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An In Vitro Model of Gastric Inflammation and Treatment with Cobalamin. Int J Inflam 2017; 2017:5968618. [PMID: 28676841 PMCID: PMC5476893 DOI: 10.1155/2017/5968618] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/26/2017] [Accepted: 05/07/2017] [Indexed: 02/04/2023] Open
Abstract
Pernicious anaemia (PA) is an autoimmune condition where antibodies target intrinsic factor and parietal cells, reducing the patient's ability to absorb cobalamin promoting atrophic gastritis. Treatment guidelines are based on excretion data of hydroxocobalamin from healthy individuals obtained 50 years ago. This manuscript describes the use of phorbol 12-myristate 13-acetate (PMA) to stimulate low grade inflammation in an epithelial colorectal cell line to assess the efficacy of methylcobalamin and hydroxocobalamin. Nitric oxide increased significantly in cells exposed to higher doses of PMA (100 ng/ml, 150 ng/ml, and 200 ng/ml) accompanied by a loss of the characteristic cobblestone morphology with no negative effect on cell activity or viability. A significant reduction in nitric oxide production was associated with the addition of 200 pg/ml hydroxocobalamin, alongside a return to the characteristic cobblestone morphology. This study highlights the use of PMA to promote low grade inflammation in human cell lines to model gastric inflammation associated with autoimmunity; furthermore it raises questions regarding the concentration of cobalamin administered clinically to restore cell functionality, feasibly allowing the patient to receive reduced quantity of the vitamin more regularly, providing the patient with levels which are akin to dietary intake.
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Harakal J, Rival C, Qiao H, Tung KS. Regulatory T Cells Control Th2-Dominant Murine Autoimmune Gastritis. THE JOURNAL OF IMMUNOLOGY 2016; 197:27-41. [PMID: 27259856 DOI: 10.4049/jimmunol.1502344] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/18/2016] [Indexed: 12/12/2022]
Abstract
Pernicious anemia and gastric carcinoma are serious sequelae of autoimmune gastritis (AIG). Our study indicates that in adult C57BL/6-DEREG mice expressing a transgenic diphtheria toxin receptor under the Foxp3 promoter, transient regulatory T cell (Treg) depletion results in long-lasting AIG associated with both H(+)K(+)ATPase and intrinsic factor autoantibody responses. Although functional Tregs emerge over time during AIG occurrence, the effector T cells rapidly become less susceptible to Treg-mediated suppression. Whereas previous studies have implicated dysregulated Th1 cell responses in AIG pathogenesis, eosinophils have been detected in gastric biopsy specimens from patients with AIG. Indeed, AIG in DEREG mice is associated with strong Th2 cell responses, including dominant IgG1 autoantibodies, elevated serum IgE, increased Th2 cytokine production, and eosinophil infiltration in the stomach-draining lymph nodes. In addition, the stomachs exhibit severe mucosal and muscular hypertrophy, parietal cell loss, mucinous epithelial cell metaplasia, and massive eosinophilic inflammation. Notably, the Th2 responses and gastritis severity are significantly ameliorated in IL-4- or eosinophil-deficient mice. Furthermore, expansion of both Th2-promoting IFN regulatory factor 4(+) programmed death ligand 2(+) dendritic cells and ILT3(+) rebounded Tregs was detected after transient Treg depletion. Collectively, these data suggest that Tregs maintain physiological tolerance to clinically relevant gastric autoantigens, and Th2 responses can be a pathogenic mechanism in AIG.
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Affiliation(s)
- Jessica Harakal
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908; Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908; and
| | - Claudia Rival
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908; Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908; and Department of Pathology, University of Virginia, Charlottesville, VA 22908
| | - Hui Qiao
- Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908; and Department of Pathology, University of Virginia, Charlottesville, VA 22908
| | - Kenneth S Tung
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908; Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908; and Department of Pathology, University of Virginia, Charlottesville, VA 22908
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Abstract
BACKGROUND Multiple sclerosis (MS) is a disease in which safety is of paramount importance when developing a potential therapeutic. Antigen-specific treatments provide a method for achieving efficacy while maintaining safety. DNA vaccines are one such form of treatment that have been tested in clinical trials OBJECTIVE To determine if a DNA vaccine is a viable method of antigen-specific treatment of MS. RESULTS/CONCLUSION Phase I and II trials of BHT-3009, a DNA vaccine encoding myelin basic protein, demonstrated that it was safe, well-tolerated, and caused antigen-specific immune tolerance. BHT-3009 showed efficacy in reducing brain lesion activity as well as clinical relapses in patients that were immunologically active at baseline. BHT-3009 is a promising therapy in development for MS, and may prove to be one of the first antigen-specific treatments for this disease.
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Affiliation(s)
- Hideki Garren
- Stanford University, Department of Neurology and Neurological Sciences, Stanford, CA, USA.
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