ANTIGEN PRESENTING CELLS OF THE SKIN

皮肤抗原呈递细胞

• 批准号: 3457437
• 负责人: BRUCE Jack LONGLEY
• 金额: $ 11.48万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-01 至 1996-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3457437
• 关键词: CD antigens; Langerhans' cell; T cell receptor; T lymphocyte; antigen presentation; antigen presenting cell; cell cell interaction; cell mediated lymphocytolysis test; chromium; clone cells; genetic manipulation; genetically modified animals; human tissue; laboratory mouse; leukocyte activation /transformation; nucleic acid sequence; polymerase chain reaction; radionuclides; radiotracer; site directed mutagenesis; skin; transfection; virus antigen; virus protein

This project will investigate cutaneous antigen presenting cells by determining the function of CD1a, a non-polymorphic molecule expressed by Langerhans cells (LC). Similarities between CD1a and class I major histocompatibility (MHC) molecules suggest that CD1a can bind peptide antigen. Like class I MHC molecules, mediates cytotoxicity via the T-cell receptor (TCR) for antigen, but the role of added antigen in this interaction has not been determined. The first specific aim uses two strategies to determine whether CD1a specific T-cells recognize antigen bound to CD1a or recognize only distinct portions of CD1a. First, amino acids in the floor of the putative antigen binding groove formed by CD1a will be changed by site directed mutagenesis in order to displace any peptide normally bound int he groove. If changes of one or two amino acids alter the recognition of CD1a by multiple T-cell clones, then the hypothesis that TCRs interact with peptide antigen bound to CD1a will be supported since these amino acids should not be accessible for direct contact with the TCR. Next, T-cells from sensitized donors will be screened for recognition of specific antigens presented by cells expressing transfected CD1a but lacing classical MHC molecules. T-cells reacting only in the presence of both CD1a and antigen must be recognizing the antigen presented by CD1a. For the second specific aim, an estimate of the number of antigens which could be presented by CD1a will be made by amplifying and sequencing TCR mRNA sequences from CD1a specific T-cells. The third specific aim will test the ability of CD1a to present specific antigens in vivo by developing transgenic mice that express human CD1a controlled by murine class I MHC gene regulatory sequences. Since transgenic mice can be induced to express functional human class I MHC molecules, it is anticipated that transgenic human CD1a will also be functional. The mice will be immunized and tested for the ability to use CD1a as an antigen presenting molecule. Because presentation of specific antigens by non- polymorphic human molecules has not been previously demonstrated, these studies will provide new information about TCR recognition of antigens and about special properties of epidermal LC.

该项目将通过以下方式研究皮肤抗原呈递细胞 确定 CD1a 的功能，CD1a 是一种非多态性分子，由 朗格汉斯细胞（LC）。 CD1a 和 I 类专业之间的相似之处 组织相容性 (MHC) 分子表明 CD1a 可以结合肽 抗原。 与 I 类 MHC 分子一样，通过 T 细胞介导细胞毒性 抗原受体（TCR），但添加抗原在此过程中的作用 相互作用尚未确定。 第一个具体目标使用两个 确定 CD1a 特异性 T 细胞是否识别抗原的策略 结合 CD1a 或仅识别 CD1a 的不同部分。 一、氨基 CD1a 形成的推定抗原结合沟底部的酸 将通过定点诱变进行改变，以取代任何 肽通常结合在凹槽中。 如果一两个氨基酸发生变化 改变多个 T 细胞克隆对 CD1a 的识别，然后 TCR 与结合 CD1a 的肽抗原相互作用的假设 支持，因为这些氨基酸不应该直接用于 与 TCR 接触。 接下来，来自致敏捐赠者的 T 细胞将被 筛选识别表达细胞呈递的特定抗原 转染CD1a但带有经典MHC分子。 仅T细胞发生反应 在 CD1a 和抗原同时存在的情况下必须识别抗原 由 CD1a 提出。 对于第二个具体目标，估计数量 CD1a 可以呈递的抗原将通过扩增和 对 CD1a 特异性 T 细胞的 TCR mRNA 序列进行测序。 第三个 具体目的将测试CD1a在细胞中呈递特定抗原的能力 通过开发表达人 CD1a 的转基因小鼠体内 鼠I类MHC基因调控序列。 由于转基因小鼠可以 诱导表达功能性人类 I 类 MHC 分子， 预计转基因人类 CD1a 也将具有功能。 老鼠们 将进行免疫并测试使用 CD1a 作为抗原的能力 呈现分子。 因为非特异性抗原呈递 人类分子的多态性此前尚未被证实，这些 研究将提供有关 TCR 识别抗原的新信息 关于表皮 LC 的特殊性质。