Stacey K J, Ross I L, Hume D A
Centre for Molecular Biology and Biotechnology, University of Queensland, St Lucia, Australia.
Immunol Cell Biol. 1993 Apr;71 ( Pt 2):75-85. doi: 10.1038/icb.1993.8.
The difficulty of transfecting primary macrophages and macrophage cell lines has meant that relatively few studies on regulation of gene expression have been performed in these cells. This study has optimized an electroporation procedure for the macrophage cell line RAW 264, but shows that introduction of DNA into the cytoplasm of primary macrophages by electroporation is toxic to the cells. It is proposed that this cell death may have a physiological role in defence against certain viral infections which result in accumulation of cytoplasmic DNA. RAW 264 cells were efficiently transfected by electroporation, but electroporated bone marrow derived macrophages (BMM) showed large scale cell death over a period of 12 h. Electroporation without DNA was not toxic and DNase treatment of samples before transfection prevented cell death. The toxicity of DNA was concentration-dependent and sequence-independent. Synthetic, genomic and plasmid DNA all caused cell death. This sensitivity to DNA seems to be distinct from the antiviral state induced by double-stranded RNA and may be part of an uncharacterized viral defence system.
原代巨噬细胞和巨噬细胞系转染的困难意味着在这些细胞中进行的基因表达调控研究相对较少。本研究优化了巨噬细胞系RAW 264的电穿孔程序，但表明通过电穿孔将DNA导入原代巨噬细胞的细胞质对细胞有毒性。有人提出，这种细胞死亡可能在抵御某些导致细胞质DNA积累的病毒感染中具有生理作用。RAW 264细胞通过电穿孔有效地进行了转染，但电穿孔的骨髓来源巨噬细胞（BMM）在12小时内出现大规模细胞死亡。无DNA的电穿孔无毒，转染前对样品进行DNase处理可防止细胞死亡。DNA的毒性呈浓度依赖性且与序列无关。合成DNA、基因组DNA和质粒DNA均导致细胞死亡。这种对DNA的敏感性似乎与双链RNA诱导的抗病毒状态不同，可能是未被表征的病毒防御系统的一部分。
