抗原致敏白细胞介素-2基因修饰的树突状细胞对肿瘤术后自发性肺转移的抑制作用

Inhibition of pulmonary metastasis by MHC class I tumor antigen peptide pulsed,interleukin 2 gene modified dendritic cells

目的 探讨主要组织相容性复合物 (MHCI)类肿瘤抗原多肽体外致敏、白细胞介素(IL) 2基因修饰的树突状细胞 (DC)对小鼠恶性肿瘤切除术后自发性肺转移的体内抑制效果及相关免疫机制。方法 用小鼠Lewis肺癌 3LL细胞株MHCI类肿瘤抗原八肽Mut1致敏IL 2基因修饰的DC(DC IL 2 Mut1) 2× 10 6/ml免疫小鼠 ,用 3LL细胞每只 5× 10 6/ml皮下荷瘤 ,观察免疫保护情况 ;并用抗CD4 + 、CD8+ 和NK1.1+ 单克隆抗体体内阻断免疫细胞亚群 ,探讨DC IL 2 Mut1在小鼠体内诱导的特异性抗肿瘤机理。用DC IL 2 Mut1给小鼠肿瘤自发性肺转移模型尾静脉注射 ,观察对肺转移的抑制效果。结果 免疫小鼠荷瘤后第 2 0天 ,磷酸盐缓冲液 (PBS)对照组肿瘤直径为 ( 2 0 .0± 2 .0 )mm ,DC IL 2 Mut1免疫组未见肿瘤生长。抗CD8+ 单克隆抗体能部分阻断其免疫保护作用 ,而抗CD4 + 和CD8+ 单抗联合应用 ,能完全阻断DC IL 2 Mut1在小鼠体内诱导的特异性免疫效应 ,抗CD4 + 和抗NK+ 细胞单抗有一定的阻断效果。荷瘤截肢术后 2 0d ,对照组小鼠肺重量为 ( 110 5 .0± 113.0 )mg ,肺表面转移结节为 ( 4 8.8± 4.5 )个 ;DC IL 2 Mut1组肺重为 ( 2 13.0±2 8.5 )mg,肺表面肉眼未能看到转移结节 ,生存期较其他各组明显延长。结论 IL

Objective To investigate the inhibitory effects of pulmonary metastasis after 3LL Lewis lung carcinoma resected by the interleukin(IL) 2 geneo modified and MHC I restricted tumor antigen pulsed dendritic cells (DC) in mice and relative mechanisms.Methods The syngeneic mice were immunized by DC modified by IL 2 gene and pulsed with mouse MHC I restricted tumor antigen peptide Mut1 of 3LL Lewis lung carcinoma cells (DC IL 2 Mut1)2×10 6/ml and subsequently challenged with 3LL cells (5×10 6/ml), then the tumor growth size was observed. During DC IL 2 Mut1 immunization, CD 4 +T cells, CD 8 +T cells or NK cells were depleted with specific MoAb to explore their roles in DC induced antitumor immunity. The tumor bearing mice with spontaneous pulmonary metastasis were vaccinated by DC IL 2 Mut1, and the inhibitory effects were observed.Results Twenty d after inoculating tumor cells in the immunized mice, the diameter of tumor were (20.0±2.0)mm in the group of PBS control, but no any tumor was found in the DC IL 2 Mut1 immunized group. Immunization with DC IL 2 Mut1 could protect the mice from subsequent re challenge of 3LL Lewis lung carcinoma. Depletion of CD 8 + T cells could partially block the protection immunity induced by DC IL 2 Mut1 and depletion of both CD 8 + and CD 4 + T cells completely inhibited the antitumor effects.20?d after surgery,the mice lung weight were(1?105.0±113.0)?mg and nodes on lung face were 48.8±4.5 in the group of PBS control. The lung weight in the group of DC IL 2 Mut1 immunized was(213.0±28.5)?mg and no nodes were found on lung face and their survival was extended more potently.Conclusion IL 2 gene transfer into DC could augment the efficacy of tumor antigen peptide pulsed DC in the induction of immune responses and could inhibit tumor spontaneous pulmonary metastasis. CD 8 +T cells play important roles during induction of immune responses.