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Jones CT, Meynell L, Neto C, Susko E, Bielawski JP. The role of the ecological scaffold in the origin and maintenance of whole-group trait altruism in microbial populations. BMC Ecol Evol 2023; 23:11. [PMID: 37046187 PMCID: PMC10100367 DOI: 10.1186/s12862-023-02112-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 03/24/2023] [Indexed: 04/14/2023] Open
Abstract
BACKGROUND Kin and multilevel selection provide explanations for the existence of altruism based on traits or processes that enhance the inclusive fitness of an altruist individual. Kin selection is often based on individual-level traits, such as the ability to recognize other altruists, whereas multilevel selection requires a metapopulation structure and dispersal process. These theories are unified by the general principle that altruism can be fixed by positive selection provided the benefit of altruism is preferentially conferred to other altruists. Here we take a different explanatory approach based on the recently proposed concept of an "ecological scaffold". We demonstrate that ecological conditions consisting of a patchy nutrient supply that generates a metapopulation structure, episodic mixing of groups, and severe nutrient limitation, can support or "scaffold" the evolution of altruism in a population of microbes by amplifying drift. This contrasts with recent papers in which the ecological scaffold was shown to support selective processes and demonstrates the power of scaffolding even in the absence of selection. RESULTS Using computer simulations motivated by a simple theoretical model, we show that, although an altruistic mutant can be fixed within a single population of non-altruists by drift when nutrients are severely limited, the resulting altruistic population remains vulnerable to non-altruistic mutants. We then show how the imposition of the "ecological scaffold" onto a population of non-altruists alters the balance between selection and drift in a way that supports the fixation and subsequent persistence of altruism despite the possibility of invasion by non-altruists. CONCLUSIONS The fixation of an altruistic mutant by drift is possible when supported by ecological conditions that impose a metapopulation structure, episodic mixing of groups, and severe nutrient limitation. This is significant because it offers an alternative explanation for the evolution of altruism based on drift rather than selection. Given the ubiquity of low-nutrient "oligotrophic" environments in which microbes exist (e.g., the open ocean, deep subsurface soils, or under the polar ice caps) our results suggest that altruistic and cooperative behaviors may be highly prevalent among microbial populations.
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Affiliation(s)
- C T Jones
- Department of Biochemistry and Molecular Biology, Dalhousie University, NS, Halifax, Canada.
| | - L Meynell
- Department of Philosophy, Dalhousie University, Halifax, Canada
| | - C Neto
- Department of Social and Political Sciences, Philosophy, and Anthropology, University of Exeter, Exeter, UK
- Centre for the Study of the Life Sciences, EGENIS, University of Exeter, Exeter, UK
| | - E Susko
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Canada
| | - J P Bielawski
- Department of Biology and Dept. of Mathematics and Statistics, Dalhousie University, Halifax, Canada
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2
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Jones CT, Youssef N, Susko E, Bielawski JP. A Phenotype-Genotype Codon Model for Detecting Adaptive Evolution. Syst Biol 2021; 69:722-738. [PMID: 31730199 DOI: 10.1093/sysbio/syz075] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 11/09/2019] [Accepted: 11/11/2019] [Indexed: 01/03/2023] Open
Abstract
A central objective in biology is to link adaptive evolution in a gene to structural and/or functional phenotypic novelties. Yet most analytic methods make inferences mainly from either phenotypic data or genetic data alone. A small number of models have been developed to infer correlations between the rate of molecular evolution and changes in a discrete or continuous life history trait. But such correlations are not necessarily evidence of adaptation. Here, we present a novel approach called the phenotype-genotype branch-site model (PG-BSM) designed to detect evidence of adaptive codon evolution associated with discrete-state phenotype evolution. An episode of adaptation is inferred under standard codon substitution models when there is evidence of positive selection in the form of an elevation in the nonsynonymous-to-synonymous rate ratio $\omega$ to a value $\omega > 1$. As it is becoming increasingly clear that $\omega > 1$ can occur without adaptation, the PG-BSM was formulated to infer an instance of adaptive evolution without appealing to evidence of positive selection. The null model makes use of a covarion-like component to account for general heterotachy (i.e., random changes in the evolutionary rate at a site over time). The alternative model employs samples of the phenotypic evolutionary history to test for phenomenological patterns of heterotachy consistent with specific mechanisms of molecular adaptation. These include 1) a persistent increase/decrease in $\omega$ at a site following a change in phenotype (the pattern) consistent with an increase/decrease in the functional importance of the site (the mechanism); and 2) a transient increase in $\omega$ at a site along a branch over which the phenotype changed (the pattern) consistent with a change in the site's optimal amino acid (the mechanism). Rejection of the null is followed by post hoc analyses to identify sites with strongest evidence for adaptation in association with changes in the phenotype as well as the most likely evolutionary history of the phenotype. Simulation studies based on a novel method for generating mechanistically realistic signatures of molecular adaptation show that the PG-BSM has good statistical properties. Analyses of real alignments show that site patterns identified post hoc are consistent with the specific mechanisms of adaptation included in the alternate model. Further simulation studies show that the covarion-like component of the PG-BSM plays a crucial role in mitigating recently discovered statistical pathologies associated with confounding by accounting for heterotachy-by-any-cause. [Adaptive evolution; branch-site model; confounding; mutation-selection; phenotype-genotype.].
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Affiliation(s)
- Christopher T Jones
- Department of Mathematics and Statistics, Dalhousie University, 1233 LeMarchant Street, B3H 4R2, Halifax, Nova Scotia, Canada
| | - Noor Youssef
- Department of Biology, Dalhousie University, 1233 LeMarchant Street, B3H 4R2, Halifax, Nova Scotia, Canada
| | - Edward Susko
- Department of Mathematics and Statistics, Dalhousie University, 1233 LeMarchant Street, B3H 4R2, Halifax, Nova Scotia, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, 1233 LeMarchant Street, B3H 4R2, Halifax, Nova Scotia, Canada
| | - Joseph P Bielawski
- Department of Mathematics and Statistics, Dalhousie University, 1233 LeMarchant Street, B3H 4R2, Halifax, Nova Scotia, Canada.,Department of Biology, Dalhousie University, 1233 LeMarchant Street, B3H 4R2, Halifax, Nova Scotia, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, 1233 LeMarchant Street, B3H 4R2, Halifax, Nova Scotia, Canada
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3
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Mecholsky JJ, Barrett AA, Jones CT, Pace KM, Nair UP. Fractographic analysis of separated endodontic file designs. J Mater Sci Mater Med 2020; 31:104. [PMID: 33140130 DOI: 10.1007/s10856-020-06432-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 09/24/2020] [Indexed: 06/11/2023]
Abstract
Endodontic rotary files are cutting instruments used to perform root canal procedures within a tooth interior. Focusing on quantitative fractographic analysis increases necessary, clinical performance understanding of file separation failure. This research employed controlled, dynamic testing to failure of commercial rotary files, analyzing the fractographic, forensic characteristics in relation to Weibull reliability determination, considering: (1) design analysis; (2) stress concentrations; (3) times to failure; (4) number of cycles to failure (NCF). Ex vivo testing included three file designs, each having constant tip size (0.035 mm), taper (0.06 mm/mm), and length (25 mm). Files were individually tested using an electric, torque-controlled handpiece, rotating within a standardized, simulated canal until fracture separation occurred. Fractographic analysis, including critical measurements, was conducted using the scanning electron microscope (SEM) (PhenomProX, PhenomWorld, NL). Weibull statistical analysis established reliability factors per design group. Fractographic analysis identified separation fractures, processing inclusions, flexural-fatigue striations, and stress concentrations at flute pitches. Calculated NCF median values (1277-EE; 899-VB; 713-PI) demonstrated significant statistical differences among groups (p < 0.001). Separated apical fragments yielded statistically significant differences (p ≤ 0.05) for varying file design groups. Weibull moduli among groups were statistically equivalent. Fractographic analysis exposed a presence of multiple failure factors in addition to defect distribution, governing cyclic fatigue failure originating at stress concentration points irrespective of file design. Fractographic analysis indicated that a change in file design, specifically at the working edges, in addition to improved surface finish, has the potential of reducing failures by lowering points of stress concentration and reducing fracture initiating surface cracks.
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Affiliation(s)
- J J Mecholsky
- Department of Materials Science & Engineering, Center for Dental Biomaterials, College of Engineering, University of Florida, Gainesville, FL, 32611-6400, USA.
- Center for Dental Biomaterials, Department of Materials Science & Engineering, College of Engineering, University of Florida, Gainesville, FL, 32611-6400, USA.
| | - A A Barrett
- Center for Dental Biomaterials, Department of Materials Science & Engineering, College of Engineering, University of Florida, Gainesville, FL, 32611-6400, USA
| | - C T Jones
- Department of Endodontics, College of Dentistry, University of Florida, Gainesville, FL, 32611-6400, USA
- Practice Limited to Endodontics, Melbourne, FL, USA
| | - K M Pace
- Department of Materials Science & Engineering, College of Engineering, University of Florida, Gainesville, FL, 32611-6400, USA
- Alight Solutions, Dallas, TX, USA
| | - U P Nair
- Practice Limited to Endodontics, Dallas, TX, USA
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Kirschberg TA, Jones CT, Xu Y, Fenaux M, Halcomb RL, Wang Y, Klucher K. Selective thyroid hormone receptor β agonists with oxadiazolone acid isosteres. Bioorg Med Chem Lett 2020; 30:127465. [PMID: 32768645 DOI: 10.1016/j.bmcl.2020.127465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/26/2020] [Accepted: 08/02/2020] [Indexed: 12/14/2022]
Abstract
Use of the oxadiazolone acid isostere in triiodothyronine analogs yielded potent and selective agonists for the thyroid hormone receptor β. Selected examples showed good in-vivo efficacy in a rat hypercholesterolemic model. One compound was further profiled in a diet-induced mouse model of nonalcoholic steatohepatitis (NASH) and showed robust target engagement and significant histological improvements in both liver steatosis and fibrosis.
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Affiliation(s)
- Thorsten A Kirschberg
- Terns Pharmaceuticals Inc., 1065 E. Hillsdale Blvd., Suite 100, Foster City, CA 94404, USA.
| | - Christopher T Jones
- Terns Pharmaceuticals Inc., 1065 E. Hillsdale Blvd., Suite 100, Foster City, CA 94404, USA
| | - Yingzi Xu
- Terns Pharmaceuticals Inc., 1065 E. Hillsdale Blvd., Suite 100, Foster City, CA 94404, USA
| | - Martijn Fenaux
- Terns Pharmaceuticals Inc., 1065 E. Hillsdale Blvd., Suite 100, Foster City, CA 94404, USA
| | - Randall L Halcomb
- Terns Pharmaceuticals Inc., 1065 E. Hillsdale Blvd., Suite 100, Foster City, CA 94404, USA
| | - Yujin Wang
- Terns Pharmaceuticals Inc., 1065 E. Hillsdale Blvd., Suite 100, Foster City, CA 94404, USA
| | - Kevin Klucher
- Terns Pharmaceuticals Inc., 1065 E. Hillsdale Blvd., Suite 100, Foster City, CA 94404, USA
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5
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Abstract
Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease (NAFLD) characterized by liver steatosis, inflammation, and hepatocellular damage. NASH is a serious condition that can progress to cirrhosis, liver failure, and hepatocellular carcinoma. The association of NASH with obesity, type 2 diabetes mellitus, and dyslipidemia has led to an emerging picture of NASH as the liver manifestation of metabolic syndrome. Although diet and exercise can dramatically improve NASH outcomes, significant lifestyle changes can be challenging to sustain. Pharmaceutical therapies could be an important addition to care, but currently none are approved for NASH. Here, we review the most promising targets for NASH treatment, along with the most advanced therapeutics in development. These include targets involved in metabolism (e.g., sugar, lipid, and cholesterol metabolism), inflammation, and fibrosis. Ultimately, combination therapies addressing multiple aspects of NASH pathogenesis are expected to provide benefit for patients.
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Affiliation(s)
- F Anthony Romero
- Terns Pharmaceuticals, 1065 E. Hillsdale Blvd., Suite 100, Foster City, California 94404, United States
| | - Christopher T Jones
- Terns Pharmaceuticals, 1065 E. Hillsdale Blvd., Suite 100, Foster City, California 94404, United States
| | - Yingzi Xu
- Terns Pharmaceuticals, 1065 E. Hillsdale Blvd., Suite 100, Foster City, California 94404, United States
| | - Martijn Fenaux
- Terns Pharmaceuticals, 1065 E. Hillsdale Blvd., Suite 100, Foster City, California 94404, United States
| | - Randall L Halcomb
- Terns Pharmaceuticals, 1065 E. Hillsdale Blvd., Suite 100, Foster City, California 94404, United States
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Jones CT, Youssef N, Susko E, Bielawski JP. Phenomenological Load on Model Parameters Can Lead to False Biological Conclusions. Mol Biol Evol 2019; 35:1473-1488. [PMID: 29596684 DOI: 10.1093/molbev/msy049] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
When a substitution model is fitted to an alignment using maximum likelihood, its parameters are adjusted to account for as much site-pattern variation as possible. A parameter might therefore absorb a substantial quantity of the total variance in an alignment (or more formally, bring about a substantial reduction in the deviance of the fitted model) even if the process it represents played no role in the generation of the data. When this occurs, we say that the parameter estimate carries phenomenological load (PL). Large PL in a parameter estimate is a concern because it not only invalidates its mechanistic interpretation (if it has one) but also increases the likelihood that it will be found to be statistically significant. The problem of PL was not identified in the past because most off-the-shelf substitution models make simplifying assumptions that preclude the generation of realistic levels of variation. In this study, we use the more realistic mutation-selection framework as the basis of a generating model formulated to produce data that mimic an alignment of mammalian mitochondrial DNA. We show that a parameter estimate can carry PL when 1) the substitution model is underspecified and 2) the parameter represents a process that is confounded with other processes represented in the data-generating model. We then provide a method that can be used to identify signal for the process that a given parameter represents despite the existence of PL.
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Affiliation(s)
- Christopher T Jones
- Department of Mathematics and Statistics, Dalhousie University, Halifax, NS, Canada
| | - Noor Youssef
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Edward Susko
- Department of Mathematics and Statistics, Dalhousie University, Halifax, NS, Canada
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Youngberg S, Brandt E, Barve A, Machineni S, Jones CT, Dabovic K, Jones CL, Colvin RA. A first-in-human, randomized, double-blind, placebo-controlled, single and multiple ascending oral dose study to assess the safety, tolerability, and pharmacokinetics of BZF961 with and without ritonavir in healthy adult volunteers. J Drug Assess 2018; 7:66-74. [PMID: 30370176 PMCID: PMC6201795 DOI: 10.1080/21556660.2018.1535438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/09/2018] [Indexed: 11/01/2022] Open
Abstract
Objective: Infection with hepatitis C virus is the leading indication for liver transplantation and most common cause of infectious disease-related mortality in the United States. BZF961 is a novel inhibitor of the hepatitis C virus NS3-4A protease. Methods: This sequential, three part exploratory first-in-human study investigated the safety and pharmacokinetics of single and multiple ascending oral doses of BZF961 in healthy subjects. The first two parts were randomized, double-blind, placebo-controlled, time-lagged, single and multiple ascending oral dose segments. The third part analyzed the effect of ritonavir on BZF961 pharmacokinetics. Results: BZF961 was generally safe and well-tolerated in single and multiple oral doses in healthy subjects. There were no deaths and no serious adverse events. The most common adverse events were nausea and other gastrointestinal symptoms. Co-administration of ritonavir with BZF961 was well tolerated and increased BZF961 exposure by up to 60-fold, as well as reduced the overall exposure variability. Conclusions: BZF961 was generally safe and well-tolerated and its exposure was boosted by the co-administration of ritonavir.
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Affiliation(s)
| | | | - Avantika Barve
- Novartis Institutes for BioMedical Research, East Hanover, NJ, USA
| | | | | | - Kristina Dabovic
- Novartis Institutes for BioMedical Research, East Hanover, NJ, USA
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8
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Lawitz E, Bidair M, Marbury T, Jones CT, Barve A, Magnusson B, Barkan DT, Bodendorf U, Bracken K, Canino E, Chen D, Dabovic K, Heimbach T, Ison M, Jones CL, Kovacs SJ, Lakshman JP, Li B, Raman P, Steiner-Swiat R, Thohan S, Wong KA, Zhong W, Colvin RA. The Safety and Antiviral Activity of BZF961 with or without Ritonavir in Patients Infected with Hepatitis C Virus: A Randomized, Multicenter Trial. Clin Ther 2018; 40:1567-1581.e4. [PMID: 30185394 DOI: 10.1016/j.clinthera.2018.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE Infection with hepatitis C virus is the leading cause of infectious disease mortality in the United States. BZF961 is a novel small molecule inhibitor of the hepatitis C virus NS3-4A protease. Here we present the results of a randomized, double-blinded, placebo-controlled, multicentered study in treatment-naïve patients with chronic hepatitis C virus genotype-1 infection. METHODS Patients were enrolled sequentially in 2 parts and treated for 3days. BZF961 was administered as monotherapy (500mg BID for 3 days) or in combination with the cytochrome P450 3A4 inhibitor ritonavir to boost its exposure (BZF961 10, 20, or 50mg QD or BID). FINDINGS BZF961 was safe and well tolerated in the patients studied with no serious adverse events. There were no appreciable differences in adverse events among patients who received BZF961, BZF961 with ritonavir, or placebo. There was a significant, clinically meaningful reduction in viral load from baseline in patients treated either with BZF961 500mg every 12hours alone or BZF961 50mg every 12hours in combination with ritonavir. Activity against the hepatitis C virus of the lower-dose regimens was apparent but more modest. There were no relevant changes from baseline viral loads in placebo-treated patients. IMPLICATIONS Coadministration of ritonavir with BZF961 boosted BZF961 exposure (including Cmin, which is the clinically relevant parameter associated with antiviral activity) in a therapeutic range with less variability compared with BZF961 alone. For strategic reasons, BZF961 is no longer under development.
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Affiliation(s)
- Eric Lawitz
- Texas Liver Institute, University of Texas Health San Antonio, San Antonio, Texas
| | | | | | | | | | | | - David T Barkan
- Novartis Institutes for BioMedical Research, Emeryville, California
| | | | - Kathryn Bracken
- Novartis Institute for BioMedical Research, Cambridge, Massachusetts
| | - Erica Canino
- Novartis Institutes for BioMedical Research, Emeryville, California
| | - Darlene Chen
- Novartis Institutes for BioMedical Research, Emeryville, California
| | | | | | - Marjorie Ison
- Novartis Institutes for BioMedical Research, Emeryville, California
| | | | - Steven J Kovacs
- Novartis Institute for BioMedical Research, Cambridge, Massachusetts
| | | | - Bin Li
- Novartis Institute for BioMedical Research, Cambridge, Massachusetts
| | | | | | - Sanjeev Thohan
- Novartis Institute for BioMedical Research, Cambridge, Massachusetts
| | - Kelly A Wong
- Novartis Institutes for BioMedical Research, Emeryville, California
| | - Weidong Zhong
- Novartis Institutes for BioMedical Research, Emeryville, California
| | - Richard A Colvin
- Novartis Institute for BioMedical Research, Cambridge, Massachusetts.
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Jones CT, Chen CY, Campbell BG, Fransson BA. Assessment of leakage pressure following enterotomy closure reinforced by tissue adhesive in a caprine cadaver model. N Z Vet J 2017. [DOI: 10.1080/00480169.2017.1344586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- CT Jones
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6610, USA
| | - CY Chen
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6610, USA
- Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, Canada C1A 4P3
| | - BG Campbell
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6610, USA
| | - BA Fransson
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6610, USA
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Jones CT, Youssef N, Susko E, Bielawski JP. Shifting Balance on a Static Mutation-Selection Landscape: A Novel Scenario of Positive Selection. Mol Biol Evol 2017; 34:391-407. [PMID: 28110273 DOI: 10.1093/molbev/msw237] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A version of the mechanistic mutation-selection (MutSel) model that accounts for temporal dynamics at a site is presented. This is used to show that the rate ratio dN/dS at a site can be transiently >1 even when fitness coefficients are fixed or the fitness landscape is static. This occurs whenever a site drifts away from its fitness peak and is then forced back by selection, a process reminiscent of shifting balance. Shifting balance is strongest when the substitution process is not dominated by selection or drift, but admits interplay between the two. Under this condition, site-specific changes in dN/dS were inferred in 78-100% of trials, and positive selection (i.e., dN/dS>1) in 10-40% of trials, when sequence alignments generated under MutSel were fitted to two popular phenomenological branch-site models. These results demonstrate that positive selection can occur without a change in fitness regime, and that this is detectable by branch-site models. In addition, MutSel is used to show that a site can be occupied by a sub-optimal amino acid for long periods on a fixed landscape when selection is stringent. This has implications for the interpretation of constant-but-different site patterns typically attributed to changes in fitness. Furthermore, a version of MutSel with episodic changes in fitness coefficients is used to illustrate systematic differences between parameters used to generate data under MutSel and their counterparts estimated by a simple codon model. Motivated by a discrepancy in the literature, interpretation of dN/dS in the context of MutSel is also discussed.
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Affiliation(s)
- Christopher T Jones
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia
| | - Noor Youssef
- Department of Biology, Dalhousie University, Halifax, Nova Scotia
| | - Edward Susko
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia.,Center for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia
| | - Joseph P Bielawski
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia.,Department of Biology, Dalhousie University, Halifax, Nova Scotia.,Center for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia
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Schoggins JW, Wilson SJ, Panis M, Murphy MY, Jones CT, Bieniasz P, Rice CM. Corrigendum: A diverse range of gene products are effectors of the type I interferon antiviral response. Nature 2015; 525:144. [PMID: 26153858 DOI: 10.1038/nature14554] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Borowska J, Jones CT, Deska-Gauthier D, Zhang Y. V3 interneuron subpopulations in the mouse spinal cord undergo distinctive postnatal maturation processes. Neuroscience 2015; 295:221-8. [PMID: 25800308 DOI: 10.1016/j.neuroscience.2015.03.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 02/12/2015] [Accepted: 03/12/2015] [Indexed: 02/08/2023]
Abstract
Mice develop weight-bearing locomotion within the first 2-3 weeks of birth, a period during which motoneurons (MNs) and interneurons (INs) that control locomotor activities undergo rapid maturation. In this study, we investigate the maturation of two subpopulations of V3 INs in the mouse spinal cord during this period. To do this, we conducted whole-cell patch-clamp recordings of tdTomato fluorescent protein-expressing spinal V3 INs from Sim1(Cre/+);tdTom mice at post-natal day (P) 0, P4, P9 and P14 and compared their properties to those at P21. Combining electrophysiology with computational analyses, we show that dorsal and ventral V3 subpopulations are physiologically distinct at birth, but the electrophysiological properties of V3 INs change significantly during the first three post-natal weeks. We further reveal that there are multiple developmental phases of both V3 subpopulations during the maturation process. The different developmental trajectories of physiological properties also coincide with changes in an animal's locomotor behavior. These properties likely reflect the differential functions of V3 subpopulations in maturing spinal locomotor circuits.
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Affiliation(s)
- J Borowska
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - C T Jones
- Department of Mathematics & Statistics, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - D Deska-Gauthier
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Y Zhang
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
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Blacklaws J, Deska-Gauthier D, Jones CT, Petracca YL, Liu M, Zhang H, Fawcett JP, Glover JC, Lanuza GM, Zhang Y. Sim1 is required for the migration and axonal projections of V3 interneurons in the developing mouse spinal cord. Dev Neurobiol 2015; 75:1003-17. [PMID: 25652362 DOI: 10.1002/dneu.22266] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/15/2015] [Accepted: 01/16/2015] [Indexed: 11/09/2022]
Abstract
V3 spinal interneurons (INs) are a group of excitatory INs that play a crucial role in producing balanced and stable gaits in vertebrate animals. In the developing mouse spinal cord, V3 INs arise from the most ventral progenitor domain and form anatomically distinctive subpopulations in adult spinal cords. They are marked by the expression of transcription factor Sim1 postmitotically, but the function of Sim1 in V3 development remains unknown. Here, we used Sim1(Cre) ;tdTomato mice to trace the fate of V3 INs in a Sim1 mutant versus control genetic background during development. In Sim1 mutants, V3 INs are produced normally and maintain a similar position and organization as in wild types before E12.5. Further temporal analysis revealed that the V3 INs in the mutants failed to migrate properly to form V3 subgroups along the dorsoventral axis of the spinal cord. At birth, in the Sim1 mutant the number of V3 INs in the ventral subgroup was normal, but they were significantly reduced in the dorsal subgroup with a concomitant increase in the intermediate subgroup. Retrograde labeling at lumbar level revealed that loss of Sim1 led to a reduction in extension of contralateral axon projections both at E14.5 and P0 without affecting ipsilateral axon projections. These results demonstrate that Sim1 is essential for proper migration and the guidance of commissural axons of the spinal V3 INs.
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Affiliation(s)
- Jake Blacklaws
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2
| | - Dylan Deska-Gauthier
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2
| | - Christopher T Jones
- Department of Mathematics & Statistics, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2
| | - Yanina L Petracca
- Developmental Neurobiology Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET). Av Patricias Argentinas 435, Buenos Aires, 1405, Argentina
| | - Mingwei Liu
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2
| | - Han Zhang
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2
| | - James P Fawcett
- Departments of Pharmacology and Surgery, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2
| | - Joel C Glover
- Department of Physiology, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Guillermo M Lanuza
- Developmental Neurobiology Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET). Av Patricias Argentinas 435, Buenos Aires, 1405, Argentina
| | - Ying Zhang
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2
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14
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Barnes-Seeman D, Boiselle C, Capacci-Daniel C, Chopra R, Hoffmaster K, Jones CT, Kato M, Lin K, Ma S, Pan G, Shu L, Wang J, Whiteman L, Xu M, Zheng R, Fu J. Design and synthesis of lactam–thiophene carboxylic acids as potent hepatitis C virus polymerase inhibitors. Bioorg Med Chem Lett 2014; 24:3979-85. [DOI: 10.1016/j.bmcl.2014.06.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 06/08/2014] [Accepted: 06/11/2014] [Indexed: 10/25/2022]
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15
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Kim HY, Li X, Jones CT, Rice CM, Garcia JM, Genovesio A, Hansen MAE, Windisch MP. Development of a multiplex phenotypic cell-based high throughput screening assay to identify novel hepatitis C virus antivirals. Antiviral Res 2013; 99:6-11. [PMID: 23660623 DOI: 10.1016/j.antiviral.2013.04.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 04/24/2013] [Accepted: 04/27/2013] [Indexed: 01/29/2023]
Abstract
Hepatitis C virus (HCV) infection is a global health concern with chronic liver damage threatening 3% of the world's population. To date, the standard of care is a combination of pegylated interferon-alpha with ribavirin, and recently two direct acting antivirals have entered the clinics. However, because of side effects, drug resistance and viral genotype-specific differences in efficacy current and potentially also future therapies have their limitations. Here, we describe the development of a phenotypic high-throughput assay to identify new cross-genotype inhibitors with novel mechanism of action, by combining a genotype (gt) 1 replicon with the infectious HCV gt2 cell culture system. To develop this phenotypic multiplex assay, HCV reporter cells expressing RFP-NLS-IPS and gt1b replicon cells expressing NS5A-GFP were co-plated and treated with compounds followed by inoculation with gt2a HCV. At 72h post treatment, RFP translocation as a marker for HCV infection and GFP fluorescence intensity as a marker for gt1 RNA replication were measured. Additionally, the total cell number, which serves as an indicator of cytotoxicity, was determined. This phenotypic strategy supports multi-parameter data acquisition from a single well to access cross-genotypic activity, provides an indication of the stage of the viral life cycle targeted, and also assesses compound cytotoxicity. Taken together, this multiplex phenotypic platform facilitates the identification of novel compounds for drug development and chemical probes for continuing efforts to understand the HCV life cycle.
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Affiliation(s)
- Hee-Young Kim
- Applied Molecular Virology, Institut Pasteur Korea, 696 Sampyeong-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, South Korea
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16
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Law JLM, Chen C, Wong J, Hockman D, Santer DM, Frey SE, Belshe RB, Wakita T, Bukh J, Jones CT, Rice CM, Abrignani S, Tyrrell DL, Houghton M. A hepatitis C virus (HCV) vaccine comprising envelope glycoproteins gpE1/gpE2 derived from a single isolate elicits broad cross-genotype neutralizing antibodies in humans. PLoS One 2013; 8:e59776. [PMID: 23527266 PMCID: PMC3602185 DOI: 10.1371/journal.pone.0059776] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 02/18/2013] [Indexed: 12/20/2022] Open
Abstract
Although a cure for HCV is on the near horizon, emerging drug cocktails will be expensive, associated with side-effects and resistance making a global vaccine an urgent priority given the estimated high incidence of infection around the world. Due to the highly heterogeneous nature of HCV, an effective HCV vaccine which could elicit broadly cross-neutralizing antibodies has represented a major challenge. In this study, we tested for the presence of cross-neutralizing antibodies in human volunteers who were immunized with recombinant glycoproteins gpE1/gpE2 derived from a single HCV strain (HCV1 of genotype 1a). Cross neutralization was tested in Huh-7.5 human hepatoma cell cultures using infectious recombinant HCV (HCVcc) expressing structural proteins of heterologous HCV strains from all known major genotypes, 1–7. Vaccination induced significant neutralizing antibodies against heterologous HCV genotype 1a virus which represents the most common genotype in North America. Of the 16 vaccinees tested, 3 were selected on the basis of strong 1a virus neutralization for testing of broad cross-neutralizing responses. At least 1 vaccinee was shown to elicit broad cross-neutralization against all HCV genotypes. Although observed in only a minority of vaccinees, our results prove the key concept that a vaccine derived from a single strain of HCV can elicit broad cross-neutralizing antibodies against all known major genotypes of HCV and provide considerable encouragement for the further development of a human vaccine against this common, global pathogen.
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Affiliation(s)
- John Lok Man Law
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
- * E-mail: (JLML); (MH)
| | - Chao Chen
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Jason Wong
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Darren Hockman
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Deanna M. Santer
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Sharon E. Frey
- Department of Internal Medicine, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Robert B. Belshe
- Department of Internal Medicine, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Takaji Wakita
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Jens Bukh
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christopher T. Jones
- Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, New York, United States of America
| | - Charles M. Rice
- Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, New York, United States of America
| | | | - D. Lorne Tyrrell
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Michael Houghton
- Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
- * E-mail: (JLML); (MH)
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17
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Meuleman P, Catanese MT, Verhoye L, Desombere I, Farhoudi A, Jones CT, Sheahan T, Grzyb K, Cortese R, Rice CM, Leroux-Roels G, Nicosia A. A human monoclonal antibody targeting scavenger receptor class B type I precludes hepatitis C virus infection and viral spread in vitro and in vivo. Hepatology 2012; 55:364-72. [PMID: 21953761 PMCID: PMC3262867 DOI: 10.1002/hep.24692] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 09/14/2011] [Indexed: 12/21/2022]
Abstract
UNLABELLED Endstage liver disease caused by chronic hepatitis C virus (HCV) infection is the leading indication for liver transplantation in the Western world. However, immediate reinfection of the grafted donor liver by circulating virus is inevitable and liver disease progresses much faster than the original disease. Standard antiviral therapy is not well tolerated and usually ineffective in liver transplant patients, whereas anti-HCV immunotherapy is hampered by the extreme genetic diversity of the virus and its ability to spread by way of cell-cell contacts. We generated a human monoclonal antibody against scavenger receptor class B type I (SR-BI), monoclonal antibody (mAb)16-71, which can efficiently prevent infection of Huh-7.5 hepatoma cells and primary hepatocytes by cell-culture-derived HCV (HCVcc). Using an Huh7.5 coculture system we demonstrated that mAb16-71 interferes with direct cell-to-cell transmission of HCV. Finally we evaluated the in vivo efficacy of mAb16-71 in "human liver urokinase-type plasminogen activator, severe combined immune deficiency (uPA-SCID) mice" (chimeric mice). A 2-week anti-SR-BI therapy that was initiated 1 day before viral inoculation completely protected all chimeric mice from infection with serum-derived HCV of different genotypes. Moreover, a 9-day postexposure therapy that was initiated 3 days after viral inoculation (when viremia was already observed in the animals) suppressed the rapid viral spread observed in untreated control animals. After cessation of anti-SR-BI-specific antibody therapy, a rise of the viral load was observed. CONCLUSION Using in vitro cell culture and human liver-chimeric mouse models, we show that a human mAb targeting the HCV coreceptor SR-BI completely prevents infection and intrahepatic spread of multiple HCV genotypes. This strategy may be an efficacious way to prevent infection of allografts following liver transplantation in chronic HCV patients, and may even hold promise for the prevention of virus rebound during or following antiviral therapy.
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Affiliation(s)
- Philip Meuleman
- Center for Vaccinology, Ghent University and Hospital, Gent, Belgium.
| | | | - Lieven Verhoye
- Center for Vaccinology, Ghent University and Hospital, Gent, Belgium
| | | | - Ali Farhoudi
- Center for Vaccinology, Ghent University and Hospital, Gent, Belgium
| | - Christopher T. Jones
- Center for the study of Hepatitis C, The Rockefeller University, New York, NY, USA
| | - Timothy Sheahan
- Center for the study of Hepatitis C, The Rockefeller University, New York, NY, USA
| | | | | | - Charles M Rice
- Center for the study of Hepatitis C, The Rockefeller University, New York, NY, USA
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18
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Andrus L, Marukian S, Jones CT, Catanese MT, Sheahan TP, Schoggins JW, Barry WT, Dustin LB, Trehan K, Ploss A, Bhatia SN, Rice CM. Expression of paramyxovirus V proteins promotes replication and spread of hepatitis C virus in cultures of primary human fetal liver cells. Hepatology 2011; 54:1901-12. [PMID: 22144107 PMCID: PMC3233237 DOI: 10.1002/hep.24557] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 07/01/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED Here we demonstrate that primary cultures of human fetal liver cells (HFLC) reliably support infection with laboratory strains of hepatitis C virus (HCV), although levels of virus replication vary significantly between different donor cell preparations and frequently decline in a manner suggestive of active viral clearance. To investigate possible contributions of the interferon (IFN) system to control HCV infection in HFLC, we exploited the well-characterized ability of paramyxovirus (PMV) V proteins to counteract both IFN induction and antiviral signaling. The V proteins of measles virus (MV) and parainfluenza virus 5 (PIV5) were introduced into HFLC using lentiviral vectors encoding a fluorescent reporter for visualization of HCV-infected cells. V protein-transduced HFLC supported enhanced (10 to 100-fold) levels of HCV infection relative to untransduced or control vector-transduced HFLC. Infection was assessed by measurement of virus-driven luciferase, by assays for infectious HCV and viral RNA, and by direct visualization of HCV-infected hepatocytes. Live cell imaging between 48 and 119 hours postinfection demonstrated little or no spread of infection in the absence of PMV V protein expression. In contrast, V protein-transduced HFLC showed numerous HCV infection events. V protein expression efficiently antagonized the HCV-inhibitory effects of added IFNs in HFLC. In addition, induction of the type III IFN, IL29, following acute HCV infection was inhibited in V protein-transduced cultures. CONCLUSION These studies suggest that the cellular IFN response plays a significant role in limiting the spread of HCV infection in primary hepatocyte cultures. Strategies aimed at dampening this response may be key to further development of robust HCV culture systems, enabling studies of virus pathogenicity and the mechanisms by which HCV spreads in its natural host cell population.
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Affiliation(s)
- Linda Andrus
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, NY 10021, USA.
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19
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Marukian S, Andrus L, Sheahan TP, Jones CT, Charles ED, Ploss A, Rice CM, Dustin LB. Hepatitis C virus induces interferon-λ and interferon-stimulated genes in primary liver cultures. Hepatology 2011; 54:1913-23. [PMID: 21800339 PMCID: PMC3219820 DOI: 10.1002/hep.24580] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
UNLABELLED Hepatitis C virus (HCV) replication in primary liver cells is less robust than that in hepatoma cell lines, suggesting that innate antiviral mechanisms in primary cells may limit HCV replication or spread. Here we analyzed the expression of 47 genes associated with interferon (IFN) induction and signaling following HCV infection of primary human fetal liver cell (HFLC) cultures from 18 different donors. We report that cell culture-produced HCV (HCVcc) induced expression of Type III (λ) IFNs and of IFN-stimulated genes (ISGs). Little expression of Type I IFNs was detected. Levels of IFNλ and ISG induction varied among donors and, often, between adapted and nonadapted HCV chimeric constructs. Higher levels of viral replication were associated with greater induction of ISGs and of λ IFNs. Gene induction was dependent on HCV replication, as ultraviolet light-inactivated virus was not stimulatory and an antiviral drug, 2'-C-methyladenosine, reduced induction of λ IFNs and ISGs. The level of IFNλ protein induced was sufficient to inhibit HCVcc infection of naïve cultures. CONCLUSION Together, these results indicate that despite its reported abilities to blunt the induction of an IFN response, HCV infection is capable of inducing antiviral cytokines and pathways in primary liver cell cultures. Induction of ISGs and λ IFNs may limit the growth and spread of HCV in primary cell cultures and in the infected liver. HCV infection of HFLC may provide a useful model for the study of gene induction by HCV in vivo.
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Affiliation(s)
- Svetlana Marukian
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY
| | - Linda Andrus
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY
| | - Timothy P. Sheahan
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY
| | - Christopher T. Jones
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY
| | - Edgar D. Charles
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY
| | - Alexander Ploss
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY
| | - Charles M. Rice
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY
| | - Lynn B. Dustin
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY
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20
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Dorner M, Horwitz JA, Robbins JB, Barry WT, Feng Q, Mu K, Jones CT, Schoggins JW, Catanese MT, Burton DR, Law M, Rice CM, Ploss A. A genetically humanized mouse model for hepatitis C virus infection. Nature 2011; 474:208-11. [PMID: 21654804 PMCID: PMC3159410 DOI: 10.1038/nature10168] [Citation(s) in RCA: 282] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 04/28/2011] [Indexed: 02/06/2023]
Abstract
Hepatitis C virus (HCV) remains a major medical problem. Antiviral treatment is only partially effective and a vaccine does not exist. Development of more effective therapies has been hampered by the lack of a suitable small animal model. Although xenotransplantation of immunodeficient mice with human hepatocytes has shown promise, these models are subject to important challenges. Building on the previous observation that CD81 and occludin comprise the minimal human factors required to render mouse cells permissive to HCV entry in vitro, we attempted murine humanization via a genetic approach. Here we show that expression of two human genes is sufficient to allow HCV infection of fully immunocompetent inbred mice. We establish a precedent for applying mouse genetics to dissect viral entry and validate the role of scavenger receptor type B class I for HCV uptake. We demonstrate that HCV can be blocked by passive immunization, as well as showing that a recombinant vaccinia virus vector induces humoral immunity and confers partial protection against heterologous challenge. This system recapitulates a portion of the HCV life cycle in an immunocompetent rodent for the first time, opening opportunities for studying viral pathogenesis and immunity and comprising an effective platform for testing HCV entry inhibitors in vivo.
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Affiliation(s)
- Marcus Dorner
- Center for the Study of Hepatitis C, The Rockefeller University, New York, New York 10065, USA
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21
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Abstract
Approximately 2% of the worldwide population is infected with hepatitis C virus (HCV), the major causative agent of non-A, non-B hepatitis. Although substantial progress has been made in developing tools to dissect the viral life cycle, most in vitro studies rely on hepatoma cell lines, which are functionally disparate from the natural in vivo target of the virus – hepatocytes. To gain insights into virus–host interactions, there is a need for HCV-model systems that more closely mimic the physiological environment of the liver. Here, we discuss recent advances in culture and detection systems that facilitate the study of HCV in primary cells. Use of these new models may help bridge the gap between in vitro studies and clinical research.
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Affiliation(s)
- Timothy Sheahan
- Center for the Study of Hepatitis C, The Rockefeller University, 1230 York Avenue, Box 64, New York, NY 10065, USA
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22
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Abstract
Viruses of the Flaviviridae family, including hepatitis C, dengue and bovine viral diarrhoea, are responsible for considerable morbidity and mortality worldwide. Recent advances in our understanding of virion assembly have uncovered commonalities among distantly related members of this family. We discuss the emerging hypothesis that physical virion components are not alone in forming the infectious particle, but that non-structural proteins are intimately involved in orchestrating morphogenesis. Pinpointing the roles of Flaviviridae proteins in virion production could reveal new avenues for antiviral therapeutics.
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23
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Marukian S, Jones CT, Andrus L, Evans MJ, Ritola KD, Charles ED, Rice CM, Dustin LB. Cell culture-produced hepatitis C virus does not infect peripheral blood mononuclear cells. Hepatology 2008; 48:1843-50. [PMID: 19003912 PMCID: PMC2592497 DOI: 10.1002/hep.22550] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
UNLABELLED Hepatitis C virus (HCV) replicates primarily in the liver, but HCV RNA has been observed in association with other tissues and cells including B and T lymphocytes, monocytes, and dendritic cells. We have taken advantage of a recently described, robust system that fully recapitulates HCV entry, replication and virus production in vitro to re-examine the issue of HCV infection of blood cell subsets. The HCV replicase inhibitor 2'C-methyl adenosine was used to distinguish HCV RNA replication from RNA persistence. Whereas cell culture-grown HCV replicated in Huh-7.5 hepatoma cells, no HCV replication was detected in B or T lymphocytes, monocytes, macrophages, or dendritic cells from healthy donors. No blood cell subset tested expressed significant levels of Claudin-1, a tight junction protein needed for HCV infection of Huh-7.5 cells. A B cell line expressing high levels of Claudin-1, CD81, and scavenger receptor BI remained resistant to HCV pseudoparticle infection. We bypassed the block in HCV entry by transfecting HCV RNA into blood cell subsets. Transfected RNA was not detectably translated and induced high levels of interferon-alpha. Supernatants from HCV RNA-transfected macrophages inhibited HCV replication in Huh-7.5 cells. CONCLUSION We conclude that multiple blocks prevent blood cells from supporting HCV infection.
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Affiliation(s)
| | | | | | | | | | | | | | - Lynn B. Dustin
- Corresponding author: Lynn B. Dustin, Ph.D., Center for the Study of Hepatitis C, The Rockefeller University, 1230 York Ave., New York, NY 10065, Phone: 212-327-7067, Fax: 212-327-7048,
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24
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Jones CT, Rolph TP. Metabolic events associated with the preparation of the fetus for independent life. Ciba Found Symp 2008; 86:214-33. [PMID: 6802587 DOI: 10.1002/9780470720684.ch10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The metabolic changes late in fetal development that are essential for neonatal survival are discussed. In many species gluconeogenesis develops before birth but provides substrate for intracellular biosynthesis and not for glucose production because of low activities of glucose 6-phosphate translocase. At the time of glycogen deposition in species with a relatively mature brain at birth the translocase develops and glucagon and adrenaline can stimulate glucose production and synthesis to elevate blood glucose concentrations both pre- and postnatally. The other metabolic fuel accumulated before birth, fat, can also be mobilized prenatally and in fetuses that are relatively mature at birth it may be used as an alternative fuel. The fetal rat brain can oxidize fatty acids and the brain of fetuses such as that of the guinea-pig and man can oxidize ketone bodies before birth. The timing and degree of oxidation of ketone bodies relates to the timing of myelination and protects the brain against hypoglycaemia. These late changes in development are associated with a sharp increase in plasma cortisol and adrenaline concentrations and a high fetal insulin concentration.
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25
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Murray CL, Jones CT, Tassello J, Rice CM. Alanine scanning of the hepatitis C virus core protein reveals numerous residues essential for production of infectious virus. J Virol 2007; 81:10220-31. [PMID: 17634240 PMCID: PMC2045476 DOI: 10.1128/jvi.00793-07] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hepatitis C virus (HCV) is an important human pathogen affecting an estimated 3% of the world's population. Recent advances have enabled in vitro propagation of the virus and allow assembly and egress to be investigated for the first time. As a component of the virion, the HCV core protein likely functions primarily in infectious virus production, although little is known about the determinants of this activity. To investigate the roles of core in the viral life cycle, we performed a comprehensive deletion and alanine scanning mutagenesis study of this protein in the context of a genotype 2a reporter virus. We have confirmed that core protein is essential for infectious virion production and have identified numerous residues required for this role. The infectivity of several assembly-defective core mutants could be rescued by compensatory mutations identified in p7 and NS2, suggesting genetic interactions with core and highlighting the importance of these nonstructural proteins in infectious virion morphogenesis.
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Affiliation(s)
- Catherine L Murray
- Laboratory of Virology and Infectious Disease, Center for the Study of Hepatitis C, The Rockefeller University, 1230 York Ave., New York, NY 10021, USA
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26
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Patkar CG, Jones CT, Chang YH, Warrier R, Kuhn RJ. Functional requirements of the yellow fever virus capsid protein. J Virol 2007; 81:6471-81. [PMID: 17526891 PMCID: PMC1900127 DOI: 10.1128/jvi.02120-06] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 03/23/2007] [Indexed: 11/20/2022] Open
Abstract
Although it is known that the flavivirus capsid protein is essential for genome packaging and formation of infectious particles, the minimal requirements of the dimeric capsid protein for virus assembly/disassembly have not been characterized. By use of a trans-packaging system that involved packaging a yellow fever virus (YFV) replicon into pseudo-infectious particles by supplying the YFV structural proteins using a Sindbis virus helper construct, the functional elements within the YFV capsid protein (YFC) were characterized. Various N- and C-terminal truncations, internal deletions, and point mutations of YFC were analyzed for their ability to package the YFV replicon. Consistent with previous reports on the tick-borne encephalitis virus capsid protein, YFC demonstrates remarkable functional flexibility. Nearly 40 residues of YFC could be removed from the N terminus while the ability to package replicon RNA was retained. Additionally, YFC containing a deletion of approximately 27 residues of the C terminus, including a complete deletion of C-terminal helix 4, was functional. Internal deletions encompassing the internal hydrophobic sequence in YFC were, in general, tolerated to a lesser extent. Site-directed mutagenesis of helix 4 residues predicted to be involved in intermonomeric interactions were also analyzed, and although single mutations did not affect packaging, a YFC with the double mutation of leucine 81 and valine 88 was nonfunctional. The effects of mutations in YFC on the viability of YFV infection were also analyzed, and these results were similar to those obtained using the replicon packaging system, thus underscoring the flexibility of YFC with respect to the requirements for its functioning.
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Affiliation(s)
- Chinmay G Patkar
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
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27
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Abstract
Hepatitis C virus (HCV) infection is a global health concern affecting an estimated 3% of the world's population. Recently, cell culture systems have been established, allowing recapitulation of the complete virus life cycle for the first time. Since the HCV proteins p7 and NS2 are not predicted to be major components of the virion, nor are they required for RNA replication, we investigated whether they might have other roles in the viral life cycle. Here we utilize the recently described infectious J6/JFH chimera to establish that the p7 and NS2 proteins are essential for HCV infectivity. Furthermore, unprocessed forms of p7 and NS2 were not required for this activity. Mutation of two conserved basic residues, previously shown to be important for the ion channel activity of p7 in vitro, drastically impaired infectious virus production. The protease domain of NS2 was required for infectivity, whereas its catalytic active site was dispensable. We conclude that p7 and NS2 function at an early stage of virion morphogenesis, prior to the assembly of infectious virus.
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Affiliation(s)
- Christopher T Jones
- Laboratory of Virology and Infectious Disease, Center for the Study of Hepatitis C, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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28
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Tscherne DM, Evans MJ, von Hahn T, Jones CT, Stamataki Z, McKeating JA, Lindenbach BD, Rice CM. Superinfection exclusion in cells infected with hepatitis C virus. J Virol 2007; 81:3693-703. [PMID: 17287280 PMCID: PMC1866098 DOI: 10.1128/jvi.01748-06] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Superinfection exclusion is the ability of an established virus infection to interfere with infection by a second virus. In this study, we found that Huh-7.5 cells acutely infected with hepatitis C virus (HCV) genotype 2a (chimeric strain J6/JFH) and cells harboring HCV genotype 1a, 1b, or 2a full-length or subgenomic replicons were resistant to infection with cell culture-produced HCV (HCVcc). Replicon-containing cells became permissive for HCVcc infection after treatment with an HCV-specific protease inhibitor. With the exception of cells harboring a J6/JFH-FLneo replicon, infected or replicon-containing cells were permissive for HCV pseudoparticle (HCVpp) entry, demonstrating a postentry superinfection block downstream of primary translation. The surprising resistance of J6/JFH-FLneo replicon-containing cells to HCVpp infection suggested a defect in virus entry. This block was due to reduced expression of the HCV coreceptor CD81. Further analyses indicated that J6/JFH may be toxic for cells expressing high levels of CD81, thus selecting for a CD81(low) population. CD81 down regulation was not observed in acutely infected cells, suggesting that this may not be a general mechanism of HCV superinfection exclusion. Thus, HCV establishes superinfection exclusion at a postentry step, and this effect is reversible by treatment of infected cells with antiviral compounds.
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Affiliation(s)
- Donna M Tscherne
- Laboratory of Virology and Infectious Diseases, Center for the Study of Hepatitis C, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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Abstract
Hepatitis C virus (HCV) entry is dependent on CD81. To investigate whether the CD81 sequence is a determinant of HCV host range, we expressed a panel of diverse CD81 proteins and tested their ability to interact with HCV. CD81 large extracellular loop (LEL) sequences were expressed as recombinant proteins; the human and, to a low level, the African green monkey sequences bound soluble HCV E2 (sE2) and inhibited infection by retrovirus pseudotype particles bearing HCV glycoproteins (HCVpp). In contrast, mouse or rat CD81 proteins failed to bind sE2 or to inhibit HCVpp infection. However, CD81 proteins from all species, when expressed in HepG2 cells, conferred susceptibility to infection by HCVpp and cell culture-grown HCV to various levels, with the rat sequence being the least efficient. Recombinant human CD81 LEL inhibited HCVpp infectivity only if present during the virus-cell incubation, consistent with a role for CD81 after virus attachment. Amino acid changes that abrogate sE2 binding (I182F, N184Y, and F186S, alone or in combination) were introduced into human CD81. All three amino acid changes in human CD81 resulted in a molecule that still supported HCVpp infection, albeit with reduced efficiency. In summary, there is a remarkable plasticity in the range of CD81 sequences that can support HCV entry, suggesting that CD81 polymorphism may contribute to, but alone does not define, the HCV susceptibility of a species. In addition, the capacity to support viral entry is only partially reflected by assays measuring sE2 interaction with recombinant or full-length CD81 proteins.
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Affiliation(s)
- Mike Flint
- Wyeth Research, 500 Arcola Road, S-1111, Collegeville, PA 19426, USA.
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30
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Tscherne DM, Jones CT, Evans MJ, Lindenbach BD, McKeating JA, Rice CM. Time- and temperature-dependent activation of hepatitis C virus for low-pH-triggered entry. J Virol 2006; 80:1734-41. [PMID: 16439530 PMCID: PMC1367161 DOI: 10.1128/jvi.80.4.1734-1741.2006] [Citation(s) in RCA: 311] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C virus (HCV) is an important human pathogen associated with chronic liver disease. Recently, based on a genotype 2a isolate, tissue culture systems supporting complete replication and infectious virus production have been developed. In this study, we used cell culture-produced infectious HCV to analyze the viral entry pathway into Huh-7.5 cells. Bafilomycin A1 and concanamycin A, inhibitors of vacuolar ATPases, prevented HCV entry when they were present prior to infection and had minimal effect on downstream replication events. HCV entry therefore appears to be pH dependent, requiring an acidified intracellular compartment. For many other enveloped viruses, acidic pH triggers an irreversible conformational change, which promotes virion-endosomal membrane fusion. Such viruses are often inactivated by low pH. In the case of HCV, exposure of virions to acidic pH followed by return to neutral pH did not affect their infectivity. This parallels the observation made for the related pestivirus bovine viral diarrhea virus. Low pH could activate the entry of cell surface-bound HCV but only after prolonged incubation at 37 degrees C. This suggests that there are rate-limiting, postbinding events that are needed to render HCV competent for low-pH-triggered entry. Such events may involve interaction with a cellular coreceptor or other factors but do not require cathepsins B and L, late endosomal proteases that activate Ebola virus and reovirus for entry.
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Affiliation(s)
- Donna M Tscherne
- Laboratory of Virology and Infectious Diseases, Center for the Study of Hepatitis C, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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31
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Jones CT, Patkar CG, Kuhn RJ. Construction and applications of yellow fever virus replicons. Virology 2005; 331:247-59. [PMID: 15629769 DOI: 10.1016/j.virol.2004.10.034] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2004] [Revised: 06/28/2004] [Accepted: 10/01/2004] [Indexed: 11/18/2022]
Abstract
Subgenomic replicons of yellow fever virus (YFV) were constructed to allow expression of heterologous reporter genes in a replication-dependent manner. Expression of the antibiotic resistance gene neomycin phosphotransferase II (Neo) from one of these YFV replicons allowed selection of a stable population of cells (BHK-REP cells) in which the YFV replicon persistently replicated. BHK-REP cells were successfully used to trans-complement replication-defective YFV replicons harboring large internal deletions within either the NS1 or NS3 proteins. Although replicons with large deletions in either NS1 or NS3 were trans-complemented in BHK-REP, replicons that contained deletions of NS3 were trans-complemented at lower levels. In addition, replicons that retained the N-terminal protease domain of NS3 in cis were trans-complemented with higher efficiency than replicons in which both the protease and helicase domains of NS3 were deleted. To study packaging of YFV replicons, Sindbis replicons were constructed that expressed the YFV structural proteins in trans. Using these Sindbis replicons, both replication-competent and trans-complemented, replication-defective YFV replicons could be packaged into pseudo-infectious particles (PIPs). Although these results eliminate a potential role of either NS1 or full-length NS3 in cis for packaging and assembly of the flavivirus virion, they do not preclude the possibility that these proteins may act in trans during these processes.
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Affiliation(s)
- Christopher T Jones
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
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32
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Ma L, Jones CT, Groesch TD, Kuhn RJ, Post CB. Solution structure of dengue virus capsid protein reveals another fold. Proc Natl Acad Sci U S A 2004; 101:3414-9. [PMID: 14993605 PMCID: PMC373476 DOI: 10.1073/pnas.0305892101] [Citation(s) in RCA: 254] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2003] [Accepted: 12/04/2003] [Indexed: 11/18/2022] Open
Abstract
Dengue virus is responsible for approximately 50-100 million infections, resulting in nearly 24,000 deaths annually. The capsid (C) protein of dengue virus is essential for specific encapsidation of the RNA genome, but little structural information on the C protein is available. We report the solution structure of the 200-residue homodimer of dengue 2 C protein. The structure provides, to our knowledge, the first 3D picture of a flavivirus C protein and identifies a fold that includes a large dimerization surface contributed by two pairs of helices, one of which has characteristics of a coiled-coil. NMR structure determination involved a secondary structure sorting approach to facilitate assignment of the intersubunit nuclear Overhauser effect interactions. The dimer of dengue C protein has an unusually high net charge, and the structure reveals an asymmetric distribution of basic residues over the surface of the protein. Nearly half of the basic residues lie along one face of the dimer. In contrast, the conserved hydrophobic region forms an extensive apolar surface at a dimer interface on the opposite side of the molecule. We propose a model for the interaction of dengue C protein with RNA and the viral membrane that is based on the asymmetric charge distribution of the protein and is consistent with previously reported results.
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Affiliation(s)
- Lixin Ma
- Department of Medicinal Chemistry, Purdue University, West Lafayette, IN 47907, USA
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33
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Abstract
The capsid proteins of two flaviviruses, yellow fever virus and dengue virus, were expressed in Escherichia coli and purified to near homogeneity suitable for biochemical characterization and structure determination by nuclear magnetic resonance. The oligomeric properties of the capsid protein in solution were investigated. In the absence of nucleic acid, both proteins were predominantly dimeric in solution. Further analysis of both proteins with far-UV circular dichroism spectroscopy indicated that they were largely alpha-helical. The secondary structure elements of the dengue virus capsid were determined by chemical shift indexing of the sequence-specific backbone resonance assignments. The dengue virus capsid protein devoid of its C-terminal signal sequence was found to be composed of four alpha helices. The longest alpha helix, 20 residues, is located at the C terminus and has an amphipathic character. In contrast, the N terminus was found to be unstructured and could be removed without disrupting the structural integrity of the protein.
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Affiliation(s)
- Christopher T Jones
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
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Haupt SG, Riley DR, Jones CT, Zhao J, McDevitt JT. Reversible modulation of Tc in conductive polymer/high temperature superconductor assemblies. J Am Chem Soc 2002. [DOI: 10.1021/ja00056a082] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kuhn RJ, Zhang W, Rossmann MG, Pletnev SV, Corver J, Lenches E, Jones CT, Mukhopadhyay S, Chipman PR, Strauss EG, Baker TS, Strauss JH. Structure of dengue virus: implications for flavivirus organization, maturation, and fusion. Cell 2002; 108:717-25. [PMID: 11893341 PMCID: PMC4152842 DOI: 10.1016/s0092-8674(02)00660-8] [Citation(s) in RCA: 1126] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The first structure of a flavivirus has been determined by using a combination of cryoelectron microscopy and fitting of the known structure of glycoprotein E into the electron density map. The virus core, within a lipid bilayer, has a less-ordered structure than the external, icosahedral scaffold of 90 glycoprotein E dimers. The three E monomers per icosahedral asymmetric unit do not have quasiequivalent symmetric environments. Difference maps indicate the location of the small membrane protein M relative to the overlaying scaffold of E dimers. The structure suggests that flaviviruses, and by analogy also alphaviruses, employ a fusion mechanism in which the distal beta barrels of domain II of the glycoprotein E are inserted into the cellular membrane.
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Affiliation(s)
- Richard J Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.
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36
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Abstract
The evaluation of patients with recurrent chest pain accounts for a significant proportion of the $274 billion annual cost of cardiovascular services in the United States. Our investigation examines the impact of coronary angiography on subsequent use of medical resources for evaluation of chest pain symptoms. The study seeks to determine whether a finding of noncritical coronary artery disease on cardiac catheterization leads to a reduced use of resources for subsequent evaluation and treatment of chest pain syndromes. Our study included 22 consecutive patients who had sought evaluation for chest pain symptoms, and who had persistence of symptoms after functional testing. Cardiac catheterization demonstrated angiographically mild coronary artery disease (stenosis less than 50%) in these patients. The patient cohort accounted for 22 emergency room evaluations and 41 ambulatory clinic evaluations in the 2.5 years before cardiac catheterization. In the 2.5-year period after catheterization, these patients had only 3 emergency room visits and 1 ambulatory clinic visit for chest pain evaluation (P < 0.001). There was a significant reduction in the number of prescriptions written for topical and oral nitrates (32% precatheterization vs. 5% postcatheterization, P < 0.04), but not of beta-blockers (26% vs. 21%, P = 0.53) or calcium blockers (32% vs. 32%, P = 1.0). Furthermore, most of the 21 surviving patients were found subsequently to have a noncardiac basis for their pain: pericarditis was felt to be the cause of chest pain in 4 patients, pulmonary disease in 7 patients, and gastrointestinal conditions in 8 patients. Diagnostic coronary arteriography may identify a subset of patients in whom a finding of noncritical coronary artery disease leads to a reduction in physician visits for evaluation of chest pain syndromes and reduced use of nitrates. In addition, when coronary artery disease is known to be mild, a noncardiac etiology for the chest pain can be sought. These results may decrease the use of expensive medical resources and encourage full occupational and lifestyle rehabilitation.
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Affiliation(s)
- R S Wright
- Mayo Physician Alliance for Clinical Trials Coordinating Center, Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota, USA.
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37
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Smith J, Bruley CK, Paton IR, Dunn I, Jones CT, Windsor D, Morrice DR, Law AS, Masabanda J, Sazanov A, Waddington D, Fries R, Burt DW. Differences in gene density on chicken macrochromosomes and microchromosomes. Anim Genet 2000; 31:96-103. [PMID: 10782207 DOI: 10.1046/j.1365-2052.2000.00565.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The chicken karyotype comprises six pairs of large macrochromosomes and 33 pairs of smaller microchromosomes. Cytogenetic evidence suggests that microchromosomes may be more gene-dense than macrochromosomes. In this paper, we compare the gene densities on macrochromosomes and microchromosomes based on sequence sampling of cloned genomic DNA, and from the distribution of genes mapped by genetic linkage and physical mapping. From these different approaches we estimate that microchromosomes are twice as gene-dense as macrochromosomes and show that sequence sampling is an effective means of gene discovery in the chicken. Using this method we have also detected a conserved linkage between the genes for serotonin 1D receptor (HTR1D) and the platelet-activating factor receptor protein gene (PTAFR) on chicken chromosome 5 and human chromosome 1p34.3. Taken together with its advantages as an experimental animal, and public access to genetic and physical mapping resources, the chicken is a useful model genome for studies on the structure, function and evolution of the vertebrate genome.
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Affiliation(s)
- J Smith
- Division of Molecular Biology, Roslin Institute (Edinburgh), Midlothian, UK
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Burt DW, Bruley C, Dunn IC, Jones CT, Ramage A, Law AS, Morrice DR, Paton IR, Smith J, Windsor D, Sazanov A, Fries R, Waddington D. The dynamics of chromosome evolution in birds and mammals. Nature 1999; 402:411-3. [PMID: 10586880 DOI: 10.1038/46555] [Citation(s) in RCA: 220] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Comparative mapping, which compares the location of homologous genes in different species, is a powerful tool for studying genome evolution. Comparative maps suggest that rates of chromosomal change in mammals can vary from one to ten rearrangements per million years. On the basis of these rates we would expect 84 to 600 conserved segments in a chicken comparison with human or mouse. Here we build comparative maps between these species and estimate that numbers of conserved segments are in the lower part of this range. We conclude that the organization of the human genome is closer to that of the chicken than the mouse and by adding comparative mapping results from a range of vertebrates, we identify three possible phases of chromosome evolution. The relative stability of genomes such as those of the chicken and human will enable the reconstruction of maps of ancestral vertebrates.
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Affiliation(s)
- D W Burt
- Roslin Institute (Edinburgh), Roslin, Midlothian, UK.
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Heryadi D, Jones CT, Yeager DL. A small optimal complete active space (CAS) for multiconfigurational spin tensor electron propagator method (MCSTEP) ionization potentials: Application to methane, acetylene, ethylene, and ethane. J Chem Phys 1997. [DOI: 10.1063/1.474871] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jones CT, Morrice DR, Paton IR, Burt DW. Gene homologs on human chromosome 15q21-q26 and a chicken microchromosome identify a new conserved segment. Mamm Genome 1997; 8:436-40. [PMID: 9166590 DOI: 10.1007/s003359900463] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The genes for insulin-like growth factor 1 receptor (IGF1R), aggrecan (AGC1), beta2-microglobulin (B2M), and an H6-related gene have been mapped to a single chicken microchromosome by genetic linkage analysis. In addition, a second H6-related gene was mapped to chicken macrochromosome 3. The Igf1r and Agc1 loci are syntenic on mouse Chr 7, together with Hmx3, an H6-like locus. This suggests that the H6-related locus, which maps to the chicken microchromosome in this study, is the homolog of mouse Hmx3. The IGF1R, AGC1, and B2M loci are located on human Chr 15, probably in the same order as found for this chicken microchromosome. This conserved segment, however, is not entirely conserved in the mouse and is split between Chr 7 (Igf1r-Agc) and 2 (B2m). This comparison also predicts that the HMX3 locus may map to the short arm of human Chr 15. The conserved segment defined by the IGF1R-AGC1-HMX3-B2M loci is approximately 21-35 Mb in length and probably covers the entire chicken microchromosome. These results suggest that a segment of human Chr 15 has been conserved as a chicken microchromosome. The significance of this result is discussed with reference to the evolution of the avian and mammalian genomes.
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Affiliation(s)
- C T Jones
- Roslin Institute (Edinburgh), Roslin, Midlothian, Scotland EH25 9PS, UK
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41
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Jones CT, Swingler RJ, Simpson SA, Brock DJ. Superoxide dismutase mutations in an unselected cohort of Scottish amyotrophic lateral sclerosis patients. J Med Genet 1995; 32:290-2. [PMID: 7643359 PMCID: PMC1050378 DOI: 10.1136/jmg.32.4.290] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mutations in the Cu/Zn superoxide dismutase (SOD1) gene are responsible for some cases of familial amyotrophic lateral sclerosis (ALS). We have shown that SOD1 mutations can also occur in apparently sporadic ALS. To establish how often this happens we have undertaken a study of the prevalence of SOD1 mutations in an unselected cohort of Scottish ALS patients, with both sporadic (n = 57) and familial (n = 10) disease. Single strand conformation polymorphism analysis was used to scan for new mutations, and selective restriction enzyme digestion to screen for 11 of the 20 SOD1 mutations published to date. We detected mutations in five (50%) of the familial ALS patients and also in four (7%) of the sporadic patients. One mutation, ile113thr, seems to be particularly prevalent in the Scottish population since it was detected in a total of 6/67 (9%) unrelated cases.
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Affiliation(s)
- C T Jones
- Human Genetics Unit, University of Edinburgh, Western General Hospital, UK
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42
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Jones CT, Edwards AV. Muscarinic involvement in vascular and adrenal medullary responses to splanchnic nerve stimulation in conscious calves. Experientia 1994; 50:931-5. [PMID: 7957767 DOI: 10.1007/bf01923481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Stimulation of the peripheral end of the right splanchnic nerve (4 Hz for 10 min) in the presence of hexamethonium caused a small but significant rise in mean aortic blood pressure which was subsequently abolished by atropine. There were also small but significant increases in the outputs of catecholamines, [Met5]-enkephalins and corticotrophin releasing factor (CRF) from the right adrenal gland. The catecholamine response was roughly halved after atropine while the outputs of enkephalins and CRF were unaffected. It is concluded that splanchnic sympathetic postganglionic neurones supplying the vasculature are completely blocked by cholinergic blockade whereas adrenal medullary responses persist in an attenuated form.
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Affiliation(s)
- C T Jones
- Laboratory of Cellular and Developmental Physiology, University of Oxford, England, UK
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Edwards AV, Jones CT. Effects of substance P on adrenal responses to acetylcholine in conscious calves. Am J Physiol 1994; 267:E447-53. [PMID: 7524340 DOI: 10.1152/ajpendo.1994.267.3.e447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The effect of intra-aortic infusions of substance P (SP; 10 or 20 pmol.min-1.kg-1) on adrenal responses to acetylcholine (4.5 nmol.min-1.kg-1 ia) have been investigated in functionally hypophysectomized calves given exogenous adrenocorticotropic hormone (0.7 pmol.min-1.kg-1). At the lower dose, SP had no effect on cortisol output. In contrast, SP inhibited the output of both catecholamines and enkephalins in response to acetylcholine, without affecting the output of corticotropin-releasing factor (CRF). Increasing the dose of SP to 20 pmol.min-1.kg-1 ia significantly reduced the outputs of both cortisol and CRF (P < 0.025 and 0.01 respectively). It is concluded that SP is capable of modulating both adrenal cortical and medullary responses to acetylcholine and that the latter are more sensitive to this influence than the former.
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Affiliation(s)
- A V Edwards
- Physiological Laboratory, University of Cambridge, United Kingdom
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44
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Abstract
We have been screening a cohort of 46 sporadic and 10 familial amyotrophic lateral sclerosis patients for mutations in the superoxide dismutase gene (SOD1) using a combination of SSCP and direct PCR sequencing. A novel missense mutation (Asp101Asn) has been detected in one sporadic patient and a previously reported mutation has been found in two familial cases.
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Affiliation(s)
- C T Jones
- Human Genetics Unit, University of Edinburgh, Western General Hospital
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45
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Abstract
A monoclonal antibody was made which identifies a 160-180 kDa structural protein in guinea pig cytomegalovirus (GPCMV) infected cells by Western blot using non-reducing conditions. This protein was shown to be a virion structural protein by purification of GPCMV on a density viscosity gradient and Western blot analysis. Phosphoanacetic acid (PAA) experiments suggest that the protein is a late GPCMV protein. In vitro the monoclonal antibody labels a cytoplasmic protein in infected guinea pig embryo fibroblasts by 12 h postinfection. The monoclonal antibody also identifies GPCMV infected cells in vivo in paraffin embedded formalin fixed tissue.
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Affiliation(s)
- C T Jones
- Department of Pathology, University of Maryland, School of Medicine, Baltimore 21201
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Abstract
Intra-aortic infusions of pituitary adenylate cyclase-activating peptide-(1-38) (PACAP) produced a dose-related fall in aortic blood pressure over the range of 4-40 pmol.min-1.kg-1 in the presence of exogenous adrenocorticotropic hormone-(1-24) (ACTH, 2 ng.min-1.kg-1 i.v.; P < 0.01). At the higher dose there was a significant fall in adrenal vascular resistance in the absence, but not in the presence, of ACTH. PACAP also produced a dose-related increase in right adrenal cortisol output over the same range, which was significantly greater in the absence of exogenous ACTH (P < 0.01). At the higher dose, PACAP produced small but significant increases in adrenal epinephrine and norepinephrine output (P < 0.01) both in the presence and the absence of ACTH. There was also a small rise in Met5-enkephalin output, and corticotrophin-releasing factor (CRF) was released in the presence, but not in the absence, of ACTH. It is concluded that PACAP is capable of exerting potent steroidogenic and vasodilator effects in the adrenal gland in the normal conscious calf and of releasing significant amounts of catecholamines, enkephalins, and CRF from the adrenal medulla. These findings identify PACAP as a candidate neuromodulator in the adrenal gland in this species.
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Affiliation(s)
- A V Edwards
- Physiological Laboratory, University of Cambridge, United Kingdom
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47
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Jones CT, Swingler RJ, Brock DJ. Identification of a novel SOD1 mutation in an apparently sporadic amyotrophic lateral sclerosis patient and the detection of Ile113Thr in three others. Hum Mol Genet 1994; 3:649-50. [PMID: 8069312 DOI: 10.1093/hmg/3.4.649] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- C T Jones
- Human Genetics Unit, University of Edinburgh, Western General Hospital, UK
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48
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49
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Edwards AV, Jones CT. Autonomic control of adrenal function. J Anat 1993; 183 ( Pt 2):291-307. [PMID: 8300417 PMCID: PMC1259909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Recent studies of adrenal function in conscious calves are reviewed. These have involved collecting the whole of the adrenal effluent blood from the right adrenal gland at intervals and, where necessary, prior functional hypophysectomy by destruction of the pituitary stalk under general halothane anaesthesia 3 d previously. The adrenal medulla was found to release numerous neuropeptides, in addition to catecholamines, in response to stimulation of the peripheral end of the right splanchnic nerve, which was carried out below behavioural threshold. Many of these responses were enhanced by stimulating intermittently at a relatively high frequency. Intra-aortic infusions of a relatively low dose of acetylcholine (4.5 nmol min-1 kg-1) elicited similar responses. In the adrenal cortex, agonists which either potentiated the steroidogenic response to ACTH or exerted a direct steroidogenic action included VIP, CGRP, CRF and ACh acting via muscarinic receptors. Stimulation of the peripheral end of the right splanchnic nerve strongly potentiated the steroidogenic response to ACTH and there is compelling evidence that the innervation normally plays an important part in cortisol secretion.
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Affiliation(s)
- A V Edwards
- Physiological Laboratory, University of Cambridge, UK
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50
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Jones CT. Criminalization of health care. J S C Med Assoc 1993; 89:439-41. [PMID: 8231119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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