Investigating paclitaxel treatment in a pre-clinical model of Schistosoma-pulmonary hypertension

项目摘要/摘要 认识炎症在肺动脉高压发病机制中的重要作用 (PAH)是由于有证据表明自身免疫和传染病与 PAH；炎症可导致实验性肺动脉高压(PH)；血管周围炎症 存在于人类PAH的病理学和PH的动物模型中。然而，无论炎症是因果关系，还是 放大器的替代触发机制，或一种附带现象仍不清楚。关于这一角色的先前研究 T细胞在疾病发病机制中产生的数据与PAH的相关性尚不清楚：Th2和Th17细胞 对曲霉菌暴露和慢性低氧小鼠分别有害，而调节性T细胞(Tregs) 对使用SU5416或野百合碱治疗的大鼠具有保护作用。这些数据的转换应用是 慢性缺氧模型中有限的炎症和不清楚的炎症与 血管重塑。我们建议用相关的抗原来询问一个模型系统，该抗原可以激活特定的 2型免疫；血管周围的隔室，其中有抗原摄取和提呈，细胞增殖 以及转化生长因子-β-1导致肺动脉重塑的分子机制。我们 利用由曼氏血吸虫寄生虫触发的小鼠模型，复制关键的表型 可能是世界范围内PAH最常见的原因。我们的建议旨在确定抗原的确切作用- 作为IL-4和IL-13来源的特定CD4T细胞；这个群体是如何产生、扩大和激活的；以及 对单核细胞募集和转化生长因子-β激活的影响。我们假设接触到血吸虫 鸡蛋抗原导致克隆性Th2CD4T细胞激活和增殖，导致产生 IL-4和IL-13；这种典型的Th2反应招募Ly6C+单核细胞，导致转化生长因子-β驱动的PH。我们的 总体目标是确定血吸虫-PH发病的分子机制； 确定预防这种寄生虫病的免疫疗法，如疫苗接种的方法； 在炎症级联反应中更广泛地确定新的治疗靶点，这也可能适用于 其他炎症驱动的PAH病因。具体目标1是确定T细胞IL-4和IL-13驱动 血吸虫引起的炎症导致转化生长因子-β活化和PH。为此，我们将调查 用一系列系统的方法研究血吸虫-PH中Th2激活的CD4T细胞的必要性和充分性 以缺陷小鼠和免疫重建为对象的实验，以精确确定CD4来源的IL-4/IL-4- 13是LY6C+单核细胞募集和过度产生活性转化生长因子-β-1从而导致PH的关键。 具体目标2是确定由抗原提呈细胞摄取的血吸虫抗原(S) 在血吸虫PH中激活致病的、克隆性的IL-4/IL-13产生的CD4T细胞。为了实现这一目标，我们将 识别特定的血吸虫致病抗原；细胞摄取、加工和呈现血吸虫 用于激活CD4T细胞的抗原；以及指示克隆选择的CD4T细胞受体(TCR)谱系。

PROJECT SUMMARY / ABSTRACT The recognition that inflammation has important roles in the pathogenesis of pulmonary arterial hypertension (PAH) arises from evidence that autoimmune and infectious diseases are associated with the development of PAH; inflammation can generate experimental pulmonary hypertension (PH); and perivascular inflammation is present in the pathology of human PAH and animal models of PH. However, whether inflammation is causal, an amplifier of alternative triggering mechanisms, or an epiphenomenon remains unclear. Prior studies on the role of T cells in disease pathogenesis have generated data of unclear relevance to PAH: Th2 and Th17 cells are detrimental in Aspergillus-exposed and chronically hypoxic mice, respectively, while regulatory T cells (Tregs) are protective in rats treated with SU5416 or monocrotaline. The translational application of these data is hampered by limited inflammation in the chronic hypoxia model and unclear mechanisms linking inflammation to vascular remodeling. We propose to interrogate a model system with a relevant antigen that activates specific Type 2 immunity; a perivascular compartment in which there is antigen uptake and presentation, cell proliferation and recruitment; and molecular mechanisms involving TGF-β1 resulting in pulmonary artery remodeling. We employ a mouse model triggered by the parasite Schistosoma mansoni, which reproduces key phenotypes of likely the most common cause of PAH worldwide. Our proposal seeks to identify the precise role of antigen- specific CD4 T cells as the source of IL-4 and IL-13; how this population arises, expands, and is activated; and its impact on monocyte recruitment and TGF-β activation. We hypothesize that exposure to Schistosoma egg antigens results in clonogenic Th2 CD4 T cell activation and proliferation, leading to production of IL-4 and IL-13; this prototypic Th2 response recruits Ly6C+ monocytes causing TGF-β-driven PH. Our overall goals are to determine the molecular mechanisms underlying the pathogenesis of Schistosoma-PH; identify approaches to develop immunotherapies, such as vaccination, against this parasitic disease; and to more broadly identify novel therapeutic targets in the inflammatory cascade, which may also be applicable to other inflammation-driven PAH etiologies. Specific Aim 1 is to determine that T cell IL-4 and IL-13-driven inflammation caused by Schistosoma leads to TGF-β activation and PH. In this Aim we will investigate the necessity and sufficiency of Th2-activated CD4 T cells in Schistosoma-PH using a systematic series of experiments with deficient mice and immune reconstitution, to precisely determine whether CD4-derived IL-4/IL- 13 is critical for Ly6C+ monocyte recruitment and the overproduction of active TGF-β1 which results in PH. Specific Aim 2 is to determine the Schistosoma antigen(s) taken up by antigen presenting cells that activate pathogenic, clonogenic IL-4/IL-13 producing CD4 T cells in Schistosoma-PH. In this Aim we will identify specific pathogenic Schistosoma antigens; the cells taking up, processing and presenting Schistosoma antigens to activate CD4 T cells; and the CD4 T cell receptor (TCR) repertoire indicative of clonal selection.