Issue published August 1, 2017 Previous issue | Next issue
On the cover: An inflammation-induced barrier to the brain
In this issue of the JCI, Horng et al. observed a protective response to inflammation in the glia limitans of mice and in cultured human astrocytes. Increases in blood-brain barrier permeability provoked tight junction formation in glia limitans astrocytes, creating an inducible barrier to leukocyte and humoral infiltration. On the cover, primary human astrocytes (red) corral CD3+ T lymphocytes (blue) within a network of tight junctions after exposure to proinflammatory IL-1β. Image credit: Candice Chapouly.
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Review
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Abstract
Type 1 diabetes (T1D) is a chronic autoimmune disease that causes severe loss of pancreatic β cells. Autoreactive T cells are key mediators of β cell destruction. Studies of organ donors with T1D that have examined T cells in pancreas, the diabetogenic insulitis lesion, and lymphoid tissues have revealed a broad repertoire of target antigens and T cell receptor (TCR) usage, with initial evidence of public TCR sequences that are shared by individuals with T1D. Neoepitopes derived from post-translational modifications of native antigens are emerging as novel targets that are more likely to evade self-tolerance. Further studies will determine whether T cell responses to neoepitopes are major disease drivers that could impact prediction, prevention, and therapy. This Review provides an overview of recent progress in our knowledge of autoreactive T cells that has emerged from experimental and clinical research as well as pathology investigations.
Authors
Alberto Pugliese
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Commentaries
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Abstract
Coronary revascularization is an effective means of treating ischemic heart disease; however, current therapeutic revascularization strategies are limited to large caliber vessels. Because the mammalian heart scars following cardiac injury, recent work showing that cardiac fibroblasts can transdifferentiate into new coronary endothelium raises a new and exciting approach to promoting endogenous revascularization following cardiac injury. In this issue of the JCI, He et al. report on their employment of a battery of lineage-tracing tools to address the developmental origins of fibroblasts that give rise to new endothelial cells. Surprisingly, cardiac fibroblasts did not appear to contribute appreciably to regeneration of cardiac endothelium. Instead, cardiac endothelial cells were likely to proliferate and generate new endothelium following injury. As these conclusions diverge from prior findings, additional work will be required to understand the sources that generate cardiac endothelium in new blood vessels after injury. Clarification of the origins of coronary endothelial cells during cardiac repair is essential for identifying improved approaches to revascularizing damaged myocardium in patients with ischemic heart disease.
Authors
Ravi Karra, Agoston O. Walter, Sean M. Wu
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Leukotrienes are proinflammatory lipid mediators that have been shown to be upregulated in several diseases, including asthma, aspirin-exacerbated respiratory disease (AERD), inflammatory bowel disease, and acute respiratory distress syndrome. Leukotrienes have been explored as therapeutic targets for these diseases and others; however, leukotriene inhibitors have had limited success in the clinic. There are noted differences in the incidence of leukotriene-mediated diseases in males and females, but sex as a factor in the response to leukotriene inhibitors has not been fully explored. In this issue of the JCI, Pace and colleagues present evidence that there are sex-specific differences in the effectiveness of certain leukotriene inhibitors and link the differences in response to the presence of androgens. The results of this study indicate that sex needs to be taken into consideration in the future evaluation of leukotriene inhibitors to treat disease.
Authors
Lewis J. Smith
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The blood-brain barrier (BBB) and the glia limitans serve to prevent the migration of cells and other large molecules from the blood into the CNS. Neuroinflammatory diseases are characterized by disruption of the BBB and increased leukocyte infiltration into the CNS. In this issue of the JCI, Horng and colleagues demonstrate that astrocytes of the glia limitans induce tight junction formation in response to inflammatory cues, thereby tightening the border to limit the number of activated T cells infiltrating the CNS. Moreover, preventing the formation of this inducible barrier in mice increased disease severity in models of neuroinflammation. Together, the results of this study indicate that the inducible barrier of the glia limitans should be further explored as a therapeutic target.
Authors
Francisco J. Quintana
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Proteinopathies are characterized by the accumulation of misfolded proteins, which ultimately interfere with normal cell function. While neurological diseases, such as Huntington disease and Alzheimer disease, are well-characterized proteinopathies, cardiac diseases have recently been associated with alterations in proteostasis. In this issue of the JCI, Fang and colleagues demonstrate that mice with cardiac-specific deficiency of the co-chaperone protein BCL2-associated athanogene 3 (BAG3) develop dilated cardiomyopathy that is associated with a destabilization of small HSPs as the result of a disrupted interaction between BAG3 and HSP70. Together, the results of this study suggest that strategies to upregulate BAG3 during cardiac dysfunction may be beneficial.
Authors
Wataru Mizushima, Junichi Sadoshima
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Research Articles
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Abstract
Atherosclerosis is a chronic inflammatory disease, and developing therapies to promote its regression is an important clinical goal. We previously established that atherosclerosis regression is characterized by an overall decrease in plaque macrophages and enrichment in markers of alternatively activated M2 macrophages. We have now investigated the origin and functional requirement for M2 macrophages in regression in normolipidemic mice that received transplants of atherosclerotic aortic segments. We compared plaque regression in WT normolipidemic recipients and those deficient in chemokine receptors necessary to recruit inflammatory Ly6Chi (Ccr2–/– or Cx3cr1–/–) or patrolling Ly6Clo (Ccr5–/–) monocytes. Atherosclerotic plaques transplanted into WT or Ccr5–/– recipients showed reduced macrophage content and increased M2 markers consistent with plaque regression, whereas plaques transplanted into Ccr2–/– or Cx3cr1–/– recipients lacked this regression signature. The requirement of recipient Ly6Chi monocyte recruitment was confirmed in cell trafficking studies. Fate-mapping and single-cell RNA sequencing studies also showed that M2-like macrophages were derived from newly recruited monocytes. Furthermore, we used recipient mice deficient in STAT6 to demonstrate a requirement for this critical component of M2 polarization in atherosclerosis regression. Collectively, these results suggest that continued recruitment of Ly6Chi inflammatory monocytes and their STAT6-dependent polarization to the M2 state are required for resolution of atherosclerotic inflammation and plaque regression.
Authors
Karishma Rahman, Yuliya Vengrenyuk, Stephen A. Ramsey, Noemi Rotllan Vila, Natasha M. Girgis, Jianhua Liu, Viktoria Gusarova, Jesper Gromada, Ada Weinstock, Kathryn J. Moore, P’ng Loke, Edward A. Fisher
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Non-muscle–invasive bladder cancer (NMIBC) is a highly recurrent tumor despite intravesical immunotherapy instillation with the bacillus Calmette-Guérin (BCG) vaccine. In a prospective longitudinal study, we took advantage of BCG instillations, which increase local immune infiltration, to characterize immune cell populations in the urine of patients with NMIBC as a surrogate for the bladder tumor microenvironment. We observed an infiltration of neutrophils, T cells, monocytic myeloid-derived suppressor cells (M-MDSCs), and group 2 innate lymphoid cells (ILC2). Notably, patients with a T cell–to-MDSC ratio of less than 1 showed dramatically lower recurrence-free survival than did patients with a ratio of greater than 1. Analysis of early and later time points indicated that this patient dichotomy existed prior to BCG treatment. ILC2 frequency was associated with detectable IL-13 in the urine and correlated with the level of recruited M-MDSCs, which highly expressed IL-13 receptor α1. In vitro, ILC2 were increased and potently expressed IL-13 in the presence of BCG or tumor cells. IL-13 induced the preferential recruitment and suppressive function of monocytes. Thus, the T cell–to-MDSC balance, associated with a skewing toward type 2 immunity, may predict bladder tumor recurrence and influence the mortality of patients with muscle-invasive cancer. Moreover, these results underline the ILC2/IL-13 axis as a targetable pathway to curtail the M-MDSC compartment and improve bladder cancer treatment.
Authors
Mathieu F. Chevalier, Sara Trabanelli, Julien Racle, Bérengère Salomé, Valérie Cesson, Dalila Gharbi, Perrine Bohner, Sonia Domingos-Pereira, Florence Dartiguenave, Anne-Sophie Fritschi, Daniel E. Speiser, Cyrill A. Rentsch, David Gfeller, Patrice Jichlinski, Denise Nardelli-Haefliger, Camilla Jandus, Laurent Derré
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Programmed death-1–directed (PD-1–directed) immune checkpoint blockade results in durable antitumor activity in many advanced malignancies. Recent studies suggest that IFN-γ is a critical driver of programmed death ligand-1 (PD-L1) expression in cancer and host cells, and baseline intratumoral T cell infiltration may improve response likelihood to anti–PD-1 therapies, including pembrolizumab. However, whether quantifying T cell–inflamed microenvironment is a useful pan-tumor determinant of PD-1–directed therapy response has not been rigorously evaluated. Here, we analyzed gene expression profiles (GEPs) using RNA from baseline tumor samples of pembrolizumab-treated patients. We identified immune-related signatures correlating with clinical benefit using a learn-and-confirm paradigm based on data from different clinical studies of pembrolizumab, starting with a small pilot of 19 melanoma patients and eventually defining a pan-tumor T cell–inflamed GEP in 220 patients with 9 cancers. Predictive value was independently confirmed and compared with that of PD-L1 immunohistochemistry in 96 patients with head and neck squamous cell carcinoma. The T cell–inflamed GEP contained IFN-γ–responsive genes related to antigen presentation, chemokine expression, cytotoxic activity, and adaptive immune resistance, and these features were necessary, but not always sufficient, for clinical benefit. The T cell–inflamed GEP has been developed into a clinical-grade assay that is currently being evaluated in ongoing pembrolizumab trials.
Authors
Mark Ayers, Jared Lunceford, Michael Nebozhyn, Erin Murphy, Andrey Loboda, David R. Kaufman, Andrew Albright, Jonathan D. Cheng, S. Peter Kang, Veena Shankaran, Sarina A. Piha-Paul, Jennifer Yearley, Tanguy Y. Seiwert, Antoni Ribas, Terrill K. McClanahan
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An increase in hepatic glucose production (HGP) represents a key feature of type 2 diabetes. This deficiency in metabolic control of glucose production critically depends on enhanced signaling through hepatic glucagon receptors (GCGRs). Here, we have demonstrated that selective inactivation of the GPCR-associated protein β-arrestin 2 in hepatocytes of adult mice results in greatly increased hepatic GCGR signaling, leading to striking deficits in glucose homeostasis. However, hepatocyte-specific β-arrestin 2 deficiency did not affect hepatic insulin sensitivity or β-adrenergic signaling. Adult mice lacking β-arrestin 1 selectively in hepatocytes did not show any changes in glucose homeostasis. Importantly, hepatocyte-specific overexpression of β-arrestin 2 greatly reduced hepatic GCGR signaling and protected mice against the metabolic deficits caused by the consumption of a high-fat diet. Our data support the concept that strategies aimed at enhancing hepatic β-arrestin 2 activity could prove useful for suppressing HGP for therapeutic purposes.
Authors
Lu Zhu, Mario Rossi, Yinghong Cui, Regina J. Lee, Wataru Sakamoto, Nicole A. Perry, Nikhil M. Urs, Marc G. Caron, Vsevolod V. Gurevich, Grzegorz Godlewski, George Kunos, Minyong Chen, Wei Chen, Jürgen Wess
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In rheumatoid arthritis (RA), immunological triggers at mucosal sites, such as the gut microbiota, may promote autoimmunity that affects joints. Here, we used discovery-based proteomics to detect HLA-DR–presented peptides in synovia or peripheral blood mononuclear cells and identified 2 autoantigens, N-acetylglucosamine-6-sulfatase (GNS) and filamin A (FLNA), as targets of T and B cell responses in 52% and 56% of RA patients, respectively. Both GNS and FLNA were highly expressed in synovia. GNS appeared to be citrullinated, and GNS antibody values correlated with anti–citrullinated protein antibody (ACPA) levels. FLNA did not show the same results. The HLA-DR–presented GNS peptide has marked sequence homology with epitopes from sulfatase proteins of the Prevotella sp. and Parabacteroides sp., whereas the HLA-DR–presented FLNA peptide has homology with epitopes from proteins of the Prevotella sp. and Butyricimonas sp., another gut commensal. Patients with T cell reactivity with each self-peptide also had responses to the corresponding microbial peptides, and the levels were directly correlated. Furthermore, HLA-DR molecules encoded by shared-epitope (SE) alleles were predicted to bind these self- and microbial peptides strongly, and these responses were more common in RA patients with SE alleles. Thus, sequence homology between T cell epitopes of 2 self-proteins and a related order of gut microbes may provide a link between mucosal and joint immunity in patients with RA.
Authors
Annalisa Pianta, Sheila L. Arvikar, Klemen Strle, Elise E. Drouin, Qi Wang, Catherine E. Costello, Allen C. Steere
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Seneca Valley virus (SVV) is an oncolytic picornavirus with selective tropism for neuroendocrine cancers. It has shown promise as a cancer therapeutic in preclinical studies and early-phase clinical trials. Here, we have identified anthrax toxin receptor 1 (ANTXR1) as the receptor for SVV using genome-wide loss-of-function screens. ANTXR1 is necessary for permissivity in vitro and in vivo. However, robust SVV replication requires an additional innate immune defect. We found that SVV interacts directly and specifically with ANTXR1, that this interaction is required for SVV binding to permissive cells, and that ANTXR1 expression is necessary and sufficient for infection in cell lines with decreased expression of antiviral IFN genes at baseline. Finally, we identified the region of the SVV capsid that is responsible for receptor recognition using cryoelectron microscopy of the SVV-ANTXR1-Fc complex. These studies identify ANTXR1, a class of receptor that is shared by a mammalian virus and a bacterial toxin, as the cellular receptor for SVV.
Authors
Linde A. Miles, Laura N. Burga, Eric E. Gardner, Mihnea Bostina, John T. Poirier, Charles M. Rudin
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The mechanisms that promote the generation of new coronary vasculature during cardiac homeostasis and after injury remain a fundamental and clinically important area of study in the cardiovascular field. Recently, it was reported that mesenchymal-to-endothelial transition (MEndoT) contributes to substantial numbers of coronary endothelial cells after myocardial infarction. Therefore, the MEndoT has been proposed as a paradigm mediating neovascularization and is considered a promising therapeutic target in cardiac regeneration. Here, we show that preexisting endothelial cells mainly beget new coronary vessels in the adult mouse heart, with essentially no contribution from other cell sources through cell-lineage transdifferentiation. Genetic-lineage tracing revealed that cardiac fibroblasts expand substantially after injury, but do not contribute to the formation of new coronary blood vessels, indicating no contribution of MEndoT to neovascularization. Moreover, genetic-lineage tracing with a pulse-chase labeling strategy also showed that essentially all new coronary vessels in the injured heart are derived from preexisting endothelial cells, but not from other cell lineages. These data indicate that therapeutic strategies for inducing neovascularization should not be based on targeting presumptive lineage transdifferentiation such as MEndoT. Instead, preexisting endothelial cells appear more likely to be the therapeutic target for promoting neovascularization and driving heart regeneration after injury.
Authors
Lingjuan He, Xiuzhen Huang, Onur Kanisicak, Yi Li, Yue Wang, Yan Li, Wenjuan Pu, Qiaozhen Liu, Hui Zhang, Xueying Tian, Huan Zhao, Xiuxiu Liu, Shaohua Zhang, Yu Nie, Shengshou Hu, Xiang Miao, Qing-Dong Wang, Fengchao Wang, Ting Chen, Qingbo Xu, Kathy O. Lui, Jeffery D. Molkentin, Bin Zhou
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The tumor microenvironment plays an important role in tumor growth and metastasis. However, the mechanism by which tumor cells regulate the cell and non-cell constituents of surrounding stroma remains incompletely understood. Promyelocytic leukemia (PML) is a pleiotropic tumor suppressor, but its role in tumor microenvironment regulation is poorly characterized. PML is frequently downregulated in many cancer types, including lung cancer. Here, we identify a PML ubiquitination pathway that is mediated by WD repeat 4–containing cullin-RING ubiquitin ligase 4 (CRL4WDR4). Clinically, this PML degradation pathway is hyperactivated in lung cancer and correlates with poor prognosis. The WDR4/PML axis induces a set of cell-surface or secreted factors, including CD73, urokinase-type plasminogen activator receptor (uPAR), and serum amyloid A2 (SAA2), which elicit paracrine effects to stimulate migration, invasion, and metastasis in multiple lung cancer models. In xenograft and genetically engineered mouse models, the WDR4/PML axis elevates intratumoral Tregs and M2-like macrophages and reduces CD8+ T cells to promote lung tumor growth. These immunosuppressive effects were all reversed by CD73 blockade. Our study identifies WDR4 as an oncoprotein that negatively regulates PML via ubiquitination to promote lung cancer progression by fostering an immunosuppressive and prometastatic tumor microenvironment, suggesting the potential of immune-modulatory approaches for treating lung cancer with aberrant PML degradation.
Authors
Ya-Ting Wang, Jocelyn Chen, Chou-Wei Chang, Jayu Jen, Tzu-Yu Huang, Chun-Ming Chen, Roger Shen, Suh-Yuen Liang, I-Cheng Cheng, Shuenn-Chen Yang, Wu-Wei Lai, Kuang-Hung Cheng, Tao-Shih Hsieh, Ming-Zong Lai, Hung-Chi Cheng, Yi-Ching Wang, Ruey-Hwa Chen
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Angioimmunoblastic T cell lymphoma (AITL) represents a distinct, aggressive form of peripheral T cell lymphoma with a dismal prognosis. Recent exome sequencing in patients with AITL has revealed the frequent coexistence of somatic mutations in the Rho GTPase RhoA (RhoAG17V) and loss-of-function mutations in the 5-methylcytosine oxidase TET2. Here, we have demonstrated that TET2 loss and RhoAG17V expression in mature murine T cells cooperatively cause abnormal CD4+ T cell proliferation and differentiation by perturbing FoxO1 gene expression, phosphorylation, and subcellular localization, an abnormality that is also detected in human primary AITL tumor samples. Reexpression of FoxO1 attenuated aberrant immune responses induced in mouse models adoptively transferred with T cells and bearing genetic lesions in both TET2 and RhoA. Our findings suggest a mutational cooperativity between epigenetic factors and GTPases in adult CD4+ T cells that may account for immunoinflammatory responses associated with AITL patients.
Authors
Shengbing Zang, Jia Li, Haiyan Yang, Hongxiang Zeng, Wei Han, Jixiang Zhang, Minjung Lee, Margie Moczygemba, Sevinj Isgandarova, Yaling Yang, Yubin Zhou, Anjana Rao, M. James You, Deqiang Sun, Yun Huang
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The WD40-containing E3 ubiquitin ligase RFWD3 has been recently linked to the repair of DNA damage by homologous recombination (HR). Here we have shown that an RFWD3 mutation within the WD40 domain is connected to the genetic disease Fanconi anemia (FA). An individual presented with congenital abnormalities characteristic of FA. Cells from the patient carrying the compound heterozygous mutations c.205_206dupCC and c.1916T>A in RFWD3 showed increased sensitivity to DNA interstrand cross-linking agents in terms of increased chromosomal breakage, reduced survival, and cell cycle arrest in G2 phase. The cellular phenotype was mirrored in genetically engineered human and avian cells by inactivation of RFWD3 or introduction of the patient-derived missense mutation, and the phenotype was rescued by expression of wild-type RFWD3 protein. HR was disrupted in RFWD3-mutant cells as a result of impaired relocation of mutant RFWD3 to chromatin and defective physical interaction with replication protein A. Rfwd3 knockout mice appear to have increased embryonic lethality, are subfertile, show ovarian and testicular atrophy, and have a reduced lifespan resembling that of other FA mouse models. Although RFWD3 mutations have thus far been detected in a single child with FA, we propose RFWD3 as an FA gene, FANCW, supported by cellular paradigm systems and an animal model.
Authors
Kerstin Knies, Shojiro Inano, María J. Ramírez, Masamichi Ishiai, Jordi Surrallés, Minoru Takata, Detlev Schindler
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BACKGROUND. Recessive dystrophic epidermolysis bullosa (RDEB) is an incurable disease caused by mutations in the gene encoding type VII collagen, the major component of anchoring fibrils (AF). We previously demonstrated that gentamicin produced functional type VII collagen in RDEB cells harboring nonsense mutations. Herein, we determined whether topical or intradermal gentamicin administration induces type VII collagen and AFs in RDEB patients. METHODS. A double-blind, placebo-controlled pilot trial assessed safety and efficacy of topical and intradermal gentamicin in 5 RDEB patients with nonsense mutations. The topical arm tested 0.1% gentamicin ointment or placebo application 3 times daily at 2 open erosion sites for 2 weeks. The intradermal arm tested daily intradermal injection of gentamicin solution (8 mg) or placebo into 2 intact skin sites for 2 days in 4 of 5 patients. Primary outcomes were induction of type VII collagen and AFs at the test sites and safety assessment. A secondary outcome assessed wound closure of topically treated erosions. RESULTS. Both topical and intradermal gentamicin administration induced type VII collagen and AFs at the dermal-epidermal junction of treatment sites. Newly created type VII collagen varied from 20% to 165% of that expressed in normal human skin and persisted for 3 months. Topical gentamicin corrected dermal-epidermal separation, improved wound closure, and reduced blister formation. There were no untoward side effects from gentamicin treatments. Type VII collagen induction did not generate anti–type VII collagen autoantibodies in patients’ blood or skin. CONCLUSION. Topical and intradermal gentamicin suppresses nonsense mutations and induces type VII collagen and AFs in RDEB patients. Gentamicin therapy may provide a readily available treatment for RDEB patients with nonsense mutations. TRIAL REGISTRATION. ClinicalTrials.gov NCT02698735. FUNDING. Epidermolysis Bullosa Research Partnership, Epidermolysis Bullosa Medical Research Foundation, NIH, and VA Merit Award.
Authors
David T. Woodley, Jon Cogan, Yingping Hou, Chao Lyu, M. Peter Marinkovich, Douglas Keene, Mei Chen
×Abstract
Current anti-VEGF therapies for colorectal cancer (CRC) provide limited survival benefit, as tumors rapidly develop resistance to these agents. Here, we have uncovered an immunosuppressive role for nonclassical Ly6Clo monocytes that mediates resistance to anti-VEGFR2 treatment. We found that the chemokine CX3CL1 was upregulated in both human and murine tumors following VEGF signaling blockade, resulting in recruitment of CX3CR1+Ly6Clo monocytes into the tumor. We also found that treatment with VEGFA reduced expression of CX3CL1 in endothelial cells in vitro. Intravital microscopy revealed that CX3CR1 is critical for Ly6Clo monocyte transmigration across the endothelium in murine CRC tumors. Moreover, Ly6Clo monocytes recruit Ly6G+ neutrophils via CXCL5 and produce IL-10, which inhibits adaptive immunity. Preventing Ly6Clo monocyte or Ly6G+ neutrophil infiltration into tumors enhanced inhibition of tumor growth with anti-VEGFR2 therapy. Furthermore, a gene therapy using a nanoparticle formulated with an siRNA against CX3CL1 reduced Ly6Clo monocyte recruitment and improved outcome of anti-VEGFR2 therapy in mouse CRCs. Our study unveils an immunosuppressive function of Ly6Clo monocytes that, to our knowledge, has yet to be reported in any context. We also reveal molecular mechanisms underlying antiangiogenic treatment resistance, suggesting potential immunomodulatory strategies to enhance the long-term clinical outcome of anti-VEGF therapies.
Authors
Keehoon Jung, Takahiro Heishi, Omar F. Khan, Piotr S. Kowalski, Joao Incio, Nuh N. Rahbari, Euiheon Chung, Jeffrey W. Clark, Christopher G. Willett, Andrew D. Luster, Seok Hyun Yun, Robert Langer, Daniel G. Anderson, Timothy P. Padera, Rakesh K. Jain, Dai Fukumura
×Abstract
BACKGROUND. Ibrutinib has been shown to have immunomodulatory effects by inhibiting Bruton’s tyrosine kinase (BTK) and IL-2–inducible T cell kinase (ITK). The relative importance of inhibiting these 2 kinases has not been examined despite its relevance to immune-based therapies. METHODS. Peripheral blood mononuclear cells from chronic lymphocytic leukemia (CLL) patients on clinical trials of ibrutinib (BTK/ITK inhibitor; n = 19) or acalabrutinib (selective BTK inhibitor; n = 13) were collected serially. T cell phenotype, immune function, and CLL cell immunosuppressive capacity were evaluated. RESULTS. Ibrutinib markedly increased CD4+ and CD8+ T cell numbers in CLL patients. This effect was more prominent in effector/effector memory subsets and was not observed with acalabrutinib. Ex vivo studies demonstrated that this may be due to diminished activation-induced cell death through ITK inhibition. PD-1 and CTLA-4 expression was significantly markedly reduced in T cells by both agents. While the number of Treg cells remained unchanged, the ratio of these to conventional CD4+ T cells was reduced with ibrutinib, but not acalabrutinib. Both agents reduced expression of the immunosuppressive molecules CD200 and BTLA as well as IL-10 production by CLL cells. CONCLUSIONS. Ibrutinib treatment increased the in vivo persistence of activated T cells, decreased the Treg/CD4+ T cell ratio, and diminished the immune-suppressive properties of CLL cells through BTK-dependent and -independent mechanisms. These features provide a strong rationale for combination immunotherapy approaches with ibrutinib in CLL and other cancers. TRIAL REGISTRATION. ClinicalTrials.gov NCT01589302 and NCT02029443. Samples described here were collected per OSU-0025. FUNDING. The National Cancer Institute.
Authors
Meixiao Long, Kyle Beckwith, Priscilla Do, Bethany L. Mundy, Amber Gordon, Amy M. Lehman, Kami J. Maddocks, Carolyn Cheney, Jeffrey A. Jones, Joseph M. Flynn, Leslie A. Andritsos, Farrukh Awan, Joseph A. Fraietta, Carl H. June, Marcela V. Maus, Jennifer A. Woyach, Michael A. Caligiuri, Amy J. Johnson, Natarajan Muthusamy, John C. Byrd
×Abstract
The lack of mechanistic explanations for many genotype-phenotype associations identified by GWAS precludes thorough assessment of their impact on human health. Here, we conducted an expression quantitative trait locus (eQTL) mapping analysis in erythroblasts and found erythroid-specific eQTLs for ATP2B4, the main calcium ATPase of red blood cells (rbc). The same SNPs were previously associated with mean corpuscular hemoglobin concentration (MCHC) and susceptibility to severe malaria infection. We showed that Atp2b4–/– mice demonstrate increased MCHC, confirming ATP2B4 as the causal gene at this GWAS locus. Using CRISPR-Cas9, we fine mapped the genetic signal to an erythroid-specific enhancer of ATP2B4. Erythroid cells with a deletion of the ATP2B4 enhancer had abnormally high intracellular calcium levels. These results illustrate the power of combined transcriptomic, epigenomic, and genome-editing approaches in characterizing noncoding regulatory elements in phenotype-relevant cells. Our study supports ATP2B4 as a potential target for modulating rbc hydration in erythroid disorders and malaria infection.
Authors
Samuel Lessard, Emily Stern Gatof, Mélissa Beaudoin, Patrick G. Schupp, Falak Sher, Adnan Ali, Sukhpal Prehar, Ryo Kurita, Yukio Nakamura, Esther Baena, Jonathan Ledoux, Delvac Oceandy, Daniel E. Bauer, Guillaume Lettre
×Abstract
Accumulating evidence suggests that glioma stem cells (GSCs) are important therapeutic targets in glioblastoma (GBM). In this study, we identified NIMA-related kinase 2 (NEK2) as a functional binding protein of enhancer of zeste homolog 2 (EZH2) that plays a critical role in the posttranslational regulation of EZH2 protein in GSCs. NEK2 was among the most differentially expressed kinase-encoding genes in GSC-containing cultures (glioma spheres), and it was required for in vitro clonogenicity, in vivo tumor propagation, and radioresistance. Mechanistically, the formation of a protein complex comprising NEK2 and EZH2 in glioma spheres phosphorylated and then protected EZH2 from ubiquitination-dependent protein degradation in a NEK2 kinase activity–dependent manner. Clinically, NEK2 expression in patients with glioma was closely associated with EZH2 expression and correlated with a poor prognosis. NEK2 expression was also substantially elevated in recurrent tumors after therapeutic failure compared with primary untreated tumors in matched GBM patients. We designed a NEK2 kinase inhibitor, compound 3a (CMP3a), which efficiently attenuated GBM growth in a mouse model and exhibited a synergistic effect with radiotherapy. These data demonstrate a key role for NEK2 in maintaining GSCs in GBM by stabilizing the EZH2 protein and introduce the small-molecule inhibitor CMP3a as a potential therapeutic agent for GBM.
Authors
Jia Wang, Peng Cheng, Marat S. Pavlyukov, Hai Yu, Zhuo Zhang, Sung-Hak Kim, Mutsuko Minata, Ahmed Mohyeldin, Wanfu Xie, Dongquan Chen, Violaine Goidts, Brendan Frett, Wenhao Hu, Hongyu Li, Yong Jae Shin, Yeri Lee, Do-Hyun Nam, Harley I. Kornblum, Maode Wang, Ichiro Nakano
×Abstract
BACKGROUND. The tumor immune response is increasingly associated with better clinical outcomes in breast and other cancers. However, the evaluation of tumor-infiltrating lymphocytes (TILs) relies on histopathological measurements with limited accuracy and reproducibility. Here, we profiled DNA methylation markers to identify a methylation of TIL (MeTIL) signature that recapitulates TIL evaluations and their prognostic value for long-term outcomes in breast cancer (BC). METHODS. MeTIL signature scores were correlated with clinical endpoints reflecting overall or disease-free survival and a pathologic complete response to preoperative anthracycline therapy in 3 BC cohorts from the Jules Bordet Institute in Brussels and in other cancer types from The Cancer Genome Atlas. RESULTS. The MeTIL signature measured TIL distributions in a sensitive manner and predicted survival and response to chemotherapy in BC better than did histopathological assessment of TILs or gene expression–based immune markers, respectively. The MeTIL signature also improved the prediction of survival in other malignancies, including melanoma and lung cancer. Furthermore, the MeTIL signature predicted differences in survival for malignancies in which TILs were not known to have a prognostic value. Finally, we showed that MeTIL markers can be determined by bisulfite pyrosequencing of small amounts of DNA from formalin-fixed, paraffin-embedded tumor tissue, supporting clinical applications for this methodology. CONCLUSIONS. This study highlights the power of DNA methylation to evaluate tumor immune responses and the potential of this approach to improve the diagnosis and treatment of breast and other cancers. FUNDING. This work was funded by the Fonds National de la Recherche Scientifique (FNRS) and Télévie, the INNOVIRIS Brussels Region BRUBREAST Project, the IUAP P7/03 program, the Belgian “Foundation against Cancer,” the Breast Cancer Research Foundation (BCRF), and the Fonds Gaston Ithier.
Authors
Jana Jeschke, Martin Bizet, Christine Desmedt, Emilie Calonne, Sarah Dedeurwaerder, Soizic Garaud, Alexander Koch, Denis Larsimont, Roberto Salgado, Gert Van den Eynden, Karen Willard Gallo, Gianluca Bontempi, Matthieu Defrance, Christos Sotiriou, François Fuks
×Abstract
Adipocytes secrete the hormone leptin to signal the sufficiency of energy stores. Reductions in circulating leptin concentrations reflect a negative energy balance, which augments sympathetic nervous system (SNS) activation in response to metabolically demanding emergencies. This process ensures adequate glucose mobilization despite low energy stores. We report that leptin receptor–expressing neurons (LepRb neurons) in the periaqueductal gray (PAG), the largest population of LepRb neurons in the brain stem, mediate this process. Application of noxious stimuli, which often signal the need to mobilize glucose to support an appropriate response, activated PAG LepRb neurons, which project to and activate parabrachial nucleus (PBN) neurons that control SNS activation and glucose mobilization. Furthermore, activating PAG LepRb neurons increased SNS activity and blood glucose concentrations, while ablating LepRb in PAG neurons augmented glucose mobilization in response to noxious stimuli. Thus, decreased leptin action on PAG LepRb neurons augments the autonomic response to noxious stimuli, ensuring sufficient glucose mobilization during periods of acute demand in the face of diminished energy stores.
Authors
Jonathan N. Flak, Deanna Arble, Warren Pan, Christa Patterson, Thomas Lanigan, Paulette B. Goforth, Jamie Sacksner, Maja Joosten, Donald A. Morgan, Margaret B. Allison, John Hayes, Eva Feldman, Randy J. Seeley, David P. Olson, Kamal Rahmouni, Martin G. Myers Jr.
×Abstract
After traumatic brain injury (TBI), glial cells have both beneficial and deleterious roles in injury progression and recovery. However, few studies have examined the influence of reactive astrocytes in the tripartite synapse following TBI. Here, we have demonstrated that hippocampal synaptic damage caused by controlled cortical impact (CCI) injury in mice results in a switch from neuronal to astrocytic d-serine release. Under nonpathological conditions, d-serine functions as a neurotransmitter and coagonist for NMDA receptors and is involved in mediating synaptic plasticity. The phasic release of neuronal d-serine is important in maintaining synaptic function, and deficiencies lead to reductions in synaptic function and plasticity. Following CCI injury, hippocampal neurons downregulated d-serine levels, while astrocytes enhanced production and release of d-serine. We further determined that this switch in the cellular source of d-serine, together with the release of basal levels of glutamate, contributes to synaptic damage and dysfunction. Astrocyte-specific elimination of the astrocytic d-serine–synthesizing enzyme serine racemase after CCI injury improved synaptic plasticity, brain oscillations, and learning behavior. We conclude that the enhanced tonic release of d-serine from astrocytes after TBI underlies much of the synaptic damage associated with brain injury.
Authors
Enmanuel J. Perez, Stephen A. Tapanes, Zachary B. Loris, Darrick T. Balu, Thomas J. Sick, Joseph T. Coyle, Daniel J. Liebl
×Abstract
BACKGROUND. The histone deacetylase (HDAC) inhibitor vorinostat (VOR) can increase HIV RNA expression in vivo within resting CD4+ T cells of aviremic HIV+ individuals. However, while studies of VOR or other HDAC inhibitors have reported reversal of latency, none has demonstrated clearance of latent infection. We sought to identify the optimal dosing of VOR for effective serial reversal of HIV latency. METHODS. In a study of 16 HIV-infected, aviremic individuals, we measured resting CD4+ T cell–associated HIV RNA ex vivo and in vivo following a single exposure to VOR, and then in vivo after a pair of doses separated by 48 or 72 hours, and finally following a series of 10 doses given at 72-hour intervals. RESULTS. Serial VOR exposures separated by 72 hours most often resulted in an increase in cell-associated HIV RNA within circulating resting CD4+ T cells. VOR was well tolerated by all participants. However, despite serial reversal of latency over 1 month of VOR dosing, we did not observe a measurable decrease (>0.3 log10) in the frequency of latent infection within resting CD4+ T cells. CONCLUSIONS. These findings outline parameters for the experimental use of VOR to clear latent infection. Latency reversal can be achieved by VOR safely and repeatedly, but effective depletion of persistent HIV infection will require additional advances. In addition to improvements in latency reversal, these advances may include the sustained induction of potent antiviral immune responses capable of recognizing and clearing the rare cells in which HIV latency has been reversed. TRIAL REGISTRATION. Clinicaltrials.gov NCT01319383. FUNDING. NIH grants U01 AI095052, AI50410, and P30 CA016086 and National Center for Advancing Translational Sciences grant KL2 TR001109.
Authors
Nancie M. Archin, Jennifer L. Kirchherr, Julia A.M. Sung, Genevieve Clutton, Katherine Sholtis, Yinyan Xu, Brigitte Allard, Erin Stuelke, Angela D. Kashuba, Joann D. Kuruc, Joseph Eron, Cynthia L. Gay, Nilu Goonetilleke, David M. Margolis
×Abstract
Lesions and neurologic disability in inflammatory CNS diseases such as multiple sclerosis (MS) result from the translocation of leukocytes and humoral factors from the vasculature, first across the endothelial blood-brain barrier (BBB) and then across the astrocytic glia limitans (GL). Factors secreted by reactive astrocytes open the BBB by disrupting endothelial tight junctions (TJs), but the mechanisms that control access across the GL are unknown. Here, we report that in inflammatory lesions, a second barrier composed of reactive astrocyte TJs of claudin 1 (CLDN1), CLDN4, and junctional adhesion molecule A (JAM-A) subunits is induced at the GL. In a human coculture model, CLDN4-deficient astrocytes were unable to control lymphocyte segregation. In models of CNS inflammation and MS, mice with astrocyte-specific Cldn4 deletion displayed exacerbated leukocyte and humoral infiltration, neuropathology, motor disability, and mortality. These findings identify a second inducible barrier to CNS entry at the GL. This barrier may be therapeutically targetable in inflammatory CNS disease.
Authors
Sam Horng, Anthony Therattil, Sarah Moyon, Alexandra Gordon, Karla Kim, Azeb Tadesse Argaw, Yuko Hara, John N. Mariani, Setsu Sawai, Per Flodby, Edward D. Crandall, Zea Borok, Michael V. Sofroniew, Candice Chapouly, Gareth R. John
×Abstract
Obesity promotes a chronic inflammatory and hypercoagulable state that drives cardiovascular disease, type 2 diabetes, fatty liver disease, and several cancers. Elevated thrombin activity underlies obesity-linked thromboembolic events, but the mechanistic links between the thrombin/fibrin(ogen) axis and obesity-associated pathologies are incompletely understood. In this work, immunohistochemical studies identified extravascular fibrin deposits within white adipose tissue and liver as distinct features of mice fed a high-fat diet (HFD) as well as obese patients. Fibγ390–396A mice carrying a mutant form of fibrinogen incapable of binding leukocyte αMβ2-integrin were protected from HFD-induced weight gain and elevated adiposity. Fibγ390–396A mice had markedly diminished systemic, adipose, and hepatic inflammation with reduced macrophage counts within white adipose tissue, as well as near-complete protection from development of fatty liver disease and glucose dysmetabolism. Homozygous thrombomodulin-mutant ThbdPro mice, which have elevated thrombin procoagulant function, gained more weight and developed exacerbated fatty liver disease when fed a HFD compared with WT mice. In contrast, treatment with dabigatran, a direct thrombin inhibitor, limited HFD-induced obesity development and suppressed progression of sequelae in mice with established obesity. Collectively, these data provide proof of concept that targeting thrombin or fibrin(ogen) may limit pathologies in obese patients.
Authors
Anna K. Kopec, Sara R. Abrahams, Sherry Thornton, Joseph S. Palumbo, Eric S. Mullins, Senad Divanovic, Hartmut Weiler, A. Phillip Owens III, Nigel Mackman, Ashley Goss, Joanne van Ryn, James P. Luyendyk, Matthew J. Flick
×Abstract
Proinflammatory leukotrienes (LTs) are produced by 5-lipoxygenase (5-LO) aided by 5-LO–activating protein (FLAP). LT biosynthesis inhibitors are currently under clinical investigation as treatments for respiratory and cardiovascular diseases. Here, we have revealed a sex bias in the efficiency of clinically relevant LT biosynthesis inhibitors, showing that their effects are superior in females. We found that androgens cause these sex differences by impeding the LT-biosynthetic 5-LO/FLAP complex assembly. Lower doses of the FLAP inhibitor MK886 were required to reduce LTB4 levels in exudates of female versus male mice and rats. Following platelet-activating factor–induced shock, MK886 increased survival exclusively in female mice, and this effect was abolished by testosterone administration. FLAP inhibitors and the novel-type 5-LO inhibitors licofelone and sulindac sulfide exhibited higher potencies in human blood from females, and bioactive 5-LO/FLAP complexes were formed in female, but not male, human and murine leukocytes. Supplementation of female blood or leukocytes with 5α-dihydrotestosterone abolished the observed sex differences. Our data suggest that females may benefit from anti-LT therapy to a greater extent than males, prompting consideration of sex issues in LT modifier development.
Authors
Simona Pace, Carlo Pergola, Friederike Dehm, Antonietta Rossi, Jana Gerstmeier, Fabiana Troisi, Helmut Pein, Anja M. Schaible, Christina Weinigel, Silke Rummler, Hinnak Northoff, Stefan Laufer, Thorsten J. Maier, Olof Rådmark, Bengt Samuelsson, Andreas Koeberle, Lidia Sautebin, Oliver Werz
×Abstract
Adoptive transfer of T cells engineered to express a hepatitis B virus–specific (HBV-specific) T cell receptor (TCR) may supplement HBV-specific immune responses in chronic HBV patients and facilitate HBV control. However, the risk of triggering unrestrained proliferation of permanently engineered T cells raises safety concerns that have hampered testing of this approach in patients. The aim of the present study was to generate T cells that transiently express HBV-specific TCRs using mRNA electroporation and to assess their antiviral and pathogenetic activity in vitro and in HBV-infected human liver chimeric mice. We assessed virological and gene-expression changes using quantitative reverse-transcriptase PCR (qRT-PCR), immunofluorescence, and Luminex technology. HBV-specific T cells lysed HBV-producing hepatoma cells in vitro. In vivo, 3 injections of HBV-specific T cells caused progressive viremia reduction within 12 days of treatment in animals reconstituted with haplotype-matched hepatocytes, whereas viremia remained stable in mice receiving irrelevant T cells redirected toward hepatitis C virus–specific TCRs. Notably, increases in alanine aminotransferase levels, apoptotic markers, and human inflammatory cytokines returned to pretreatment levels within 9 days after the last injection. T cell transfer did not trigger inflammation in uninfected mice. These data support the feasibility of using mRNA electroporation to engineer HBV TCR–redirected T cells in patients with chronic HBV infection.
Authors
Janine Kah, Sarene Koh, Tassilo Volz, Erica Ceccarello, Lena Allweiss, Marc Lütgehetmann, Antonio Bertoletti, Maura Dandri
×Abstract
Defective protein quality control (PQC) systems are implicated in multiple diseases. Molecular chaperones and co-chaperones play a central role in functioning PQC. Constant mechanical and metabolic stress in cardiomyocytes places great demand on the PQC system. Mutation and downregulation of the co-chaperone protein BCL-2–associated athanogene 3 (BAG3) are associated with cardiac myopathy and heart failure, and a BAG3 E455K mutation leads to dilated cardiomyopathy (DCM). However, the role of BAG3 in the heart and the mechanisms by which the E455K mutation leads to DCM remain obscure. Here, we found that cardiac-specific Bag3-KO and E455K-knockin mice developed DCM. Comparable phenotypes in the 2 mutants demonstrated that the E455K mutation resulted in loss of function. Further experiments revealed that the E455K mutation disrupted the interaction between BAG3 and HSP70. In both mutants, decreased levels of small heat shock proteins (sHSPs) were observed, and a subset of proteins required for cardiomyocyte function was enriched in the insoluble fraction. Together, these observations suggest that interaction between BAG3 and HSP70 is essential for BAG3 to stabilize sHSPs and maintain cardiomyocyte protein homeostasis. Our results provide insight into heart failure caused by defects in BAG3 pathways and suggest that increasing BAG3 protein levels may be of therapeutic benefit in heart failure.
Authors
Xi Fang, Julius Bogomolovas, Tongbin Wu, Wei Zhang, Canzhao Liu, Jennifer Veevers, Matthew J. Stroud, Zhiyuan Zhang, Xiaolong Ma, Yongxin Mu, Dieu-Hung Lao, Nancy D. Dalton, Yusu Gu, Celine Wang, Michael Wang, Yan Liang, Stephan Lange, Kunfu Ouyang, Kirk L. Peterson, Sylvia M. Evans, Ju Chen
Copyright © 2024 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)