142 results on '"Lopez, Angel"'
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2. An overview on charging tariff schemes and incentives: the eCharge4Drivers project
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Roca, Jaume, Lopez, Angel, Karfopoulos, Evangelos, and Amditis, Angelos
- Abstract
This paper provides an overview of the charging tariffs and e-mobility schemes adopted in different EU cities based on a survey conducted within the EU project eCharge4Drivers. The outcomes of the survey are presented and analysed in order to extract a generalised tariffication formula which allows any eMobility Service Providers (eMSPs) or Charging Point Operators (CPOs) to explore different options to overcome the issues that might affect their CP management strategy. In conclusion, guidelines on how this formula can be adjusted to serve a variety of daily operational and planning needs of eMSPs and CPOs are provided.
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- 2023
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3. The Light that Binds: A Study in Thomas Aquinas's Metaphysics of the Natural Law by Stephen Brock (review)
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Perez-Lopez, Angel
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- 2022
4. Catholic Conscience and Civil Disobedience: The Primacy of Truth
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Perez-Lopez, Angel and Perez-Lopez, Israel
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- 2022
5. Accelerated Closure of Diabetic Wounds by Efficient Recruitment of Fibroblasts upon Inhibiting a 14-3-3/ROCK Regulatory Axis
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Johan, M. Zahied, Pyne, Natasha T., Kolesnikoff, Natasha, Poltavets, Valentina, Esmaeili, Zahra, Woodcock, Joanna M., Lopez, Angel F., Cowin, Allison J., Pitson, Stuart M., and Samuel, Michael S.
- Abstract
Chronic non-healing wounds negatively impact quality of life and are a significant financial drain on health systems. The risk of infection that exacerbates comorbidities in patients necessitates regular application of wound care. Understanding the mechanisms underlying impaired wound healing are therefore a key priority to inform effective new-generation treatments. In this study, we demonstrate that 14-3-3–mediated suppression of signaling through ROCK is a critical mechanism that inhibits the healing of diabetic wounds. Accordingly, pharmacological inhibition of 14-3-3 by topical application of the sphingo-mimetic drug RB-11 to diabetic wounds on a mouse model of type II diabetes accelerated wound closure more than 2-fold than vehicle control, phenocopying our previous observations in 14-3-3ζ–knockout mice. We also demonstrate that accelerated closure of the wounded epidermis by 14-3-3 inhibition causes enhanced signaling through the Rho–ROCK pathway and that the underlying cellular mechanism involves the efficient recruitment of dermal fibroblasts into the wound and the rapid production of extracellular matrix proteins to re-establish the injured dermis. Our observations that the 14-3-3/ROCK inhibitory axis characterizes impaired wound healing and that its suppression facilitates fibroblast recruitment and accelerated re-epithelialization suggest new possibilities for treating diabetic wounds by pharmacologically targeting this axis.
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- 2024
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6. Crystalline Molecular Assemblies of Complexes Showing Eightfold Coordinated Niobium(IV) Dodecahedral Geometry in the Pyridine-Dicarboxylic Acid System
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Andriotou, Despoina, Duval, Sylvain, Volkringer, Christophe, Arevalo-Lopez, Angel M., Simon, Pardis, Vezin, Hervé, and Loiseau, Thierry
- Abstract
The reactivity of 2,3-pyridine-dicarboxylic (known as quinolinic or H2qui) acid and 2,5-pyridine-dicarboxylic (known as isocinchomeronic or H2icc) acid has been investigated as a complexing agent toward the niobium(IV) tetrachloride precursor (NbCl4·2THF) in different organic solvent mixtures. It resulted in the isolation of four crystalline assemblies of mononuclear coordination complexes 1–4[Nb(HL)4·solvent], where HL is the monoprotonated quinolinate (Hqui) ligand (complexes 1–3) or the monoprotonated isocinchomeronate ligand (complex 4). For each complex, the discrete niobium(IV) center is eightfold coordinated to four oxygen atoms from the deprotonated carboxylate arm and four nitrogen atoms from the pyridine part of the dicarboxyl ligand with a dodecahedral environment [NbO4N4]. The remaining carboxyl arm (either in 3 or in 5 position) remained under its protonated form, leading to neutral [Nb(HL)4] moieties for compounds 1, 2, and 4, or the anionic [Nb(qui)(Hqui)3]−moiety for compound 3. The complexes are observed in various molecular arrangements, involving intercalated solvent molecules such as acetonitrile in compound 1([Nb(Hqui)4·0.8(CH3CN)], obtained at room temperature), a mixture of acetonitrile and pyridine in compound 2([Nb(Hqui)4·0.7CH3CN·2PYR], obtained via the solvothermal reaction at 80 °C), a mixture of pyridine and triethylamine, in addition with water and chloride species, in compound 3 ([Nb(qui)(Hqui)3·Cl·HPYR·HTEA·1.5H2O], obtained via solvothermal reaction at 80 °C), and N,N-dimethylformamide in compound 4([Nb(Hicc)4·6DMF], obtained at room temperature). The d1configuration expected for the niobium(IV) centers has been analyzed by magnetic measurements, as well as by EPR and XPS. An anti-ferromagnetism transition has been observed at very low temperatures for complexes 1(3.6 K) and 4(3.3 K), for which the shortest Nb···Nb interatomic lengths occur.
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- 2022
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7. The use of sex pheromones for the knowledge and management of 'white grub guilds' in Mexico/Uso de feromonas sexuales para el conocimiento y manejo de los 'ensambles gallina ciega' en Mexico/Uso de feromonas sexuais para o conhecimento manejo dos 'ensembles pao de galinha' no Mexico
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Alonso Romero-Lopez, Angel
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- 2012
8. Disparities in seasonal influenza vaccine uptake and language preference among Hispanic US adults: an analysis of the 2017–2020 BRFSS
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Perkins, Del, Giron Lopez, Angel, Balcerak, Gregory, Greiner, Benjamin, and Hartwell, Micah
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- 2022
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9. The Human Intellect as the Natural Herald of a Natural Divine Institution
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Perez-Lopez, Angel
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- 2022
10. TLR7gain-of-function genetic variation causes human lupus
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Brown, Grant J., Cañete, Pablo F., Wang, Hao, Medhavy, Arti, Bones, Josiah, Roco, Jonathan A., He, Yuke, Qin, Yuting, Cappello, Jean, Ellyard, Julia I., Bassett, Katharine, Shen, Qian, Burgio, Gaetan, Zhang, Yaoyuan, Turnbull, Cynthia, Meng, Xiangpeng, Wu, Phil, Cho, Eun, Miosge, Lisa A., Andrews, T. Daniel, Field, Matt A., Tvorogov, Denis, Lopez, Angel F., Babon, Jeffrey J., López, Cristina Aparicio, Gónzalez-Murillo, África, Garulo, Daniel Clemente, Pascual, Virginia, Levy, Tess, Mallack, Eric J., Calame, Daniel G., Lotze, Timothy, Lupski, James R., Ding, Huihua, Ullah, Tomalika R., Walters, Giles D., Koina, Mark E., Cook, Matthew C., Shen, Nan, de Lucas Collantes, Carmen, Corry, Ben, Gantier, Michael P., Athanasopoulos, Vicki, and Vinuesa, Carola G.
- Abstract
Although circumstantial evidence supports enhanced Toll-like receptor 7 (TLR7) signalling as a mechanism of human systemic autoimmune disease1–7, evidence of lupus-causing TLR7gene variants is lacking. Here we describe human systemic lupus erythematosus caused by a TLR7gain-of-function variant. TLR7 is a sensor of viral RNA8,9and binds to guanosine10–12. We identified a de novo, previously undescribed missense TLR7Y264Hvariant in a child with severe lupus and additional variants in other patients with lupus. The TLR7Y264Hvariant selectively increased sensing of guanosine and 2',3'-cGMP10–12, and was sufficient to cause lupus when introduced into mice. We show that enhanced TLR7 signalling drives aberrant survival of B cell receptor (BCR)-activated B cells, and in a cell-intrinsic manner, accumulation of CD11c+age-associated B cells and germinal centre B cells. Follicular and extrafollicular helper T cells were also increased but these phenotypes were cell-extrinsic. Deficiency of MyD88 (an adaptor protein downstream of TLR7) rescued autoimmunity, aberrant B cell survival, and all cellular and serological phenotypes. Despite prominent spontaneous germinal-centre formation in Tlr7Y264Hmice, autoimmunity was not ameliorated by germinal-centre deficiency, suggesting an extrafollicular origin of pathogenic B cells. We establish the importance of TLR7 and guanosine-containing self-ligands for human lupus pathogenesis, which paves the way for therapeutic TLR7 or MyD88 inhibition.
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- 2022
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11. Synthesis of the Cannabimovone and Cannabifuran Class of Minor Phytocannabinoids and Their Anti-inflammatory Activity
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Dennis, David G., Anand, Shravanthi D., Lopez, Angel J., Petrovčič, Jan, Das, Aditi, and Sarlah, David
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Despite centuries-long use of Cannabisin human culture and the now ubiquitous claims of its medicinal value, only a small handful of phytocannabinoids have been rigorously evaluated for pharmacological properties. While more than 100 distinct minor cannabinoids have been documented to date, a paucity of studies on their biological activities have been conducted due to a lack of routine access to sufficient quantities for testing. Herein, we report a strategy to prepare several structurally diverse minor cannabinoids deriving synthetically from readily available cannabidiol. Furthermore, we examined their ability to polarize activated microglia toward an anti-inflammatory phenotype using LPS-stimulated BV2 microglial cells. The minor cannabinoids studied, especially cannabielsoin, dehydrocannabielsoin, cannabimovone, and 3′-epicannabimovone, inhibited the production of prototypical pro-inflammatory biomarkers. This study represents the beginning of a systematic mapping of the roles minor cannabinoids may play in the medicinal properties of cannabis used for the treatment of pain and inflammation.
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- 2022
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12. A study of petrol consumption using Spanish panel data
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Labeaga, Jose M. and Lopez, Angel
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Petroleum -- Purchasing ,Consumption (Economics) -- Models ,Business ,Business, general ,Economics - Abstract
I. INTRODUCTION There are some important questions that need to be considered when analysing the demand equations for harmful or contaminating goods (tobacco, alcohol, petrol, carbon, etc.). First of all, [...]
- Published
- 1997
13. ROCK-mediated selective activation of PERK signalling causes fibroblast reprogramming and tumour progression through a CRELD2-dependent mechanism
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Boyle, Sarah Theresa, Poltavets, Valentina, Kular, Jasreen, Pyne, Natasha Theresa, Sandow, Jarrod John, Lewis, Alexander Charles, Murphy, Kendelle Joan, Kolesnikoff, Natasha, Moretti, Paul Andre Bartholomew, Tea, Melinda Nay, Tergaonkar, Vinay, Timpson, Paul, Pitson, Stuart Maxwell, Webb, Andrew Ian, Whitfield, Robert John, Lopez, Angel Francisco, Kochetkova, Marina, and Samuel, Michael Susithiran
- Abstract
It is well accepted that cancers co-opt the microenvironment for their growth. However, the molecular mechanisms that underlie cancer–microenvironment interactions are still poorly defined. Here, we show that Rho-associated kinase (ROCK) in the mammary tumour epithelium selectively actuates protein-kinase-R-like endoplasmic reticulum kinase (PERK), causing the recruitment and persistent education of tumour-promoting cancer-associated fibroblasts (CAFs), which are part of the cancer microenvironment. An analysis of tumours from patients and mice reveals that cysteine-rich with EGF-like domains 2 (CRELD2) is the paracrine factor that underlies PERK-mediated CAF education downstream of ROCK. We find that CRELD2is regulated by PERK-regulated ATF4, and depleting CRELD2 suppressed tumour progression, demonstrating that the paracrine ROCK–PERK–ATF4–CRELD2 axis promotes the progression of breast cancer, with implications for cancer therapy.
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- 2020
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14. Oxysulfide Ba5(VO2S2)2(S2)2Combining Disulfide Channels and Mixed-Anion Tetrahedra and Its Third-Harmonic-Generation Properties
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Almoussawi, Batoul, Huvé, Marielle, Dupray, Valérie, Clevers, Simon, Duffort, Victor, Mentré, Olivier, Roussel, Pascal, Arevalo-Lopez, Angel M., and Kabbour, Houria
- Abstract
Mixed-anion compounds are among the most promising systems to design functional materials with enhanced properties. In particular, heteroleptic environments around transition metals allow tuning of the polarity or band-gap engineering for instance. We present the original oxysulfide Ba5(VO2S2)2(S2)2, the fifth member in the quaternary system Ba–V–S–O. It exhibits the mixed-anion building units V5+O2S2and isolated disulfide pairs (S2)2–. The structure is solved by combining single-crystal and powder X-ray diffraction and transmission electron microscopy. First-principles calculations were combined in order to highlight the anion roles. In particular, our density functional theory study shows that the 3p states of the disulfide pairs dictate the band gap. In this study, we point out anionictools for band-gap engineering that can be useful for the design of phases for numerous applications. Finally, third harmonic generation (THG) was measured and compared to the large THG observed for Cu2O, which reveals the potential for nonlinear-optical properties that should be further investigated.
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- 2020
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15. Sequential Spin State Transition and Intermetallic Charge Transfer in PbCoO3
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Liu, Zhehong, Sakai, Yuki, Yang, Junye, Li, Wenmin, Liu, Ying, Ye, Xubin, Qin, Shijun, Chen, Jinming, Agrestini, Stefano, Chen, Kai, Liao, Sheng-Chieh, Haw, Shu-Chih, Baudelet, Francois, Ishii, Hirofumi, Nishikubo, Takumi, Ishizaki, Hayato, Yamamoto, Tatsuru, Pan, Zhao, Fukuda, Masayuki, Ohashi, Kotaro, Matsuno, Kana, Machida, Akihiko, Watanuki, Tetsu, Kawaguchi, Saori I., Arevalo-Lopez, Angel M., Jin, Changqing, Hu, Zhiwei, Attfield, J. Paul, Azuma, Masaki, and Long, Youwen
- Abstract
Spin state transitions and intermetallic charge transfers can essentially change material structural and physical properties while excluding external chemical doping. However, these two effects have rarely been found to occur sequentially in a specific material. In this article, we show the realization of these two phenomena in a perovskite oxide PbCoO3with a simple ABO3composition under high pressure. PbCoO3possesses a peculiar A- and B-site ordered charge distribution Pb2+Pb4+3Co2+2Co3+2O12with insulating behavior at ambient conditions. The high spin Co2+gradually changes to low spin with increasing pressure up to about 15 GPa, leading to an anomalous increase of resistance magnitude. Between 15 and 30 GPa, the intermetallic charge transfer occurs between Pb4+and Co2+cations. The accumulated charge-transfer effect triggers a metal–insulator transition as well as a first-order structural phase transition toward a Tetra.-I phase at the onset of ∼20 GPa near room temperature. On further compression over 30 GPa, the charge transfer completes, giving rise to another first-order structural transformation toward a Tetra.-II phase and the reentrant electrical insulating behavior.
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- 2020
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16. Elucidating the Mechanism of Metabolism of Cannabichromene by Human Cytochrome P450s
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Roy, Pritam, Maturano, Jonathan, Hasdemir, Hale, Lopez, Angel, Xu, Fengyun, Hellman, Judith, Tajkhorshid, Emad, Sarlah, David, and Das, Aditi
- Abstract
Cannabichromene (CBC) is a nonpsychoactive phytocannabinoid well-known for its wide-ranging health advantages. However, there is limited knowledge regarding its human metabolism following CBC consumption. This research aimed to explore the metabolic pathways of CBC by various human liver cytochrome P450 (CYP) enzymes and support the outcomes using in vivodata from mice. The results unveiled two principal CBC metabolites generated by CYPs: 8′-hydroxy-CBC and 6′,7′-epoxy-CBC, along with a minor quantity of 1″-hydroxy-CBC. Notably, among the examined CYPs, CYP2C9 demonstrated the highest efficiency in producing these metabolites. Moreover, through a molecular dynamics simulation spanning 1 μs, it was observed that CBC attains stability at the active site of CYP2J2 by forming hydrogen bonds with I487 and N379, facilitated by water molecules, which specifically promotes the hydroxy metabolite’s formation. Additionally, the presence of cytochrome P450 reductase (CPR) amplified CBC’s binding affinity to CYPs, particularly with CYP2C8 and CYP3A4. Furthermore, the metabolites derived from CBC reduced cytokine levels, such as IL6 and NO, by approximately 50% in microglia cells. This investigation offers valuable insights into the biotransformation of CBC, underscoring the physiological importance and the potential significance of these metabolites.
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- 2024
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17. Donor T-cell–derived GM-CSF drives alloantigen presentation by dendritic cells in the gastrointestinal tract
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Gartlan, Kate H., Koyama, Motoko, Lineburg, Katie E., Chang, Karshing, Ensbey, Kathleen S., Kuns, Rachel D., Henden, Andrea S., Samson, Luke D., Clouston, Andrew D., Lopez, Angel F., MacDonald, Kelli P. A., and Hill, Geoffrey R.
- Abstract
Granulocyte-macrophage colony-stimulating factor (GM-CSF) has recently emerged as an important pathogenic cytokine in acute graft-versus-host disease (GVHD), but the nature of the T-cell lineages secreting the cytokine and the mechanisms of action are less clear. Here we used interleukin 17A-fate reporter systems with transcriptional analysis and assays of alloantigen presentation to interrogate the origins of GM-CSF–secreting T cells and the effects of the cytokine on antigen-presenting cell (APC) function after experimental allogeneic stem cell transplantation (SCT). We demonstrated that although GM-CSF-secreting Th17 and non-Th17 cells expanded in the colon over time after SCT, the Th17 lineage expanded to represent 10% to 20% of the GM-CSF secreting T cells at this site by 4 weeks. Donor T-cell-derived GM-CSF expanded alloantigen-presenting donor dendritic cells (DCs) in the colon and lymph nodes. In the mesenteric lymph nodes, GM-CSF–dependent DCs primed donor T cells and amplified acute GVHD in the colon. We thus describe a feed-forward cascade whereby GM-CSF–secreting donor T cells accumulate and drive alloantigen presentation in the colon to amplify GVHD severity. GM-CSF inhibition may be a tractable clinical intervention to limit donor alloantigen presentation and GVHD in the lower gastrointestinal tract.
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- 2019
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18. Metamagnetic Transitions versus Magnetocrystalline Anisotropy in Two Cobalt Arsenates with 1D Co2+Chains
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Leclercq, Bastien, Kabbour, Houria, Damay, Françoise, Colin, Claire V., Pautrat, Alain, Arevalo-Lopez, Angel M., and Mentré, Olivier
- Abstract
We have investigated two original hydrated cobalt arsenates based on Co2+octahedral edge-sharing chains. Their different magnetocrystalline anisotropies induce different types of metamagnetic transitions: spin-flop versus spin-flip. In both compounds, a strong local anisotropy (Ising spins) is favored by the spin–orbit coupling present in the CoO6octahedra, while ferromagnetic (FM) exchanges predominate in the chains. Co2(As2O7)·2H2O (1) orders antiferromagnetically below TN= 6.7 K. The magnetic structure is a noncollinear antiferromagnetic spin arrangement along the zigzag chains with DFT calculations implying frustrated chains and weakened anisotropy. A metamagnetic transition suggests a spin-flop process above μ0H= 3.2 T. In contrast, in BaCo2As2O8·2H2O (2) linear chains are arranged in disconnected layers, with only interchain ferromagnetic exchanges, therefore increasing its magnetocrystalline anisotropy. The magnetic structure is collinear with a magnetic easy axis that allows a spin-flop to a sharp spin-flip transition below TN= 15.1 K and above μ0H = 6.2 T.
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- 2019
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19. Regulatory roles of IL-10–producing human follicular T cells
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Cañete, Pablo F., Sweet, Rebecca A., Gonzalez-Figueroa, Paula, Papa, Ilenia, Ohkura, Naganari, Bolton, Holly, Roco, Jonathan A., Cuenca, Marta, Bassett, Katharine J., Sayin, Ismail, Barry, Emma, Lopez, Angel, Canaday, David H., Meyer-Hermann, Michael, Doglioni, Claudio, Fazekas de St Groth, Barbara, Sakaguchi, Shimon, Cook, Matthew C., and Vinuesa, Carola G.
- Abstract
Mucosal lymphoid tissues such as human tonsil are colonized by bacteria and exposed to ingested and inhaled antigens, requiring tight regulation of immune responses. Antibody responses are regulated by follicular helper T (TFH) cells and FOXP3+ follicular regulatory T (TFR) cells. Here we describe a subset of human tonsillar follicular T cells identified by expression of TFH markers and CD25 that are the main source of follicular T (TF) cell–derived IL-10. Despite lack of FOXP3 expression, CD25+ TF cells resemble T reg cells in high CTLA4 expression, low IL-2 production, and their ability to repress T cell proliferation. CD25+ TF cell–derived IL-10 dampens induction of B cell class-switching to IgE. In children, circulating total IgE titers were inversely correlated with the frequencies of tonsil CD25+ TF cells and IL-10–producing TF cells but not with total T reg cells, TFR, or IL-10–producing T cells. Thus, CD25+ TF cells emerge as a subset with unique T and B cell regulatory activities that may help prevent atopy.
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- 2019
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20. Veritatis Splendor and Amoris Laetitia: Neither Lamented nor Celebrated Discontinuity
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Perez-Lopez, Angel
- Published
- 2018
21. The mechanism of GM-CSF inhibition by human GM-CSF auto-antibodies suggests novel therapeutic opportunities
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Dhagat, Urmi, Hercus, Timothy R., Broughton, Sophie E., Nero, Tracy L., Cheung Tung Shing, Karen S., Barry, Emma F., Thomson, Christy A., Bryson, Steve, Pai, Emil F., McClure, Barbara J., Schrader, John W., Lopez, Angel F., and Parker, Michael W.
- Abstract
ABSTRACTGranulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor that can stimulate a variety of cells, but its overexpression leads to excessive production and activation of granulocytes and macrophages with many pathogenic effects. This cytokine is a therapeutic target in inflammatory diseases, and several anti-GM-CSF antibodies have advanced to Phase 2 clinical trials in patients with such diseases, e.g., rheumatoid arthritis. GM-CSF is also an essential factor in preventing pulmonary alveolar proteinosis (PAP), a disease associated with GM-CSF malfunction arising most typically through the presence of GM-CSF neutralizing auto-antibodies. Understanding the mechanism of action for neutralizing antibodies that target GM-CSF is important for improving their specificity and affinity as therapeutics and, conversely, in devising strategies to reduce the effects of GM-CSF auto-antibodies in PAP. We have solved the crystal structures of human GM-CSF bound to antigen-binding fragments of two neutralizing antibodies, the human auto-antibody F1 and the mouse monoclonal antibody 4D4. Coordinates and structure factors of the crystal structures of the GM-CSF:F1 Fab and the GM-CSF:4D4 Fab complexes have been deposited in the RCSB Protein Data Bank under the accession numbers 6BFQ and 6BFS, respectively. The structures show that these antibodies bind to mutually exclusive epitopes on GM-CSF; however, both prevent the cytokine from interacting with its alpha receptor subunit and hence prevent receptor activation. Importantly, identification of the F1 epitope together with functional analyses highlighted modifications to GM-CSF that would abolish auto-antibody recognition whilst retaining GM-CSF function. These results provide a framework for developing novel GM-CSF molecules for PAP treatment and for optimizing current anti-GM-CSF antibodies for use in treating inflammatory disorders.
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- 2018
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22. A multi-cohort study of the immune factors associated with M. tuberculosisinfection outcomes
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Roy Chowdhury, Roshni, Vallania, Francesco, Yang, Qianting, Lopez Angel, Cesar, Darboe, Fatoumatta, Penn-Nicholson, Adam, Rozot, Virginie, Nemes, Elisa, Malherbe, Stephanus, Ronacher, Katharina, Walzl, Gerhard, Hanekom, Willem, Davis, Mark, Winter, Jill, Chen, Xinchun, Scriba, Thomas, Khatri, Purvesh, and Chien, Yueh-hsiu
- Abstract
Most infections with Mycobacterium tuberculosis(Mtb) manifest as a clinically asymptomatic, contained state, known as latent tuberculosis infection, that affects approximately one-quarter of the global population1. Although fewer than one in ten individuals eventually progress to active disease2, tuberculosis is a leading cause of death from infectious disease worldwide3. Despite intense efforts, immune factors that influence the infection outcomes remain poorly defined. Here we used integrated analyses of multiple cohorts to identify stage-specific host responses to Mtbinfection. First, using high-dimensional mass cytometry analyses and functional assays of a cohort of South African adolescents, we show that latent tuberculosis is associated with enhanced cytotoxic responses, which are mostly mediated by CD16 (also known as FcγRIIIa) and natural killer cells, and continuous inflammation coupled with immune deviations in both T and B cell compartments. Next, using cell-type deconvolution of transcriptomic data from several cohorts of different ages, genetic backgrounds, geographical locations and infection stages, we show that although deviations in peripheral B and T cell compartments generally start at latency, they are heterogeneous across cohorts. However, an increase in the abundance of circulating natural killer cells in tuberculosis latency, with a corresponding decrease during active disease and a return to baseline levels upon clinical cure are features that are common to all cohorts. Furthermore, by analysing three longitudinal cohorts, we find that changes in peripheral levels of natural killer cells can inform disease progression and treatment responses, and inversely correlate with the inflammatory state of the lungs of patients with active tuberculosis. Together, our findings offer crucial insights into the underlying pathophysiology of tuberculosis latency, and identify factors that may influence infection outcomes. Integrated analyses of multiple cohorts are used to obtain a better understanding of the immune state of latent infection with Mycobacterium tuberculosis, and factors that mediate and/or predict transitions from latent infection to active disease.
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- 2018
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23. Master class: Tips from the nation's top pros
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Collins, Pete, Lopez, Angel, Cap, Louie, and DeHart, Ken
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Tennis players -- Beliefs, opinions and attitudes ,Tennis -- Doubles ,Tennis -- Methods - Published
- 2007
24. The transcriptional program, functional heterogeneity, and clinical targeting of mast cells
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Cildir, Gökhan, Pant, Harshita, Lopez, Angel F., and Tergaonkar, Vinay
- Abstract
Mast cells are unique tissue-resident immune cells that express an array of receptors that can be activated by several extracellular cues, including antigen–immunoglobulin E (IgE) complexes, bacteria, viruses, cytokines, hormones, peptides, and drugs. Mast cells constitute a small population in tissues, but their extraordinary ability to respond rapidly by releasing granule-stored and newly made mediators underpins their importance in health and disease. In this review, we document the biology of mast cells and introduce new concepts and opinions regarding their role in human diseases beyond IgE-mediated allergic responses and antiparasitic functions. We bring to light recent discoveries and developments in mast cell research, including regulation of mast cell functions, differentiation, survival, and novel mouse models. Finally, we highlight the current and future opportunities for therapeutic intervention of mast cell functions in inflammatory diseases.
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- 2017
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25. High CD123 levels enhance proliferation in response to IL-3, but reduce chemotaxis by downregulating CXCR4 expression
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Wittwer, Nicole L., Brumatti, Gabriela, Marchant, Ceilidh, Sandow, Jarrod J., Pudney, Melanie K., Dottore, Mara, D’Andrea, Richard J., Lopez, Angel F., Ekert, Paul G., and Ramshaw, Hayley S.
- Abstract
High expression of the a chain of the interleukin-3 receptor (IL-3Ra; CD123) is a hallmark of acute myeloid leukemia (AML) leukemic stem cells (LSCs). Elevated CD123 expression is part of the diagnostic immunophenotyping of myeloid leukemia, and higher expression is associated with poor prognosis. However, the biological basis of the poorer prognosis is unclear, and may include heightened IL-3 signaling and non–cell autonomous interactions with the bone marrow (BM) microenvironment. We used TF-1 cells expressing different levels of CD123 and found elevated CD123 levels amplified the proliferative response to exogenous IL-3 and maintained viability in reducing IL-3 concentrations. This was associated with stronger activation of STAT5, Akt, and extracellular signal-regulated kinase 1/2 in vitro. Surprisingly, in vivo e14.5 fetal liver cells transduced with retroviral constructs to express high CD123 failed to engraft in syngeneic recipients. In exploring the underlying mechanism for this, we found that CXCR4, a key molecule involved in LSC/BM interactions, was specifically downregulated in CD123 overexpressing cells in a manner dependent on IL-3 signaling. CXCR4 downregulation was sufficient to alter the chemotactic response of hematopoietic cells to stromal derived factor-1 (SDF-1). Thus, we propose that the overexpression of CD123 in AML LSC dictates their location by altering CXCR4/SDF-1 interaction in the BM, raising the possibility that this mechanism underpins the egress of BM AML LSC and more mature cells into the circulation.
- Published
- 2017
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26. Proteome Analysis of DrosophilaMutants Identifies a Regulatory Role for 14–3–3ε in Metabolic Pathways
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Ng, Yeap S., Sorvina, Alexandra, Bader, Christie A., Weiland, Florian, Lopez, Angel F., Hoffmann, Peter, Shandala, Tetyana, and Brooks, Douglas A.
- Abstract
The evolutionary conserved family of 14–3–3 proteins appears to have a role in integrating numerous intracellular pathways, including signal transduction, intracellular trafficking, and metabolism. However, little is known about how this interactive network might be affected by the direct abrogation of 14–3–3 function. The loss of Drosophila14–3–3ε resulted in reduced survival of mutants during larval-to-adult transition, which is known to depend on an energy supply coming from the histolysis of fat body tissue. Here we report a differential proteomic analysis of larval fat body tissue at the onset of larval-to-adult transition, with the loss of 14–3–3ε resulting in the altered abundance of 16 proteins. These included proteins linked to protein biosynthesis, glycolysis, tricarboxylic acid cycle, and lipid metabolic pathways. The ecdysone receptor (EcR), which is responsible for initiating the larval-to-adult transition, colocalized with 14–3–3ε in wild-type fat body tissues. The altered protein abundance in 14–3–3εmutant fat body tissue was associated with transcriptional deregulation of alcohol dehydrogenase, fat body protein 1, and lamingenes, which are known targets of the EcR. This study indicates that 14–3–3ε has a critical role in cellular metabolism involving either molecular crosstalk with the EcR or direct interaction with metabolic proteins.
- Published
- 2017
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27. Targeting sphingosine kinase 1 induces MCL1-dependent cell death in acute myeloid leukemia
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Powell, Jason A., Lewis, Alexander C., Zhu, Wenying, Toubia, John, Pitman, Melissa R., Wallington-Beddoe, Craig T., Moretti, Paul A. B., Iarossi, Diana, Samaraweera, Saumya E., Cummings, Nik, Ramshaw, Hayley S., Thomas, Daniel, Wei, Andrew H., Lopez, Angel F., D’Andrea, Richard J., Lewis, Ian D., and Pitson, Stuart M.
- Abstract
Acute myeloid leukemia (AML) is an aggressive malignancy where despite improvements in conventional chemotherapy and bone marrow transplantation, overall survival remains poor. Sphingosine kinase 1 (SPHK1) generates the bioactive lipid sphingosine 1-phosphate (S1P) and has established roles in tumor initiation, progression, and chemotherapy resistance in a wide range of cancers. The role and targeting of SPHK1 in primary AML, however, has not been previously investigated. Here we show that SPHK1 is overexpressed and constitutively activated in primary AML patient blasts but not in normal mononuclear cells. Subsequent targeting of SPHK1 induced caspase-dependent cell death in AML cell lines, primary AML patient blasts, and isolated AML patient leukemic progenitor/stem cells, with negligible effects on normal bone marrow CD34+ progenitors from healthy donors. Furthermore, administration of SPHK1 inhibitors to orthotopic AML patient–derived xenografts reduced tumor burden and prolonged overall survival without affecting murine hematopoiesis. SPHK1 inhibition was associated with reduced survival signaling from S1P receptor 2, resulting in selective downregulation of the prosurvival protein MCL1. Subsequent analysis showed that the combination of BH3 mimetics with either SPHK1 inhibition or S1P receptor 2 antagonism triggered synergistic AML cell death. These results support the notion that SPHK1 is a bona fide therapeutic target for the treatment of AML.
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- 2017
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28. A case of multifocal medulloblastoma in an adult patient
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Hernández Cancela, Rose Marie, Pombo Otero, Jorge, and Concha-Lopez, Angel
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Only five cases of multifocal medulloblastoma in the adult have been reported to date.
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- 2017
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29. Ywhaz/14-3-3ζ Deletion Improves Glucose Tolerance Through a GLP-1-Dependent Mechanism
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Lim, Gareth E., Piske, Micah, Lulo, James E., Ramshaw, Hayley S., Lopez, Angel F., and Johnson, James D.
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Multiple signaling pathways mediate the actions of metabolic hormones to control glucose homeostasis, but the proteins that coordinate such networks are poorly understood. We previously identified the molecular scaffold protein, 14-3-3ζ, as a critical regulator of in vitro β-cell survival and adipogenesis, but its metabolic roles in glucose homeostasis have not been studied in depth. Herein, we report that Ywhazgene knockout mice (14-3-3ζKO) exhibited elevated fasting insulin levels while maintaining normal β-cell responsiveness to glucose when compared with wild-type littermate controls. In contrast with our observations after an ip glucose bolus, glucose tolerance was significantly improved in 14-3-3ζKO mice after an oral glucose gavage. This improvement in glucose tolerance was associated with significantly elevated fasting glucagon-like peptide-1 (GLP-1) levels. 14-3-3ζ knockdown in GLUTag L cells elevated GLP-1 synthesis and increased GLP-1 release. Systemic inhibition of the GLP-1 receptor attenuated the improvement in oral glucose tolerance that was seen in 14-3-3ζKO mice. When taken together these findings demonstrate novel roles of 14-3-3ζ in the regulation of glucose homeostasis and suggest that modulating 14-3-3ζ levels in intestinal L cells may have beneficial metabolic effects through GLP-1-dependent mechanisms.
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- 2016
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30. CSL311, a novel, potent, therapeutic monoclonal antibody for the treatment of diseases mediated by the common β chain of the IL-3, GM-CSF and IL-5 receptors
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Panousis, Con, Dhagat, Urmi, Edwards, Kirsten M., Rayzman, Veronika, Hardy, Matthew P., Braley, Hal, Gauvreau, Gail M., Hercus, Timothy R., Smith, Steven, Sehmi, Roma, McMillan, Laura, Dottore, Mara, McClure, Barbara J., Fabri, Louis J., Vairo, Gino, Lopez, Angel F, Parker, Michael W., Nash, Andrew D., Wilson, Nicholas J., Wilson, Michael J., and Owczarek, Catherine M.
- Abstract
ABSTRACTThe β common-signaling cytokines interleukin (IL)-3, granulocyte-macrophage colony stimulating factor (GM-CSF) and IL-5 stimulate pro-inflammatory activities of haematopoietic cells via a receptor complex incorporating cytokine-specific α and shared β common (βc, CD131) receptor. Evidence from animal models and recent clinical trials demonstrate that these cytokines are critical mediators of the pathogenesis of inflammatory airway disease such as asthma. However, no therapeutic agents, other than steroids, that specifically and effectively target inflammation mediated by all 3 of these cytokines exist. We employed phage display technology to identify and optimize a novel, human monoclonal antibody (CSL311) that binds to a unique epitope that is specific to the cytokine-binding site of the human βcreceptor. The binding epitope of CSL311 on the βcreceptor was defined by X-ray crystallography and site-directed mutagenesis. CSL311 has picomolar binding affinity for the human βcreceptor, and at therapeutic concentrations is a highly potent antagonist of the combined activities of IL-3, GM-CSF and IL-5 on primary eosinophil survival in vitro. Importantly, CSL311 inhibited the survival of inflammatory cells present in induced sputum from human allergic asthmatic subjects undergoing allergen bronchoprovocation. Due to its high potency and ability to simultaneously suppress the activity of all 3 β common cytokines, CSL311 may provide a new strategy for the treatment of chronic inflammatory diseases where the human βcreceptor is central to pathogenesis. The coordinates for the βc/CSL311 Fab complex structure have been deposited with the RCSB Protein Data Bank (PDB 5DWU).
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- 2016
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31. Dual Mechanism of Interleukin-3 Receptor Blockade by an Anti-Cancer Antibody
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Broughton, Sophie E., Hercus, Timothy R., Hardy, Matthew P., McClure, Barbara J., Nero, Tracy L., Dottore, Mara, Huynh, Huy, Braley, Hal, Barry, Emma F., Kan, Winnie L., Dhagat, Urmi, Scotney, Pierre, Hartman, Dallas, Busfield, Samantha J., Owczarek, Catherine M., Nash, Andrew D., Wilson, Nicholas J., Parker, Michael W., and Lopez, Angel F.
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Interleukin-3 (IL-3) is an activated T cell product that bridges innate and adaptive immunity and contributes to several immunopathologies. Here, we report the crystal structure of the IL-3 receptor α chain (IL3Rα) in complex with the anti-leukemia antibody CSL362 that reveals the N-terminal domain (NTD), a domain also present in the granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-5, and IL-13 receptors, adopting unique “open” and classical “closed” conformations. Although extensive mutational analyses of the NTD epitope of CSL362 show minor overlap with the IL-3 binding site, CSL362 only inhibits IL-3 binding to the closed conformation, indicating alternative mechanisms for blocking IL-3 signaling. Significantly, whereas “open-like” IL3Rα mutants can simultaneously bind IL-3 and CSL362, CSL362 still prevents the assembly of a higher-order IL-3 receptor-signaling complex. The discovery of open forms of cytokine receptors provides the framework for development of potent antibodies that can achieve a “double hit” cytokine receptor blockade.
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- 2014
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32. Interleukin‐3‐mediated regulation of β‐catenin in myeloid transformation and acute myeloid leukemia
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Sadras, Teresa, Perugini, Michelle, Kok, Chung H., Iarossi, Diana G., Heatley, Susan L., Brumatti, Gabriela, Samuel, Michael S., To, Luen B., Lewis, Ian D., Lopez, Angel F., Ekert, Paul G., Ramshaw, Hayley S., and DˈAndrea, Richard J.
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IL‐3 activates β‐catenin in Hox‐transformed myeloid cells, and primary AML samples, presenting a novel axis for targeted inhibition of β‐catenin in some patients with AML. Aberrant activation of β‐catenin is a common event in AML and is an independent predictor of poor prognosis. Although increased β‐catenin signaling in AML has been associated with oncogenic translocation products and activating mutations in the FLT3R, the mechanisms that activate β‐catenin in AML more broadly are still unclear. Here, we describe a novel link between IL‐3 signaling and the regulation of β‐catenin in myeloid transformation and AML. In a murine model of HoxB8 and IL‐3 cooperation, we show that β‐catenin protein levels are modulated by IL‐3 and that Cre‐induced deletion of β‐catenin abolishes IL‐3‐dependent growth and colony formation. In IL‐3‐dependent leukemic TF‐1.8 cells, we observed increased β‐catenin protein levels and nuclear localization in response to IL‐3, and this correlated with transcriptional induction of β‐catenin target genes. Furthermore, IL‐3 promoted β‐catenin accumulation in a subset of AML patient samples, and gene‐expression profiling of these cells revealed induction of WNT/β‐catenin and TCF4 gene signatures in an IL‐3‐dependent manner. This study is the first to link β‐catenin activation to IL‐3 and suggests that targeting IL‐3 signaling may be an effective approach for the inhibition of β‐catenin activity in some patients with AML.
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- 2014
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33. Monoclonal antibody targeting of IL-3 receptor α with CSL362 effectively depletes CML progenitor and stem cells
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Nievergall, Eva, Ramshaw, Hayley S., Yong, Agnes S. M., Biondo, Mark, Busfield, Samantha J., Vairo, Gino, Lopez, Angel F., Hughes, Timothy P., White, Deborah L., and Hiwase, Devendra K.
- Abstract
Despite the remarkable efficacy of tyrosine kinase inhibitors (TKIs) in eliminating differentiated chronic myeloid leukemia (CML) cells, recent evidence suggests that leukemic stem and progenitor cells (LSPCs) persist long term, which may be partly attributable to cytokine-mediated resistance. We evaluated the expression of the interleukin 3 (IL-3) receptor α subunit (CD123), an established marker of acute myeloid leukemia stem cells, on CML LSPCs and the potential of targeting those cells with the humanized anti-CD123 monoclonal antibody CSL362. Compared with normal donors, CD123 expression was higher in CD34+/CD38– cells of both chronic phase and blast crisis CML patients, with levels increasing upon disease progression. CSL362 effectively targeted CML LSPCs by selective antibody-dependent cell-mediated cytotoxicity (ADCC)–facilitated lysis of CD123+ cells and reduced leukemic engraftment in mice. Importantly, not only were healthy donor allogeneic natural killer (NK) cells able to mount an effective CSL362-mediated ADCC response, but so were CML patients’ autologous NK cells. In addition, CSL362 also neutralized IL-3–mediated rescue of TKI-induced cell death. Notably, combination of TKI- and CSL362-induced ADCC caused even greater reduction of CML progenitors and further augmented their preferential elimination over normal hematopoietic stem and progenitor cells. Thus, our data support the further evaluation of CSL362 therapy in CML.
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- 2014
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34. Targeting acute myeloid leukemia by dual inhibition of PI3K signaling and Cdk9-mediated Mcl-1 transcription
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Thomas, Daniel, Powell, Jason A., Vergez, Francois, Segal, David H., Nguyen, Nhu-Y. N., Baker, Adele, Teh, Tse-Chieh, Barry, Emma F., Sarry, Jean-Emmanuel, Lee, Erwin M., Nero, Tracy L., Jabbour, Anissa M., Pomilio, Giovanna, Green, Benjamin D., Manenti, Stéphane, Glaser, Stefan P., Parker, Michael W., Lopez, Angel F., Ekert, Paul G., Lock, Richard B., Huang, David C. S., Nilsson, Susie K., Récher, Christian, Wei, Andrew H., and Guthridge, Mark A.
- Abstract
Resistance to cell death is a hallmark of cancer and renders transformed cells resistant to multiple apoptotic triggers. The Bcl-2 family member, Mcl-1, is a key driver of cell survival in diverse cancers, including acute myeloid leukemia (AML). A screen for compounds that downregulate Mcl-1 identified the kinase inhibitor, PIK-75, which demonstrates marked proapoptotic activity against a panel of cytogenetically diverse primary human AML patient samples. We show that PIK-75 transiently blocks Cdk7/9, leading to transcriptional suppression of MCL-1, rapid loss of Mcl-1 protein, and alleviation of its inhibition of proapoptotic Bak. PIK-75 also targets the p110α isoform of PI3K, which leads to a loss of association between Bcl-xL and Bak. The simultaneous loss of Mcl-1 and Bcl-xL association with Bak leads to rapid apoptosis of AML cells. Concordantly, low Bak expression in AML confers resistance to PIK-75–mediated killing. On the other hand, the induction of apoptosis by PIK-75 did not require the expression of the BH3 proteins Bim, Bid, Bad, Noxa, or Puma. PIK-75 significantly reduced leukemia burden and increased the survival of mice engrafted with human AML without inducing overt toxicity. Future efforts to cotarget PI3K and Cdk9 with drugs such as PIK-75 in AML are warranted.
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- 2013
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35. Immune insufficiency during GVHD is due to defective antigen presentation within dendritic cell subsets
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Markey, Kate A., Koyama, Motoko, Kuns, Rachel D., Lineburg, Katie E., Wilson, Yana A., Olver, Stuart D., Raffelt, Neil C., Don, Alistair L.J., Varelias, Antiopi, Robb, Renee J., Cheong, Melody, Engwerda, Christian R., Steptoe, Raymond J., Ramshaw, Hayley S., Lopez, Angel F., Vega-Ramos, Javier, Lew, Andrew M., Villadangos, Jose A., Hill, Geoffrey R., and MacDonald, Kelli P.A.
- Abstract
Alloreactivity after transplantation is associated with profound immune suppression, and consequent opportunistic infection results in high morbidity and mortality. This immune suppression is most profound during GVHD after bone marrow transplantation where an inflammatory cytokine storm dominates. Contrary to current dogma, which avers that this is a T-cell defect, we demonstrate that the impairment lies within conventional dendritic cells (cDCs). Significantly, exogenous antigens can only be presented by the CD8−cDC subset after bone marrow transplantation, and inflammation during GVHD specifically renders the MHC class II presentation pathway in this population incompetent. In contrast, both classic and cross-presentation within MHC class I remain largely intact. Importantly, this defect in antigen processing can be partially reversed by TNF inhibition or the adoptive transfer of donor cDCs generated in the absence of inflammation.
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- 2012
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36. High-dynamic-range 4-Mpixel CMOS image sensor for scientific applications
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Vu, Paul, Fowler, Boyd, Liu, Chiao, Mims, Steve, Bartkovjak, Peter, Do, Hung, Li, Wang, Appelbaum, Jeff, and Lopez, Angel
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As bio-technology transitions from research and development to high volume production, dramatic improvements in image sensor performance will be required to support the throughput and cost requirements of this market. This includes higher resolution, higher frame rates, higher quantum efficiencies, increased system integration, lower read-noise, and lower device costs. We present the performance of a recently developed low noise 2048(H) x 2048(V) CMOS image sensor optimized for scientific applications such as life science imaging, microscopy, as well as industrial inspection applications. The sensor architecture consists of two identical halves which can be operated independently and the imaging array consists of 4T pixels with pinned photodiodes on a 6.5m pitch with integrated micro-lens. The operation of the sensor is programmable through a SPI interface. The measured peak quantum efficiency of the sensor is 73% at 600nm, and the read noise is about 1.1e- RMS at 100 fps data rate. The sensor features dual gain column parallel ouput amplifiers with 11-bit single slope ADCs. The full well capacity is greater than 36ke-, the dark current is less than 7pA/cm2at 20°C. The sensor achieves an intra-scene linear dynamic range of greater than 91dB (36000:1) at room temperature.
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- 2012
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37. Plantar Fasciopathy Treated with Dynamic Splinting
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Sheridan, Larry, Lopez, Angel, Perez, Andres, John, Mathew M., Willis, F. Buck, and Shanmugam, Ramalingam
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Background:Plantar fasciopathy (or plantar fasciitis) is considered to be one of the most common foot abnormalities, affecting up to 2 million Americans each year, and the chief complaint is acute heel pain. Therapeutic protocols for this condition have included stretching exercises, corticosteroid injections, physical therapy, and foot orthoses, but a single modality has not been found to be universally effective. We sought to determine the efficacy of stretching with dynamic splinting for the treatment of plantar fasciitis.Methods:Sixty patients (76 feet) were enrolled in this 12-week study from four different clinics across the United States. Patients were randomly categorized into experimental and control groups. All of the patients received nonsteroidal anti-inflammatory drugs, orthoses, and corticosteroid injections if needed. Thirty experimental patients also received dynamic splinting for nightly wear to obtain a low-load, prolonged-duration stretch with dynamic tension. The dependent variable was change from baseline in Plantar Fasciopathy Pain/Disability Scale score, and the independent variable was group (experimental versus control).Results:Two-sample ttests were calculated, and there was a significant difference in the mean change scores of experimental versus control patients (−33 versus −2 points, P< .0001).Conclusions:Dynamic splinting was effective for reducing the pain of plantar fasciopathy, and this modality should be included in the standard of care for treating plantar fasciopathy. (J Am Podiatr Med Assoc 100(3): 161–165, 2010)
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- 2010
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38. Alternative modes of GM-CSF receptor activation revealed using activated mutants of the common β-subunit
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Perugini, Michelle, Brown, Anna L., Salerno, Diana G., Booker, Grant W., Stojkoski, Cvetan, Hercus, Timothy R., Lopez, Angel F., Hibbs, Margaret L., Gonda, Thomas J., and D'Andrea, Richard J.
- Abstract
Granulocyte/macrophage colony-stimulating factor promotes growth, survival, differentiation, and activation of normal myeloid cells and plays an important role in myeloid leukemias. The GM-CSF receptor (GMR) shares a signaling subunit, βc, with interleukin-3 and interleukin-5 receptors and has recently been shown to induce activation of Janus kinase 2 (JAK2) and downstream signaling via formation of a unique dodecameric receptor complex. In this study we use 2 activated βc mutants that display distinct signaling capacity and have differential requirements for the GMR α-subunit (GMR-α) to dissect the signaling pathways associated with the GM-CSF response. The V449E transmembrane mutant selectively activates JAK2/signal transducer and activator of transcription 5 and extracellular signal-regulated kinase (ERK) pathways, resulting in a high level of sensitivity to JAK and ERK inhibitors, whereas the extracellular mutant (FIΔ) selectively activates the phosphoinositide 3-kinase/Akt and IκKβ/nuclear factorκB pathways. We also demonstrate a novel and direct interaction between the SH3 domains of Lyn and Src with a conserved proline-rich motif in GMR-α and show a selective requirement for Src family kinases by the FIΔ mutant. We relate the nonoverlapping nature of signaling by the activated mutants to the structure of the unique GMR complex and propose alternative modes of receptor activation acting synergistically in the mature liganded receptor complex.
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- 2010
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39. Expression profiling of a hemopoietic cell survival transcriptome implicates osteopontin as a functional prognostic factor in AML
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Powell, Jason A., Thomas, Daniel, Barry, Emma F., Kok, Chung H., McClure, Barbara J., Tsykin, Anna, To, L. Bik, Brown, Anna, Lewis, Ian D., Herbert, Kirsten, Goodall, Gregory J., Speed, Terence P., Asou, Norio, Jacob, Bindya, Osato, Motomi, Haylock, David N., Nilsson, Susan K., D'Andrea, Richard J., Lopez, Angel F., and Guthridge, Mark A.
- Abstract
Deregulated cell survival programs are a classic hallmark of cancer. We have previously identified a serine residue (Ser585) in the βc subunit of the granulocyte-macrophage colony-stimulating factor receptor that selectively and independently promotes cell survival. We now show that Ser585 phosphorylation is constitutive in 20 (87%) of 23 acute myeloid leukemia (AML) patient samples, indicating that this survival-only pathway is frequently deregulated in leukemia. We performed a global expression screen to identify gene targets of this survival pathway and report a 138-gene βc Ser585-regulated transcriptome. Pathway analysis defines a gene network enriched for PI3-kinase target genes and a cluster of genes involved in cancer and cell survival. We show that one such gene, osteopontin (OPN), is a functionally relevant target of the Ser585-survival pathway as shown by siRNA-mediated knockdown of OPN expression that induces cell death in both AML blasts and CD34+CD38−CD123+ leukemic progenitors. Increased expression of OPN at diagnosis is associated with poor prognosis with multivariate analysis indicating that it is an independent predictor of overall patient survival in normal karyotype AML (n = 60; HR = 2.2; P = .01). These results delineate a novel cytokine-regulated Ser585/PI3-kinase signaling network that is deregulated in AML and identify OPN as a potential prognostic and therapeutic target.
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- 2009
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40. The granulocyte-macrophage colony-stimulating factor receptor: linking its structure to cell signaling and its role in disease
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Hercus, Timothy R., Thomas, Daniel, Guthridge, Mark A., Ekert, Paul G., King-Scott, Jack, Parker, Michael W., and Lopez, Angel F.
- Abstract
Already 20 years have passed since the cloning of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor α-chain, the first member of the GM-CSF/interleukin (IL)–3/IL-5 family of hemopoietic cytokine receptors to be molecularly characterized. The intervening 2 decades have uncovered a plethora of biologic functions transduced by the GM-CSF receptor (pleiotropy) and revealed distinct signaling networks that couple the receptor to biologic outcomes. Unlike other hemopoietin receptors, the GM-CSF receptor has a significant nonredundant role in myeloid hematologic malignancies, macrophage-mediated acute and chronic inflammation, pulmonary homeostasis, and allergic disease. The molecular mechanisms underlying GM-CSF receptor activation have recently been revealed by the crystal structure of the GM-CSF receptor complexed to GM-CSF, which shows an unexpected higher order assembly. Emerging evidence also suggests the existence of intracellular signosomes that are recruited in a concentration-dependent fashion to selectively control cell survival, proliferation, and differentiation by GM-CSF. These findings begin to unravel the mystery of cytokine receptor pleiotropy and are likely to also apply to the related IL-3 and IL-5 receptors as well as other heterodimeric cytokine receptors. The new insights in GM-CSF receptor activation have clinical significance as the structural and signaling nuances can be harnessed for the development of new treatments for malignant and inflammatory diseases.
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- 2009
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41. Sphingosine kinase regulates the rate of endothelial progenitor cell differentiation
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Bonder, Claudine S., Sun, Wai Y., Matthews, Tyson, Cassano, Carlos, Li, Xiaochun, Ramshaw, Hayley S., Pitson, Stuart M., Lopez, Angel F., Coates, P. Toby, Proia, Richard L., Vadas, Mathew A., and Gamble, Jennifer R.
- Abstract
Circulating endothelial progenitor cells (EPCs) are incorporated into foci of neovascularization where they undergo differentiation to mature endothelial cells (ECs). We show here that the enzyme sphingosine kinase-1 (SK-1) regulates the rate and direction of EPC differentiation without effect on the hematopoietic compartment. EPCs have high levels of SK-1 activity, which diminishes with differentiation and is, at least partially, responsible for maintaining their EPC phenotype. EPCs from SK-1 knockout mice form more adherent EC units and acquire a mature EC phenotype more rapidly. Conversely, EPCs from mice overexpressing SK-1 in the EC compartment are retarded in their differentiation. Exogenous regulation of SK-1 levels in normal EPCs, by genetic and pharmacologic means, including the immunomodulating drug FTY720, recapitulates these effects on EC differentiation. SK-1 knockout mice have higher levels of circulating EPCs, an exaggerated response to erythropoietin-induced EPC mobilization, and, in a mouse model of kidney ischemia reperfusion injury, exhibit a recovery similar to that of ischemic mice administered exogenous EPCs. Thus, SK-1 is a critical player in EPC differentiation into EC pointing to the potential utility of SK-1 modifying agents in the specific manipulation of endothelial development and repair.
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- 2009
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42. A functional 14-3-3ζ–independent association of PI3-kinase with glycoprotein Ibα, the major ligand-binding subunit of the platelet glycoprotein Ib-IX-V complex
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Mu, Fi-Tjen, Andrews, Robert K., Arthur, Jane F., Munday, Adam D., Cranmer, Susan L., Jackson, Shaun P., Stomski, Frank C., Lopez, Angel F., and Berndt, Michael C.
- Abstract
Engagement of the adhesion receptor glycoprotein (GP) Ib-IX-V by von Willebrand factor (VWF) mediates platelet adhesion to damaged vessels and triggers platelet activation and thrombus formation in heart attack and stroke. GPIb-IX-V contains distinct 14-3-3ζ–binding sites at the GPIbα C-terminus involving phosphorylation of Ser609, an upstream site involving phosphorylated Ser587/Ser590, and a protein kinase A (PKA)–dependent site on GPIbβ involving Ser166. 14-3-3ζ regulates the VWF-binding affinity of GPIb-IX-V and inhibiting 14-3-3ζ association blocks receptor signaling, suggesting a key functional role for 14-3-3ζ. We used deletion mutants of GPIbα expressed in Chinese hamster ovary (CHO) cells to define the relationship of 14-3-3ζ binding to another GPIb-IX-V–associated signaling protein, phosphoinositide 3-kinase (PI3-kinase). Pull-down experiments involving glutathione S-transferase (GST)–PI3-kinase/p85-subunit and GST–14-3-3ζ indicated that both proteins interacted with contiguous GPIbα sequences 580 to 590/591 to 610. Deleting these, but not upstream sequences of GPIbα expressed in CHO cells, inhibited VWF/ristocetin-dependent Akt phosphorylation, relative to wild-type receptor, confirming this region encompassed a functional PI3-kinase–binding site. Pull-down experiments with GST-p85 truncates indicated the GPIbα-binding region involved the p85 breakpoint cluster region (BCR) domain, containing RSXSXP. However, pull-down of GPIb-IX was unaltered by mutation/deletion/phosphorylation of this potential 14-3-3ζ–binding sequence in mutant constructs of GST-p85, suggesting PI3-kinase bound GPIbα independently of 14-3-3ζ; 14-3-3ζ inhibitor peptide R18 also blocked pull-down of receptor by GST-14-3-3ζ but not GST-p85, and GST-p85 pull-downs were unaffected by excess 14-3-3ζ. Together, these data suggest the GPIbα C-terminus regulates signaling through independent association of 14-3-3ζ and PI3-kinase.
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- 2008
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43. The Shc-binding site of the βc subunit of the GM-CSF/IL-3/IL-5 receptors is a negative regulator of hematopoiesis
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Ramshaw, Hayley S., Guthridge, Mark A., Stomski, Frank C., Barry, Emma F., Ooms, Lisa, Mitchell, Christina A., Begley, C. Glenn, and Lopez, Angel F.
- Abstract
Tyrosine and serine phosphorylation of the common β chain (βc) of the granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 receptors is widely viewed as a general mechanism that provides positive inputs by coupling the receptor to signaling pathways that stimulate several cellular functions. We show here that despite the known action of Tyr577 in βc to recruit Shc–PI-3 kinase (PI3K) pathway members, Tyr577 plays, surprisingly, a negative regulatory role in cell function, and that this is mediated, at least in part, through the uncoupling of SH2-containing inositol 5′-phosphatase (SHIP) from βc. Fetal liver cells from βc/βIL-3−/− mice expressing human GM-CSF receptor α chain and βc Tyr577Phe mutant showed enhanced colony formation and expansion of progenitor cells in response to GM-CSF. Dissection of these activities revealed that basal survival was increased, as well as cytokine-stimulated proliferation. As expected, the recruitment and activation of Shc was abolished, but interestingly, Gab-2 and Akt phosphorylation increased. Significantly, the activation of PI3K was enhanced and prolonged, accompanied by loss of SHIP activity. These results reveal a previously unrecognized negative signaling role for Tyr577 in βc and demonstrate that uncoupling Shc from cytokine receptors enhances PI3K signaling as well as survival and proliferation.
- Published
- 2007
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44. The Shc-binding site of the βcsubunit of the GM-CSF/IL-3/IL-5 receptors is a negative regulator of hematopoiesis
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Ramshaw, Hayley S., Guthridge, Mark A., Stomski, Frank C., Barry, Emma F., Ooms, Lisa, Mitchell, Christina A., Begley, C. Glenn, and Lopez, Angel F.
- Abstract
Tyrosine and serine phosphorylation of the common β chain (βc) of the granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 receptors is widely viewed as a general mechanism that provides positive inputs by coupling the receptor to signaling pathways that stimulate several cellular functions. We show here that despite the known action of Tyr577 in βcto recruit Shc–PI-3 kinase (PI3K) pathway members, Tyr577 plays, surprisingly, a negative regulatory role in cell function, and that this is mediated, at least in part, through the uncoupling of SH2-containing inositol 5′-phosphatase (SHIP) from βc. Fetal liver cells from βc/βIL-3−/−mice expressing human GM-CSF receptor α chain and βcTyr577Phe mutant showed enhanced colony formation and expansion of progenitor cells in response to GM-CSF. Dissection of these activities revealed that basal survival was increased, as well as cytokine-stimulated proliferation. As expected, the recruitment and activation of Shc was abolished, but interestingly, Gab-2 and Akt phosphorylation increased. Significantly, the activation of PI3K was enhanced and prolonged, accompanied by loss of SHIP activity. These results reveal a previously unrecognized negative signaling role for Tyr577 in βcand demonstrate that uncoupling Shc from cytokine receptors enhances PI3K signaling as well as survival and proliferation.
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- 2007
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45. The Localized Chemical Pollution in NGC 5253 Revisited: Results from Deep Echelle Spectrophotometry
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Lopez, Angel R., Esteban, Cesar, Garcia, Jorge, Peimbert, Manuel, and Rodriguez, Monica
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We present echelle spectrophotometry of the blue compact dwarf galaxy NGC 5253 obtained with the VLT UVES. We have measured the intensities of a large number of permitted and forbidden emission lines in four zones of the central part of the galaxy. We detect faint C II and O II recombination lines, the first time that these are unambiguously detected in a dwarf starburst galaxy. The physical conditions of the ionized gas have been derived using a large number of different line intensity ratios. Chemical abundances of He, N, O, Ne, S, Cl, Ar, and Fe have been determined following standard methods. C++ and O++ abundances have been derived from pure recombination lines and are larger than those obtained from collisionally excited lines (from 0.30 to 0.40 dex for C++ and from 0.19 to 0.28 dex for O++). This result is consistent with a temperature fluctuation parameter (t2) between 0.050 and 0.072. We confirm previous results that indicate the presence of a localized N enrichment in certain zones of NGC 5253 and detect a possible slight He overabundance in the same zones. The enrichment pattern agrees with that expected for the pollution by the ejecta of Wolf-Rayet (W-R) stars. The amount of enriched material needed to produce the observed overabundance is consistent with the mass lost by the number of W-R stars estimated in the starbursts. We discuss the possible origin of the difference between abundances derived from recombination and collisionally excited lines (the so-called abundance discrepancy problem) in H II regions, finding that a recent hypothesis based on the delayed enrichment by SN ejecta inclusions seems not to explain the observed features.
- Published
- 2007
46. The Bent Dick Squad.
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Lopez, Angel Dean
- Abstract
Presents the author's views on writing the script for the pilot episode of the unproduced television drama "The Bent Dick Squad." Role of a psychotherapist in the development of the script; Research done for the script; Overview of the plot and the script of the drama.
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- 2006
47. Regulation of haematopoiesis by growth factors – emerging insights and therapies
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Thomas, Daniel, Vadas, Mathew, and Lopez, Angel
- Abstract
Haematopoiesis is regulated by a wide variety of glycoprotein hormones, including stem cell factor, granulocyte-macrophage colony-stimulating factor, thrombopoietin and IL-3. These haematopoietic growth factors (HGFs) share a number of properties, including redundancy, pleiotropy, autocrine and paracrine effects, receptor subunit oligomerisation and similar signal transduction mechanisms, yet each one has a unique spectrum of haematopoietic activity. Ongoing studies with knockout mice have discovered previously unrecognised physiological roles for HGFs, linking haematopoiesis to innate immunity, pulmonary physiology and bone metabolism. The regulation of stem cells by HGFs within niches of the bone marrow microenvironment is now well recognised and similar mechanisms appear to exist in the regulation of other stem cell compartments. Alternative signalling strategies, other than tyrosine kinase activation and phosphotyrosine cascades, may account for some of the more subtle differences between HGFs. Accumulating evidence suggests that some, but not all, HGF receptors can transduce a genuine lineage-determining signal at certain points in haematopoiesis. Further studies, primarily at the receptor level, are needed to determine the mechanisms of instructive signalling, which may include phosphoserine cascades. Novel haematopoietic regulators, as well as the development of biological therapies, including growth factor antagonists and peptide mimetics, are also discussed.
- Published
- 2004
- Full Text
- View/download PDF
48. The phosphoserine-585–dependent pathway of the GM-CSF/IL-3/IL-5 receptors mediates hematopoietic cell survival through activation of NF-κB and induction of bcl-2
- Author
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Guthridge, Mark A., Barry, Emma F., Felquer, Fernando A., McClure, Barbara J., Stomski, Frank C., Ramshaw, Hayley, and Lopez, Angel F.
- Abstract
We have recently identified a novel mechanism of hematopoietic cell survival that involves site-specific serine phosphorylation of the common beta subunit (βc) of the granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 receptors. However, the downstream components of this pathway are not known, nor is its relationship to survival signals triggered by tyrosine phosphorylation of the receptor clear. We have now found that phosphorylation of Ser585 of βc in response to GM-CSF recruited 14-3-3 and phosphatidyl inositol 3-OH kinase (PI 3-kinase) to the receptor, while phosphorylation of the neighboring Tyr577 within this “viability domain” promoted the activation of both Src homology and collagen (Shc) and Ras. These are independent processes as demonstrated by the intact reactivity of phosphospecific anti-Ser585 and anti-Tyr577 antibodies on the cytotoxic T-lymphocyte–ecotrophic retroviral receptor neomycin (CTL-EN) mutants βcTyr577Phe and βcSer585Gly, respectively. Importantly, while mutants in which either Ser585 (βcSer585Gly) or all tyrosines (βcF8) were substituted showed a defect in Akt phosphorylation, nuclear factor κB (NF-κB) activation, bcl-2 induction, and cell survival, the mutant βcTyr577Phe was defective in Shc, Ras, and extracellular signal-related kinase (ERK) activation, but supported CTL-EN cell survival in response to GM-CSF. These results demonstrate that both serine and tyrosine phosphorylation pathways play a role in hematopoietic cell survival, are initially independent of each other, and converge on NF-κB to promote bcl-2 expression.
- Published
- 2004
- Full Text
- View/download PDF
49. Molecular assembly of the ternary granulocyte-macrophage colony-stimulating factor receptor complex
- Author
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McClure, Barbara J., Hercus, Timothy R., Cambareri, Bronwyn A., Woodcock, Joanna M., Bagley, Christopher J., Howlett, Geoff J., and Lopez, Angel F.
- Abstract
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic cytokine that stimulates the production and functional activity of granulocytes and macrophages, properties that have encouraged its clinical use in bone marrow transplantation and in certain infectious diseases. Despite the importance of GM-CSF in regulating myeloid cell numbers and function, little is known about the exact composition and mechanism of assembly of the GM-CSF receptor complex. We have now produced soluble forms of the GM-CSF receptor α chain (sGMRα) and β chain (sβc) and utilized GM-CSF, the GM-CSF antagonist E21R (Glu21Arg), and the βc-blocking monoclonal antibody BION-1 to define the molecular assembly of the GM-CSF receptor complex. We found that GM-CSF and E21R were able to form low-affinity, binary complexes with sGMRα, each having a stoichiometry of 1:1. Importantly, GM-CSF but not E21R formed a ternary complex with sGMRα and sβc, and this complex could be disrupted by E21R. Significantly, size-exclusion chromatography, analytical ultracentrifugation, and radioactive tracer experiments indicated that the ternary complex is composed of one sβc dimer with a single molecule each of sGMRα and of GM-CSF. In addition, a hitherto unrecognized direct interaction between βc and GM-CSF was detected that was absent with E21R and was abolished by BION-1. These results demonstrate a novel mechanism of cytokine receptor assembly likely to apply also to interleukin-3 (IL-3) and IL-5 and have implications for our molecular understanding and potential manipulation of GM-CSF activation of its receptor.
- Published
- 2003
- Full Text
- View/download PDF
50. Perverted responses of the human granulocyte-macrophage colony-stimulating factor receptor in mouse cell lines due to cross-species β-subunit association
- Author
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McClure, Barbara, Stomski, Frank, Lopez, Angel, and Woodcock, Joanna
- Abstract
Transfected murine cell lines are commonly used to study the function of many human cytokine or receptor mutants. This study reports the inappropriate activation of the human granulocyte-macrophage colony-stimulating factor (hGM-CSF) receptor by the human GM-CSF antagonist, E21R, when the human receptor is introduced into the murine cell line BaF-B03. E21R-induced proliferation of the BaF-B03 cells is dependent on transfection with both hGM-CSF receptor α and βc subunits. Studies on the underlying mechanism revealed constitutive association between human and mouse βc and GM-CSF receptor-α, tyrosine phosphorylation of mouse and human βc, and association of phosphorylated mouse βc into an activated human GM-CSF receptor complex in response to E21R and GM-CSF. This interspecies receptor cross-talk of receptor signaling subunits may produce misleading results and emphasizes the need to use cell lines devoid of the cognate endogenous receptors for functional analysis of ligand and receptor mutants.
- Published
- 2001
- Full Text
- View/download PDF
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