Study of Immunotherapy with Endogenous Opiod (Met-Enkephalin) Activated TILs in Fibrosarcoma Induced Balb/C Mice

Objective: In this study the effects of met-enkephalin on tumor infiltrating lymphocytesfor cancer treatment in fibrosarcoma bearing mice was evaluated.Materials and Methods: Initially, to obtain the most effective dose and treating time forthe inductionof CD25, splenocytes were cultured with several doses of met-enkephalin.Flowcytometry was used to evaluate CD25 expression. The best dose and treatingtime were used to stimulate tumor infiltrating lymphocytes (TILs). To obtain pure CD4+and CD8+ cells, TILs were taken from tumors by enzymatic tissue disaggregation andpurified by magnet bead cell separation. After TILs stimulation they were re-injectedinto three groups of other fibrosarcoma bearing mice. The first group received onlyCD4+ TILs, the second group received only CD8+ TILs, and the third group receivedboth CD4+ and CD8+ TILs. A fourth group that served as the control group receivedonly phosphate buffered saline (PBS). The effect of this treatment on tumor volume,mice survival, effector cells, regulatory T cells and serum level Bcl-2were evaluated.To analyze data in both the experimental and control groups one way ANOVA wasused followed by the Tukey test. P value