45 total articles
Adult-onset autosomal-dominant leukodystrophy (ADLD) is a rare neurological disorder characterized by a progressive loss of myelin in the central nervous system. In this month’s
Hepcidin is a key hormone that is involved in the control of iron homeostasis in the body. Physiologically, hepcidin is controlled by iron stores, inflammation, hypoxia, and erythropoiesis. The regulation of hepcidin expression by iron is a complex process that requires the coordination of multiple proteins, including hemojuvelin, bone morphogenetic protein 6 (BMP6), hereditary hemochromatosis protein, transferrin receptor 2, matriptase-2, neogenin, BMP receptors, and transferrin. Misregulation of hepcidin is found in many disease states, such as the anemia of chronic disease, iron refractory iron deficiency anemia, cancer, hereditary hemochromatosis, and ineffective erythropoiesis, such as β-thalassemia. Thus, the regulation of hepcidin is the subject of interest for the amelioration of the detrimental effects of either iron deficiency or overload.
Ningning Zhao, An-Sheng Zhang, Caroline A. Enns
The discovery of the adipocyte hormone leptin and the demonstration that severe obesity in
Michael W. Schwartz, Denis G. Baskin
A 40-year-old NIH male scientist camped and fished in a remote lake in Alaska. On his return, he developed diarrhea, cramps, and loose stools without blood or mucus in the absence of fever and was diagnosed with giardiasis. A 3-year-old female living in the Florida Keys complained of intermittent stomachaches over a 2-month period. Her stools were variably loose. The patient was diagnosed with giardiasis, which led to examination of her mother, father, and brother, who were mildly symptomatic; all 3 were subsequently diagnosed with giardiasis. The child’s only exposure was from swimming in a local community pool. A 40-year-old male from Mexico, who resided in Virginia and worked as a cook in a fast food restaurant, was diagnosed with giardiasis. He denied any symptoms and was not allowed to prepare food. Treatment with metronidazole, nitazoxanide, and albendazole failed to eradicate the infection. He was successfully treated with the combination of paromomycin and metronidazole.
Theodore E. Nash
A 5-year-old girl has come to you a week after completing a course of antibiotics for a febrile urinary tract infection (UTI). She now seems well and energetic. A urinalysis is now clear without traces of inflammation, including an absence of protein, blood, leukocyte esterase, and nitrites. Her urine is submitted for a test of cure and comes back positive, with over 100,000 colonies per milliliter of
Patrick C. Seed
The absence of reliable quantitative laboratory tests for measurements of microRNAs and other classes of small noncoding RNAs in archived, formalin-fixed, paraffin-embedded human samples with sufficient specificity and sensitivity has significantly limited the development of clinically relevant noncoding RNA–based diagnostic and therapeutic applications. A report by Renwick et al. in this issue of the
Gennadi V. Glinsky
The highly prevalent protozoan
Herbert L. DuPont
Failing immunity has been acknowledged for its contribution to cancer development and progression. Recent clinical findings have provided payoffs for significant preclinical evaluation and refinement over the last 20 years, but many questions remain to be answered. In this issue of the
Cristina Ghirelli, Thorsten Hagemann
The study in this issue of the
V. Michael Holers
During transplant rejection, migrating T cells infiltrate the grafted organ, but the signals that direct this migration are incompletely understood. In this issue of the
Terry B. Strom
There is a ying/yang to most biological therapies, and the balance of efficacy versus toxicity is delicate and sometimes difficult to achieve in favor of the patients. When the therapeutic window is wide, these therapies can be used in the majority of patients, but when the therapeutic window is narrow, the decision to proceed must be carefully balanced with a thoughtful risk-benefit analysis. In this issue of the
Translating new findings in the laboratory into therapies for patients is a slow and expensive process. The development of therapies for neurodegenerative diseases is further complicated by the difficulty in determining whether the drug truly retards the slow degenerative process or provides only symptomatic benefit. In this issue, Aviles-Olmos et al. describe a first in Parkinson’s disease (PD) patient study using a drug previously approved for diabetes treatment. In addition to suggesting that the drug may indeed be disease modifying in PD, their innovative approach suggests there may be more rapid and inexpensive avenues for testing novel therapies in PD.
Roger A. Barker, Mark Stacy, Patrik Brundin
The normal flora furnishes the host with ecological barriers that prevent pathogen attack while maintaining tissue homeostasis. Urinary tract infections (UTIs) constitute a highly relevant model of microbial adaptation in which some patients infected with
Nataliya Lutay, Ines Ambite, Jenny Grönberg Hernandez, Gustav Rydström, Bryndís Ragnarsdóttir, Manoj Puthia, Aftab Nadeem, Jingyao Zhang, Petter Storm, Ulrich Dobrindt, Björn Wullt, Catharina Svanborg
When regenerative processes cannot keep pace with cell death, functional epithelia are replaced by scar. Scarring is characterized by both excessive accumulation of fibrous matrix and persistent outgrowth of cell types that accumulate transiently during successful wound healing, including myofibroblasts (MFs) and progenitors. This suggests that signaling that normally directs these cells to repair injured epithelia is deregulated. To evaluate this possibility, we examined liver repair during different types of liver injury after Smoothened (SMO), an obligate intermediate in the Hedgehog (Hh) signaling pathway, was conditionally deleted in cells expressing the MF-associated gene, α
Gregory A. Michelotti, Guanhua Xie, Marzena Swiderska, Steve S. Choi, Gamze Karaca, Leandi Krüger, Richard Premont, Liu Yang, Wing-Kin Syn, Daniel Metzger, Anna Mae Diehl
We examined the role of microRNAs (miRNAs) in targeting the stromal-derived factor 1α/CXCR4 (SDF-1α/CXCR4) axis to overcome chemoresistance of AML cells. Microarray analysis of OCI-AML3 cells revealed that the miRNA let-7a was downregulated by SDF-1α–mediated CXCR4 activation and increased by CXCR4 inhibition. Overexpression of let-7a in AML cell lines was associated with decreased c-Myc and BCL-XL protein expression and enhanced chemosensitivity, both in vitro and in vivo. We identified the transcription factor Yin Yang 1 (YY1) as a link between SDF-1α/CXCR4 signaling and let-7a, as YY1 was upregulated by SDF-1α and downregulated by treatment with a CXCR4 antagonist. ChIP assay confirmed the binding of YY1 to unprocessed let-7a DNA fragments, and treatment with
Ye Chen, Rodrigo Jacamo, Marina Konopleva, Ramiro Garzon, Carlo Croce, Michael Andreeff
The remodeling of maternal uterine spiral arteries (SAs) is an essential process for ensuring low-resistance, high-capacitance blood flow to the growing fetus. Failure of SAs to remodel is causally associated with preeclampsia, a common and life-threatening complication of pregnancy that is harmful to both mother and fetus. Here, using both loss-of-function and gain-of-function genetic mouse models, we show that expression of the pregnancy-related peptide adrenomedullin (AM) by fetal trophoblast cells is necessary and sufficient to promote appropriate recruitment and activation of maternal uterine NK (uNK) cells to the placenta and ultimately facilitate remodeling of maternal SAs. Placentas that lacked either AM or its receptor exhibited reduced fetal vessel branching in the labyrinth, failed SA remodeling and reendothelialization, and markedly reduced numbers of maternal uNK cells. In contrast, overexpression of AM caused a reversal of these phenotypes with a concomitant increase in uNK cell content in vivo. Moreover, AM dose-dependently stimulated the secretion of numerous chemokines, cytokines, and MMPs from uNK cells, which in turn induced VSMC apoptosis. These data identify an essential function for fetal-derived factors in the maternal vascular adaptation to pregnancy and underscore the importance of exploring AM as a biomarker and therapeutic agent for preeclampsia.
Manyu Li, Nicole M.J. Schwerbrock, Patricia M. Lenhart, Kimberly L. Fritz-Six, Mahita Kadmiel, Kathleen S. Christine, Daniel M. Kraus, Scott T. Espenschied, Helen H. Willcockson, Christopher P. Mack, Kathleen M. Caron
The osteoblast-derived hormone osteocalcin promotes testosterone biosynthesis in the mouse testis by binding to GPRC6A in Leydig cells. Interestingly,
Franck Oury, Mathieu Ferron, Wang Huizhen, Cyrille Confavreux, Lin Xu, Julie Lacombe, Prashanth Srinivas, Alexandre Chamouni, Francesca Lugani, Herve Lejeune, T. Rajendra Kumar, Ingrid Plotton, Gerard Karsenty
C3 glomerulopathies (C3G) are a group of severe renal diseases with distinct patterns of glomerular inflammation and C3 deposition caused by complement dysregulation. Here we report the identification of a familial C3G-associated genomic mutation in the gene complement factor H–related 1 (
Agustín Tortajada, Hugo Yébenes, Cynthia Abarrategui-Garrido, Jaouad Anter, Jesús M. García-Fernández, Rubén Martínez-Barricarte, María Alba-Domínguez, Talat H. Malik, Rafael Bedoya, Rocío Cabrera Pérez, Margarita López Trascasa, Matthew C. Pickering, Claire L. Harris, Pilar Sánchez-Corral, Oscar Llorca, Santiago Rodríguez de Córdoba
Activation of TLR9 by direct injection of unmethylated CpG nucleotides into a tumor can induce a therapeutic immune response; however, Tregs eventually inhibit the antitumor immune response and thereby limit the power of cancer immunotherapies. In tumor-bearing mice, we found that Tregs within the tumor preferentially express the cell surface markers CTLA-4 and OX40. We show that intratumoral coinjection of anti–CTLA-4 and anti-OX40 together with CpG depleted tumor-infiltrating Tregs. This in situ immunomodulation, which was performed with low doses of antibodies in a single tumor, generated a systemic antitumor immune response that eradicated disseminated disease in mice. Further, this treatment modality was effective against established CNS lymphoma with leptomeningeal metastases, sites that are usually considered to be tumor cell sanctuaries in the context of conventional systemic therapy. These results demonstrate that antitumor immune effectors elicited by local immunomodulation can eradicate tumor cells at distant sites. We propose that, rather than using mAbs to target cancer cells systemically, mAbs could be used to target the tumor infiltrative immune cells locally, thereby eliciting a systemic immune response.
Aurélien Marabelle, Holbrook Kohrt, Idit Sagiv-Barfi, Bahareh Ajami, Robert C. Axtell, Gang Zhou, Ranjani Rajapaksa, Michael R. Green, James Torchia, Joshua Brody, Richard Luong, Michael D. Rosenblum, Lawrence Steinman, Hyam I. Levitsky, Victor Tse, Ronald Levy
B cell–dependent immunity to rotavirus, an important intestinal pathogen, plays a significant role in viral clearance and protects against reinfection. Human in vitro and murine in vivo models of rotavirus infection were used to delineate the role of primary plasmacytoid DCs (pDCs) in initiating B cell responses. Human pDCs were necessary and sufficient for B cell activation induced by rotavirus. Type I IFN recognition by B cells was essential for rotavirus-mediated B cell activation in vitro and murine pDCs and IFN-α/β–mediated B cell activation after in vivo intestinal rotavirus infection. Furthermore, rotavirus-specific serum and mucosal antibody responses were defective in mice lacking functional pDCs at the time of infection. These data demonstrate that optimal B cell activation and virus-specific antibody secretion following mucosal infection were a direct result of pDC-derived type I IFN. Importantly, viral shedding significantly increased in pDC-deficient mice, suggesting that pDC-dependent antibody production influences viral clearance. Thus, mucosal pDCs critically influence the course of rotavirus infection through rotavirus recognition and subsequent IFN production and display powerful adjuvant properties to initiate and enhance humoral immunity.
Emily M. Deal, Katharina Lahl, Carlos F. Narváez, Eugene C. Butcher, Harry B. Greenberg
Glioblastomas (GBMs) are very aggressive tumors that are resistant to conventional chemo- and radiotherapy. New molecular therapeutic strategies are required to effectively eliminate the subpopulation of GBM tumor–initiating cells that are responsible for relapse. Since EGFR is altered in 50% of GBMs, it represents one of the most promising targets; however, EGFR kinase inhibitors have produced poor results in clinical assays, with no clear explanation for the observed resistance. We uncovered a fundamental role for the dual-specificity tyrosine phosphorylation–regulated kinase, DYRK1A, in regulating EGFR in GBMs. We found that DYRK1A was highly expressed in these tumors and that its expression was correlated with that of EGFR. Moreover, DYRK1A inhibition promoted EGFR degradation in primary GBM cell lines and neural progenitor cells, sharply reducing the self-renewal capacity of normal and tumorigenic cells. Most importantly, our data suggest that a subset of GBMs depends on high surface EGFR levels, as DYRK1A inhibition compromised their survival and produced a profound decrease in tumor burden. We propose that the recovery of EGFR stability is a key oncogenic event in a large proportion of gliomas and that pharmacological inhibition of DYRK1A could represent a promising therapeutic intervention for EGFR-dependent GBMs.
Natividad Pozo, Cristina Zahonero, Paloma Fernández, Jose M. Liñares, Angel Ayuso, Masatoshi Hagiwara, Angel Pérez, Jose R. Ricoy, Aurelio Hernández-Laín, Juan M. Sepúlveda, Pilar Sánchez-Gómez
High-risk types of human papilloma virus (HPV) are increasingly associated with oropharyngeal squamous cell carcinoma (OPSCC). Strikingly, patients with HPV-positive OPSCC are highly curable with ionizing radiation and have better survival compared with HPV-negative patients, but the underlying molecular mechanisms remain poorly understood. We applied an array-based approach to monitor global changes in CpG island hypermethylation between HPV-negative and HPV-positive OPSCCs and identified a specific pattern of differentially methylated regions that critically depends on the presence of viral transcripts. HPV-related alterations were confirmed for the majority of candidate gene promoters by mass spectrometric, quantitative methylation analysis. There was a significant inverse correlation between promoter hypermethylation of
Efterpi Kostareli, Dana Holzinger, Olga Bogatyrova, Thomas Hielscher, Gunnar Wichmann, Michaela Keck, Bernd Lahrmann, Niels Grabe, Christa Flechtenmacher, Christopher R. Schmidt, Tanguy Seiwert, Gerhard Dyckhoff, Andreas Dietz, Daniela Höfler, Michael Pawlita, Axel Benner, Franz X. Bosch, Peter Plinkert, Christoph Plass, Dieter Weichenhan, Jochen Hess
Small intestine neuroendocrine tumors (SI-NETs) are the most common malignancy of the small bowel. Several clinical trials target PI3K/Akt/mTOR signaling; however, it is unknown whether these or other genes are genetically altered in these tumors. To address the underlying genetics, we analyzed 48 SI-NETs by massively parallel exome sequencing. We detected an average of 0.1 somatic single nucleotide variants (SNVs) per 106 nucleotides (range, 0–0.59), mostly transitions (C>T and A>G), which suggests that SI-NETs are stable cancers. 197 protein-altering somatic SNVs affected a preponderance of cancer genes, including
Michaela S. Banck, Rahul Kanwar, Amit A. Kulkarni, Ganesh K. Boora, Franziska Metge, Benjamin R. Kipp, Lizhi Zhang, Erik C. Thorland, Kay T. Minn, Ramesh Tentu, Bruce W. Eckloff, Eric D. Wieben, Yanhong Wu, Julie M. Cunningham, David M. Nagorney, Judith A. Gilbert, Matthew M. Ames, Andreas S. Beutler
NF-κB is constitutively activated in many cancer types and is a potential key mediator of tumor-associated inflammation, tumor growth, and metastasis. We investigated the role of cancer cell NF-κB activity in T cell–mediated antitumor responses. In tumors rendered immunogenic by model antigen expression or following administration of antitumor vaccines, we found that high NF-κB activity leads to tumor rejection and/or growth suppression in mice. Using a global RNA expression microarray, we demonstrated that NF-κB enhanced expression of several T cell chemokines, including
Emily L. Hopewell, Weipeng Zhao, William J. Fulp, Crystina C. Bronk, Alexis S. Lopez, Michael Massengill, Scott Antonia, Esteban Celis, Eric B. Haura, Steven A. Enkemann, Dung-Tsa Chen, Amer A. Beg
A disintegrin and metalloproteinase 10 (ADAM10), a disintegrin and metalloproteinase that resides in the postsynaptic densities (PSDs) of excitatory synapses, has previously been shown to limit β-amyloid peptide (Aβ) formation in Alzheimer’s disease (AD). ADAM10 also plays a critical role in regulating functional membrane proteins at the synapse. Using human hippocampal homogenates, we found that ADAM10 removal from the plasma membrane was mediated by clathrin-dependent endocytosis. Additionally, we identified the clathrin adaptor AP2 as an interacting partner of a previously uncharacterized atypical binding motif in the ADAM10 C-terminal domain. This domain was required for ADAM10 endocytosis and modulation of its plasma membrane levels. We found that the ADAM10/AP2 association was increased in the hippocampi of AD patients compared with healthy controls. Long-term potentiation (LTP) in hippocampal neuronal cultures induced ADAM10 endocytosis through AP2 association and decreased surface ADAM10 levels and activity. Conversely, long-term depression (LTD) promoted ADAM10 synaptic membrane insertion and stimulated its activity. ADAM10 interaction with the synapse-associated protein-97 (SAP97) was necessary for LTD-induced ADAM10 trafficking and required for LTD maintenance and LTD-induced changes in spine morphogenesis. These data identify and characterize a mechanism controlling ADAM10 localization and activity at excitatory synapses that is relevant to AD pathogenesis.
Elena Marcello, Claudia Saraceno, Stefano Musardo, Hugo Vara, Alerie Guzman de la Fuente, Silvia Pelucchi, Daniele Di Marino, Barbara Borroni, Anna Tramontano, Isabel Pérez-Otaño, Alessandro Padovani, Maurizio Giustetto, Fabrizio Gardoni, Monica Di Luca
Abnormalities in cell-cell communication and growth factor signaling pathways can
lead to defects in maternal-fetal interactions during pregnancy, including
immunologic rejection of the fetal/placental unit. In this study, we discovered that
bone morphogenetic protein receptor type 2 (BMPR2) is essential for postimplantation
physiology and fertility. Despite normal implantation and early placental/fetal
development, deletion of
Takashi Nagashima, Qinglei Li, Caterina Clementi, John P. Lydon, Francesco J. DeMayo, Martin M. Matzuk
The PI3K signaling pathway regulates diverse cellular processes, including proliferation, survival, and metabolism, and is aberrantly activated in human cancer. As such, numerous compounds targeting the PI3K pathway are currently being clinically evaluated for the treatment of cancer, and several have shown some early indications of efficacy in breast cancer. However, resistance against these agents, both de novo and acquired, may ultimately limit the efficacy of these compounds. Here, we have taken a systematic functional approach to uncovering potential mechanisms of resistance to PI3K inhibitors and have identified several genes whose expression promotes survival under conditions of PI3K/mammalian target of rapamycin (PI3K/mTOR) blockade, including the ribosomal S6 kinases
Violeta Serra, Pieter J.A. Eichhorn, Celina García-García, Yasir H. Ibrahim, Ludmila Prudkin, Gertrudis Sánchez, Olga Rodríguez, Pilar Antón, Josep-Lluís Parra, Sara Marlow, Maurizio Scaltriti, José Pérez-Garcia, Aleix Prat, Joaquín Arribas, William C. Hahn, So Young Kim, José Baselga
The mechanisms involved in the coordinate regulation of the metabolic and structural programs controlling muscle fitness and endurance are unknown. Recently, the nuclear receptor PPARβ/δ was shown to activate muscle endurance programs in transgenic mice. In contrast, muscle-specific transgenic overexpression of the related nuclear receptor, PPARα, results in reduced capacity for endurance exercise. We took advantage of the divergent actions of PPARβ/δ and PPARα to explore the downstream regulatory circuitry that orchestrates the programs linking muscle fiber type with energy metabolism. Our results indicate that, in addition to the well-established role in transcriptional control of muscle metabolic genes, PPARβ/δ and PPARα participate in programs that exert opposing actions upon the type I fiber program through a distinct muscle microRNA (miRNA) network, dependent on the actions of another nuclear receptor, estrogen-related receptor γ (ERRγ). Gain-of-function and loss-of-function strategies in mice, together with assessment of muscle biopsies from humans, demonstrated that type I muscle fiber proportion is increased via the stimulatory actions of ERRγ on the expression of miR-499 and miR-208b. This nuclear receptor/miRNA regulatory circuit shows promise for the identification of therapeutic targets aimed at maintaining muscle fitness in a variety of chronic disease states, such as obesity, skeletal myopathies, and heart failure.
Zhenji Gan, John Rumsey, Bethany C. Hazen, Ling Lai, Teresa C. Leone, Rick B. Vega, Hui Xie, Kevin E. Conley, Johan Auwerx, Steven R. Smith, Eric N. Olson, Anastasia Kralli, Daniel P. Kelly
JAK2 activity is tightly controlled through a self-inhibitory effect via its JAK homology domain 2 (JH2), which restricts the strength and duration of JAK2/STAT3 signaling under physiological conditions. Although multiple mutations within
Xiuting Chen, Zhe Ying, Xi Lin, Huanxin Lin, Jueheng Wu, Mengfeng Li, Libing Song
TNF has remarkable antitumor activities; however, therapeutic applications have not been possible because of the systemic and lethal proinflammatory effects induced by TNF. Both the antitumor and inflammatory effects of TNF are mediated by the TNF receptor p55 (p55TNFR) (encoded by the
Filip Van Hauwermeiren, Marietta Armaka, Niki Karagianni, Ksanthi Kranidioti, Roosmarijn E. Vandenbroucke, Sonja Loges, Maarten Van Roy, Jan Staelens, Leen Puimège, Ajay Palagani, Wim Vanden Berghe, Panayiotis Victoratos, Peter Carmeliet, Claude Libert, George Kollias
The inhibitory receptor programmed cell death 1 (PD-1) plays a major role in functional exhaustion of T cells during chronic infections and cancer, and recent clinical data suggest that blockade of the PD-1 pathway is an effective immunotherapy in treating certain cancers. Thus, it is important to define combinatorial approaches that increase the efficacy of PD-1 blockade. To address this issue, we examined the effect of IL-2 and PD-1 ligand 1 (PD-L1) blockade in the mouse model of chronic lymphocytic choriomeningitis virus (LCMV) infection. We found that low-dose IL-2 administration alone enhanced CD8+ T cell responses in chronically infected mice. IL-2 treatment also decreased inhibitory receptor levels on virus-specific CD8+ T cells and increased expression of CD127 and CD44, resulting in a phenotype resembling that of memory T cells. Surprisingly, IL-2 therapy had only a minimal effect on reducing viral load. However, combining IL-2 treatment with blockade of the PD-1 inhibitory pathway had striking synergistic effects in enhancing virus-specific CD8+ T cell responses and decreasing viral load. Interestingly, this reduction in viral load occurred despite increased numbers of Tregs. These results suggest that combined IL-2 therapy and PD-L1 blockade merits consideration as a regimen for treating human chronic infections and cancer.
Erin E. West, Hyun-Tak Jin, Ata-Ur Rasheed, Pablo Penaloza-MacMaster, Sang-Jun Ha, Wendy G. Tan, Ben Youngblood, Gordon J. Freeman, Kendall A. Smith, Rafi Ahmed
Primary effusion lymphoma (PEL) is a rare form of aggressive B cell lymphoma caused by Kaposi’s sarcoma-associated herpesvirus (KSHV). Current chemotherapy approaches result in dismal outcomes, and there is an urgent need for new PEL therapies. Previously, we established, in a direct xenograft model of PEL-bearing immune-compromised mice, that treatment with the proteasome inhibitor, bortezomib (Btz), increased survival relative to that after treatment with doxorubicin. Herein, we demonstrate that the combination of Btz with the histone deacetylase (HDAC) inhibitor suberoylanilidehydroxamic acid (SAHA, also known as vorinostat) potently reactivates KSHV lytic replication and induces PEL cell death, resulting in significantly prolonged survival of PEL-bearing mice. Importantly, Btz blocked KSHV late lytic gene expression, terminally inhibiting the full lytic cascade and production of infectious virus in vivo. Btz treatment led to caspase activation and induced DNA damage, as evidenced by the accumulation of phosphorylated γH2AX and p53. The addition of SAHA to Btz treatment was synergistic, as SAHA induced early acetylation of p53 and reduced interaction with its negative regulator MDM2, augmenting the effects of Btz. The eradication of KSHV-infected PEL cells without increased viremia in mice provides a strong rationale for using the proteasome/HDAC inhibitor combination therapy in PEL.
Shruti Bhatt, Brittany M. Ashlock, Ngoc L. Toomey, Luis A. Diaz, Enrique A. Mesri, Izidore S. Lossos, Juan Carlos Ramos
Viral vector–based vaccines that induce protective CD8+ T cell immunity can prevent or control pathogenic SIV infections, but issues of preexisting immunity and safety have impeded their implementation in HIV-1. Here, we report the development of what we believe to be a novel antigen-targeting DNA vaccine strategy that exploits the binding of programmed death-1 (PD1) to its ligands expressed on dendritic cells (DCs) by fusing soluble PD1 with HIV-1 GAG p24 antigen. As compared with non–DC-targeting vaccines, intramuscular immunization via electroporation (EP) of the fusion DNA in mice elicited consistently high frequencies of GAG-specific, broadly reactive, polyfunctional, long-lived, and cytotoxic CD8+ T cells and robust anti-GAG antibody titers. Vaccination conferred remarkable protection against mucosal challenge with vaccinia GAG viruses. Soluble PD1–based vaccination potentiated CD8+ T cell responses by enhancing antigen binding and uptake in DCs and activation in the draining lymph node. It also increased IL-12–producing DCs and engaged antigen cross-presentation when compared with anti-DEC205 antibody-mediated DC targeting. The high frequency of durable and protective GAG-specific CD8+ T cell immunity induced by soluble PD1–based vaccination suggests that PD1-based DNA vaccines could potentially be used against HIV-1 and other pathogens.
Jingying Zhou, Allen K.L. Cheung, Zhiwu Tan, Haibo Wang, Wenbo Yu, Yanhua Du, Yuanxi Kang, Xiaofan Lu, Li Liu, Kwok-Yung Yuen, Zhiwei Chen
To explore the physiological functions of endothelin-2 (ET-2), we generated gene-targeted mouse models. Global
Inik Chang, Alexa N. Bramall, Amy Greenstein Baynash, Amir Rattner, Dinesh Rakheja, Martin Post, Stephen Joza, Colin McKerlie, Duncan J. Stewart, Roderick R. McInnes, Masashi Yanagisawa
Current strategies to suppress graft-versus-host disease (GVHD) also compromise graft-versus-tumor (GVT) responses. Furthermore, most experimental strategies to separate GVHD and GVT responses merely spare GVT function without actually enhancing it. We have previously shown that endogenously expressed TNF-related apoptosis-inducing ligand (TRAIL) is required for optimal GVT activity against certain malignancies in recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT). In order to model a donor-derived cellular therapy, we genetically engineered T cells to overexpress TRAIL and adoptively transferred donor-type unsorted TRAIL+ T cells into mouse models of allo-HSCT. We found that murine TRAIL+ T cells induced apoptosis of alloreactive T cells, thereby reducing GVHD in a DR5-dependent manner. Furthermore, murine TRAIL+ T cells mediated enhanced in vitro and in vivo antilymphoma GVT response. Moreover, human TRAIL+ T cells mediated enhanced in vitro cytotoxicity against both human leukemia cell lines and against freshly isolated chronic lymphocytic leukemia (CLL) cells. Finally, as a model of off-the-shelf, donor-unrestricted antitumor cellular therapy, in vitro#x02013;generated TRAIL+ precursor T cells from third-party donors also mediated enhanced GVT response in the absence of GVHD. These data indicate that TRAIL-overexpressing donor T cells could potentially enhance the curative potential of allo-HSCT by increasing GVT response and suppressing GVHD.
Arnab Ghosh, Yildirim Dogan, Maxim Moroz, Amanda M. Holland, Nury L. Yim, Uttam K. Rao, Lauren F. Young, Daniel Tannenbaum, Durva Masih, Enrico Velardi, Jennifer J. Tsai, Robert R. Jenq, Olaf Penack, Alan M. Hanash, Odette M. Smith, Kelly Piersanti, Cecilia Lezcano, George F. Murphy, Chen Liu, M. Lia Palomba, Martin G. Sauer, Michel Sadelain, Vladimir Ponomarev, Marcel R.M. van den Brink
The migration of effector or memory T cells to the graft is a critical event in the rejection of transplanted organs. The prevailing view is that the key steps involved in T cell migration — integrin-mediated firm adhesion followed by transendothelial migration — are dependent on the activation of Gαi-coupled chemokine receptors on T cells. In contrast to this view, we demonstrated in vivo that cognate antigen was necessary for the firm adhesion and transendothelial migration of CD8+ effector T cells specific to graft antigens and that both steps occurred independent of Gαi signaling. Presentation of cognate antigen by either graft endothelial cells or bone marrow–derived APCs that extend into the capillary lumen was sufficient for T cell migration. The adhesion and transmigration of antigen-nonspecific (bystander) effector T cells, on the other hand, remained dependent on Gαi, but required the presence of antigen-specific effector T cells. These findings underscore the primary role of cognate antigen presented by either endothelial cells or bone marrow–derived APCs in the migration of T cells across endothelial barriers and have important implications for the prevention and treatment of graft rejection.
Jeffrey M. Walch, Qiang Zeng, Qi Li, Martin H. Oberbarnscheidt, Rosemary A. Hoffman, Amanda L. Williams, David M. Rothstein, Warren D. Shlomchik, Jiyun V. Kim, Geoffrey Camirand, Fadi G. Lakkis
Luther A. Bartelt, James Roche, Glynis Kolling, David Bolick, Francisco Noronha, Caitlin Naylor, Paul Hoffman, Cirle Warren, Steven Singer, Richard Guerrant
Cystic fibrosis (CF) pigs develop disease with features remarkably similar to those in people with CF, including exocrine pancreatic destruction, focal biliary cirrhosis, micro-gallbladder, vas deferens loss, airway disease, and meconium ileus. Whereas meconium ileus occurs in 15% of babies with CF, the penetrance is 100% in newborn CF pigs. We hypothesized that transgenic expression of porcine CF transmembrane conductance regulator (
David A. Stoltz, Tatiana Rokhlina, Sarah E. Ernst, Alejandro A. Pezzulo, Lynda S. Ostedgaard, Philip H. Karp, Melissa S. Samuel, Leah R. Reznikov, Michael V. Rector, Nicholas D. Gansemer, Drake C. Bouzek, Mahmoud H. Abou Alaiwa, Mark J. Hoegger, Paula S. Ludwig, Peter J. Taft, Tanner J. Wallen, Christine Wohlford-Lenane, James D. McMenimen, Jeng-Haur Chen, Katrina L. Bogan, Ryan J. Adam, Emma E. Hornick, George A. Nelson IV, Eric A. Hoffman, Eugene H. Chang, Joseph Zabner, Paul B. McCray Jr., Randall S. Prather, David K. Meyerholz, Michael J. Welsh
MicroRNAs (miRNAs) are excellent tumor biomarkers because of their cell-type specificity and abundance. However, many miRNA detection methods, such as real-time PCR, obliterate valuable visuospatial information in tissue samples. To enable miRNA visualization in formalin-fixed paraffin-embedded (FFPE) tissues, we developed multicolor miRNA FISH. As a proof of concept, we used this method to differentiate two skin tumors, basal cell carcinoma (BCC) and Merkel cell carcinoma (MCC), with overlapping histologic features but distinct cellular origins. Using sequencing-based miRNA profiling and discriminant analysis, we identified the tumor-specific miRNAs miR-205 and miR-375 in BCC and MCC, respectively. We addressed three major shortcomings in miRNA FISH, identifying optimal conditions for miRNA fixation and ribosomal RNA (rRNA) retention using model compounds and high-pressure liquid chromatography (HPLC) analyses, enhancing signal amplification and detection by increasing probe-hapten linker lengths, and improving probe specificity using shortened probes with minimal rRNA sequence complementarity. We validated our method on 4 BCC and 12 MCC tumors. Amplified miR-205 and miR-375 signals were normalized against directly detectable reference rRNA signals. Tumors were classified using predefined cutoff values, and all were correctly identified in blinded analysis. Our study establishes a reliable miRNA FISH technique for parallel visualization of differentially expressed miRNAs in FFPE tumor tissues.
Neil Renwick, Pavol Cekan, Paul A. Masry, Sean E. McGeary, Jason B. Miller, Markus Hafner, Zhen Li, Aleksandra Mihailovic, Pavel Morozov, Miguel Brown, Tasos Gogakos, Mehrpouya B. Mobin, Einar L. Snorrason, Harriet E. Feilotter, Xiao Zhang, Clifford S. Perlis, Hong Wu, Mayte Suárez-Fariñas, Huichen Feng, Masahiro Shuda, Patrick S. Moore, Victor A. Tron, Yuan Chang, Thomas Tuschl
Some solid tumors have reduced posttranscriptional RNA editing by adenosine deaminase acting on RNA (ADAR) enzymes, but the functional significance of this alteration has been unclear. Here, we found the primary RNA-editing enzyme ADAR1 is frequently reduced in metastatic melanomas. In situ analysis of melanoma samples using progression tissue microarrays indicated a substantial downregulation of ADAR1 during the metastatic transition. Further, ADAR1 knockdown altered cell morphology, promoted in vitro proliferation, and markedly enhanced the tumorigenicity in vivo. A comparative whole genome expression microarray analysis revealed that ADAR1 controls the expression of more than 100 microRNAs (miRNAs) that regulate many genes associated with the observed phenotypes. Importantly, we discovered that ADAR1 fundamentally regulates miRNA processing in an RNA binding–dependent, yet RNA editing–independent manner by regulating Dicer expression at the translational level via let-7. In addition, ADAR1 formed a complex with DGCR8 that was mutually exclusive with the DGCR8-Drosha complex that processes pri-miRNAs in the nucleus. We found that cancer cells silence
Yael Nemlich, Eyal Greenberg, Rona Ortenberg, Michal J. Besser, Iris Barshack, Jasmine Jacob-Hirsch, Elad Jacoby, Eran Eyal, Ludmila Rivkin, Victor G. Prieto, Nitin Chakravarti, Lyn M. Duncan, David M. Kallenberg, Eitan Galun, Dorothy C. Bennett, Ninette Amariglio, Menashe Bar-Eli, Jacob Schachter, Gideon Rechavi, Gal Markel
Adult-onset autosomal-dominant leukodystrophy (ADLD) is a progressive and fatal
neurological disorder characterized by early autonomic dysfunction, cognitive
impairment, pyramidal tract and cerebellar dysfunction, and white matter loss in the
central nervous system. ADLD is caused by duplication of the
Mary Y. Heng, Shu-Ting Lin, Laure Verret, Yong Huang, Sherry Kamiya, Quasar S. Padiath, Ying Tong, Jorge J. Palop, Eric J. Huang, Louis J. Ptáček, Ying-Hui Fu
Iciar Aviles-Olmos, John Dickson, Zinovia Kefalopoulou, Atbin Djamshidian, Peter Ell, Therese Soderlund, Peter Whitton, Richard Wyse, Tom Isaacs, Andrew Lees, Patricia Limousin, Thomas Foltynie
Multiple sclerosis (MS) is a genetically mediated autoimmune disease of the central nervous system. B cells have recently emerged as major contributors to disease pathogenesis, but the mechanisms responsible for the loss of B cell tolerance in patients with MS are largely unknown. In healthy individuals, developing autoreactive B cells are removed from the repertoire at 2 tolerance checkpoints during early B cell development. Both of these central and peripheral B cell tolerance checkpoints are defective in patients with rheumatoid arthritis (RA) and type 1 diabetes (T1D). Here, we found that only the peripheral, but not the central, B cell tolerance checkpoint is defective in patients with MS. We show that this specific defect is accompanied by increased activation and homeostatic proliferation of mature naive B cells. Interestingly, all of these MS features parallel defects observed in FOXP3-deficient IPEX patients, who harbor nonfunctional Tregs. We demonstrate that in contrast to patients with RA or T1D, bone marrow central B cell selection in MS appears normal in most patients. In contrast, patients with MS suffer from a specific peripheral B cell tolerance defect that is potentially attributable to impaired Treg function and that leads to the accumulation of autoreactive B cell clones in their blood.
Tuure Kinnunen, Nicolas Chamberlain, Henner Morbach, Tineke Cantaert, Megan Lynch, Paula Preston-Hurlburt, Kevan C. Herold, David A. Hafler, Kevin C. O’Connor, Eric Meffre
The heparan sulfate proteoglycan (HSPG) syndecan-1 (SDC1) acts as a major receptor for triglyceride-rich lipoprotein (TRL) clearance in the liver. We sought to identify the relevant apolipoproteins on TRLs that mediate binding to SDC1 and determine their clinical relevance. Evidence supporting ApoE as a major determinant arose from its enrichment in TRLs from mice defective in hepatic heparan sulfate (
Jon C. Gonzales, Philip L.S.M. Gordts, Erin M. Foley, Jeffrey D. Esko
Edward J. Weinman, Rajat S. Biswas, Quihong Peng, Lily Shen, Christina L. Turner, Xiaofei E, Deborah Steplock, Shirish Shenolikar, Rochelle Cunningham