4T1-derived exosomes downregulate NKG2D expression on NKp46+ splenocytes

The interaction between tumor-released exosomes and immune cells within the tumor microenvironment can significantly impact immune responses. Here we show that exosomes derived from the 4T1 mouse breast cancer cell line (4T1-Exs) affect natural killer group 2, member D (NKG2D) expression. We utilized flow cytometry to evaluate the influence of 4T1-Exs on the expression of the stress-detecting receptor, NKG2D, on NKP46 positive cells. Additionally, we examined the expression levels of inflammatory genes, including IFN-γ and FASL using quantitative real-time PCR (qRT-PCR). Our findings reveal that 4T1-Exs led to a decreased expression of NKG2D on NKP46 positive cells. We also observed a significant reduction in NKG2D, IFN-γ and FASL gene expression. Furthermore, our results indicate that 4T1-Exs considerably influence immune cell proliferation. Taken together, our results indicate that 4T1-Exs regulate NK cells by decreasing the NKG2D expression which might results in immune function against tumor cells.