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Neutralizing antibody VRC01 failed to select for HIV-1 mutations upon viral rebound

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Abstract

Infusion of the broadly neutralizing antibody VRC01 has been evaluated in HIV-1 chronically infected individuals. Here we studied how VRC01 infusions impacted viral rebound after cessation of antiretroviral therapy (ART) in 18 acutely-treated and durably-suppressed individuals. Viral rebound occurred in all individuals, yet VRC01 infusions modestly delayed rebound and participants who showed a faster decay of VRC01 in serum rebounded more rapidly (Rho=0.60, p=0.03). Participants with strains most sensitive to VRC01 or with VRC01 epitope motifs similar to known VRC01-susceptible strains rebounded later (Rho=-0.70, p<0.03). Upon rebound, HIV-1 sequences were indistinguishable from those sampled at diagnosis. Across the cohort, participant derived Env showed different sensitivity to VRC01 neutralization (including two resistant viruses), yet neutralization sensitivity was similar at diagnosis and post-rebound, indicating the lack of selection for VRC01-resistance during treatment interruption.Our results showed that viremia rebounded despite the absence of HIV-1 adaptation to VRC01 and an average VRC01 trough of 221µg/mL. While VRC01 levels were insufficient to prevent a resurgent infection, knowledge that they did not mediate Env mutations in acute-like viruses is relevant for antibody-based strategies in acute infection.

Authors

Evan M. Cale, Hongjun Bai, Meera Bose, Michael A. Messina, Donn Colby, Eric Sanders-Buell, Bethany L. Dearlove, Yifan Li, Emily Engeman, Daniel Silas, Anne Marie O’Sullivan, Brendan Mann, Suteeraporn Pinyakorn, Jintana Intasan, Khunthalee Benjapornpong, Carlo Sacdalan, Eugene Kroon, Nittaya Phanuphak, Robert Gramzinski, Sandhya Vasan, Merlin L. Robb, Nelson L. Michael, Rebecca M. Lynch, Robert Bailer, Amélie Pagliuzza, Nicolas Chomont, Amarendra Pegu, Nicole A. Doria-Rose, Lydie Trautmann, Trevor A. Crowell, John Mascola, Jintanat Ananworanich, Sodsai Tovanabutra, Morgane Rolland

Diminished hepatic IFN response following HCV clearance triggers HBV reactivation in coinfection

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Abstract

In patients with HBV and HCV coinfection, HBV reactivation leading to severe hepatitis has been reported with the use of direct-acting antivirals (DAAs) to treat HCV infection. Here we study the molecular mechanisms behind this viral interaction. In coinfected cell culture and humanized mice, HBV replication was suppressed by HCV coinfection. In vitro, HBV suppression was attenuated when interferon signaling was blocked. In vivo, HBV viremia, after initial suppression by HCV super-infection, rebounded following HCV clearance by DAA treatment that was accompanied by a reduced hepatic interferon response. Using blood samples of coinfected patients, interferon-stimulated gene products including C-X-C motif chemokine 10 (CXCL10) and C-C motif chemokine ligand 5 (CCL5), and alanine aminotransferase (ALT) were identified to have predictive value for HBV reactivation after HCV clearance. Taken together, our data suggest that HBV reactivation is a result of diminished hepatic interferon response following HCV clearance and identifies serologic markers that can predict HBV reactivation in DAA-treated HBV-HCV coinfected persons.

Authors

Xiaoming Cheng, Takuro Uchida, Yuchen Xia, Regina Umarova, Chun-Jen Liu, Pei-Jer Chen, Anuj Gaggar, Vithika Suri, Marcus Maximilian Mücke, Johannes Vermehren, Stefan Zeuzem, Yuji Teraoka, Mitsutaka Osawa, Hiroshi Aikata, Keiji Tsuji, Nami Mori, Shuhei Hige, Yoshiyasu Karino, Michio Imamura, Kazuaki Chayama, T. Jake Liang

PIK3Cδ expression by fibroblasts promotes triple-negative breast cancer progression

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Abstract

As there is growing evidence for the tumor microenvironment’s (TME) role in tumorigenesis, we investigated the role of fibroblast-expressed kinases in triple negative breast cancer (TNBC). Using a high-throughput kinome screen combined with 3D invasion assays, we identified fibroblast-expressed PIK3Cδ (f-PIK3Cδ) as a key regulator of progression. Although PIK3Cδ was expressed in primary fibroblasts derived from TNBC patients, it was undetectable in breast cancer cell lines. Genetic and pharmacologic gain- and loss-of functions experiments verified the contribution of f-PIK3Cδ in TNBC cell invasion. Integrated secretomics and transcriptomics analyses revealed a paracrine mechanism via which f-PIK3Cδ confers its pro-tumorigenic effects. Inhibition of f-PIK3Cδ promoted the secretion of factors, including PLGF and BDNF, which led to upregulation of NR4A1 in TNBC cells where it acts as a tumor suppressor. Inhibition of PIK3Cδ in an orthotopic BC mouse model reduced tumor growth only after inoculation with fibroblasts, indicating a role of f-PIK3Cδ in cancer progression. Similar results were observed in the MMTV-PyMT transgenic BC mouse model, along with a decrease on tumor metastasis emphasizing the potential immune-independent effects of PIK3Cδ inhibition. Finally, analysis of BC patient cohorts and TCGA datasets identified f-PIK3Cδ (protein and mRNA levels) as an independent prognostic factor for overall and disease free survival, highlighting it as a therapeutic target for TNBC.

Authors

Teresa Gagliano, Kalpit Shah, Sofia Gargani, Liyan Lao, Mansour Alsaleem, Jianing Chen, Vasileios Ntafis, Penghan Huang, Angeliki Ditsiou, Viviana Vella, Kritika Yadav, Kamila Bienkowska, Giulia Bresciani, Kai Kang, Leping Li, Philip Carter, Graeme Benstead-Hume, Timothy O’Hanlon, Michael Dean, Frances M.G. Pearl, Soo Chin Lee, Emad A. Rakha, Andrew R Green, Dimitris L. Kontoyiannis, Erwei Song, Justin Stebbing, Georgios Giamas

Post-sepsis immunosuppression depends on NKT cell regulation of mTOR/IFNγ in NK cells

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Abstract

As treatment of the early, inflammatory phase of sepsis improves, post-sepsis immunosuppression and secondary infection have increased in importance. How early inflammation drives immunosuppression remains unclear. Although IFNγ typically helps microbial clearance, we found that increased plasma IFNγ in early clinical sepsis was associated with the later development of secondary Candida infection. Consistent with this observation, we found that exogenous IFNγ suppressed macrophage phagocytosis of zymosan in vivo, and antibody blockade of IFNγ after endotoxemia improved survival of secondary candidemia. Transcriptomic analysis of innate lymphocytes during endotoxemia suggested that NKT cells drove IFNγ production by NK cells via mTORC1. Activation of iNKT cells with glycolipid antigen drove immunosuppression. Deletion of iNKT cells in Cd1d-/- mice or inhibition of mTOR by rapamycin reduced immunosuppression and susceptibility to secondary Candida infection. Thus, although rapamycin is typically an immunosuppressive medication, in the context of sepsis, rapamycin has the opposite effect. These results implicated a NKT cell-mTOR-IFNγ axis in immunosuppression following endotoxemia or sepsis. In summary, in vivo iNKT cells activated mTORC1 in NK cells to produce IFNγ , which worsened macrophage phagocytosis, clearance of secondary Candida infection and mortality.

Authors

Edy Y. Kim, Hadas Ner-Gaon, Jack Varon, Aidan M. Cullen, Jingyu Guo, Jiyoung Choi, Diana Barragan-Bradford, Angelica Higuera, Mayra Pinilla-Vera, Samuel A.P. Short, Antonio J. Arciniegas-Rubio, Tomoyoshi Tamura, David E. Leaf, Rebecca M. Baron, Tal Shay, Michael B. Brenner

KLK6 expression in skin induces PAR1-mediated psoriasiform dermatitis and inflammatory joint disease

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Abstract

Kallikrein-related peptidase 6 (KLK6) is a secreted serine protease hypothesized to promote inflammation via cleavage of protease-activated receptors (PAR)1 and PAR2. KLK6 levels are elevated in multiple inflammatory and autoimmune conditions, but no definitive role in pathogenesis has been established. Here, we show that skin-targeted overexpression of KLK6 causes generalized, severe psoriasiform dermatitis with spontaneous development of debilitating psoriatic arthritis-like joint disease. The psoriatic skin and joint phenotypes are reversed by normalization of skin KLK6 levels and attenuated following genetic elimination of PAR1 but not PAR2. Conservation of this regulatory pathway was confirmed in human psoriasis using vorapaxar, an FDA-approved PAR1 antagonist, on explanted lesional skin from psoriasis patients. Beyond defining a critical role for KLK6-PAR1 signaling in promoting psoriasis, our results demonstrate that KLK6-PAR1-mediated inflammation in the skin alone is sufficient to drive inflammatory joint disease. Further, we identify PAR1 as a promising cytokine-independent target in therapy of psoriasis and psoriatic arthritis.

Authors

Allison C. Billi, Jessica E. Ludwig, Yi Fritz, Richard Rozic, William R. Swindell, Lam C. Tsoi, Dennis Gruszka, Shahla Abdollahi-Roodsaz, Xianying Xing, Doina Diaconu, Ranjitha Uppala, Maya I. Camhi, Philip A. Klenotic, Mrinal K. Sarkar, M. Elaine Husni, Jose U. Scher, Christine McDonald, J. Michelle Kahlenberg, Ronald J. Midura, Johann E. Gudjonsson, Nicole L. Ward

Ventromedial hypothalamic nucleus neuronal subset regulates blood glucose independently of insulin

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Abstract

To identify neurons that specifically increase blood glucose from among the diversely-functioning cell types in the ventromedial hypothalamic nucleus (VMN), we studied the cholecystokinin (CCK) receptor-B (CCKBR)-expressing VMN targets of glucose-elevating parabrachial nucleus neurons. Activating these VMNCCKBR neurons increased blood glucose. Furthermore, while silencing the broader VMN decreased energy expenditure and promoted weight gain without altering blood glucose, silencing VMNCCKBR neurons decreased hepatic glucose production (HGP), insulin-independently decreasing blood glucose without altering energy balance. Silencing VMNCCKBR neurons also impaired the counter-regulatory response (CRR) to insulin-induced hypoglycemia and glucoprivation and replicated hypoglycemia-associated autonomic failure (HAAF). Hence, VMNCCKBR cells represent a specialized subset of VMN cells that function to elevate glucose. These cells not only mediate the allostatic response to hypoglycemia, but also insulin-independently modulate the homeostatic setpoint for blood glucose, consistent with a role for the brain in the insulin-independent control of glucose homeostasis.

Authors

Jonathan N. Flak, Paulette Goforth, James Dell'Orco, Paul V. Sabatini, Chien Li, Nadejda Bozadjieva, Matthew J. Sorensen, Alec C. Valenta, Alan C. Rupp, Alison H. Affinati, Corentin Cras-Méneur, Ahsan Ansari, Jamie Sacksner, Nandan Kodur, Darleen A. Sandoval, Robert t. Kennedy, David Olson, Martin G. Myers Jr.

S100A8/A9 regulates CD11b expression and neutrophil recruitment during chronic tuberculosis

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Abstract

Neutrophil accumulation is associated with lung pathology during active tuberculosis (ATB). However, the molecular mechanism(s) by which neutrophils accumulate in the lung and contribute to TB immunopathology is not fully delineated. Using the well-established mouse model of TB, our new data provides evidence that the alarmin S100A8/A9 mediates neutrophil accumulation during progression to chronic TB. Depletion of neutrophils or S100A8/A9 deficiency resulted in improved Mycobacterium tuberculosis (Mtb) control during chronic but not acute TB. Mechanistically, we demonstrate that following Mtb infection, S100A8/A9 expression is required for upregulation of the integrin molecule CD11b specifically on neutrophils, mediating their accumulation during chronic TB disease. These findings are further substantiated by increased expression of S100A8 and S100A9 mRNA in whole blood in human TB progressors when compared to non-progressors, and rapidly decreased S100A8/A9 protein levels in the serum upon TB treatment. Furthermore, we demonstrate that S100A8/A9 serum levels along with chemokines are useful in distinguishing between ATB and asymptomatic Mtb-infected latent individuals. Thus, our results support targeting S100A8/A9 pathways as host-directed therapy for TB.

Authors

Ninecia R. Scott, Rosemary V. Swanson, Noor Al-Hammadi, Racquel Domingo-Gonzalez, Javier Rangel-Moreno, Belinda A. Kriel, Allison N. Bucsan, Shibali Das, Mushtaq Ahmed, Smriti Mehra, Puthayalai Treerat, Alfredo Cruz-Lagunas, Luis Jimenez-Alvarez, Marcela Muñoz-Torrico, Karen Bobadilla-Lozoya, Thomas Vogl, Gerhard Walzl, Nelita du Plessis, Deepak Kaushal, Thomas Scriba, Joaquin Zuñiga, Shabaana Khader

Minimal PD-1 expression in mouse and human NK cells under diverse conditions

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Abstract

PD-1 expression is a hallmark of both early antigen-specific T-cell activation and later chronic stimulation suggesting key roles in both naive T-cell priming and memory T-cell responses. Although important similarities exist between T cells and NK cells, there are critical differences reflecting their biology and functions. The putative role of PD-1 expression in NK cell immunoregulation has been controversial. Our objective was to comprehensively assess PD-1 expression on NK cells using multiple sources and readouts. Primary human tumor samples, ex vivo culturing, mouse tumors and viral models were all assessed using flow cytometry, qRT-PCR and RNA sequencing. We demonstrate that under multiple activating conditions, highly purified human and mouse NK cells consistently lack PD-1 expression despite the marked upregulation of other regulatory markers such as TIGIT. We further show that neither NK cells from T-cell deficient Rag2-/- mice nor from transgenic PD-1 reporter mice express PD-1 using tumor or viral infection models. Asialo-GM1 (ASGM1), a receptor commonly targeted for NK-specific depletion, was also expressed on activated T cells co-expressing PD-1 contributing to in vivo effects previously attributed to NK cells. These data have important implications when attempting to discern NK from T cell effects depending on the models used and whether PD-1 blockade will directly impact NK cell therapies.

Authors

Sean J. Judge, Cordelia Dunai, Ethan G. Aguilar, Sarah C. Vick, Ian R. Sturgill, Lam T. Khuat, Kevin M. Stoffel, Jonathan Van Dyke, Dan L. Longo, Morgan A. Darrow, Stephen K. Anderson, Bruce R. Blazar, Arta M. Monjazeb, Jonathan S. Serody, Robert J. Canter, William J. Murphy

SIRT2 protects peripheral neurons from cisplatin-induced injury by enhancing nucleotide excision repair

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Abstract

Platinum-based chemotherapy-induced peripheral neuropathy is one of the most common causes of dose reduction and discontinuation of life-saving chemotherapy in cancer treatment; it often causes permanent impairment of quality of life in cancer patients. The mechanisms that underlie this neuropathy are not defined, and effective treatment and prevention measures are not available. Here, we demonstrate that SIRT2 protected mice against cisplatin-induced peripheral neuropathy (CIPN). SIRT2 accumulated in the nuclei of dorsal root ganglion sensory neurons and prevented neuronal cell death following cisplatin treatment. Mechanistically, SIRT2, an NAD+-dependent deacetylase, protected neurons from cisplatin cytotoxicity by promoting transcription-coupled nucleotide excision repair (TC-NER) of cisplatin-induced DNA crosslinks. Consistent with this mechanism, pharmacological inhibition of NER using spironolactone abolished SIRT2-mediated TC-NER activity in differentiated neuronal cells and protection of neurons from cisplatin-induced cytotoxicity and CIPN in mice. Importantly, SIRT2’s protective effects were not evident in lung cancer cells in vitro or in tumors in vivo. Taken together, our results identified SIRT2’s function in the NER pathway as a key underlying mechanism of preventing CIPN, warranting future investigation of SIRT2 activation-mediated neuroprotection during platinum-based cancer treatment.

Authors

Manchao Zhang, Wuying Du, Scarlett M. Acklin, Shengkai Jin, Fen Xia

PLA2G1B is involved in CD4 anergy and CD4 lymphopenia in HIV-infected patients

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Abstract

The precise mechanism leading to profound immunodeficiency of HIV-infected patients is still only partially understood. Here, we show that more than 80% of CD4 T cells from HIV-infected patients have morphological abnormalities. Their membranes exhibited numerous large abnormal membrane microdomains (aMMDs), which trap and inactivate physiological receptors, such as that for IL-7. In patient plasma, we identified phospholipase A2 group IB (PLA2G1B) as the key molecule responsible for the formation of aMMDs. At physiological concentrations, PLA2G1B synergized with the HIV gp41 envelope protein, which appears to be a driver that targets PLA2G1B to the CD4 T-cell surface. The PLA2G1B/gp41 pair induced CD4 T cell unresponsiveness (anergy). At high concentrations in vitro, PLA2G1B acted alone, independently of gp41, and inhibited the IL-2, IL-4, and IL-7 responses, as well as TCR-mediated activation and proliferation, of CD4 T cells. PLA2G1B also decreased CD4 T-cell survival in vitro, likely playing a role in CD4 lymphopenia in conjunction with its induced IL-7 receptor defects. The effects on CD4 T-cell anergy could be blocked by a PLA2G1B-specific neutralizing mAb in vitro and in vivo. The PLA2G1B/gp41 pair constitutes a new mechanism of immune dysfunction and a compelling target for boosting immune responses in HIV-infected patients.

Authors

Julien Pothlichet, Thierry Rose, Florence Bugault, Louise Jeammet, Annalisa Meola, Ahmed Haouz, Frederick Saul, David Geny, José Alcami, Ezequiel Ruiz-Mateos Carmona, Luc Teyton, Gérard Lambeau, Jacques Thèze

IRF4 instructs effector Treg differentiation and immune suppression in human cancer

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Abstract

The molecular mechanisms responsible for the high immunosuppressive capacity of CD4+ regulatory T cells (Tregs) in tumors are poorly known. High-dimensional single cell profiling of T cells from chemotherapy-naïve individuals with non-small cell lung cancer identified the transcription factor IRF4 as specifically expressed by a subset of intratumoral CD4+ effector Tregs with superior suppressive activity. In contrast to the IRF4– counterparts, IRF4+ Tregs expressed a vast array of suppressive molecules, and their presence correlated with multiple exhausted subpopulations of T cells. Integration of transcriptomic and epigenomic data revealed that IRF4, either alone or in combination with its partner BATF, directly controlled a molecular program responsible for immunosuppression in tumors. Accordingly, deletion of Irf4 exclusively in Tregs resulted in delayed tumor growth in mice while the abundance of IRF4+ Tregs correlated with poor prognosis in patients with multiple human cancers. Thus, a common mechanism underlies immunosuppression in the tumor microenvironment irrespectively of the tumor type.

Authors

Giorgia Alvisi, Jolanda Brummelman, Simone Puccio, Emilia Maria Cristina Mazza, Elisa Paoluzzi Tomada, Agnese Losurdo, Veronica Zanon, Clelia Peano, Federico S. Colombo, Alice Scarpa, Marco Alloisio, Ajithkumar Vasanthakumar, Rahul Roychoudhuri, Marinos Kallikourdis, Massimiliano Pagani, Egesta Lopci, Pierluigi Novellis, Jonas Blume, Axel Kallies, Giulia Veronesi, Enrico Lugli

DNA hyper-methylation during Tuberculosis dampens host immune responsiveness

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Abstract

Mycobacterium tuberculosis (Mtb) has co-evolved with humans for millennia and developed multiple mechanisms to evade host immunity. Restoring host immunity in order to improve outcomes and potentially shorten existing therapy will require identifying the full complement by which host immunity is inhibited. Perturbing host DNA methylation is a mechanism induced by chronic infections such as HIV, HPV, LCMV and schistosomiasis to evade host immunity. Here, we evaluated the DNA methylation status of TB patients and their asymptomatic household contacts demonstrating that TB patients have DNA hyper-methylation of the IL-2-STAT5, TNF-NF-ϰB and IFN-γ signaling pathways. By MSRE-qPCR, multiple genes of the IL-12-IFN-γ signaling pathway (IL12B, IL12RB2, TYK2, IFNGR1, JAK1 and JAK2) were hyper-methylated in TB patients. The DNA hyper-methylation of these pathways is associated with decreased immune responsiveness with decreased mitogen-induced upregulation of IFN-γ, TNF, IL-6, CXCL9, CXCL10 and IL-1β production. The DNA hyper-methylation of the IL-12-IFN-γ pathway was associated with decreased IFN-γ induced gene expression and decreased IL-12 inducible up-regulation of IFN-γ. This work demonstrates that immune cells from TB patients are characterized by DNA hyper-methylation of genes critical to mycobacterial immunity resulting in decreased mycobacteria-specific and non-specific immune responsiveness.

Authors

Andrew DiNardo, Kimal Rajapakshe, Tomoki Nishiguchi, Godwin Mtetwa, Sandra L. Grimm, Qiniso Dlamini, Jaquiline Kahari, Sanjana Mahapatra, Alexander W. Kay, Gugu Maphalala, Emily M. Mace, George Makedonas, Jeffrey D. Cirillo, Mihai Netea, Reinout van Crevel, Cristian Coarfa, Anna M. Mandalakas

Tissue-resident T cell derived cytokines eliminate herpes simplex virus-2 infected cells

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Abstract

The mechanisms underlying rapid elimination of herpes simplex virus-2 (HSV-2) in the human genital tract despite low tissue-resident CD8+ and CD4+ T-cell density (TRM) are unknown. We analyzed shedding episodes during chronic HSV-2 infection: viral clearance always predominated within 24 hours of detection even if viral load exceeded 107 HSV DNA copies; surges in granzyme B and interferon-γ occurred within the early hours after reactivation and correlated with local viral load. We next developed an agent-based mathematical model of an HSV-2 genital ulcer to integrate mechanistic observations of TRM in situ proliferation, trafficking, cytolytic effects and cytokine alarm signaling from murine studies with viral kinetics, histopathology and lesion size data from humans. A sufficiently high density of HSV-2 specific TRM predicted rapid elimination of infected cells, but our data suggest that such TRM densities are relatively uncommon in infected tissues. At lower, more commonly observed TRM densities, TRM must initiate a rapidly diffusing, polyfunctional cytokine response with activation of bystander T cells in order to eliminate a majority of infected cells and eradicate briskly spreading HSV-2 infection.

Authors

Pavitra Roychoudhury, David A. Swan, Elizabeth R. Duke, Lawrence Corey, Jia Zhu, Veronica A. Davé, Laura E. Richert-Spuhler, Jennifer M. Lund, Martin Prlic, Joshua T. Schiffer

Salt-inducible kinase 1 maintains HDAC7 stability to promote pathologic cardiac remodeling

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Abstract

Salt inducible kinases (SIKs) are key regulators of cellular metabolism and growth, but their role in cardiomyocyte plasticity and heart failure pathogenesis remains unknown. Here, we showed that loss of SIK1 kinase activity protected against adverse cardiac remodeling and heart failure pathogenesis in rodent models and human iPSC-derived cardiomyocytes. We found that SIK1 phosphorylated and stabilized histone deacetylase 7 (HDAC7) protein during cardiac stress, an event that is required for pathologic cardiomyocyte remodeling. Gain- and loss-of-function studies of HDAC7 in cultured cardiomyocytes implicated HDAC7 as a pro-hypertrophic signaling effector that can induce c-Myc expression, indicating a functional departure from the canonical MEF2 co-repressor function of class IIa HDACs. Taken together, our findings reveal what we believe to be a previously unrecognized role for a SIK1-HDAC7 axis in regulating cardiac stress responses and implicate this pathway as a potential target in human heart failure.

Authors

Austin Hsu, Qiming Duan, Sarah McMahon, Yu Huang, Sarah A.B. Wood, Nathanael S. Gray, Biao Wang, Benoit G. Bruneau, Saptarsi M. Haldar

Hepatic Slug epigenetically promotes liver lipogenesis, fatty liver disease, and type 2 diabetes

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Abstract

De novo lipogenesis is tightly regulated by insulin and nutritional signals to maintain metabolic homeostasis; excessive lipogenesis induces lipotoxicity, leading to nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes. Genetic lipogenic programs have been extensively investigated, but epigenetic regulation of lipogenesis is poorly understood. Here, we identified Slug as an important epigenetic regulator of lipogenesis. Hepatic Slug levels were markedly upregulated in mice by either feeding or insulin treatment. In primary hepatocytes, insulin stimulation increased Slug expression, stability, and interactions with epigenetic enzyme lysine-specific demethylase-1 (Lsd1). Slug bound to the fatty acid synthase (Fasn) promoter where Slug-associated Lsd1 catalyzed H3K9 demethylation, thereby stimulating Fasn expression and lipogenesis. Ablation of Slug blunted insulin-stimulated lipogenesis; conversely, overexpression of Slug, but not a Lsd1 binding-defective Slug mutant, stimulated Fasn expression and lipogenesis. Lsd1 inhibitor treatment also blocked Slug-stimulated lipogenesis. Remarkably, hepatocyte-specific deletion of Slug inhibited the hepatic lipogenic program and protected against obesity-associated NAFLD, insulin resistance, and glucose intolerance in mice. Conversely, liver-restricted overexpression of Slug, but not the Lsd1 binding-defective Slug mutant, had the opposite effects. These results unveil an insulin/Slug/Lsd1/H3K9 demethylation lipogenic pathway that promotes NAFLD and type 2 diabetes.

Authors

Yan Liu, Haiyan Lin, Lin Jiang, Qingsen Shang, Lei Yin, Jiandie D. Lin, Wen-Shu Wu, Liangyou Rui

Muscle derived interleukin-6 increases exercise capacity by signaling in osteoblasts

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Abstract

Given the numerous health benefits of exercise, understanding how exercise capacity is regulated is a question of paramount importance. Circulating interleukin-6 (IL-6) levels surge during exercise and IL-6 favors exercise capacity. However, neither the cellular origin of circulating IL-6 during exercise nor the means by which this cytokine enhances exercise capacity have been formally established yet. Here we show through genetic means that the majority of circulating IL-6 detectable during exercise originates from muscle and that to increase exercise capacity, IL-6 must signal in osteoblasts to favor osteoclast differentiation and the release of bioactive osteocalcin in the general circulation. This explains why mice lacking the IL-6 receptor only in osteoblasts exhibit a deficit in exercise capacity of similar severity to the one seen in mice lacking muscle-derived IL-6 (mIL-6), and why this deficit is correctable by osteocalcin but not by IL-6. Furthermore, in agreement with the notion that IL-6 acts through osteocalcin, we demonstrate that mIL-6 promotes nutrient uptake and catabolism into myofibers during exercise in an osteocalcin-dependent manner. Lastly, we show that the crosstalk between osteocalcin and IL-6 is conserved between rodents and humans. This study provides evidence that a muscle-bone-muscle endocrine axis is necessary to increase muscle function during exercise in rodents and humans.

Authors

Subrata Chowdhury, Logan C Schulz, Biagio Palmisano, Parminder Singh, Julian Meyer Berger, Vijay K. Yadav, Paula Mera, Helga Ellingsgaard, Juan Hidalgo, Jens C. Brüning, Gerard Karsenty

Single residue in CD28-costimulated CAR T cells limits long-term persistence and antitumor durability

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Abstract

Chimeric antigen receptor (CAR) T cell therapies can eliminate relapsed and refractory tumors, but the durability of anti-tumor activity requires in vivo persistence. Differential signaling through the CAR costimulatory domain can alter the T cell metabolism, memory differentiation, as well as influence long-term persistence. CAR-T cells costimulated with 4-1BB or ICOS persist in xenograft models but those constructed with CD28 exhibit rapid clearance. Here, we show that a single amino acid residue in CD28 drove T cell exhaustion and hindered the persistence of CD28-based CAR-T cells and substituting this asparagine to phenylalanine (CD28-YMFM) promoted durable anti-tumor control. In addition, CD28-YMFM CAR-T cells exhibited reduced T cell differentiation and exhaustion as well as increased skewing towards Th17 cells. Reciprocal modification of ICOS-containing CAR-T cells abolished in vivo persistence and anti-tumor activity. This finding suggests modifications to the co-stimulatory domains of CAR-T cells can enable longer persistence and thereby improve anti-tumor response.

Authors

Sonia Guedan, Aviv Madar, Victoria Casado-Medrano, Carolyn E. Shaw, Anna Wing, Fang Liu, Regina M. Young, Carl H. June, Avery D. Posey Jr.

Distinct immune characteristics distinguish hereditary and idiopathic chronic pancreatitis

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Abstract

Chronic pancreatitis (CP) is considered an irreversible fibroinflammatory pancreatic disease. Despite numerous animal model studies, questions remain about local immune characteristics in human CP. We profiled pancreatic immune cell characteristics in control organ donors and CP patients that included hereditary and idiopathic CP undergoing total pancreatectomy with islet auto-transplantation. Flow cytometric analysis revealed a significant increase in the frequency of CD68+ macrophages in idiopathic CP. In contrast, hereditary CP showed a significant increase in CD3+ T cell frequency, which prompted us to investigate the T cell receptor β (TCRβ) repertoire in CP and controls. TCRβ-sequencing revealed a significant increase in TCRβ repertoire diversity and reduced clonality in both CP groups versus controls. Interestingly, we observed differences in Vβ-Jβ gene family usage between hereditary and idiopathic CP and a positive correlation of TCRβ rearrangements with disease severity scores. Immunophenotyping analyses in hereditary and idiopathic CP pancreata indicate differences in innate and adaptive immune responses, which highlights differences in immunopathogenic mechanism of disease among subtypes of CP. TCR repertoire analysis further suggests a role for specific T cell responses in hereditary versus idiopathic CP pathogenesis providing new insights into immune responses associated with human CP.

Authors

Bomi Lee, Julia Z. Adamska, Hong Namkoong, Melena D. Bellin, Joshua J. Wilhelm, Gregory L. Szot, David M. Louis, Mark M. Davis, Stephen Pandol, Aida Habtezion

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

A Plasmodium vivax experimental human infection model for evaluating the efficacy of interventions

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Abstract

Background: Interventions that interrupt Plasmodium vivax transmission or eliminate dormant P. vivax liver-stage parasites will be essential for malaria elimination. Development of these interventions has been hindered by the lack of P. vivax in vitro culture and could be accelerated by a safe and reproducible clinical model in malaria-naïve individuals. Method: Healthy, malaria-naïve adults were enrolled in two studies to assess the safety and infectivity and transmissibility of a new P. vivax isolate. Participants (Study 1; n=2, Study 2; n=24) were inoculated with P. vivax-infected red blood cells to initiate infection, and were treated with artemether-lumefantrine (Study 1) or chloroquine (Study 2). Primary endpoints were safety and infectivity of the new isolate. In Study 2, transmission to mosquitoes was also evaluated using mosquito feeding assays, and sporozoite viability was assessed using in vitro cultured hepatocytes. Results: Parasitaemia and gametocytemia developed in all participants and was cleared by antimalarial treatment. Adverse events were mostly mild or moderate and none were serious. Participants were infectious to Anopheles mosquitoes at peak gametocytemia 69% (11/16). Mosquito infection rates reached 97% following membrane feeding with gametocyte-enriched blood, and sporozoites developed into liver-stage schizonts in culture. Conclusion: We have demonstrated the safe, reproducible, and efficient transmission of P. vivax gametocytes from humans to mosquitoes, and have established an experimental model that will accelerate the development of interventions targeting multiple stages of the P. vivax life cycle. Trial registration: ACTRN12614000930684 and ACTRN12616000174482. Funding: (Australian) NHMRC Program Grant: 1132975 (Study 1). Bill & Melinda Gates Foundation (OPP1111147) (Study 2).

Authors

Katharine A. Collins, Claire Y.T. Wang, Matthew Adams, Hayley Mitchell, Gregory J. Robinson, Melanie Rampton, Suzanne Elliott, Anand Odedra, David S. Khoury, Emma Ballard, Todd B. Shelper, Leonardo Lucantoni, Vicky M. Avery, Stephan Chalon, Jörg J. Möhrle, James S. McCarthy