ABSTRACT
Objective To explore how the antibody of glucocorticoid-induced tumor necrosis factor receptor (GITR) exerts inhibitory effect on the L615 leukemia cells by strengthening the activation of the NK cells. Methods The 24 established L615 leukemia mice were equally and randomly divided into 4 experimental groups according to different drugs given intraperitoneally, groupⅠ (normal saline), Ⅱ (GITR), Ⅲ (cyclophosphamide), and Ⅳ (GITR +cyclophosphamide).Then the NK cells were extracted from the spleen of mice as effective cells, and L615 leukemia cells served as the target cells. The changes of the NK cells’killing activation was observed in vivo. The mRNA levels of 3 proteins tightly related to the NK cells’activation Perforin, IFN-? and Fas mRNAs were detected with RT-PCR. Results The GITR-antibody enhanced the killing activity of the NK cells obviously, with the expressions of the 3 proteins increasing obviously. Conclusion By regulation of the Treg cells, the GITR-antibody can inhibit the L615 leukemia cells through enhancing the NK cells' killing activity.