Generation and characterization of an antibody-based mouse model for systemic sclerosis

在前一阶段，我们已经建立了一种新的小鼠模型，该模型由抗人血管紧张素受体1型(AT1R)的自身免疫诱导而成，类似于系统性硬化症(SSC)的几个特征，例如纤维化、血管病变和自身免疫。这些小鼠的临床表型与平行分析的人类内皮素受体A型(ETAR)免疫诱导的小鼠的表型非常相似。过继转移脾细胞可将疾病转移到C56/BL6小鼠体内。HAT1R免疫小鼠的抗体(Ab)具有诱导IL-8和增加大鼠心肌细胞自发性搏动频率的能力。在应用阶段，我们的目标是进一步鉴定hAT1R免疫的小鼠模型。我们想要确定疾病过程的动态和受体表达对免疫细胞功能、免疫细胞稳态和局部浸润组织的作用。抗AT1R抗体将通过研究其特异性、识别的表位、糖基化、亲和力以及与抗ETAR抗体的差异来进行表型和功能表征。我们的目的是在体外研究抗AT1R抗体对细胞因子诱导、细胞信号转导和mRNA转录的影响，特别是对SSC中的关键细胞因子IL-6和转化生长因子B的产生的影响。在体内，我们将确定抗体诱导SSC特征的效果。为了证明ab诱导AT1R激活的因果作用，我们将使用AT1R缺陷小鼠，并将使用来自AT1R免疫小鼠以及来自单功能抗AT1R抗体的Ig G的Fab片段。对FcɣR缺陷小鼠的AT1R免疫将阐明恒定ab区在诱导病理过程中的作用。通过过继转移实验，我们将进一步鉴定导致或促成疾病表型的免疫细胞。我们希望找到新的致病机制和治疗靶点。

In the previous period, we have generated a novel mouse model induced by autoimmunity against the human angiotensin receptor type-1 (AT1R) resembling several features of systemic sclerosis (SSc), e.g. fibrosis, vasculopathy, and autoimmunity. The clinical phenotype of these mice is very similar to the phenotype of mice induced by immunization against the human endothelin receptor type-A (ETAR) analyzed in parallel. Disease can be transferred into C56/Bl6 mice by adoptive transfer of splenocytes. Functional activity of antibodies (ab) from hAT1R-immunized mice was shown by their ability to induce IL-8 and to increase the spontaneous beating rate in rat cardiomyocytes. In the applied period, we aim to further characterize the hAT1R-immunized mouse model. We want to identify the dynamic of the disease process and the role of receptor expression on immune cell function, for immune cell homeostasis, and on tissues for local Infiltration. Anti-AT1R ab will be phenotypically and functionally characterized by studying their specificity, their recognized epitopes, their glycosylation, their affinity, and their differences to anti-ETAR ab. We aim to study in vitro the effects of the anti-AT1R ab on cytokine induction, cell signaling, and mRNA transcription particularly for the generation of IL-6 and TGFß, which are key cytokines in SSc. In vivo, we will identify the effects of the antibodies to induce SSc features. To proof the causal role ab-induced AT1R activation, we will apply AT1R-deficient mice and will use Fab fragments of IgG from AT1R-immunized mice as well as from monoclonal functional anti-AT1R antibodies. AT1R immunization of FcɣR-deficient mice will clarify the role of the constant ab region to induce pathologies. By using adoptive transfer experiments, we will further identify immune cells causing or contributing to the disease phenotype. We hope to identify novel disease mechanisms and therapeutic targets.