中文摘要：

目的：研究负载K-ras（12-Val）抗原的树突状细胞（DCs）活化的特异性细胞毒性T淋巴细胞（CTLs）对胰腺癌的体外杀伤作用。方法：联合应用粒细胞-巨噬细胞集落刺激因子（rhGM-CSF）和白细胞介素4（IL-4）诱导培养外周血DCs。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DCs。流式细胞仪测定DCs表面标志;3H-TdR掺入法检测细胞增殖,125I-UdR法检测CTL杀伤效应,ELISA试剂盒检测IL-12和IFN-γ。结果：与单纯K-ras（12-Val）突变体多肽相比,K-ras（12-Val）突变体表位肽阳离子纳米颗粒在低浓度时即可被DCs有效提呈（P〈0.05）;负载全瘤抗原的DCs诱导产生的CTL与负载单纯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诱导组相比对Patu8988（K-ras＋）及SW1990（K-ras-）胰腺癌细胞均有明显杀伤活性（P〈0.05）,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DCs诱导产生的CTL对Patu8988（K-ras＋）细胞株有特异性杀伤活性（P〈0．05），而对SWl990（K-ras-）细胞株无杀伤作用（P〉0．05）。结论：低浓度K-ras（12-Val）突变体表位肽阳离子纳米颗粒作用后，在短时间即可被DCs有效提呈，且诱导产生的CTL对表达K-ras（12-Val）突变体的胰腺癌细胞株有特异性杀伤活性。

英文摘要：

Objective：To investigate the antitumor efficiency of the special cytotoxic T lymphocytes（CTLs） activated by dendritic cells （DCs） pulsed with K-ras （12-Val） antigen.Methods： DCs was generated from PBMC in the presence of granuloceyte/macrophage-colony stimulating factor（GM-CSF）,interleukin-4（IL-4）in vitro. DCs were differently sensitized with K-ras mntant pancreatic cancer cell line, K-ras（ 12- Val） mutant peptide, K-ras（12-Val） mutant peptide with the surface of cationic nanoparticle. Cell surface markers on DCs was measured by flow cytometry. The activation of CTL induced by DCs was detected by ^3H-thymidine incorporation test. The killing effects of CIL to pancreatic cancer was detected by ^125I-UdR release test. Production of IL-12 and IFN-γ by DCs and PBMC was detected by ELISA. Results： Compared with DCs pulsed with K-ras（12-Val） mutant peptide and K-ras （12-Val） mutant peptide with the surface of cationic nanoparticle, DCs pulsed with whole tumor antigen could better induce CTLs killing activity（P 〈 0.05）.The DCs with K-ras（12-Val） mutant peptide and K-ms mutant peptide with the surface of cationic nanoparticle could produce specific CTL killing activity aganist pancreatic cancer cell line Patu8988（ K-ras ＋ ）（P〈0.05）,but not SW1990（K-ras- ）（P 〉 0.05）. K-ras （12-Val） mutant peptide with the surface of cationic nanoparticle at lower concentrations can be effectively presenting on the surface of DCs than only K-ras （12-Val） mutant peptide. Conclusion： K-ms （12-Val） mutant peptide with cationic carrier can be effectively presenting and expression of DCs and induce CTL specific killing activity aganist pancreatic cancer cell lines with K-ras （12-Val） mutant peptide.