K-ras抗原致敏的DC诱导CTL对胰腺癌体内杀伤活性的研究

Anti-tumor Effect of Specific Cytotoxic T Lymphocytes Activiated by Dendritic Cells Pulsed with K-ras Antigen on Pancreatic Cancer

目的:研究K-ras多肤的致敏树突状细胞(DC)活化的特异性细胞毒性T淋巴细胞(CTL)对胰腺癌的体内外杀伤作用。方法:联合应用粒细胞-巨噬细胞集落刺激因子和白细胞介素-4诱导培养外周血DC。表达K-ras突变体的胰腺癌细胞株全瘤、单纯K-ras突变体多肽和K-ras突变体表位肽阳离子纳米颗粒分别致敏DC。致敏DC刺激T淋巴细胞得到肿瘤抗原特异的细胞毒性T淋巴细胞(CTL)。Patu8988、SW1990细胞系制备荷瘤裸鼠模型评价CTL体内抗肿瘤活性。结果:负载全瘤抗原的DC其诱导产生的CTL对胰腺癌有较好的抑制,负载单纯K-ras(12-Val)突变体多肽、K-ras(12-Val)突变体表位肽阳离子纳米颗粒的DC其诱导产生的CTL对表达K-ras(12-Val)突变体阳性(Patu8988)的胰腺癌有较特异的抑制作用,而对K-ras(12-Val)突变体阴性(SW1990)的胰腺癌的抑制作用与对照组比较无显著性差异结论:负载肿瘤抗原的DC诱导的CTL可显著提高对荷瘤裸鼠的生存时间,抑制肿瘤的生长速度,并显示其可增加抗肿瘤特异性。

Objective： To investigate the anti-tumor effect of cytotoxic T lymphocytes （CTLs） activated by dendritic cells （DCs） pulsed with K-ras antigen. Methods： DCs were generated from PBMC in the presence of GM-CSF and IL-4 in vitro. DCs were sensitized with pancreatic cancer cell line expressing K-ras mutant, K-ras （12-Val） mutant peptide, K-ras （12-Val） mutant peptide with the surface of cationic nanoparticle. The mature DCs were cocultured with autologous T cells to obtain antigen specific CTL. The anti-tumor activity of CTL in vivo was evaluated in BALB/c nude mice bearing Patu8988 （K-ras＋） and SW1990 （K-ras-） pancreatic cancer. Results： CTLs cocultured with DCs with the whole tumor antigen significantly inhibited the growth of transplanted pancreatic cancer （Patu8988 and SW1990） in nude mice. In vivo experiments showed that DCs with K-ras （12-Val） mutant peptide and K-ras mutant peptide with the surface of cationic nanoparticle induced killing activity of specific CTL aganist pancreatic cancer cell line Patu8988 （K-ras＋） （P〈0.05）. Conclusion： CTL induced with DCs pulsed with K-ras antigen can significantly improve the survival of nude mice with pancreatic cancer, through inhibiting tumor growth.