Jooss K, Yang Y, Wilson J M
Institute for Human Gene Therapy, University of Pennsylvania, Philadelphia, USA.
Hum Gene Ther. 1996 Aug 20;7(13):1555-66. doi: 10.1089/hum.1996.7.13-1555.
Immune responses to adenovirus-mediated gene transfer contribute to the problems of transient recombinant gene expression, inflammation, and difficulties with vector readministration. Activation of CD4+ T cells is required for full realization of effector function of both CD8+ T cells (i.e., cytotoxic T cells) and B cells (i.e., neutralizing antibody). We evaluate in this study the effectiveness of a short course of high-dose cyclophosphamide to block immune responses in mice administered vector into lung and liver of C57BL/6 mice. Administration of cyclophosphamide with vector directed to liver blocked activation and mobilization of both CD4+ and CD8+ T cells. As a result, transgene expression was prolonged, inflammation was reduced, and, at the higher doses of cyclophosphamide, formation of neutralizing antibody was prevented and the vector was successfully readministered. Similar studies in the lung demonstrated an effective blockade of T and B cell responses. In contrast to the liver, where it was easier to stabilize transgene expression than to prevent neutralizing antibody, cyclophosphamide prevented the formation of neutralizing antibodies at all doses in the lung, whereas stabilization of transgene expression was only achieved at the highest dose. These experiments begin to define the parameters by which cyclophosphamide could be used as an adjunct in gene therapy.
对腺病毒介导的基因转移的免疫反应导致了瞬时重组基因表达、炎症以及载体再次给药困难等问题。CD4+ T细胞的激活是CD8+ T细胞（即细胞毒性T细胞）和B细胞（即中和抗体）充分发挥效应功能所必需的。在本研究中，我们评估了短疗程高剂量环磷酰胺对C57BL/6小鼠肺和肝内注射载体后的免疫反应的阻断效果。将环磷酰胺与靶向肝脏的载体一起给药可阻断CD4+和CD8+ T细胞的激活和动员。结果，转基因表达得以延长，炎症减轻，并且在较高剂量的环磷酰胺作用下，中和抗体的形成被阻止，载体得以成功再次给药。在肺部进行的类似研究表明T和B细胞反应被有效阻断。与肝脏不同，在肝脏中稳定转基因表达比阻止中和抗体更容易，而环磷酰胺在肺部所有剂量下均能阻止中和抗体的形成，而转基因表达的稳定仅在最高剂量下才能实现。这些实验开始确定环磷酰胺可作为基因治疗辅助手段的参数。
