Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
Mol Ther. 2010 Apr;18(4):775-84. doi: 10.1038/mt.2010.1. Epub 2010 Feb 9.
Liposome:DNA is a promising gene therapy vector. However, this vector can elicit a systemic inflammatory response syndrome (SIRS). Prior reports indicate that liposome:DNA vectors activate Toll-like receptor (TLR)9. We hypothesized that liposome:DNA vectors also activate the cytosolic DNA-sensing pathway, which signals via interferon (IFN) regulatory factor (IRF)3. To test this, we treated dendritic cells (DCs) with liposome:DNA in vitro and found that IRF3 was phosphorylated independent of TLR9. To test the contribution of this pathway in vivo, we injected a liposome:DNA vector into wild-type (WT), TLR9-knockout (KO), IRF3-KO, and TLR9-IRF3-double-KO (DKO) mice. WT mice exhibited a systemic inflammatory response, evidenced by elevations in serum cytokines, serum enzyme changes indicating organ damage, hypothermia, and mortality. The cytokine response was reduced in TLR9-KO, IRF3-KO, and TLR9-IRF3-DKO mice and all three groups survived. We found that IFN-gamma-KO mice that receive liposome:DNA had a reduced cytokine response and 100% survival. CD11c(+) and NK1.1(+) cells produced IFN-gamma and depleting CD11c(+) cells reduced the cytokine response in mice injected with liposome:DNA. These findings may facilitate the development of immunologically inert gene therapy vectors and may provide general insight into the mechanisms of SIRS.
DNA 是一种很有前途的基因治疗载体。然而，这种载体可能会引发全身炎症反应综合征（SIRS）。先前的报告表明，脂质体：DNA 载体可激活 Toll 样受体（TLR）9。我们假设脂质体：DNA 载体也会激活细胞质 DNA 感应途径，该途径通过干扰素（IFN）调节因子（IRF）3 发出信号。为了验证这一点，我们在体外用脂质体：DNA 处理树突状细胞（DC），发现 IRF3 的磷酸化不依赖于 TLR9。为了测试该途径在体内的作用，我们将脂质体：DNA 载体注射到野生型（WT）、TLR9 敲除（KO）、IRF3-KO 和 TLR9-IRF3 双敲除（DKO）小鼠体内。WT 小鼠表现出全身炎症反应，表现为血清细胞因子升高、血清酶变化表明器官损伤、体温过低和死亡率增加。TLR9-KO、IRF3-KO 和 TLR9-IRF3-DKO 小鼠的细胞因子反应降低，所有三组均存活。我们发现，接受脂质体：DNA 的 IFN-γ-KO 小鼠的细胞因子反应降低，存活率为 100%。CD11c(+) 和 NK1.1(+) 细胞产生 IFN-γ，并且用 CD11c(+) 细胞耗竭可降低注射脂质体：DNA 的小鼠的细胞因子反应。这些发现可能有助于开发免疫惰性基因治疗载体，并为全身炎症反应综合征的机制提供一般见解。
