Prevention of IDDM by Expression of a Modified I-Ag7

描述(由申请人提供) 在男性和NOD中对IDDM易感性最高的基因 老鼠是MHC II类等位基因。人和小鼠IDDM相关的MHC 第II类基因在密码子beta-56上包含两个独特的氨基酸多态 和贝塔-57。共表达I-Ag7Abeta分子的转基因NOD小鼠 其中56位或57位突变不会发展成IDDM。这个 共表达抵抗IDDM的MHC II转基因所产生的保护作用 似乎涉及到骨髓来源的调节反应的诱导 细胞(BMDC)。 我们将检验以下假设：1)基因治疗定向表达 突变的I-Ag7Abeta基因可以阻止肿瘤的启动和进展， NOD小鼠自身免疫性疾病的发生；2)保护机制包括 监管反应的诱导。我们将专注于基因工程 BMDC和APC体外表达56和/或57位氨基酸取代的I-Ag7Abeta基因。通过在体外对骨髓间充质干细胞进行基因工程 我们应该能够获得高水平的突变I-Ag7Abeta表达和 避免在配子中引入任何基因改变的可能性。基于一个 一些考虑事项，我们首先将重点放在使用嵌合RNA/DNA上 引导I-Ag7Abeta基因定点突变的寡核苷酸 BMDC和APC基因组DNA中存在β-56或β-57密码子。其他医疗模式 表达修饰的I-Ag7 Abeta基因将得到测试，如果这一策略 结果证明是无效的。 IDDM耐药MHC-II类基因的表达具有潜在的临床意义 用于应用，因为这种方法可能比其他治疗方法侵入性小 这会广泛干扰免疫系统的功能。此外，它也可能是 适用于其他自身免疫性疾病，如多发性硬化症和 类风湿性关节炎，也与特定的MHC II类有关 等位基因。

DESCRIPTION (provided by applicant) The gene which confers the greatest susceptibility for IDDM in both man and NOD mice is the MHC class II allele. Both the human and murine IDDM-associated MHC class II genes contain two unique amino acid polymorphisms at codons beta-56 and beta-57. Transgenic NOD mice which co-express an I-Ag7 Abeta molecule in which either position 56 or 57 has been mutated do not develop IDDM. The protection conferred by co-expression of an IDDM-resistant MHC II transgene appears to involve the induction of regulatory responses by bone marrow derived cells (BMDC). We will test the hypotheses that: 1) the gene-therapy directed expression of a mutant I-Ag7 Abeta gene can prevent the initiation, as well as the progression, of autoimmune disease in NOD mice and; 2) the mechanism of protection involves the induction of regulatory responses. We will focus on genetically engineering BMDC and APC in vitro to express an I-Ag7 Abeta gene with substituted amino acids at positions 56 and/or 57. By genetically engineering the BMDC in vitro we should be able to achieve high levels of mutant I-Ag7 Abeta expression and avoid any possibility of introducing genetic alterations in gametes. Based on a number of considerations, we will initially focus on using chimeric RNA/DNA oligonucleotides to direct the site-specific mutagenesis of the I-Ag7 Abeta beta-56 or beta-57 codons in the genomic DNA of BMDC and APC. Other modalities of expressing a modified I-Ag7 Abeta gene will be tested if this strategy proves to be ineffective. The expression of an IDDM-resistant MHC class II gene has potential clinical for application, as this approach may be less invasive than other treatments that broadly interfere with immune system function. Furthermore, it may also be applicable to other autoimmune diseases such as multiple sclerosis and rheumatoid arthritis, which are also associated with specific MHC class II alleles.