Gene therapy for induction of immunological tolerance in organ allografts

(背景)基因转移方法有可能将免疫抑制分子直接引入同种异体移植物，从而限制传统免疫抑制治疗对受体的全身副作用。目的分析腺病毒介导的白介素4基因转移在大鼠肾移植模型中的作用及其机制。(材料与方法)BN大鼠移植肾分别与Adex1CAmIL4或AxCALacZ(RIKEN DNA Bank)在4℃温育1.5、24、48、72h(体外)，或/和移植到LEW受体。腺病毒载体用4C生理盐水或UW液灌流，移植肾保存在4C生理盐水(1.5h)或UW液(24~72h)中。(结果)1.体外模型保存24小时后检测到β-GAL，1.5小时未检测到。移植后第2天/第7天，移植肾内未见β-GAL染色。2.在体外保存中，Adex1CAmIL4灌流组的移植肾(1.5h-72hIL4)均有IL4表达，而冷生理盐水灌注组在任何保存时间内均未检测到IL4的表达。3.Adex1CAmIL4基因转移后24小时移植肾的组织学损伤较移植后7天保存1.5小时的移植肾明显减轻。(结论)腺病毒介导的IL-4基因治疗以24小时保存为宜。保持1.5h。在移植后的早期(0-2天)，IL-4的适当表达可能是重要的。在移植环境中，基因转移的“最佳方式”还有待进一步研究。

(Background) Gene transfer approach has the potential to introduce immunosuppressive molecules directly into the allograft, which in turn should limit systemic side effects of conventional immunosuppressive therapy to recipients. (Aim) To analyze the efficacy and putative mechanisms of adenoviral-mediated IL4 gene transfer in rat kidney transplant model. (Material ＆ Method) Renal allografts (BN rat) were perfused in-situ with Adex1CAmIL4 or AxCALacZ (RIKEN DNA Bank, respectively) incubated at 4C for 1.5, 24, 48, 72h (ex-vivo), or/and transplanted to LEW recipients. Adenovirus vector was perfused with 4C saline or UW solution, and renal grafts were preserved in 4C saline (1.5h) or UW solution (24-72h). (Results) 1. β-gal was detected after 24h preservation, but not 1.5h in ex-vivo model. After transplantation, there was mo staining of β-gal in renal allograft at day2/day7. 2. In ex-vivo preservation, IL4 was expressed in all of renal grafts (1.5h-72h) with Adex1CAmIL4 perfusion, even though it was not detected in control group perfused with cold saline in any preserved term. 3. Histological damage of renal allografts maintained for 24h after Adex1CAmIL4 gene transfer were diminished as compared with 1.5h preserved grafts at day7 after transplantation. (Conclusion) 24h preservation was prefer to induce immunosuppressive effects of Adenovirus-mediated IL4 gene therapy as compared. with 1.5h maintaining. It seems that appropriate expression of IL4 might be important at the early phase (day0-2) after transplantation. Further study will be necessary to inquire "optimal way" of gene transfer in transplant setting.