P-01.04 Sensitivity of different cell lines to NK cell lysis

<h3>Background</h3> NK cells are a specific population of nonspecific immunity that is responsible for the elimination of tumor cells in a special way, unlike T lymphocytes. In clinical and experimental work, various tests are used to study NK cell function. The test used in this study is based on joint in-vitro cocultures of NK cells and appropriate target tumor cells. <h3>Materials and Methods</h3> K-562, MDS and Femix cells were cultured in RPMI 1640 medium supplemented with 2 mM glutamine, 10% of FCS and antibiotics and were used as target cells for the study of NK cell function. Isolated lymphocytes from healthy volunteer donors were used as a source of NK cells. The classic NK test, a test based on the use of radioactive chromium, was applied in this study and compared with the findings of flow cytometry. Flow cytometry was used to determine cell membrane antigens and the degree of apoptosis, and the LDH test was used to determine necrosis. <h3>Results</h3> In this study, it was shown that K-562 showed the highest sensitivity to NK function, while other hematological cells such as MDS showed high spontaneous necrosis, which correlated with high release of radioactive chromium after a short-term incubation of 30 min. When comparing NK activities in various ratios of effector and target cells, in all ratios K-562 showed statistically significantly higher sensitivity compared to other cell lines. <h3>Conclusions</h3> This work shows that K-562 are the gold standard for testing NK cell function and are most used in laboratory and clinical work due to their characteristics, which we also recommend and use in research. V. Jurisic: None.