Do estrogen receptors in B cells and DC mediate sex bias in murine lupus?

描述(申请人提供)：系统性红斑狼疮(SLE)是一种自身免疫性疾病，优先影响育龄女性(9：1)，表明包括性激素雌二醇在内的性别特异性因素在狼疮发病中起重要作用。狼疮的小鼠模型在雌性小鼠中表现出疾病的自然早期表现和随后的死亡。在NZM2410小鼠中存在的Sle1和Sle3狼疮易感基因座直接增加了雌性狼疮的疾病外显率，这与研究表明全身雌二醇的升高或暴露于雌激素环境化合物会加速狼疮的发展是一致的。要了解SLE以女性为主的发病机制，我们需要准确地确定内源性雌激素和雌激素受体(ER)如何调节B淋巴细胞和树突状细胞(DC)等免疫细胞的功能，这些细胞表达ER并参与狼疮的发病。然而，目前研究雌激素对免疫细胞影响的模型往往涉及全身暴露于超生理水平的雌二醇或全球雌激素受体丢失，这会造成激素失衡。全身雌激素水平的升高导致造血祖细胞的严重枯竭，导致B细胞和DC的数量和表型发生变化。为了避免ER配体对免疫细胞发育的这些影响，我们建议开发和使用一种新的小鼠狼疮模型，在该模型中，ERAlpha的表达可能在分化的B细胞或DC中特异性地被消融。我们将使用慢病毒转基因将CD19或CD11c启动子驱动的Cre重组酶转移到狼疮易感B6。这一方法将使我们能够确定与性敏感基因Sle1和Sle3相关的异常DC或骨髓后B细胞表型是否是由内源性雌激素对B细胞或DC的直接影响所介导的。在目标1中，我们将确定是否DC数量增加或DC表型过度激活导致雌性B6小鼠产生促炎细胞因子。Sle13双基因小鼠是内源性雌激素直接作用于DC的结果。在目标2中，我们将确定雌性B6Sle13双基因小鼠过渡性B细胞亚群的扰动和随后增强的血清学耐受性丧失是否是内源性雌激素对承诺的B细胞和/或DC直接作用的结果。这一慢病毒转基因策略的成功实施将建立一个通用的模型，可以用来研究任何细胞类型的ERpha信号在狼疮性肾炎发展过程中的作用。人类和小鼠免疫系统的公共卫生相关细胞能够对雌激素、植物雌激素以及用于治疗乳腺癌和骨质疏松症的药物做出反应。我们试图了解雌激素如何在自身免疫性疾病系统性红斑狼疮中控制免疫系统的关键调节细胞，称为树突状细胞和B细胞的发育和功能。这一知识将有助于理解为什么自身免疫性疾病优先困扰女性。

DESCRIPTION (provided by applicant): Systemic lupus erythematosus (SLE) is an autoimmune disease that preferentially affects women (9:1) in their reproductive years, indicating that sex specific factors including the sex hormone estradiol play an important role in lupus pathogenesis. Murine models of lupus show natural earlier expression of disease and ensuing mortality in female mice. The Sle1 and Sle3 lupus susceptibility loci present in NZM2410 mice direct increased penetrance of disease in females, which is consistent with studies showing that elevation of systemic estradiol or exposure to estrogenic environmental compounds accelerate lupus development. An understanding of the mechanisms underlying the female preponderance of SLE requires that we precisely determine how endogenous estrogens and estrogen receptors (ER) regulate the function of immune cells such as B lymphocytes and dendritic cells (DC), which express ER and have been implicated in lupus pathogenesis. However, current models for the study of estrogen effects on immune cells often have involved systemic exposure to supra-physiological levels of estradiol or global loss of ER, which creates hormonal imbalances. Elevated systemic levels of estradiol result in a profound depletion of hematopoietic progenitors, leading to alterations in numbers and phenotype of B cells and DC. To circumvent these effects of ER ligands on immune cell development, we propose to develop and use a novel model of murine lupus in which ERalpha expression may be specifically ablated in differentiated B cells or DC. We will use lentiviral transgenesis to deliver Cre recombinase driven by the CD19 or CD11c promoters to lupus prone B6.Sle13 bicongenic mice bearing a conditional ERalpha allele. This approach will allow us to determine whether aberrant DC or post-bone marrow B cell phenotypes associated with the sex sensitive Sle1 and Sle3 loci are mediated by direct effects of endogenous estrogens on B cells or DC. In Aim 1, we will determine if the elevated DC numbers or hyper-activated DC phenotypes leading to pro-inflammatory cytokine production in female B6.Sle13 bicongenic mice are a result of the direct action of endogenous estrogen on DC. In Aim 2, we will determine whether perturbations in transitional B cell subsets and subsequent enhanced loss of serologic tolerance in female B6.Sle13 bicongenic mice are a result of the direct action of endogenous estrogen on committed B cells and/or DC. The successful implementation of this lentiviral transgenesis strategy to delete ERalpha in specific cell types will establish a versatile model that could be used to study the role of ERalpha signaling in any cell type during the development of lupus nephritis. PUBLIC HEALTH RELEVANCE Cells of the human and murine immune systems are capable of responding to estrogens, phytoestrogens and drugs used for treatment of breast cancer and osteoporosis. We seek to understand how estrogens control the development and function of key regulatory cells of the immune system, termed dendritic cells and B cells, during the autoimmune disease Systemic Lupus Erythematosus. This knowledge will help to understand why autoimmune diseases preferentially afflict women.