MURINE T LYMPHOCYTE SUBSETS AND ALLOGRAFT REJECTION

T细胞、B细胞和抗原提呈细胞之间的相互作用启动 由细胞因子和细胞介导和调节的免疫反应 表面相互作用。CD4T细胞亚群已在 分泌型淋巴因子的基础。CD8 T细胞亚群尚未被 详细地描述了。这项研究的总体目标是 项目2是描述调节的功能的机制 与同种异体移植排斥反应有关的T淋巴细胞 强调CD8 T细胞。我们将定义CD8 T细胞亚群 与单个主要组织相容性复合体(MHC)抗原反应为 以及确定控制这些T细胞反应的机制 细胞子集。我们将主要研究对I类MHC抗原的反应， 尤其是H-2LD。为实现这一目标，提出了三个具体目标 总目标：1)测定细胞因子和细胞表面分子 参与激活初始和预置的CD8T细胞的反应 用H-2LD类L MHC抗原，用来自其转基因小鼠的T细胞 CD8 T细胞表达抗原特异的转基因(TG)α/βT 与H-2LD同种异体抗原反应的细胞受体(TCR)。朴素CD8 T 细胞将从未经准备的脾和淋巴结中获得。敏化 CD8T细胞将从淋巴引流部位获得 排斥异体皮肤移植或经腹膜后的脾移植 注射同种异体细胞。特定淋巴因子的作用(包括 IL-1、IL-2、IL-4、IL-10和IL-12)和细胞表面分子(包括 B7-1、B7-2、CD28、CTLA-4、LFA-1、ICAM-1)促进增殖， 淋巴因子的产生，并获得细胞溶解活性 使用中和单抗(MAb)和各种 抗原提呈细胞群(APC)；2)获得克隆 代表各种CD8 T细胞亚群，并比较 用控制幼稚的克隆来调节这些克隆的各种功能 CD8T细胞。为实现具体目标1而提出的实验应 定义基本条件(淋巴因子和细胞表面分子) 刺激CD8TG T细胞产生淋巴因子 CD4T辅助(Th)细胞亚群，即白细胞介素性(IL) Th1和IL-4、IL-5、IL-6和IL-10的干扰素-γ 对于Th2。使用此信息，我们将定义导致 有选择地激活一个或另一个子集，我们将推导出 能分泌不同淋巴因子阵列的CD8TG T细胞克隆。我们 将确定代表CD8亚群的克隆的功能，测量 淋巴因子的产生、B细胞帮助的提供和细胞溶解活性 由穿孔素和Fas介导。我们还将评估各种不同的能力 CD8亚群对初始CD_4和CD_8 T细胞及CD_4应答的调节 和CD8体外克隆；以及3)基于通过 另一个具体目标是制定抑制同种异体移植的策略 拒绝。可能的治疗方法包括使用与 与细胞发生反应的特定细胞因子和/或单抗或其他试剂 特定T细胞亚群或APC的表面结构。

Interactions among T cells, B cells, and antigen-presenting cells initiate immune responses which are mediated and regulated by cytokines and by cell surface interactions. Subsets of CD4+ T cells have been identified on the basis of secreted lymphokines. Subsets of CD8+ T cells have not been characterized in detail. The general goal of the research proposed in Project 2 is to characterize the mechanisms that regulate the functions of T lymphocytes which are responsible for rejection of allografts, with emphasis placed on CD8+ T cells. We will define CD8+ T cell subsets reacting to individual major histocompatibility complex (MHC) antigens as well as determining the mechanisms that control the responses of these T cell subsets. We will study mainly the response to class I MHC antigens, particularly H-2Ld. Three Specific Aims are proposed to accomplish this general goal: 1) To determine the cytokines and cell surface molecules that are involved in activating naive and primed CD8+ T cells reactive with H-2Ld class l MHC antigen, using T cells from transgenic mice whose CD8+ T cells express an antigen-specific, transgenic (Tg), alpha/beta T cell receptor (TCR) which reacts with H-2Ld alloantigen. Naive CD8+ T cells will be obtained from unprimed spleen and lymph nodes. Sensitized CD8+ T cells will be obtained from lymph nodes draining the site of a rejecting skin allograft or from the spleen following intraperitoneal injection of allogeneic cells. The role of specific lymphokines (including IL-1, IL-2, lL-4, lL-1O and lL-12) and cell surface molecules (including B7-1, B7-2, CD28, CTLA-4, LFA-1, ICAM-1) in activation for proliferation, lymphokine production, and acquisition of cytolytic activity will be determined, using neutralizing monoclonal antibodies (mAb) and various populations of antigen-presenting cells (APC); 2) To derive clones representing various CD8+ T cell subsets and compare the mechanisms that regulate various functions of these clones with those controlling naive CD8+ T cells. The experiments proposed to accomplish Specific Aim 1 should define the essential conditions (lymphokines and cell surface molecules) for stimulating CD8+ Tg T cells to produce those lymphokines that have distinguished subsets of CD4+ T helper (Th) cells, namely interleukin (IL) 2 and interferon-gamma (IFN-gamma) for Th1 and IL-4, lL-5, lL-6, and lL-10 for Th2. Using this information, we will define conditions that lead selectively to activation of one or another subset, and we will derive clones of CD8+ Tg T cells that secrete different lymphokines arrays. We will determine functions of clones representing CD8+ subsets, measuring lymphokine production, provision of B cell help, and cytolytic activity mediated by perforin and Fas. We also will evaluate the ability of various CD8+ subsets to regulate responses of naive CD4+ and CD8+ T cells and CD4+ and CD8+ clones in vitro; and 3) Based on the information obtained through the other Specific Aims, to develop strategies for suppressing allograft rejection. Possible therapies include the use of mAb reactive with particular cytokines and/or mAb or other reagents that react with cell surface structures on the particular T cell subsets or APC.