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目的比较免疫球蛋白κ轻链启动子/增强子和免疫球蛋白重链启动子/增强子控制的白喉毒素A链基因对淋巴瘤细胞生长抑制。方法将白喉毒素A链基因或细菌β半乳糖苷酶基因与免疫球蛋白启动子/增强子相连构建成白喉毒素A链真核表达载体pcDNA3IgκDTA、pcDNA3IgHDTA或细菌β半乳糖苷酶真核表达载体pcDNA3IgκLacZ、pcDNA3IgHLacZ。由脂质体介导将质粒转染至产或不产免疫球蛋白的真核细胞中,检测β半乳糖苷酶基因在不同细胞中的表达水平,并进一步检测白喉毒素A链基因的表达对转染细胞的生长抑制作用。结果由免疫球蛋白κ轻链启动子/增强子或免疫球蛋白重链启动子/增强子控制的β半乳糖苷酶基因只能在产免疫球蛋白(κ轻链型)细胞株CA46中表达。当β半乳糖苷酶基因与质粒pcDNA3IgκDTA或pcDNA3IgHDTA共转染时,β半乳糖苷酶基因的表达只在CA46细胞中被抑制。质粒pcDNA3IgκDTA、pcDNA3IgHDTA的表达均能明显抑制CA46细胞的生长,而对照质粒pcDNA3IgκLacZ或pcDNA3IgHLacZ对CA46细胞则无明显作用,并且pcDNA3IgκDTA的抑制作用较pcDNA3IgHDTA更强。结论由免疫球蛋白κ轻链启动子/增强子或免疫球蛋白重链启动子/增强子控制的白喉毒素A链基因的表达能特异性地杀伤产免疫球蛋白(κ轻链)的肿瘤细胞。并且免疫球蛋白κ轻链启动子/增强子较免疫球蛋白重链启动子/增强子有更强的启动转录活性。
Objective To compare the inhibitory effects of immunoglobulin κ light chain promoter / enhancer and immunoglobulin heavy chain promoter / enhancer-controlled diphtheria toxin A chain on the growth of lymphoma cells. Methods The diphtheria toxin A chain gene or bacterial β galactosidase gene was linked with immunoglobulin promoter / enhancer to construct the eukaryotic expression vector of diphtheria toxin A chain pcDNA3IgκDTA, pcDNA3IgHDTA or bacterial β-galactosidase eukaryotic expression vector pcDNA3IgκLacZ , PcDNA3IgHLacZ. The plasmid was transfected into eukaryotic cells with or without immunoglobulin by liposome, the expression of β-galactosidase gene in different cells was detected, and the expression of diphtheria toxin A chain gene Growth inhibition of transfected cells. As a result, the β-galactosidase gene controlled by the immunoglobulin κ light chain promoter / enhancer or the immunoglobulin heavy chain promoter / enhancer can only be expressed in the immunoglobulin (κ light chain type) cell line CA46 . The expression of the beta-galactosidase gene was inhibited only in CA46 cells when the beta galactosidase gene was cotransfected with the plasmid pcDNA3IgκDTA or pcDNA3IgHDTA. The expression of pcDNA3IgκDTA and pcDNA3IgHDTA both inhibited the growth of CA46 cells obviously. However, the control plasmid pcDNA3IgκLacZ or pcDNA3IgHLacZ had no significant effect on CA46 cells, and the inhibitory effect of pcDNA3IgκDTA was stronger than pcDNA3IgHDTA. Conclusions The expression of diphtheria A chain gene controlled by immunoglobulin κ light chain promoter / enhancer or immunoglobulin heavy chain promoter / enhancer can specifically kill tumor cells producing immunoglobulin (κ light chain) . And the immunoglobulin κ light chain promoter / enhancer has a stronger promoter transcriptional activity than the immunoglobulin heavy chain promoter / enhancer.