Genetic defects of GNAS, the imprinted gene encoding the stimulatory G protein α-subunit, are responsible for multiple diseases. Abnormal GNAS imprinting causes pseudohypoparathyroidism type 1B (PHP1B), a prototype of mammalian end-organ hormone resistance. Hypomethylation at the maternally methylated GNAS A/B region is the only shared defect in PHP1B patients. In autosomal dominant (AD) PHP1B kindreds, A/B hypomethylation is associated with maternal microdeletions at either the GNAS NESP55 differentially methylated region or the STX16 gene located ~170 kb upstream. Functional evidence is meager regarding the causality of these microdeletions. Moreover, the mechanisms linking A/B methylation and these putative imprinting control regions (ICRs), NESP-ICR and STX16-ICR, remain unknown. Here, we generated a human embryonic stem cell model of AD-PHP1B by introducing ICR deletions using CRISPR/Cas9. Using this model, we showed that NESP-ICR is required for methylation and transcriptional silencing of A/B on the maternal allele. We also found that SXT16-ICR is a long-range enhancer of NESP55 transcription, which originates from maternal NESP-ICR. Furthermore, we demonstrated that STX16-ICR is an embryonic stage-specific enhancer enabled by the direct binding of pluripotency factors. Our findings uncover an essential GNAS imprinting control mechanism and advance the molecular understanding of the PHP1B pathogenesis.
Yorihiro Iwasaki, Cagri Aksu, Monica Reyes, Birol Ay, Qing He, Murat Bastepe
Multiple Sclerosis (MS) is a complex disease of the CNS thought to require an environmental trigger. Gut dysbiosis is common in MS, but specifically causative species are unknown. To address this knowledge gap, we used sensitive and quantitative PCR detection to show that people with MS were more likely to harbor and show a greater abundance of epsilon toxin (ETX)-producing strains of C. perfringens within their gut microbiomes compared to healthy controls (HC). MS patient-derived isolates produced functional ETX and had a genetic architecture typical of highly conjugative plasmids. In the active immunization model of experimental autoimmune encephalomyelitis (EAE), where pertussis toxin (PTX) is used to overcome CNS immune privilege, ETX can substitute for PTX. In contrast to PTX-induced EAE, where inflammatory demyelination is largely restricted to the spinal cord, ETX-induced EAE caused demyelination in the corpus callosum, thalamus, cerebellum, brainstem, and spinal cord, more akin to the neuroanatomical lesion distribution in MS. CNS endothelial cell transcriptional profiles revealed ETX-induced genes that are known to play a role in overcoming CNS immune privilege. Together, these findings suggest that ETX-producing C. perfringens strains are biologically plausible pathogens in MS that trigger inflammatory demyelination in the context of circulating myelin autoreactive lymphocytes.
Yinghua Ma, David Sannino, Jennifer R. Linden, Sylvia Haigh, Baohua Zhao, John B. Grigg, Paul Zumbo, Friederike Dündar, Daniel J. Butler, Caterina P. Profaci, Kiel M. Telesford, Paige N. Winokur, Kareem R. Rumah, Susan A. Gauthier, Vincent A. Fischetti, Bruce A. McClane, Francisco A. Uzal, Lily Zexter, Michael Mazzucco, Richard Rudick, David Danko, Evan Balmuth, Nancy Nealon, Jai Perumal, Ulrike W. Kaunzner, Ilana L. Brito, Zhengming Chen, Jenny Z. Xiang, Doron Betel, Richard Daneman, Gregory F. Sonnenberg, Christopher E. Mason, Timothy Vartanian
CD8+ exhausted T-cells (Tex) are heterogeneous. PD-1 inhibitors reinvigorate progenitor Tex, which subsequently differentiate into irresponsive terminal Tex. Maintaining durable proliferative capacity of progenitor Tex is important but remains unclear. Here, we showed that low-dose DNA demethylating agent decitabine-pretreated CD8+ progenitor Tex had enhanced proliferation and effector function against tumors after anti-PD-1 treatment in vitro. Decitabine-plus-anti-PD-1 treatment promoted the activation and expansion of tumor-infiltrated CD8+ progenitor Tex and efficiently suppressed tumor growth in multiple tumor models. Transcriptional and epigenetic profiling of tumor-infiltrated T cells demonstrated that decitabine-plus-anti-PD-1 combination markedly elevated the clonally expansion and cytolytic activity of progenitor Tex compared with anti-PD-1 monotherapy and restrained CD8+ T-cell terminal differentiation. Strikingly, decitabine-plus-anti-PD-1 sustained the expression and activity of AP-1 transcription factor JunD, which was reduced following PD-1 blockade therapy. Downregulation of JunD repressed T cell proliferation and activating JNK/AP-1 signaling in CD8+ T-cells enhanced the antitumor capacity of PD-1 inhibitors. Together, epigenetic agent remodels CD8+ progenitor Tex and improves responsiveness to anti-PD-1 therapy.
Xiang Li, Yaru Li, Liang Dong, Yixin Chang, Xingying Zhang, Chunmeng Wang, Meixia Chen, Xiaochen Bo, Hebing Chen, Weidong Han, Jing Nie
Activation of STING signaling in dendritic cells (DCs) promotes antitumor immunity. Aerobic glycolysis is a metabolic hallmark of activated DCs, but how the glycolytic pathway intersects with STING signaling in tumor-infiltrating DCs remains elusive. Here, we show that glycolysis drives STING signaling to facilitate DC-mediated antitumor immune responses. Tumor-infiltrating DCs exhibited elevated glycolysis, and blockade of glycolysis by DC-specific Ldha/Ldhb double deletion resulted in defective antitumor immunity. Mechanistically, glycolysis augmented ATP production to boost STING activation and STING-dependent DC antitumor functions. Moreover, DC-intrinsic STING activation accelerated HIF-1a–mediated glycolysis and established a positive feedback loop. Importantly, glycolysis facilitated STING-dependent DC activity in tissue samples from non-small cell lung cancer patients. Our results provide mechanistic insight into how the crosstalk of glycolytic metabolism and STING signaling enhances DC antitumor activity and can be harnessed to improve cancer therapies.
Zhilin Hu, Xiaoyan Yu, Rui Ding, Ben Liu, Chuanjia Gu, Xiu-Wu Pan, Qiaoqiao Han, Yuerong Zhang, Jie Wan, Xin-gang Cui, Jiayuan Sun, Qiang Zou
Lorenza Bellusci, Hana Golding, Surender Khurana
Liver metastasis represents one of the most frequent malignant diseases with no effective treatment. As the largest population of hepatic macrophages, functional reprogramming of Kupffer cells (KCs) holds promise for treating liver cancer but remains seldom exploited. Taking advantage of the superior capacity of KCs to capture circulating bacteria, we report that a single administration of attenuated Escherichia coli producing CRISPR‒CasΦ machinery enables efficient editing of genes of interest in KCs. Using intravital microscopy, we observed a failure of tumor control by KCs at the late stage of liver metastasis due to KC loss preferentially in the tumor core and periphery, resulting in inaccessibility of these highly phagocytic macrophages to cancer cells. Simultaneous disruption of MafB and c-Maf expression using the aforementioned engineered bacteria could overcome KC dysfunction and elicit remarkable curative effects against several types of metastatic liver cancer in mice. Mechanistically, bacterial treatment induced massive proliferation and functional reprogramming of KCs. These cells infiltrated into the tumor, dismantled macrometastases by nibbling cancer cells, and skewed toward proinflammatory macrophages to unleash antitumor T-cell responses. These findings provide an immunotherapy strategy that could be applicable for treating liver metastasis and highlight the therapeutic potential of targeting tissue-resident macrophages in cancer.
Wei Liu, Xia Zhou, Qi Yao, Chen Chen, Qing Zhang, Keshuo Ding, Lu Li, Zhutian Zeng
How phosphate levels are detected in mammals is unknown. The bone-derived hormone fibroblast growth factor 23 (FGF23) lowers blood phosphate by reducing kidney phosphate reabsorption and 1,25(OH)2D production, but phosphate does not directly stimulate bone FGF23 expression. Using PET scanning and LC-MS, we show that phosphate increases kidney-specific glycolysis and synthesis of glycerol-3-phosphate (G-3-P), which then circulates to bone to trigger FGF23 production. Further, we find that glycerol-3-phosphate dehydrogenase 1 (Gpd1), a cytosolic enzyme that synthesizes G-3-P and oxidizes NADH to NAD+, is required for phosphate-stimulated G-3-P and FGF23 production and prevention of hyperphosphatemia. In proximal tubule cells, we find that phosphate availability is substrate-limiting for glycolysis and G-3-P production, and that increased glycolysis and Gpd1 activity are coupled through cytosolic NAD+ recycling. Finally, we show that the type II sodium-dependent phosphate co-transporter Npt2a, which is expressed exclusively in the proximal tubule, confers kidney specificity to phosphate-stimulated G-3-P production. Importantly, exogenous G-3-P stimulates FGF23 production when Npt2a or Gpd1 are absent, confirming that it is the key circulating factor downstream of glycolytic phosphate sensing in the kidney. Together, these findings place glycolysis at the nexus of mineral and energy metabolism and identify a kidney-bone feedback loop that controls phosphate homeostasis.
Wen Zhou, Petra Simic, Iris Y. Zhou, Peter Caravan, Xavier Vela Parada, Donghai Wen, Onica L. Washington, Maria Shvedova, Kerry A. Pierce, Clary B. Clish, Michael Mannstadt, Tatsuya Kobayashi, Marc N. Wein, Harald Jüppner, Eugene P. Rhee
Adaptation of the islet β-cell insulin secretory response to changing insulin demand is critical for blood glucose homeostasis, yet the mechanisms underlying this adaptation are unknown. Here, we have shown that nutrient-stimulated histone acetylation plays a key role in adapting insulin secretion through regulation of genes involved in β-cell nutrient sensing and metabolism. Nutrient regulation of the epigenome occurred at sites occupied by the chromatin-modifying enzyme Lysine-specific demethylase 1 (Lsd1) in islets. β-cell-specific deletion of Lsd1 led to insulin hypersecretion, aberrant expression of nutrient response genes, and histone hyperacetylation. Islets from mice adapted to chronically increased insulin demand exhibited shared epigenetic and transcriptional changes. Moreover, we found that genetic variants associated with type 2 diabetes were enriched at LSD1-bound sites in human islets, suggesting that interpretation of nutrient signals is genetically determined and clinically relevant. Overall, these studies revealed that adaptive insulin secretion involves Lsd1-mediated coupling of nutrient state to regulation of the islet epigenome.
Matthew Wortham, Fenfen Liu, Austin R. Harrington, Johanna Y. Fleischman, Martina Wallace, Francesca Mulas, Medhavi Mallick, Nicholas K. Vinckier, Benjamin R. Cross, Joshua Chiou, Nisha A. Patel, Yinghui Sui, Carolyn McGrail, Yesl Jun, Gaowei Wang, Ulupi S. Jhala, Roland Schüle, Orian S. Shirihai, Mark O. Huising, Kyle J. Gaulton, Christian M. Metallo, Maike Sander
Calmodulin (CaM) plays critical roles in cardiomyocytes, regulating Na+ (NaV) and L-type Ca2+ channels (LTCC). LTCC dysregulation by mutant CaMs has been implicated in action potential duration (APD) prolongation and arrhythmogenic long QT (LQT) syndrome. Intriguingly, D96V-CaM prolongs APD more than other LQT-associated CaMs despite inducing comparable levels of LTCC dysfunction, suggesting dysregulation of other depolarizing channels. Here, we provide evidence implicating NaV dysregulation within transverse (T)-tubules in D96V-CaM-associated arrhythmias. D96V-CaM induces pro-arrhythmic late Na+ current (INa) by impairing inactivation of NaV1.6, but not the predominant cardiac NaV isoform, NaV1.5. We investigated arrhythmia mechanisms using mice with cardiac-specific expression of D96V-CaM (cD96V). Super-resolution microscopy revealed close proximity of NaV1.6 and RyR2 within T-tubules. NaV1.6 density within these regions increased in cD96V relative to WT. Consistent with NaV1.6 dysregulation by D96V-CaM in these regions, we observed increased late NaV activity in T-tubules. The resulting late INa promoted aberrant Ca2+ release and prolonged APD in myocytes, leading to LQT and ventricular tachycardia (VT) in vivo. Cardiac-specific NaV1.6 knockout protected cD96V mice from increased T-tubular late NaV activity, and its arrhythmogenic consequences. In summary, we demonstrate that D96V-CaM promotes arrhythmias by dysregulating LTCC and NaV1.6 within T-tubules and thereby, facilitating aberrant Ca2+ release.
Mikhail Tarasov, Heather L. Struckman, Yusuf Olgar, Alec Miller, Mustafa Demirtas, Vladimir Bogdanov, Radmila Terentyeva, Andrew M. Soltisz, Xiaolei Meng, Dennison Min, Galina Sakuta, Izabella Dunlap, Antonia D. Duran, Mark P. Foster, Jonathan P. Davis, Dmitry Terentyev, Sándor Györke, Rengasayee Veeraraghavan, Przemysław B. Radwański
Alice E. Hughes, Elisa De Franco, Rachel M. Freathy, Sarah E. Flanagan, Andrew T. Hattersley
Clearance of senescent cells (SnCs) can prevent several age-related pathologies, including bone loss. However, the local versus systemic roles of SnCs in mediating tissue dysfunction remain unclear. Thus, we developed a mouse model (p16-LOX-ATTAC) that allows for inducible SnC elimination (senolysis) in a cell-specific manner and compared the effects of local versus systemic senolysis during aging using bone as a prototype tissue. Specific removal of Sn osteocytes prevented age-related bone loss at the spine, but not the femur, by improving bone formation without affecting osteoclasts or marrow adipocytes. By contrast, systemic senolysis prevented bone loss at the spine and femur and not only improved bone formation, but also reduced osteoclasts and marrow adipocytes. Transplantation of SnCs into the peritoneal cavity of young mice caused bone loss and also induced senescence in distant host osteocytes. Collectively, our findings provide the first proof-of-concept evidence that local senolysis has health benefits in the context of aging, but importantly, local senolysis only partially replicates the benefits of systemic senolysis. Further, we establish that SnCs, through their SASP, lead to senescence in distant cells. Therefore, our study indicates that optimizing senolytic drugs may require systemic instead of local SnC targeting to extend healthy aging.
Joshua N. Farr, Dominik Saul, Madison L. Doolittle, Japneet Kaur, Jennifer L. Rowsey, Stephanie J. Vos, Mitchell N. Froemming, Anthony B. Lagnado, Yi Zhu, Megan M. Weivoda, Yuji Ikeno, Robert J. Pignolo, Laura J. Niedernhofer, Paul D. Robbins, Diana Jurk, João F. Passos, Nathan K. LeBrasseur, Tamara Tchkonia, James L. Kirkland, David G. Monroe, Sundeep Khosla
Although certain human genetic variants are conspicuously loss-of-function, decoding the impact of many variants is challenging. Previously, we described a leukemia predisposition syndrome (GATA2-deficiency) patient with a germline GATA2 variant that inserts nine amino acids between the two zinc fingers (9aa-Ins). Here, we conducted mechanistic analyses using genomic technologies and a genetic rescue system with Gata2 enhancer-mutant hematopoietic progenitor cells to compare how GATA2 and 9aa-Ins function genome-wide. Despite nuclear localization, 9aa-Ins was severely defective in occupying and remodeling chromatin and regulating transcription. Variation of the inter-zinc finger spacer length revealed that insertions were more deleterious to activation than repression. GATA2-deficiency generated a lineage-diverting gene expression program and a hematopoiesis-disrupting signaling network in progenitors with reduced Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) and elevated Interleukin-6 (IL-6) signaling. As insufficient GM-CSF signaling causes pulmonary alveolar proteinosis and excessive IL-6 signaling promotes bone marrow failure, GATA2-deficiency patient phenotypes, these results inform mechanisms underlying GATA2-linked pathologies.
Mabel Minji Jung, Siqi Shen, Giovanni A. Botten, Thomas Olender, Koichi R. Katsumura, Kirby D. Johnson, Alexandra A. Soukup, Peng Liu, Qingzhou Zhang, Zena D. Jensvold, Peter W. Lewis, Robert A. Beagrie, Jason K.K. Low, Lihua Yang, Joel P. Mackay, Lucy A. Godley, Marjorie Brand, Jian Xu, Sunduz Keles, Emery H. Bresnick
Activation of the tyrosine kinase c-Src promotes breast cancer progression and poor outcomes, yet the underlying mechanisms are incompletely understood. Here, we show that deleting c-Src abrogates the activity of Forkhead Box M1 (FOXM1), a master transcriptional regulator of the cell cycle, in a genetically engineered model mimicking the Luminal B molecular subtype of breast cancer. By phosphorylating it on two tyrosine residues, c-Src stimulates the nuclear localization of FOXM1 and the expression of its target genes, including key regulators of G2-M cell cycle progression as well as c-Src itself. This positive feedback loop drives proliferation in genetically engineered and patient-derived models of Luminal B-like breast cancer. Targeting this mechanism, including through novel compounds that destabilize the FOXM1 protein, induces G2-M cell cycle arrest and apoptosis, blocking tumor progression and impairing metastasis. We identify a positive correlation between FOXM1 and c-Src expression in human breast cancer and show that the expression of FOXM1 target genes predicts poor outcomes and associates with the Luminal B subtype, which responds poorly to approved therapies. These findings indicate that a regulatory network centered on c-Src and FOXM1 is a targetable vulnerability in aggressive luminal breast cancers.
Ipshita Nandi, Harvey W. Smith, Virginie Sanguin-Gendreau, Linjia Ji, Alain Pacis, Vasilios Papavasiliou, Dongmei Zuo, Stella Nam, Sherif S. Attalla, Sung Hoon Kim, Sierra Lusson, Hellen Kuasne, Anne-Marie Fortier, Paul Savage, Constanza Martinez Ramirez, Morag Park, John A. Katzenellenbogen, Benita S. Katzenellenbogen, William J. Muller
Lysosomal inhibition elicited by palmitoyl protein transferase 1 (PPT1) inhibitors such as DC661 can produce cell death, but the mechanism is not completely understood. Programmed cell death pathways (autophagy, apoptosis, necroptosis, ferroptosis, and pyroptosis) were not required to achieve the cytotoxic effect of DC661. Inhibition of cathepsins, or iron or calcium chelation, did not rescue DC661-induced cytotoxicity. PPT1 inhibition induced lysosomal lipid peroxidation (LLP), which led to lysosomal membrane permeabilization and cell death that could be reversed by the antioxidant N-acetylcysteine (NAC), but not by other lipid peroxidation antioxidants. The lysosomal cysteine transporter MFSD12, was required for intralysosomal transport of NAC and rescue of LLP. PPT1 inhibition produced cell-intrinsic immunogenicity with surface expression of calreticulin that could only be reversed with NAC. DC661-treated cells primed naïve T cells, and enhanced T cell-mediated toxicity. Mice vaccinated with DC661-treated cells, engendered adaptive immunity and tumor rejection in “immune hot” tumors but not in “immune cold” tumors. These findings demonstrate LLP drives lysosomal cell death, a unique immunogenic form of cell death, pointing the way to rational combinations of immunotherapy and lysosomal inhibition that can be tested in clinical trials.
Monika Bhardwaj, Jennifer J. Lee, Amanda M. Versace, Sandra L. Harper, Aaron R. Goldman, Mary Ann S. Crissey, Vaibhav Jain, Mahendra Pal Singh, Megane Vernon, Andrew E. Aplin, Seokwoo Lee, Masao Morita, Jeffrey D. Winkler, Qin Liu, David W. Speicher, Ravi K. Amaravadi
Although protein hydroxylation is a relatively poorly characterized post-translational modification, it has received significant recent attention following seminal work uncovering its role in oxygen sensing and hypoxia biology. Although the fundamental importance of protein hydroxylases in biology is becoming clear, the biochemical targets and cellular functions often remain enigmatic. JMJD5 is a ‘JmjC-only’ protein hydroxylase that is essential for murine embryonic development and viability. However, no germline variants in JmjC-only hydroxylases, including JMJD5, have yet been described that are associated with any human pathology. Here we demonstrate that biallelic germline JMJD5 pathogenic variants are deleterious to JMJD5 mRNA splicing, protein stability, and hydroxylase activity, resulting in a human developmental disorder characterised by severe failure to thrive, intellectual disability, and facial dysmorphism. We show that the underlying cellular phenotype is associated with increased DNA replication stress and that this is critically dependent on the protein hydroxylase activity of JMJD5. This work contributes to our growing understanding of the role and importance of protein hydroxylases in human development and disease.
Sally C. Fletcher, Charlotte L. Hall, Tristan J. Kennedy, Sander Pajusalu, Monica H. Wojcik, Uncaar Boora, Chan Li, Kaisa Teele Oja, Eline Hendrix, Christian A.E. Westrip, Regina Andrijes, Sonia K. Piasecka, Mansi Singh, Mohammed E. El-Asrag, Anetta Ptasinska, Vallo Tillmann, Martin R. Higgs, Deanna Alexis Carere, Andrew D. Beggs, John Pappas, Rachel Rabin, Stephen J. Smerdon, Grant S. Stewart, Katrin Õunap, Mathew L. Coleman
Glucose homeostasis can be improved after bariatric surgery that alters bile flow and stimulate gut hormone secretion, in particular FGF15/19. FGFR1 expression in AGRP expressing cells is required for bile acids's ability to improve glucose control. We show that the mouse Agrp gene has 3 promoter/enhancer regions that direct transcription of each of their own AGRP transcripts. One of these Agrp promoters/enhancers, Agrp B, is regulated by bile acids. We generated an Agrp B knock-in FLP/knockout allele. AGRP B expressing cells are found in endocrine cells the pars tuberalis (PT) and co-expressDAGLB (an endocannabinoid biosynthetic enzyme), distinct from PT thyrotropes. AGRP B expression is also found in the folliculostellate cells of the pituitary's anterior lobe. Mice without AGRP B are protected from high fat feeding induced glucose intolerance but not excess weight gain. Chemogenetic inhibition of AGRP B cells improves glucose tolerance by enhancing glucose stimulated insulin secretion. Inhibition of the AGRP B cells also caused weight loss. The improved glucose tolerance and reduced body weight persisted up to 6 weeks after cessation of the DREADD mediated inhibition, suggesting the presence of a biological switch for glucose homeostasis that is regulated by long term stability of food availability.
Shun-Mei Liu, Bruno Ifebi, Fred Johnson III, Alison Xu, Jacquelin Ho, Yunlei Yang, Gary J. Schwartz, Young-Hwan Jo, Streamson Chua
STING-Type I interferon (IFN) signaling in myeloid cells plays a critical role in effective antitumor immune responses, but STING agonist as monotherapy has shown limited efficacy in clinical trials. The mechanisms that downregulate STING signaling are not fully understood. Here, we report that Protein phosphatase 2A (PP2A) with its specific B regulatory subunit STRN4 negatively regulated STING-Type I IFN in macrophages. Mice with macrophages PP2A deficiency exhibited reduced tumor progression. The tumor microenvironment showed decreased immunosuppressive and increased IFN-activated macrophages and CD8+ T cells. Mechanistically, we demonstrated that hippo kinase MST1/2 was required for STING activation. STING agonist induced dissociation of PP2A from MST1/2 in normal macrophages, but not in tumor conditioned macrophages. Furthermore, our data showed that STRN4 mediated PP2A binding to and dephosphorylation of hippo kinase MST1/2, resulting in stabilization of YAP/TAZ to antagonize STING activation. In human GBM patients, YAP/TAZ was highly expressed in tumor-associated macrophages but not in non-tumor macrophages. We also demonstrated that PP2A/STRN4 deficiency in macrophages reduced YAP/TAZ expression and sensitized tumor conditioned macrophages to STING stimulation. In summary, we demonstrated that PP2A/STRN4-YAP/TAZ is a previously unappreciated mechanism that mediate immunosuppression in tumor-associated macrophages and targeting PP2A/STRN4-YAP/TAZ axis can sensitize tumors to immunotherapy.
Winson S. Ho, Isha Mondal, Beisi Xu, Oishika Das, Raymond C. Sun, Pochin Chiou, Xiaomin Cai, Foozhan Tahmasebinia, Caren Yu-Ju Wu, Zhihao Wu, William Matsui, Michael Lim, Zhipeng Meng, Rongze Olivia Lu
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