IMMUNOTOXINS IN HUMAN BONE MARROW TRANSPLANTATION

我们的目的是继续我们的基础和临床研究， 免疫毒素（IT）在骨髓移植（BMT）中的作用。 它 将被美国利用。明尼苏达州BMT计划，以治疗各种 其他致命的临床疾病，包括急性和慢性白血病。 在体内使用IT -我们将确定IT的有用性， 疗法 因为半毒素不结合真核细胞，我们将 将它们与单克隆抗体结合并测试其全身免疫的潜力 治疗GVHD，用于促进同种异体BMT中的植入，以及用于 更有效的骨髓移植治疗白血病 我们也会学习IT 使用重组毒素合成，所述重组毒素可具有在体内添加的 均一性的优点，不存在可能影响 归巢和基因改变的能力。 动物实验将 也可用于研究IT向靶细胞的归巢，生物分布， 药代动力学、LD 50和对非靶组织的损伤。 IT的体外使用-我们将继续使用IT清除引起GVHD的细胞 在异基因骨髓移植前从正常供体骨髓中提取 我们将优化我们的 目前的方法使用完整的蓖麻毒素IT通过调查各种IT，如T 细胞亚群定向的IT，以及保留NK细胞的泛T IT。 我们将 强调使用各种体外功能测定作为模型， 体内GVHD。 IT的疗效将在克隆水平上使用 多种表型和功能不同的人T细胞克隆。 我们将继续我们正在进行的临床试验，以确定它将是 最有效的GVHD预防，无需伴随植入 问题 我们将继续在临床上使用IT来清除残留的 自体骨髓移植前骨髓中白血病细胞。 选择IT来清洗T 或B系白血病将基于针对新鲜白血病的IT活性。 在新的集落测定中测量祖细胞并测量IT效力 使用有限稀释的克隆形成测定。 我们会研究如何发展更佳的资讯科技，并决定 抗体亚类、FC部分、表位识别和 亲和力的潜力。每一个IT将评估在许多 纯度、特异性和效力的生物学和生物化学测定。 我们的主要目标是：1）开发IT在体内使用的方案， GVHD、白血病和移植物促进的治疗; 2）优化我们的研究， 目前正在进行临床评价的体外IT方案。

Our purpose is to continue our basic and clinical research determining the usefulness of immunotoxins (IT) in bone marrow transplantation (BMT). It will be utilized by the U. of Minnesota BMT Program to treat a variety of otherwise lethal clinical disorders including acute and chronic leukemia. In vivo use of IT - We will determine the usefulness of IT for systemic therapy. Because hemitoxins do not bind eukaryotic cells, we will link them to monoclonal antibodies and test their potential for systemic treatment of GVHD, for promotion of engraftment in allogeneic BMT, and for more effective conditioning for BMT for leukemia. We will also study IT synthesized using recombinant toxins which may have the added in vivo advantages of homogeneity, absence of carbohydrate residues that may effect homing, and the capacity for genetic alteration. Animal experiments will also be used to study homing of IT to target cells, biodistribution, pharmacokinetics, LD50, and damage to nontarget tissue. Ex vivo use of IT - We will continue using IT to purge GVHD-causing cells from normal donor marrow prior to allogeneic BMT. We will optimize our current approach using intact ricin IT by investigating various IT, e.g. T cell subpopulation directed IT, and pan-T IT sparing NK cells. We will emphasize the use of various in vitro functional assays as models of in vivo GVHD. Efficacy of IT will be determined at the clonal level using a variety of phenotypically and functionally different human T cell clones. We will continue our ongoing clinical trials to determine which IT will be the most efficacious for GVHD prophylaxis without concomitant engraftment problems. We will continue the clinical use of IT to purge residual leukemia cells from BM prior to autologous BMT. Choice of IT for purging T or B-lineage leukemia will be based on IT activity against fresh leukemic progenitor cells measured in novel colony assays and IT potency measured using clonogenic assays by limiting dilution. We will study ways of producing better IT. We will determine the role of differences in antibody subclass, FC portion, epitope recognition, and affinity for the potency of IT. Each IT will be evaluated in numerous biological and biochemical assays for purity, specificity, and potency. Our major goals are 1) to develop protocols for the in vivo use of IT in the treatment of GVHD, leukemia, and graft promotion; 2) to optimize our in vitro IT protocols that are currently undergoing clinical evaluation.