HIGMX 1--TRANSGENIC MODELS OF CD40L DEFICIENCY

原发免疫缺陷疾病提供了独特的研究机会 离散细胞和分子在免疫反应中的作用。我们的 总体目标是了解CD40及其配体在免疫中的作用 通过对病人和转基因小鼠的研究来发挥作用 CD40L和CD40缺乏。 CD40在B细胞、胸腺上皮和树突状细胞上表达， 在B细胞的存活、激活、分化中起重要作用 和班级转换。表达了CD40的配体CD40L/gp39 以发育调节的方式独占激活的T细胞。 我们最近发现CD40L基因的突变会导致丢失 CD40L的功能或表达是X连锁的基础 高IgM综合征(HIGMX-1)。CD40缺乏症尚未出现 描述。 在目标1中，我们建议详细分析CD40L的机制 HIGMX-1基因缺失。我们将描述CD40L基因的缺陷 在一组HIGMX-1患者的基因水平和基因组水平上 水平。后者需要分析基因组组织和 人类CD40L基因的最小转录单位。 在目的2中，我们建议建立HIGMX-1小鼠模型，以获得 更好地了解CD40L缺陷并开始测试新的 HIGMX-1的治疗方式。为此，我们将产生 CD40L缺陷小鼠通过RAG-2缺陷的囊胚互补和 通过破坏CD40L生殖系基因。我们还将构建 CD40L离散突变的转基因小鼠模拟突变 在HIGMX-1患者中表达，并确定CD40L区域的功能。 在目标3中，我们将研究CD40在免疫发展中的作用。 细胞，并通过对CD40缺乏的研究确定CD40缺乏的表型 CD$0基因敲除小鼠。CD40在B细胞发育和功能中的作用 将通过检查由RAG-2构建的CD40缺陷小鼠来定义 胚泡补充不足。CD40在人类免疫缺陷中的作用 胸腺上皮细胞和树突状细胞的发育和功能 将在CD40L生殖系基因中断的小鼠身上进行分析。

Primary immunodeficiency diseases provide unique opportunities to study the role of discrete cells and molecules in the immune response. Our general aim is to understand the role of CD40 and of its ligand in immune function through the study of patients and of genetically engineered mice with CD40l and CD40 deficiency. CD40 is expressed on B cells, thymic epithelium and dendritic cells and plays an important role in B cell survival, activation, differentiation and class switching. The ligand for CD40 (CD40L/gp39) is expressed exclusively on activated T cells in a developmentally regulated manner. We have recently found that mutations in the CD40L gene resulting in loss of function or expression of CD40L are the basis for the X-linked HyperIgM syndrome(HIGMX-1). Deficiency in CD40 has not yet been described. In Aim 1, we propose to analyze in detail the mechanisms of CD40L deficiency in HIGMX-1. We will characterize the defect in the CD40L gene in a panel of HIGMX-1 patients at the cDNA level and at the genomic level. The latter requires an analysis of the genomic organization and of the minimal transcriptional unit of the human CD40L gene. In Aim 2, we propose to construct a murine model of HIGMX-1 to gain a better understanding of CD40L deficiency and to begin testing novel therapeutic modalities for HIGMX-1. To this purpose, we will generate CD40L deficient mice by RAG-2-deficient blastocyst complementation and by disruption of the CD40L germline gene. We will also construct transgenic mice with discrete mutations in CD40L to mimic the mutations in HIGMX-1 patients and to define the function of CD40L domains. In Aim 3, we will examine the role of CD40 in the development of immune cells and define the phenotype of CD40 deficiency through the study of CD$0 knockout mice. The role of CD40 in B cell development and function will be defined by examining CD40 deficient mice constructed by RAG-2 deficient blastocyst complementation. The role of CD40 in the development and function of thymic epithelial cells and dendritic cells will be analyzed in mice with disrupted CD40L germline gene.