The Effects of Released Exosomes from NK-92 Cells with IL15 on the Apoptosis of HL-60 Cell Line

Background: Most cancers are treated through chemotherapy and radiotherapy. However, these methods have limitations due to cancer cells evading immune detection, prompting researchers to explore alternatives such as immunotherapy. Nonetheless, cancer cells can weaken the immune response, necessitating improvements in immunotherapy methods. Exosomes, tiny cell-derived nanoparticles, reflect the traits of their originating cells. Natural Killer NK cells produce exosomes comprising perforin, granzyme, Fas-L, etc. The small size, proximity to tumors, and stability of these exosomes enable easy absorption by cancer cells. This study demonstrates that IL-15 impacts NK-derived exosomes, enhancing their ability to kill cancer cells. Materials and Methods: With the addition of 100 nanograms per milliliter of IL-15 to NK-92 cell culture, the cells are incubated for 48 hours. Exosomes are then isolated from treated and non-treated NK-92 cell lines through the ultracentrifuge method. After isolation, different concentrations of exosomes from both groups are added to HL-60 cells for treatment. After 24 hours, the apoptosis rate is assessed through the Annexin-V method. Results: Increased light absorption in the BCA test, along with thicker bands of CD63 and CD81 in the Western blotting test, indicates a higher yield of exosomes after adding IL-15 to the source cells. The low p-value from the t-test demonstrates that exosomes derived from stimulated NK cells are more cytotoxic than those from the control group. Further, two-way ANOVA confirms differences between the control and treatment groups at each concentration, and Welch's t-test proves that all differences in the ANOVA test are significant. Conclusion: This article presents evidence that exosomes obtained from IL-15-induced NK cells not only increase in quantity but also demonstrate significant cytotoxicity against leukemic cells compared to exosomes obtained from non-stimulated NK cells.