转染B7基因的U14疫苗对小鼠宫颈癌的防治作用研究(英文)

Therapeutic antitumor response to cervical cancer in mice immunized with U14 vaccines transfected with costimulatory B7 gene

目的 探讨转染B7基因的U14疫苗能否在体内诱导中国 615系小鼠抗宫颈癌主动免疫应答。方法 将小鼠B7 1基因导入 615系小鼠宫颈癌U14细胞 ,建立高效表达B7 1的U14细胞株 (B7+U14)及其细胞疫苗。 ( 1)用B7+U14疫苗免疫 ,预防 615系小鼠皮下移植成瘤。 ( 2 )用B7+U14疫苗治疗 615系荷瘤小鼠。设立对照组 ,观察各组小鼠的成瘤情况、生存期。 ( 3)体外检测经B7+U14和U14疫苗免疫小鼠T细胞杀伤肿瘤实验。结果 将B7基因转染入U14细胞后获得了B7 1高表达克隆株 (B7+U14)。 ( 1)B7+U14疫苗免疫 ,可有效预防野生型U14细胞移植瘤产生 (比较肿瘤大小、生存期 :P <0 0 1)。 ( 2 )B7+U14疫苗能治愈部分荷瘤小鼠 ,其效果受荷瘤大小限制 ,即肿瘤直径 >3mm时 ,B7+U14疫苗治疗无效 (P <0 0 5)。 ( 3)体外检测经B7+U14和U14疫苗免疫小鼠 ,前者T细胞在不同效靶比杀伤肿瘤效率明显高于后者 (F =310 8,组间有显著差异P <0 0 0 1)。结论 转染B7基因的U14细胞疫苗能诱导机体有效的抗宫颈癌主动免疫应答。提示应用转染B7基因的肿瘤细胞疫苗可能成为临床术后治疗宫颈癌的有效辅助方法。

Objective To investigate the effect of U14 vaccine transfected with the B7 gene in inducing antitumor immune response to murine cervical carcinoma in Chinese 615-strain mice.Methods A recombinant retroviral plasmid vector expressing mouse B7-1 gene (pLNSX-mB7) was transfected into 615-strain mouse cervical carcinoma cell line No. 14 (U14) by electroporation to set up a highly-expressed mB7-1 U14 cell clonal strain (B7+U14). In vivo experiments: (1) B7+U14 vaccine was primed to protect the 615-strain mice against U14 re-challenge. (2) B7+U14 vaccine was injected into tumor-bearing mice with different tumor sizes. Lifetimes and tumor sizes were recorded. In vitro cytotoxicity assay: Mice were immunized with B7+U14 or U14 vaccine and 2 weeks later, spleen cells of those mice were cultured for 2 days. The cytotoxicity of these cells against U14 was detected by 5-diphenyl tetrazolium bromide assay.Results We obtained several B7-1 high expression clonal U14 lines. In vivo experiment, we did not find tumor growing in 3 of the 6 mice primed by B7+U14 vaccine during their entire life after re-challenge with U14. The other 3 mice developed tumors and their average survival time was longer than that of the control group (P<0.01). All 6 mice grew tumors in the control group. When the transplanted tumors became palpable, the mice were randomly divided into 3 groups to be injected with B7+U14 vaccine. It was effective for tumor-bearing mice only when the tumor diameters were <3?mm. When the diameters were ≥3?mm, it was not efficacious to inject B7+U14 vaccine (P<0.05). In vitro cytotoxicity assay, cytotoxic T lymphocytes induced by B7+U14 vaccine had a higher cytotoxicity against U14 than that induced by U14 vaccine (F=310.8, P<0.001).Conclusions Vaccines of cervical cancer cells transfected with the costimulatory molecule B7 gene can induce antitumor immune protection in host mice against U14 re-challenge. This treatment may cure part of the tumor-bearing mice but be restricted by tumor size. The results suggest that transfecting the B7 gene into cervical cancer as a cell vaccine may be an efficient supplementary method to treat cervical cancer after operation.