Enhancement of antitumor potency of extracellular vesicles derived from natural killer cells by IL-15 priming

Autor: Prakash Gangadaran, Sang-Woo Lee, Senthilkumar Kalimuthu, Liya Zhu, Se Hwan Baek, Shin Young Jeong, Ji Min Oh, Jaetae Lee, Byeong-Cheol Ahn
Rok vydání: 2019
Předmět:
Zdroj: Biomaterials. :38-50
ISSN: 0142-9612
Popis: Purpose Natural killer (NK) cells are the key subset of innate-immunity lymphocytes; they possess antitumor activities and are used for cancer immunotherapy. In a previous study, extracellular vehicles (EVs) from NK-92MI cells were isolated and exploited for their ability to kill human cancer cells in vitro and in vivo (multiple injection methods). Here, the potential of NK-cell–derived EVs (NK-EVs) for immunotherapy was improved by priming with interleukin (IL)-15. Methods NK-EVs were isolated from the culture medium without or with IL-15 (NK-EVsIL-15) by ultracentrifugation and were purified via density gradient ultracentrifugation. In addition, NK-EVs and NK-EVsIL-15 were characterized by transmission electron microscopy, nanoparticle-tracking analysis, and western blotting. Flow cytometry, bioluminescence imaging, and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay were performed for apoptosis, protein expression, cell proliferation, and cytotoxicity analyses. Furthermore, xenograft tumor–bearing mice were injected with PBS, NK-EVs, or NK-EVsIL-15 intravenously five times. Tumor growth was monitored using calipers and bioluminescence imaging. Toxicity of the nanoparticles was evaluated by measuring the body weight of the mice. Results NK-EVsIL-15 showed significantly higher cytolytic activity toward human cancer cell lines (glioblastoma, breast cancer, and thyroid cancer) and simultaneously increased the expression of molecules associated with NK-cell cytotoxicity. When compared with NK-EVs, NK-EVsIL-15 significantly inhibited the growth of glioblastoma xenograft cells in mice. In addition, both NK-EVs and NK-EVsIL-15 were not significantly toxic to either normal cells or mice. Conclusion IL-15 may improve the immunotherapeutic effects of NK-EVs, thus improving the applications of NK-EVs in the future.
Databáze: OpenAIRE