title: TLR2-mediated expansion of MDSCs is dependent on the source of tumor exosomes.
abstract: Exosomes released from tumor cells having been shown to induce interleukin-6 release from myeloid-derived suppressor cells in a Toll-like receptor 2/Stat3-dependent manner. In this study, we show that exosomes released from tumor cells re-isolated from syngeneic mice are capable of inducing interleukin-6 in a Toll-like receptor 2-independent manner, whereas the data generated from exosomes of tumor cells having undergone numerous in vitro passages induce interleukin-6 in a Toll-like receptor 2-dependent manner. This discrepancy may be due to the source of tumor cells used to generate the exosomes for this study. These results suggest that exosomes released from tumor cells that are not within a tumor microenvironment may not realistically represent the role of tumor exosomes in vivo. This is an important consideration since frequently passing tumor cells in vivo is an accepted practice for studying tumor exosome-mediated inflammatory responses.
authors.affiliation: Department of Microbiology & Immunology, JamesBrown Cancer Center, University of Louisville, Louisville, Kentucky 40202, USA.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Xiang
authors.forename: Yuelong
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiaoyin
authors.initials: X
authors.lastname: Zhuang
authors.forename: Shuangqin
authors.initials: S
authors.lastname: Zhang
authors.forename: Sue
authors.initials: S
authors.lastname: Michalek
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Taylor
authors.forename: William
authors.initials: W
authors.lastname: Grizzle
authors.forename: Huang-Ge
authors.initials: HG
authors.lastname: Zhang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D018920:Coculture Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D055354:Exosomes / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D008223:Lymphoma / Q000378:metabolism* / Q000473:pathology; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism* / Q000473:pathology; D008546:Melanoma, Experimental / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D022423:Myeloid Cells / Q000166:cytology / Q000378:metabolism*; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000378:metabolism*; D059016:Tumor Microenvironment
chemical_list: D015850:Interleukin-6; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; C493486:Tlr2 protein, mouse; D051195:Toll-Like Receptor 2
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