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Onyango DO, Selman BG, Rose JL, Ellison CA, Nash JF. Comparison between endocrine activity assessed using ToxCast/Tox21 database and human plasma concentration of sunscreen active ingredients/UV filters. Toxicol Sci 2023; 196:25-37. [PMID: 37561120 PMCID: PMC10613966 DOI: 10.1093/toxsci/kfad082] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023] Open
Abstract
Sunscreen products are composed of ultraviolet (UV) filters and formulated to reduce exposure to sunlight thereby lessening skin damage. Concerns have been raised regarding the toxicity and potential endocrine disrupting (ED) effects of UV filters. The ToxCast/Tox21 program, that is, CompTox, is a high-throughput in vitro screening database of chemicals that identify adverse outcome pathways, key events, and ED potential of chemicals. Using the ToxCast/Tox21 database, octisalate, homosalate, octocrylene, oxybenzone, octinoxate, and avobenzone, 6 commonly used organic UV filters, were found to have been evaluated. These UV filters showed low potency in these bioassays with most activity detected above the range of the cytotoxic burst. The pathways that were most affected were the cell cycle and the nuclear receptor pathways. Most activity was observed in liver and kidney-based bioassays. These organic filters and their metabolites showed relatively weak ED activity when tested in bioassays measuring estrogen receptor (ER), androgen receptor (AR), thyroid receptor, and steroidogenesis activity. Except for oxybenzone, all activity in the endocrine assays occurred at concentrations greater than the cytotoxic burst. Moreover, except for oxybenzone, plasma concentrations (Cmax) measured in humans were at least 100× lower than bioactive (AC50/ACC) concentrations that produced a response in ToxCast/Tox21 assays. These data are consistent with in vivo animal/human studies showing weak or negligible endocrine activity. In sum, when considered as part of a weight-of-evidence assessment and compared with measured plasma concentrations, the results show these organic UV filters have low intrinsic biological activity and risk of toxicity including endocrine disruption in humans.
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Affiliation(s)
- David O Onyango
- Global Product Stewardship, The Procter & Gamble Company, Mason, Ohio 45040, USA
| | - Bastian G Selman
- Global Product Stewardship, The Procter & Gamble Company, Mason, Ohio 45040, USA
| | - Jane L Rose
- Global Product Stewardship, The Procter & Gamble Company, Mason, Ohio 45040, USA
| | - Corie A Ellison
- Global Product Stewardship, The Procter & Gamble Company, Mason, Ohio 45040, USA
| | - J F Nash
- Global Product Stewardship, The Procter & Gamble Company, Mason, Ohio 45040, USA
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Ellison CA, Arnot JA, Felter SP, Daston GP, Becker RA, Toose L, Armitage JM, Sangion A, Looky A, Brown TN, Li L. Letter to the editor regarding recent publication titled "Developing an internal threshold of toxicological concern (iTTC)" by Arnot et al. (2022). J Expo Sci Environ Epidemiol 2023; 33:840-841. [PMID: 37443297 DOI: 10.1038/s41370-023-00571-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/01/2023] [Accepted: 06/12/2023] [Indexed: 07/15/2023]
Affiliation(s)
- Corie A Ellison
- The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH, 45040, USA.
| | - Jon A Arnot
- ARC Arnot Research and Consulting Inc., Toronto, ON, Canada
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Susan P Felter
- The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH, 45040, USA
| | - George P Daston
- The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH, 45040, USA
| | | | - Liisa Toose
- ARC Arnot Research and Consulting Inc., Toronto, ON, Canada
| | | | - Alessandro Sangion
- ARC Arnot Research and Consulting Inc., Toronto, ON, Canada
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | | | - Trevor N Brown
- ARC Arnot Research and Consulting Inc., Toronto, ON, Canada
| | - Li Li
- School of Public Health, University of Nevada Reno, Reno, NV, USA
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3
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Najjar A, Ellison CA, Gregoire S, Hewitt NJ. Correction to: Practical application of the interim internal threshold of toxicological concern (iTTC): a case study based on clinical data. Arch Toxicol 2023; 97:311. [PMID: 36437304 PMCID: PMC9816225 DOI: 10.1007/s00204-022-03398-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Corie A. Ellison
- The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH 45040 USA
| | - Sebastien Gregoire
- L’Oreal Research & Innovation, 1, Avenue Eugène Schueller, 93601 Aulnay-sous-Bois, France
| | - Nicola J. Hewitt
- Cosmetics Europe, Avenue Herrmann-Debroux 40, 1160 Brussels, Belgium
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4
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Najjar A, Ellison CA, Gregoire S, Hewitt NJ. Practical application of the interim internal threshold of toxicological concern (iTTC): a case study based on clinical data. Arch Toxicol 2023; 97:155-164. [PMID: 36149470 PMCID: PMC9816204 DOI: 10.1007/s00204-022-03371-6] [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] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 08/25/2022] [Indexed: 01/19/2023]
Abstract
We present a case study that provides a practical step-by-step example of how the internal Threshold of Toxicological Concern (iTTC) can be used as a tool to refine a TTC-based assessment for dermal exposures to consumer products. The case study uses a theoretical scenario where there are no systemic toxicity data for the case study chemicals (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, octinoxate, and ecamsule). Human dermal pharmacokinetic data following single and repeat dermal exposure to products containing the case study chemicals were obtained from data published by the US FDA. The clinical studies utilized an application procedure that followed maximal use conditions (product applied as 2 mg/cm2 to 75% of the body surface area, 4 times a day). The case study chemicals were first reviewed to determine if they were in the applicability domain of the iTTC, and then, the human plasma concentrations were compared to an iTTC limit of 1 µM. When assessed under maximum usage, the external exposure of all chemicals exceeded the external dose TTC limits. By contrast, the internal exposure to all chemicals, except oxybenzone, was an order of magnitude lower than the 1 µM interim iTTC threshold. This work highlights the importance of understanding internal exposure relative to external dose and how the iTTC can be a valuable tool for assessing low-level internal exposures; additionally, the work demonstrates how to use an iTTC, and highlights considerations and refinement opportunities for the approach.
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Affiliation(s)
| | - Corie A Ellison
- The Procter & Gamble Company, 8700 Mason Montgomery Road, Cincinnati, OH, 45040, USA.
| | - Sebastien Gregoire
- L'Oreal Research & Innovation, 1, Avenue Eugène Schueller, 93601, Aulnay-sous-Bois, France
| | - Nicola J Hewitt
- Cosmetics Europe, Avenue Herrmann-Debroux 40, 1160, Brussels, Belgium
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Obringer C, Lester C, Karb M, Smith A, Ellison CA. Impact of chemical structure on the in vitro hydrolysis of fatty esters of 2-ethylhexanoic acid or 2-ethylhexanol and extrapolation to the in vivo situation. Regul Toxicol Pharmacol 2022; 137:105315. [PMID: 36494001 DOI: 10.1016/j.yrtph.2022.105315] [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: 09/09/2022] [Revised: 11/22/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Fatty esters of 2-ethylhexanoic acid (EHA) and 2-ethylhexanol (EH) are commonly used in cosmetics. Human liver and skin S9 and human plasma were used to determine the in vitro rates of clearance (CLint) of a series of compounds, with a range of 2-11 carbons on the acid or alcohol moiety and branching at the C2 position. The impact of carbon chain length on in vitro CLint was most prominent for the liver metabolism of esters of EH, while for in vitro skin metabolism it was greater for esters of EHA. The position of the branching also impacted the liver hydrolysis rates, especially for the C3, C4, and C5 esters with lower CLint in vitro rates for esters of EHA relative to those of EH. When the in vitro intrinsic clearance rates were scaled to in vivo rates of hepatic clearance, all compounds approximated the rate for hepatic blood flow, mitigating this dependence of metabolism on structure. This work shows how structural changes to the molecule can affect in vitro metabolism and, furthermore, allows for an estimation of the in vivo metabolism.
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Affiliation(s)
- Cindy Obringer
- The Procter & Gamble Company, Cincinnati, OH, 45040, USA
| | - Cathy Lester
- The Procter & Gamble Company, Cincinnati, OH, 45040, USA
| | - Michael Karb
- The Procter & Gamble Company, Cincinnati, OH, 45040, USA
| | - Alex Smith
- The Procter & Gamble Company, Cincinnati, OH, 45040, USA
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Ellison CA, Api AM, Becker RA, Efremenko AY, Gadhia S, Hack CE, Hewitt NJ, Varcin M, Schepky A. Internal Threshold of Toxicological Concern (iTTC): Where We Are Today and What Is Possible in the Near Future. Front Toxicol 2021; 2:621541. [PMID: 35296119 PMCID: PMC8915896 DOI: 10.3389/ftox.2020.621541] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 10/26/2020] [Accepted: 12/18/2020] [Indexed: 11/30/2022] Open
Abstract
The Threshold of Toxicological Concern (TTC) is a risk assessment tool for evaluating low-level exposure to chemicals with limited toxicological data. A next step in the ongoing development of TTC is to extend this concept further so that it can be applied to internal exposures. This refinement of TTC based on plasma concentrations, referred to as internal TTC (iTTC), attempts to convert the chemical-specific external NOAELs (in mg/kg/day) in the TTC database to an estimated internal exposure. A multi-stakeholder collaboration formed, with the aim of establishing an iTTC suitable for human safety risk assessment. Here, we discuss the advances and future directions for the iTTC project, including: (1) results from the systematic literature search for metabolism and pharmacokinetic data for the 1,251 chemicals in the iTTC database; (2) selection of ~350 chemicals that will be included in the final iTTC; (3) an overview of the in vitro caco-2 and in vitro hepatic metabolism studies currently being generated for the iTTC chemicals; (4) demonstrate how PBPK modeling is being utilized to convert a chemical-specific external NOAEL to an internal exposure; (5) perspective on the next steps in the iTTC project.
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Affiliation(s)
- Corie A Ellison
- The Procter and Gamble Company, Cincinnati, OH, United States
| | - Anne Marie Api
- Research Institute for Fragrance Materials, Woodcliff Lake, NJ, United States
| | | | - Alina Y Efremenko
- ScitoVation, Limited Liability Company (LLC), Durham, NC, United States
| | - Sanket Gadhia
- Research Institute for Fragrance Materials, Woodcliff Lake, NJ, United States
| | - C Eric Hack
- ScitoVation, Limited Liability Company (LLC), Durham, NC, United States
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7
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Ellison CA, Tankersley KO, Obringer CM, Carr GJ, Manwaring J, Rothe H, Duplan H, Géniès C, Grégoire S, Hewitt NJ, Jamin CJ, Klaric M, Lange D, Rolaki A, Schepky A. Partition coefficient and diffusion coefficient determinations of 50 compounds in human intact skin, isolated skin layers and isolated stratum corneum lipids. Toxicol In Vitro 2020; 69:104990. [DOI: 10.1016/j.tiv.2020.104990] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/18/2020] [Accepted: 08/27/2020] [Indexed: 11/24/2022]
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8
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Ellison CA, Wu S. Application of structural and functional pharmacokinetic analogs for physiologically based pharmacokinetic model development and evaluation. Regul Toxicol Pharmacol 2020; 114:104667. [DOI: 10.1016/j.yrtph.2020.104667] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/09/2020] [Accepted: 04/17/2020] [Indexed: 12/20/2022]
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Ellison CA, Blackburn KL, Carmichael PL, Clewell HJ, Cronin MTD, Desprez B, Escher SE, Ferguson SS, Grégoire S, Hewitt NJ, Hollnagel HM, Klaric M, Patel A, Salhi S, Schepky A, Schmitt BG, Wambaugh JF, Worth A. Challenges in working towards an internal threshold of toxicological concern (iTTC) for use in the safety assessment of cosmetics: Discussions from the Cosmetics Europe iTTC Working Group workshop. Regul Toxicol Pharmacol 2019; 103:63-72. [PMID: 30653989 PMCID: PMC6644721 DOI: 10.1016/j.yrtph.2019.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/02/2019] [Accepted: 01/07/2019] [Indexed: 11/22/2022]
Abstract
The Threshold of Toxicological Concern (TTC) is an important risk assessment tool which establishes acceptable low-level exposure values to be applied to chemicals with limited toxicological data. One of the logical next steps in the continued evolution of TTC is to develop this concept further so that it is representative of internal exposures (TTC based on plasma concentration). An internal TTC (iTTC) would provide threshold values that could be utilized in exposure-based safety assessments. As part of a Cosmetics Europe (CosEu) research program, CosEu has initiated a project that is working towards the development of iTTCs that can be used for the human safety assessment. Knowing that the development of an iTTC is an ambitious and broad-spanning topic, CosEu organized a Working Group comprised a balance of multiple stakeholders (cosmetics and chemical industries, the EPA and JRC and academia) with relevant experience and expertise and workshop to critically evaluate the requirements to establish an iTTC. Outcomes from the workshop included an evaluation on the current state of the science for iTTC, the overall iTTC strategy, selection of chemical databases, capture and curation of chemical information, ADME and repeat dose data, expected challenges, as well as next steps and ongoing work.
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Affiliation(s)
- Corie A Ellison
- The Procter & Gamble Company, Cincinnati, OH, United States.
| | | | - Paul L Carmichael
- Unilever Safety and Environmental Assurance Center, Bedfordshire, UK
| | | | - Mark T D Cronin
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, England, UK
| | | | - Sylvia E Escher
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany
| | - Steve S Ferguson
- National Institute of Environmental Health Sciences, North Carolina, United States
| | | | | | | | | | - Atish Patel
- Research Institute for Fragrance Materials, New Jersey, United States
| | | | | | | | - John F Wambaugh
- United States Environmental Protection Agency, National Center for Computational Toxicology, North Carolina, United States
| | - Andrew Worth
- European Commission, Joint Research Centre, Ispra, Italy
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10
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Ellison CA. Structural and functional pharmacokinetic analogs for physiologically based pharmacokinetic (PBPK) model evaluation. Regul Toxicol Pharmacol 2018; 99:61-77. [DOI: 10.1016/j.yrtph.2018.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/05/2018] [Accepted: 09/06/2018] [Indexed: 10/28/2022]
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11
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Gartner JG, Durston MM, Booth SA, Ellison CA. Systemic Treatment with a miR-146a Mimic Suppresses Endotoxin Sensitivity and Partially Protects Mice from the Progression of Acute Graft-versus-Host Disease. Scand J Immunol 2017; 86:368-376. [PMID: 28853768 DOI: 10.1111/sji.12597] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 08/21/2017] [Indexed: 11/30/2022]
Abstract
Acute GVHD (aGVHD) is driven by interactions between the allogenic T cell response, inflammation, tissue injury and microbial products that enter the circulation when protective barriers such as the intestinal epithelium become compromised. Mice with aGVHD become hypersensitive to LPS, secreting large quantities of inflammatory mediators that exacerbate tissue injury. We hypothesized that microRNA (miR) modulators could be used in vivo to mitigate LPS hypersensitivity, altering the course of aGVHD. Using the C57BL/6 → (C57BL/6 × DBA/2)F1 -hybrid model of aGVHD, we measured intestinal permeability over time and used a qPCR array to detect concomitant changes in the expression levels of certain microRNAs (miRs) in the intestine. Large increases in permeability were seen on day 15, when endotoxemia becomes detectable and GVHD-associated histopathological lesions develop. Amongst the miRs with altered expression levels were some that regulate sensitivity to endotoxin. We chose to focus on miR-146a and treated recipient mice systemically with a miR-146a mimic early in the GVH reaction. This led to a reduction in the burst of IFNγ that likely plays a priming role in the mechanism underlying heightened sensitivity to endotoxin. LPS-induced TNFα release and GVHD-associated weight loss were also diminished and survival was prolonged. In summary, systemic treatment with a miR-146a mimic dampens the heightened sensitivity to LPS that occurs concomitantly with increased intestinal permeability and provides partial protection from the progression of acute GVHD.
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Affiliation(s)
- J G Gartner
- Department of Pathology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.,Department of Immunology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - M M Durston
- Department of Pathology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - S A Booth
- Molecular PathoBiology, National Microbiology Laboratory, Canadian Science Centre for Human and Animal Health, Public Health Agency of Canada, Winnipeg, MB, Canada.,Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - C A Ellison
- Department of Pathology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.,Department of Immunology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
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Ellison CA, Sawadogo A, Braman S, Nacro S. First Report of Colletotrichum truncatum Causing Stem Cankers on Jatropha curcas in Burkina Faso. Plant Dis 2015; 99:14-20. [PMID: 30699749 DOI: 10.1094/pdis-02-14-0181-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A new disease was identified on the biofuel crop Jatropha curcas in 2012 in Burkina Faso that is causing serious yield losses. The disease was found to be widespread in both Sissili and Comoé Provinces. It causes characteristic leaf lesions, fruit necrosis, and cankers on young stems and branches. There was evidence of multiple infections on plants over the growing season, with regrowth evident from below old cankers, but there was little fruit production from infected branches. A detailed monitoring and assessment was undertaken of the disease progress in a severely infected field, over a 7-week period. The disease symptoms progressed from chlorosis through a necrotic phase and, in approximately 83% of replicates, stem cankers developed that resulted in dieback and lodging of branches. Colletotrichum truncatum and a member of the species complex C. gloeosporioides sensu lato were consistently isolated from fresh stem samples showing early symptoms (chlorosis). Koch's postulates were undertaken, to establish the pathogenicity of the two species. No symptoms were observed on plants inoculated with C. gloeosporioides; however, leaf and stem lesions developed after inoculation with C. truncatum, which was reisolated from the diseased tissue, confirming it as the disease-causing agent. Preliminary management practices for the disease are proposed.
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Affiliation(s)
- C A Ellison
- CABI Europe-UK, Bakeham Lane, Egham, Surrey, TW20 9TY, UK
| | - A Sawadogo
- Faso Biocarburant Fondation, Leo, Sissili, Burkina Faso
| | - S Braman
- Association pour la Promotion du Jatropha et des Energies Renouvelables (APROJER) Banfora, Comoé, Burkina Faso
| | - S Nacro
- Faso Biocarburant Fondation, Leo, Sissili, Burkina Faso
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Erdmann RB, Gartner JG, Leonard WJ, Ellison CA. Lack of functional TSLP receptors mitigates Th2 polarization and the establishment and growth of 4T1 primary breast tumours but has different effects on tumour quantities in the lung and brain. Scand J Immunol 2014; 78:408-18. [PMID: 24033709 DOI: 10.1111/sji.12106] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 08/22/2013] [Indexed: 02/03/2023]
Abstract
The 4T1 mammary carcinoma cell line produces TSLP. We had hypothesized that TSLP promotes the development of a permissive environment for the growth and metastasis of primary tumour and that this is associated with a Th2-polarized antitumour immune response. We found that, in Tslpr(-/-) mice, the mean tumour diameters were smaller from days 27 to 40, and relatively fewer tumour cells were present in the lung, compared with wild-type mice. Polarization of the Th2 cytokine profile was also diminished in Tslpr(-/-) mice. These findings confirmed those reported previously by others. Here, we further show that primary tumours are established less often in Tslpr(-/-) mice and that, unexpectedly, the relative number of tumour cells in the brain is greater in Tslpr(-/-) mice compared with wild-type mice. Findings from our cytotoxicity assays show that 4T1-directed lysis is undetectable in both WT and Tslpr(-/-) mice, ruling out the possibility that altered cytotoxic responses in Tslpr(-/-) mice are responsible for the differences we observed. In a human tissue microarray, positive staining for TSLP was seen in tumour cells from breast cancer tissue, but it was also seen in normal glandular epithelial cells from normal breast tissue, which has not been shown before. Thus, our findings provide new insight into the effects of TSLP in metastatic breast cancer.
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Affiliation(s)
- R B Erdmann
- Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada
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14
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Dadson OA, Ellison CA, Singleton ST, Chi LH, McGarrigle BP, Lein PJ, Farahat FM, Farahat T, Olson JR. Metabolism of profenofos to 4-bromo-2-chlorophenol, a specific and sensitive exposure biomarker. Toxicology 2013; 306:35-9. [PMID: 23415833 DOI: 10.1016/j.tox.2013.01.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 01/23/2013] [Accepted: 01/29/2013] [Indexed: 11/28/2022]
Abstract
Profenofos is a direct acting phosphorothioate organophosphorus (OP) pesticide capable of inhibiting β-esterases such as acetylcholinesterase, butyrylcholinesterase, and carboxylesterase. Profenofos is known to be detoxified to the biologically inactive metabolite, 4-bromo-2-chlorophenol (BCP); however, limited data are available regarding the use of urinary BCP as an exposure biomarker in humans. A pilot study conducted in Egyptian agriculture workers, demonstrated that urinary BCP levels prior to application (3.3-30.0 μg/g creatinine) were elevated to 34.5-3,566 μg/g creatinine during the time workers were applying profenofos to cotton fields. Subsequently, the in vitro enzymatic formation of BCP was examined using pooled human liver microsomes and recombinant human cytochrome P-450s (CYPs) incubated with profenofos. Of the nine human CYPs studied, only CYPs 3A4, 2B6, and 2C19 were able to metabolize profenofos to BCP. Kinetic studies indicated that CYP 2C19 has the lowest Km, 0.516 μM followed by 2B6 (Km=1.02 μM) and 3A4 (Km=18.9μM). The Vmax for BCP formation was 47.9, 25.1, and 19.2 nmol/min/nmol CYP for CYP2B6, 2C19, and 3A4, respectively. Intrinsic clearance (Vmax/Km) values of 48.8, 46.9, and 1.02 ml/min/nmol CYP 2C19, 2B6, and 3A4, respectively, indicate that CYP2C19 and CYP2B6 are primarily responsible for the detoxification of profenofos. These findings support the use of urinary BCP as a biomarker of exposure to profenofos in humans and suggest polymorphisms in CYP 2C19 and CYP 2B6 as potential biomarkers of susceptibility.
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Affiliation(s)
- Oswald A Dadson
- Department of Pharmacology & Toxicology, State University of New York at Buffalo, Buffalo, NY, USA
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Ellison CA, Crane AL, Bonner MR, Knaak JB, Browne RW, Lein PJ, Olson JR. PON1 status does not influence cholinesterase activity in Egyptian agricultural workers exposed to chlorpyrifos. Toxicol Appl Pharmacol 2012; 265:308-15. [PMID: 22975224 DOI: 10.1016/j.taap.2012.08.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2012] [Revised: 08/28/2012] [Accepted: 08/29/2012] [Indexed: 11/25/2022]
Abstract
Animal studies have shown that paraoxonase 1 (PON1) genotype can influence susceptibility to the organophosphorus pesticide chlorpyrifos (CPF). However, Monte Carlo analysis suggests that PON1 genotype may not affect CPF-related toxicity at low exposure conditions in humans. The current study sought to determine the influence of PON1 genotype on the activity of blood cholinesterase as well as the effect of CPF exposure on serum PON1 in workers occupationally exposed to CPF. Saliva, blood and urine were collected from agricultural workers (n=120) from Egypt's Menoufia Governorate to determine PON1 genotype, blood cholinesterase activity, serum PON1 activity towards chlorpyrifos-oxon (CPOase) and paraoxon (POase), and urinary levels of the CPF metabolite 3,5,6-trichloro-2-pyridinol (TCPy). The PON1 55 (P≤0.05) but not the PON1 192 genotype had a significant effect on CPOase activity. However, both the PON1 55 (P≤0.05) and PON1 192 (P≤0.001) genotypes had a significant effect on POase activity. Workers had significantly inhibited AChE and BuChE after CPF application; however, neither CPOase activity nor POase activity was associated with ChE depression when adjusted for CPF exposure (as determined by urinary TCPy levels) and stratified by PON1 genotype. CPOase and POase activity were also generally unaffected by CPF exposure although there were alterations in activity within specific genotype groups. Together, these results suggest that workers retained the capacity to detoxify chlorpyrifos-oxon under the exposure conditions experienced by this study population regardless of PON1 genotype and activity and that effects of CPF exposure on PON1 activity are minimal.
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Affiliation(s)
- Corie A Ellison
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
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Ellison CA, Abou El-Ella SS, Tawfik M, Lein PJ, Olson JR. Allele and genotype frequencies of CYP2B6 and CYP2C19 polymorphisms in Egyptian agricultural workers. J Toxicol Environ Health A 2012; 75:232-241. [PMID: 22352331 PMCID: PMC3500531 DOI: 10.1080/15287394.2012.641201] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Genetic variability in cytochrome P-450 (CYP) has the potential to modify pharmacological and toxicological responses to many chemicals. Both CYP2B6 and CYP2C19 are pharmacologically and toxicologically relevant due to their ability to metabolize multiple drugs and environmental contaminants, including the organophosphorus (OP) pesticide chlorpyrifos. The aim of this study was to determine the prevalence of CYP2B6 and CYP2C19 variants in an indigenous Egyptian population (n = 120) that was shown to be occupationally exposed to chlorpyrifos. Further, the genotyping data was compared for Egyptians with previously studied populations to determine between population differences. Allelic frequencies were CYP2B6 1459C > T (3.8%), CYP2B6 785A > G (30.4%), CYP2B6 516G > T (28.8%), CYP2C19 681G > A (3.8%), and CYP2C19 431G > A (0%). The most prevalent CYP2B6 genotype combinations were CYP2B6 *1/*1 (44%), *1/*6 (38%), *6/*6 (8%), and *1/*5 (6%). The frequency of the CYP2C19 genotype combinations were CYP2C19 *1/*1 (93%), *1/*2 (6%), and *2/*2 (1%). The frequency of the CYP2B6 516G > T and CYP2B6 785A > G polymorphisms in this Egyptian cohort is similar to that found North American and European populations but significantly different from that reported for West African populations, while that of CYP2B6 1459C > T is similar to that found in Africans and African Americans. The observed frequency of CYP2C19 681G > A in Egyptians is similar to that of African pygmies but significantly different from other world populations, while CYP2C19 431 G > A was significantly different from that of African pygmies but similar to other world populations.
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Affiliation(s)
- Corie A Ellison
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14214, USA.
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Ellison CA, Tian Y, Knaak JB, Kostyniak PJ, Olson JR. Human hepatic cytochrome P450-specific metabolism of the organophosphorus pesticides methyl parathion and diazinon. Drug Metab Dispos 2011; 40:1-5. [PMID: 21969518 DOI: 10.1124/dmd.111.042572] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Organophosphorus pesticides (OPs) are a public health concern due to their worldwide use and documented human exposures. Phosphorothioate OPs are metabolized by cytochrome P450s (P450s) through either a dearylation reaction to form an inactive metabolite, or through a desulfuration reaction to form an active oxon metabolite, which is a potent cholinesterase inhibitor. This study investigated the rate of desulfuration (activation) and dearylation (detoxification) of methyl parathion and diazinon in human liver microsomes. In addition, recombinant human P450s were used to determine the P450-specific kinetic parameters (K(m) and V(max)) for each compound for future use in refining human physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models of OP exposure. The primary enzymes involved in bioactivation of methyl parathion were CYP2B6 (K(m) = 1.25 μM; V(max) = 9.78 nmol · min(-1) · nmol P450(-1)), CYP2C19 (K(m) = 1.03 μM; V(max) = 4.67 nmol · min(-1) · nmol P450(-1)), and CYP1A2 (K(m) = 1.96 μM; V(max) = 5.14 nmol · min(-1) · nmol P450(-1)), and the bioactivation of diazinon was mediated primarily by CYP1A1 (K(m) = 3.05 μM; V(max) = 2.35 nmol · min(-1) · nmol P450(-1)), CYP2C19 (K(m) = 7.74 μM; V(max) = 4.14 nmol · min(-1) · nmol P450(-1)), and CYP2B6 (K(m) = 14.83 μM; V(max) = 5.44 nmol · min(-1) · nmol P450(-1)). P450-mediated detoxification of methyl parathion only occurred to a limited extent with CYP1A2 (K(m) = 16.8 μM; V(max) = 1.38 nmol · min(-1) · nmol P450(-1)) and 3A4 (K(m) = 104 μM; V(max) = 5.15 nmol · min(-1) · nmol P450(-1)), whereas the major enzyme involved in diazinon detoxification was CYP2C19 (K(m) = 5.04 μM; V(max) = 5.58 nmol · min(-1) · nmol P450(-1)). The OP- and P450-specific kinetic values will be helpful for future use in refining human PBPK/PD models of OP exposure.
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Affiliation(s)
- Corie A Ellison
- University at Buffalo, Department of Pharmacology and Toxicology, 3435 Main Street, Buffalo, NY 14214, USA
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Ellison CA, Smith JN, Lein PJ, Olson JR. Pharmacokinetics and pharmacodynamics of chlorpyrifos in adult male Long-Evans rats following repeated subcutaneous exposure to chlorpyrifos. Toxicology 2011; 287:137-44. [PMID: 21708215 DOI: 10.1016/j.tox.2011.06.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 05/31/2011] [Accepted: 06/11/2011] [Indexed: 01/11/2023]
Abstract
Chlorpyrifos (CPF) is a commonly used organophosphorus pesticide. Several pharmacokinetic and pharmacodynamic studies have been conducted in rats in which CPF was administered as a single bolus dose. However, there is limited data regarding the pharmacokinetics and pharmacodynamics following daily exposure. Since occupational exposures often consist of repeated, daily exposures, there is a need to evaluate the pharmacokinetics and pharmacodynamics of CPF under exposure conditions which more accurately reflect real world human exposures. In this study, the pharmacokinetics and pharmacodynamics of CPF were assessed in male Long-Evans rats exposed daily to CPF (0, 3 or 10mg/kg/day, s.c. in peanut oil) over a 10 day study period. Throughout the study, multiple pharmacokinetic (urinary TCPy levels and tissue CPF and metabolite levels) and pharmacodynamic (blood and brain AChE activity) determinants were measured. Average blood AChE activity on day 10 was 54% and 33% of baseline among animals in the 3 and 10mg/kg/day CPF treatment groups, respectively, while average brain AChE activity was 67% and 28% of baseline. Comparable dose-response relationships between brain AChE inhibition and blood AChE inhibition, suggests that blood AChE activity is a valid biomarker of brain AChE activity. The pharmacokinetic and pharmacodynamic measures collected in this study were also used to optimize a rat physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model for multiple s.c. exposures to CPF based on a previously published rat PBPK/PD model for CPF following a single bolus injection. This optimized model will be useful for determining pharmacokinetic and pharmacodynamic responses over a wide range of doses and durations of exposure, which will improve extrapolation of results between rats and humans.
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Affiliation(s)
- Corie A Ellison
- Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, NY 14214, USA.
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Farahat FM, Ellison CA, Bonner MR, McGarrigle BP, Crane AL, Fenske RA, Lasarev MR, Rohlman DS, Anger WK, Lein PJ, Olson JR. Biomarkers of chlorpyrifos exposure and effect in Egyptian cotton field workers. Environ Health Perspect 2011; 119:801-6. [PMID: 21224175 PMCID: PMC3114814 DOI: 10.1289/ehp.1002873] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 01/11/2011] [Indexed: 05/22/2023]
Abstract
BACKGROUND Chlorpyrifos (CPF), a widely used organophosphorus pesticide (OP), is metabolized to CPF-oxon, a potent cholinesterase (ChE) inhibitor, and trichloro-2-pyridinol (TCPy). Urinary TCPy is often used as a biomarker for CPF exposure, whereas blood ChE activity is considered an indicator of CPF toxicity. However, whether these biomarkers are dose related has not been studied extensively in populations with repeated daily OP exposures. OBJECTIVE We sought to determine the relationship between blood ChE and urinary TCPy during repeated occupational exposures to CPF. METHODS Daily urine samples and weekly blood samples were collected from pesticide workers (n=38) in Menoufia Governorate, Egypt, before, during, and after 9-17 consecutive days of CPF application to cotton fields. We compared blood butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) activities with the respective urinary TCPy concentrations in each worker. RESULTS Average TCPy levels during the middle of a 1- to 2-week CPF application period were significantly higher in pesticide applicators (6,437 µg/g creatinine) than in technicians (184 µg/g) and engineers (157 µg/g), both of whom are involved in supervising the application process. We observed a statistically significant inverse correlation between urinary TCPy and blood BuChE and AChE activities. The no-effect level (or inflection point) of the exposure-effect relationships has an average urinary TCPy level of 114 µg/g creatinine for BuChE and 3,161 µg/g creatinine for AChE. CONCLUSIONS Our findings demonstrate a dose-effect relationship between urinary TCPy and both plasma BuChE and red blood cell AChE in humans exposed occupationally to CPF. These findings will contribute to future risk assessment efforts for CPF exposure.
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Affiliation(s)
- Fayssal M. Farahat
- Department of Community Medicine and Public Health, Faculty of Medicine, Menoufia University, Shebin El-Kom, Egypt
| | | | - Matthew R. Bonner
- Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, New York, USA
| | | | | | - Richard A. Fenske
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Michael R. Lasarev
- Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, Oregon, USA
| | - Diane S. Rohlman
- Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, Oregon, USA
| | - W. Kent Anger
- Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, Oregon, USA
| | - Pamela J. Lein
- Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, Oregon, USA
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, California, USA
| | - James R. Olson
- Department of Pharmacology and Toxicology and
- Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, New York, USA
- Address correspondence to J.R. Olson, University at Buffalo, Department of Pharmacology and Toxicology, 3435 Main St., 102 Farber Hall, Buffalo, NY 14214 USA. Telephone: (716) 829-2319. Fax: (716) 829-2801. E-mail:
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Foxenberg RJ, Ellison CA, Knaak JB, Ma C, Olson JR. Cytochrome P450-specific human PBPK/PD models for the organophosphorus pesticides: chlorpyrifos and parathion. Toxicology 2011; 285:57-66. [PMID: 21514354 DOI: 10.1016/j.tox.2011.04.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 03/30/2011] [Accepted: 04/05/2011] [Indexed: 10/18/2022]
Abstract
Organophosphorus pesticides (OPs) remain a potential concern to human health because of their continuing use worldwide. Phosphororthioate OPs like chlorpyrifos and parathion are directly activated and detoxified by various cytochrome P450s (CYPs), with the primary CYPs involved being CYP2B6 and CYP2C19. The goal of the current study was to convert a previously reported human pharmacokinetic and pharmacodynamic (PBPK/PD) model for chlorpyrifos, that used chlorpyrifos metabolism parameters from rat liver, into a human CYP based/age-specific model using recombinant human CYP kinetic parameters (V(max), K(m)), hepatic CYP content and plasma binding measurements to estimate new values for acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition and to use the model as a template for the development of a comparable parathion PBPK/PD model. The human CYP based/age-specific PBPK/PD models were used to simulate single oral exposures of adults (19 year old) and infants (1 year) to chlorpyrifos (10,000, 1000 and 100 μg/kg) or parathion (100, 25 and 5 μg/kg). Model simulations showed that there is an age dependency in the amount of blood cholinesterase inhibition observed, however additional age-dependent data are needed to further optimize age-specific human PBPK/PD modeling for these OP compounds. PBPK/PD model simulations estimated that a 4-fold increase or decrease in relative CYP2B6 and CYP2C19 content would produce a 9-22% inhibition in blood AChE activity following exposure of an adult to chlorpyrifos (1000 μg/kg). Similar model simulation produced an 18-22% inhibition in blood AChE activity following exposure of an adult to parathion (25 μg/kg). Individuals with greater CYP2B6 content and lower CYP2C19 content were predicted to be most sensitive to both OPs. Changes in hepatic CYP2B6 and CYP2C19 content had more of an influence on cholinesterase inhibition for exposures to chlorpyrifos than parathion, which agrees with previously reported literature that these CYPs are more reaction biased for desulfurization (activation) and dearylation (detoxification) of chlorpyrifos compared to parathion. The data presented here illustrate how PBPK/PD models with human enzyme-specific parameters can assist ongoing risk assessment efforts and aid in the identification of sensitive individuals and populations.
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Affiliation(s)
- Robert J Foxenberg
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA
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Ovando BJ, Ellison CA, Vezina CM, Olson JR. Toxicogenomic analysis of exposure to TCDD, PCB126 and PCB153: identification of genomic biomarkers of exposure to AhR ligands. BMC Genomics 2010; 11:583. [PMID: 20959002 PMCID: PMC3091730 DOI: 10.1186/1471-2164-11-583] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [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: 06/10/2010] [Accepted: 10/19/2010] [Indexed: 02/10/2023] Open
Abstract
Background Two year cancer bioassays conducted by the National Toxicology Program have shown chronic exposure to dioxin-like compounds (DLCs) to lead to the development of both neoplastic and non-neoplastic lesions in the hepatic tissue of female Sprague Dawley rats. Most, if not all, of the hepatotoxic effects induced by DLC's are believed to involve the binding and activation of the transcription factor, the aryl hydrocarbon receptor (AhR). Toxicogenomics was implemented to identify genomic responses that may be contributing to the development of hepatotoxicity in rats. Results Through comparative analysis of time-course microarray data, unique hepatic gene expression signatures were identified for the DLCs, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (100 ng/kg/day) and 3,3',4,4',5-pentachlorobiphenyl (PCB126) (1000 ng/kg/day) and the non-DLC 2,2',4,4',5,5',-hexachlorobiphenyl (PCB153) (1000 μg/kg/day). A common time independent signature of 41 AhR genomic biomarkers was identified which exhibited at least a 2-fold change in expression following subchronic (13-wk) and chronic (52-wk) p.o. exposure to TCDD and PCB126, but not the non DLC, PCB153. Real time qPCR analysis validated that 30 of these genes also exhibited at least a 2-fold change in hepatic expression at 24 hr following a single exposure to TCDD (5 μg/kg, po). Phenotypic anchoring was conducted which identified forty-six genes that were differently expressed both following chronic p.o. exposure to DLCs and in previously reported studies of cholangiocarcinoma or hepatocellular adenoma. Conclusions Together these analyses provide a comprehensive description of the genomic responses which occur in rat hepatic tissue with exposure to AhR ligands and will help to isolate those genomic responses which are contributing to the hepatotoxicity observed with exposure to DLCs. In addition, the time independent gene expression signature of the AhR ligands may assist in identifying other agents with the potential to elicit dioxin-like hepatotoxic responses.
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Affiliation(s)
- Bladimir J Ovando
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14214, USA
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Abstract
Our previous work using a C57BL/6-->(C57BL/6 x DBA/2)F1-hybrid model of acute GVHD showed that mortality can be completely prevented if grafts are depleted of NK1.1+ cells in vitro. To achieve this protection, it was necessary to inject the donors with polyinosinic:polycytidylic acid 18 h before the graft was harvested. In another study, we showed that interferon (IFN)-gamma production and lipopolysaccharide (LPS)-induced tumour necrosis factor (TNF)-alpha release are markedly reduced in these recipients, suggesting that this treatment abrogates the Th1-mediated immune response that underlies the development of this disease. However, because it has also been hypothesized that cytotoxic NK1.1+ cells mediate injury to tissues targeted by the GVH reaction, we wished to determine whether NK1.1 depletion of the graft would also prevent the development of GVHD-associated enteropathy and endotoxemia. We therefore induced GVH reactions in (C57BL/6 x DBA/2)F1 hybrids using either untreated grafts from unstimulated C57BL/6 donors, or NK1.1-depleted grafts from poly I:C-stimulated donors. We identified intestinal lesions morphologically in sections of ileum collected from each group of recipients but not in control mice. We also compared endotoxin levels in the sera. Our results indicate that GVHD-associated enteropathy occurs in both groups of recipients, and that the levels of LPS in the sera do not differ significantly.
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MESH Headings
- Animals
- Antigens/immunology
- Antigens, Ly
- Antigens, Surface
- Cell Transplantation
- Cytotoxicity, Immunologic
- Endotoxemia/blood
- Endotoxemia/immunology
- Female
- Graft vs Host Disease/blood
- Graft vs Host Disease/immunology
- Graft vs Host Disease/mortality
- Graft vs Host Disease/pathology
- Ileum/immunology
- Ileum/pathology
- Intestinal Mucosa/pathology
- Killer Cells, Natural/immunology
- Lectins, C-Type
- Lipopolysaccharides/blood
- Lymph Nodes/cytology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Inbred DBA
- NK Cell Lectin-Like Receptor Subfamily B
- Proteins/immunology
- Tumor Cells, Cultured
- Weight Loss
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Affiliation(s)
- C A Ellison
- Department of Pathology, University of Manitoba, Winnipeg, Manitoba, Canada
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Ellison CA, HayGlass KT, Fischer JM, Rector ES, MacDonald GC, Gartner JG. Depletion of natural killer cells from the graft reduces interferon-gamma levels and lipopolysaccharide-induced tumor necrosis factor-alpha release in F1 hybrid mice with acute graft-versus-host disease. Transplantation 1998; 66:284-94. [PMID: 9721794 DOI: 10.1097/00007890-199808150-00002] [Citation(s) in RCA: 14] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND We wished to determine whether removal of NK1.1+ cells from the graft provides protection against acute graft-versus-host disease (GVHD) by obviating the Th1 immune response that underlies the development of this disease. METHODS Graft-versus-host (GVH) reactions were induced in two groups of (C57BL/6 x DBA/2)F1 hybrid mice. The first received grafts harvested from polyinosinic:polycytidylic acid-stimulated, C57BL/6 donors and depleted in vitro of NK1.1+ cells. This treatment provides protection against GVHD-associated mortality and cachexia. The second received unmodified grafts. We compared interferon-gamma and interleukin-10 production as well as the levels of engraftment in these two groups. Lipopolysaccharide-induced tumor necrosis factor-alpha (TNF-alpha) release was also compared since TNF-alpha levels in GVH mice following injection of a sublethal dose of endotoxin provide an index of macrophage priming by Th1 cytokines. RESULTS Interferon-gamma production was absent in recipients of NK1.1-depleted grafts at the time when high levels were seen in recipients of unmodified grafts. Following lipopolysaccharide injection, high levels of TNF-alpha were observed in recipients of unmodified grafts, whereas negligible amounts were present in recipients of NK1.1-depleted grafts. The use of NK1.1-depleted grafts did not result in a reduced level of engraftment of CD4+ or CD8+ cells. CONCLUSIONS These results suggest that NK1.1 depletion of the graft confers protection against mortality by interfering with an immunoregulatory mechanism that results in the development of a Th1 response in GVH mice, and does not result in abortion of the graft. Because macrophage priming is prevented, recipients are also protected from the exaggerated sensitivity to endotoxin seen in mice with acute GVHD.
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Affiliation(s)
- C A Ellison
- Department of Pathology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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Ellison CA, Fischer JM, HayGlass KT, Gartner JG. Murine graft-versus-host disease in an F1-hybrid model using IFN-gamma gene knockout donors. J Immunol 1998; 161:631-40. [PMID: 9670937] [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] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
These experiments were performed to determine whether the absence of donor-derived IFN-gamma would influence the outcome of acute graft-vs-host disease (GVHD). Graft-vs-host reactions were induced in B6D2F1 hybrids using grafts from either IFN-gamma gene knockout (gko) or wild-type, C57BL/6J, parental strain donors. GVHD was equally lethal in both groups, but IFN-gamma gko graft recipients developed a more protracted form of the disease. These mice developed early wasting that persisted until death. IFN-gamma was present in spleen cell cultures from wild-type graft recipients, but was absent in cultures from IFN-gamma gko graft recipients. Both recipient groups showed macrophage priming for LPS-induced TNF-alpha release. Engraftment of donor-derived CD4+ and CD8+ cells was greater in IFN-gamma gko graft recipients. Pathologic changes in IFN-gamma gko graft recipients were different from those typically seen in acute GVHD. The syndrome developing in IFN-gamma gko recipients consisted of patchy alopecia, corneal dryness and clouding, and lymphocytic infiltration of the liver, pancreas, salivary gland, lung, and kidney. Lymphocytic infiltrates were also present in the epidermis and the epithelium of both bile and salivary gland ducts. Some of the lesions closely resembled those seen in the "sicca"/Sjogren's-like syndrome associated with chronic GVHD; however, there was no evidence of immune complex deposition in the kidney. These results indicate that GVHD in IFN-gamma gko graft recipients shares many features with acute GVHD, but both the duration of the disease and its pathologic manifestations are different. Our results suggest that IFN-gamma plays a significant role in the pathogenesis of acute GVHD by increasing the rate at which mortality develops.
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Affiliation(s)
- C A Ellison
- Department of Pathology, University of Manitoba, Faculty of Medicine, Winnipeg, Canada
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Wang M, Ellison CA, Gartner JG, HayGlass KT. Natural killer cell depletion fails to influence initial CD4 T cell commitment in vivo in exogenous antigen-stimulated cytokine and antibody responses. J Immunol 1998; 160:1098-105. [PMID: 9570522] [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] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The role played by NK- and NK1.1-expressing T cells in CD4 T cell activation and induction of immune responses in vivo is controversial. These effector cells of the innate immune response are hypothesized to play a pivotal role in shaping initial T cell activation, with some groups reporting that classical NK cells are required for optimal Th1-like T cell activation, and others supporting a role for NK1.1+ alphabeta T cells in Th2 generation. Here, we examine the impact of in vivo NK cell depletion on the development of exogenous Ag-specific cytokine and Ab responses using a murine model of human immediate hypersensitivity. OVA-specific immune responses were induced in 1) C57Bl/6 bg/bg and bg/+ mice, 2) BALB/c mice pretreated with anti-asialoGM1 or control Ab, and 3) C57Bl/6 mice depleted of NK1.1-expressing cells by in vivo administration of anti-NK1.1 mAb PK136. Depletion efficacy was assessed by functional assays and flow cytometric analysis. Each of these approaches indicated that depletion of NK cells and NK1.1+ CD4+ T cells fails to alter the Th1:Th2 balance of Ag-driven cytokine synthesis, as indicated by OVA-stimulated cytokine synthesis in primary bulk culture. Similarly, the kinetics and intensity of effector responses such as OVA-specific IgG2a and IgE synthesis were neither increased nor decreased in any of the three models examined. The results argue that NK cells and peripheral NK1.1+ T cells do not play an essential role in shaping the induction of Ag-specific immune responses to soluble exogenous Ags, the most common class of inhalant allergen.
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Affiliation(s)
- M Wang
- Department of Immunology, University of Manitoba, Winnipeg, Canada
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Ellison CA, MacDonald GC, Rector ES, Gartner JG. Gamma delta T cells in the pathobiology of murine acute graft-versus-host disease. Evidence that gamma delta T cells mediate natural killer-like cytotoxicity in the host and that elimination of these cells from donors significantly reduces mortality. J Immunol 1995; 155:4189-98. [PMID: 7594574] [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] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
NK-like cytotoxicity in F1-hybrid mice with acute GVH disease is mediated by donor-derived CD3+/CD4-/CD8- cells that can lyse both NK-sensitive YAC-1 target cells as well as NK-resistant targets such as BW1100 and P815. Our objective was to determine whether this activity is mediated by gamma delta TCR+ cells. We showed that NK-like cytotoxic activity in the spleen and lymph nodes of mice with acute GVH disease could be depleted by indirect complement-mediated lysis using an Ab against gamma delta TCR. When purified NK1.1+ spleen cells that had been positively selected on a magnetic cell separator were used as effector cells, we found that NK-like cytotoxicity was mediated only by gamma delta TCR+ cells, suggesting that cells with NK-like activity are gamma delta TCR+/NK1.1+. We showed by flow cytometry experiments that coexpression of NK1.1 and TCR-gamma delta occurred on a large proportion of large granular lymphocytes in the spleens of GVH mice, but was not detectable in normal control mice. In GVH mice, fewer than 10% of small agranular NK1.1+ lymphocytes coexpressed NK1.1+ and gamma delta TCR+. On the basis of this hypothesis, we postulate that graft-derived large granular lymphocytes develop the NK1.1+/gamma delta TCR+ phenotype during the reaction, and that these cells play a role in the pathogenesis of acute GVH disease. We performed experiments to determine whether depletion of gamma delta T cells from donor mice affected the outcome of lethal GVH disease and found that there was a significant reduction in mortality.
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MESH Headings
- Acute Disease
- Animals
- Antigens/immunology
- Antigens, Ly
- Antigens, Surface
- Cytotoxicity, Immunologic
- Female
- Flow Cytometry
- Graft vs Host Disease/etiology
- Graft vs Host Disease/mortality
- Graft vs Host Disease/pathology
- Immunophenotyping
- Killer Cells, Natural/immunology
- Lectins, C-Type
- Lymph Nodes/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Inbred DBA
- NK Cell Lectin-Like Receptor Subfamily B
- Proteins/immunology
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Spleen/immunology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/pathology
- T-Lymphocytes, Cytotoxic/transplantation
- Weight Loss/immunology
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Affiliation(s)
- C A Ellison
- Department of Immunology, University of Manitoba, Winnipeg, Canada
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Ellison CA, MacDonald GC, Rector ES, Gartner JG. Gamma delta T cells in the pathobiology of murine acute graft-versus-host disease. Evidence that gamma delta T cells mediate natural killer-like cytotoxicity in the host and that elimination of these cells from donors significantly reduces mortality. The Journal of Immunology 1995. [DOI: 10.4049/jimmunol.155.9.4189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
NK-like cytotoxicity in F1-hybrid mice with acute GVH disease is mediated by donor-derived CD3+/CD4-/CD8- cells that can lyse both NK-sensitive YAC-1 target cells as well as NK-resistant targets such as BW1100 and P815. Our objective was to determine whether this activity is mediated by gamma delta TCR+ cells. We showed that NK-like cytotoxic activity in the spleen and lymph nodes of mice with acute GVH disease could be depleted by indirect complement-mediated lysis using an Ab against gamma delta TCR. When purified NK1.1+ spleen cells that had been positively selected on a magnetic cell separator were used as effector cells, we found that NK-like cytotoxicity was mediated only by gamma delta TCR+ cells, suggesting that cells with NK-like activity are gamma delta TCR+/NK1.1+. We showed by flow cytometry experiments that coexpression of NK1.1 and TCR-gamma delta occurred on a large proportion of large granular lymphocytes in the spleens of GVH mice, but was not detectable in normal control mice. In GVH mice, fewer than 10% of small agranular NK1.1+ lymphocytes coexpressed NK1.1+ and gamma delta TCR+. On the basis of this hypothesis, we postulate that graft-derived large granular lymphocytes develop the NK1.1+/gamma delta TCR+ phenotype during the reaction, and that these cells play a role in the pathogenesis of acute GVH disease. We performed experiments to determine whether depletion of gamma delta T cells from donor mice affected the outcome of lethal GVH disease and found that there was a significant reduction in mortality.
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Affiliation(s)
- C A Ellison
- Department of Immunology, University of Manitoba, Winnipeg, Canada
| | - G C MacDonald
- Department of Immunology, University of Manitoba, Winnipeg, Canada
| | - E S Rector
- Department of Immunology, University of Manitoba, Winnipeg, Canada
| | - J G Gartner
- Department of Immunology, University of Manitoba, Winnipeg, Canada
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Abstract
Natural killer (NK) cells are involved not only in resistance to tumors and infection, but also in some transplantation reactions. A specific, inexpensive method for purifying large numbers of NK cells is often required. All NK cells in H-2b mice express the surface marker NK1.1. We report a method for positively selecting NK1.1+ spleen cells from normal and Poly I:C-stimulated C56Bl/6 mice using a magnetic cell separation technique known as MACS. Our results show that cytotoxic activity directed at YAC-1 target cells by normal and Poly I:C-stimulated spleen cells could be increased five-fold using this method. We also found that spleen cells from mice given Poly I:C could lyse NK-resistant, BW1100 target cells, and that this activity could be increased two-fold. Flow cytometry analysis of Poly I:C-stimulated, MACS enriched, NK1.1+ spleen cells revealed the presence of two subpopulations: one consisting of LGL and the other consisting of smaller, agranular lymphocytes (SAL). After enrichment, the percentage of NK1.1+ spleen cells increased from 69% to 91% in the LGL subpopulation and from 33% to 73% in the SAL subpopulation. These results clearly demonstrate the effectiveness of the MACS technique for purifying large numbers of NK1.1+ cells for both flow cytometric and functional analyses.
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Affiliation(s)
- C A Ellison
- University of Manitoba, Department of Immunology, Winnipeg, Canada
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