An Elementary Study On The Mechanisms Of Vα24NKT Cells From Human Peripheral Blood Cells In Anti-tumor Immunity And A Comparative Study On The Biological Characteristics Of Vα24NKT Cells And CD3～+CD56～+CIK Cells

V α 24 Natural killer T (NKT) cells are a population of T cells that share some characteristics with natural killer (NK) cells. After activated, V α 24 NKT cells can kill tumors directly as the anti-tumor effectors and they can also activate other cell types, such as NK cells, to mediate anti-tumor effects indirectly. V α 24 NKT cells play an important role in anti-tumor immunity, adaptive immune responses and immunoregulation.To confirm the function of the V α 24NKT cells and their mechanisms in anti-tumor immunity, the V α 24NKT cells from human peripheral blood cells were expanded and purified in our research. The phenotype and the level of expression on cytokine and necrosis-related factors of V α 24NKT cells were determined by flow cytometry and RT-PCR. The cytotoxicity of V α24NKT cells was measured by the means of DIOC18 staining and flow cytometry and the blocking assay had been done with different medications. The most of Va24 NKT cells were CD4~+ and DN NKT cells. They showed a high level of expression on TCRV α 24,V β 11,CD3 and CD161 and a low level of expression on CD56. Under the stimulation of antigen, V α 24NKT cells secreted high level of IFN- γ and IL-4, they also had the high level of expression on TNF- α , Perforin, FasL and TRAIL. In addition, the cytotoxic effect of V α 24NKT cells to the tumor cell lines expressing CD1d was more intense. And the killing activity was enhanced in the present of α -GalCer. When each of the Perforin, FasL, TNF- α and TRAIL cytotoxic effect was blocked, ConA has the strongest effect on blocking. It is evident that Va24NKT cells can directly kill tumor cell lines in a CD1d-dependent and antigen-dependent manner through a combination of Perforin and TNF-family members killing. Meanwhile, it is apparent that Perforin dominated in the killing assay.To confirm the difference of the biological characteristics between the V α 24 natural killer T cells (NKT) and the cytokine-induced killer cell (CIK), the V α 24 NKT cells and CIK cells from human peripheral blood cells were expanded. And the purified Va24 NKT cells and CD3~+CD56~+CIK cells were obtained by using Dynal...