Investigating lactate as an inflammatory early signal in ectopic lymphoid neogenesis and its translational impact in patients with autoimmune diseases

异位淋巴样结构（ELS）是指在慢性炎症部位形成的淋巴单核细胞簇，其获得次级淋巴器官的表型（即T和B淋巴细胞在离散区域分离，并分化成基质来源的滤泡树突状细胞网络）和功能（即生殖中心）特征。ELS的形成已在器官特异性自身免疫性疾病、实体瘤发生、慢性感染和移植排斥中描述。在干燥综合征（SS）的背景下，ELS在30/40%的患者中在唾液腺中发展，干燥综合征（SS）是第二常见的风湿性自身免疫性疾病，在英国的患病率在100，000 - 250，000之间，并且在女性中占优势（女性与男性比例为9：1）。在SS中，存在具有生发中心的ELS与更严重的疾病和16倍高的B细胞淋巴瘤风险相关，通常发生在受累腺体中。ELS形成的机制在很大程度上是未知的，但似乎是T和B细胞在慢性炎症组织内进行性积累和组织化的结果，由此促炎细胞因子（最值得注意的是IL-17和IL-17相关细胞因子，如IL-22）触发了光敏素/淋巴样趋化因子反馈环的激活。这些介质主要由CD 4 + T细胞释放，其对于与B细胞的同源相互作用和异位生发中心的发育也是至关重要的。在以前的工作中（以及目前正在Cell Metabolism重新审查的工作），我们证明了乳酸（其积累是慢性炎症组织的典型特征）通过特异性乳酸转运蛋白SCL 5A 12调节CD 4 + T细胞，促进Th 17细胞的扩增及其作为炎症部位的保留。因此，在本申请中，这是两所英国大学之间的合作，我们计划进行一系列全面的离体、体内和体外研究，目的是：1）研究在ELS+与ELS- SS患者中以及在对B细胞耗竭有反应者与无反应者中，CD 4 + T细胞中唾液腺和外周SLC 5A 12和IL-17的表达是否受到差异调节; 2）评估敲除SLC 5A 12的影响（遗传方法）和阻断SLC 5A 12的治疗潜力（药理学方法）在唾液腺ELS的诱导型鼠模型和SS唾液腺器官培养物中调节ELS; 3）剖析乳酸盐/SLC 5A 12对来自SS患者的CD 4 + T细胞的观察到的作用的潜在代谢途径。该建议将通过解决其对免疫病理学损伤发展的影响来强调连接代谢和免疫细胞功能的新的关键途径的重要性，所述免疫病理学损伤与SS极其相关并且是许多慢性自身免疫/炎性疾病的共同点。在短期内，预计如果成功，这项工作将为一个研究不足的领域和一种被认为是孤儿病的疾病SS带来新的知识，这种疾病具有明显的未满足的知识和临床需求。重要的是，我们的工作有可能影响以ELS形成为特征的其他医疗条件，包括癌症，慢性感染和移植排斥。我们还预计，通过在ELS小鼠模型和人体器官培养物中显示用我们开发的新型抗SLC 512单克隆抗体阻断乳酸/SLC 5A 12途径的“临床”和生物学功效，从长远来看，我们将为我们的研究转化为患者受益铺平道路。

Ectopic lymphoid-like structures (ELS) are defined as lymphomonocytic cell clusters forming at sites of chronic inflammation which acquire phenotypic (i.e. segregation of T and B lymphocytes in discrete areas with differentiation of networks of stromal-derived follicular dendritic cells) and functional (i.e germinal centres) features of secondary lymphoid organs. The formation of ELS has been described in organ-specific autoimmune conditions, solid tumorigenesis, in chronic infections and graft rejection. In the context of Sjogren's syndrome (SS), the second most common rheumatic autoimmune disease with a prevalence between 100,000-250,000 in UK and a predominance in women (female to male ration 9:1), ELS develop in the salivary glands in 30/40% of the patients. In SS, the presence of ELS with germinal centres is associated with a more severe disease and a 16-fold higher risk of B cell lymphoma, frequently arising in the affected glands. The mechanisms of ELS formation are largely unknown but appear to be the result of the progressive accumulation and organization of T and B cells within chronically inflamed tissue whereby the activation of the lymphotoxin/lymphoid chemokine feedback loop is triggered by pro-inflammatory cytokines, most notably IL-17 and IL-17 related cytokines such as IL-22. These mediators are primarily released by CD4+ T cells which are critical also for the cognate interaction with B cells and the development of ectopic germinal centres. In previous work (as well as work currently under re-review at Cell Metabolism) we demonstrated that lactate, whose accumulation is a typical feature of chronically inflamed tissues, modulate CD4+ T cells via the specific lactate transporter SCL5A12 promoting an expansion of Th17 cells and their retention as site of inflammation. Thus, in this application, which is a Partnership between 2 UK Universities, we plan to perform a series of comprehensive ex vivo, in vivo and in vitro studies with the aim to: 1) investigate whether salivary glands and peripheral SLC5A12 and IL-17 expression in CD4+ T-cells is differentially regulated in ELS+ vs ELS- SS patients and in responders vs non-responders to B cell depletion; 2) assess the impact of knocking out SLC5A12 (genetic approach) and the therapeutic potential of blocking SLC5A12 (pharmacological approach) in modulating ELS in an inducible murine model of salivary gland ELS and in SS salivary gland organ cultures; 3) dissect the metabolic pathways underlying the observed effects of lactate/SLC5A12 on CD4+ T-cells from SS patients.Overall, this proposal will highlight the importance of a novel key pathway linking metabolism and immune cell function by addressing its impact on the development of immunopathology lesions which are extremely relevant to SS and common to many chronic autoimmune/inflammatory diseases. In the short term, it is envisaged that, if successful, this work will bring new knowledge to a poorly investigated field and to a condition, SS, which is considered an orphan disease with clear unmet knowledge and clinical needs. Importantly, our work has the potential to impact on other medical conditions characterised by the formation of ELS, including cancer, chronic infection and graft rejection. We also anticipate that by showing "clinical" and biological efficacy of blocking the lactate/SLC5A12 pathway with a novel anti-SLC512 monoclonal antibody - which we developed - in a murine model of ELS and in human organ cultures, in the long term we will pave the way towards translation of our research towards patient benefit.