Enhanced de novo lipogenesis mediated by sterol regulatory element-binding proteins (SREBPs) is thought to be involved in nonalcoholic steatohepatitis (NASH) pathogenesis. In this study, we assessed the impact of SREBP inhibition on NASH and liver cancer development in murine models. Unexpectedly, SREBP inhibition via deletion of the SREBP cleavage-activating protein (SCAP) in the liver exacerbated liver injury, fibrosis, and carcinogenesis, despite markedly reduced hepatic steatosis. These phenotypes were ameliorated by restoring SREBP function. Transcriptome and lipidome analyses revealed that SCAP–SREBP pathway inhibition altered the fatty acid (FA) composition of phosphatidylcholines due to both impaired FA synthesis and disorganized FA incorporation into phosphatidylcholine via lysophosphatidylcholine acyltransferase 3 (LPCAT3) downregulation, which led to endoplasmic reticulum (ER) stress and hepatocyte injury. Supplementation of phosphatidylcholines significantly improved liver injury and ER stress induced by SCAP deletion. The activity of SCAP-SREBP-LPCAT3 axis was found inversely associated with liver fibrosis severity in human NASH. SREBP inhibition also cooperated with impaired autophagy to trigger liver injury. Thus, excessively strong and broad lipogenesis inhibition was counterproductive for NASH therapy, which will have important clinical implications in NASH treatment.
Satoshi Kawamura, Yuki Matsushita, Shigeyuki Kurosaki, Mizuki Tange, Naoto Fujiwara, Yuki Hayata, Yoku Hayakawa, Nobumi Suzuki, Masahiro Hata, Mayo Tsuboi, Takahiro Kishikawa, Hiroto Kinoshita, Takuma Nakatsuka, Masaya Sato, Yotaro Kudo, Yujin Hoshida, Atsushi Umemura, Akiko Eguchi, Tsuneo Ikenoue, Yoshihiro Hirata, Motonari Uesugi, Ryosuke Tateishi, Keisuke Tateishi, Mitsuhiro Fujishiro, Kazuhiko Koike, Hayato Nakagawa
Virus-specific CD8+ T cells play a central role in HIV-1 natural controllers to maintain suppressed viremia in the absence of antiretroviral therapy. These cells display a memory program that confers them stemness properties, high survival, polyfunctionality, proliferative capacity, metabolic plasticity, and antiviral potential. The development and maintenance of such qualities by memory CD8+ T cells appear crucial to achieving natural HIV-1 control. Here we show that targeting the signaling pathways Wnt/TCF-1 and mTORC through GSK3 inhibition to reprogram HIV-specific CD8+ T cells from non-controllers promoted functional capacities associated with natural control of infection. Features of such reprogrammed cells included the enrichment in TCF-1+ less-differentiated subsets, superior response to antigen, enhanced survival, polyfunctionality, metabolic plasticity, less mTORC1-dependency, improved response to γ-chain cytokines and stronger HIV suppressive capacity. Thus, such CD8+ T cell reprogramming, combined with other available immunomodulators, might represent a promising strategy for adoptive cell therapy in the search for an HIV-1 cure.
Federico Perdomo-Celis, Caroline Passaes, Valérie Monceaux, Stevenn Volant, Faroudy Boufassa, Pierre de Truchis, Morgane Marcou, Katia Bourdic, Laurence Weiss, Corinne Jung, Christine Bourgeois, Cécile Goujard, Laurence Meyer, Michaela Müller-Trutwin, Olivier Lambotte, Asier Sáez-Cirión
Ischemic stroke prompts a strong inflammatory response which is associated with exacerbated outcomes. In this study, we investigated mechanistic regulators of neutrophil extracellular trap (NET) formation in stroke and if they contribute to stroke outcomes. NET forming neutrophils were found throughout brain tissue of ischemic stroke patients and elevated plasma NET biomarkers correlated with worse stroke outcomes. Additionally, we observed increased plasma and platelet surface expressed high mobility group box 1 (HMGB1) in stroke patients. Mechanistically, platelets were identified as the critical source for HMGB1 causing NETs in the acute phase of stroke. Depleting platelets or platelet-specific knockout of HMGB1 significantly reduced plasma HMGB1 and NET levels after stroke, and greatly improved stroke outcomes. We subsequently investigated the therapeutic potential of neonatal NET inhibitory factor (nNIF) in stroke. Mice treated with nNIF had smaller brain infarcts, improved long-term neurological and motor function, and enhanced survival after stroke. nNIF specifically blocked NET formation without affecting neutrophil recruitment after stroke. Importantly, nNIF also improved stroke outcomes in diabetic and aged mice and was still effective when given 1 hour after stroke onset. These results support a pathological role for NETs in ischemic stroke and warrant further investigation of nNIF for stroke therapy.
Frederik Denorme, Irina Portier, John L. Rustad, Mark J. Cody, Claudia V. de Araujo, Chieko Hoki, Matthew D. Alexander, Ramesh Grandhi, Mitchell R. Dyer, Matthew D. Neal, Jennifer J. Majersik, Christian C. Yost, Robert A. Campbell
BACKGROUND. It is unclear whether the level of serum hepatitis B virus (HBV) DNA at baseline impacts the on-treatment risk of hepatocellular carcinoma (HCC) in HBeAg positive, non-cirrhotic patients with chronic hepatitis B (CHB). METHODS. We conducted a multicenter cohort study including 2,073 entecavir- or tenofovir-treated, HBeAg-positive, non-cirrhotic, adult CHB patients with baseline HBV DNA levels ≥5.00 log10 IU/mL at three centers in Korea between January 2007 and December 2016. We evaluated the on-treatment incidence rate of HCC by baseline HBV DNA levels. RESULTS. During a median 5.7 years of continuous antiviral treatment, 47 patients developed HCC (0.39 per 100 person-years). By Kaplan–Meier analysis, HCC risk was the lowest in those with baseline HBV DNA levels ≥8.00 log10 IU/mL, increased incrementally with decreasing viral load, and the highest with HBV DNA levels 5.00–5.99 log10 IU/mL (P<0.001). By multivariable analysis, baseline HBV DNA level was an independent factor that was inversely associated with HCC risk. Compared with HBV DNA ≥8.00 log10 IU/mL, the adjusted hazard ratios for HCC risk with HBV DNA 7.00–7.99 log10 IU/mL, 6.00–6.99 log10 IU/mL, and 5.00–5.99 log10 IU/mL were 2.48 (P=0.03), 3.69 (P=0.002), and 6.10 (P<0.001), respectively. CONCLUSION. On-treatment HCC risk increased incrementally with decreasing baseline HBV DNA levels in the range of ≥5.00 log10 IU/mL in HBeAg-positive, non-cirrhotic, adult patients with CHB. Early initiation of antiviral treatment with a high viral load (≥8.00 log10 IU/mL) may maintain the lowest risk of HCC in those patients. FUNDING. Korean Government.
Won-Mook Choi, Gi-Ae Kim, Jonggi Choi, Seungbong Han, Young-Suk Lim
BACKGROUND. Tuberous Sclerosis Complex (TSC) is a neurogenetic syndrome due to loss-of-function mutations in TSC2 or TSC1, characterized by tumors at multiple body sites, including facial angiofibroma (FAF). Here, an ultrasensitive assessment of the extent and range of UV-induced mutations in TSC facial skin was performed. METHODS. A Multiplex High-sensitivity PCR Assay (MHPA) was developed, enabling mutation detection at extremely low (<0.1%) variant allele frequencies (VAF). RESULTS. MHPA assays were developed for both TSC2 and TP53, and applied to 81 samples, including 66 skin biopsies. UV-induced second hit mutation causing inactivation of TSC2 was pervasive in TSC facial skin with an average of 4.8 mutations per 2 mm biopsy at median VAF 0.08%, generating >150,000 incipient facial tumors (subclinical ‘micro-FAFs’) in the average TSC subject. The MHPA analysis also led to the identification of a refined UV-related indel signature and a recurrent complex mutation pattern, consisting of both a single or dinucleotide variant, and a 1-9 nt deletion, in cis. CONCLUSION. TSC facial skin can be viewed as harboring a patchwork of clonal fibroblast proliferations (micro-FAF) with indolent growth, a small proportion of which develop into clinically observable FAF. Our observations also expand the spectrum of UV-related mutation signatures. FUNDING. This work was supported by the TSC Alliance, Engles Family Fund for Research in TSC and LAM, and National Institutes of Health, National Heart, Lung, and Blood Institute [U01HL131022-04; Intramural Research Program].
Katarzyna Klonowska, Joannes M. Grevelink, Krinio Giannikou, Barbara A. Ogorek, Zachary T. Herbert, Aaron R. Thorner, Thomas N. Darling, Joel Moss, David J. Kwiatkowski
Pericytes (PC) are abundant yet remain the most enigmatic and ill-defined cell population in the heart. Here, we investigated if PC can be reprogrammed to aid neovascularization. Primary PC from human and mouse hearts acquired cytoskeleton proteins typical of vascular smooth muscle cells (VSMC) upon exclusion of EGF/bFGF, which signal through ERK1/2, or exposure to the MEK-inhibitor PD0325901. Differentiated PC became more proangiogenic, more responsive to vasoactive agents, and insensitive to chemoattractants. RNA-Sequencing revealed transcripts marking the PD0325901-induced transition into proangiogenic, stationary VSMC-like cells, including the unique expression of two angiogenesis-related markers, aquaporin 1 (AQP1) and cellular retinoic acid-binding protein 2 (CRABP2), which were further verified at the protein level. This enabled us to trace PC during in vivo studies. In mice, implantation of Matrigel plugs containing human PC+PD0325901 promoted the formation of α-SMApos neovessels compared with PC only. Two-week oral administration of PD0325901 to mice increased the heart arteriolar density, total vascular area, arteriole coverage by PDGFRβposAQP1posCRABP2pos PC, and myocardial perfusion. Short-duration PD0325901 treatment of mice after myocardial infarction enhanced the peri-infarct vascularization, reduced the scar, and improved systolic function. In conclusion, myocardial PC have intrinsic plasticity that can be pharmacologically modulated to promote reparative vascularization of the ischemic heart.
Elisa Avolio, Rajesh Katare, Anita C. Thomas, Andrea Caporali, Daryl Schwenke, Michele Carrabba, Marco Meloni, Massimo Caputo, Paolo Madeddu
Nonalcoholic fatty liver disease (NAFLD), the most common liver disease has become a silent worldwide pandemic. The incidence of NAFLD correlates with the rise in obesity, type 2 diabetes and metabolic syndrome. A hallmark feature of NAFLD is excessive hepatic fat accumulation or steatosis, due to dysregulated hepatic fat metabolism which can progress to nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Currently, there are no approved pharmacotherapies to treat this disease. Here we have identified that activation of the kisspeptin receptor (KISS1R) signaling pathway has therapeutic effects in NAFLD. Using high fat diet-fed mice, we demonstrated that a deletion of hepatic Kiss1r exacerbated hepatic steatosis. In contrast, enhanced stimulation of KISS1R protected against steatosis in wild-type C57BL/6J mice and decreased fibrosis using a diet-induced mouse model of NASH. Mechanistically, we found that hepatic KISS1R signaling activates the master energy regulator, AMPK, to thereby decrease lipogenesis and progression to NASH. In NAFLD patients and in HFD-fed mice, hepatic KISS1/KISS1R expression and plasma kisspeptin levels were elevated, suggesting a compensatory mechanism to reduce triglyceride synthesis. These findings establish KISS1R as a therapeutic target to treat NASH.
Stephania Guzman, Magdalena Dragan, Hyokjoon Kwon, Vanessa de Oliveira, Shivani Rao, Vrushank Bhatt, Katarzyna M. Kalemba, Ankit Shah, Vinod K. Rustgi, He Wang, Paul R. Bech, Ali Abbara, Chioma Izzi-Engbeaya, Pinelopi Manousou, Jessie Yanxiang Guo, Grace L. Guo, Sally Radovick, Waljit S. Dhillo, Fredric E. Wondisford, Andy V. Babwah, Moshmi Bhattacharya
Food addiction is characterized by a loss of behavioral control over food intake and is associated with obesity and other eating disorders. The mechanisms underlying this behavioral disorder are largely unknown. We aim to investigate the changes in miRNAs expression promoted by food addiction in animals and humans and their involvement in the mechanisms underlying the behavioral hallmarks of this disorder. Sharp similitudes were found between the miRNAs signatures in the medial prefrontal cortex (mPFC) of our animal cohort and the miRNAs circulating levels in our human cohort allowing to identify several miRNAs of potential interest for the development of this disorder. TuD inhibition of miRNA-29c-3p in the mouse mPFC promotes persistence to response and enhances the vulnerability to develop food addiction, whereas miRNA-665-3p inhibition promotes compulsive-like behavior and also enhances food addiction vulnerability. In contrast, miRNA-137-3p inhibition in the mPFC does not affect the development of food addiction. Therefore, miRNA-29c-3p and miRNA-665-3p could be acting as protective factors towards food addiction. The elucidation of these novel epigenetic mechanisms provides advances toward innovative biomarkers and possible future interventions for food addiction and related disorders based on the strategies now available to modify miRNA activity and expression.
Alejandra García-Blanco, Laura Domingo-Rodriguez, Judit Cabana-Domínguez, Noèlia Fernàndez-Castillo, Laura Pineda-Cirera, Jordi Mayneris-Perxachs, Aurelijus Burokas, Jose Espinosa-Carrasco, Silvia Arboleya, Jessica Latorre, Catherine Stanton, Bru Cormand, Jose-Manuel Fernández-Real, Elena Martín-García, Rafael Maldonado
Understanding the regulatory programs enabling cancer stem cells (CSCs) to self-renew and drive tumorigenicity could identify new treatments. Through comparative chromatin state and gene expression analyses in ovarian CSCs vs. non-CSCs, we identified FOXK2 as a highly expressed stemness-specific transcription factor in ovarian cancer. Its genetic depletion diminished stemness features and reduced tumor initiation capacity. Our mechanistic studies highlight that FOXK2 directly regulated IRE1α (ERN1 gene) expression, a key sensor for the unfolded protein response (UPR). Chromatin immunoprecipitation-sequencing revealed that FOXK2 bound to an intronic regulatory element of ERN1. Blocking FOXK2 from binding to this enhancer by using a catalytically inactive CRISPR/Cas9 (dCas9) diminished IRE1α transcription. At the molecular level, FOXK2-driven upregulation of IRE1α led to alternative XBP1 splicing and activation of stemness pathways, while genetic or pharmacological blockade of this sensor of the UPR inhibited ovarian CSCs. Collectively, these data establish a new function for FOXK2 as a key transcriptional regulator of CSCs and a mediator of the UPR, providing insight into potentially targetable new pathways in CSCs.
Yaqi Zhang, Yinu Wang, Guangyuan Zhao, Edward J. Tanner, Mazhar Adli, Daniela Matei
BACKGROUND. Responses to conventional donor lymphocyte infusion (DLI) for post-allogeneic hematopoietic cell transplantation (HCT) relapse are typically poor. Natural killer (NK) cell-based therapy is a promising modality to treat post-HCT relapse. METHODS. We initiated this ongoing phase I trial of adoptively transferred cytokine induced memory-like (CIML) NK cells in patients with myeloid malignancies relapsed after haploidentical HCT. All patients received a donor-derived NK cell dose of 5–10 million cells/kg after lymphodepleting chemotherapy, followed by systemic IL-2 for 7 doses. High resolution profiling with mass cytometry and single cell RNA sequencing characterized the expanding and persistent NK cell subpopulations in a longitudinal manner after infusion. RESULTS. In the first 6 enrolled patients on the trial, infusion of CIML NK cells led to a rapid 10 to 50-fold in vivo expansion that was sustained over months. The infusion was well-tolerated, with fever and pancytopenia as the most common adverse events. Expansion of NK cells was distinct from IL-2 effects on endogenous post-HCT NK cells, and not dependent on CMV viremia. Immunophenotypic and transcriptional profiling revealed a dynamic evolution of the activated CIML NK cell phenotype, superimposed on the natural variation in donor NK cell repertoires. CONCLUSION. Given their rapid expansion and long-term persistence in an immune compatible environment, CIML NK cells serve as a promising platform for the treatment of post-transplant relapse of myeloid disease. Further characterization of their unique in vivo biology and interaction with both T cells and tumor targets will lead to improvements in cell-based immunotherapies. TRIAL REGISTRATION. NCT04024761 FUNDING. Supported by Dunkin Donuts Breakthrough Award, the NIH/National Cancer Institute R21 CA245413, the Leukemia and Lymphoma Society Scholar and TRP awards.
Roman M. Shapiro, Grace C. Birch, Guangan Hu, Juliana Vergara Cadavid, Sarah Nikiforow, Joanna Baginska, Alaa K. Ali, Mubin Tarannum, Michal Sheffer, Yasmin Z. Abdulhamid, Benedetta Rambaldi, Yohei Arihara, Carol Reynolds, Max S. Halpern, Scott J. Rodig, Nicole Cullen, Jacquelyn O. Wolff, Kathleen L. Pfaff, Andrew A. Lane, R. Coleman Lindsley, Corey S. Cutler, Joseph H. Antin, Vincent T. Ho, John Koreth, Mahasweta Gooptu, Haesook T. Kim, Karl-Johan Malmberg, Catherine J. Wu, Jianzhu Chen, Robert J. Soiffer, Jerome Ritz, Rizwan Romee
As blood transitions from steady laminar flow (S-flow) in healthy arteries to disturbed flow (D-flow) in aneurysmal arteries, platelets are subjected to external forces. Biomechanical platelet activation is incompletely understood and is a potential mechanism behind antiplatelet medication resistance. While it was demonstrated that anti-platelet drugs suppress growth of abdominal aortic aneurysms (AAA) in patients, we revealed a certain degree of platelet reactivity persisted in spite of aspirin therapy urging us to consider additional anti-platelet therapeutic targets. Transcriptomic profiling of platelets from patients with AAA revealed upregulation of a signal transduction pathway common to olfactory receptors (ORs), and this was explored as a mediator of AAA progression. Healthy platelets subjected to D-flow ex vivo, platelets from patients with AAA, and platelets in murine models of AAA demonstrated increased membrane olfactory receptor 2L13 (OR2L13) expression. A drug screen identified a molecule activating platelet OR2L13 which limited both biochemical and biomechanical platelet activation as well as AAA growth. This observation was further supported by selective deletion of the OR2L13 ortholog in a murine model of AAA that accelerated aortic aneurysm growth and rupture. These studies reveal that ORs regulate platelet activation in AAA and aneurysmal progression through platelet-derived mediators of aortic remodeling.
Craig N. Morrell, Doran Mix, Anu Aggarwal, Rohan Bhandari, Matthew Godwin, A. Phillip Owens III, Sean P. Lyden, Adam Doyle, Krystin Krauel, Matthew T. Rondina, Amy Mohan, Charles J. Lowenstein, Sharon Shim, Shaun Stauffer, Vara Prasad Josyula, Sara K. Ture, David I. Yule, Larry E. Wagner III, John M. Ashton, Ayman Elbadawi, Scott J. Cameron
BACKGROUND. Myotonic dystrophy type 1 (DM1) is a complex life-limiting neuromuscular disorder characterized by severe skeletal muscle atrophy, weakness, and cardio-respiratory defects. Exercised DM1 mice exhibit numerous physiological benefits that are underpinned by reduced CUG foci and improved alternative splicing. However, the efficacy of physical activity in patients is unknown. METHODS. Eleven genetically diagnosed DM1 patients were recruited to examine the extent to which 12-weeks of cycling can recuperate clinical, and physiological metrics. Furthermore, we studied the underlying molecular mechanisms through which exercise elicits benefits in skeletal muscle of DM1 patients. RESULTS. DM1 was associated with impaired muscle function, fitness, and lung capacity. Cycling evoked several clinical, physical, and metabolic advantages in DM1 patients. We highlight that exercise-induced molecular and cellular alterations in patients do not conform with previously published data in murine models and propose a significant role of mitochondrial function in DM1 pathology. Lastly, we discovered a subset of small nucleolar RNAs (snoRNAs) that correlated to indicators of disease severity. CONCLUSION. With no available cures, our data supports the efficacy of exercise as a primary intervention to partially mitigate the clinical progression of DM1. Additionally, we provide evidence for the involvement of snoRNAs and other noncoding RNAs in DM1 pathophysiology. TRIAL REGISTRATION. This trial was approved by the HiREB committee (#7901) and registered under ClinicalTrials.gov (NCT04187482). FUNDING. This work was primarily supported by Neil and Leanne Petroff. This study was also supported by a Canadian Institutes of Health Research Foundation Grant to MAT (#143325).
Andrew I. Mikhail, Peter L. Nagy, Katherine Manta, Nicholas Rouse, Alexander Manta, Sean Y. Ng, Michael F. Nagy, Paul Smith, Jian-Qiang Lu, Joshua P. Nederveen, Vladimir Ljubicic, Mark A. Tarnopolsky
People living with HIV (PLWH) who are Immune Non-Responders (INR) persons are at greater risk of comorbidity and mortality than are Immune Responders (IR) who restore their CD4 T cells count (IR) after anti-retroviral therapy (ART). INR have low CD4-T cell counts (<350 c/ul), heightened systemic inflammation, and increased CD4-T cell cycling (Ki67+). Here we report the findings that memory CD4-T cells and plasma samples of INR from several cohorts are enriched in gut-derived bacterial solutes (GDBS) p-cresol-sulfate (PCS) and indoxyl sulfate (IS) that both negatively correlated with CD4-T cell counts. In vitro PCS or IS blocked CD4-T cell proliferation, induced apoptosis, and diminished the expression of mitochondrial proteins. Electron microscopy imaging (EMI) revealed perturbations of mitochondria networks similar to those found in INR following incubation of healthy memory CD4-T cells with PCS. Using the bacterial 16S rDNA, INR stool samples were found enriched with proteolytic bacterial genera that metabolize tyrosine and phenylalanine amino acids to produce PCS. We propose that toxic solutes from the gut bacterial flora may impair CD4-T cell recovery during ART and may contribute to CD4-T cell lymphopenia characteristic of INR.
Brian Ferrari, Amanda Cabral Da Silva, Ken H. Liu, Evgeniya V. Saidakova, Larisa B. Korolevskaya, Konstantin V. Shmagel, Carey Shive, Gabriela Pacheco Sanchez, Mauricio Retuerto, Ashish Arunkumar Sharma, Khader Ghneim, Laura Noel-Romas, Benigno Rodriguez, Mahmoud A. Ghannoum, Peter P. Hunt, Steven G. Deeks, Adam D. Burgener, Dean P. Jones, Mirela A. Dobre, Vincent C. Marconi, Rafick-Pierre Sekaly, Souheil-Antoine Younes
The synthesis of serine from glucose is a key metabolic pathway supporting cellular proliferation in healthy and malignant cells. Despite this, the role that this aspect of metabolism plays in germinal center biology and pathology is not known. Here, we performed a comprehensive characterization of the role of the serine synthesis pathway in germinal center B cells and lymphomas derived from these cells. We demonstrated that upregulation of a functional serine synthesis pathway is a metabolic hallmark of B-cell activation and the germinal center reaction. Inhibition of phosphoglycerate dehydrogenase (PHGDH), the first and rate limiting enzyme in this pathway, led to defective germinal formation and impaired high-affinity antibody production. In addition, overexpression of enzymes involved in serine synthesis was a characteristic of germinal center B-cell derived lymphomas, with high levels of expression being predictive of reduced overall survival in diffuse large B cell lymphoma. Inhibition of PHGDH induced apoptosis in lymphoma cells reducing disease progression. These findings establish PHGDH as a critical player in humoral immunity and a clinically relevant target in lymphoma.
Annalisa D'Avola, Nathalie Legrave, Mylène Tajan, Probir Chakravarty, Ryan L. Shearer, Hamish W. King, Katarina Kluckova, Eric C. Cheung, Andrew J. Clear, Arief S. Gunawan, Lingling Zhang, Louisa K. James, James I. MacRae, John G. Gribben, Dinis P. Calado, Karen H. Vousden, John C. Riches
T cell immunoglobulin mucin domain-containing protein 3 (Tim-3) negatively regulates innate and adaptive immunity in cancer. To identify the mechanisms of Tim-3 in cancer immunity, we evaluated the effects of Tim-3 blockade in human and mouse melanoma. Here, we show that human PD-1+Tim-3+ CD8+ tumor-infiltrating lymphocytes (TILs) upregulate phosphatidylserine (PS), a receptor for Tim-3, and acquire cell surface myeloid markers from antigen presenting cells (APCs) through transfer of membrane fragments called trogocytosis. Tim-3 blockade acted on Tim-3+ APCs in a PS-dependent fashion to disrupt the trogocytosis of activated tumor antigen-specific CD8+ T cells and PD-1+Tim-3+ CD8+ TILs isolated from melanoma patients. Tim-3 and PD-1 blockades cooperated to disrupt trogocytosis of CD8+ TILs in two melanoma mouse models, decreasing tumor burden and prolonging survival. Deleting Tim-3 in dendritic cells but not on CD8+ T cells impeded the trogocytosis of CD8+ TILs in vivo. Trogocytosed CD8+ T cells presented tumor peptide-major histocompatibility complexes and became the target of fratricide T cell killing, which was reversed by Tim-3 blockade. Our findings have uncovered a mechanism used by Tim-3 to limit antitumor immunity.
Ornella Pagliano, Robert M. Morrison, Joe-Marc Chauvin, Hridesh Banerjee, Diwakar Davar, Quanquan Ding, Tokiyoshi Tanegashima, Wentao Gao, Saranya Rani Chakka, Richelle DeBlasio, Ava Lowin, Kevin Kara, Mignane Ka, Bochra Zidi, Rada Amin, Itay Raphael, Shuowen Zhang, Simon C. Watkins, Cindy Sander, John M. Kirkwood, Marcus Bosenberg, Ana C. Anderson, Vijay K. Kuchroo, Lawrence P. Kane, Alan J. Korman, Arvind Rajpal, Sean M. West, Minhua Han, Christine Bee, Xiaodi Deng, Xiao Min Schebye, Pavel Strop, Hassane M. Zarour
Pregnancy is associated with substantial physiological changes of the heart, and disruptions in these processes can lead to peripartum-cardiomyopathy (PPCM). The molecular processes that cause physiological and pathological changes in the heart during pregnancy are not well characterized. Here, we show that mTORc1 was activated in pregnancy to facilitate cardiac enlargement that was reversed after delivery in mice. mTORc1 activation in pregnancy was negatively regulated by the mRNA-destabilizing-protein ZFP36L2 through its degradation of Mdm2 mRNA and P53 stabilization, leading to increased SESN2 and REDD1 expression. This pathway impeded uncontrolled cardiomyocytes hypertrophy during pregnancy, and mice with cardiac-specific Zfp36l2 deletion developed rapid cardiac dysfunction after delivery, while prenatal treatment of these mice with rapamycin improved post-partum cardiac function. Collectively, these data provide a novel pathway for the regulation of mTORc1 through mRNA stabilization of a P53 ubiquitin ligase. This pathway was critical for normal cardiac growth during pregnancy, and its reduction led to PPCM-like adverse remodeling in mice.
Hidemichi Kouzu, Yuki Tatekoshi, Hsiang-Chun Chang, Jason S. Shapiro, Warren A. McGee, Adam De Jesus, Issam Ben-Sahra, Zoltan Arany, Jonathan Leor, Chunlei Chen, Perry J. Blackshear, Hossein Ardehali
Pericyte-mediated capillary constriction decreases cerebral blood flow in stroke after an occluded artery is unblocked. The determinants of pericyte tone are poorly understood. We show that a small rise in cytoplasmic Ca2+ concentration ([Ca2+]i) in pericytes activates chloride efflux through the Ca2+-gated anion channel TMEM16A, thus depolarizing the cell and opening voltage-gated calcium channels. This mechanism strongly amplifies the pericyte [Ca2+]i rise and capillary constriction evoked by contractile agonists and ischemia. In a rodent stroke model, TMEM16A inhibition slows the ischemia-evoked pericyte [Ca2+]i rise, capillary constriction and pericyte death, reduces neutrophil stalling and improves cerebrovascular reperfusion. Genetic analysis implicates altered TMEM16A expression in poor patient recovery from ischemic stroke. Thus, pericyte TMEM16A is a crucial regulator of cerebral capillary function, and a potential therapeutic target for stroke and possibly other disorders of impaired microvascular flow, such as Alzheimer’s disease and vascular dementia.
Nils Korte, Zeki Ilkan, Claire L. Pearson, Thomas Pfeiffer, Prabhav Singhal, Jason R. Rock, Huma Sethi, Dipender Gill, David Attwell, Paolo Tammaro
BACKGROUND. The Delta and Omicron variants of SARS-CoV-2 are currently responsible for breakthrough infections due to waning immunity. We report phase 1/2 trial results of UB-612, a multitope subunit vaccine containing S1-RBD-sFc protein and rationally-designed promiscuous peptides representing Sarbecovirus conserved Th and CTL epitopes on the nucleocapsid (N), membrane (M) and spike (S2) proteins. METHODS. We conducted a phase-1 primary 2-dose (28-day apart) trial of 10-, 30-, or 100-μg UB-612 in sixty healthy young adults aged 20-55 years, and fifty of them were boosted with 100-μg of UB-612 ~7-9 months post-2nd dose. A separate placebo-controlled and randomized phase-2 study was conducted with two doses of 100-μg UB-612 (n = 3,875, aged 18-85 years). We evaluated interim safety and immunogenicity of the phase-1 until 14 days post-3rd (booster) dose and of the phase-2 until 28 days post-2nd dose. RESULTS. No vaccine-related serious adverse events (SAE) were recorded. The most common solicited AEs were injection site pain and fatigue, mostly mild and transient. In both trials, UB-612 elicited respective neutralizing antibody titers similar to a panel of human convalescent sera. The most striking findings were: long-lasting viral-neutralizing antibodies and broad T-cell immunity against SARS-CoV2 Variants of Concern (VoCs) including Delta and Omicron, and a strong booster-recalled memory immunity with high cross-reactive neutralizing titers against the Delta and Omicron variants. CONCLUSION. UB-612 has presented a favorable safety profile, potent booster effect against VoCs, and long-lasting B- and broad T-cell immunity that warrants further development for both primary immunization and heterologous boosting of other COVID-19 vaccines. TRIAL REGISTRATION. Clinical Trials.gov: NCT04545749, NCT04773067 and NCT04967742. FUNDING. United Biomedical Inc., Asia, Vaxxinity Inc., and Taiwan Centers for Disease Control, Ministry of Health and Welfare.
Chang Yi Wang, Kao-Pin Hwang, Hui-Kai Kuo, Wen-Jiun Peng, Yea-Huei Shen, Be-Sheng Kuo, Juin-Hua Huang, Hope Liu, Yu-Hsin Ho, Feng Lin, Shuang Ding, Zhi Liu, Huan-Ting Wu, Ching-Tai Huang, Yuarn-Jang Lee, Ming-Che Liu, Yi-Ching Yang, Po-Liang Lu, Hung-Chin Tsai, Chen-Hsiang Lee, Zhi-Yuan Shi, Chun-Eng Liu, Chun-Hsing Liao, Feng-Yee Chang, Hsiang-Cheng Cheng, Fu-Der Wang, Kuo-Liang Hou, Jennifer Cheng, Min-Sheng Wang, Ya-Ting Yang, Han-Chen Chiu, Ming-Han Jiang, Hao-Yu Shih, Hsuan-Yu Shen, Po-Yen Chang, Yu-Rou Lan, Chi-Tian Chen, Yi-Ling Lin, Jian-Jong Liang, Chun-Che Liao, Yu-Chi Chou, Mary Kate Morris, Carl V. Hanson, Farshad Guirakhoo, Michael Hellerstein, Hui Jing Yu, Chwan-Chuen King, Tracy Kemp, D. Gray Heppner, Thomas P. Monath
Proliferation of latently-infected CD4+ T cells with replication-competent proviruses is an important mechanism contributing to HIV persistence during antiretroviral therapy (ART). One approach to target this latent cell expansion is to inhibit the mechanistic target of rapamycin (mTOR), a regulatory kinase involved with cell growth, metabolism and proliferation. Here we determined the effects of chronic mTOR inhibition with rapamycin +/- T cell activation in SIV-infected rhesus macaques (RM) on ART. Rapamycin perturbed the expression of multiple genes and signaling pathways important for cellular proliferation and substantially decreased the frequencies of proliferating CD4+ memory T cells (TM) in blood and tissues. However, levels of cell-associated SIV DNA and SIV RNA were not markedly different between rapamycin-treated RM relative to controls during ART. T cell activation with an anti-CD3LALA antibody induced increases in SIV RNA in plasma of RM on rapamycin, consistent with SIV production. However, upon ART cessation, both rapamycin + CD3LALA-treated and control-treated RM rebounded in less than 12 days, with no difference in the time to viral rebound or post-ART viral load set points. These results indicate that while rapamycin can decrease the proliferation of CD4+ TM, chronic mTOR inhibition alone or in combination with T cell activation, was not sufficient to disrupt the stability of the SIV reservoir.
Benjamin D. Varco-Merth, William Brantley, Alejandra Marenco, Derick D. Duell, Devin N. Fachko, Brian Richardson, Kathleen Busman-Sahay, Danica Shao, Walter Flores, Kathleen Engelman, Yoshinori Fukazawa, Scott W. Wong, Rebecca L. Skalsky, Jeremy Smedley, Michael K Axthelm, Jeffrey D. Lifson, Jacob D. Estes, Paul T. Edlefsen, Louis Picker, Cheryl M.A. Cameron, Timothy J. Henrich, Afam A. Okoye
The loss function of cerebral cavernous malformation (CCM) genes leads to most CCM lesions characterized by enlarged leaking vascular lesions in the brain. Although we previously showed that NOGOB receptor (NGBR) knockout in endothelial cells (ECs) results in cerebrovascular lesions in the mouse embryo, the molecular mechanism by which NGBR regulates CCM1/2 expression has not been elucidated. Here, we show that temporal genetic depletion of Ngbr in ECs at both postnatal and adult stages results in CCM1/2 expression deficiency and cerebrovascular lesions such as enlarged vessels, blood-brain barrier (BBB) hyperpermeability, and cerebral hemorrhage. To reveal the molecular mechanism, we used RNA-seq analysis to examine changes in the transcriptome. Surprisingly, we found that acetyltransferase HBO1 and histone acetylation were downregulated in NGBR deficient ECs. The mechanistic studies elucidated that NGBR is required for maintaining the expression of CCM1/2 in ECs via HBO1-mediated histone acetylation. ChIP-qPCR data further demonstrated that loss of NGBR impairs the binding of both HBO1 and acetylated H4K5/K12 on the promotor of CCM1 and CCM2 genes. Our findings on epigenetic regulation of CCM1 and CCM2 that modulated by NGBR and HBO1-mediated histone H4 acetylation provide a perspective on the pathogenesis of sporadic CCMs.
Zhi Fang, Xiaoran Sun, Xiang Wang, Ji Ma, Thomas Palaia, Ujala Rana, Benjamin Miao, Louis Ragolia, Wenquan Hu, Qing Robert Miao