Inflammatory mediators released by cancer cells promote the induction of immune suppression and tolerance in myeloid cells. Interleukin-1 receptor-associated kinase-3 (IRAK3) is a pseudokinase that inhibits IL-1/TLR signaling but its role in patients treated with immune checkpoint blockade (ICB) therapy remains unclear. Using RNAseq data from the IMvigor210 trial, we found that tumors with high IRAK3 expressions showed enriched anti-inflammatory pathways and worse clinical response to ICB therapy. Upon IRAK3 protein deletion with CRISPR/Cas9, primary human monocytes displayed altered global protein expression and phosphorylation in quantitative proteomics and released more pro-inflammatory cytokines in response to stimulation. Bone-marrow derived macrophages from an IRAK3 CRISPR knockout (KO) mouse model demonstrated a pro-inflammatory phenotype and enhanced sensitivity to TLR agonists, compared to wild-type cells. IRAK3 deficiency delayed the growth of carcinogen-induced and oncogene-driven murine cancer cells and induced enhanced activation in myeloid cells and T cells. Upon ICB treatment, IRAK3 KO mice showed enrichment of TCF1+PD-1+ stem-like memory CD8+ T cells and resulted in superior growth inhibition of immunologically cold tumors in vivo. Altogether, our study demonstrated a novel cancer-driven immune tolerance program controlled by IRAK3 in humans and mice and proposed its suitability as an immunotherapy target.
Gürcan Tunalı, Marta Rúbies Bedós, Divya Nagarajan, Patrik Fridh, Irineos Papakyriacou, Yumeng Mao
Hypersecretory malignant cells underlie therapeutic resistance, metastasis, and poor clinical outcomes. However, the molecular basis for malignant hypersecretion remains obscure. Here, we showed that epithelial-to-mesenchymal transition (EMT) initiates exocytic and endocytic vesicular trafficking programs in lung cancer. The EMT-activating transcription factor ZEB1 executed a PI4KIIIβ-to-PI4KIIα (PI4K2A)-dependency switch that drove PI4P synthesis in Golgi and endosomes. EMT enhanced the vulnerability of lung cancer cells to PI4K2A small molecule antagonists. PI4K2A formed a MYOIIA-containing protein complex that facilitated secretory vesicle biogenesis in the Golgi, thereby establishing a hypersecretory state involving osteopontin (SPP1) and other pro-metastatic ligands. In the endosomal compartment, PI4K2A accelerated recycling of SPP1 receptors to complete an SPP1-dependent autocrine loop and interacted with HSP90 to prevent lysosomal degradation of AXL receptor tyrosine kinase, a driver of cell migration. These results show that EMT coordinates exocytic and endocytic vesicular trafficking to establish a therapeutically actionable hypersecretory state that drives lung cancer progression.
Xiaochao Tan, Guan-Yu Xiao, Shike Wang, Lei Shi, Yanbin Zhao, Xin Liu, Jiang Yu, William K. Russell, Chad J. Creighton, Jonathan M. Kurie
Induction of lipid-laden foamy macrophages is a cellular hallmark of tuberculosis (TB) disease, which involves transformation of infected phagolysomes from a site of killing into a nutrient-rich replicative niche. Here we show that a terpenyl nucleoside shed from Mycobacterium tuberculosis (Mtb), 1-tuberculosinyladenosine (1-TbAd), causes lysosomal maturation arrest and autophagy blockade, leading to lipid storage in M1 macrophages. Pure 1-TbAd, or infection with terpenyl nucleoside-producing Mtb, caused intralysosomal and peribacillary lipid storage patterns that match both the molecules and subcellular locations known in foamy macrophages. Lipidomics showed that 1-TbAd induced storage of triacylglycerides and cholesterylesters, and 1-TbAd increased Mtb growth under conditions of restricted lipid access in macrophages. Further, lipidomics dentified 1-TbAd induced lipid substrates that define Gaucher's disease, Wolman's disease and other inborn lysosomal storage diseases. These data identify genetic and molecular causes of Mtb-induced lysosomal failure, leading to successful testing of an gonist of TRPML1 calcium channels that reverses lipid storage in cells. These data establish the host-directed cellular functions of an orphan effector molecule that promotes survival in macrophages, providing both an upstream cause and detailed picture of lysosome failure in foamy macrophages.
Melissa Bedard, Sanne van der Niet, Elliott M. Bernard, Gregory H. Babunovic, Tan-Yun Cheng, Beren Aylan, Anita E. Grootemaat, Sahadevan Raman, Laure Botella, Eri Ishikawa, Mary P. O'Sullivan, Seonadh O'Leary, Jacob A. Mayfield, Jeffrey Buter, Adriaan J. Minnaard, Sarah M. Fortune, Leon O. Murphy, Daniel S. Ory, Joseph Keane, Sho Yamasaki, Maximiliano Gabriel Gutierrez, Nicole van der Wel, D. Branch Moody
Sepsis pathogenesis is complex and heterogeneous; hence, a precision medicine strategy is needed. Acute kidney injury (AKI) following sepsis portends higher mortality. Overproduction of mitochondrial reactive oxygen species (mtROS) is a potential mediator of sepsis and sepsis-induced AKI. BAM15, a chemical uncoupler, dissipates mitochondrial proton gradients without generating mtROS. We injected BAM15 into mice at 0, 6, or 12 hours after cecal ligation and puncture (CLP) treated with fluids and antibiotics. BAM15 reduced mortality, even after 12 hours, when mice were ill, and BAM15 reduced kidney damage and splenic apoptosis. Serial plasma and urinary mitochondrial DNA (mtDNA) levels increased post-CLP and decreased after BAM15 administration (at 0 or 6 hours). In vitro septic serum proportionately increased mtROS overproduction and mtDNA release from kidney tubule cells, which BAM15 prevented. BAM15 decreased neutrophil apoptosis, mtDNA release; neutrophil depletion counteracted BAM15 benefits. Further, mtDNA injection in vivo replicated inflammation and kidney injury, which was prevented by BAM15. A large dose of exogenous mtDNA reversed protection by BAM15. We conclude that BAM15 is an effective preventive and therapeutic candidate in experimental sepsis, and that BAM15 and mtDNA, a potential drug-companion diagnostic/drug efficacy pair for clinical sepsis, are mechanistically linked via mtROS.
Naoko Tsuji, Takayuki Tsuji, Tetsushi Yamashita, Naoki Hayase, Xuzhen Hu, Peter S.T. Yuen, Robert A. Star
Major depressive disorder is a common and devastating psychiatric disease, the prevalence and burden are substantially increasing worldwide. Multiple studies of depression patients have implicated glucose metabolic dysfunction in the pathophysiology of depression. However, the molecular mechanisms by which glucose and related metabolic pathways modulate depressive-like behaviors are largely uncharacterized. UDP-GlcNAc is a glucose metabolite with pivotal functions as a donor molecule for O-GlcNAcylation. O-GlcNAc transferase (OGT), a key enzyme in protein O-GlcNAcylation, catalyzes protein posttranslational modification by O-GlcNAc and acts as a stress sensor. Here, we show that Ogt mRNA was increased in depression patients and that astroglial OGT expression was specifically upregulated in the medial prefrontal cortex of susceptible mice after chronic social defeat stress. The selective deletion of astrocytic OGT resulted in antidepressant-like behaviors, moreover, astrocytic OGT in the mPFC bidirectionally regulated vulnerability to social stress. Furthermore, OGT modulated glutamatergic synaptic transmission through O-GlcNAcylation of glutamate transporter-1 (GLT-1) in astrocytes. OGT astrocyte-specific knockout preserved the neuronal morphology atrophy and Ca2+ activity deficits caused by chronic stress and resulted in antidepressant effects. Altogether, our study reveals that astrocytic OGT in the mPFC regulates depressive-like behaviors through the O-GlcNAcylation of GLT-1 and could be a potential target for antidepressants.
Jun Fan, Fang Guo, Ran Mo, Liang-Yu Chen, Jiawen Mo, Cheng-lin Lu, Jing Ren, Qiuling Zhong, Xiaojing Kuang, Youlu Wen, Ting-Ting Gu, Jinming Liu, Shuji Li, Yingying Fang, Cunyou Zhao, Tian-Ming Gao, Xiong Cao
BACKGROUND. The role of host immunity in emergence of evasive SARS-CoV-2 Spike mutations under therapeutic monoclonal antibody (mAb) pressure remains to be explored. METHODS. In a prospective, observational, monocentric ORCHESTRA cohort study, conducted between March 2021 and November 2022, mild-to-moderately ill COVID-19 patients (n=204) receiving bamlanivimab, bamlanivimab/etesevimab, casirivimab/imdevimab, or sotrovimab were longitudinally studied over 28 days for viral loads, de novo Spike mutations, mAb kinetics, seroneutralization against infecting variants of concern, and T-cell immunity. Additionally, a machine learning-based circulating immune-related (CIB) biomarker profile predictive of evasive Spike mutations was constructed and confirmed in an independent dataset (n=19) that included patients receiving sotrovimab or tixagevimab/cilgavimab. RESULTS. Patients treated with various mAbs developed evasive Spike mutations with remarkable speed and high specificity to the targeted mAb-binding sites. Immunocompromised patients receiving mAb therapy not only continued to display significantly higher viral loads, but also showed higher likelihood of developing de novo Spike mutations. Development of escape mutants also strongly correlated with neutralizing capacity of the therapeutic mAbs and T-cell immunity, suggesting immune pressure as an important driver of escape mutations. Lastly, we showed that an anti-inflammatory and healing-promoting host milieu facilitates Spike mutations, where 4 CIBs identified patients at high risk of developing escape mutations against therapeutic mAbs with high accuracy. CONCLUSIONS. Our data demonstrate that host-driven immune and non-immune responses are essential for development of mutant SARS-CoV-2. These data also support point-of-care decision-making in reducing the risk of mAb treatment failure and improving mitigation strategies for possible dissemination of escape SARS-CoV-2 mutants.
Akshita Gupta, Angelina Konnova, Mathias Smet, Matilda Berkell, Alessia Savoldi, Matteo Morra, Vincent Van averbeke, Fien H.R. De Winter, Denise Peserico, Elisa Danese, An Hotterbeekx, Elda Righi, Pasquale De Nardo, Evelina Tacconelli, Surbhi Malhotra-Kumar, Samir Kumar-Singh
Uncontrolled inflammation occurred in sepsis results in multiple organ injuries and shock, which contributes to the death of sepsis patients. However, the regulatory mechanisms that restrict excessive inflammation are still elusive. Here we identified an immunoglobulin-like receptor called Signaling Lymphocyte Activation Molecular Family-7 (SLAMF7), as a key suppressor of inflammation during sepsis. We found that the expression of SLAMF7 on monocytes/ macrophages was significantly elevated in patients with sepsis and septic mice. SLAMF7 attenuated TLR-dependent MAPK and NF-κB signaling activation in macrophages by co-operating with Src homology 2-containing inositol ‑5'‑ phosphatase1 (SHIP1). Furthermore, SLAMF7 interacted with SHIP1 and TNF receptor associated factor 6 (TRAF6) to inhibit K63 ubiquitination of TRAF6. In addition, we found that tyrosine phosphorylation sites within the intracellular domain of SLAMF7 and the phosphatase domain of SHIP1 were indispensable for the interaction of SLAMF7/SHIP1/TRAF6 and SLAMF7-mediated modulation of cytokine production. Finally, we demonstrated that SLAMF7 protected against lethal sepsis and endotoxemia by down-regulating macrophage pro-inflammatory cytokines and suppressing inflammation-induced organ damage. Taken together, our findings reveal a negatively regulatory role of SLAMF7 in polymicrobial sepsis, which provides sights into the treatment of sepsis.
Yongjian Wu, Qiaohua Wang, Miao Li, Juanfeng Lao, Huishu Tang, Siqi Ming, Minhao Wu, Sitang Gong, Linhai Li, Lei Liu, Xi Huang
Tumor suppressor TP53 is the most frequently mutated gene in human cancers. Mutant p53 (mutp53) proteins often accumulate to very high levels in human cancers to promote cancer progression through the gain-of-function (GOF) mechanism. Currently, the mechanism underlying mutp53 accumulation and GOF is incompletely understood. Here, we identified TRIM21 as a critical E3 ubiquitin ligase of mutp53 by screening for specific mutp53-interacting proteins. TRIM21 directly interacted with mutp53 but not wild-type p53, resulting in ubiquitination and degradation of mutp53 to suppress mutp53 GOF in tumorigenesis. TRIM21 deficiency in cancer cells promoted mutp53 accumulation and GOF in tumorigenesis. Compared with p53R172H knock-in mice, which displayed mutp53 accumulation specifically in tumors but not normal tissues, TRIM21 deletion in p53R172H knock-in mice resulted in mutp53 accumulation in normal tissues, an earlier tumor onset, and a shortened lifespan of mice. Furthermore, TRIM21 was frequently downregulated in some human cancers, including colorectal and breast cancers, and low TRIM21 expression was associated with poor prognosis in patients with cancers carrying mutp53. Our results revealed a critical mechanism underlying mutp53 accumulation in cancers, and also uncovered an important tumor-suppressive function of TRIM21 and its mechanism in cancers carrying mutp53.
Juan Liu, Cen Zhang, Dandan Xu, Tianliang Zhang, Chun-Yuan Chang, Jianming Wang, Jie Liu, Lanjing Zhang, Bruce G. Haffty, Wei-Xing Zong, Wenwei Hu, Zhaohui Feng
Multiple sclerosis (MS) is a progressive inflammatory-demyelinating disease of the central nervous system. Increasing evidence suggests that vulnerable neurons in MS exhibit fatal metabolic exhaustion over time, a phenomenon hypothesized to be caused by chronic hyperexcitability. Axonal Kv7 (outward rectifying) and oligodendroglial Kir4.1 (inward rectifying) potassium channels have important roles in regulating neuronal excitability at and around nodes of Ranvier. Here, we studied the spatial and functional relationship between neuronal Kv7 and oligodendroglial Kir4.1 channels and assessed the transcriptional and functional signatures of cortical and retinal projection neurons under physiological and inflammatory-demyelinating conditions. We found that both channels became dysregulated in MS and experimental autoimmune encephalomyelitis (EAE) with Kir4.1 channels being chronically downregulated and Kv7 channel subunits being transiently upregulated during inflammatory demyelination. Further, we observed that pharmacological Kv7 channel opening with retigabine reduced neuronal hyperexcitability in human and EAE neurons, improved clinical EAE signs and rescued neuronal pathology in oligodendrocyte-Kir4.1-deficient mice. In summary, our findings indicate that neuron-oligodendrocyte compensatory interactions promote resilience through Kv7 and Kir4.1 channels and suggest pharmacological activation of nodal Kv7 channels as a neuroprotective strategy against inflammatory demyelination.
Hannah Kapell, Luca Fazio, Julia Dyckow, Sophia Schwarz, Andrés Cruz-Herranz, Christina Mayer, Joaquin Campos, Elisa D´Este, Wiebke Möbius, Christian Cordano, Anne-Katrin Pröbstel, Marjan Gharagozloo, Amel Zulji, Venu Narayanan Naik, Anna-Katharina Delank, Manuela Cerina, Thomas Müntefering, Celia Lerma-Martin, Jana K. Sonner, Jung H. Sin, Paul Disse, Nicole Rychlik, Khalida Sabeur, Manideep Chavali, Rajneesh Srivastava, Matthias Heidenreich, Kathryn C. Fitzgerald, Guiscard Seebohm, Christine Stadelmann, Bernhard Hemmer, Michael Platten, Thomas J. Jentsch, Maren Engelhardt, Thomas Budde, Klaus-Armin Nave, Peter A. Calabresi, Manuel A. Friese, Ari J. Green, Claudio Acuna, David H. Rowitch, Sven G. Meuth, Lucas Schirmer
The non-essential amino acid asparagine can only be synthesized de novo by the enzymatic activity of asparagine synthetase (ASNS). While ASNS and asparagine have been implicated in the response to numerous metabolic stressors in cultured cells, the in vivo relevance of this enzyme in stress-related pathways remains unexplored. Here, we found ASNS to be expressed in pericentral hepatocytes, a population of hepatic cells specialized in xenobiotic detoxification. ASNS expression was strongly enhanced in two models of acute liver injury: carbon tetrachloride (CCl4) and acetaminophen (APAP). We found that mice with hepatocyte-specific Asns deletion (Asnshep-/-) were more prone to pericentral liver damage than their control (Asnshep+/+) littermates after toxin exposure. This phenotype could be reverted by intravenous administration of asparagine. Unexpectedly, the stress-induced upregulation of ASNS involved an ATF4-independent, non-canonical pathway mediated by the nuclear receptor, liver receptor homolog 1 (LRH-1; NR5A2). Altogether, our data indicate that the induction of the asparagine-producing enzyme ASNS acts as an adaptive mechanism to constrain the necrotic wave that follows toxin administration and provide proof of concept that intravenous delivery of asparagine can dampen hepatotoxin-induced pericentral hepatocellular death.
Yu Sun, Hadrien Demagny, Adrien Faure, Francesca Pontanari, Antoine Jalil, Nadia Bresciani, Ece Yildiz, Melanie Korbelius, Alessia Perino, Kristina Schoonjans
BACKGROUND. Merkel cell carcinoma (MCC) is an aggressive neuroendocrine (NE) skin cancer caused by severe UV-induced mutations or expression of Merkel cell polyomavirus (MCPyV) large and small T antigens (LT and ST). Despite deep genetic differences between MCPyV-positive and -negative subtypes, current clinical diagnostic markers are indistinguishable between subtypes and the expression profile of MCC tumors is unexplored. METHODS. Here we leveraged bulk and single-cell RNA sequencing of patient-derived tumor biopsies and cell lines to explore the underlying transcriptional diversity of MCC. RESULTS. Strikingly, MCC samples could be separated into transcriptional subtypes that were independent of MCPyV status. Instead, we observed an inverse correlation between a NE gene signature and the Hippo pathway transcription factors Yes1-associated transcriptional regulator (YAP1) and WW domain containing transcriptional regulator (WWTR1). This inverse correlation was present at the transcript and protein levels in the tumor biopsies as well as in established and patient-derived cell lines. Mechanistically, expression of YAP1 or WWTR1 in a MCPyV-positive MCC cell line induced cell-cycle arrest at least in part through TEAD-dependent transcriptional repression of MCPyV LT. CONCLUSION. These findings describe previously unrecognized heterogeneity in NE gene expression within MCC and support the model that YAP1/WWTR1 silencing is essential for the development of MCPyV-positive MCC. FUNDING. US Public Health Service grants R35CA232128, P01CA203655, and P30CA06516.
Thomas C. Frost, Ashley K. Gartin, Mofei Liu, Jingwei Cheng, Harita Dharaneeswaran, Derin B. Keskin, Catherine J. Wu, Anita Giobbie-Hurder, Manisha Thakuria, James A. DeCaprio
BACKGROUND. Relatlimab+nivolumab (anti-LAG3+anti-PD1) has been approved by FDA as a 1st-line therapy in stage III/IV melanoma, but its detailed effect on the immune system is unknown. METHODS. We evaluated blood samples from 40 immunotherapy-naïve or prior immunotherapy-refractory patients with metastatic melanoma treated with anti-LAG3+anti-PD1 in a phase I trial (NCT01968109) using single-cell RNA and T cell receptor (TCR) sequencing (scRNA+TCRαβ-seq) combined with other multiomics profiling. RESULTS. The highest LAG3 expression was noted in NK cells, regulatory T cells (Tregs), and CD8+ T cells, and these cell populations underwent the most significant changes during the treatment. Adaptive NK cells were enriched in responders and underwent profound transcriptomic changes during the therapy resulting in an active phenotype. LAG3+ Tregs expanded but based on the transcriptome profile became metabolically silent during the treatment. Lastly, higher baseline TCR clonality was observed in responding patients, and their expanding CD8+ T cell clones gained more cytotoxic and NK-like phenotype. CONCLUSION. Anti-LAG3+anti-PD1 therapy has profound effects on NK cells and Tregs in addition to CD8+ T cells. TRIAL REGISTRATION. ClinicalTrials.gov (NCT01968109) FUNDING. Cancer Foundation Finland, Sigrid Juselius Foundation, Signe and Ane Gyllenberg Foundation, Relander Foundation, State funding for university-level health research in Finland, a Helsinki Institute of Life Sciences Fellow grant, Academy of Finland, and an investigator-initiated research grant from BMS.
Jani Huuhtanen, Henna H.E. Kasanen, Katriina Peltola, Tapio Lönnberg, Virpi Glumoff, Oscar Brück, Olli Dufva, Karita Peltonen, Johanna Vikkula, Emmi Jokinen, Mette Ilander, Moon Hee Lee, Siru Mäkelä, Marta Nyakas, Bin Li, Micaela Hernberg, Petri Bono, Harri Lähdesmäki, Anna Kreutzman, Satu Mustjoki
Myeloproliferative neoplasms (MPNs) are characterized by the activated JAK2-STAT pathway. Pleckstrin-2 (Plek2) is a downstream target of the JAK2-STAT pathway and overexpressed in patients with MPNs. We previously revealed that Plek2 plays critical roles in the pathogenesis of JAK2 mutated MPNs. The non-essential roles of Plek2 under physiologic conditions makes it an ideal target for MPN therapy. Here we identified first-in-class Plek2 inhibitors through an in silico high-throughput screening and cell-based assays followed by the synthesis of analogs. The Plek2 specific small molecule inhibitors showed potent inhibitory effects on cell proliferation. Mechanistically, Plek2 interacts with and enhances the activity of Akt through the recruitment of downstream effector proteins. The Plek2 signaling complex also includes Hsp72 that protects Akt from degradation. These functions were blocked by Plek2 inhibitors via their direct binding to Plek2 DEP domain. The role of Plek2 in activating the Akt signaling was further confirmed in vivo using a hematopoietic specific Pten knockout mouse model. We next tested Plek2 inhibitors alone or in combination with an Akt inhibitor in various MPN mouse models, which showed significant therapeutic efficacies similar to the genetic depletion of Plek2. The Plek2 inhibitor was also effective in reducing proliferation of CD34 positive cells from MPN patients. Our studies reveal a Plek2-Akt complex that drives cell proliferation and can be targeted by a new class of anti-proliferative compounds for MPN therapy.
Xu Han, Yang Mei, Rama K. Mishra, Honghao Bi, Atul D. Jain, Gary E. Schiltz, Baobing Zhao, Madina Sukhanova, Pan Wang, Arabela A. Grigorescu, Patricia C. Weber, John J. Piwinski, Miguel A. Prado, Joao A. Paulo, Len Stephens, Karen E. Anderson, Charles S. Abrams, Jing Yang, Peng Ji
BACKGROUND. The fungus Aspergillus fumigatus causes a variety of clinical phenotypes in patients with cystic fibrosis (pwCF). T-helper (Th) cells orchestrate immune responses against fungi, but the types of A. fumigatus-specific Th-cells in pwCF and their contribution to protective immunity or inflammation remain poorly characterized. METHODS. We used antigen-reactive T cell enrichment (ARTE) to investigate fungus-reactive Th cells in peripheral blood of pwCF and healthy controls. RESULTS. We show that clonally expanded, high-avidity A. fumigatus-specific effector Th-cells develop in pwCF, which are absent in healthy donors. Individual patients were characterized by distinct Th1, Th2, or Th17 dominated responses that remained stable over years. These different Th subsets target different A. fumigatus proteins, indicating that differential antigen uptake and presentation directs Th-cell subset development. Patients with allergic bronchopulmonary aspergillosis (ABPA) are characterized by high frequencies of Th2-cells that cross-recognize various filamentous fungi. CONCLUSION. Our data highlight the development of heterogenous Th responses targeting different protein fractions of a single fungal pathogen and identify the development of multispecies cross-reactive Th2-cells as a potential risk factor for ABPA. FUNDING. This research was supported by grants from the German Research Foundation (DFG) under Germany’s Excellence Strategy - EXC 2167-390884018 “Precision Medicine in Chronic Inflammation”, EXC 2051-390713860 “Balance of the Microverse”; the Oskar Helene Heim Stiftung; the Christiane Herzog Stiftung, Stuttgart, Germany; the Mukoviszidose Institut gGmbH, Bonn, the research and development arm of the German Cystic Fibrosis Association Mukoviszidose e.V; the German Federal Ministry of Education and Science (BMBF) InfectControl 2020 Projects AnDiPath, BMBF 03ZZ0838A+B.
Carsten Schwarz, Patience Eschenhagen, Henrijette Schmidt, Thordis Hohnstein, Christina Iwert, Claudia Grehn, Jobst Roehmel, Eva Steinke, Mirjam Stahl, Laura Lozza, Ekaterina Tikhonova, Elisa Rosati, Ulrik Stervbo, Nina Babel, Jochen G. Mainz, Hilmar Wisplinghoff, Frank Ebel, Lei-Jie Jia, Matthew G. Blango, Peter Hortschansky, Sascha Brunke, Bernhard Hube, Axel A. Brakhage, Olaf Kniemeyer, Alexander Scheffold, Petra Bacher
Tick bites have been shown to transmit a novel form of severe food allergy, the galactose-α-1,3-galactose (α-Gal) syndrome (AGS). Cellular responses to α-Gal in AGS patients have to date not been thoroughly scrutinized. Therefore, we investigated T and B cell proliferation, activation and cytokine profiles in response to tick protein extract (TE) and α-Gal-free TE in AGS patients and healthy controls. T and B cells from both patients and controls proliferated in response to TE, but significantly more in the patients. B cell proliferation, but not T cell proliferation, in AGS patients was reduced by removing α-Gal from the TE. In addition, TE induced a clear Th2 cytokine profile in AGS patients. Expression of CD23 by B cells correlated only to T cell proliferation. However, both B cell proliferation and CD23 expression were reduced when CD40L and IL-4 were blocked. A large proportion of the IgG1 and IgE antibodies binding TE in AGS patients were directed against the α-Gal epitope. We have for the first time investigated T and B cell responses to α-Gal carrying tick proteins in AGS patients, which will be essential for the understanding of the immune response against an allergenic carbohydrate transmitted by ticks.
Danijela Apostolovic, Jeanette Grundström, Mensiena B. Gea Kiewiet, Marija Perusko, Carl Hamsten, Maria H. Starkhammar, Staffan Paulie, Marianne van Hage
Microglia, resident macrophages of the central nervous system (CNS), are essential to brain development, homeostasis, and disease. Microglial activation and proliferation are hallmarks of many CNS diseases including neuropathic pain. However, molecular mechanisms that govern the spinal neuro-immune axis in the setting of neuropathic pain remain incompletely understood. Here we show that genetic ablation or pharmacological blockade of transient receptor potential vanilloid type 4 (TRPV4) markedly attenuated neuropathic pain-like behaviors in a mouse model of spared nerve injury. Mechanistically, microglia-expressed TRPV4 mediated microglial activation and proliferation and promoted functional and structural plasticity of excitatory spinal neurons through releasing lipocalin-2. Our results suggest that microglial TRPV4 channels reside at the center of the neuro-immune axis in the spinal cord that transforms peripheral nerve injury into central sensitization and neuropathic pain, thereby identifying TRPV4 as a promising new target for the treatment of chronic pain.
Xueming Hu, Lixia Du, Shenbin Liu, Zhou Lan, Kaikai Zang, Jing Feng, Yonghui Zhao, Xingliang Yang, Zili Xie, Peter L. Wang, Aaron M. Ver Heul, Lvyi Chen, Vijay K. Samineni, Yan-Qing Wang, Kory J. Lavine, Robert W. Gereau, Gregory F. Wu, Hongzhen Hu
Treatment options for Alcohol Use Disorders (AUD) have minimally advanced since 2004, while the annual deaths and economic toll have increased alarmingly. Phosphodiesterase type 4 (PDE4) is associated with alcohol and nicotine dependence. PDE4 inhibitors were identified as a potential AUD treatment using a novel bioinformatics approach. We prioritized a newer PDE4 inhibitor, apremilast, as ideal for repurposing, (i.e. FDA approved for psoriasis, low incidence of adverse events, excellent safety profile), and tested it using multiple animal strains and models, as well as in a human Phase IIa study. We found that apremilast reduced binge-like alcohol intake and behavioral measures of alcohol motivation in mouse models of genetic risk for drinking to intoxication. Apremilast also reduced excessive alcohol drinking in models for stress-facilitated drinking and alcohol dependence. Using site-directed drug infusions and electrophysiology, we uncovered that apremilast may act to lessen drinking in mice by increasing neural activity in the nucleus accumbens, a key brain region in the regulation of alcohol intake. Importantly, apremilast (90 mg/d) reduced excessive drinking in non-treatment seeking individuals with AUD in a double blind, placebo-controlled study. These results demonstrate that apremilast suppresses excessive alcohol drinking across the spectrum of AUD severity.
Kolter B. Grigsby, Regina A. Mangieri, Amanda J. Roberts, Marcelo F. Lopez, Evan J. Firsick, Kayla G. Townsley, Alan Beneze, Jessica Bess, Toby K. Eisenstein, Joseph J. Meissler, John M. Light, Jenny Miller, Susan Quello, Farhad Shadan, Michael H. Skinner, Heather C. Aziz, Pamela Metten, Richard A. Morissett, John C. Crabbe, Marisa Roberto, Howard C. Becker, Barbara J. Mason, Angela R. Ozburn
Type 2 diabetes (T2D) is caused by insufficient insulin secretion from pancreatic β-cells. To identify candidates contributing to T2D pathophysiology, we studied human pancreatic islets from ~300 individuals. We found 395 differentially expressed genes (DEGs) in islets from individuals with T2D, including, to our knowledge, novel (OPRD1, PAX5, TET1) and previously identified (CHL1, GLRA1, IAPP) candidates. A third of the identified islet expression changes may predispose to diabetes, as they associated with HbA1c in individuals not previously diagnosed with T2D. Most DEGs were expressed in human β-cells based on single-cell RNA-sequencing data. Additionally, DEGs displayed alterations in open chromatin and associated with T2D-SNPs. Mouse knock-out strains demonstrated that T2D-associated candidates regulate glucose homeostasis and body composition in vivo. Functional validation showed that mimicking T2D-associated changes for OPRD1, PAX5, and SLC2A2 impaired insulin secretion. Impairments in Pax5-overexpressing β-cells were due to severe mitochondrial dysfunction. Finally, we discovered PAX5 as a potential transcriptional regulator of many T2D-associated DEGs in human islets. Overall, we identified molecular alterations in human pancreatic islets contributing to β-cell dysfunction in T2D pathophysiology.
Karl Bacos, Alexander Perfilyev, Alexandros Karagiannopoulos, Elaine Cowan, Jones K. Ofori, Ludivine Bertonnier-Brouty, Tina Rönn, Andreas Lindqvist, Cheng Luan, Sabrina Ruhrmann, Mtakai Ngara, Åsa Nilsson, Sevda Gheibi, Claire L. Lyons, Jens O. Lagerstedt, Mohammad Barghouth, Jonathan L.S. Esguerra, Petr Volkov, Malin Fex, Hindrik Mulder, Nils Wierup, Ulrika Krus, Isabella Artner, Lena Eliasson, Rashmi B. Prasad, Luis Rodrigo Cataldo, Charlotte Ling
Christian Lacks Lino Cardenas, Lauren C. Briere, David A. Sweetser, Mark E. Lindsay, Patricia L. Musolino
The alternative sigma factor RpoS in Borrelia burgdorferi (Bb), the Lyme disease pathogen, is responsible for programmatic positive and negative gene regulation essential for the spirochete’s dual-host enzootic cycle. RpoS is expressed during tick-to-mammal transmission and throughout mammalian infection. Although the mammalian-phase RpoS regulon is well described, its counterpart during the transmission blood meal is unknown. Here, we used Bb-specific transcript enrichment by TBDCapSeq to compare the transcriptomes of wild-type and ΔrpoS Bb in engorged nymphs and following mammalian host-adaptation within dialysis membrane chambers. TBDCapSeq revealed dramatic changes in the contours of the RpoS regulon within ticks and mammals and further confirmed that RpoS-mediated repression is specific to the mammalian-phase of Bb’s enzootic cycle. We also provide evidence that RpoS-dependent gene regulation, including repression of tick-phase genes, is required for persistence in mice. Comparative transcriptomics of engineered Bb strains revealed that BosR, a non-canonical Fur family regulator, and the c-di-GMP effector PlzA reciprocally regulate RpoS function. BosR is required for RpoS-mediated transcription activation and repression in addition to its well-defined role promoting RpoN-dependent transcription of rpoS. During transmission, liganded-PlzA antagonizes RpoS-mediated repression, presumably acting through BosR.
André A. Grassmann, Rafal Tokarz, Caroline Golino, Melissa A. McLain, Ashley M. Groshong, Justin D. Radolf, Melissa J. Caimano