负载K-ras抗原的DCs诱导CTLs对胰腺癌的体外杀伤作用

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,~(125)I-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SW1990(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.

Antitumor efficacy of specific cytotoxic T lymphocytes activiated by dendritic cells pulsed with K-ras antigen to pancreatic cancer ex vivo

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 mutant 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 CTL to pancreatic cancer was detected by ~(125)I-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-ras 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-ras (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.