Abstract:

Objective To explore the influence on function and activity of rituximab of Raji cells via 4-1BBL gene transfection. Methods Stable expression of 4-1BBL in Raji cells was carried out through transfection mediated by liposome. The experiments contained 4-1BBL group，Mock group and control group. The 4-1BBL expression was identified by Western blotting analysis at 48h after transfection. CCK-8 method was used to detect the proliferation at 48h after treatment with different concentrations （20.0， 10.0， 5.0， 2.5， 1.25， 0.625 mg／ml） of rituximab. The proliferation rates of lymphocyte and supernatant IL-2 levels at 48h after co-culture with the activated peripheral blood lymphocytes under the effector／target ratio of 5∶1 and 10∶1 by CCK-8 and enzyme-linked immunosorbent assay. Results The protein level of 4-1BBL in 4-1BBL group was higher than those in Mock group and control group （P＜0.05）. The proliferative rates decreased with the increasing concentrations of rituximab in 4-1BBL group. When the concentration was over 2.5mg／ml， there were lower proliferative rate in 4-1BBL group versus Mock group and control group （P＜0.05）. Under the effector／target ratio of 5∶1 and 10∶1， the proliferative rate of lymphocyte and supernatant IL-2 level in 4-1BBL group was higher than those in Mock group and control group （P＜0.05）. Conclusion The 4-1BBL gene transfection can enhance the activity of rituximab on Raji cells， suggesting that combined activation of 4-1BBL and targeting-antibody may be a new strategy for cancer immunotherapy.