Virus Specific CTL following T cell depleted SCT

T 细胞耗尽 SCT 后的病毒特异性 CTL

• 批准号: 7017794
• 负责人: KENNETH G LUCAS
• 金额: $ 24.66万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-12 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7017794
• 关键词: Epstein Barr virus; Retroviridae; antigen presentation; antigen presenting cell; clinical research; cytomegalovirus; cytotoxic T lymphocyte; cytotoxicity; flow cytometry; gene deletion mutation; graft versus host disease; helper T lymphocyte; hematopoietic tissue transplantation; homologous transplantation; human subject; polymerase chain reaction; stem cell transplantation; transplantation immunology; tumor antigens

DESCRIPTION (provided by applicant): T cell depletion (TCD) of allogeneic stem cell transplants (SCT) dramatically reduces the risk of graft vs host disease (GVHD) but results in a heightened risk for infectious complications, two of the most serious being Epstein Barr virus (EBV) induced lymphoproliferative disease and cytomegalovirus (CMV) infection. Previous studies have shown that cytotoxic T lymphocytes can be cultured and infused into SCT recipients resulting in antigen specific immune reconstitution, but this can be impractical due to the need of expanding CTL with separate antigen presenting cells. Preliminary studies have demonstrated the feasibility of retroviral transduction of B lymphoblastoid cell lines (BLCL) to achieve expression of CMV pp65, and stimulation with BLCL expressing pp65 results in expansion of CTL recognizing both CMVpp65 and EBV antigens. In this proposal, we will compare the clinical, immunologic, and virologic effects of prophylactic CMV/EBV specific CTL in recipients of allogeneic, TCD SCT with a control group of TCD SCT patients randomized to not receive CTL. CD4 and CD8 antigen specific immune reconstitution (CTL precursor frequencies) and CMV and EBV DNA levels (by real time PCR) will be compared in these groups at intervals post-transplant. We will determine which CMVpp65 epitopes are immunodominant in stem cell donors using recombinant vaccinia encoding pp65 deletion mutations, and then the exact epitopes will be determined using synthetic peptides pulsed onto APC. Dominant epitopes of the CTL donors will be compared with those found in CTL recipients post-infusion, to determine whether immunodominant epitopes recognized by the donor are retained in the recipient, and if not, which epitopes are most relevant post-transplant. Also of interest are the types of effector cells and the dynamic changes in CD4 and CD8 CMV specific T cells during CMV reactivation in recipients of CTL and the control group. These studies will determine the impact on viral reactivation and immune reconstitution of prophylactic antigen-specific CTL and will serve as a groundwork for extending this system of antigen presentation and T cell expansion to other pathogens as well as tumor antigens in the future.

描述（由申请人提供）：同种异体干细胞移植（SCT）的T细胞耗竭（TCD）大大降低了移植物与宿主疾病（GVHD）的风险，但导致感染性并发症的风险增加，其中两个最严重的是Epstein Barr病毒（EBV）诱导的淋巴结疾病和cymphoprolifecret（Cmphoprofication）（CMPHARVIRED）（CMPHERICTAID）（CMPHERICTAID）（CMPHERED）（CMPHERED）（CMPHERICTORAID（CMPHERED）。先前的研究表明，可以将细胞毒性T淋巴细胞培养并注入导致抗原特异性免疫结构的SCT受体中，但是由于需要通过单独的抗原呈现细胞扩展CTL，因此这可能是不切实际的。初步研究表明，B淋巴细胞细胞系（BLCL）逆转录病毒转导的可行性以实现CMV PP65的表达，并且用表达PP65的BLCL刺激会导致CTL识别CMVPP65和EBV抗原的CTL扩展。在此提案中，我们将比较预防性CMV/EBV特异性CTL在同种异体，TCD SCT受体中的临床，免疫和病毒学作用与随机分配到未接受CTL的TCD SCT患者的对照组。 CD4和CD8抗原特异性免疫重建（CTL前体频率）以及CMV和EBV DNA水平（通过实时PCR）将在移植后的间隔中比较这些组。我们将使用编码PP65缺失突变的重组疫苗在干细胞供体中确定哪些CMVPP65表位是免疫主导的，然后使用脉冲到APC上的合成肽确定确切的表位。将将CTL供体的主要表位与输入后的CTL受体中发现的表位相比，以确定供体认可的免疫主导表位是否保留在受体中，如果没有保留，如果没有，则表位是最相关的后置植物后置植物。同样令人感兴趣的是效应细胞的类型以及CTL和对照组的受体中CMV重新激活过程中CD4和CD8 CMV特异性T细胞的动态变化。这些研究将确定对预防性抗原特异性CTL病毒重新激活和免疫重建的影响，并将作为扩展这种抗原呈递系统和T细胞扩展到其他病原体以及未来肿瘤抗原的基础。