Naslov
Identification of a transformed subpopulation of liver epithelial cell-derived microvesicles that stimulate NK cytotoxicity

Autori
Srajer Gajdosik, Martina ; Yang, DongQin ; Pantazatos, Dennis ; Cao, Lulu ; Josic, Djuro ; Brilliant, Kate. E. ; Chatterjee, Devasis ; Quesenberry, Peter J. ; Hixson, douglas C. ; Mills David R.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts from Second International Meeting of ISEV 2013 / - Boston (MA), 2013, 126-126

Skup
International Meeting of ISEV

Mjesto i datum
Boston (MA), Sjedinjene Američke Države, 17.04.2013. - 20.04.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
microvesicles; NK cytotoxicity; liver epithelial cell; malignant transformation

Sažetak
Introduction: Microvesicles (MV) have been described as playing important roles in cancer progression and regulation of immune cell responses. Here, we examined MVs released from the stem-like liver epithelial line WB-344 (WB), GP7TB (GP7), a transformed line derived from WB, and GP7TB.SA, a subpopulation of GP7 cells isolated in soft agar assays and describe the effect of GP7 and GP7.SA-derived MVs on rat hepatic natural killer (NK) cell activity. Material and methods: Proteomic analysis was completed at the Rhode Island Hospital Center of Biomedical Research Excellence (COBRE) Proteomics Core Facility (Providence, RI). Hepatic NK cells were isolated from Fischer rats using antibodies to remove B cells, T cells, monocytes, macrophages and granulocytes. Isolated NK cells were incubated in the presence or absence of cell-derived MVs for 1h at 37°C and NK cytotoxicity was measured against YAC-1 target cells using a 4 h 51Cr-release assay. Results: Electron microscopy showed differences in the size (WB>GP7>GP7.SA) and number (WB<GP7<GP7.SA) of shed MVs. Proteomic comparison of WB vs GP7 MV showed 70 proteins unique to the GP7 population mainly associated with cell adhesion and intracellular signaling. Comparison of GP7 vs GP7.SA identified 68 proteins unique to the GP7.SA population mainly involved in regulation of cell death and motility. Necl-5 interacts with CD226 on NK cells to induce cytolytic killing and was found on GP7 and GP7.SA MVs. Pre-incubation of hepatic NK cells with GP7.SA-derived MVs significantly stimulated NK- mediated cytotoxicity. In contrast, MVs purified from GP7 had no effect. Conclusions: Changes identified between these related cell lines are reflected in extracellular vesicle release as determined by morphology, proteomics and function. Cytolytic studies show that Necl-5 expression on MVs is not sufficient to modulate NK activity. This model has the potential to identify co- activating molecules that stimulate the NK anti- tumour response.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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