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Gardner JK, Mamotte CDS, Patel P, Yeoh TL, Jackaman C, Nelson DJ. Mesothelioma tumor cells modulate dendritic cell lipid content, phenotype and function. PLoS One 2015; 10:e0123563. [PMID: 25886502 PMCID: PMC4401725 DOI: 10.1371/journal.pone.0123563] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 03/04/2015] [Indexed: 12/26/2022] Open
Abstract
Dendritic cells (DCs) play an important role in the generation of anti-cancer immune responses, however there is evidence that DCs in cancer patients are dysfunctional. Lipid accumulation driven by tumor-derived factors has recently been shown to contribute to DC dysfunction in several human cancers, but has not yet been examined in mesothelioma. This study investigated if mesothelioma tumor cells and/or their secreted factors promote increases in DC lipid content and modulate DC function. Human monocyte-derived DCs (MoDCs) were exposed to human mesothelioma tumor cells and tumor-derived factors in the presence or absence of lipoproteins. The data showed that immature MoDCs exposed to mesothelioma cells or factors contained increased lipid levels relative to control DCs. Lipid accumulation was associated with reduced antigen processing ability (measured using a DQ OVA assay), upregulation of the co-stimulatory molecule, CD86, and production of the tolerogenic cytokine, IL-10. Increases in DC lipid content were further enhanced by co-exposure to mesothelioma-derived factors and triglyceride-rich lipoproteins, but not low-density lipoproteins. In vivo studies using a murine mesothelioma model showed that the lipid content of tumor-infiltrating CD4+ CD8α- DCs, CD4- CD8α- DCs DCs and plasmacytoid DCs increased with tumor progression. Moreover, increasing tumor burden was associated with reduced proliferation of tumor-antigen-specific CD8+ T cells in tumor-draining lymph nodes. This study shows that mesothelioma promotes DC lipid acquisition, which is associated with altered activation status and reduced capacity to process and present antigens, which may impair the ability of DCs to generate effective anti mesothelioma T cell responses.
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Affiliation(s)
- Joanne K. Gardner
- Immunology and Cancer Group, School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
- CHIRI Biosciences Research Precinct, Curtin University, Perth, Western Australia, Australia
| | - Cyril D. S. Mamotte
- CHIRI Biosciences Research Precinct, Curtin University, Perth, Western Australia, Australia
| | - Priya Patel
- Immunology and Cancer Group, School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
- CHIRI Biosciences Research Precinct, Curtin University, Perth, Western Australia, Australia
| | - Teong Ling Yeoh
- Immunology and Cancer Group, School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
- CHIRI Biosciences Research Precinct, Curtin University, Perth, Western Australia, Australia
| | - Connie Jackaman
- Immunology and Cancer Group, School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
- CHIRI Biosciences Research Precinct, Curtin University, Perth, Western Australia, Australia
| | - Delia J. Nelson
- Immunology and Cancer Group, School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
- CHIRI Biosciences Research Precinct, Curtin University, Perth, Western Australia, Australia
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Mamotte CD, Sturm M, Foo JI, van Bockxmeer FM, Taylor RR. Comparison of the LDL-receptor binding of VLDL and LDL from apoE4 and apoE3 homozygotes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:E553-7. [PMID: 10070023 DOI: 10.1152/ajpendo.1999.276.3.e553] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Compared with apolipoprotein E3 (apoE3), apoE2 is less effective in mediating the binding of lipoproteins to the low-density lipoprotein (LDL) receptor. The influence of the E4 isoform, which is associated with adverse effects on plasma lipids and coronary heart disease, is less clear. We compared the ability of very low density lipoprotein (VLDL) and LDL from paired E4/4 and E3/3 subjects to compete against 125I-labeled LDL for binding with the LDL receptor on cultured fibroblasts and Hep G2 cells. The concentrations of VLDL or LDL required to inhibit binding of 125I-LDL by 50% (IC50, microgram apoB/ml) were determined, and results were assessed in terms of an IC50 ratio, E4/4 IC50 relative to E3/3 IC50, to reduce the influence of interassay variability. In Hep G2 cells, E4/4 VLDL was more effective than E3/3 VLDL in competing for the LDL receptor, the IC50 ratio being lower than unity (0.73 +/- 0.31, P < 0.05, two-tailed t-test). IC50 values themselves were marginally lower in E4/4 than E3/3 subjects (3.7 +/- 1.3 vs. 6.1 +/- 3.7, P < 0.08). However, there was no difference between E4/4 and E3/3 VLDL in competing for the LDL receptor on fibroblasts or between E4/4 and E3/3 LDL in competing for the LDL receptor on either cell type. These results suggest that inheritance of apoE4 is associated with an increased affinity of VLDL particles for LDL receptors on hepatocytes and may partly explain the influence of the E4 isoform on lipid metabolism.
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Affiliation(s)
- C D Mamotte
- Department of Biochemistry, Royal Perth Hospital, Perth, Western Australia 6001, Australia
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Verrips A, Wevers RA, Van Engelen BG, Keyser A, Wolthers BG, Barkhof F, Stalenhoef A, De Graaf R, Janssen-Zijlstra F, Van Spreeken A, Gabreëls FJ. Effect of simvastatin in addition to chenodeoxycholic acid in patients with cerebrotendinous xanthomatosis. Metabolism 1999; 48:233-8. [PMID: 10024088 DOI: 10.1016/s0026-0495(99)90040-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effects of combination therapy with chenodeoxycholic acid (CDCA) and simvastatin on serum cholestanol, low-density lipoprotein (LDL) cholesterol, and lathosterol levels were investigated in seven adult patients with cerebrotendinous xanthomatosis (CTX) who were on long-term treatment with CDCA. The patients were treated with a combination of CDCA 750 mg daily and an increasing dose of simvastatin from 10 mg to 40 mg daily for a period of 6 months. We found a significant effect of this combination therapy compared with CDCA alone in terms of decreasing the serum cholestanol and LDL cholesterol levels, particularly with a daily dose of 40 mg simvastatin. The mean cholestanol level decreased from 9.27 micromol/L (baseline) to 6.69 micromol/L (40 mg simvastatin), while the mean LDL cholesterol level decreased from 5.08 mmol/L (baseline) to 3.04 mmol/L (40 mg simvastatin). No side effects were reported, and there were no effects on the clinical condition, cerebral magnetic resonance imaging (MRI), visual evoked potentials, and electroencephalographic features. We conclude that a combination of 750 mg CDCA and 40 mg simvastatin daily is effective to further reduce serum cholestanol, LDL cholesterol, and lathosterol in adult CTX patients treated with long-term CDCA. Whether this combination treatment will be effective for the long-term prevention of neurological deterioration and atherosclerosis remains to be established.
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Affiliation(s)
- A Verrips
- Dutch Cerebrotendinous Xanthamatosis Research Group, University Hospital Nijmegen, The Netherlands
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