Benihoud K, Salone B, Esselin S, Opolon P, Poli V, Di Giovine M, Perricaudet M, Saggio I
Dipartimento di Genetica e Biologia Molecolare, Universita' La Sapienza, Rome, Italy.
J Gene Med. 2000 May-Jun;2(3):194-203. doi: 10.1002/(SICI)1521-2254(200005/06)2:3<194::AID-JGM102>3.0.CO;2-5.
The major concern for the use of adenoviral vectors for gene therapy is the viral-induced immune response that has been shown to be responsible for short-term transgene expression and inefficient viral readministration. In vivo studies and clinical trials with recombinant adenovirus have suggested a role for interleukin 6 (IL-6) in the inflammatory reaction that follows Ad-infection. IL-6 plays an important role in the acute-phase innate response, in the differentiation of B-cells and in the activation of the Th2 cell subsets.
To clarify the role of IL-6 in the immune response to Ad-vectors, we used IL-6 knock-out mice (IL-6 -/- ). E1/E3 deleted recombinant adenoviruses encoding reporter genes were administered to wild type or IL-6-/- mice; transgene expression kinetics and immune response were analyzed.
Acute phase protein production was significantly diminished in IL-6 -/- mice after adenoviral injection. No significant difference between wild type and knock-out animals in the level or the nature of leucocyte recruitment in the liver was detectable. A minor decrease in the IgG response to Ad-recombinants was observed in knock-out mice. Gene transfer efficiency, both in terms of levels and duration of transgene expression, were comparable in IL-6+/+ and IL-6-/- mice. An increase in IL-1beta and tumor necrosis factor-alpha (TNF-alpha) levels was observed in the sera of IL-6 -/- mice as compared to wild type animals: this phenomenon represents a possible compensatory mechanism for the establishment of the immune phenotype observed in mutant mice.
IL-6 plays a role in the acute phase response to adenoviral vectors. Nevertheless, possibly due to a compensatory mechanism exerted by other cytokines, the antibody and cellular responses to adenoviruses are very similar in wild type and IL-6 -/- mice.
使用腺病毒载体进行基因治疗的主要问题是病毒诱导的免疫反应，该反应已被证明与短期转基因表达及病毒再给药效率低下有关。重组腺病毒的体内研究和临床试验表明，白细胞介素6（IL-6）在腺病毒感染后的炎症反应中发挥作用。IL-6在急性期固有反应、B细胞分化及Th2细胞亚群激活中起重要作用。
为阐明IL-6在对腺病毒载体免疫反应中的作用，我们使用了IL-6基因敲除小鼠（IL-6 -/- ）。将编码报告基因的E1/E3缺失重组腺病毒给予野生型或IL-6 -/- 小鼠；分析转基因表达动力学和免疫反应。
腺病毒注射后，IL-6 -/- 小鼠急性期蛋白产生显著减少。在肝脏白细胞募集水平或性质方面，野生型和基因敲除动物之间未检测到显著差异。在基因敲除小鼠中观察到对腺病毒重组体的IgG反应略有下降。在转基因表达水平和持续时间方面，IL-6+/+和IL-6 -/- 小鼠的基因转移效率相当。与野生型动物相比，在IL-6 -/- 小鼠血清中观察到IL-1β和肿瘤坏死因子-α（TNF-α）水平升高：这种现象代表了在突变小鼠中观察到的免疫表型建立的一种可能的补偿机制。
IL-6在对腺病毒载体的急性期反应中起作用。然而，可能由于其他细胞因子发挥的补偿机制，野生型和IL-6 -/- 小鼠对腺病毒的抗体和细胞反应非常相似。
