Innate effects of beryllium on pulmonarydendritic cell function in chronic beryllium disease

 描述（由申请人提供）：慢性铍病（CBD）是一种导致纤维化和死亡的衰弱性进行性肺病。CBD仍然是一个重要的公共卫生问题，有超过100万工人处于危险之中。其特征在于肺中由铍（Be）特异性CD 4 + T细胞介导的肉芽肿性炎症。Be特异性CD 4 + T细胞应答的发展依赖于MHCII分子对T细胞的Be呈递，并且大多数Be特异性CD 4 + T细胞以HLA-DP限制性方式识别Be。在一种新的临床前模型中，暴露于Be的HLA-DP 2转基因（Tg）小鼠在没有添加佐剂的情况下在肺中产生Be特异性CD 4 + T细胞应答和肉芽肿性炎症。Be也具有有效的佐剂作用，我们假设Be刺激驱动Be特异性CD 4 + T细胞和CBD生成的先天途径。我们的初步数据表明，肺部暴露于Be后，细胞死亡发生，DNA被释放到肺部。单核细胞和嗜中性粒细胞被迅速募集到肺中，并且经典树突状细胞（cDC）在肺引流淋巴结（LDLN）中积累。在C57 BL/6小鼠中，Be暴露增强了通过先天途径对旁观者抗原的CD 4 + T细胞的启动。在MyD 88缺陷和DNA酶处理的WT小鼠中，Be诱导的对旁观者CD 4 + T细胞应答的影响受损。Be对CD 4 + T细胞应答的佐剂效应在缺乏TLR 2、TLR 4、TLR 7、Nlrp 3、Caspase-1和IL-1 R的小鼠中是完整的。然而，在Be暴露的TLR 9 KO小鼠中，LDLN中cDC的积累受损，这表明TLR 9参与了MyD 88依赖性作用。然而，可能涉及多个DNA传感器，因为Be对CD 4 + T细胞的佐剂效应在Be暴露的TLR 9 KO小鼠中没有完全受损。cDC活化和足够的共刺激可能是控制病理性Be特异性CD 4 + Th 1效应子应答和CBD产生的关键检查点。因此，靶向cDC中的这些途径可能会影响疾病的严重程度。我们的中心假设是，铍诱导的DNA与肺中的DNA敏感受体结合，增强cDC功能并驱动铍特异性CD 4 + Th 1应答的发展，靶向这些途径将改善CBD的肺部疾病。在目标1中，我们将正式测试cDC和单核细胞在HLA-DP 2 Tg小鼠中Be特异性CD 4 + T细胞应答的产生中的作用。在目标2中，我们将确定DNA诱导的先天性信号传导途径在Be对cDCs和CD 4 + T细胞应答的佐剂效应中的作用。在目的3中，我们将分析所需的先天受体途径在CBD的新型HLA-DP 2 Tg小鼠模型中驱动Be特异性CD 4 + T细胞应答和肺病理学的作用。这些研究将填补我们对Be诱导的免疫系统先天和适应性臂激活之间联系的理解中的关键知识空白，这有望导致新的治疗靶点，特别是在治疗选择有限的疾病中。

 DESCRIPTION (provided by applicant): Chronic beryllium disease (CBD) is a debilitating, progressive lung disease that leads to fibrosis and death. CBD remains an important public health concern with more than 1 million workers at risk. It is characterized by granulomatous inflammation that is mediated by beryllium (Be)-specific CD4+ T cells in the lung. The development of a Be-specific CD4+ T cell response depends on presentation of Be to T cells by MHCII molecules, and the majority of Be-specific CD4+ T cells recognize Be in an HLA-DP-restricted manner. In a novel preclinical model, HLA-DP2 transgenic (Tg) mice exposed to Be generate Be-specific CD4+ T cell responses and granulomatous inflammation in the lung in the absence of added adjuvant. Be also has potent adjuvant effects, and we hypothesize that Be stimulates innate pathways that drive generation of Be-specific CD4+ T cells and CBD. Our preliminary data show that after pulmonary exposure to Be, cell death occurs, and DNA is released into the lung. Monocytes and neutrophils are rapidly recruited to the lung, and classical dendritic cells (cDCs) accumulate in the lung-draining lymph nodes (LDLNs). In C57BL/6 mice, Be exposure enhances priming of CD4+ T cells to bystander antigens through innate pathways. In MyD88-deficient and DNase-treated WT mice, the Be-induced effects on bystander CD4+ T cell responses are impaired. The adjuvant effect of Be on CD4+ T cell responses is intact in mice that lack TLR2, TLR4, TLR7, Nlrp3, Caspase-1 and IL-1R. However in Be-exposed TLR9KO mice, accumulation of cDCs in the LDLNs is impaired, suggesting that TLR9 participates in the MyD88-dependent effects. However, multiple DNA sensors may be involved, because the adjuvant effects of Be on CD4+ T cells are not fully impaired in Be-exposed TLR9KO mice. cDC activation and adequate costimulation are likely critical checkpoints that control the generation of a pathological Be-specific CD4+ Th1 effector response and CBD. Accordingly, targeting these pathways in cDCs may impact disease severity. Our central hypothesis is that Be-induced DNA binds to DNA-sensing receptors in the lung, enhancing cDC function and driving the development of the Be-specific CD4+ Th1 response and that targeting these pathways will ameliorate lung disease in CBD. In Aim 1, we will formally test the role of cDCs and monocytes in the generation of Be-specific CD4+ T cell responses in HLA-DP2 Tg mice. In Aim 2, we will determine the role of DNA-induced innate signaling pathways in the adjuvant effects of Be on cDCs and CD4+ T cell responses. In Aim 3, we will analyze the effects of required innate receptor pathways in driving Be- specific CD4+ T cell responses and lung pathology in the novel HLA-DP2 Tg mouse model of CBD. These studies will fill a critical knowledge gap in our understanding of the link between Be-induced activation of innate and adaptive arms of the immune system that hopefully will lead to new therapeutic targets, particularly in a disease with limited treatments options.