EXPRESSION AND FUNCTION OF PORCINE CLASS I MHC GENES IN TRANSGENIC MICE

猪I类主要组织相容性(MHC)基因已被引入 进入C57BL/10小鼠基因组中，以研究它们的体内模式 并分析其产品的功能能力。一 含有经典I类MHC基因(Pd1)的转基因株系表达 B1OPD1转基因细胞表面皮肤移植的SLA抗原 被正常C57BL/10小鼠排斥，表明外源SLA抗原 是公认的功能性移植抗原PD1的表达 与在猪身上观察到的相似，表明它的表达是 受监管的。转Sigma/β-干扰素基因的体内治疗 增加PD1在许多组织中的表达。为了进一步描述 负责组织特异性表达的调控DNA序列元件 在I类基因中，产生了一系列PD1的5‘端缺失突变体。脱氧核糖核酸 含有缺失突变体的构建物连接到报告基因， 猫，被引入转基因动物并对其进行了评估 表达方式。转录上游1.1 kb以内 确定了启动、消极和积极的调节要素，一些 它们以组织特有的方式发挥作用。特别是，一个复杂的 元素包含重叠的增强器和消音器演示 明显的组织特异性。 已经产生了含有猪I类基因PD7的转基因株系， 它与PD1密切相关。这两条线的不同之处在于 PD7中引入的非编码5‘侧翼序列 吉恩。对PD7在这两个细胞系中的表达分析揭示了这种情况的存在 与该基因相关的组织特异性沉默基因。不同之处在于 两个构造体中5‘侧翼序列的范围不仅导致 抗原表达水平不同，但移植物比率不同 拒绝。

Porcine class I major histocompatibility (MHC) genes have been introduced into the genome of C57BL/10 mice in order to study their in vivo patterns of expression and to analyze the ability of their products to function. One transgenic line which contains a classical class I MHC gene (PD1) expresses SLA antigen on its cell surface skin grafts from the B1O.PD1 transgenic are rejected by normal C57BL/10 mice, indicating that the foreign SLA antigen is recognized as a functional transplantation antigen Expression of PD1 parallels that observed in the swine, indicating that its expression is regulated. In vivo treatment of the transgenic with sigma/beta-interferon increases PD1 expression in a number of tissues. To further characterize regulatory DNA sequence elements responsible for tissue specific expression of class I gene, a series of 5' deletion mutants of PD1 was generated. DNA constructs containing the deletions mutants ligated to a reporter gene, CAT, were introduced into transgenic animals and assessed for their patterns of expression. Within 1.1 kb upstream of transcriptional initiation, negative and positive regulatory elements were identified, some of which function in a tissue specific fashion. In particular, a complex element consisting of an overlapping enhancer and silencer demonstrates marked tissue specificity. Transgenic lines have been generated containing a swine class I gene PD7, which is closely related to PD1. The two lines differ in the extent of non-coding 5' flanking sequence which has been introduced with the PD7 gene. Analysis of PD7 expression in the two lines has revealed the presence of tissue specific silencer associated with the gene. The difference in extent of 5' flanking sequences in the two constructs results not only in differential levels of antigen expression but different rates of graft rejection.