Development of tibulizumab,a tetravalent bispecific antibody targeting BAFF and IL-17A for the treatment of autoimmune disease

ABSTRACT

We describe a bispecific dual-antagonist antibody against human B cell activating factor (BAFF) and interleukin 17A (IL-17). An anti-IL-17 single-chain variable fragment (scFv) derived from ixekizumab (Taltz®) was fused via a glycine-rich linker to anti-BAFF tabalumab. The IgG-scFv bound both BAFF and IL-17 simultaneously with identical stoichiometry as the parental mAbs. Stability studies of the initial IgG-scFv revealed chemical degradation and aggregation not observed in either parental antibody. The anti-IL-17 scFv showed a high melting temperature (Tm) by differential scanning calorimetry (73.1°C), but also concentration-dependent, initially reversible, protein self-association. To engineer scFv stability, three parallel approaches were taken: labile complementary-determining region (CDR) residues were replaced by stable, affinity-neutral amino acids, CDR charge distribution was balanced, and a H44-L100 interface disulfide bond was introduced. The Tm of the disulfide-stabilized scFv was largely unperturbed, yet it remained monodispersed at high protein concentration. Fluorescent dye binding titrations indicated reduced solvent exposure of hydrophobic residues and decreased proteolytic susceptibility was observed, both indicative of enhanced conformational stability. Superimposition of the H44-L100 scFv (PDB id: 6NOU) and ixekizumab antigen-binding fragment (PDB id: 6NOV) crystal structures revealed nearly identical orientation of the frameworks and CDR loops. The stabilized bispecific molecule LY3090106 (tibulizumab) potently antagonized both BAFF and IL-17 in cell-based and in vivo mouse models. In cynomolgus monkey, it suppressed B cell development and survival and remained functionally intact in circulation, with a prolonged half-life. In summary, we engineered a potent bispecific antibody targeting two key cytokines involved in human autoimmunity amenable to clinical development.     

A novel heterodimeric cytokine consisting of IL-17 and IL-17F regulates inflammatory responses

CD4＋ helper T （TH） cells play crucial roles in immune responses. Recently a novel subset of TH cells, termed THIL-17, TH 17 or inflammatory TH （THi）, has been identified as critical mediators of tissue inflammation. These cells produce IL-17 （also called IL-17A） and IL-17F, two most homologous cytokines sharing similar regulations. Here we report that when overexpressed in 293T cells, IL-17 and IL-17F form not only homodimers but also heterodimers, which we name as IL-17A/F. Fully differentiated mouse THi cells also naturally secrete IL-17A/F as well as IL-17 and IL-17F homodimeric cytokines. Recombinant IL-17A/F protein exhibits intermediate levels of potency in inducing IL-6 and KC （CXCL 1） as compared to homodimeric cytokines. IL-17A/F regulation of IL-6 and KC expression is dependent on IL-17RA and TRAF6. Thus, IL-17A/F cytokine represents another mechanism whereby T cells regulate inflammatory responses and may serve as a novel target for treating various immune-mediated diseases.     

重组人IL-17A和IL-17F的制备方法及活性测定

人IL-17A和IL-17F具有很高的同源性,在炎症性疾病、自身免疫性疾病和肿瘤中都发挥着重要的作用,是当前研究的热点.应用原核表达系统在大肠杆菌BL21(DE3)中高效表达了人IL-17A和IL-17F;经培养条件的优化,未发现可溶性目的蛋白的表达,免疫印记分析显示,重组蛋白位于包涵体中;对包涵体进行洗涤、凝胶过滤层析纯化和柱上复性,获得重折叠的可溶性蛋白;随后用SDS-PAGE对蛋白样品进行了纯度分析、采用免疫印记和质谱的方法鉴定蛋白产物成分、用ME3T3-E1和RAW264.7两个细胞株对IL-17A、IL-17F的生物学活性进行测定.结果显示,柱上复性的方法制备的谊重组蛋白具有较高的纯度和活性.建立的重组人IL-17A和IL-17F的制备方法可为相关研究中细胞因子的大量应用提供参考.     

Discovery of a potent and selective c-Kit inhibitor for the treatment of inflammatory diseases

A potent and selective c-Kit inhibitor 20 was identified through a structure–activity relationship study. In an in vivo mouse model of mast cell activation, 20 blocked the SCF-induced histamine release with an EC₅₀ of 26 nM.     

Simultaneous targeting of TNF and Ang2 with a novel bispecific antibody enhances efficacy in an in vivo model of arthritis

Despite the clinical success of anti-tumor necrosis factor (TNF) therapies in the treatment of inflammatory conditions such as rheumatoid arthritis, Crohn disease and psoriasis, full control of the diseases only occurs in a subset of patients and there is a need for new therapeutics with improved efficacy against broader patient populations. One possible approach is to combine biological therapeutics, but both the cost of the therapeutics and the potential for additional toxicities needs to be considered. In addition to the various mediators of immune and inflammatory pathways, angiogenesis is reported to contribute substantially to the overall pathogenesis of inflammatory diseases. The combination of an anti-angiogenic agent with anti-TNF into one molecule could be more efficacious without the risk of severe immunosuppression. To evaluate this approach with our Zybody technology, we generated bispecific antibodies that contain an Ang2 targeting peptide genetically fused to the anti-TNF antibody adalimumab (Humira®). The bispecific molecules retain the binding and functional characteristics of the anti-TNF antibody, but with additional activity that neutralizes Ang2. In a TNF transgenic mouse model of arthritis, the bispecific anti-TNF-Ang2 molecules showed a dose-dependent reduction in both clinical symptoms and histological scores that were significantly better than that achieved by adalimumab alone.     

Simultaneous targeting of TNF and Ang2 with a novel bispecific antibody enhances efficacy in an in vivo model of arthritis

Despite the clinical success of anti-tumor necrosis factor (TNF) therapies in the treatment of inflammatory conditions such as rheumatoid arthritis, Crohn disease and psoriasis, full control of the diseases only occurs in a subset of patients and there is a need for new therapeutics with improved efficacy against broader patient populations. One possible approach is to combine biological therapeutics, but both the cost of the therapeutics and the potential for additional toxicities needs to be considered. In addition to the various mediators of immune and inflammatory pathways, angiogenesis is reported to contribute substantially to the overall pathogenesis of inflammatory diseases. The combination of an anti-angiogenic agent with anti-TNF into one molecule could be more efficacious without the risk of severe immunosuppression. To evaluate this approach with our Zybody technology, we generated bispecific antibodies that contain an Ang2 targeting peptide genetically fused to the anti-TNF antibody adalimumab (Humira®). The bispecific molecules retain the binding and functional characteristics of the anti-TNF antibody, but with additional activity that neutralizes Ang2. In a TNF transgenic mouse model of arthritis, the bispecific anti-TNF-Ang2 molecules showed a dose-dependent reduction in both clinical symptoms and histological scores that were significantly better than that achieved by adalimumab alone.     

靶定IL-17 治疗类风湿关节炎研究进展

IL-17作为前炎症因子参与类风湿关节炎,系统性红斑狼疮等自身免疫性疾病的病理过程。它主要由CD4+T细胞的一个亚群--Th17细胞分泌释放。目前,IL-17在类风湿关节炎的病理过程中的作用引起了医学界广泛的关注,抗IL-17A抗体已经生产并进入临床实验,用于治疗类风湿关节炎、银屑病关节炎等疾病。但其在类风湿关节炎病理过程中的作用尚需进一步研究,其有效性亦尚需进一步探讨。本文主要针对IL-17家族的各个亚型的表达、调控、生物学作用及与类风湿关节炎发病的关系进行阐述,为类风湿关节炎的治疗提供新的思路。     

Characterization of novel anti-IL-26 neutralizing monoclonal antibodies for the treatment of inflammatory diseases including psoriasis

ABSTRACT

Interleukin (IL)-26, known as a Th17 cytokine, acts on various cell types and has multiple biological functions. Although its precise role still remains to be elucidated, IL-26 is suggested to be associated with the pathology of diverse chronic inflammatory diseases such as psoriasis, inflammatory bowel diseases and rheumatoid arthritis. To develop novel neutralizing anti-human IL-26 monoclonal antibodies (mAbs) for therapeutic use in the clinical setting, we immunized mice with human IL-26 protein. Hybridomas producing anti-IL-26 mAbs were screened for various in vitro functional assays, STAT3 phosphorylation and antibiotic assays. Although the IL-20RA/IL-10RB heterodimer is generally believed to be the IL-26 receptor, our data strongly suggest that both IL-20RA-dependent and -independent pathways are involved in IL-26-mediated stimulation. We also investigated the potential therapeutic effect of anti-IL-26 mAbs in the imiquimod-induced psoriasis-like murine model using human IL-26 transgenic mice. These screening methods enabled us to develop novel neutralizing anti-human IL-26 mAbs. Importantly, administration of IL-26-neutralizing mAb did not have an effect on the antimicrobial activity of IL-26. Taken together, our data strongly suggest that our newly developed anti-human IL-26 mAb is a potential therapeutic agent for the treatment of diverse chronic inflammatory diseases including psoriasis.     

The role of interleukin-17 in bone metabolism and inflammatory skeletal diseases

The balance between osteoblast-dependent bone formation and osteoclast-dependent bone resorption maintains bone homeostasis. In inflammatory conditions, this balance shifts toward bone resorption, causing osteolytic bone lesions observed in rheumatoid arthritis and periodontitis. A recently discovered family of cytokine IL-17 is widely reported to mediate diverse inflammatory processes. During the last decade, novel roles for IL-17 in skeletal homeostasis have been discovered indicating the potential importance of this cytokine in bone metabolism. This review will summarize and discuss the involvement of IL-17 during bone homeostasis in both physiologic and pathologic conditions. A better understanding of the role of IL-17 in skeletal systems warrants an advance in bone biology, as well as development of therapeutic strategies against bone-lytic diseases, such as rheumatoid arthritis and periodontitis. [BMB Reports 2013; 46(10): 479-483]     

早产产妇血清和胎盘IL-17、IL-21及IL-22表达水平与新生儿感染发生的相关性研究

摘要 目的：分析早产产妇血清和胎盘IL-17、IL-21及IL-22表达水平与新生儿感染发生的相关性。方法：选择2020年7月至2021年12月在我院分娩的120例早产产妇作为观察组,另选同期的120例足月分娩产妇作为对照组。检测两组产妇血清和胎盘IL-17、IL-21及IL-22表达水平,根据观察组产妇分娩的新生儿是否发生感染,分为感染组和非感染组,比较两组母体血清和胎盘IL-17、IL-21及IL-22表达水平,使用多因素Logistic回归分析和受试者工作特征曲线(ROC)分析早产产妇血清和胎盘IL-17、IL-21及IL-22与新生儿感染的关系。结果：观察组血清和胎盘IL-17、IL-21及IL-22表达水平均高于对照组（P＜0.05）;感染组母体血清和胎盘IL-17、IL-21及IL-22表达水平均高于非感染组（P＜0.05）;经多因素Logistic回归分析,早产产妇血清和胎盘IL-17、IL-21及IL-22均是新生儿感染发生的独立预测因素（P＜0.05）;经Pearson相关性分析,早产产妇血清IL-17与胎盘IL-17 mRNA、血清IL-21与胎盘IL-21 mRNA、血清IL-22与胎盘IL-22 mRNA均呈正相关（P＜0.05）;经ROC曲线分析,早产产妇血清IL-17、IL-21联合IL-22预测新生儿感染发生的AUC为0.910。结论：早产产妇血清和胎盘IL-17、IL-21及IL-22表达水平升高均与新生儿感染发生密切相关,其中血清IL-17、IL-21联合IL-22预测新生儿感染的效能较高,值得进一步研究应用。     

Genus Ziziphus for the treatment of chronic inflammatory diseases

Natural products and traditional medicine are rich sources for developing therapeutics for chronic inflammatory diseases. However, the way from natural products/traditional medicines to Western pharmaceutical practices is not always straightforward. According to the World Health Organization (WHO), chronic diseases are the greatest threat to human health. 3 of 5 people die due to chronic inflammatory disorders worldwide like chronic respiratory diseases, stroke, cardiovascular diseases, cancer, diabetes, and obesity. Various nonsteroidal anti-inflammatory drugs (NSAIDs) are used to reduce inflammation and pain, but there are many side effects of these drugs' administration. Medicinal plants have therapeutic anti-inflammatory effects with low or no side effects. Ziziphus plant species are generally safe and not toxic to humans. Many studies on the Ziziphus species have shown that their therapeutic properties are attributed to the roots, leaves and fruits. Unfortunately, Ziziphus species from different regions worldwide with anti-inflammatory properties have not been documented in a single review paper. Therefore, it is crucial to establish ethnobotanical knowledge and applications of Ziziphus species against chronic inflammatory diseases. The current article exhaustively reviews phytochemical profile, pharmacological studies, toxicological effects, and ethnobotanical uses of Genus Ziziphus in chronic anti-inflammatory diseases. The present review article also highlights the most promising experimental data on Ziziphus extracts and pure compounds active in clinical trials and animal models of chronic inflammatory diseases. This review would be a valuable resource for contemporary researchers in the field to understand the promising role of the Ziziphus genus in chronic inflammatory disorders.     

重组人白细胞介素－6与肿瘤坏死因子突变体融合蛋白的构建及表达

针对肿瘤坏死因子（ＴＮＦ）在肿瘤治疗剂量下产生的严重毒副作用及一些肿瘤细胞上白细胞介素－６（ＩＬ－６）受体明显增高的事实,根据ＴＮＦ结构与功能研究的最新信息,利用ＰＣＲ技术,对人ＴＮＦα基因进行了改造,并将其与人ＩＬ－６成熟肽编码区ｃＤＮＡ通过人工接头进行融合。融合蛋白在大肠杆菌中表达后,Ｗｅｓｔｅｒｎｂｌｏｔ分析表明,分子量约为３７ｋＤ;活性检测结果证实,该融合蛋白兼具有ＴＮＦ抗肿瘤活性和结合ＩＬ－６受体的能力,在高表达ＩＬ－６受体的人骨髓瘤细胞上测得的细胞毒活性较同样位点突变的ＴＮＦ高约３倍。     

寻常型银屑病患者血清IL-17、IL-18、VEGF的表达及与病情严重程度的相关性研究

目的:探讨寻常型银屑病患者血清白介素17(IL-17)、白介素18(IL-18)、血管内皮生长因子(VEGF)的表达及与病情严重程度的相关性。方法:选取2015年8月到2017年4月在我院接受治疗的寻常型银屑病患者86例为研究组,另选取同期在我院体检结果为健康的志愿者40例作为健康对照组,并根据临床症状和病情变化对研究组患者进行分组,其中进行期银屑病组32例,静止期银屑病组24例,退行期银屑病组30例。对比研究组和健康对照组血清中IL-17、IL-18、VEGF水平,对比不同严重程度的寻常型银屑病患者血清中IL-17、IL-18、VEGF水平和PASI评分,采用Spearman相关性分析IL-17、IL-18、VEGF的表达与PASI评分的相关性。结果:研究组患者血清中的IL-17、IL-18、VEGF水平显著高于健康对照组(P0.05),进行期银屑病组患者血清中IL-17、IL-18、VEGF水平和PASI评分显著高于静止期银屑病组和退行期银屑病组,静止期银屑病组患者血清中IL-17、IL-18、VEGF水平和PASI评分显著高于退行期银屑病组(P0.05),Spearman相关性分析结果显示,研究组患者血清中IL-17、IL-18、VEGF水平与PASI评分均呈正相关(P0.05)。结论:寻常型银屑病患者血清中IL-17、IL-18、VEGF水平异常升高,且其水平与病情严重程度有关,对上述三种指标进行监测有助于临床治疗寻常型银屑病。     

血清IL-17、IL-32、IL-33、IL-37联合检测对初治多发性骨髓瘤患者早期治疗反应性的预测价值

摘要 目的：探讨血清白细胞介素-17（IL-17）、白细胞介素-32（IL-32）、白细胞介素-33（IL-33）、白细胞介素-37（IL-37）联合检测对接受硼替佐米为基础一线治疗方案的初治多发性骨髓瘤（MM）患者早期治疗反应性的预测价值。方法：选择2018年7月至2021年3月期间陕西省人民医院收治的初治MM患者176例为研究对象,所有患者均接受以硼替佐米为基础一线的治疗方案,根据早期治疗反应性分为敏感组（142例）和非敏感组（34例）;采用酶联免疫吸附法检测并比较两组血清IL-17、IL-32、IL-33、IL-37水平,并分析其联合检测对早期治疗反应性的预测价值。结果：敏感组治疗前血清IL-17、IL-32水平低于非敏感组,IL-33、IL-37水平高于非敏感组（P＜0.05）。多因素logistic回归分析显示,年龄≥65岁、血清IL-17≥29.70 pg/mL、IL-32≥63.02 ng/L、肿瘤分期III期是早期治疗反应性的危险因素（P＜0.05）,IL-33＞141.97 pg/mL、IL-37＞69.17 ng/L是保护因素（P＜0.05）。血清IL-17、IL-32、IL-33、IL-37联合检测预测早期治疗反应性的曲线下面积（AUC）为0.866（95%CI：0.801~0.972）。结论：年龄、肿瘤分期、血清IL-17、IL-32、IL-33、IL-37是MM患者早期治疗反应性的影响因素,联合检测血清IL-17、IL-32、IL-33、IL-37水平对接受硼替佐米为基础一线治疗方案的初治MM患者早期治疗反应性预测价值较高。     

IL-17A在呼吸道慢性炎症性疾病中的研究进展

白介素-17A(IL-17A)是一种促炎因子,是IL-17细胞因子家族中的一员。该家族的细胞因子分别被命名为IL-17A至IL-17F,IL-17A是该家族中最具代表性的成员,它能够促进炎症细胞释放多种趋化因子、细胞因子和抗菌肽等,诱导中性粒细胞的聚集和增殖,是连接固有免疫和适应性免疫的桥梁。IL-17A的家族细胞因子在很多肺部过敏性、自身免疫性甚至肿瘤性疾病的发生发展和宿主防御中发挥着关键作用,在哮喘、慢性阻塞性肺病(COPD)、囊性纤维化(CF)、结节病、支气管扩张等呼吸道慢性炎症性疾病中均存在异常表达,虽然在多种疾病中未能阐明IL-17A影响疾病发展的具体作用机制,但已证明其水平与疾病的发展存在关联,这不仅为研究相关疾病的发病机制提供了新的切入点,也为其新型治疗手段的研究提供了新的思路。本文就IL-17A在呼吸道慢性炎症性疾病中的研究进展进行综述。     

Cyclosporin A inhibits the production of IL-17 by memory Th17 cells from healthy individuals and patients with rheumatoid arthritis

Recent evidence from several studies indicated that IL-17-producing Th17 cells can represent the key effector cells in the induction and development of autoimmune disorders. Cyclosporine A (CsA) is a commonly used immunosuppressant to treat lots of autoimmune diseases including rheumatoid arthritis (RA). Here, we demonstrated that PBMCs and purified CD4⁺ T cells from healthy individuals and patients with RA could be induced to produce large amounts of IL-17 after stimulation with anti-CD3 plus anti-CD28 mAbs. Phenotypic analysis indicated that the majority of IL-17-producing cells were Th17 cells with memory phenotype. The addition of CsA into cell cultures significantly inhibited the IL-17 production by Th17 cells at protein and at mRNA levels. Compared to the PBMCs from normal individuals, PBMCs from the patients with RA produced higher levels of IL-17 that was also significantly inhibited by CsA both at protein and at mRNA levels. The mechanism might be the effect of CsA on the T cells activation because the expression of CD69 and CD25 molecules on T cells was markedly reduced in the presence of CsA. Taken together, these results demonstrated that CsA suppressed the IL-17 production and inhibited the Th17 cells differentiation from both healthy individuals and patients with RA.     

Therapeutic potency of crocin in the treatment of inflammatory diseases: Current status and perspective

Crocin is the major component of saffron, which is used in phytomedicine for the treatment of several diseases including diabetes, fatty liver, depression, menstruation disorders, and, of special interest in this review, inflammatory diseases. Promising selective anti-inflammatory properties of this pharmacological active component have been observed in several studies. Saffron has been shown to exert anti-inflammatory properties against several inflammatory diseases and can be used as a novel therapeutic agent for the treatment of inflammatory diseases either alone or in combination with other standard anti-inflammatory agents. This review summarizes the protective role of saffron and its pharmacologically active constituents in the pathogenesis of inflammatory diseases including digestive diseases, dermatitis, asthma, atherosclerosis, and neurodegenerative diseases for a better understanding and hence a better management of these diseases.     

依泽替米贝对胆囊结石患者血清TNF及IL-1水平影响

目的：探究依泽替米贝对胆囊结石患者血清TNF及IL-1 水平变化的影响。方法：选取2014 年8 月至2015 年2 月我院收治 的胆囊结石患者70 例,采用随机数字表随机分为两组,其中对照组35 例,给予溶石疗法等临床常规治疗;实验组35 例,在与对 照组相同的临床常规溶石治疗基础上加用依泽替米贝进行治疗。治疗结束后,比较两组患者胆囊结石数量、重量的差异以及血清 TNF及IL-1 水平变化。结果：①经治疗后实验组患者胆囊内结石平均数量（6.1± 2.5）,明显少于对照组（9.2± 2.7）,且差异有统计 学意义（t=2.269,P=0.037<0.05）;②经治疗后实验组患者胆囊内结石平均重量（0.17± 3.31）g 明显少于对照组（0.48± 3.04）g,且差 异有统计学意义（t=2.237,P=0.026<0.05）;③经治疗后实验组患者血清TNF水平为（15.93± 4.78）ng/mg,明显低于对照组（22.13± 5.17）ng/mg,且差异有统计学意义（t=2.501,P=0.036<0.05）;④经治疗后实验组患者血清IL-1 水平（63.41± 8.12）ng/mg 明显低于 对照组（89.60± 7.08）ng/mg,且差异有统计学意义（t=2.439,P=0.029<0.05）;⑤治疗后,实验组患者的治疗有效率明显高于对照组, 且差异具有统计学意义（t=2.321,P=0.034<0.05）。结论：依泽替米贝能有效减少结石数量和体积,缓解胆囊结石患者症状,有较好 的临床疗效,对临床治疗具有指导意义,值得临床应用和推广。     

阿尔茨海默病患者血清IL-10、IL-17、IL-33与肠道菌群相对丰度和认知功能的相关性分析

摘要 目的：分析阿尔茨海默病（AD）患者血清白介素（IL）-10、IL-17、IL-33与肠道菌群相对丰度和认知功能的相关性。方法：选择上海交通大学医学院附属第九人民医院老年科以及黄浦分院神经内科于2020年4月~2023年4月期间收治的AD患者 98例作为研究对象。根据临床痴呆评定量表（CDR）将AD患者分为轻度组（n=36）、中度组（n=39）、重度组（n=23）。对比三组患者的IL-10、IL-17、IL-33、肠道菌群相对丰度、认知功能评分。采用Pearson相关性分析AD患者血清IL-10、IL-17、IL-33与肠道菌群相对丰度和认知功能的相关性。结果：重度组、中度组的IL-17水平高于轻度组,且重度组高于中度组（P<0.05）。重度组、中度组IL-10、IL-33水平低于轻度组,且重度组低于中度组（P<0.05）。重度组、中度组的梭菌纲、厚壁菌门、梭菌科、梭菌目低于轻度组,且重度组低于中度组（P<0.05）。重度组、中度组的拟杆菌门、拟杆菌纲、拟杆菌目、产碱杆菌科高于轻度组,且重度组高于中度组（P<0.05）。重度组、中度组简易精神状态量表（MMSE）评分低于轻度组,且重度组低于中度组（P<0.05）。Pearson相关性分析结果显示,IL-10、IL-33与MMSE评分、厚壁菌门、梭菌纲、梭菌目、梭菌科呈正相关,与拟杆菌门、拟杆菌纲、拟杆菌目、产碱杆菌科呈负相关（P<0.05）。IL-17与MMSE评分、厚壁菌门、梭菌纲、梭菌目、梭菌科呈负相关,与拟杆菌门、拟杆菌纲、拟杆菌目、产碱杆菌科呈正相关（P<0.05）。结论：AD患者认知功能下降,血清IL-10、IL-17、IL-33水平异常变化,患者体内肠道菌群相对丰度异常,且IL-10、IL-17、IL-33水平与肠道菌群相对丰度、认知功能存在一定的相关性。     

Upregulation of IL-17A/F from human lung tissue explants with cigarette smoke exposure: implications for COPD

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory disorder marked by relative resistance to steroids. The IL-17 superfamily, which mediates cross-talk between the adaptive and innate immune systems, has been associated with diminished responses to steroids. Increasing evidence supports elevated IL-17 expression in the lung of COPD subjects. However, whether cells of the immune system (systemic) and/or local lung cells are contributing to the elevated IL-17 remains unclear. To address this issue, we utilized a human parenchymal lung tissue explant culture system with cigarette smoke exposure to investigate the expression of IL-17 and the mechanisms involved.

Methods

Parenchymal lung tissue removed from 10 non-COPD and 8 COPD patients was sectioned and cultured with different concentrations of cigarette smoke extract (CSE) for 3 or 6 hours. Tissue viability was evaluated by LDH (lactate dehydrogenase) in culture supernatants. Western blot and real-time PCR were performed to evaluate IL-17A/F expression. To investigate the mechanisms, pharmacological inhibitors for MAPK p38, ERK1/2, NF-κB and PI3K pathways were added into the culture media.

Results

No tissue damage was observed after the cigarette smoke exposure for 3 h or 6 h compared with the control media. At the protein level, the expression of both IL-17A (2.4 ± 0.6 fold) and IL-17 F (3.7 ± 0.7 fold) in the tissue from non-COPD subjects was significantly increased by 5% of CSE at 3 h. For COPD subjects, IL-17A/F expression were significantly increased only at 6 h with 10% of CSE (IL-17A: 4.2 ± 0.8 fold; IL-17 F: 3.3 ± 0.8 fold). The increased expression of IL-17A/F is also regulated at the mRNA level. The inhibitors for NF-κB and PI3K pathways significantly inhibited CSE-induced IL-17A/F expression from lung tissue of non-COPD subjects.

Conclusions

We found the evidence that the expression of both IL-17A and IL-17 F is increased by the cigarette smoke exposure in explants from both non-COPD and COPD subjects, supporting that local lung cells contribute IL-17 production. The elevated IL-17A/F expression is dependent on NF-κB and PI3K pathways. These observations add to the growing evidence which suggests that Th17 cytokines play a significant role in COPD.