UVB-WBC INDUCED TOLERANCE IN BONE MARROW TRANSPLANTATION

UVB-WBC 在骨髓移植中诱导耐受

基本信息

批准号：
2735398
负责人：
K J Kao
金额：
$ 20.31万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
1997
资助国家：
美国
起止时间：
1997-07-07 至 2001-06-30
项目状态：
已结题

项目摘要

The long term objective of this proposal is to establish a safe and effective method of using UVB-irradiated peripheral blood leukocytes to induce specific immune tolerance for transplantation of allografts. Prompted by the recent feasibility of preparing UvB- treated platelet concentrates (PC) for patient use and by animal studies suggesting that transfusions of Uv-treated PC can induce partial immune tolerance, we have conducted a series of experiments to characterize immune tolerance induced by transfusions of UvB- irradiated leukocytes in a murine model. Results of our study show that the use of purified UVB-leukocytes with little contamination of plasma and platelets is the key to achieve 100% induction of complete humoral immune tolerance to non-self MHC antigens. However, it is not known whether cellular immune tolerance can be induced by the same approach and applied to allogeneic bone marrow transplantation (BMT) or transplantation of solid allografts. In order to answer these questions, three specific aims are proposed in this application. Specific Aim l is to demonstrate the induction of cellular immune tolerance of UVB-leukocytes. Three approaches will be used: l) to determine whether graft-versus.-host disease (GVHD) induced by allogeneic BMT can be prevented by using bone marrow from donors tolerant to recipient MHC antigens; 2) to investigate whether cytotoxic T cell activity restricted to H-2 antigen of UVB-leukocytes is attenuated after tolerance induction; and 3) to study whether bone marrow (BM) mixed chimerism can be more easily established after sublethal irradiation in mice tolerant to BM donors. Specific Aim 2 is to characterize cellular mechanism of tolerance induction of UVB-leukocytes. We will determine: i) role of class II MHC positive cells in tolerance induction, 2) in vitro cytokine production profile by T cells of tolerant mice, 3) MHC specificity and durability of the induced cellular immune tolerance, and 4) identity of the induced suppressor cells in tolerant mice. Specific Aim 3 is to investigate potential application of UVB-leukocytes in allogeneic BMT to prevent GVHD while preserving graft-versus.-leukemia (GVL) activity. We will investigate whether better GVL activity will result without GVHD in lethally irradiated mice engrafted with BM from tolerant donors, and whether leukemic growth can be prevented in tolerant mice with established BM mixed chimerism. Allogeneic BMT system is chosen for our study mainly for its technical simplicity, and our interest and expertise in BMT. The study proposed herein should enable us to obtain the necessary information for translating tolerance induction b UVB-leukocytes to clinical practice.

该提案的长期目标是建立一个安全、使用UVB照射的外周血的有效方法白细胞诱导移植特异性免疫耐受同种异体移植物。最近制备 UvB- 的可行性促使经处理的血小板浓缩物 (PC)，供患者使用和动物使用研究表明，输注经紫外线处理的 PC 可诱发部分免疫耐受，我们进行了一系列的实验表征由 UvB 输注引起的免疫耐受小鼠模型中受辐射的白细胞。我们的研究结果表明使用污染极少的纯化 UVB 白细胞血浆和血小板的混合是实现100%诱导的关键对非自身 MHC 抗原的完全体液免疫耐受。然而，尚不清楚细胞免疫耐受是否可以通过相同的方法诱导并应用于同种异体骨髓移植（BMT）或实体同种异体移植。在为了回答这些问题，提出了三个具体目标在此应用程序中。具体目标是证明归纳法 UVB-白细胞的细胞免疫耐受性。三种方法将用于： l) 确定是否存在移植物抗宿主病使用骨可以预防同种异体 BMT 诱发的 (GVHD) 来自对受体 MHC 抗原耐受的供体的骨髓； 2）到研究细胞毒性 T 细胞活性是否仅限于 H-2 UVB白细胞抗原在耐受诱导后减弱； 3）研究骨髓（BM）混合嵌合状态是否可以对小鼠进行亚致死照射后更容易建立对骨髓捐赠者具有耐受性。具体目标 2 是表征细胞 UVB白细胞耐受诱导机制。我们将确定： i) II 类 MHC 阳性细胞在耐受性中的作用诱导，2) T 细胞的体外细胞因子产生谱耐受小鼠，3) MHC 特异性和诱导的持久性细胞免疫耐受，以及 4) 诱导的身份耐受小鼠的抑制细胞。具体目标 3 是调查 UVB-白细胞在同种异体 BMT 中的潜在应用预防 GVHD，同时保留移植物抗白血病 (GVL) 活动。我们将研究更好的 GVL 活性是否会在接受致死性辐射的骨髓移植小鼠中没有 GVHD 的结果来自耐受性捐赠者的捐赠，以及是否可以预防白血病的生长在已建立 BM 混合嵌合状态的耐受小鼠中。同种异体选择BMT系统进行我们的研究主要是因为它的技术简单性，以及我们对 BMT 的兴趣和专业知识。研究本文提出的建议应使我们能够获得必要的将耐受诱导 b UVB 白细胞转化为临床实践。