摘要
目的探讨基于淋巴细胞毒性相关抗原4-抗体重组腺病毒(AdCTLA4-Ig)的非清髓性方案在造血干细胞嵌合体诱导复合组织异体移植免疫耐受中的作用。方法以近交系Brown Norway(RT1^n)大鼠为供体,Lewis(RT1^1)大鼠为受体。以后肢移植当天记为day0。实验分4组,A组:受体直接给予同种异体后肢移植,移植前不进行非清髓性预处理,移植后连续100d,每天仅给予低剂量环胞素A(CsA),8mg/kg腹腔注射。B组:受体先给予非清髓性预处理,移植前第33天至移植后第100天,每日用免疫抑制剂三联方案腹腔注射雷帕霉素(RAPA,0.2mg/kg)+麦考(MMF,20mg/kg)+甲泼尼龙(MP,10mg/kg),在移植当日及移植前及移植后第30天分3次尾静脉注射AdCTLA4-Ig(5×10^9PFU/d),后肢移植前30d接受单次3Gy(照射率0.5Gy/min)低强度全身照射,不予骨髓移植(BMT)。C组:受体预处理方案同B组,移植前30d,在低强度全身照射后4h内给予单次尾静脉注射供体骨髓细胞(100×10^6cells)。D组:受体预处理方案及BMT方法同C组,但大鼠后肢移植供体为第三方动物WF大鼠。在后肢移植后第100天开始,B、C及D组均停止免疫抑制剂三联方案,每日仅给予低剂量CsA(8mg/kg),连续100d,直至大鼠后肢移植物发生排异反应而坏死。通过外周血嵌合率检测、移植物抗宿主病检测、后肢移植物存活情况观察、移植物组织病理学检查与评价及混合淋巴细胞反应对免疫耐受状态进行分析评价。结果C组外周血嵌合率移植当日为(38.8±10.6)%,并长期保持稳定,移植后第300天为(29.3±11.9)%,均未发生移植物抗宿主病,停止免疫抑制剂三联方案后移植物存活〉200d,A、B、D组均发生免疫排异,后肢移植物分别存活(8±2)、(18±3)及(20±2)d,与C组相比,差异有统计学意义(P〈0.01)。C组移植物病理学检查显示无毛囊炎及血管周围炎等慢性免疫排异现象,混合淋巴细胞反应显示为供体特异性免疫耐受状态。结论基于AdCTLA4-Ig的非清髓性BMT方案可以诱导长期稳定的造血干细胞嵌合体状态,并可以诱导受体对大鼠后肢移植物的供体特异性部分性免疫耐受。
Objective To investigate a non-toxic AdCTLA4-Ig-based protocol for non-myeloablative allogeneic hematopoietic cell transplantation to induce donor-specific tolerance to hind limb allografts in rats. Methods Fully mismatched, 4 to 8 week old Brown Norway ( RT1^n ) and Lewis ( RT1^1 ) rats were used as cell/organ donors and recipients, respectively. Recipients were treated with AdCTLA4:Ig(5 x 109 PFU, day - 30,0,30) , standard immunosuppressive therapy( MP : 10 mg· kg^-1 · d^-1, MMF : 20 mg· kg^-1 · d^-1 , RAPA: 0. 2 mg · kg^-1 · d^-1 ;day -33-100), soon after total body irradiation (3Gy, day -30) and donor bone marrow ( 100 × 10^6, day - 30) transplantation (BMT). Thirty days after BMT, chimeric animals received hind limb transplantations. And 100 days after hind limb transplantations, immunosuppressive therapy was changed for low-dosed CsA (8 mg · kg^-1 · d^-1 ,day 100-) ,until the allografts were rejected. Results In Group C, hematopoietic chimerism was (38. 8 ± 10. 6) % at day 0, and was stable (29. 3 ± 11.9) % at 330 days post-BMT. There was no graft versus host disease in both Group C and Group D. When the standard immunosuppressive therapy was stopped and changed for low-dosed CsA, chimeric recipients (Lewis,RT11) permanently accepted ( 〉 200 days ) donor specific (Brown Norway, RT1 ^n) hind limb allografts in Group C, yet rapidly rejected in Group A ( 8 ± 2 ) d, Group B ( 18 ± 3 ) d and in Group C (20 ± 2)d. Lymphocytes of graft tolerant animals' demonstrated hyporesponsiveness in mixed lymphocyte cultures in a donor-specific manner in Group C. Tolerant graft histology showed no obliterative arteriopathy or chronic rejection. Conclusion The AdCTLAd-Ig based conditioning regimen with donor BMT produce stable mixed chimerism and induce donorspecific tolerance to hind limb allografts.
出处
《中华外科杂志》
CAS
CSCD
北大核心
2009年第12期937-940,共4页
Chinese Journal of Surgery
基金
国家自然科学基金资助项目(30672189)
关键词
细胞毒性试验
免疫
嵌合体
移植物
非清髓性
Cytotoxicity tests,immunologic
Chimera
Transplants
Non-myeloablative