UVB-WBC INDUCED TOLERANCE IN BONE MARROW TRANSPLANTATION

这项提议的长期目标是建立一个安全和 利用UVB照射外周血的有效方法 白细胞诱导移植特异性免疫耐受 同种异体移植物。由于最近制备UVB的可行性- 病人用和动物用的经处理的浓缩血小板(PC) 研究表明，输注经紫外线处理的PC可以诱导 为了部分免疫耐受，我们进行了一系列实验 研究输注UVB诱导的免疫耐受的特征 照射小鼠模型中的白细胞。我们的研究结果表明 使用污染很小的纯化UVB-白细胞 血浆和血小板是实现100%诱导的关键 对非自身MHC抗原的完全体液免疫耐受。 然而，目前尚不清楚细胞免疫耐受是否可以 同样的方法诱导并应用于异基因骨髓 移植(BMT)或同种异体实体移植。在……里面 为了回答这些问题，我们提出了三个具体目标 在此应用程序中。L的具体目的是演示归纳 UVB-白细胞细胞免疫耐受的研究。三种方法 将用于：L)确定移植物抗宿主病 同种异体骨髓移植诱导的移植物抗宿主病(GVHD)可通过用骨来预防 耐受MHC抗原的供者骨髓；2)至 研究细胞毒T细胞活性是否仅限于H-2 诱导耐受后，UVB-白细胞抗原减弱； 3)研究骨髓混合嵌合体能否 更容易在亚致死剂量照射后建立小鼠 对骨髓捐赠者的宽容。具体目标2是描述细胞的特征 中波紫外线诱导白细胞耐受的机制。我们会 确定：I)第II类MHC阳性细胞在耐受中的作用 2)T细胞体外细胞因子产生谱 耐受小鼠，3)MHC诱导的特异性和持久性 细胞免疫耐受，以及4)诱导的 耐受小鼠体内的抑制细胞。具体目标3是调查 UVB-白细胞在异基因骨髓移植中的潜在应用 在保护移植物抗白血病(GVL)的同时预防GVHD 活动。我们将调查更好的GVL活动是否会 无GVHD的BM植入致死性照射小鼠的结果 来自宽容的捐赠者，以及是否可以防止白血病的增长 在已建立BM混合嵌合体的耐受小鼠中。同种异体 之所以选择BMT系统作为研究对象，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。这项研究 在此提出的建议应使我们能够获得必要的 将UVB-白细胞的耐受诱导转化为 临床实践。

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.