Modulation of immunological processes by KSRP

免疫细胞功能活动的调节需要基因表达的动态快速适应。在永生化细胞系中，KSRP(KH型剪接调节蛋白)被报道限制了编码细胞因子的mRNAs的mRNA稳定性，并介导了microRNA-155的成熟，已知这有助于免疫细胞的调节。KSRP限制了I型干扰素编码基因的半衰期，KSRP-/-小鼠对病毒感染表现出更高的抵抗力。我们的初步工作表明，KSRP通过影响中性粒细胞(PMN)的迁移活性来影响其功能活性。此外，RNA-Seq和细胞因子检测证实，KSRP-/-CD4+T细胞对刺激的反应具有固有的辅助性T细胞2型(Th2)倾向。同样，KSRP-/-小鼠出现了较温和的胶原抗体诱导性关节炎(CAIA)，已知是由髓系细胞和Th1细胞引起的。同样，KSRP-/-小鼠在卵蛋白(OVA)诱导的哮喘中表现出加重的过程，我们的结果表明KSRP构成了一个未知的免疫反应的重要调节因子。我们的研究旨在描述KSRP在调节先天性和获得性免疫反应中的作用，作为设想KSRP重点治疗方法的先决条件。我们想要证实我们关于OVA相关性哮喘加重过程的初步发现，并详细阐明T细胞、B细胞和PMN的相对贡献。我们将在分子水平上剖析KSRP抑制CD4+T细胞Th2促进IL-4表达的机制，包括重要的转录因子和信号转接子的鉴定。在此背景下，我们还将根据我们的RNA-Seq结果区分T细胞中直接和间接的KSRP靶基因。我们将剖析KSRP缺乏对B细胞免疫表型和功能的内源性和外源性(Th2帮助)影响，涉及体液免疫反应的特征。此外，还将研究KSRP缺陷的CD4+T细胞增殖增强的原因以及KSRP介导的调节性T细胞功能。KSRP与PMN病原体杀灭活性的功能相关性将在曲霉病模型中进行监测。此外，我们将在哮喘模型中进行救援实验，以证实KSRP用于免疫药理干预的适宜性。将产生具有细胞类型特异性KSRP基因敲除的小鼠，以确认哮喘研究中的关键实验。

The regulation of the functional activities of immune cells requires dynamic rapid adaption of gene expression. In immortalized cell lines, KSRP (KH-type splicing regulatory protein) was reported to limit mRNA stability of cytokine-encoding mRNAs and to mediate microRNA-155 maturation, known to contribute to immune cell regulation. KSRP limited the half-life of type I interferon-encoding genes, and in agreement KSRP-/- mice displayed higher resistance towards viral infection. Our preliminary work indicated that KSRP affects the functional activity of polymorphonuclear neutrophilic granulocytes (PMN) in terms of migratory activity. Moreover, KSRP-/- CD4+ T cells were characterized by an intrinsic T helper cell type 2 (Th2) bias in response to stimulation as confirmed by RNA-Seq and cytokine measurements. In line, KSRP-/- mice presented a milder course of collagen antibody induced-arthritis (CAIA) known to be caused by myeloid and Th1 cells. Similarly, KSRP-/- mice presented an aggravated course in ovalbumin (OVA)-induced asthma Taken together, our results indicate that KSRP constitutes a yet unknown important regulator of immune responses.Our study is aimed to delineate the role of KSRP for the regulation of innate and adaptive immune responses as a prerequisite to envisage KSRP-focused therapeutic approaches. We want to substantiate our preliminary findings concerning the aggravated course of OVA-associated asthma, and elucidate in detail the relative contribution of T cells, B cells and PMN. We will dissect on molecular level by which mechanisms KSRP inhibits expression of Th2-promoting IL-4 in CD4+ T cells, including the identification of important transcription factors and signalling adaptors. In this context, we will also discriminate direct and indirect KSRP target genes in T cells based on our RNA-Seq results. We will dissect both intrinsic and extrinsic (Th2 help) effects of KSRP deficiency on the immunophenotype and function of B cells concerning the character of humoral immune responses. Furthermore, the reasons for enhanced proliferation of KSRP-deficient CD4+ T cells as well as KSRP-mediated regulatory T cell function will be examined. The functional relevance of KSRP for pathogen killing activity of PMN will be monitored in a model of aspergillosis. Furthermore, we will perform rescue experiments in the asthma disease model to substantiate the suitability of KSRP for immunopharmacological intervention. Mice with a cell type-specific KSRP knockout will be generated to confirm key experiments from asthma studies.