions in a wide variety of cancers in adults and children. Although TRK fusions occur in <1% of all solid tumors, inhibition of TRK results in profound therapeutic responses resulting in breakthrough FDA-approval of the TRK inhibitor larotrectinib for adult and pediatric solid tumor patients regardless of histology. In contrast to solid tumors, the frequency of TRK fusions and clinical effects of targeting TRK in hematologic malignancies is unknown. Here, through an evaluation for TRK fusions across > 7,000 patients with hematologic malignancies, we identified TRK fusions in acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), histiocytosis, multiple myeloma and dendritic cell neoplasms. Although TRK fusions occurred in only 0.1% of patients (8 out of 7,311 patients), they conferred responsiveness to TRK inhibition in vitro and in vivo in a patient-derived xenograft and a corresponding AML patient with ETV6-NTRK2 fusion. These data identify that despite their individual rarity, collectively TRK fusions are present in a wide variety of hematologic malignancies and predict clinically significant therapeutic responses to TRK inhibition.

Authors

Justin Taylor, Dean Pavlick, Akihide Yoshimi, Christina Marcelus, Stephen S. Chung, Jaclyn F. Hechtman, Ryma Benayed, Emiliano Cocco, Benjamin H. Durham, Lillian Bitner, Daichi Inoue, Young Rock Chung, Kerry Mullaney, Justin M. Watts, Eli L. Diamond, Lee A. Albacker, Tariq I. Mughal, Kevin Ebata, Brian B. Tuch, Nora Ku, Maurizio Scaltriti, Mikhail Roshal, Maria Arcila, Siraj Ali, David M. Hyman, Jae H. Park, Omar Abdel-Wahab

HECTD3 mediates TRAF3 polyubiquitination and type I interferon induction during bacterial infection

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Abstract

Lysine-63 (K63)–linked polyubiquitination of TRAF3 coordinates the engagement of pattern recognition receptors to recruited adaptor proteins and downstream activator TBK1 in pathways that induce type I interferon (IFN). Whether auto-ubiquitination or other E3 ligases mediate K63-linked TRAF3 polyubiquitination remains unclear. We demonstrated that mice deficient in E3 ligase gene Hectd3 remarkably increased host defense against infection by intracellular bacteria F. novicida, Mycobacterium, and Listeria by limiting bacterial dissemination. In the absence of HECTD3, type I IFN response was impaired during bacterial infection both in vivo and in vitro. HECTD3 regulated type I IFN production by mediating K63-linked polyubiquitination of TRAF3 at residue K138. The catalytic domain of HECTD3 regulated TRAF3 K63 polyubiquitination, which enabled TRAF3–TBK1 complex formation. Our study offers novel insights into mechanisms of TRAF3 modulation and provides potential therapeutic targets against infections by intracellular bacteria and inflammatory diseases.

Authors

Fubing Li, Yang Li, Huichun Liang, Tao Xu, Yanjie Kong, Maobo Huang, Ji Xiao, Xi Chen, Houjun Xia, Yingying Wu, Zhongmei Zhou, Xiaomin Guo, Chunmiao Hu, Chuanyu Yang, Xu Cheng, Ceshi Chen, Xiaopeng Qi

Autophagy orchestrates the regulatory program of tumor-associated myeloid-derived suppressor cells

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Abstract

Myeloid-derived suppressor cells (MDSCs) densely accumulate into tumors and potently suppress anti-tumor immune responses promoting tumor development. Targeting MDSCs in tumor immunotherapy has been hampered by lack of understanding of the molecular pathways that govern MDSC differentiation and function. Herein, we identify autophagy as a crucial pathway for MDSC-mediated suppression of anti-tumor immunity. Specifically, MDSCs in melanoma patients and mouse melanoma exhibited increased levels of functional autophagy. Ablation of autophagy in myeloid cells, significantly delayed tumor growth and endowed anti-tumor immune responses. Notably, tumor-infiltrating autophagy-deficient monocytic MDSCs (M-MDSCs) demonstrated impaired suppressive activity in vitro and in vivo, while transcriptome analysis revealed significant differences in genes related to lysosomal function. Accordingly, autophagy-deficient M-MDSCs exhibited impaired lysosomal degradation thereby enhancing surface expression of MHC class II molecules, resulting in efficient activation of tumor-specific CD4+ T cells. Finally, targeting of the membrane-associated RING-CH1 (MARCH1) E3 ubiquitin ligase, that mediates the lysosomal degradation of MHC II, in M-MDSCs, attenuated their suppressive function, and resulted in significantly decreased tumor volume followed by development of a robust anti-tumor immunity. Collectively, these findings depict autophagy as a novel molecular target of MDSC-mediated suppression of anti-tumor immunity.

Authors

Themis Alissafi, Aikaterini Hatzioannou, Konstantinos Mintzas, Roza Maria Barouni, Aggelos Banos, Sundary Sormendi, Alexandros Polyzos, Maria Xilouri, Ben Wielockx, Helen Gogas, Panayotis Verginis

Modulation of EZH2 expression in T cells improves efficacy of anti–CTLA-4 therapy

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Abstract

EZH2-mediated epigenetic regulation of T cell differentiation and regulatory T cell function has been described previously; however, the role of EZH2 in T cell–mediated anti-tumor immunity, especially in the context of immune checkpoint therapy, is not understood. Here, we showed that genetic depletion of EZH2 in regulatory T cells (FoxP3creEZH2fl/fl mice) leads to robust anti-tumor immunity. In addition, pharmacological inhibition of EZH2 in human T cells using CPI-1205 elicited phenotypic and functional alterations of the regulatory T cells and enhanced cytotoxic activity of effector T cells. We observed that ipilimumab (anti–CTLA-4) increased EZH2 expression in peripheral T cells from treated patients. We hypothesized that inhibition of EZH2 expression in T cells would increase the effectiveness of anti–CTLA-4 therapy, which we tested in murine models. Collectively, our data demonstrated that modulating EZH2 expression in T cells can improve anti-tumor responses elicited by anti–CTLA-4 therapy, which provides a strong rationale for a combination trial of CPI-1205 plus ipilimumab.

Authors

Sangeeta Goswami, Irina Apostolou, Jan Zhang, Jill Skepner, Swetha Anandhan, Xuejun Zhang, Liangwen Xiong, Patrick Trojer, Ana Aparicio, Sumit K. Subudhi, James P. Allison, Hao Zhao, Padmanee Sharma

Galactose protects against cell damage in mouse models of acute pancreatitis

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Abstract

Acute pancreatitis (AP), a human disease in which the pancreas digests itself, has substantial mortality with no specific therapy. The major causes of AP are alcohol abuse and gallstone complications, but it also occurs as an important side effect of the standard Asparaginase-based therapy for childhood acute lymphoblastic leukaemia. Previous investigations into the mechanisms underlying pancreatic acinar cell death induced by alcohol metabolites, bile acids or Asparaginase indicated that loss of intracellular ATP generation is a significant factor. In isolated mouse pancreatic acinar cells or cell clusters, we now report that removal of extracellular glucose had little effect on this ATP loss, suggesting that glucose metabolism was severely inhibited under these conditions. Surprisingly, we show that replacing glucose with galactose prevented or markedly reduced the loss of ATP and any subsequent necrosis. Addition of pyruvate had a similar protective effect. We also studied the effect of galactose in vivo in mouse models of AP induced either by a combination of fatty acids and ethanol or Asparaginase. In both cases, galactose markedly reduced acinar necrosis and inflammation. Based on these data we suggest that galactose feeding may be used to protect against AP.

Authors

Shuang Peng, Julia V. Gerasimenko, Tetyana M. Tsugorka, Oleksiy Gryshchenko, Sujith Samarasinghe, Ole H. Petersen, Oleg V. Gerasimenko

Ca²⁺-binding protein NECAB2 facilitates inflammatory pain hypersensitivity

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Abstract

Painful signals are transmitted by mutisynaptic glutamatergic pathways. Their first synapse between primary nociceptors and excitatory spinal interneurons gates sensory load. Glutamate release herein is orchestrated by Ca2+ sensor proteins with neuronal calcium-binding protein 2 (NECAB2) being particularly abundant. However, neither the importance of NECAB2+ neuronal contingents in dorsal root ganglia (DRG) and spinal cord nor function-determination by NECAB2 has been defined. A combination of histochemistry and single-cell RNA-seq showed NECAB2 in small/medium-sized C- and Aδ D-hair low threshold mechanoreceptors in DRG, as well as in protein kinase γ-positive excitatory spinal interneurons. NECAB2 was downregulated by peripheral nerve injury, offering the hypothesis that NECAB2 loss-of-funtion could limit pain sensation. Indeed, Necab2–/– mice reached a pain-free state significantly faster after peripheral inflammation than wild-type littermates. Genetic access to transiently-activated neurons revealed that a mediodorsal cohort of NECAB2+ neurons mediates inflammatory pain in mouse spinal dorsal horn. Here, besides dampening excitatory transmission in spinal interneurons, NECAB2 limited pronociceptive brain-derived neurotrophic factor release from sensory afferents. Hox8b-dependent reinstatement of NECAB2 expression in Necab2–/– mice then demonstrated that spinal/DRG NECAB2 alone could control inflammation-induced sensory hyperensitivity. Overall, we identify NECAB2 as a critical component of pro-nociceptive pain signaling whose inactivation offers substantial pain relief.

Authors

Ming-Dong Zhang, Jie Su, Csaba Adori, Valentina Cinquina, Katarzyna Malenczyk, Fatima Girach, Changgeng Peng, Patrik Ernfors, Peter Löw, Lotta Borgius, Ole Kiehn, Masahiko Watanabe, Mathias Uhlén, Nicholas Mitsios, Jan Mulder, Tibor Harkany, Tomas Hökfelt

Purinergic P2X4 receptors and mitochondrial ATP production regulate T cell migration

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Abstract

T cells must migrate in order to encounter antigen-presenting cells (APCs) and to execute their varied functions in immune defense and inflammation. ATP release and autocrine signaling through purinergic receptors contribute to T cell activation at the immune synapse that T cells form with APCs. Here, we show that T cells also require ATP release and purinergic signaling for their migration to APCs. We found that the chemokine SDF-1α triggered mitochondrial ATP production, rapid bursts of ATP release, and increased migration of primary human CD4+ T cells. This process depended on pannexin-1 ATP release channels and autocrine stimulation of P2X4 receptors. SDF-1α stimulation caused localized accumulation of mitochondria with P2X4 receptors near the front of cells, resulting in a feed-forward signaling mechanism that promotes cellular Ca2+ influx and sustains mitochondrial ATP synthesis at levels needed for pseudopod protrusion, T cell polarization, and cell migration. Inhibition of P2X4 receptors blocked the activation and migration of T cells in vitro. In a mouse lung transplant model, P2X4 receptor antagonist treatment prevented the recruitment of T cells into allograft tissue and the rejection of lung transplants. Our findings suggest that P2X4 receptors are therapeutic targets for immunomodulation in transplantation and inflammatory diseases.

Authors

Carola Ledderose, Kaifeng Liu, Yutaka Kondo, Christian J. Slubowski, Thomas Dertnig, Sara Denicoló, Mona Arbab, Johannes Hubner, Kirstin Konrad, Mahtab Fakhari, James A. Lederer, Simon C. Robson, Gary A. Visner, Wolfgang G. Junger

PRDM16 isoforms differentially regulate normal and leukemic hematopoiesis and inflammatory gene signature

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Abstract

PRDM16 is a transcriptional co-regulator involved in translocations in acute myeloblastic leukemia (AML), myelodysplastic syndromes and T acute lymphoblastic leukemia that is highly expressed in and required for the maintenance of hematopoietic stem cells (HSCs), and can be aberrantly expressed in AML. Prdm16 is expressed as full-length (fPrdm16) and short (sPrdm16) isoforms, the latter lacking the N-terminal PR-domain. The role of both isoforms in normal and malignant hematopoiesis is unclear. We show here that fPrdm16 was critical for HSC maintenance, induced multiple genes involved in GTPase signaling and repressed inflammation, while sPrdm16 supported B-cell development biased towards marginal zone B-cells and induced an inflammatory signature. In a mouse model of human MLL-AF9 leukemia fPrdm16 extended latency, while sPrdm16 shortened latency and induced a strong inflammatory signature, including several cytokines and chemokines that are associated with myelodysplasia and with a worse prognosis in human AML. Finally, in human NPM1-mutant and in MLL-translocated AML high expression of PRDM16, which negatively impacts outcome, was associated with inflammatory gene expression, thus corroborating the mouse data. Our observations demonstrate distinct roles for Prdm16 isoforms in normal HSCs and AML, and identify sPrdm16 as one of the drivers of prognostically adverse inflammation in leukemia.

Authors

David J. Corrigan, Larry L. Luchsinger, Mariana Justino de Almeida, Linda J. Williams, Alexandros Strikoudis, Hans-Willem Snoeck

Hijacking a key chromatin modulator creates epigenetic vulnerability for Myc-driven cancer

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Abstract

While the genomic binding of MYC protein correlates with active epigenetic marks on chromatin, it remains largely unclear how major epigenetic mechanisms functionally impact the tumorigenic potential of MYC. Here we showed that compared to the catalytic subunits, the core subunits, including DPY30, of the major H3K4 methyltransferase complexes were frequently amplified in human cancers, and selectively upregulated in Burkitt lymphoma. We showed that DPY30 promoted expression of endogenous MYC, and was also functionally important for efficient binding of MYC to its genomic targets by regulating chromatin accessibility. Dpy30 heterozygosity did not affect normal animal physiology including life span, but significantly suppressed Myc-driven lymphomagenesis, as cells failed to combat oncogene-triggered apoptosis due to insufficient epigenetic modulation and expression of a subset of anti-apoptotic genes. Dpy30 reduction also greatly impeded MYC-dependent cellular transformation without affecting normal cell growth. These results suggest that MYC hijacks a major epigenetic pathway — H3K4 methylation — to facilitate its molecular activity in target binding and to coordinate its oncogenic program for efficient tumorigenesis, meanwhile creating “epigenetic vulnerability.” DPY30 and the H3K4 methylation pathway are thus potential epigenetic targets for treating certain MYC-driven cancers.

Authors

Zhenhua Yang, Kushani Shah, Theodore Busby, Keith Giles, Alireza Khodadadi-Jamayran, Wei Li, Hao Jiang