MCF-7荷瘤裸鼠不同树突状细胞亚群凋亡的研究

Apoptosis of dendritic cell subsets in MCF-7 tumor-bearing nude mice

目的:通过建立MCF-7荷瘤裸鼠模型,研究树突状细胞(DCs)不同亚群的凋亡,为设计新的免疫治疗方法和新的疫苗提供详尽信息。方法:建立MCF-7裸鼠模型,随机分为荷瘤组和对照组,肿块达5 mm后处死裸鼠,取骨髓单个核细胞进行DCs诱导、分化,流式细胞仪上检测表面分子标志CD86、CD83、MHC-Ⅱ及CD34,AnnexinⅤ检测CD11c及CD123了解DCs亚群的凋亡率。结果:骨髓起源单个核细胞培养至第9天出现典型DCs形态特征,荷瘤组和对照组细胞均高表达CD86、CD83及MHC-Ⅱ,而CD34表达两组均较低。荷瘤组CD11c+CD123-细胞为(52.01±1.43)%,对照组为(56.36±1.76)%;CD123+CD11c-细胞荷瘤组为(32.19±1.71)%,对照组为(28.95±1.39)%。荷瘤组mDC凋亡率为(23.64±2.43)%,较对照组(20.05±2.49)%高,P<0.05。荷瘤组小鼠pDC凋亡率为(11.53±2.92)%,较对照组(14.96±2.96)%低,P<0.05。结论:MCF-7乳腺癌小鼠体内DCs存在mDC和pDC两种亚型,mDC凋亡率增加,使诱导Th1免疫反应能力减低;而pDC凋亡率减少,诱导体内免疫耐受的发生,机体抗肿瘤免疫反应能力因而下降。

OBJECTIVE：Establishing MCF-7 tumor-bearing mice and studying the apoptosis of DCs subsets,in order to give the particular information to design the new immune-therapeutic method and new vaccines in breast cancer. METH- ODS： MCF-7 cell line was implanted subcutaneously in BALB/C nude mice to develop implant-tumor. Then the nude mice were randomly allocated into two groups. Mice were sacrificed when tumor size reached 5mm in diameter. Bone marrow- derived mononuclear cells were induced and differentiated. DCs were identified by flow cytometry. The apoptosis of DC subsets were verified by Annexin V using flow cytometry. RESULTS： The obvious morphologic characteristics of DCs were observed when the bone marrow-derived monoelear cell had been cultured for 9days. High level expressions of CD86, CD83 and MHC-I] were similarly observed in two groups, while the expression of CD34 was very low. The cells of CD11 c＋ CD123- in tumor-bearing mice was （52.01±1.43）% and that of control mice was （56.36 ±1.76）%. The cells of CDllc CD123＋ in tumor-bearing mice was （32.19±1.71）% ,while that of control mice was （28.95±1.39）%. The pro- portion of apoptotic mDCs in tumor-bearing mice was significantly increased [ （23.64± 2.43）%, vs （20.05 ± 2.49） %, P〈0.05]. In contrast, in tumor-bearing mice, the percentage of apoptotic pDC was lower than that in control mice [ （11.53 ± 2.92） 0% vs （ 14.96±2.96）%, P 〈 0.05 ]. CONCLUSIONS： MDC and pDC are two mDC subsets of MCF-7 breast cancer mice. The rate of apoptotic mDCs in tumor-bearing mice is higher significantly than that in control mice. It suggests that mDC in MCF-7 breast cancer mice induced a weak Thl response. The rate of apoptotie pDCs in tumor-bear- ing mice is lower significantly than that in control mice. It suggested that pDC induced immune tolerance, which resulted indecreasing the antitumor immune responses in vivo.