McClane S J, Chirmule N, Burke C V, Raper S E
Institute for Human Gene Therapy and Harrison Department of Surgical Research, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
Hum Gene Ther. 1997 Dec 10;8(18):2207-16. doi: 10.1089/hum.1997.8.18-2207.
The pancreas is an ideal organ for adenoviral gene therapy because of the high level of gene transfer that can be achieved and because of the many diseases that can potentially be treated using this technology. In this report, we characterize the immune response to direct pancreatic injection of adenovirus and we overcome some of the limitations it imposes by using immunosuppression. Direct injection of recombinant adenovirus into the pancreas leads to the production of neutralizing antibodies and to sensitized splenocytes which engage in increased cytotoxic, lymphoproliferative, and cytokine release activity when reexposed to adenovirus. Transgene expression is transient and the vector cannot be readministered. Deletion of CD4+ T helper cells improves expression over time (40% of pancreatic cells express transgene at day 28 vs. 5% in controls), and allows the vector to be readministered in the pancreas, albeit, inefficiently, when compared to naive animals. Similarly, blockade of CD40 ligand, which preserves the CD4+ T helper cell population, also improves expression over time (30% of pancreatic cells express transgene at day 28), and allows the vector to be readministered. With both approaches, neutralizing antibodies are decreased and the remaining splenocytes do not engage in activated immune responses. Thus, local delivery of the adenoviral vector induces a systemic response that prevents pancreatic readministration, even with direct injection. Blockade of CD40 ligand and T helper cell depletion are transient regimens that induce systemic immunosuppression. Until the development of newer strategies that selectively suppress adenoviral immune responses, these are viable alternatives for enhancement of pancreatic adenoviral delivery.
胰腺是腺病毒基因治疗的理想器官，因为可以实现高水平的基因转移，且利用该技术有多种疾病可能得到治疗。在本报告中，我们描述了对胰腺直接注射腺病毒后的免疫反应，并通过免疫抑制克服了其所带来的一些局限性。将重组腺病毒直接注射到胰腺中会导致中和抗体的产生以及致敏脾细胞的出现，这些脾细胞在再次接触腺病毒时会表现出增强的细胞毒性、淋巴细胞增殖和细胞因子释放活性。转基因表达是短暂的，且不能再次给药。删除CD4 +辅助性T细胞可随时间改善表达情况（第28天时40%的胰腺细胞表达转基因，而对照组为5%），并允许在胰腺中再次给药，尽管与未接触过病毒的动物相比效率较低。同样，阻断CD40配体（可保留CD4 +辅助性T细胞群体）也会随时间改善表达情况（第28天时30%的胰腺细胞表达转基因），并允许再次给药。采用这两种方法，中和抗体都会减少，剩余的脾细胞也不会参与激活的免疫反应。因此，即使是直接注射，腺病毒载体的局部递送也会引发全身性反应，从而阻止在胰腺中的再次给药。阻断CD40配体和T辅助细胞耗竭是诱导全身性免疫抑制的短暂方案。在开发出选择性抑制腺病毒免疫反应的更新策略之前，这些是增强胰腺腺病毒递送的可行替代方法。
