Issue published February 3, 2020 Previous issue | Next issue
- Volume 130, Issue 2
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On the cover: Big data's future in medicine
Massive amounts of health care data can be gleaned from patient health records, pharmacies, clinical trials, insurance providers, regulatory bodies, hospitals and clinics, wearables and sensors, and more. This month in the JCI, a series of Reviews describes how large-scale data sets can provide valuable insights that help personalize the treatment of disease, diagnose and understand rare diseases, optimize clinical trial design, facilitate drug discovery and development, reduce health care costs, and more. This issue’s cover is a playful representation of the complex networks that visualize meaningful connections in large-scale data sets, such as multiomics analyses.
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Review Series
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Abstract
Real-world data (RWD) continue to emerge as a new source of clinical evidence. Although the best-known use case of RWD has been in drug regulation, RWD are being generated and used by many other parties, including biopharmaceutical companies, payors, clinical researchers, providers, and patients. In this Review, we describe 21 potential uses for RWD across the spectrum of health care. We also discuss important challenges and limitations relevant to the translation of these data into evidence.
Authors
Vivek A. Rudrapatna, Atul J. Butte
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Technological advances in rapid data acquisition have transformed medical biology into a data mining field, where new data sets are routinely dissected and analyzed by statistical models of ever-increasing complexity. Many hypotheses can be generated and tested within a single large data set, and even small effects can be statistically discriminated from a sea of noise. On the other hand, the development of therapeutic interventions moves at a much slower pace. They are determined from carefully randomized and well-controlled experiments with explicitly stated outcomes as the principal mechanism by which a single hypothesis is tested. In this paradigm, only a small fraction of interventions can be tested, and an even smaller fraction are ultimately deemed therapeutically successful. In this Review, we propose strategies to leverage large-cohort data to inform the selection of targets and the design of randomized trials of novel therapeutics. Ultimately, the incorporation of big data and experimental medicine approaches should aim to reduce the failure rate of clinical trials as well as expedite and lower the cost of drug development.
Authors
Eugene Melamud, D. Leland Taylor, Anurag Sethi, Madeleine Cule, Anastasia Baryshnikova, Danish Saleheen, Nick van Bruggen, Garret A. FitzGerald
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Review
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Abstract
Signaling by the TGF-β superfamily is important in the regulation of hematopoiesis and is dysregulated in myelodysplastic syndromes (MDSs), contributing to ineffective hematopoiesis and clinical cytopenias. TGF-β, activins, and growth differentiation factors exert inhibitory effects on red cell formation by activating canonical SMAD2/3 pathway signaling. In this Review, we summarize evidence that overactivation of SMAD2/3 signaling pathways in MDSs causes anemia due to impaired erythroid maturation. We also describe the basis for biological activity of activin receptor ligand traps, novel fusion proteins such as luspatercept that are promising as erythroid maturation agents to alleviate anemia and related comorbidities in MDSs and other conditions characterized by impaired erythroid maturation.
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Amit Verma, Rajasekhar N.V.S. Suragani, Srinivas Aluri, Nishi Shah, Tushar D. Bhagat, Mark J. Alexander, Rami Komrokji, Ravi Kumar
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Commentaries
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Abstract
Although iron deficiency continues to pose a problem for pregnant women and fetal development, an incomplete understanding of placental adaptation to limited iron availability has hindered efforts to identify optimal supplementation strategies. In this issue of the JCI, Sangkhae et al. used mouse models and human placentas to explore maternal, placental, and fetal responses to alterations in iron status during pregnancy. The authors identified molecular mechanisms that limit placental ability to upregulate iron transport in the setting of severe iron deficiency and explored a potential marker of placental maladaptation.
Authors
Nermi L. Parrow, Robert E. Fleming
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KBTBD13 is a protein expressed in striated muscle whose precise function is unknown. Work by de Winter et al. in this issue of the JCI provides evidence that KBTBD13 localizes to the sarcomere and can directly bind actin. A mutation in KBTBD13 that is associated with nemaline myopathy alters the protein’s effects on actin, apparently increasing thin-filament stiffness and ultimately depressing contractile force and relaxation rate. We discuss here the implications of this new sarcomeric protein, some alternate explanations for the effects of KBTBD13R408C, and the advantages of using computational models to interpret functional data from muscle.
Authors
Stuart G. Campbell, Steven A. Niederer
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Liver disease as a result of chronic hepatitis C virus (HCV) infection is a global problem. While some HCV infections resolve spontaneously, viral persistence associates with compromised T cell immunity. In this issue of the JCI, Chen et al. and Coss et al. explored virus-specific CD4+ T cell response during HCV infection. Both studies evaluated the HCV-specific T cells of patients with different courses of infection. Chen et al. revealed that initial CD4+ T cell responses are similar during early infection and that T cell failure resulted from loss of the virus-specific T cells themselves. Coss et al. showed that HCV-specific CD4+ T cells temporarily recovered in some women following childbirth. These studies contribute to our understanding of CD4+ T cell functionality during different natural courses of infection, with the notable implication that restoring CD4+ T cell immunity might contribute to controlling HCV infection.
Authors
Benedikt Binder, Robert Thimme
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Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease in China, South Korea, and Japan caused by the tick-borne SFTS virus (SFTSV). Severe and fatal SFTS presents as a hemorrhagic fever characterized by high viral load, uncontrolled inflammatory response, dysregulated adaptive immunity, coagulation abnormalities, hemorrhage, and multiorgan failure with up to 33% case fatality rates (CFRs). Despite its public health significance in Asia, vaccines and specific therapeutics against SFTS are still unavailable. A better understanding of the pathogenesis of SFTS is crucial to improving medical countermeasures against this devastating disease. In this issue of the JCI, Suzuki and colleagues analyzed histopathological samples from 22 individuals who succumbed to SFTS, and identified antibody-producing B cell–lineage plasmablasts and macrophages as principal target cells for SFTSV infection in fatal SFTS. Their results suggest that SFTSV-infected post–germinal center B cells, plasmablasts, and macrophages affect systemic immunopathology and dysregulation, which likely leads to fatal outcomes.
Authors
Satoko Yamaoka, Carla Weisend, Hideki Ebihara
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Parkinson’s disease (PD) is a neurodegenerative disease caused by the progressive loss of dopaminergic (DA) neurons in the midbrain projecting to the striatum, which leads to motor dysfunctions, such as bradykinesia (slowed movement), rigidity, and tremors. To replace the lost cells, the transplantation of DA neurons derived from embryonic stem cells or induced pluripotent stem cells (iPSCs) has been considered. In this issue of the JCI, Song et al. report on their development of an iPSC induction and differentiation protocol that can promote the realization of autologous transplantation to treat PD patients with their own cells.
Authors
Jun Takahashi
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Asthma is a common chronic respiratory disease that has a heritable component. Polymorphisms in the endoplasmic reticular protein orosomucoid-like protein 3 (ORMDL3), which regulates sphingolipid homeostasis, have been strongly linked with childhood-onset asthma. Despite extensive investigation, a link between ORMDL3 asthma–risk genotypes and altered sphingolipid synthesis has been lacking. In this issue of the JCI, Ono et al. establish a clear association between nonallergic childhood asthma, lower whole-blood sphingolipids, and asthma-risk 17q21 genotypes. These results demonstrate that genetic variants in ORMDL3 may confer a risk of developing childhood asthma through dysregulation of sphingolipid synthesis. As such, modulation of sphingolipids may represent a promising avenue of therapeutic development for childhood asthma.
Authors
Marsha Wills-Karp
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The advent of human induced pluripotent stem cells (iPSCs) provided a means for avoiding ethical concerns associated with the use of cells isolated from human embryos. The number of labs now using iPSCs to generate photoreceptor, retinal pigmented epithelial (RPE), and—more recently—choroidal endothelial cells has grown exponentially. However, for autologous cell replacement to be effective, manufacturing strategies will need to change. Many tasks carried out by hand will need simplifying and automating. In this issue of the JCI, Schaub and colleagues combined quantitative bright-field microscopy and artificial intelligence (deep neural networks and traditional machine learning) to noninvasively monitor iPSC-derived graft maturation, predict donor cell identity, and evaluate graft function prior to transplantation. This approach allowed the authors to preemptively identify and remove abnormal grafts. Notably, the method is (a) transferable, (b) cost and time effective, (c) high throughput, and (d) useful for primary product validation.
Authors
Budd A. Tucker, Robert F. Mullins, Edwin M. Stone
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Research Articles
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Abstract
Iron deficiency is common worldwide and is associated with adverse pregnancy outcomes. The increasing prevalence of indiscriminate iron supplementation during pregnancy also raises concerns about the potential adverse effects of iron excess. We examined how maternal iron status affects the delivery of iron to the placenta and fetus. Using mouse models, we documented maternal homeostatic mechanisms that protect the placenta and fetus from maternal iron excess. We determined that under physiological conditions or in iron deficiency, fetal and placental hepcidin did not regulate fetal iron endowment. With maternal iron deficiency, critical transporters mediating placental iron uptake (transferrin receptor 1 [TFR1]) and export (ferroportin [FPN]) were strongly regulated. In mice, not only was TFR1 increased, but FPN was surprisingly decreased to preserve placental iron in the face of fetal iron deficiency. In human placentas from pregnancies with mild iron deficiency, TFR1 was increased, but there was no change in FPN. However, induction of more severe iron deficiency in human trophoblast in vitro resulted in the regulation of both TFR1 and FPN, similar to what was observed in the mouse model. This placental adaptation that prioritizes placental iron is mediated by iron regulatory protein 1 (IRP1) and is important for the maintenance of mitochondrial respiration, thus ultimately protecting the fetus from the potentially dire consequences of generalized placental dysfunction.
Authors
Veena Sangkhae, Allison L. Fisher, Shirley Wong, Mary Dawn Koenig, Lisa Tussing-Humphreys, Alison Chu, Melisa Lelić, Tomas Ganz, Elizabeta Nemeth
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EGFR-mutated lung adenocarcinoma patients treated with gefitinib and osimertinib show a therapeutic benefit limited by the appearance of secondary mutations, such as EGFRT790M and EGFRC797S. It is generally assumed that these secondary mutations render EGFR completely unresponsive to the inhibitors, but contrary to this, we uncovered here that gefitinib and osimertinib increased STAT3 phosphorylation (p-STAT3) in EGFRT790M and EGFRC797S tumoral cells. Interestingly, we also found that concomitant Notch inhibition with gefitinib or osimertinib treatment induced a p-STAT3–dependent strong reduction in the levels of the transcriptional repressor HES1. Importantly, we showed that tyrosine kinase inhibitor–resistant tumors, with EGFRT790M and EGFRC797S mutations, were highly responsive to the combined treatment of Notch inhibitors with gefitinib or osimertinib, respectively. Finally, in patients with EGFR mutations treated with tyrosine kinase inhibitors, HES1 protein levels increased during relapse and correlated with shorter progression-free survival. Therefore, our results offer a proof of concept for an alternative treatment to chemotherapy in lung adenocarcinoma osimertinib-treated patients after disease progression.
Authors
Emilie Bousquet Mur, Sara Bernardo, Laura Papon, Maicol Mancini, Eric Fabbrizio, Marion Goussard, Irene Ferrer, Anais Giry, Xavier Quantin, Jean-Louis Pujol, Olivier Calvayrac, Herwig P. Moll, Yaël Glasson, Nelly Pirot, Andrei Turtoi, Marta Cañamero, Kwok-Kin Wong, Yosef Yarden, Emilio Casanova, Jean-Charles Soria, Jacques Colinge, Christian W. Siebel, Julien Mazieres, Gilles Favre, Luis Paz-Ares, Antonio Maraver
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Pituitary develops from oral ectoderm in contact with adjacent ventral hypothalamus. Impairment in this process results in congenital pituitary hypoplasia (CPH); however, there have been no human disease models for CPH thus far, prohibiting the elucidation of the underlying mechanisms. In this study, we established a disease model of CPH using patient-derived induced pluripotent stem cells (iPSCs) and 3D organoid technique, in which oral ectoderm and hypothalamus develop simultaneously. Interestingly, patient iPSCs with a heterozygous mutation in the orthodenticle homeobox 2 (OTX2) gene showed increased apoptosis in the pituitary progenitor cells, and the differentiation into pituitary hormone–producing cells was severely impaired. As an underlying mechanism, OTX2 in hypothalamus, not in oral ectoderm, was essential for progenitor cell maintenance by regulating LHX3 expression in oral ectoderm via FGF10 expression in the hypothalamus. Convincingly, the phenotype was reversed by the correction of the mutation, and the haploinsufficiency of OTX2 in control iPSCs revealed a similar phenotype, demonstrating that this mutation was responsible. Thus, we established an iPSC-based congenital pituitary disease model, which recapitulated interaction between hypothalamus and oral ectoderm and demonstrated the essential role of hypothalamic OTX2.
Authors
Ryusaku Matsumoto, Hidetaka Suga, Takashi Aoi, Hironori Bando, Hidenori Fukuoka, Genzo Iguchi, Satoshi Narumi, Tomonobu Hasegawa, Keiko Muguruma, Wataru Ogawa, Yutaka Takahashi
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Tuberculosis (TB) remains a major infectious disease worldwide. TB treatment displays a biphasic bacterial clearance, in which the majority of bacteria clear within the first month of treatment, but residual bacteria remain nonresponsive to treatment and eventually may become resistant. Here, we have shown that Mycobacterium tuberculosis was taken up by mesenchymal stem cells (MSCs), where it established dormancy and became highly nonresponsive to isoniazid, a major constituent of directly observed treatment short course (DOTS). Dormant M. tuberculosis induced quiescence in MSCs and promoted their long-term survival. Unlike macrophages, where M. tuberculosis resides in early-phagosomal compartments, in MSCs the majority of bacilli were found in the cytosol, where they promoted rapid lipid synthesis, hiding within lipid droplets. Inhibition of lipid synthesis prevented dormancy and sensitized the organisms to isoniazid. Thus, we have established that M. tuberculosis gains dormancy in MSCs, which serve as a long-term natural reservoir of dormant M. tuberculosis. Interestingly, in the murine model of TB, induction of autophagy eliminated M. tuberculosis from MSCs, and consequently, the addition of rapamycin to an isoniazid treatment regimen successfully attained sterile clearance and prevented disease reactivation.
Authors
Samreen Fatima, Shashank Shivaji Kamble, Ved Prakash Dwivedi, Debapriya Bhattacharya, Santosh Kumar, Anand Ranganathan, Luc Van Kaer, Sujata Mohanty, Gobardhan Das
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Seasonal and pandemic influenza infection remains a major public health concern worldwide. Driving robust humoral immunity has been a challenge given preexisting, often cross-reactive, immunity and in particular, poorly immunogenic avian antigens. To overcome immune barriers, the adjuvant MF59 has been used in seasonal influenza vaccines to increase antibody titers and improve neutralizing activity, translating to a moderate increase in protection in vulnerable populations. However, its effects on stimulating antibody effector functions, including NK cell activation, monocyte phagocytosis, and complement activity, all of which have been implicated in protection against influenza, have yet to be defined. Using systems serology, we assessed changes in antibody functional profiles in individuals who received H5N1 avian influenza vaccine administered with MF59, with alum, or delivered unadjuvanted. MF59 elicited antibody responses that stimulated robust neutrophil phagocytosis and complement activity. Conversely, vaccination with MF59 recruited NK cells poorly and drove moderate monocyte phagocytic activity, both likely compromised because of the induction of antibodies that did not bind FCGR3A. Collectively, defining the humoral antibody functions induced by distinct adjuvants may provide a path to designing next-generation vaccines that can selectively leverage the humoral immune functions, beyond binding and neutralization, resulting in better protection from infection.
Authors
Carolyn M. Boudreau, Wen-Han Yu, Todd J. Suscovich, H. Keipp Talbot, Kathryn M. Edwards, Galit Alter
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Chimeric antigen receptor–engineered T cells targeting CD19 (CART19) provide an effective treatment for pediatric acute lymphoblastic leukemia but are less effective for chronic lymphocytic leukemia (CLL), focusing attention on improving efficacy. CART19 harbor an engineered receptor, which is delivered through lentiviral vector integration, thereby marking cell lineages and modifying the cellular genome by insertional mutagenesis. We recently reported that vector integration within the host TET2 gene was associated with CLL remission. Here, we investigated clonal population structure and therapeutic outcomes in another 39 patients by high-throughput sequencing of vector-integration sites. Genes at integration sites enriched in responders were commonly found in cell-signaling and chromatin modification pathways, suggesting that insertional mutagenesis in these genes promoted therapeutic T cell proliferation. We also developed a multivariate model based on integration-site distributions and found that data from preinfusion products forecasted response in CLL successfully in discovery and validation cohorts and, in day 28 samples, reported responders to CLL therapy with high accuracy. These data clarify how insertional mutagenesis can modulate cell proliferation in CART19 therapy and how data on integration-site distributions can be linked to treatment outcomes.
Authors
Christopher L. Nobles, Scott Sherrill-Mix, John K. Everett, Shantan Reddy, Joseph A. Fraietta, David L. Porter, Noelle Frey, Saar I. Gill, Stephan A. Grupp, Shannon L. Maude, Donald L. Siegel, Bruce L. Levine, Carl H. June, Simon F. Lacey, J. Joseph Melenhorst, Frederic D. Bushman
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Vascular Ehlers-Danlos syndrome (vEDS) is an autosomal-dominant connective tissue disorder caused by heterozygous mutations in the COL3A1 gene, which encodes the pro-α 1 chain of collagen III. Loss of structural integrity of the extracellular matrix is believed to drive the signs and symptoms of this condition, including spontaneous arterial dissection and/or rupture, the major cause of mortality. We created 2 mouse models of vEDS that carry heterozygous mutations in Col3a1 that encode glycine substitutions analogous to those found in patients, and we showed that signaling abnormalities in the PLC/IP3/PKC/ERK pathway (phospholipase C/inositol 1,4,5-triphosphate/protein kinase C/extracellular signal–regulated kinase) are major mediators of vascular pathology. Treatment with pharmacologic inhibitors of ERK1/2 or PKCβ prevented death due to spontaneous aortic rupture. Additionally, we found that pregnancy- and puberty-associated accentuation of vascular risk, also seen in vEDS patients, was rescued by attenuation of oxytocin and androgen signaling, respectively. Taken together, our results provide evidence that targetable signaling abnormalities contribute to the pathogenesis of vEDS, highlighting unanticipated therapeutic opportunities.
Authors
Caitlin J. Bowen, Juan Francisco Calderón Giadrosic, Zachary Burger, Graham Rykiel, Elaine C. Davis, Mark R. Helmers, Kelly Benke, Elena Gallo MacFarlane, Harry C. Dietz
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HSP27 is highly expressed in, and supports oncogene addiction of, many cancers. HSP27 phosphorylation is a limiting step for activation of this protein and a target for inhibition, but its highly disordered structure challenges rational structure-guided drug discovery. We performed multistep biochemical, structural, and computational experiments to define a spherical 24-monomer complex composed of 12 HSP27 dimers with a phosphorylation pocket flanked by serine residues between their N-terminal domains. Ivermectin directly binds this pocket to inhibit MAPKAP2-mediated HSP27 phosphorylation and depolymerization, thereby blocking HSP27-regulated survival signaling and client-oncoprotein interactions. Ivermectin potentiated activity of anti–androgen receptor and anti-EGFR drugs in prostate and EGFR/HER2-driven tumor models, respectively, identifying a repurposing approach for cotargeting stress-adaptive responses to overcome resistance to inhibitors of oncogenic pathway signaling.
Authors
Lucia Nappi, Adeleke H. Aguda, Nader Al Nakouzi, Barbara Lelj-Garolla, Eliana Beraldi, Nada Lallous, Marisa Thi, Susan Moore, Ladan Fazli, Dulguun Battsogt, Sophie Stief, Fuqiang Ban, Nham T. Nguyen, Neetu Saxena, Evgenia Dueva, Fan Zhang, Takeshi Yamazaki, Amina Zoubeidi, Artem Cherkasov, Gary D. Brayer, Martin Gleave
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Although the impact of Th17 cells on autoimmunity is undisputable, their pathogenic effector mechanism is still enigmatic. We discovered soluble N-ethylmaleimide–sensitive factor attachment receptor (SNARE) complex proteins in Th17 cells that enable a vesicular glutamate release pathway that induces local intracytoplasmic calcium release and subsequent damage in neurons. This pathway is glutamine dependent and triggered by binding of β1-integrin to vascular cell adhesion molecule 1 (VCAM-1) on neurons in the inflammatory context. Glutamate secretion could be blocked by inhibiting either glutaminase or KV1.3 channels, which are known to be linked to integrin expression and highly expressed on stimulated T cells. Although KV1.3 is not expressed in CNS tissue, intrathecal administration of a KV1.3 channel blocker or a glutaminase inhibitor ameliorated disability in experimental neuroinflammation. In humans, T cells from patients with multiple sclerosis secreted higher levels of glutamate, and cerebrospinal fluid glutamine levels were increased. Altogether, our findings demonstrate that β1-integrin– and KV1.3 channel–dependent signaling stimulates glutamate release from Th17 cells upon direct cell-cell contact between Th17 cells and neurons.
Authors
Katharina Birkner, Beatrice Wasser, Tobias Ruck, Carine Thalman, Dirk Luchtman, Katrin Pape, Samantha Schmaul, Lynn Bitar, Eva-Maria Krämer-Albers, Albrecht Stroh, Sven G. Meuth, Frauke Zipp, Stefan Bittner
×Abstract
BACKGROUND Adoptive transfer of donor-derived EBV-specific cytotoxic T-lymphocytes (EBV-CTLs) can eradicate EBV-associated lymphomas (EBV-PTLD) after transplantation of hematopoietic cell (HCT) or solid organ (SOT) but is unavailable for most patients.METHODS We developed a third-party, allogeneic, off-the-shelf bank of 330 GMP-grade EBV-CTL lines from specifically consented healthy HCT donors. We treated 46 recipients of HCT (n = 33) or SOT (n = 13) with established EBV-PTLD, who had failed rituximab therapy, with third-party EBV-CTLs. Treatment cycles consisted of 3 weekly infusions of EBV-CTLs and 3 weeks of observation.RESULTS EBV-CTLs did not induce significant toxicities. One patient developed grade I skin graft-versus-host disease. Complete remission (CR) or sustained partial remission (PR) was achieved in 68% of HCT recipients and 54% of SOT recipients. For patients who achieved CR/PR or stable disease after cycle 1, one year overall survival was 88.9% and 81.8%, respectively. In addition, 3 of 5 recipients with POD after a first cycle who received EBV-CTLs from a different donor achieved CR or durable PR (60%) and survived longer than 1 year. Maximal responses were achieved after a median of 2 cycles.CONCLUSION Third-party EBV-CTLs of defined HLA restriction provide safe, immediately accessible treatment for EBV-PTLD. Secondary treatment with EBV-CTLs restricted by a different HLA allele (switch therapy) can also induce remissions if initial EBV-CTLs are ineffective. These results suggest a promising potential therapy for patients with rituximab-refractory EBV-associated lymphoma after transplantation.TRIAL REGISTRATION Phase II protocols (NCT01498484 and NCT00002663) were approved by the Institutional Review Board at Memorial Sloan Kettering Cancer Center, the FDA, and the National Marrow Donor Program.FUNDING This work was supported by NIH grants CA23766 and R21CA162002, the Aubrey Fund, the Claire Tow Foundation, the Major Family Foundation, the Max Cure Foundation, the Richard “Rick” J. Eisemann Pediatric Research Fund, the Banbury Foundation, the Edith Robertson Foundation, and the Larry Smead Foundation. Atara Biotherapeutics licensed the bank of third-party EBV-CTLs from Memorial Sloan Kettering Cancer Center in June 2015.
Authors
Susan Prockop, Ekaterina Doubrovina, Stephanie Suser, Glenn Heller, Juliet Barker, Parastoo Dahi, Miguel A. Perales, Esperanza Papadopoulos, Craig Sauter, Hugo Castro-Malaspina, Farid Boulad, Kevin J. Curran, Sergio Giralt, Boglarka Gyurkocza, Katharine C. Hsu, Ann Jakubowski, Alan M. Hanash, Nancy A. Kernan, Rachel Kobos, Guenther Koehne, Heather Landau, Doris Ponce, Barbara Spitzer, James W. Young, Gerald Behr, Mark Dunphy, Sofia Haque, Julie Teruya-Feldstein, Maria Arcila, Christine Moung, Susan Hsu, Aisha Hasan, Richard J. O’Reilly
×Abstract
Chronic hepatitis C virus (HCV) infection is characterized by persistent high-level viremia and defective cellular immunity, including a lack of functional HCV-specific CD4+ T cells. We previously described an exceptional period of viral control that occurs in some chronically infected women after childbirth. Here, we investigated whether reduced HCV replication after pregnancy is associated with recovery of CD4+ T cell immunity. Class II tetramer analysis revealed significantly greater frequencies of circulating HCV-specific CD4+ T cells at 3 months postpartum in women with concurrent declines in viremia compared with those with stable viremia. These HCV-specific CD4+ T cells had an effector-memory phenotype. Inhibitory coreceptor expression on these cells corresponded to the degree of viral control. Circulating CD4+ T cells produced IL-2 and IFN-γ after HCV antigen stimulation, demonstrating Th1 functionality. These data provide direct evidence that the profound loss of HCV-specific CD4+ T cell help that results in chronic infection is reversible following pregnancy, and this recovery of CD4+ T cells is associated with at least transient control of persistent viral replication.
Authors
Samantha L. Coss, Almudena Torres-Cornejo, Mona R. Prasad, Melissa Moore-Clingenpeel, Arash Grakoui, Georg M. Lauer, Christopher M. Walker, Jonathan R. Honegger
×Abstract
The mechanisms that modulate the kinetics of muscle relaxation are critically important for muscle function. A prime example of the impact of impaired relaxation kinetics is nemaline myopathy caused by mutations in KBTBD13 (NEM6). In addition to weakness, NEM6 patients have slow muscle relaxation, compromising contractility and daily life activities. The role of KBTBD13 in muscle is unknown, and the pathomechanism underlying NEM6 is undetermined. A combination of transcranial magnetic stimulation–induced muscle relaxation, muscle fiber– and sarcomere-contractility assays, low-angle x-ray diffraction, and superresolution microscopy revealed that the impaired muscle-relaxation kinetics in NEM6 patients are caused by structural changes in the thin filament, a sarcomeric microstructure. Using homology modeling and binding and contractility assays with recombinant KBTBD13, Kbtbd13-knockout and Kbtbd13R408C-knockin mouse models, and a GFP-labeled Kbtbd13-transgenic zebrafish model, we discovered that KBTBD13 binds to actin — a major constituent of the thin filament — and that mutations in KBTBD13 cause structural changes impairing muscle-relaxation kinetics. We propose that this actin-based impaired relaxation is central to NEM6 pathology.
Authors
Josine M. de Winter, Joery P. Molenaar, Michaela Yuen, Robbert van der Pijl, Shengyi Shen, Stefan Conijn, Martijn van de Locht, Menne Willigenburg, Sylvia J.P. Bogaards, Esmee S.B. van Kleef, Saskia Lassche, Malin Persson, Dilson E. Rassier, Tamar E. Sztal, Avnika A. Ruparelia, Viola Oorschot, Georg Ramm, Thomas E. Hall, Zherui Xiong, Christopher N. Johnson, Frank Li, Balazs Kiss, Noelia Lozano-Vidal, Reinier A. Boon, Manuela Marabita, Leonardo Nogara, Bert Blaauw, Richard J. Rodenburg, Benno Küsters, Jonne Doorduin, Alan H. Beggs, Henk Granzier, Ken Campbell, Weikang Ma, Thomas Irving, Edoardo Malfatti, Norma B. Romero, Robert J. Bryson-Richardson, Baziel G.M. van Engelen, Nicol C. Voermans, Coen A.C. Ottenheijm
×Abstract
CD4+ T cell failure is a hallmark of chronic hepatitis C virus (HCV) infection. However, the mechanisms underlying the impairment and loss of virus-specific CD4+ T cells in persisting HCV infection remain unclear. Here we examined HCV-specific CD4+ T cells longitudinally during acute infection with different infection outcomes. We found that HCV-specific CD4+ T cells are characterized by expression of a narrower range of T cell inhibitory receptors compared with CD8+ T cells, with initially high expression levels of PD-1 and CTLA-4 that were associated with negative regulation of proliferation in all patients, irrespective of outcome. In addition, HCV-specific CD4+ T cells were phenotypically similar during early resolving and persistent infection and secreted similar levels of cytokines. However, upon viral control, CD4+ T cells quickly downregulated inhibitory receptors and differentiated into long-lived memory cells. In contrast, persisting viremia continued to drive T cell activation and PD-1 and CTLA-4 expression, and blocked T cell differentiation, until the cells quickly disappeared from the circulation. Our data support an important and physiological role for inhibitory receptor–mediated regulation of CD4+ T cells in early HCV infection, irrespective of outcome, with persistent HCV viremia leading to sustained upregulation of PD-1 and CTLA-4.
Authors
Diana Y. Chen, David Wolski, Jasneet Aneja, Lyndon Matsubara, Brandon Robilotti, Garrett Hauck, Paulo Sergio Fonseca de Sousa, Sonu Subudhi, Carlos Augusto Fernandes, Ruben C. Hoogeveen, Arthur Y. Kim, Lia Lewis-Ximenez, Georg M. Lauer
×Abstract
Efficacy of dendritic cell (DC) cancer vaccines is classically thought to depend on their antigen-presenting cell (APC) activity. Studies show, however, that DC vaccine priming of cytotoxic T lymphocytes (CTLs) requires the activity of endogenous DCs, suggesting that exogenous DCs stimulate antitumor immunity by transferring antigens (Ags) to endogenous DCs. Such Ag transfer functions are most commonly ascribed to monocytes, implying that undifferentiated monocytes would function equally well as a vaccine modality and need not be differentiated to DCs to be effective. Here, we used several murine cancer models to test the antitumor efficacy of undifferentiated monocytes loaded with protein or peptide Ag. Intravenously injected monocytes displayed antitumor activity superior to DC vaccines in several cancer models, including aggressive intracranial glioblastoma. Ag-loaded monocytes induced robust CTL responses via Ag transfer to splenic CD8+ DCs in a manner independent of monocyte APC activity. Ag transfer required cell-cell contact and the formation of connexin 43–containing gap junctions between monocytes and DCs. These findings demonstrate the existence of an efficient gap junction–mediated Ag transfer pathway between monocytes and CD8+ DCs and suggest that administration of tumor Ag–loaded undifferentiated monocytes may serve as a simple and efficacious immunotherapy for the treatment of human cancers.
Authors
Min-Nung Huang, Lowell T. Nicholson, Kristen A. Batich, Adam M. Swartz, David Kopin, Sebastian Wellford, Vijay K. Prabhakar, Karolina Woroniecka, Smita K. Nair, Peter E. Fecci, John H. Sampson, Michael D. Gunn
×Abstract
CD8+ T cell responses are necessary for immune control of simian immunodeficiency virus (SIV). However, the key parameters that dictate antiviral potency remain elusive, conceivably because most studies to date have been restricted to analyses of circulating CD8+ T cells. We conducted a detailed clonotypic, functional, and phenotypic survey of SIV-specific CD8+ T cells across multiple anatomical sites in chronically infected rhesus macaques with high (>10,000 copies/mL plasma) or low burdens of viral RNA (<10,000 copies/mL plasma). No significant differences in response magnitude were identified across anatomical compartments. Rhesus macaques with low viral loads (VLs) harbored higher frequencies of polyfunctional CXCR5+ SIV-specific CD8+ T cells in various lymphoid tissues and higher proportions of unique Gag-specific CD8+ T cell clonotypes in the mesenteric lymph nodes relative to rhesus macaques with high VLs. In addition, public Gag-specific CD8+ T cell clonotypes were more commonly shared across distinct anatomical sites than the corresponding private clonotypes, which tended to form tissue-specific repertoires, especially in the peripheral blood and the gastrointestinal tract. Collectively, these data suggest that functionality and tissue localization are important determinants of CD8+ T cell–mediated efficacy against SIV.
Authors
Carly E. Starke, Carol L. Vinton, Kristin Ladell, James E. McLaren, Alexandra M. Ortiz, Joseph C. Mudd, Jacob K. Flynn, Stephen H. Lai, Fan Wu, Vanessa M. Hirsch, Samuel Darko, Daniel C. Douek, David A. Price, Jason M. Brenchley
×Abstract
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever caused by a tick-borne banyangvirus and is associated with high fatality. Despite increasing incidence of SFTS and serious public health concerns in East Asia, the pathogenesis of lethal SFTS virus (SFTSV) infection in humans is not fully understood. Numbers of postmortem examinations to determine target cells of the viral infection have so far been limited. Here we showed that B cells differentiating into plasmablasts and macrophages in secondary lymphoid organs were targets for SFTSV at the end stage of lethal infection, and the majority of SFTSV-infected cells were B cell–lineage lymphocytes. In affected individuals, B cell–lineage lymphocytes with SFTSV infection were widely distributed in both lymphoid and nonlymphoid organs, and infiltration of these cells into the capillaries of the organs could be observed occasionally. Moreover, a human plasmablastic lymphoma cell line, PBL-1, was susceptible to SFTSV propagation and had a similar immunophenotype to that of target cells of SFTSV in fatal SFTS. PBL-1 can therefore provide a potential in vitro model for human SFTSV infection. These results extend our understanding of the pathogenesis of human lethal SFTSV infection and can facilitate the development of SFTSV countermeasures.
Authors
Tadaki Suzuki, Yuko Sato, Kaori Sano, Takeshi Arashiro, Harutaka Katano, Noriko Nakajima, Masayuki Shimojima, Michiyo Kataoka, Kenta Takahashi, Yuji Wada, Shigeru Morikawa, Shuetsu Fukushi, Tomoki Yoshikawa, Masayuki Saijo, Hideki Hasegawa
×Abstract
Multipass membrane proteins have a myriad of functions, including transduction of cell-cell signals, ion transport, and photoreception. Insertion of these proteins into the membrane depends on the endoplasmic reticulum (ER) membrane protein complex (EMC). Recently, birth defects have been observed in patients with variants in the gene encoding a member of this complex, EMC1. Patient phenotypes include congenital heart disease, craniofacial malformations, and neurodevelopmental disease. However, a molecular connection between EMC1 and these birth defects is lacking. Using Xenopus, we identified defects in neural crest cells (NCCs) upon emc1 depletion. We then used unbiased proteomics and discovered a critical role for emc1 in WNT signaling. Consistent with this, readouts of WNT signaling and Frizzled (Fzd) levels were reduced in emc1-depleted embryos, while NCC defects could be rescued with β-catenin. Interestingly, other transmembrane proteins were mislocalized upon emc1 depletion, providing insight into additional patient phenotypes. To translate our findings back to humans, we found that EMC1 was necessary for human NCC development in vitro. Finally, we tested patient variants in our Xenopus model and found the majority to be loss-of-function alleles. Our findings define molecular mechanisms whereby EMC1 dysfunction causes disease phenotypes through dysfunctional multipass membrane protein topogenesis.
Authors
Jonathan Marquez, June Criscione, Rebekah M. Charney, Maneeshi S. Prasad, Woong Y. Hwang, Emily K. Mis, Martín I. García-Castro, Mustafa K. Khokha
×Abstract
Interventions to prevent HIV-1 infection and alternative tools in HIV cure therapy remain pressing goals. Recently, numerous broadly neutralizing HIV-1 monoclonal antibodies (bNAbs) have been developed that possess the characteristics necessary for potential prophylactic or therapeutic approaches. However, formulation complexities, especially for multiantibody deliveries, long infusion times, and production issues could limit the use of these bNAbs when deployed, globally affecting their potential application. Here, we describe an approach utilizing synthetic DNA-encoded monoclonal antibodies (dmAbs) for direct in vivo production of prespecified neutralizing activity. We designed 16 different bNAbs as dmAb cassettes and studied their activity in small and large animals. Sera from animals administered dmAbs neutralized multiple HIV-1 isolates with activity similar to that of their parental recombinant mAbs. Delivery of multiple dmAbs to a single animal led to increased neutralization breadth. Two dmAbs, PGDM1400 and PGT121, were advanced into nonhuman primates for study. High peak-circulating levels (between 6 and 34 μg/ml) of these dmAbs were measured, and the sera of all animals displayed broad neutralizing activity. The dmAb approach provides an important local delivery platform for the in vivo generation of HIV-1 bNAbs and for other infectious disease antibodies.
Authors
Megan C. Wise, Ziyang Xu, Edgar Tello-Ruiz, Charles Beck, Aspen Trautz, Ami Patel, Sarah T.C. Elliott, Neethu Chokkalingam, Sophie Kim, Melissa G. Kerkau, Kar Muthumani, Jingjing Jiang, Paul D. Fisher, Stephany J. Ramos, Trevor R.F. Smith, Janess Mendoza, Kate E. Broderick, David C. Montefiori, Guido Ferrari, Daniel W. Kulp, Laurent M. Humeau, David B. Weiner
×Abstract
Pattern recognition receptors (PRRs) are crucial for responses to infections and tissue damage; however, their role in autoimmunity is less clear. Herein we demonstrate that 2 C-type lectin receptors (CLRs) Mcl and Mincle play an important role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Congenic rats expressing lower levels of Mcl and Mincle on myeloid cells exhibited a drastic reduction in EAE incidence. In vivo silencing of Mcl and Mincle or blockade of their endogenous ligand SAP130 revealed that these receptors’ expression in the central nervous system is crucial for T cell recruitment and reactivation into a pathogenic Th17/GM-CSF phenotype. Consistent with this, we uncovered MCL- and MINCLE-expressing cells in brain lesions of MS patients and we further found an upregulation of the MCL/MINCLE signaling pathway and an increased response following MCL/MINCLE stimulation in peripheral blood mononuclear cells from MS patients. Together, these data support a role for CLRs in autoimmunity and implicate the MCL/MINCLE pathway as a potential therapeutic target in MS.
Authors
Marie N’diaye, Susanna Brauner, Sevasti Flytzani, Lara Kular, Andreas Warnecke, Milena Z. Adzemovic, Eliane Piket, Jin-Hong Min, Will Edwards, Filia Mela, Hoi Ying Choi, Vera Magg, Tojo James, Magdalena Linden, Holger M. Reichardt, Michael R. Daws, Jack van Horssen, Ingrid Kockum, Robert A. Harris, Tomas Olsson, Andre O. Guerreiro-Cacais, Maja Jagodic
×Abstract
Oncogene-targeted and immune checkpoint therapies have revolutionized the clinical management of malignant melanoma and now offer hope to patients with advanced disease. Intimately connected to patients’ overall clinical risk is whether the initial primary melanoma lesion will metastasize and cause advanced disease, but underlying mechanisms are not entirely understood. A subset of melanomas display heightened peroxisome proliferator–activated receptor γ coactivator 1-α (PGC1α) expression that maintains cell survival cues by promoting mitochondrial function, but also suppresses metastatic spread. Here, we show that PGC1α expression in melanoma cells was silenced by chromatin modifications that involve promoter H3K27 trimethylation. Pharmacological EZH2 inhibition diminished H3K27me3 histone markers, increased PGC1α expression, and functionally suppressed invasion within PGC1α-silenced melanoma cells. Mechanistically, PGC1α silencing activated transcription factor 12 (TCF12), to increase expression of WNT5A, which in turn stabilized YAP protein levels to promote melanoma migration and metastasis. Accordingly, inhibition of components of this transcription-signaling axis, including TCF12, WNT5A, or YAP, blocked melanoma migration in vitro and metastasis in vivo. These results indicate that epigenetic control of melanoma metastasis involved altered expression of PGC1α and an association with the inherent metabolic state of the tumor.
Authors
Chi Luo, Eduardo Balsa, Elizabeth A. Perry, Jiaxin Liang, Clint D. Tavares, Francisca Vazquez, Hans R. Widlund, Pere Puigserver
×Abstract
Glucocorticoids (GCs) are a central component of therapy for patients with T cell acute lymphoblastic leukemia (T-ALL), and although resistance to GCs is a strong negative prognostic indicator in T-ALL, the mechanisms of GC resistance remain poorly understood. Using diagnostic samples from patients enrolled in the frontline Children’s Oncology Group (COG) T-ALL clinical trial AALL1231, we demonstrated that one-third of primary T-ALLs were resistant to GCs when cells were cultured in the presence of IL-7, a cytokine that is critical for normal T cell function and that plays a well-established role in leukemogenesis. We demonstrated that in these T-ALLs and in distinct populations of normal developing thymocytes, GCs paradoxically induced their own resistance by promoting upregulation of IL-7 receptor (IL-7R) expression. In the presence of IL-7, this augmented downstream signal transduction, resulting in increased STAT5 transcriptional output and upregulation of the prosurvival protein BCL-2. Taken together, we showed that IL-7 mediates an intrinsic and physiologic mechanism of GC resistance in normal thymocyte development that is retained during leukemogenesis in a subset of T-ALLs and is reversible with targeted inhibition of the IL-7R/JAK/STAT5/BCL-2 axis.
Authors
Lauren K. Meyer, Benjamin J. Huang, Cristina Delgado-Martin, Ritu P. Roy, Aaron Hechmer, Anica M. Wandler, Tiffaney L. Vincent, Paolo Fortina, Adam B. Olshen, Brent L. Wood, Terzah M. Horton, Kevin M. Shannon, David T. Teachey, Michelle L. Hermiston
×Abstract
Posttraumatic stress disorder (PTSD) can develop after exposure to severe psychological trauma, leaving patients with disabling anxiety, nightmares, and flashbacks. Current treatments are only partially effective, and development of better treatments is hampered by limited knowledge of molecular mechanisms underlying PTSD. We have discovered that the glucocorticoid receptor (GR) and FK506 binding protein 51 (FKBP51) form a protein complex that is elevated in PTSD patients compared with unaffected control subjects, subjects exposed to trauma without PTSD, and patients with major depressive disorder (MDD). The GR-FKBP51 complex is also elevated in fear-conditioned mice, an aversive learning paradigm that models some aspects of PTSD. Both PTSD patients and fear-conditioned mice had decreased GR phosphorylation, decreased nuclear GR, and lower expression of 14-3-3ε, a gene regulated by GR. We created a peptide that disrupts GR-FKBP51 binding and reverses behavioral and molecular changes induced by fear conditioning. This peptide reduces freezing time and increases GR phosphorylation, GR-FKBP52 binding, GR nuclear translocation, and 14-3-3ε expression in fear-conditioned mice. These experiments demonstrate a molecular mechanism contributing to PTSD and suggest that the GR-FKBP51 complex may be a diagnostic biomarker and a potential therapeutic target for preventing or treating PTSD.
Authors
Haiyin Li, Ping Su, Terence K.Y. Lai, Anlong Jiang, Jing Liu, Dongxu Zhai, Charlie T.G. Campbell, Frankie H.F. Lee, WeiDong Yong, Suvercha Pasricha, Shupeng Li, Albert H.C. Wong, Kerry J. Ressler, Fang Liu
×Abstract
The corneocyte lipid envelope, composed of covalently bound ceramides and fatty acids, is important to the integrity of the permeability barrier in the stratum corneum, and its absence is a prime structural defect in various skin diseases associated with defective skin barrier function. SDR9C7 encodes a short-chain dehydrogenase/reductase family 9C member 7 (SDR9C7) recently found mutated in ichthyosis. In a patient with SDR9C7 mutation and a mouse Sdr9c7-KO model, we show loss of covalent binding of epidermal ceramides to protein, a structural fault in the barrier. For reasons unresolved, protein binding requires lipoxygenase-catalyzed transformations of linoleic acid (18:2) esterified in ω-O-acylceramides. In Sdr9c7–/– epidermis, quantitative liquid chromatography–mass spectometry (LC-MS) assays revealed almost complete loss of a species of ω-O-acylceramide esterified with linoleate-9,10-trans-epoxy-11E-13-ketone; other acylceramides related to the lipoxygenase pathway were in higher abundance. Recombinant SDR9C7 catalyzed NAD+-dependent dehydrogenation of linoleate 9,10-trans-epoxy-11E-13-alcohol to the corresponding 13-ketone, while ichthyosis mutants were inactive. We propose, therefore, that the critical requirement for lipoxygenases and SDR9C7 is in producing acylceramide containing the 9,10-epoxy-11E-13-ketone, a reactive moiety known for its nonenzymatic coupling to protein. This suggests a mechanism for coupling of ceramide to protein and provides important insights into skin barrier formation and pathogenesis.
Authors
Takuya Takeichi, Tetsuya Hirabayashi, Yuki Miyasaka, Akane Kawamoto, Yusuke Okuno, Shijima Taguchi, Kana Tanahashi, Chiaki Murase, Hiroyuki Takama, Kosei Tanaka, William E. Boeglin, M. Wade Calcutt, Daisuke Watanabe, Michihiro Kono, Yoshinao Muro, Junko Ishikawa, Tamio Ohno, Alan R. Brash, Masashi Akiyama
×Abstract
Parkinson’s disease (PD) is a neurodegenerative disorder associated with loss of striatal dopamine, secondary to degeneration of midbrain dopamine (mDA) neurons in the substantia nigra, rendering cell transplantation a promising therapeutic strategy. To establish human induced pluripotent stem cell–based (hiPSC-based) autologous cell therapy, we report a platform of core techniques for the production of mDA progenitors as a safe and effective therapeutic product. First, by combining metabolism-regulating microRNAs with reprogramming factors, we developed a method to more efficiently generate clinical-grade iPSCs, as evidenced by genomic integrity and unbiased pluripotent potential. Second, we established a “spotting”-based in vitro differentiation methodology to generate functional and healthy mDA cells in a scalable manner. Third, we developed a chemical method that safely eliminates undifferentiated cells from the final product. Dopaminergic cells thus express high levels of characteristic mDA markers, produce and secrete dopamine, and exhibit electrophysiological features typical of mDA cells. Transplantation of these cells into rodent models of PD robustly restores motor function and reinnervates host brain, while showing no evidence of tumor formation or redistribution of the implanted cells. We propose that this platform is suitable for the successful implementation of human personalized autologous cell therapy for PD.
Authors
Bin Song, Young Cha, Sanghyeok Ko, Jeha Jeon, Nayeon Lee, Hyemyung Seo, Kyung-Joon Park, In-Hee Lee, Claudia Lopes, Melissa Feitosa, María José Luna, Jin Hyuk Jung, Jisun Kim, Dabin Hwang, Bruce M. Cohen, Martin H. Teicher, Pierre Leblanc, Bob S. Carter, Jeffrey H. Kordower, Vadim Y. Bolshakov, Sek Won Kong, Jeffrey S. Schweitzer, Kwang-Soo Kim
×Abstract
Risk for childhood asthma is conferred by alleles within the 17q21 locus affecting ORMDL sphingolipid biosynthesis regulator 3 (ORMDL3) expression. ORMDL3 inhibits sphingolipid de novo synthesis. Although the effects of 17q21 genotypes on sphingolipid synthesis in human asthma remain unclear, both decreased sphingolipid synthesis and ORMDL3 overexpression are linked to airway hyperreactivity. To characterize the relationship of genetic asthma susceptibility with sphingolipid synthesis, we analyzed asthma-associated 17q21 genotypes (rs7216389, rs8076131, rs4065275, rs12603332, and rs8067378) in both children with asthma and those without asthma, quantified plasma and whole-blood sphingolipids, and assessed sphingolipid de novo synthesis in peripheral blood cells by measuring the incorporation of stable isotope–labeled serine (substrate) into sphinganine and sphinganine-1-phosphate. Whole-blood dihydroceramides and ceramides were decreased in subjects with the 17q21 asthma–risk alleles rs7216389 and rs8076131. Children with nonallergic asthma had lower dihydroceramides, ceramides, and sphingomyelins than did controls. Children with allergic asthma had higher dihydroceramides, ceramides, and sphingomyelins compared with children with nonallergic asthma. Additionally, de novo sphingolipid synthesis was lower in children with asthma compared with controls. These findings connect genetic 17q21 variations that are associated with asthma risk and higher ORMDL3 expression to lower sphingolipid synthesis in humans. Altered sphingolipid synthesis may therefore be a critical factor in asthma pathogenesis and may guide the development of future therapeutics.
Authors
Jennie G. Ono, Benjamin I. Kim, Yize Zhao, Paul J. Christos, Yohannes Tesfaigzi, Tilla S. Worgall, Stefan Worgall
×Abstract
Successful infection by mucosal pathogens requires overcoming the mucus barrier. To better understand this key step, we performed a survey of the interactions between human respiratory mucus and the human pathogen Streptococcus pneumoniae. Pneumococcal adherence to adult human nasal fluid was seen only by isolates expressing pilus-1. Robust binding was independent of pilus-1 adhesive properties but required Fab-dependent recognition of RrgB, the pilus shaft protein, by naturally acquired secretory IgA (sIgA). Pilus-1 binding by specific sIgA led to bacterial agglutination, but adherence required interaction of agglutinated pneumococci and entrapment in mucus particles. To test the effect of these interactions in vivo, pneumococci were preincubated with human sIgA before intranasal challenge in a mouse model of colonization. sIgA treatment resulted in rapid immune exclusion of pilus-expressing pneumococci. Our findings predict that immune exclusion would select for nonpiliated isolates in individuals who acquired RrgB-specific sIgA from prior episodes of colonization with piliated strains. Accordingly, genomic data comparing isolates carried by mothers and their children showed that mothers are less likely to be colonized with pilus-expressing strains. Our study provides a specific example of immune exclusion involving naturally acquired antibody in the human host, a major factor driving pneumococcal adaptation.
Authors
Ulrike Binsker, John A. Lees, Alexandria J. Hammond, Jeffrey N. Weiser
×Abstract
Hereditary hemorrhagic telangiectasia (HHT), a genetic bleeding disorder leading to systemic arteriovenous malformations (AVMs), is caused by loss-of-function mutations in the ALK1/ENG/Smad1/5/8 pathway. Evidence suggests that HHT pathogenesis strongly relies on overactivated PI3K/Akt/mTOR and VEGFR2 pathways in endothelial cells (ECs). In the BMP9/10-immunoblocked (BMP9/10ib) neonatal mouse model of HHT, we report here that the mTOR inhibitor, sirolimus, and the receptor tyrosine kinase inhibitor, nintedanib, could synergistically fully block, but also reversed, retinal AVMs to avert retinal bleeding and anemia. Sirolimus plus nintedanib prevented vascular pathology in the oral mucosa, lungs, and liver of the BMP9/10ib mice, as well as significantly reduced gastrointestinal bleeding and anemia in inducible ALK1-deficient adult mice. Mechanistically, in vivo in BMP9/10ib mouse ECs, sirolimus and nintedanib blocked the overactivation of mTOR and VEGFR2, respectively. Furthermore, we found that sirolimus activated ALK2-mediated Smad1/5/8 signaling in primary ECs — including in HHT patient blood outgrowth ECs — and partially rescued Smad1/5/8 activity in vivo in BMP9/10ib mouse ECs. These data demonstrate that the combined correction of endothelial Smad1/5/8, mTOR, and VEGFR2 pathways opposes HHT pathogenesis. Repurposing of sirolimus plus nintedanib might provide therapeutic benefit in patients with HHT.
Authors
Santiago Ruiz, Haitian Zhao, Pallavi Chandakkar, Julien Papoin, Hyunwoo Choi, Aya Nomura-Kitabayashi, Radhika Patel, Matthew Gillen, Li Diao, Prodyot K. Chatterjee, Mingzhu He, Yousef Al-Abed, Ping Wang, Christine N. Metz, S. Paul Oh, Lionel Blanc, Fabien Campagne, Philippe Marambaud
×Abstract
Increased rates of locoregional recurrence are observed in patients with basal-like breast cancer (BC) despite the use of radiation therapy (RT); therefore, approaches that result in radiosensitization of basal-like BC are critically needed. Using patients’ tumor gene expression data from 4 independent data sets, we correlated gene expression with recurrence to find genes significantly correlated with early recurrence after RT. The highest-ranked gene, TTK, was most highly expressed in basal-like BC across multiple data sets. Inhibition of TTK by both genetic and pharmacologic methods enhanced radiosensitivity in multiple basal-like cell lines. Radiosensitivity was mediated, at least in part, through persistent DNA damage after treatment with TTK inhibition and RT. Inhibition of TTK impaired homologous recombination (HR) and repair efficiency, but not nonhomologous end-joining, and decreased the formation of Rad51 foci. Reintroduction of wild-type TTK rescued both radioresistance and HR repair efficiency after TTK knockdown; however, reintroduction of kinase-dead TTK did not. In vivo, TTK inhibition combined with RT led to a significant decrease in tumor growth in both heterotopic and orthotopic, including patient-derived xenograft, BC models. These data support the rationale for clinical development of TTK inhibition as a radiosensitizing strategy for patients with basal-like BC, and efforts toward this end are currently underway.
Authors
Benjamin C. Chandler, Leah Moubadder, Cassandra L. Ritter, Meilan Liu, Meleah Cameron, Kari Wilder-Romans, Amanda Zhang, Andrea M. Pesch, Anna R. Michmerhuizen, Nicole Hirsh, Marlie Androsiglio, Tanner Ward, Eric Olsen, Yashar S. Niknafs, Sofia Merajver, Dafydd G. Thomas, Powel H. Brown, Theodore S. Lawrence, Shyam Nyati, Lori J. Pierce, Arul Chinnaiyan, Corey Speers
×Abstract
Cancer immune evasion is achieved through multiple layers of immune tolerance mechanisms including immune editing, recruitment of tolerogenic immune cells, and secretion of immunosuppressive cytokines. Recent success with immune checkpoint inhibitors in cancer immunotherapy suggests a dysfunctional immune synapse as a pivotal tolerogenic mechanism. Tumor cells express immune synapse proteins to suppress the immune system, which is often modulated by epigenetic mechanisms. When the methylation status of key immune synapse genes was interrogated, we observed disproportionately hypermethylated costimulatory genes and hypomethylation of immune checkpoint genes, which were negatively associated with functional T cell recruitment to the tumor microenvironment. Therefore, the methylation status of immune synapse genes reflects tumor immunogenicity and correlates with survival.
Authors
Anders Berglund, Matthew Mills, Ryan M. Putney, Imène Hamaidi, James Mulé, Sungjune Kim
×Abstract
The protein-protein interaction between menin and mixed lineage leukemia 1 (MLL1) plays a critical role in acute leukemias with translocations of the MLL1 gene or with mutations in the nucleophosmin 1 (NPM1) gene. As a step toward clinical translation of menin-MLL1 inhibitors, we report development of MI-3454, a highly potent and orally bioavailable inhibitor of the menin-MLL1 interaction. MI-3454 profoundly inhibited proliferation and induced differentiation in acute leukemia cells and primary patient samples with MLL1 translocations or NPM1 mutations. When applied as a single agent, MI-3454 induced complete remission or regression of leukemia in mouse models of MLL1-rearranged or NPM1-mutated leukemia, including patient-derived xenograft models, through downregulation of key genes involved in leukemogenesis. We also identified MEIS1 as a potential pharmacodynamic biomarker of treatment response with MI-3454 in leukemia, and demonstrated that this compound is well tolerated and did not impair normal hematopoiesis in mice. Overall, this study demonstrates, for the first time to our knowledge, profound activity of the menin-MLL1 inhibitor as a single agent in clinically relevant PDX models of leukemia. These data provide a strong rationale for clinical translation of MI-3454 or its analogs for leukemia patients with MLL1 rearrangements or NPM1 mutations.
Authors
Szymon Klossowski, Hongzhi Miao, Katarzyna Kempinska, Tao Wu, Trupta Purohit, EunGi Kim, Brian M. Linhares, Dong Chen, Gloria Jih, Eric Perkey, Huang Huang, Miao He, Bo Wen, Yi Wang, Ke Yu, Stanley Chun-Wei Lee, Gwenn Danet-Desnoyers, Winifred Trotman, Malathi Kandarpa, Anitria Cotton, Omar Abdel-Wahab, Hongwei Lei, Yali Dou, Monica Guzman, Luke Peterson, Tanja Gruber, Sarah Choi, Duxin Sun, Pingda Ren, Lian-Sheng Li, Yi Liu, Francis Burrows, Ivan Maillard, Tomasz Cierpicki, Jolanta Grembecka
×Abstract
BACKGROUND Chronic hepatitis C virus (HCV) infection is characterized by a severe impairment of HCV-specific CD4+ T cell help that is driven by chronic antigen stimulation. We aimed to study the fate of HCV-specific CD4+ T cells after virus elimination.METHODS HCV-specific CD4+ T cell responses were longitudinally analyzed using MHC class II tetramer technology, multicolor flow cytometry, and RNA sequencing in a cohort of patients chronically infected with HCV undergoing therapy with direct-acting antivirals. In addition, HCV-specific neutralizing antibodies and CXCL13 levels were analyzed.RESULTS We observed that the frequency of HCV-specific CD4+ T cells increased within 2 weeks after initiating direct-acting antiviral therapy. Multicolor flow cytometry revealed a downregulation of exhaustion and activation markers and an upregulation of memory-associated markers. Although cells with a Th1 phenotype were the predominant subset at baseline, cells with phenotypic and transcriptional characteristics of follicular T helper cells increasingly shaped the circulating HCV-specific CD4+ T cell repertoire, suggesting antigen-independent survival of this subset. These changes were accompanied by a decline of HCV-specific neutralizing antibodies and the germinal center activity.CONCLUSION We identified a population of HCV-specific CD4+ T cells with a follicular T helper cell signature that is maintained after therapy-induced elimination of persistent infection and may constitute an important target population for vaccination efforts to prevent reinfection and immunotherapeutic approaches for persistent viral infections.FUNDING Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), the National Institute of Allergy and Infectious Diseases (NIAID), the European Union, the Berta-Ottenstein-Programme for Advanced Clinician Scientists, and the ANRS.
Authors
Maike Smits, Katharina Zoldan, Naveed Ishaque, Zuguang Gu, Katharina Jechow, Dominik Wieland, Christian Conrad, Roland Eils, Catherine Fauvelle, Thomas F. Baumert, Florian Emmerich, Bertram Bengsch, Christoph Neumann-Haefelin, Maike Hofmann, Robert Thimme, Tobias Boettler
×Abstract
Increases in the number of cell therapies in the preclinical and clinical phases have prompted the need for reliable and noninvasive assays to validate transplant function in clinical biomanufacturing. We developed a robust characterization methodology composed of quantitative bright-field absorbance microscopy (QBAM) and deep neural networks (DNNs) to noninvasively predict tissue function and cellular donor identity. The methodology was validated using clinical-grade induced pluripotent stem cell–derived retinal pigment epithelial cells (iPSC-RPE). QBAM images of iPSC-RPE were used to train DNNs that predicted iPSC-RPE monolayer transepithelial resistance, predicted polarized vascular endothelial growth factor (VEGF) secretion, and matched iPSC-RPE monolayers to the stem cell donors. DNN predictions were supplemented with traditional machine-learning algorithms that identified shape and texture features of single cells that were used to predict tissue function and iPSC donor identity. These results demonstrate noninvasive cell therapy characterization can be achieved with QBAM and machine learning.
Authors
Nicholas J. Schaub, Nathan A. Hotaling, Petre Manescu, Sarala Padi, Qin Wan, Ruchi Sharma, Aman George, Joe Chalfoun, Mylene Simon, Mohamed Ouladi, Carl G. Simon Jr., Peter Bajcsy, Kapil Bharti
×Abstract
Leptomeningeal anastomoses or pial collateral vessels play a critical role in cerebral blood flow (CBF) restoration following ischemic stroke. The magnitude of this adaptive response is postulated to be controlled by the endothelium, although the underlying molecular mechanisms remain under investigation. Here we demonstrated that endothelial genetic deletion, using EphA4fl/fl/Tie2-Cre and EphA4fl/fl/VeCahderin-CreERT2 mice and vessel painting strategies, implicated EphA4 receptor tyrosine kinase as a major suppressor of pial collateral remodeling, CBF, and functional recovery following permanent middle cerebral artery occlusion. Pial collateral remodeling is limited by the crosstalk between EphA4-Tie2 signaling in vascular endothelial cells, which is mediated through p-Akt regulation. Furthermore, peptide inhibition of EphA4 resulted in acceleration of the pial arteriogenic response. Our findings demonstrate that EphA4 is a negative regulator of Tie2 receptor signaling, which limits pial collateral arteriogenesis following cerebrovascular occlusion. Therapeutic targeting of EphA4 and/or Tie2 represents an attractive new strategy for improving collateral function, neural tissue health, and functional recovery following ischemic stroke.
Authors
Benjamin Okyere, William A. Mills III, Xia Wang, Michael Chen, Jiang Chen, Amanda Hazy, Yun Qian, John B. Matson, Michelle H. Theus
×Abstract
Antigen receptor–dependent (AgR-dependent) stimulation of the NF-κB transcription factor in lymphocytes is a required event during adaptive immune response, but dysregulated activation of this signaling pathway can lead to lymphoma. AgR stimulation promotes assembly of the CARMA1-BCL10-MALT1 complex, wherein MALT1 acts as (a) a scaffold to recruit components of the canonical NF-κB machinery and (b) a protease to cleave and inactivate specific substrates, including negative regulators of NF-κB. In multiple lymphoma subtypes, malignant B cells hijack AgR signaling pathways to promote their own growth and survival, and inhibiting MALT1 reduces the viability and growth of these tumors. As such, MALT1 has emerged as a potential pharmaceutical target. Here, we identified G protein–coupled receptor kinase 2 (GRK2) as a new MALT1-interacting protein. We demonstrated that GRK2 binds the death domain of MALT1 and inhibits MALT1 scaffolding and proteolytic activities. We found that lower GRK2 levels in activated B cell–type diffuse large B cell lymphoma (ABC-DLBCL) are associated with reduced survival, and that GRK2 knockdown enhances ABC-DLBCL tumor growth in vitro and in vivo. Together, our findings suggest that GRK2 can function as a tumor suppressor by inhibiting MALT1 and provide a roadmap for developing new strategies to inhibit MALT1-dependent lymphomagenesis.
Authors
Jing Cheng, Linda R. Klei, Nathaniel E. Hubel, Ming Zhang, Rebekka Schairer, Lisa M. Maurer, Hanna B. Klei, Heejae Kang, Vincent J. Concel, Phillip C. Delekta, Eric V. Dang, Michelle A. Mintz, Mathijs Baens, Jason G. Cyster, Narayanan Parameswaran, Margot Thome, Peter C. Lucas, Linda M. McAllister-Lucas
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ISSN: 0021-9738 (print), 1558-8238 (online)