Mucins protect against Streptococcus pneumoniae virulence by suppressing pneumolysin expression

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Abstract

Authors

Jade Bath, Elisabet Bjånes, Cengiz Goekeri, Jeff Hsiao, Deniz Uzun, Geraldine Nouailles, Victor Nizet, Katharina Ribbeck

Modulation of NOX2 causes obesity-mediated atrial fibrillation

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Abstract

Obesity is linked to an increased risk of atrial fibrillation (AF) via increased oxidative stress. While NADPH oxidase II (NOX2), a major source of oxidative stress and reactive oxygen species (ROS) in the heart predisposes to AF, the underlying mechanisms remain unclear. Here, we studied NOX2-mediated ROS production in obesity-mediated AF using Nox2-knock-out (KO) mice and mature human induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCMs). Diet-induced obesity (DIO) mice and hiPSC-aCMs treated with palmitic acid (PA) were infused with a NOX blocker (apocynin) and a NOX2-specific inhibitor, respectively. We showed that NOX2 inhibition normalized atrial action potential duration and abrogated obesity-mediated ion channel remodeling with reduced AF burden. Unbiased transcriptomics analysis revealed that NOX2 mediates atrial remodeling in obesity-mediated AF in DIO mice, PA-treated hiPSC-aCMs, and human atrial tissue from obese individuals by upregulation of paired-like homeodomain transcription factor 2 (PITX2). Furthermore, hiPSC-aCMs treated with hydrogen peroxide, a NOX2 surrogate, displayed increased PITX2 expression, establishing a mechanistic link between increased NOX2-mediated ROS production and modulation of PITX2. Our findings offer insights into possible mechanisms through which obesity triggers AF and support NOX2 inhibition as a potential novel prophylactic or adjunctive therapy for patients with obesity-mediated AF.

Authors

Arvind Sridhar, Jaime DeSantiago, Hanna Chen, Mahmud Arif Pavel, Olivia Ly, Asia Owais, Miles Barney, Jordan Jousma, Sarath Babu Nukala, Khaled Abdelhady, Malek Massad, Lona Ernst Rizkallah, Sang-Ging Ong, Jalees Rehman, Dawood Darbar

PRMT5 mediated FUBP1 methylation accelerates prostate cancer progression

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Abstract

Strategies beyond hormone-related therapy should need to be developed to improve prostate cancer mortalityfor better disease management. Here we show that FUBP1 and its methylation are essential for prostate cancer progression, and a competitive peptide interfering with FUBP1 methylation suppresses the development of prostate cancer. FUBP1 accelerated prostate cancer development across in various pre-clinical models. PRMT5-mediated FUBP1 methylation, regulated by BRD4, was crucial for its oncogenic effect and correlated with earlier biochemical recurrence shorter treatment durations in our patient cohort. Suppressed prostate cancer progression was observed in different various genetic mouse models expressing FUBP1 mutants deficient in PRMT5-mediated methylation. A competitive peptide, which was delivered through nanocomplexes, successfully disrupted the interaction of FUBP1 with PRMT5, blocked FUBP1 methylation, and inhibited prostate cancer development in different various pre-clinical models. Overall, our findings suggest that targeting FUBP1 methylation provides a potentially therapeutic strategy for disease prostate cancer management.

Authors

Weiwei Yan, Xun Liu, Xuefeng Qiu, Xuebin Zhang, Jiahui Chen, Kai Xiao, Ping Wu, Chao Peng, Xiaolin Hu, Zengming Wang, Jun Qin, Liming Sun, Luonan Chen, Denglong Wu, Shengsong Huang, Lichen Yin, Zhenfei Li

TET3-overexpressing macrophages promote endometriosis

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Endometriosis is a debilitating, chronic inflammatory disease affecting ~10% of reproductive age women worldwide with no cure. While macrophages have been intrinsically linked to the pathophysiology of endometriosis, targeting them therapeutically has been extremely challenging due to their high heterogeneity and because these disease-associated macrophages (DAMs) can be either pathogenic or protective. Here, we reported identification of pathogenic macrophages characterized by TET3 overexpression in human endometriosis lesions. We showed that factors from the disease microenvironment upregulated TET3 expression transforming macrophages into pathogenic DAMs. TET3 overexpression stimulated pro-inflammatory cytokine production via a feedback mechanism involving inhibition of let-7 miRNA expression. Remarkably, these cells relied on TET3 overexpression for survival, hence vulnerable to TET3 knockdown. We demonstrated that Bobcat339, a synthetic cytosine derivative, triggered TET3 degradation both in human and mouse macrophages. This degradation was dependent on a VHL E3 ubiquitin ligase whose expression was also upregulated in TET3-overexpressing macrophages. Furthermore, depleting TET3-overexpressing macrophages either through myeloid-specific Tet3 ablation or using Bobcat339 strongly inhibited endometriosis progression in mice. Our results defined TET3-overexpressing macrophages as key pathogenic contributors to and attractive therapeutic targets for endometriosis. Our findings may also be applicable to other chronic inflammatory diseases where DAMs have important roles.

Authors

Haining Lv, Beibei Liu, Yangyang Dai, Feng Li, Stefania Bellone, Yuping Zhou, Ramanaiah Mamillapalli, Dejian Zhao, Muthukumaran Venkatachalapathy, Yali Hu, Gordon G. Carmichael, Da Li, Hugh S. Taylor, Yingqun Huang

Pediatric glioma immune profiling identifies TIM3 as a therapeutic target in BRAF-Fusion pilocytic astrocytoma

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Abstract

Despite being the leading cause of childhood mortality, pediatric gliomas have been relatively understudied, and the repurposing of immunotherapies has not been successful. Whole transcriptome sequencing, single-cell sequencing, and sequential multiplex immunofluorescence were used to identify an immunotherapy strategy evaluated in multiple preclinical glioma models. MAPK-driven pediatric gliomas have a higher interferon signature relative to other molecular subgroups. Single-cell sequencing identified an activated and cytotoxic microglia population designated MG-Act in BRAF-fused MAPK-activated pilocytic astrocytoma (PA), but not in high-grade gliomas or normal brain. TIM3 is expressed on MG-Act and on the myeloid cells lining the tumor vasculature but not normal brain. TIM3 expression becomes upregulated on immune cells in the PA microenvironment and anti-TIM3 reprograms ex vivo immune cells from human PAs to a pro-inflammatory cytotoxic phenotype. In a genetically engineered murine model of MAPK-driven low-grade gliomas, anti-TIM3 treatment increased median survival over IgG and anti-PD1 treated mice. ScRNA sequencing data during the therapeutic window of anti-TIM3 demonstrates enrichment of the MG-Act population. The therapeutic activity of anti-TIM3 is abrogated in the CX3CR1 microglia knockout background. These data support the use of anti-TIM3 in clinical trials of pediatric low-grade MAPK-driven gliomas.

Authors

Shashwat Tripathi, Hinda Najem, Corey Dussold, Sebastian Pacheco, Ruochen Du, Moloud Sooreshjani, Lisa A. Hurley, James P. Chandler, Roger Stupp, Adam M. Sonabend, Craig M. Horbinski, Rimas V. Lukas, Joanne Xiu, Giselle Y. López, Theodore P. Nicolaides, Valerie Brown, Nitin R. Wadhwani, Sandi K. Lam, Charles David James, Ganesh Rao, Maria G. Castro, Amy B. Heimberger, Michael DeCuypere

Teplizumab induces persistent changes in the antigen‐specific repertoire in individuals at‐risk for type 1 diabetes

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Abstract

BACKGROUND. Teplizumab, a FcR non-binding anti-CD3 mAb, is approved to delay progression of type 1 diabetes (T1D) at-risk patients. Previous investigations described the immediate effects of the 14-day treatment, but longer-term effects of the drug remain unknown. METHODS. With an extended analysis of study participants, we found that 36% were undiagnosed or remained clinical diabetes free after 5 years suggesting operational tolerance. Using single cell RNA-seq, we compared the phenotypes, transcriptome, and repertoire of peripheral blood CD8+ T cells including autoreactive T cells from study participants before and after teplizumab and features of responders and non-responders. RESULTS. At 3 months, there were transcriptional signatures of cell activation in CD4+ and CD8+ T cells including signaling that was reversed at 18 months. At that time, there was reduced expression of genes in T cell receptor and activation pathways in clinical responders. In CD8+ T cells, we found increased expression of genes associated with exhaustion and immune regulation with teplizumab treatment. These transcriptional features were further confirmed in an independent cohort. Pseudotime analysis showed differentiation of CD8+ exhausted and memory cells with teplizumab treatment. IL7R expression was reduced and patients with lower expression of CD127 had longer diabetes free intervals. In addition, the frequency of autoantigen reactive CD8+ T cells, that expanded in the placebo group over 18 months, did not increase in the teplizumab group. CONCLUSION. These findings indicate that teplizumab promotes operational tolerance in T1D, involving activation followed by exhaustion and regulation and prevents expansion of autoreactive T cells. TRIAL REGISTRATION. ClinicalTrials.gov: NCT01030861. FUNDING. NIDDK/NIH, Juvenile Diabetes Research Foundation.

Authors

Ana Lledó-Delgado, Paula Preston-Hurlburt, Sophia Currie, Pamela Clark, Peter S. Linsley, S. Alice Long, Can Liu, Galina Koroleva, Andrew J. Martins, John S. Tsang, Kevan C. Herold

Central regulation of feeding and body weight by ciliary GPR75

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Variants of the G protein-coupled receptor 75 (GPR75) are associated with lower BMI in large-scale human exome sequencing studies. However, how GPR75 regulates body weight remains poorly understood. Using random germline mutagenesis in mice, we identified a missense allele (Thinner) of Gpr75 that resulted in a lean phenotype and verified the decreased body weight and fat weight in Gpr75 knockout (Gpr75–/–) mice. Gpr75–/– mice displayed reduced food intake under a high-fat diet (HFD), and pair-feeding normalized their body weight. The endogenous GPR75 protein was exclusively expressed in the brains of 3xFlag tagged Gpr75 knock-in (3xFlag-Gpr75) mice, with consistent expression across different brain regions. GPR75 interacted with Gαq to activate various signaling pathways after HFD feeding. Additionally, GPR75 was localized in the primary cilia of hypothalamic cells, whereas the Thinner mutation (L144P) and human GPR75 variants with lower BMI failed to localize in the cilia. Loss of GPR75 selectively inhibited weight gain in HFD-fed mice but failed to suppress the development of obesity in Leptin ob mice and Adenylate cyclase 3 (Adcy3) mutant mice on a chow diet. Our data reveal that GPR75 is a ciliary protein expressed in the brain and plays an important role in regulating food intake.

Authors

Yiao Jiang, Yu Xun, Zhao Zhang

F¹⁸-FDG PET imaging as a diagnostic tool for immune checkpoint inhibitor-associated acute kidney injury

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Abstract

Authors

Shruti Gupta, Olivia Green-Lingren, Sudhir Bhimaniya, Aleksandra Krokhmal, Heather Jacene, Marlies Ostermann, Sugama Chicklore, Ben Sprangers, Christophe M. Deroose, Sandra M. Herrmann, Sophia L. Wells, Sarah A. Kaunfer, Jessica L. Ortega, Clara Garcia-Carro, Michael Bold, Kevin L. Chen, Meghan E. Sise, Pedram Heidari, Wai Lun Will Pak, Meghan D. Lee, Pazit Beckerman, Yael Eshet, Raymond K. Hsu, Miguel Hernandez Pampaloni, Arash Rashidi, Norbert Avril, Vicki Donley, Zain Mithani, Russ Kuker, Muhammad O Awiwi, Mindy X. Wang, Sujal I. Shah, Michael D. Weintraub, Heiko Schoder, Raad B. Chowdhury, Harish Seethapathy, Kerry L. Reynolds, Maria Jose Soler, Ala Abudayyeh, Ilya Glezerman, David E. Leaf

Hif-2α programmes oxygen chemosensitivity in chromaffin cells

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The study of transcription factors that determine specialised neuronal functions has provided invaluable insights into the physiology of the nervous system. Peripheral chemoreceptors are neurone-like electro-physiologically excitable cells that link the oxygen content of arterial blood to the neuronal control of breathing. In the adult, this oxygen chemosensitivity is exemplified by the Type I cells of the carotid body and recent work has revealed one isoform of the transcription factor HIF, HIF-2α, to have a non-redundant role in the development and function of that organ. Here we show that the activation of HIF-2α, including isolated overexpression alone, is sufficient to induce oxygen chemosensitivity in the otherwise unresponsive adult adrenal medulla. This phenotypic change in the adrenal medulla was associated with retention of extra-adrenal paraganglioma-like tissues that resemble the foetal organ of Zuckerkandl and also manifest oxygen chemosensitivity. Acquisition of chemosensitivity was associated with changes in the adrenal medullary expression of classes of genes that are ordinarily characteristic of the carotid body, including G-protein regulators and atypical subunits of mitochondrial cytochrome oxidase. Overall, the findings suggest that, at least in certain tissues, HIF-2α acts as a phenotypic driver for cells that display oxygen chemosensitivity, thus linking two major oxygen sensing systems.

Authors

Maria Prange-Barczynska, Holly A. Jones, Yoichiro Sugimoto, Xiaotong Cheng, Joanna D.C.C Lima, Indrika Ratnayaka, Gillian Douglas, Keith J. Buckler, Peter J. Ratcliffe, Thomas P. Keeley, Tammie Bishop

NKT cells promote Th1 immune bias to dengue virus that governs long term protective antibody dynamics

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NKT cells are innate-like T cells, recruited to the skin during viral infection, yet their contributions to long-term immune memory to viruses are unclear. We identified granzyme K, a product made by cytotoxic cells including NKT cells, is linked to induction of Th1-associated antibodies during primary dengue virus (DENV) infection in humans. We examined the role of NKT cells in vivo using DENV-infected mice lacking CD1d-dependent (CD1ddep) NKT cells. In CD1d-KO mice, Th1-polarized immunity and infection resolution were impaired, which was dependent on intrinsic NKT cell production of IFN-γ, since it was restored by adoptive transfer of WT but not IFN-γ-KO NKT cells. Furthermore, NKT cell deficiency triggered immune bias, resulting in higher levels of Th2-associated IgG1 than Th1-associated IgG2a, which failed to protect against a homologous DENV re-challenge and promoted antibody-dependent enhanced disease during secondary heterologous infections. Similarly, Th2-immunity, typified by a higher IgG4:IgG3 ratio, was associated with worsened human disease severity during secondary infections. Thus, CD1ddep NKT cells establish Th1 polarity during the early innate response to DENV, which promotes infection resolution, memory formation and long-term protection from secondary homologous and heterologous infections. These observations illustrate how early innate immune responses during primary infections can influence secondary infection outcomes.

Authors

Youngjoo Choi, Wilfried A.A. Saron, Aled O'Neill, Manouri Senanayake, Annelies Wilder-Smith, Abhay P.S. Rathore, Ashley L. St. John