In Vivo Immunogenicity Screening of Tumor-Derived Extracellular Vesicles by Flow Cytometry of Splenic T Cells


Posted: 2021-10-11 19:00:00
Immunogenic cell death of tumors, caused by chemotherapy or irradiation, can trigger tumor-specific T cell responses by releasing danger-associated molecular patterns and inducing the production of type I interferon. Immunotherapies, including checkpoint inhibition, primarily rely on preexisting tumor-specific T cells to unfold a therapeutic effect. Thus, synergistic therapeutic approaches that exploit immunogenic cell death as an intrinsic anti-cancer vaccine may improve their responsiveness. However, the spectrum of immunogenic factors released by cells under therapy-induced stress remains incompletely characterized, especially regarding extracellular vesicles (EVs). EVs, nano-scale membranous particles emitted from virtually all cells, are considered to facilitate intercellular communication and, in cancer, have been shown to mediate cross-priming against tumor antigens. To assess the immunogenic effect of EVs derived from tumors under various conditions, adaptable, scalable, and valid methods are sought-for. Therefore, herein a relatively easy and robust approach is presented to assess EVs' in vivo immunogenicity. The protocol is based on flow cytometry analysis of splenic T cells after in vivo immunization of mice with EVs, isolated by precipitation-based assays from tumor cell cultures under therapy or steady-state conditions. For example, this work shows that oxaliplatin exposure of B16-OVA murine melanoma cells resulted in the release of immunogenic EVs that can mediate the activation of tumor-reactive cytotoxic T cells. Hence, screening of EVs via in vivo immunization and flow cytometry identifies conditions under which immunogenic EVs can emerge. Identifying conditions of immunogenic EV release provides an essential prerequisite to testing EVs' therapeutic efficacy against cancer and exploring the underlying molecular mechanisms to ultimately unveil new insights into EVs' role in cancer immunology.

参考サイト PubMed: exsome



バイオクイックニュース日本語版:エクソソーム特集

バイオクイックニュース日本語版
7月 14, 2014 バイオアソシエイツ

幹細胞から放出されたエクソソーム中の特定miRNAが卒中からの回復に関与

Henry Ford Hospitalの研究チームは、動物を使った新しい研究で、卒中発作後に幹細胞から放出される エクソソーム と呼ばれる微小な (50nm) 脂質性の細胞内器官に内包されるRNA (リボ核酸) 塩基配列のごく短いmicroRNAのうち、特定のものが神経的な回復に一役買っていることを突き止めた。研究チームのラットを用いた実験では、この特定のmicroRNAが幹細胞からエクソソームを使って脳細胞に送られ、卒中発作後の機能回復を強化していた。…

ゲスト 720人 と メンバー 6人 がオンラインです