ANTILEUKEMIC EFFECT OF IRRADIATED ALLOGENEIC LYMPHOCYTES

描述：（申请人的摘要）移植物抗宿主病（GVHD）， 异基因骨髓移植（BMT）受者可以通过以下方法预防 同种异体移植物的T细胞耗竭（TcD），但这会导致 移植排斥和白血病复发的频率。 申请人已经 研究了使用辐射同种异体白细胞作为一种新的方法 支持移植并保持供体淋巴细胞的GVL效应 不会引起移植物抗宿主病 在7.5戈伊辐射下确定的初步工作 抑制同种异体T细胞的增殖潜力，同时保留 它们的体外细胞毒性和它们促进植入的能力， 体内TcD同种异体骨髓。 辐射同种异体的TcD 脾细胞消除了移植物促进活性。 多次喷射 照射的同种异体脾细胞增加了无白血病的比率， 同种异体TcD骨髓和同种异体TcD骨髓移植小鼠的存活率 与同种异体TcD BMT和白血病接受者相比， 一个人 这些研究的总体假设是， 白细胞提供针对宿主不同短期同种异体反应性 白血病细胞和促进供体造血移植而不产生 BMT环境中的GVHD。 辐射的可能作用机制 同种异体白细胞包括增强的对正常和 白血病宿主造血细胞;产生细胞因子介导 对宿主型细胞的抗增殖或致细胞病变作用;或 增强共同施用的未照射或未照射的抗肿瘤药物的同种异体反应性， 抗辐射供体细胞 为了研究这些机制， 三个具体目标。 在第一个具体目标中，申请人将确定 负责移植物促进和GVL活性的细胞 辐射的同种异体淋巴细胞。 他将使用富集的脾细胞， T或NK细胞群耗尽的突变型SCID和米色小鼠， T细胞和NK细胞，以确定这些细胞是否介导 促进移植和GVL效应。 辐照的抗白血病活性 将使用共移植有以下细胞的受体测试同种异体脾细胞： 一种同源性骨髓性白血病系或MRP-8/Bcl-2/LPR转基因小鼠， 会自发地发展成骨髓性白血病 在第二个具体目标中， 申请人将确定抗白血病的分子机制 受照射白细胞的活性测试细胞的贡献 接触依赖性细胞溶解与细胞病变或细胞抑制剂的释放 可溶性因子。 在第三个具体目标中， 申请人将测试是否通过以下方法引发同种异体脾细胞的供体 同种异体免疫或细胞因子增强移植物促进和GVL 辐射淋巴细胞的活性。 多次注射辐照的 白细胞将用于建立初始植入;随后 输注未经辐照的供体白细胞将用于根除 当发生急性GVHD的风险降低时，残留的宿主型细胞。

DESCRIPTION: (Applicant's Abstract) Graft-versus-host disease (GVHD) in allogeneic bone marrow transplantation (BMT) recipients can be prevented by T-cell depletion (TcD) of the allograft, but this results in increased frequencies of graft rejection and leukemia relapse. The applicant has investigated the use of irradiated allogeneic leukocytes as a novel method to support engraftment and preserve the GVL effect of donor lymphocytes without causing GVHD. Preliminary work established at 7.5 Gy radiation inhibits the proliferative potential of allogeneic T-cells while preserving their in vitro cytotoxicity and their capacity to facilitate engraftment by TcD allogeneic bone marrow in vivo. TcD of irradiated allogeneic splenocytes eliminated the graft facilitating activity. Multiple injection of irradiated allogeneic splenocytes increased the rate of leukemia-free survival in mice transplanted with allogeneic TcD bone marrow and congenic leukemia cells compared to recipients of allogeneic TcD BMT and leukemia alone. The overall hypothesis of these studies is that irradiated donor leukocytes provide differential short-term allo-reactivity against host leukemia cells and promote donor hematopoietic engraftment without producing GVHD in the BMT setting. Possible mechanisms of action of irradiated allogeneic leukocytes include enhanced cytolytic activity against normal and leukemic host hematopoietic cells; production of cytokines that mediate an anti-proliferative or cytopathic effect against host-type cells; or enhancement of the allo-reactivity of co-administered non-irradiated or radio-resistant donor cells. To investigate these mechanisms are proposed three specific aims. In the first specific aim, the applicant will identify the cells responsible for the graft-facilitating and GVL activity of irradiated allogeneic lymphocytes. He will use splenocytes enriched or depleted for T or NK-cell populations and mutant SCID and beige mice lacking T and NK cells respectively to determine whether these cells mediate the graft-facilitating and GVL effect. The anti-leukemia activity of irradiated allogeneic splenocytes will be tested using recipients co-transplanted with a congenic myeloid leukemia line or mrp-8/bcl-2/lpr transgenic mice that spontaneously develop myeloid leukemia. In the second specific aim, the applicant will determine the molecular mechanisms of the anti-leukemia activity of irradiated leukocytes testing the contribution of cell contact-dependent cytolysis vs. the release of cytopathic or cytostatic soluble factors by irradiated cells. In the third specific aim, the applicant will test whether priming donors of allogeneic splenocytes by allo-immunization or with cytokines enhances the graft facilitating and GVL activity of irradiated lymphocytes. Multiple injections of irradiated leukocytes will be used to establish initial engraftment; subsequent infusion of non-irradiated donor leukocytes will be used to eradicate residual host-type cells when the risk for developing acute GVHD is reduced.