STUDIES OF TRYPANOSOMAL EXOANTIGENS

在医学和经济上具有重要意义的非洲锥虫，例如 布氏锥虫可引起保护性、杀锥性反应， 由于抗原性的变化，只是暂时有效。类似 对非致病性啮齿动物之一的莱维氏锥虫也有反应。 锥虫，但这种寄生虫的良性本质实际上是由 一种由宿主产生的独特的繁殖抑制(非繁殖)免疫反应。 此外，激发抗原存在于寄生虫的表面。 在血液中作为循环中的外源抗原。 诱导对勒维氏锥虫产生强烈反应的抗原(阿司他林) 现已被孤立，并在非洲寻找对应的 锥虫现在是可行的。因此，以下是研究 建议：1.)已从锥虫提取物中分离出成纤维细胞原 在用发泡抗体制成的免疫吸附柱上，也将类似 从表面涂层材料、膜和血液中分离出； 所有这些来源的抗原都将以标准 生化技术，比较和进一步纯化，以确定 响应所需的最小数量。2.)免疫复合体已经被 从血液中分离出来的，显示含有造血素原。类似的研究 将确定莱维氏锥虫的变异抗原是否也 以免疫复合体的形式出现。3.)这两种抗原的变异抗原 莱维氏锥虫的变种将在免疫吸附树脂柱上分离， 对其进行了表征，并与其进行了比较。4.)单克隆抗体 将被送往T.lewiti。这些抗体将用于 免疫吸附柱用来分离成纤维蛋白原和变异体抗原， 用于刺激活动的功能研究，并确定更纯净的 可以获得具有生物活性的抗原。5.)一种文化体系， 允许不断生长的血液形式的莱维氏锥虫被发现 并将被进一步开发用于Ablasta的长期研究 并研究外源抗原的释放和免疫复合体的形成。6.) 布鲁氏毛滴虫抗原变异体的细胞表面将被分析 共享的、可访问的、不变的抗原 免疫原性，因为有证据表明存在这样的抗原。其中包括 可能是促分化蛋白原的对应物，可用于规避 抗原变异对实际免疫造成的障碍。

The medically and economically important African trypanosomes, such as Trypanosoma brucei, elicit protective, trypanocidal responses, which, because of antigenic variation, are only temporarily effective. Similar responses also occur against T. lewisi, one of the nonpathogenic rodent trypanosomes, but the benign nature of this parasite actually results from a unique reproduction-inhibiting (ablastic) immune response by the host. Furthermore, the eliciting antigens occur on the surface of the parasites and in the blood as circulating exoantigens. Antigens (ablastinogens) that elicit the ablastic response to T. lewisi have now been isolated, and a search for counterparts in the African trypanosomes is now feasible. Therefore, the following studies are proposed: 1.) Ablastinogens have been separated from trypanosome extracts on immunoadsorbent columns made with ablastic IgG and will be similarly isolated from surface coat material, pellicular membranes and blood; antigens from all these sources will be characterized by standard biochemical techniques, compared and further purified to determine the minimum number required for a response. 2.) Immune complexes have been isolated from the blood and shown to contain ablastinogen. Similar studies will be made to determine whether the variant antigens of T. lewisi also occur as immune complexes. 3.) The variant antigens of the two antigenic variants of T. lewisi will be isolated on immunoadsorbent columns, characterized and compared with ablastinogen. 4.) Monoclonal antibodies will be made to T. lewisi. These antibodies will be used in immunoadsorbent columns to isolate ablastinogen and the variant antigens, for functional studies of ablastic activity, and to determine whether purer biologically active antigens can be obtained. 5.) A culture system that allows continuous growth of bloodstream forms of T. lewisi has been found and will be developed further for use in long-term studies of ablastic effects, and to study exoantigen release and immune complex formation. 6.) The cell surface of antigenic variants of T. brucei will be analyzed for shared, accessible, non-variant antigens that are not ordinarily immunogenic, since there is evidence that such antigens occur. Among these may be counterparts of ablastinogen that could be used to circumvent the obstacles to practical immunization created by antigenic variation.