Combined Cytotoxic Effects Of NKTm Cells And Cisplatin On Human Breast Cancer Cells Lines In Vitro

【Background and Aims】TCRVαβand NK1.1 antigen of NKT cells are simultaneously expressed in mouse thymus,which was founded by Fowlkes in 1987.Unlikely to other T cells,the lipid antigens,which are transmitted by CD1d on cell membranes,can only be recognized by NKT cells.Their natural ligands are still unknown.Activated NKT cells can be transferred into cytotoxic and killing effector cells,and play a vital role in anti-tumor immunity,protective immunity response and immunoloregulation.The research shows that the incidence of tumor is related to the decrease of immunity,chemotherapy drugs can lead to the decrease of immunity.Nowadays,we are concentrate on whether the cytotoxic and immunoloregulation function of NKT cells can kill the tumor.The research of effects in the combination of chemotherapy and NKT cells to neoplasm has its practical importance.First of all,the study of synergism or antagonism effects,which are generated by the combination of NKT cells and chemotherapy,and how to arrange the sequence in order to acquire the maximum inhibition are necessary.The specific mechanisms are discussed according to the former results.This research applied the NK and T mixed cells(primarily are NKT cells subgroup,cultured in our laboratory) with cisplatin to MDA-MB-231 cells line.The inhibition effects and different sequential combination of both are observed.The inhibition effects of NKT cells to breast cancer cells line are discussed by analyzing the results.The change of immunocytes and tumor cells under the cytotoxic drugs are observed from the results,and provide some methods for the combination of immunotherapy and chemotherapy in clinical treatment.【Methods】Some activated NKT cells are collected and selected through NKT cells subgroup detection.The curves of survival rate,which are generated by activated NKT cells cultivated by our own laboratory combined with cisplatin,is recorded by MTT.The killing effects of breast cancer cells line MDA-MB-231 are recoded by the methods of MTT and flow cytometry. 【Results】NKT cells have the inhibition effects to breast cancer cells MDA-MB-231 in vitro from the inhibition experiments.But the inhibition rates are different from different persons.Under a certain concentration of cisplatin,the survival rate is obviously decreased by the combination in time dependent.The killing effects are increased when simultaneously use the two factors.The effects of NKT cells are the ratio of efficacy to target dependent.(p＜0.05).Compared with the groups with different sequences,the group that cisplatin is used 10 hours later than NTKm is superior to the opposite in MDA-MB-231.【Conclusion】1,The killing effects for breast cancer cells are different from the different source of NKTm cells.2,The tumor cells inhibition of NKTm have ratio of efficacy to target dependent property.3,The survival rate of NKTm itself is decreased with time extension.Although the NKTm cells are a little inhibited by cisplatin,they can achieved higher inhibition rate when given NKTm and cisplatin simultaneously.4,The maximum inhibition can be observed from the combination of NKTm cells and cisplatin.It is recommended that put NKT cells before chemotherapy when they are used together.