Therapeutic use of inhibitory DNA sequences in animal models of lupus

描述(申请人提供)：系统性红斑狼疮(SLE)是一种慢性自身免疫性疾病，经常导致广泛的炎症和严重的器官损害。最近的研究表明，Toll样受体，尤其是TLR9参与了SLE的发病机制。TLR9配体，如细菌DNA和合成的CpG寡核苷酸(ODN)，可以激活人类的树突状细胞和B细胞。然而，与记忆B细胞和边缘带(MZ)B细胞相比，人类的幼稚B细胞和小鼠的滤泡B细胞对复杂的CpG-DNA配体的刺激反应非常差。作为TLR9刺激的结果，B细胞增殖，上调共刺激分子，并分泌抗体和细胞因子，如IL-6和IL-10。有人担心，通过TLR9的刺激可能会导致未成熟的自身反应性B细胞存活，从而直接涉及TLR9在系统性自身免疫的发病机制中的作用。虽然哺乳动物的DNA总体上是非免疫刺激的，但在某些条件下，狼疮患者循环免疫复合体中的DNA可以刺激自身反应性B细胞和树突状细胞。因此，在狼疮的早期阶段选择性阻断TLR9通路可能是治疗狼疮的一种有前途的工具。在过去的几年里，我们已经开发了一系列短的ODN，它们选择性地阻断通过TLR9的免疫激活，但不通过其他信号通路激活B细胞。最近的结构修改导致了这类新的小DNA抑制剂(R类)，它们对不同表达TLR9的细胞显示出不同的选择性。这位研究人员希望，未来在治疗人类狼疮时使用这些药物可能会提供更多针对疾病的治疗方法，避免不必要的免疫抑制。 在这笔赠款的目标1中，我们研究了毛囊细胞和MZ-B细胞对复杂的CpG-DNA配体的不同反应能力。我们研究了CpG-DNA被淋巴细胞摄取的机制、DNA的运输以及PI-3K家族的作用。我们讨论了干扰素启动在B细胞激活中的作用。在目标2中，我们研究了新近发展起来的R-INH-ODN的结构要求和作用机制。在目标3中，我们研究了这些INH-ODN是否能够预防或延缓动物狼疮的发生，或者降低临床狼疮小鼠的发病率。未来将这些研究扩展到人类，可能会导致设计出治疗人类系统性红斑狼疮的新型治疗剂。

DESCRIPTION (provided by applicant): Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that frequently causes widespread inflammation and serious organ damage. Recent studies have implicated toll-like receptors, particularly TLR9 in the pathogenesis of SLE. TLR9 ligands, such as bacterial DNA and synthetic CpG-oligonucleotides (ODN), activate dendritic cells and B cells in humans. However, naive B cells in humans, and follicular B cells in mice, in contrast to memory B cells and marginal zone (MZ) B cells, respond very poorly to stimulation with complex CpG-DNA ligands. As a result of TLR9 stimulation, B cells proliferate, upregulate co-stimulatory molecules and secrete antibodies and cytokines, e.g., IL-6 and IL-10. There is a concern that stimulation via TLR9 may cause a survival of immature autoreactive B cells, thus directly implicating TLR9 in the pathogenesis of systemic autoimmunity. Although mammalian DNA in general is non-immune stimulatory, under some conditions, DNA found in circulating immune complexes in lupus patients could stimulate autoreactive B cells and dendritic cells. Therefore, selectively blocking TLR9 pathway during early stages of lupus may be a promising tool for treating lupus. Over the last few years, we have developed a series of short ODNs that selectively block immune activation via the TLR9, but spare B cell activation via other signaling pathways. Recent structural modifications have resulted in the new class of these small DNA inhibitors (Class R) that show differential selectivity for various TLR9 expressing cells. The investigator hopes that the future use of these drugs in the treatment of human lupus may provide more disease-specific cure, avoiding unnecessary immunosuppression. In the Aim 1 of this grant, we investigate differing abilities of follicular and MZ-B cells to respond to complex CpG-DNA ligands. We study mechanisms responsible for CpG-DNA uptake into lymphoid cells, DNA trafficking and the role of the PI-3K family. We address the role of interferon priming in B cell activation. In Aim 2, we study the structural requirements and mechanism of action of recently developed class R-INH-ODNs. In Aim 3, we investigate whether these INH-ODNs can prevent or delay the onset of animal lupus, or decrease morbidity in mice with clinical lupus. Future extension of these studies to humans may lead to the design of novel therapeutic agents for human SLE.