Cytokine mechanisms in systemic lupus erythematosus

描述(申请人提供)：系统性红斑狼疮(SLE)是一种普遍存在的人类系统性自身免疫性疾病，其发病机制尚不清楚。因此，旨在了解疾病机制的努力具有高度相关性。因为研究人类系统性红斑狼疮是困难的，由于多种原因，我们开发了新的易患狼疮的NZBxNZW衍生的同源NZM系，这些NZM系要么缺乏Stat-4，要么缺乏Stat-6。Stat缺陷小鼠提供了独特的工具，以更好地了解AutoAbs和细胞因子在疾病发病机制中所起的作用，并可能有助于剖析SLE中介导肾损害的机制。在大量初步数据的支持下，我们建议解决以下问题：(1)STAT4缺陷狼疮小鼠的肾脏疾病是依赖还是独立于自身抗体？为此，我们培育了B细胞缺陷的NZM2328突变小鼠，我们将在没有循环、可溶性自身抗体的情况下恢复B细胞，然后将这些小鼠与STAT4 KO杂交。(2)干扰素-γ对星型缺陷NZM小鼠自身抗体的产生和靶器官疾病的发生是否必要？这一特定的目的将检验这样的假设，即缺乏IFNGamma可能会通过STAT4-/-小鼠的调节机制失败而导致疾病的早期启动。为了实现这一目标，我们将使用两种不同的方法直接和系统地测试IFNGamma在Stat缺乏的NZM小鼠狼疮样疾病发展的不同阶段中的作用：a)在体内使用IFNGamma和抗IFNGamma试剂进行限定时间的治疗方案，以及b)一种遗传方法，其中将以组织和时间特定的方式开发IFNGamma的条件表达系统。(3)我们能否在免疫缺陷的NZM小鼠中重建Stat缺陷表型？为了实现这一点，我们将通过在IL-7Rα和c-kit受体中引入功能突变来产生完全免疫缺陷的NZM2328，从而允许与任何供体菌株进行造血重建，而不需要进行移植前的调节。(4)两种STAT4亚型对NZM2328狼疮小鼠的免疫系统和靶器官有何直接影响？为此，我们将STAT4基因缺陷的NZM2328小鼠与STAT4-α和STAT4-β转基因小鼠杂交，恢复T淋巴细胞中的STAT4，并利用微阵列技术研究这些狼疮小鼠淋巴细胞和肾小球中的差异表达基因。这些研究应该有助于更好地了解SLE的一些特征，并可能导致确定新的治疗靶点。

DESCRIPTION (provided by applicant): The pathogenesis of systemic lupus erythematosus (SLE), a prevalent human systemic autoimmune disease, is still unknown. Thus, efforts aimed at understanding disease mechanisms are highly relevant. Because studying humans with SLE is difficult for multiple reasons, we have developed novel genetically lupus-prone NZBxNZW derived congenic NZM lines that are either Stat-4 or Stat-6 deficient. The Stat deficient mice offer unique tools to achieve a better understanding of the role that autoAbs, and cytokines play in the pathogenesis of the disease and may allow dissection of the mechanisms that mediate renal damage in SLE. Backed up by substantial preliminary data, we propose to address the following questions: (1) Is the kidney disease in Stat4 deficient lupus mice dependent or independent of autoAbs? To this end we have produced B-cell deficient NZM2328 mutant mice into which we will restore B cells in the absence of circulating, soluble autoAbs and then cross these mice with Stat4 KO. (2) Is IFN-gamma necessary for the development of autoAbs and target organ disease in Star-deficient NZM mice? This specific aim will test the hypothesis that the absence of IFNgamma may result in early initiation of disease through a failure of regulatory mechanisms in the Stat4-/- mice. To accomplish this we will test directly and systematically the role of IFNgamma at different stages of lupus-like disease development in Stat deficient NZM mice using two different approaches: a) in vivo treatment protocols using IFNgamma and anti-IFNgamma reagents for defined periods of time, and b) a genetic approach in which a conditional expression system for IFNgamma in a tissue-and time-specific manner will be developed. (3) Can we reconstitute the Stat deficient phenotypes in immunodeficient NZM mice? To accomplish this, we will generate NZM2328 completely immunodeficient by introducing a loss of function mutation in both the IL-7R alpha and c-kit receptors that allows hematopoietic reconstitution with any donor strain without requiring administration of pre-transplant conditioning. (4) What are the direct effects of the two Stat4 isoforms on the immune system and on the target organ in NZM2328 lupus mice? For this purpose we will restore Stat4 in T lymphocytes of Stat4 deficient NZM2328 mice by crossing them with Stat4- alpha and Stat4-beta transgenic mice and will study differentially expressed genes in lymphocytes and glomeruli of these lupus mice using micro-array technology. These studies should lead to better understanding of a number of characteristics of SLE and may lead to identification of new targets for therapy.