XENOGENEIC THYMIC TRANSPLANTATION AS AN ADJUNCT TO TREATMENT OF AIDS

异种胸腺移植作为艾滋病治疗的辅助手段

• 批准号: 6591306
• 负责人: M ROSENZWEIG
• 金额: $ 11.11万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-01 至 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6591306
• 关键词: AIDS; animal tissue; communicable diseases; immunology; inflammation; lymphatic system; transplantation; virus

The goal of this project is to determine the feasability of xenogeneic pig thymus to engraft in an SIV infected macaque, and to determine if this has any impact on T cell reconstitution The initial aim was to establish baseline assays to determine the degree of immunosupression as a result of SIV We have conducted comprehensive analysis to determine the optimal in vitro conditions to determine both alloantigen and xenoantigen responses in macaques Our data demonstrate poor to absent xeno and allo- responses in macaques with advanced SIV disease, as well as 1-2 log reduction in the proliferation response to lectin Based on the poor in vitro proliferative responses we wished to examine whether pig thymic tissue might engraft in SIV-infected macaques without any conditioning We therefore performed transplants of pig thymic tissue in 2 SIV-infected macaques with advanced disease (CD4<200 mm3) Biopsy of the transplant site at 30 days revealed lymphoid aggrega tes of rhesus T cells in both animals, with only minimal inflammatory changes outside the lymphoid aggregates No evidence for engraftment of pig thymic tissue was observed (negative results for pig cytokeratin, MHC class I, MHC class II, and CD2) These results suggest that even SIV-infected animals with advanced disease are able to mount sufficient immune responses to reject swine thymus Due to our inability to achieve engraftment of pig thymus in SIV infected macaques in the absence of conditioning (see below), we altered our experimental design to include a conditioning protocol, namely cyclophosphamide anti-thymocyte globulin (ATG) and cyclosporine In the first animal examined, we achieved 99% depletion of peripheral T cells (CD3+) following ATG treatment, but the CD3+ count rapidly returned to baseline within 3 days The second animal received 3 additional days of ATG, but we observed poor T cell depletion only (90%) depletion after 6 days of ATG Both animals received pig thymus in both the omentum and quadriceps Antiretroviral therapy as well as PCP prophylaxis was continued Biopsies of the quadriceps muscle transplant sites at 1 and 3 months demonstrated profound infiltration of rhesus CD3+CD8+ T cells into the area, with no evidence for engraftment as detected by immunohistochemistry for cytokeratin as well as pig-specific antigens We concluded that we had a low level engraftment, but no clear functional thymus was detected A clear problem in data interpretation is that the animals both had detectable thymus in the mediastinum at autopsy, so the rebound of naive T cells cannot be used as an indicator of engraftment and function, this will be addressed by performing thymectomy prior to SIV-infection in subsequent animals

本项目的目标是确定 异种猪胸腺移植入SIV感染的猕猴， 确定这是否对T细胞重建有任何影响。 目的是建立基线分析，以确定 免疫抑制由于SIV我们已经进行了全面的 分析以确定最佳体外条件，以确定 猕猴的同种异体抗原和异种抗原应答 在猕猴中表现出差的或不存在的异种和同种异体反应， 晚期SIV疾病以及 基于凝集素的体外增殖反应差 增殖反应我们希望检查猪胸腺组织是否 可以在没有任何条件的情况下移植到SIV感染的猕猴体内。 因此，在2只SIV感染的猪中进行了猪胸腺组织移植， 患有晚期疾病的猕猴（CD4<200 mm3）移植物活检 在30天的研究中， 这两种动物，只有最小的炎症变化外， 淋巴聚集体没有猪胸腺组织植入的证据 观察到（猪细胞角蛋白、MHC I类、MHC II类和CD 2）这些结果表明，即使是SIV感染， 患有晚期疾病的动物能够获得足够的免疫力， 拒绝猪胸腺的反应由于我们无法实现 猪胸腺在SIV感染的猕猴中的移植， 条件反射（见下文），我们改变了实验设计， 包括调节方案，即环磷酰胺 抗胸腺细胞球蛋白（ATG）和环孢菌素在第一只动物中 检查，我们实现了99%的外周T细胞（CD3+）耗竭 ATG治疗后，但CD3+计数迅速恢复至 第二只动物接受另外3天的 ATG，但我们观察到T细胞耗竭仅差（90%）， ATG 6天。 股四头肌抗逆转录病毒治疗以及PCP预防， 在第1和第2天继续对股四头肌移植部位进行活检， 3个月显示恒河猴CD3+CD8+ T细胞的深度浸润 进入该地区，没有证据表明植入检测 细胞角蛋白和猪特异性抗原免疫组织化学 我们的结论是，我们有一个低水平的植入，但没有明确的 检测到功能性胸腺数据解释中的一个明显问题 这两种动物的纵膈中都有可检测到的胸腺， 尸检，所以幼稚T细胞的反弹不能被用作 植入和功能指标，这将通过 在随后的动物中SIV感染之前进行胸腺切除术