BIOCHEMICAL RELATIONSHIP OF PLATELET AND PLASMA HLA

HLA是决定人类免疫功能的最重要的抗原系统。 同种免疫患者输注血小板的存活率。 为这些患者找到相容的血小板是一个主要障碍 血小板输注疗法 这项工作的主要目的是 建议是制定新的方法来克服 随机献血者免疫排斥反应 血小板 对于一种方法，我们将建立一个精确的 定量测定以测量每种特定的 血小板上的HLA。 一开始，单克隆抗体（MoAb） 针对HLA分子的单态性表位将被开发用于 通过用合成肽免疫小鼠， 含有保守的氨基酸序列。 的精确 血小板上每种特异性HLA的定量将通过 用已建立的酶测量血小板上的总HLA- 连接的免疫测定法，并通过测定每种 使用IEF-PAGE、抗HLA单克隆抗体和 免疫印迹。 然后可以使用结果来计算精确的 每种特定HLA的浓度。 这项试验将使我们能够 研究使用同种异体免疫患者进行免疫接种的潜在益处 与来自捐献者的血小板相比， 不匹配的HLA抗原 它也可以用来比较 血小板之间特异性HLA的可变表达， 淋巴细胞，研究定量的遗传调节 每种特定HLA在细胞上的表达，并研究 特异性HLA的可变表达与疾病的关联 易感性和免疫反应性。 另一方面，我们会展开实验研究， 用8-甲氧基补骨脂素和UV-A预处理的血小板的用途 辐射到受辐射污染的白细胞， 预防针对I类MHC的原发性同种异体致敏 小鼠体内的抗原 选择小鼠是因为它们的良好表征的H- 2系统和自交系的可用性， H-2单倍型。 这项研究的结果不仅将 为我们未来的临床试验提供重要信息 还将建立一个实验系统， 研究MHC体液免疫应答的机制， 抗原由供体白细胞触发。 在这方面的进一步研究 方向将有助于更好地了解 组织和器官移植免疫生物学

HLA is the most important antigenic system in determining the survival of transfused platelets in alloimmunized patients. Finding compatible platelets for those patients is a major obstacle in platelet transfusion therapy. The primary objective of this proposal is to develop new approaches for overcoming the immunological refractoriness to transfusion of random donor platelets. For one approach, we will establish a precise quantitative assay to measure the concentration of each specific HLA on platelets. At the beginning, monoclonal antibodies (MoAb) against monomorphic epitopes of HLA molecules will be developed for this assay by immunizing mice with synthetic peptides containing conserved amino-acid sequences. The precise quantitation of each specific HLA on platelets will be achieved by measuring the total HLA on a platelet with an established enzyme- linked immunoassay and by determining the relative quantity of each specific HLA on platelets using IEF-PAGE, anti-HLA MoAbs and immunoblots. The results can then be used to calculate the exact concentration of each specific HLA. This assay will enable us to study the potential benefit of transfusing alloimmunized patients with platelets from donors who have a low expression of one or two mismatched HLA antigens. It can also be used to compare the variable expression of specific HLA between platelets and lymphocytes, to study the genetic regulation of quantitative expression of each specific HLA on cells, and to investigate the linkage of variable expression of specific HLA to disease susceptibility and immune responsiveness. For another approach, we will initiate experimental studies on the use of platelets pretreated with 8-methoxypsoralen and UV-A irradiation to inactivate contaminating leukocytes for the prevention of primary allosensitization against class I MHC antigens in mice. Mice are chosen for their well characterized H- 2 system and the availability of inbred strains with well defined H-2 haplotypes. The results of this proposed study not only will provide us with important information for a future clinical trial but also will establish an experimental system that can be used to study the mechanisms by which the humoral immune response to MHC antigen is triggered by donor leukocytes. Further research in this direction will contribute to a greater understanding of the immunobiology of tissue and organ transplantation.