Erythrocyte-derived microvesicles induce arterial spasms in JAK2V617F myeloproliferative neoplasm

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Abstract

Arterial cardiovascular events are the leading cause of death in patients with JAK2V617F myeloproliferative neoplasms (MPN). However, their mechanisms are poorly understood. The high prevalence of myocardial infarction without significant coronary stenosis or atherosclerosis in patients with MPN suggests that vascular function is altered. Consequences of JAK2V617F mutation on vascular reactivity are unknown. We observe here increased responses to vasoconstrictors in arteries from Jak2V617F mice, resulting from disturbed endothelial nitric oxide pathway and increased endothelial oxidative stress. This response was reproduced in wild-type mice by circulating microvesicles isolated from patients carrying JAK2V617F and by erythrocyte-derived microvesicles from transgenic mice. Microvesicles of other cellular origins had no effect. This effect was observed ex vivo on isolated aortas, but also in vivo on femoral arteries. Proteomic analysis of microvesicles derived from JAK2V617F erythrocytes identified increased expression of myeloperoxidase as the likely mechanism accounting for microvesicles effect. Myeloperoxidase inhibition in microvesicles derived from JAK2V617F erythrocytes supressed their effect on oxidative stress. Antioxidants, such as simvastatin and N-acetyl-cysteine, improved arterial dysfunction in Jak2V617F mice. In conclusion, JAK2V617F MPN are characterized by exacerbated vasoconstrictor responses resulting from increased endothelial oxidative stress caused by circulating erythrocyte-derived microvesicles. Simvastatin appears as promising therapeutic strategy in this setting.

Authors

Johanne Poisson, Marion Tanguy, Hortense Davy, Fatoumata Camara, Marie-Belle El Mdawar, Marouane Kheloufi, Tracy Dagher, Cécile Devue, Juliette Lasselin, Aurelie Plessier, Salma Merchant, Olivier Blanc-Brude, Michele Souyri, Nathalie Mougenot, Florent Dingli, Damarys Loew, Stephane N. Hatem, Chloe James, Jean-Luc Villeval, Chantal M. Boulanger, Pierre-Emmanuel Rautou

Hepatic CEACAM1 expression indicates donor liver quality and prevents early transplantation injury

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Abstract

Although CEACAM1 (CC1) glycoprotein resides at the interface of immune liver injury and metabolic homeostasis, its role in orthotopic liver transplantation (OLT) remains elusive. We aimed to determine whether/how CEACAM1 signaling may affect hepatic ischemia-reperfusion injury (IRI) and OLT outcomes. In the mouse, donor liver CC1 null mutation augmented IRI-OLT (CC1-KO>WT) by enhancing ROS expression and HMGB1 translocation during cold storage, data supported by in vitro studies where hepatic flush from CC1-deficient livers enhanced macrophage activation in BMDM cultures. Although hepatic CC1 deficiency augmented cold stress-triggered ASK1/p-p38 upregulation, adjunctive ASK1 inhibition alleviated IRI/improved OLT survival by suppressing p-p38 upregulation, ROS induction/HMGB1 translocation (CC1-KO>WT); while ASK1 silencing (siRNA) promoted cytoprotection in cold-stressed and damage-prone CC1-deficient hepatocyte cultures. Consistent with mouse data, CEACAM1 expression in sixty human donor liver biopsies correlated negatively with activation of ASK1/p-p38 axis; while low-CC1 levels associated with increased ROS/HMGB1 translocation, enhanced innate/adaptive immune responses and inferior early OLT function. Notably, reduced donor liver CEACAM1 expression was identified as one of independent predictors for EAD in human OLT patients. Thus, as a checkpoint regulator of IR-stress/sterile inflammation, CEACAM1 may be considered as a denominator of donor hepatic tissue quality, and a target for therapeutic modulation in OLT recipients.

Authors

Kojiro Nakamura, Shoichi Kageyama, Fady M. Kaldas, Hirofumi Hirao, Takahiro Ito, Kentaro Kadono, Kenneth J. Dery, Hidenobu Kojima, David W. Gjertson, Rebecca A. Sosa, Maciej Kujawski, Ronald W. Busuttil, Elaine F. Reed, Jerzy W. Kupiec-Weglinski

Exosomes mediate sensory hair cell protection in the inner ear

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Abstract

Hair cells are the mechanosensory receptors of the inner ear, responsible for hearing and balance. Hair cell death and consequent hearing loss are common results of treatment with ototoxic drugs, including the widely-used aminoglycoside antibiotics. Induction of heat shock proteins (HSPs) confers protection against aminoglycoside-induced hair cell death via paracrine signaling that requires extracellular HSP70 (Heat Shock 70 kDa Protein). We investigated the mechanisms underlying this non-cell-autonomous protective signaling in the inner ear. In response to heat stress, inner ear tissue releases exosomes that carry HSP70 in addition to canonical exosome markers and other proteins. Isolated exosomes from heat-shocked utricles were sufficient to improve survival of hair cells exposed to the aminoglycoside antibiotic neomycin, while inhibition or depletion of exosomes from the extracellular environment abolished the protective effect of heat shock. Hair-cell specific expression of the known HSP70 receptor, Toll-like receptor 4 (TLR4), was required for the protective effect of exosomes, and exosomal HSP70 interacted with TLR4 on hair cells. Our results indicate that exosomes are a previously undescribed mechanism of intercellular communication in the inner ear that can mediate non-autonomous hair cell survival. Exosomes may represent a novel class of nano-carriers for delivery of therapeutics against hearing loss.

Authors

Andrew M. Breglio, Lindsey A. May, Melanie Barzik, Nora C. Welsh, Shimon P. Francis, Tucker Q. Costain, Lizhen Wang, D. Eric Anderson, Ronald S. Petralia, Ya-Xian Wang, Thomas B. Friedman, Matthew J.A. Wood, Lisa L. Cunningham

BCL-2 antagonism sensitizes cytotoxic t cell-resistant hiv reservoirs to elimination ex vivo

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Abstract

Curing HIV infection will require the elimination of a reservoir of infected CD4+ T-cells that persists despite HIV-specific cytotoxic T-cell (CTL) responses. While viral latency is a critical factor in this persistence, recent evidence also suggests a role for intrinsic resistance of reservoir-harboring cells to CTL killing. This resistance may have contributed to negative outcomes of clinical trials, where pharmacologic latency reversal has thus far failed to drive reductions in HIV reservoirs. Through transcriptional profiling, we herein identified over-expression of the pro-survival factor BCL-2 as a distinguishing feature of CD4+ T-cells that survived CTL killing. We show that the inducible HIV reservoir was disproportionately present in BCL-2hi subsets, in ex vivo CD4+ T-cells. Treatment with the BCL-2 antagonist ‘ABT-199’ alone was not sufficient to drive reductions in ex vivo viral reservoirs, when tested either alone or with a latency reversing agent (LRA). However, the triple combination of strong LRAs, HIV-specific T-cells, and a BCL-2 antagonist uniquely enabled the depletion of ex vivo viral reservoirs. Our results provide rationale for novel therapeutic approaches targeting HIV cure and, more generally, suggest consideration of BCL-2 antagonism as a means of enhancing CTL immunotherapy in other settings, such as cancer.

Authors

Yanqin Ren, Szu-Han Huang, Shabnum Patel, Winiffer D. Conce Alberto, Dean Magat, Dughan J. Ahimovic, Amanda B. Macedo, Ryan Durga, Dora Chan, Elizabeth Zale, Talia M. Mota, Ronald Truong, Thomas Rohwetter, Chase D. McCann, Colin M. Kovacs, Erika Benko, Avery Wimpelberg, Christopher M. Cannon, W. David Hardy, Alberto Bosque, Catherine M. Bollard, R. Brad Jones

Epigenetic driver mutations in ARID1A shape cancer immune phenotype and immunotherapy

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Abstract

Whether mutations in cancer driver genes directly affect cancer immune phenotype and T cell immunity remains a standing question. ARID1A is a core member of the polymorphic BAF chromatin remodeling complex. ARID1A mutations occur in human cancers and drive cancer development. Here, we studied the molecular, cellular, and clinical impact of ARID1A aberrations on cancer immunity. We demonstrated that ARID1A aberrations resulted in limited chromatin accessibility to interferon (IFN) responsive genes, caused impaired IFN-gene expression, anemic T cell tumor infiltration, poor tumor immunity, and shortened host survival in many human cancer histologies as well as in murine cancer models. Impaired IFN signaling was associated with poor immunotherapy response. Mechanistically, ARID1A interacted with EZH2 via its carboxyl terminal and antagonized EZH2-mediated IFN responsiveness. Thus, the interaction between ARID1A and EZH2 defines cancer IFN-responsiveness and immune evasion. Our work indicates that cancer epigenetic driver mutations can shape cancer immune phenotype and immunotherapy.

Authors

Jing Li, Weichao Wang, Yajia Zhang, Marcin Cieślik, Jipeng Guo, Mengyao Tan, Michael D. Green, Weimin Wang, Heng Lin, Wei Li, Shuang Wei, Jiajia Zhou, Gaopeng Li, Xiaojun Jing, Linda Vatan, Lili Zhao, Benjamin Bitler, Rugang Zhang, Kathleen R. Cho, Yali Dou, Ilona Kryczek, Timothy A. Chan, David Huntsman, Arul M. Chinnaiyan, Weiping Zou

The lymph node stromal laminin alpha 5 shapes alloimmunity

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Abstract

Lymph node stromal cells (LNSC) regulate immunity through constructing lymphocyte niches. LNSC produced Laminin α5 (Lama5) regulates CD4 T cells but the underlying mechanisms of its functions are poorly understood. Here we showed depleting Lama5 in LNSC resulted in decreased Lama5 protein in the LN cortical ridge (CR) and around high endothelial venules (HEV). Lama5 depletion affected LN structure with increased HEV, upregulated chemokines and cell adhesion molecules, and led to greater numbers of Treg in T cell zone. Mouse and human T cell transendothelial migration and T cell entry to LN were suppressed by Lama5 through the receptors a6 integrin and α-dystroglycan. During immune responses and allograft transplantation, depleting Lama5 promoted antigen specific CD4 T cell entry to the CR through HEV, suppressed T cell activation and altered T cell differentiation to suppressive regulatory phenotypes. Enhanced allograft acceptance resulted from depleting Lama5 or blockade of T cell Lama5 receptors. Lama5 and Lama4:Lama5 ratios in allografts were associated with the rejection severity. Overall, our results demonstrated that stromal Lama5 regulated immune responses through altering LN structures and T cell behaviors. The study delineated a stromal Lama5-T cell receptors axis that can be targeted for immune tolerance modulation.

Authors

Lushen Li, Marina W. Shirkey, Tianshu Zhang, Yanbao Xiong, Wenji Piao, Vikas Saxena, Christina Paluskievicz, Young S. Lee, Nicholas Toney, Benjamin M. Cerel, Qinshan Li, Thomas Simon, Kyle D. Smith, Keli L. Hippen, Bruce R. Blazar, Reza Abdi, Jonathan S. Bromberg

Plasmacytoid dendritic cells sense HIV replication before detectable viremia following treatment interruption

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Abstract

Plasmacytoid dendritic cells (pDCs) are robust producers of interferon α (IFNα) and one of the first immune cells to respond to simian immunodeficiency virus infection. To elucidate responses to early HIV-1 replication, we studied blood pDCs in 29 HIV-infected participants who initiated antiretroviral therapy during acute infection and underwent analytic treatment interruption (ATI). An increased frequency of partially activated pDCs was observed in the blood prior to detection of HIV RNA. Concurrent with peak pDC frequency, there was a transient decline in the ability of pDCs to produce IFNα in vitro, which correlated with decreased interferon regulatory factory 7 (IRF7) and NF-kB phosphorylation. Levels of phosphorylated IRF7 and NF-kB inversely correlated with plasma IFNα2 levels, implying that pDCs were refractory to in vitro stimulation after IFNα production in vivo. After ATI, decreased expression of IFN genes in pDCs inversely correlated with time to viral detection, suggesting that pDC IFN loss is part of an effective early immune response. These data, from a limited cohort, provide a critical first step in understanding the earliest immune response to HIV-1 and suggest that changes in blood pDC frequency and function can be used as an indicator of viral replication before detectable plasma viremia.

Authors

Julie L. Mitchell, Hiroshi Takata, Roshell Muir, Donn J. Colby, Eugene Kroon, Trevor A. Crowell, Carlo Sacdalan, Suteeraporn Pinyakorn, Suwanna Pattamaswin, Khunthalee Benjapornpong, Rapee Trichavaroj, Randall L. Tressler, Lawrence Fox, Victoria R. Polonis, Diane L. Bolton, Frank Maldarelli, Sharon R. Lewin, Elias K. Haddad, Praphan Phanuphak, Merlin L. Robb, Nelson L. Michael, Mark de Souza, Nittaya Phanuphak, Jintanat Ananworanich, Lydie Trautmann

A tumor-intrinsic PD-L1-NLRP3 inflammasome signaling pathway drives resistance to anti-PD-1 immunotherapy

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Abstract

An in-depth understanding of immune escape mechanisms in cancer are likely to lead to innovative advances in immunotherapeutic strategies. However, much remains unknown regarding these mechanisms and how they impact immunotherapy resistance. Using several pre-clinical tumor models as well as clinical specimens, we report a newly identified mechanism whereby CD8+ T cell activation in response to PD-1 blockade induced a PD-L1-NLRP3 inflammasome signaling cascade that ultimately led to the recruitment of granulocytic myeloid-derived suppressor cells (PMN-MDSCs) into tumor tissues, thereby dampening the resulting anti-tumor immune response. The genetic and pharmacologic inhibition of NLRP3 suppressed PMN-MDSC tumor infiltration and significantly augmented the efficacy of anti-PD-1 antibody immunotherapy. This pathway therefore represents a tumor-intrinsic adaptive resistance mechanism to anti-PD-1 checkpoint inhibitor immunotherapy and is a promising target for future translational research.

Authors

Balamayooran Theivanthiran, Kathy S. Evans, Nicholas C. DeVito, Michael P. Plebanek, Michael Sturdivant, Lucas P. Wachsmuth, April K.S. Salama, Yubin Kang, David Hsu, Justin M. Balko, Douglas B. Johnson, Mark Starr, Andrew B. Nixon, Alisha Holtzhausen, Brent A. Hanks

Molecular cross-talk between Y5-receptor and neuropeptide Y drives liver cancer

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Abstract

Hepatocellular carcinoma (HCC) is clearly age-related and represents one of the deadliest cancer types worldwide. Due to globally increasing risk factors including metabolic disorders, the incidence rates of HCC are still rising. However, the molecular hallmarks of HCC remain poorly understood. Neuropeptide Y (NPY) and NPY-receptors represent a highly conserved, stress-activated system which is involved in diverse cancer-related hallmarks including aging and metabolic alterations, but its impact on liver cancer had been unclear. Here, we observed increased NPY5-receptor (Y5R) expression in HCC which correlated with tumor growth and survival. Furthermore, we found that its ligand NPY was secreted by peri-tumorous hepatocytes. Hepatocyte-derived NPY promoted HCC progression by Y5R-activation. Transforming growth factor beta 1 (TGFβ1) was identified as a regulator of NPY in hepatocytes and induced Y5R in invasive cancer cells. Moreover, NPY-conversion by dipeptidylpeptidase 4 (DPP4) augmented Y5R-activation and function in liver cancer. The TGFβ-NPY-Y5R-axis and DPP4 represent attractive therapeutic targets for controlling liver cancer progression.

Authors

Peter Dietrich, Laura Wormser, Valerie Fritz, Tatjana Seitz, Monica De Maria, Alexandra Schambony, Andreas E. Kremer, Claudia Günther, Timo Itzel, Wolfgang E. Thasler, Andreas Teufel, Jonel Trebicka, Arndt Hartmann, Markus F. Neurath, Stephan von Hörsten, Anja Bosserhoff, Claus Hellerbrand

Dysfunctional polycomb transcriptional repression contributes to Lamin A/C dependent muscular dystrophy

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Abstract

Lamin A is a component of the inner nuclear membrane that, together with epigenetic factors, organizes the genome in higher order structures required for transcriptional control. Mutations in the Lamin A/C gene cause several diseases, belonging to the class of laminopathies, including muscular dystrophies. Nevertheless, molecular mechanisms involved in the pathogenesis of Lamin A-dependent dystrophies are still largely unknown. Polycomb group of proteins (PcG) are epigenetic repressors and Lamin A interactors, primarily involved in the maintenance of cell identity. Using a murine model of Emery-Dreifuss Muscular Dystrophy (EDMD), we showed here that Lamin A loss deregulated PcG positioning in muscle satellite stem cells leading to de-repression of non-muscle specific genes and p16INK4a, a senescence driver encoded in the Cdkn2a locus. This aberrant transcriptional programme caused impairment in self-renewal, loss of cell identity and premature exhaustion of quiescent satellite cell pool. Genetic ablation of Cdkn2a locus restored muscle stem cell properties in Lamin A/C null dystrophic mice. Our findings established a direct link between Lamin A and PcG epigenetic silencing and indicated that Lamin A-dependent muscular dystrophy can be ascribed to intrinsic epigenetic dysfunctions of muscle stem cells.

Authors

Andrea Bianchi, Chiara Mozzetta, Gloria Pegoli, Federica Lucini, Sara Valsoni, Valentina Rosti, Cristiano Petrini, Alice Cortesi, Francesco Gregoretti, Laura Antonelli, Gennaro Oliva, Marco De Bardi, Roberto Rizzi, Beatrice Bodega, Diego Pasini, Francesco Ferrari, Claudia Bearzi, Chiara Lanzuolo