单次小剂量环磷酰胺对小鼠CD4(上标 +)CD25(上标 +)Treg细胞及抗肿瘤免疫力的影响

Objective To explore the effect of a single low-dose injection of conventional chemotherapy drug cyclophosphamide (CTX) on CD4(superscript +) CD25(superscript +)Treg cells in mice and it's anti-tumor effect. Methods Twenty C57BL/6 mice were divided into two groups, twenty mice in each group. The mice in CTX group were injected with CTX (20 mg•kg^(-1) dissolved in 0.2 mL saline) by intraperitoneal injection, and the mice in control group were injected with 0.2 mL saline by intraperitoneal injection. All of mice were given 0.5 mL cell suspension (including 2×10^6 RMA tumor cells) by subcutaneous injection after three days and were observed twenty days. 3-2,5-diphenyl-tetrazolium salt bromine was used to detect the expression of lymphocyte proliferation by Con A-induced in the lymphocytes of mice spleen. All mice were killed after the four days were intraperitoneal injected. The relative amount of CD4(superscript +) CD25(superscript +) Treg cells in the spleen of mice were detected by flow cytometry in the aseptic state; at the same time, the change of expression of scurfin protein in the spleen of mice were detected by western blotting. Results The percentage of CD4(superscript +)CD25(superscript +)Treg cells account for lymphocytes in CTX group was significantly lower than that in control group (P＜0.05); The density of scurfin protein expression in CTX group was significantly lower than that in control group (P＜0.05); The incidence of tumors in mice in CTX group was significantly lower than that in control group (P＜0.05); The weight of tumors after was attacked by tumor in mice in CTX group was significantly lower than that in control group (P＜0.05); A tumor was found in control group mice in 5th days after inoculation, but this time was extended to the eighth days after inoculation in CTX group; the curve of tumor growth is more steep in control group; and the curve is flat in CTX group relatively. The proliferation of lymphocyte in CTX group was higher significantly (P＜0.05). Conclusion A single low-dose CTX can improve the immune function and have some anti-tumor effects, this provides an experiment basis for the clinical tumor therapy.