冷冻联合免疫疗法治疗小鼠B16黑素瘤

COMBINED CRYOTHERAPY AND IMMUNOTHERAPY FOR MOUSE B16 MELANOMA

目的 探讨冷冻治疗附加免疫治疗可能获得更好的抗肿瘤疗效。方法 B16黑素瘤皮下接种 C5 7BL / 6小鼠 ,待肿瘤长至 3mm～ 5 m m时荷瘤鼠分为四组。 1冷冻免疫组 :第 0天 ,用深部冷冻治疗仪治疗荷瘤鼠 1次。冷冻治疗前2天每只小鼠腹腔注射 1mg环磷酰胺 1次 ,肿瘤局部每天注射 IFN -α 5万单位 ,共 2天。从第 0天至第 10天 ,每天给小鼠注射 1万单位 r IL - 2。 2、3、4组分别为冷冻治疗组、免疫治疗组和未治疗对照组。根据肿瘤大小和存活时间评价疗效。用 3H- Td R释放法测定脾细胞的细胞毒活性。结果 肿瘤接种后第 31天 ,仅第 1组肿瘤平均大小与对照组相比有显著差异 (P<0 .0 1)。各组平均存活期依次为 6 8.7、5 5 .3、5 1.6和41天。肿瘤完全缓解率组 1为 43.8% ,组 2为 11.8% ,而其他两组无 1例缓解。组 1治愈小鼠用 B16再次攻击均未产生肿瘤。组 1小鼠脾细胞体外细胞毒实验按效靶比为 5 0∶ 1时 ,对 B16的杀伤率为 42 .1% ,对 EL 4杀伤仅为 3.5 %。结论 用 IFN -α和 r IL - 2免疫治疗协同冷冻治疗可能通过诱发全身性、特异性抗肿瘤免疫反应 ,获得更好的疗效。

Objective To study if cryotherapy combined with immunotherapy could achieve better therapeutic effect than either used alone. Methods C57BL/6 mice were inoculated subcutaneously with B16 melanoma. When the tumor grew to 3 mm～5 mm in diameter, the tumor bearing mice were divided into 4 groups. 1. Cryo immunotherapy group: On day 0, the mice were treated once by deep freezer. Immunotherapy started from day 2, mice received by ip injection of 1 mg cyclophosphamide and peritumoral injection of rIFN α(5×10 3 U),for 2 days. On day 0 to day 10, mice were daily injected with rIL 2(10 4 U) Group 2,3 and 4 was Cryotherapy, Immunotherapy and Untreated control respectively. The therapeutic effect was assessed by tumor size and survival time. Cytotoxicity of spleen cells was examined by 3H TdR release assay.Results On day 31, the average tumor size of mice only in group 1 showed a statistically significant difference ( P <0 01) with that in the control mice. The average surviving time of the 4 groups of mice was 68 7, 55 3,51 6 and 41.0 days respectively. Complete tumor regression was observed in 43.8 % of grup 1 mice and 11.8 % of group 2 mice, but none in other two groups. Mice in group 1 with their tumor regressed were rechallenged with B16 cells, but no tumor growth occurred. In vitro cytotoxicity of spleen cells from group 1 mice was 42.1 % against B16 cells and 3.5 % against EL 4 cells (E∶T ratio=50).Conclusion Immunotherapy with IL 2 and IFN α synergies with cryotherapy possibly enhance a systemic, specific anti tumor immune response.