In Vitro Mimicking The Interactions Between Immune Cells And Tumor Cells In Tumor Microenvironment

In the previous study of our group, the tetrameric protein tfRFP, a fluorescent modal antigen of good performance, not only has good properties for fluorescence imaging, but can also elicit strong immune response in C57BL/6 mice. TfRFP-B16 tumor cells were killed and a large number of tfRFP+ microparticles were generated from tfRFP-B16 tumor cells in the tfRFP-B16 immunized mice. This phenomenon of generating tfRFP+ microparticles was not observed in the PBS-treated mice, indicating that the microparticles should be of distinct significance in the immunosurveillance of tumor. It drives us to reveal the detailed process of how tumor cells were killed by immunocytes as well as how microparticles were generated in the tumor microenvironment. We hypothesized that immunocytes elicited cell apoptosis through ADCC.This thesis aims to test our hypothesis by mimicking the process of immunocytes killing tumor cells in vitro. The followings are the main content in this paper:(1) Displaying microparticles generated from tumor cells and separating microparticles in vitro. We repeated the previous experiments by showing the microparticles in the tumor cryosections. The results showed that nearly all of the tumor cells were killed and a mass of microparticles were found in the tfRFP-immunized mice.(2) Imaging and mechanism study of the process that immunocytes attack tfRFP-B16 cells. Firstly, tfRFP-B16 cells were incubated with mouse sera and murine bone marrow cells, and then we observe tfRFP-B16 cells morphology change through confocal imaging and detect the survival rate of tfRFP-B16 cells by MTS. The results showed that tfRFP-B16 tumor cells were killed only when both the immune serum and mouse bone marrow cells were in presence at the same time. In conclusion, ADCC is an important mechanism of tumor cell death and particle release in the tfRFP-B16 immunized mice.