食物不耐受与慢性肾脏疾病及风湿性疾病的关系

食物不耐受是国内外研究的热点,其发生率在逐年上升,但目前在许多方面尚存在争议.研究食物不耐受的概念界定、发病机制、诊断、治疗及与肾病综合征、IgA肾病、类风湿性关节炎等常见肾脏疾病及风湿性疾病相关性具有重要意义.     

Are psoriasis and psoriatic arthritis the same disease? The IL-23/IL-17 axis data

Psoriatic arthritis (PsA) is a psoriasis (Ps)-associated inflammatory joint disease that affects peripheral joints, entheses, spine, and eyes. PsA and Ps are likely to be the same disease. PsA develops in nearly 70% of patients with Ps, and the hallmark of the disease is bone erosions and bone formation. Both innate and adaptive immunity appear to contribute to pathogenesis of PsA and Ps. Trauma may be a trigger factor for both PsA and Ps. The same T cell clones were reported to be present in both synovial tissues and skin lesions suggesting that a common antigen drives T cell immune response in the joints and skin lesions of patients with PsA. The IL-23/IL-17 axis plays a critical pathogenic role for both PsA and Ps, and biologics neutralizing IL-17A or IL-23/IL-12 are effective therapies for PsA and Ps. The differential expression of Th17 cytokines IL-17 and IL-22 at various sites could explain the different manifestations of the disease. IL-17 is highly expressed in peripheral joints and skin lesions and causes bone erosions. IL-22 is highly expressed in skin lesions and entheses, not peripheral joints, and cause bone formation. Finally, mannan from baker's yeast caused PsA-like arthritis and Ps-like skin lesions that were blocked by IL-17 treatment. These data suggest that PsA and Ps are likely to be the same disease exhibiting different manifestations depending on the local cytokine production.     

99Tc-亚甲基二膦酸盐对胶原诱导性关节炎大鼠骨侵蚀的治疗作用

目的：观察99锝-亚甲基二膦酸盐(99technetium-methylenediphosphonate,99Tc-MDP)注射液对胶原诱导性关节炎（collagen-induced arthritis, CIA）大鼠模型骨侵蚀的治疗作用,探讨其治疗骨侵蚀的有效作用成分及可能的作用机制。方法：建立CIA大鼠关节炎模型,分为模型组、帕米膦酸二钠组、MDP组和99Tc-MDP组,关节炎指数评价关节肿胀程度;放射学评分评价骨质破坏情况;HE染色观察关节病理组织形态学变化;ELISA检测血清中核因子κB受体活化因子配体（receptor activator of NF-κB ligand,RANKL）、骨保护素（osteoprotegerin,OPG）和Dickkopf-1（DKK-1）的水平。结果：99Tc-MDP组、MDP组、帕米膦酸二钠组关节炎指数评分、骨质破坏评分均低于模型对照组（P＜0.05）;99Tc-MDP组与帕米膦酸二钠组、MDP组相比,差异有统计学意义（P＜0.05）;99Tc-MDP组、MDP组、帕米膦酸二钠组血清OPG水平高于模型组（P＜0.05）,血清RANKL和DKK-1水平低于模型组（P＜0.05）;99Tc-MDP组血清OPG水平高于帕米膦酸二钠组和MDP组（P＜0.01）,RANKL和DKK-1水平低于帕米膦酸二钠组和MDP组（P＜0.01）,但帕米膦酸二钠组和MDP组间差异无统计学意义（P＞0.05）。结论：99Tc-MDP治疗CIA大鼠骨侵蚀的有效作用成分为99Tc与亚甲基二膦酸盐两者的螯合物,并且是通过促进OPG和抑制RANKL和DKK-1的表达发挥作用的。     

佐剂性关节炎大鼠肺功能变化与Foxp3、TGF-β1/Smads信号传导通路的相关性研究

目的:观察佐剂性关节炎(Adjuvant arthritis,AA)大鼠肺系数、肺功能变化、调节性T细胞及Foxp3、TGF-β1、Smad3、Smad7蛋白表达,探讨Foxp3与TGF-β/Smads信号传导通路在佐剂性关节炎大鼠肺功能降低中的可能作用机制。方法:将24只Wistar大鼠随机分为正常对照组和模型组,每组12只,向模型组大鼠右后足跖皮内注射弗氏完全佐剂0.1 ml致炎,复制成佐剂性关节炎模型。致炎48天后,观察两组大鼠足跖肿胀度及关节炎指数(AI),计算两组大鼠肺系数,检测大鼠肺功能,测定调节性T细胞百分率,HE染色观察肺病理学改变,免疫组化染色观察Foxp3、TGF-β1、Smad3、Smad7蛋白表达情况。结果:①与正常对照组相比,AA模型组大鼠足跖肿胀度、AI、肺系数、1秒内平均呼气流量(FEV1/FVC)、肺泡炎积分、TGF-β1及Smad3蛋白表达明显升高(P0.01);用力肺活量(FVC)、25%肺活量的最大呼气流量(FEF25)、50%肺活量的最大呼气流量(FEF50)、75%肺活量的最大呼气流量(FEF75)、最大呼气中期流量(MMF)、用力最大呼气流量(PEF)、肺动态顺应性(Cldyn)、CD4+T细胞、CD25+T细胞、CD4+CD25+T细胞百分率、Foxp3蛋白及Smad7蛋白表达显著降低(P0.01)。②Spearman相关分析可知,AA大鼠肺功能参数中FEF50、MMF与足跖肿胀度呈负相关,MMF与肺系数呈负相关,Cldyn与TGF-β1蛋白积分光密度值呈负相关;FEF50、MMF与关节炎指数呈正相关,FEF75与肺系数呈正相关,FEV1/FVC与Foxp3蛋白表达染色指数、Foxp3蛋白积分光密度值呈正相关(P0.05或P0.01)。结论:AA大鼠在足跖肿胀度、关节炎指数升高的同时出现肺功能的下降,提示可能是致炎后炎症的持续、发展而出现慢性炎症反应导致肺的损伤(肺间质纤维化),而肺功能的下降与Foxp3、Smad3、Smad7、TGF-β1蛋白表达呈相关性,说明转录因子Foxp3和TGF-β1/Smads信号传导通路共同参与其作用机制。     

Unconventional T‐cell recognition of an arthritogenic epitope of proteoglycan aggrecan released from degrading cartilage

It has been proposed that peptide epitopes bind to MHC class II molecules to form distinct structural conformers of the same MHC II–peptide complex termed type A and type B, and that the two conformers of the same peptide–MHC II complex are recognized by distinct CD4 T cells, termed type A and type B T cells. Both types recognize short synthetic peptides but only type A recognize endosomally processed intact antigen. Type B T cells that recognize self peptides from exogenously degraded proteins have been shown to escape negative selection during thymic development and so have the potential to contribute to the pathogenesis of autoimmunity. We generated and characterized mouse CD4 T cells specific for an arthritogenic epitope of the candidate joint autoantigen proteoglycan aggrecan. Cloned T‐cell hybridomas specific for a synthetic peptide containing the aggrecan epitope showed two distinct response patterns based on whether they could recognize processed intact aggrecan. Fine mapping demonstrated that both types of T‐cell recognized the same core epitope. The results are consistent with the generation of aggrecan‐specific type A and type B T cells. Type B T cells were activated by supernatants released from degrading cartilage, indicating the presence of antigenic extracellular peptides or fragments of aggrecan. Type B T cells could play a role in the pathogenesis of proteoglycan‐induced arthritis in mice, a model for rheumatoid arthritis, by recognizing extracellular peptides or protein fragments of joint autoantigens released by inflamed cartilage.     

沉默TREM-2对类风湿关节炎成纤维样滑膜细胞迁移和侵袭的影响

 目的: 应用RNA干扰(RNAi)技术沉默类风湿关节炎成纤维样滑膜细胞(RA-FLS)髓样细胞触发受体2(TREM-2)的表达,探讨TREM-2基因沉默对RA-FLS迁移和侵袭能力的影响及其相关机制。方法: 向RA-FLS转染特异性的TREM-2 siRNA,利用RT-PCR法和Western blot法检测沉默效果;CCK-8法检测各组细胞生长情况;Transwell小室测定细胞的迁移和侵袭能力;ELISA法检测细胞MMP-2和MMP-9的分泌水平;Western blot法分析沉默TREM-2基因对细胞PI3K/AKT通路的影响。结果: TREM-2 siRNA能显著降低RA-FLS中TREM2 mRNA和蛋白的表达(P<0.05)。沉默TREM-2基因后,各时点各组细胞的活力未见明显差异;特异性干扰组RA-FLS的迁移细胞数目与空白组和control siRNA组相比明显增多(P<0.05);TREM-2 siRNA组侵袭细胞数目相比空白组和control siRNA组明显增多(P<0.05);TREM-2 siRNA干扰后RA-FLS分泌的MMP-2显著增加(P<0.05)而MMP-9未见明显变化;特异性转染后的RA-FLS相对于对照组PI3K/AKT的磷酸化水平显著增强(P<0.05)。结论: TREM-2可能通过调节PI3K/AKT通路的活化对RA-FLS的迁移和侵袭能力发挥着重要作用。     

Th17 lymphocyte-dependent degradation of joint cartilage by synovial fibroblasts in a humanized mouse model of arthritis and reversal by secukinumab

How T-helper (Th) lymphocyte subpopulations identified in synovial fluid from patients with juvenile idiopathic arthritis (JIA) (Th17, classic Th1, or nonclassic Th1) drive joint damage is of great interest for the possible use of biological drugs that inhibit the specific cytokines. Our objective was to clarify the role of such Th subpopulations in the pathogenesis of articular cartilage destruction by synovial fibroblasts (SFbs), and the effect of Th17 blockage in an animal model. SFbs were isolated from healthy subjects and patients with JIA, and peripheral blood Th lymphocytes subsets were obtained from healthy subjects. Fragments of human cartilage from healthy subjects in a collagen matrix containing JIA or normal SFbs grafted underskin in SCID mice were used to measure cartilage degradation under the effects of Th supernatants. JIA SFbs overexpress MMP9 and MMP2 and Th17 induce both MMPs in normal SFbs, while nonclassic Th1 upregulate urokinase plasminogen activator (uPA) activity. In vitro invasive phenotype of normal SFbs is stimulated with conditioned medium of Th17 and nonclassic-Th1. In the in vivo “inverse wrap” model, normal SFbs stimulated with supernatants of Th17-lymphocytes and nonclassic Th1 produced a cartilage invasion and degradation similar to JIA SFbs. Secukinumab inhibits the cartilage damage triggered by factors produced by Th17.     

Immune checkpoints and the regulation of tolerogenicity in dendritic cells: Implications for autoimmunity and immunotherapy

The immune system is responsible for defending the host from a large variety of potential pathogens, while simultaneously avoiding immune reactivity towards self-components. Self-tolerance has to be tightly maintained throughout several central and peripheral processes; immune checkpoints are imperative for regulating the immunity/tolerance balance. Dendritic cells (DCs) are specialized cells that capture antigens, and either activate or inhibit antigen-specific T cells. Therefore, they play a key role at inducing and maintaining immune tolerance. DCs that suppress the immune response have been called tolerogenic dendritic cells (tolDCs). Given their potential as a therapy to prevent transplant rejection and autoimmune damage, several strategies are under development to generate tolDCs, in order to avoid activation and expansion of self-reactive T cells. In this article, we summarize the current knowledge relative to the main features of tolDCs, their mechanisms of action and their therapeutic use for autoimmune diseases. Based on the literature reviewed, autologous antigen-specific tolDCs might constitute a promising strategy to suppress autoreactive T cells and reduce detrimental inflammatory processes.