TL1A:一个新的TNF家族成员

TL1A是肿瘤坏死因子超家族的一个新亚群。通过与受体DR3和DcR3/TR6的结合,既可诱导细胞凋亡,也能活化NF-ΚB。在淋巴细胞、单核细胞/巨噬细胞的活化和增殖,炎症反应的调节、机体的免疫应答以及动脉粥样硬化、炎症性肠病等疾病的发生、发展中起重要作用。     

The TL1A-DR3 Axis in Asthma: Membrane-Bound and Secreted TL1A Co-Determined the Development of Airway Remodeling

PurposeTumor necrosis factor-like ligand 1A (TL1A), especially its secreted form, has been shown to contribute to eosinophilic inflammation and mucus production, cardinal features of asthma, through its receptor, death receptor 3 (DR3). However, the role of the TL1A-DR3 axis in asthma, especially in terms of airway remodeling, has not yet been fully understood.MethodsThe present study investigated the expression and secretion of TL1A in the lung and human bronchial epithelial cells. DR3 small interfering RNA (siRNA), TL1A siRNA, and truncated plasmids were used respectively to identify the function of the TL1A-DR3 axis in vitro. To further validate the roles of the TL1A-DR3 axis in asthma, we collected airway biopsies and sputa from asthmatic patients and constructed a mouse model following rTL1A administration, DR3 knockdown, and TL1A knockout, the asthma-related inflammatory response and the pathological changes in airways were analyzed using various experimental methods. Associated signaling pathways downstream of TL1A knockout in the mouse model were analyzed using RNA sequencing.ResultsTL1A, especially its non-secreted form (nsTL1A) was involved in the remodeling process in asthmatics’ airways. Knockdown of TL1A or its receptor DR3 decreased the expression of fibrosis-associated protein in BEAS-2B cells. Reversely, overexpression of nsTL1A in airway epithelial cells facilitated the transforming growth factor-β-induced remodeling progress. In the asthma mouse model, activating the TL1A-DR3 axis contributes to airway inflammation, remodeling, and tissue destruction. Reciprocally, DR3 knockdown or TL1A knockout partly reverses airway remodeling in the asthma model induced by ovalbumin.ConclusionsOur results confirm differential TL1A expression (including its secreted and non-secreted form) in asthma, which modulates remodeling. The shared mechanism of action by which nsTL1A and secreted TL1A exert their effects on asthma development might be mediated via the nuclear factor-κB pathway. The TL1A-DR3 axis presents a promising therapeutic target in asthma.     

TL1A blocking ameliorates intestinal fibrosis in the T cell transfer model of chronic colitis in mice

Tumor necrosis factor like cytokine 1A (TL1A) is a member of the TNF superfamily. Accumulating evidence demonstrated the importance of TL1A in the pathogenesis of inflammatory bowel disease (IBD) and suggested a potential role of TL1A blocking in IBD therapy. Here we aimed to explore whether the anti-TL1A antibody could ameliorate intestinal inflammation and fibrosis in IBD. A T cell transfer model of chronic colitis was induced by intraperitoneal injection of CD4⁺CD45RB^high naive T cells isolated from either C57BL/6 wild type (WT) mice or LCK-CD2-Tl1a-GFP transgenic (L-Tg) mice into recombinase activating gene-1-deficient (RAG^?/?) mice. The colitis model mice were treated prophylactically or therapeutically with anti-Tl1a antibody or IgG isotype control. Haematoxylin and eosin staining (H&E staining), Masson's trichrome staining (MT staining) and sirius red staining were used to detect histopathological changes in colonic tissue; immunohistochemical staining was used to detect the expressions of collagen I, collagen III, TIMP1, vimentin, α-SMA and TGF-β1/Smad3. Results showed that anti-Tl1a antibody could reduce intestinal inflammation and fibrosis by inhibiting the activation of intestinal fibroblasts and reducing the collagen synthesis in the T cell transfer model of chronic colitis. The mechanism may be related to the inhibition of TGF-1/Smad3 signaling pathway.     

Ultrastructural findings and tumor necrosis factor-alpha and intercellular adhesion molecule-1 expression in psoriasis patients before and after oral cyclosporin A therapy

Elevated levels of proinflammatory cytokines, including tumor necrosis factor-alpha, are found in skin lesions and plasma of patients with psoriasis. Clinical improvement of psoriasis with cyclosporin A treatment is accompanied by downmodulation of proinflammatory epidermal cytokines. In this study to determine the effects of cyclosporin A on the ultrastructural changes and tumor necrosis factor-alpha and intercellular adhesion molecule-1 expression in psoriasis, biopsy specimens before and after cyclosporin A treatment were evaluated ultrastructurally and immunohistochemically. Ten patients were given 3-7.5 mg/kg oral cyclosporin A for 6 months. Before and after treatment full thickness of 4-mm punch biopsies were obtained from patients and from 6 healthy volunteers. Samples were processed for electron microscopic and immunohistochemical evaluation. The treatment was well tolerated with complete clinical improvement. The ultrastructural changes such as reduction of tonofilaments, dilatation of intercellular space, and interruption in lamina densa were recovered by cyclosporin A treatment. The increased staining intensity of tumor necrosis factor-alpha and intercellular adhesion molecule-1 on epidermal keratinocytes and endothelial cells was reduced after cyclosporin A therapy. Cyclosporin A treatment results in total normalization of the electron microscopic picture of psoriasis and its beneficial effect depends on the direct inhibition of tumor necrosis factor-alpha and consequently intercellular adhesion molecule-1.     

TL1A and DR3, a TNF family ligand-receptor pair that promotes lymphocyte costimulation, mucosal hyperplasia, and autoimmune inflammation

DR3 (TNFRSF25) is a member of the tumor necrosis factor receptor (TNFR) superfamily expressed primarily on lymphocytes and is a receptor for the TNF family cytokine TL1A (TNFSF15). DR3 costimulates T-cell activation, but it is unique among these receptors in that it signals through an intracytoplasmic death domain and the adapter protein TRADD (TNFR-associated death domain). TL1A costimulates T cells to produce a wide variety of cytokines and can promote expansion of activated and regulatory T cells in vivo. Studies in mice deficient in DR3 or TL1A or in animals treated with antibodies that block the activity of TL1A have revealed a specific role for DR3 in enhancing effector T-cell proliferation at the site of tissue inflammation in autoimmune disease models. DR3 appears to be required in autoimmune disease models dependent on a variety of different T-cell subsets and also invariant natural killer T (iNKT) cells. Chronic expression of TL1A induces a distinct interleukin-13-dependent pathology in the small intestine marked by goblet cell hyperplasia and other features associated with allergic and anti-parasitic responses. These studies suggest that TL1A may be a viable target for therapies designed to inhibit the T-cell-dependent component of diverse autoimmune diseases.     

New mechanisms of skin innate immunity: ASK1-mediated keratinocyte differentiation regulates the expression of beta-defensins, LL37, and TLR2

Epidermal keratinocytes differentiate and form a multilayered epidermis, which is the primary barrier between the body and the outer environment. As the epidermis is constantly exposed to a variety of microbial pathogens, its function of resisting microbial pathogens is vital. This characteristic feature is formed during differentiation. Immunohistochemical analysis revealed that the upper epidermis of normal human skin expresses beta-defensins 1-3 and LL37. We hypothesized that epidermal keratinocytes develop an innate immune barrier based on human beta-defensins (hBD) and LL37 during differentiation. To prove this, we introduced an active form of the apoptosis signal-regulating kinase-1 (ASK1), an intracellular regulator of keratinocyte differentiation, into cultured normal human keratinocytes. Transfection of this active form, ASK1-DeltaN, significantly enhanced the expression of hBD1-3 and LL37. In addition, a p38 inhibitor abolished this induction, indicating that the ASK1-p38 cascade regulates the expression of hBD1-3 and LL37. Furthermore, the ASK1-p38 pathway also regulated the expression of Toll-like receptor (TLR)2 in keratinocytes. Contact between S. aureus and keratinocytes resulted in the phosphorylation of p38 and induced the expression of hBD2 and hBD3. Moreover, the p38 inhibitor reduced this induction. In conclusion, the ASK1-p38 cascade regulates the innate immunity of the skin by forming an immune barrier consisting of hBD, LL37, and TLR2 during epidermal differentiation.     

Different expression of adhesion molecules and tetraspanins of monocytes of patients with atopic eczema

BACKGROUND: Atopic eczema (AE) and psoriasis vulgaris (Pso) represent the most frequent chronic inflammatory skin diseases, which have a high number of characteristics in common but differ in their clinical picture and immunological background. A shared feature of both AE and Pso is a high recruitment of distinct proinflammatory cells from the blood into the skin at the initiation of the disease. A multistep adhesion cascade via different adhesion receptors consisting of 'tethering' and 'rolling' mediated by selectins, alpha-integrins and beta-integrins and the 'arrest' of the cells is initiated during this process. AIMS OF THE STUDY: To evaluate the expression of adhesion molecules and tetraspanins of monocytes of patients with AE and Pso in comparison with healthy controls. METHODS: We analysed the expression of adhesion molecules and tetraspanins on monocytes freshly isolated from the peripheral blood of patients with AE (n = 40) and Pso (n = 65) during exacerbation of their disease in comparison with healthy, non-atopic controls (n = 50). RESULTS: A high number of similarities between monocytes of patients with AE and patients with Pso, and disease-related differences in the expression of CD62L, CD62P, CD11a, CD11b, CD11c, CD49b, CD49d, CD49e and CD18 and the tetraspanins CD9, CD53, CD63 and CD151, which were elevated on monocytes of patients with AE could be observed. CONCLUSION: A distinct expression pattern of adhesion molecules and tetraspanins on monocytes of patients with AE and Pso might influence the recruitment process of inflammatory precursor cells and facilitate new approaches for therapeutic strategies aimed at interrupting the very earliest steps of the fateful recruitment process.     

Decreased expression levels of L-selectin on subsets of leucocytes and increased serum L-selectin in severe psoriasis

L-selectin is a leucocyte adhesion molecule involved in leucocyte interactions with vascular endothelial cells. Following leucocyte activation L-selectin is endoproteolytically released from the cell surface. To assess whether psoriasis vulgaris results in systemic leucocyte activation, we examined expression levels of L-selectin on subsets of peripheral blood leucocytes from patients with psoriasis (n = 25) and normal control subjects. Serum levels of soluble L-selectin were quantified by ELISA in patients with psoriasis (n = 75), pustulosis palmaris et plantaris, and contact dermatitis, as well as normal control subjects. Psoriasis severity was evaluated by psoriasis area and severity index (PASI). L-selectin expression levels on CD4+ T cells, B cells, monocytes, and neutrophils from patients with severe-type psoriasis (PASI > or = 15) was significantly decreased compared with leucocytes from normal control subjects. Furthermore, L-selectin expression on CD4+ T cells showed good inverse correlation with PASI scores. Monocyte L-selectin expression was restored when the skin lesions of psoriasis were remitted. The frequencies of L-selectin+ CD4+ T cells or L-selectin+ CD8+ T cells from patients with psoriasis were almost normal. Serum L-selectin levels in patients with severe-type psoriasis were significantly higher than those in normal control subjects. These results suggest that subsets of leucocytes may be activated in psoriasis, and that L-selectin expression levels on some leucocyte subsets, especially CD4+ T cells, tend to correlate with disease severity of psoriasis.     

Lowered IL-37 gene expression and elevated IL-37-producing tissue-resident immune cells in psoriasis lesional biopsies

Psoriasis is an immune cell-dependent chronic autoimmune skin disorder. Interleukin 37 (IL-37) is a cytokine belonging to the IL-1 family that shows anti-inflammatory and protective effects in various mouse models of psoriasis. Even though various animal models are used to investigate the pathogenic mechanisms of psoriasis, human clinical studies are still needed to make up for the deficiencies, as animal models generally do not exhibit the complex phenotypic features of human psoriasis. Our study aims to demonstrate the relationship between IL-37-producing tissue-resident immune cells with the pathogenesis of psoriasis. The present study was performed on 28 psoriasis patients and 17 healthy volunteers. The ability of anti-inflammatory cytokine IL-37 to impede inflammation and regulate metabolic pathways was assessed by real-time quantitative polymerase chain reaction. Finally, immunofluorescence double staining for CD4⁺IL-37b⁺, CD68⁺IL-37b⁺, and (forkhead box protein P3) Foxp3⁺IL-37b⁺ was performed. The proportion of CD4⁺IL-37b⁺ T cells, CD68⁺IL-37b⁺ macrophages, and Foxp3⁺IL-37b⁺ T regulatory (Treg) cells was significantly increased in the psoriasis group compared to the control group. IL-37 gene expression was downregulated in psoriasis when contrasted to the control group. Our findings disclosed that IL-37-producing tissue-resident immune cells might be involved in the pathogenesis of psoriasis, and thus may be a therapeutic target for individuals with psoriasis.     

Interleukin-18 expression and the response to treatment in patients with psoriasis

Introduction

The aim of the study was to demonstrate Interleukin-18 (IL-18) expression in keratinocytes from psoriatic lesions in comparison to keratinocytes from uninvolved skin and to study the change of expression after therapeutic interventions.

Material and methods

This study included 16 patients of different clinical subtypes of psoriasis. IL-18 gene expression analysis was performed using real-time quantitative PCR. Three biopsies were obtained from each patient. Two were taken from the lesional psoriatic skin and from uninvolved skin before starting treatment. A third lesional skin biopsy was taken at the end of two months'' treatment course. The treatment was in the form of topical steroids or oral systemic methotrexate.

Results

Of all 16 studied patients significantly increased IL-18 expression was noted in keratinocytes from psoriatic lesions before and after treatment when compared to keratinocytes from uninvolved skin (P = 0.001 and 0.002 respectively). The IL-18 expression in the skin lesions after treatment was significantly lower than lesional skin before treatment (P = 0.023). In psoriatic skin lesions of all studied patients IL-18 expression was significantly correlated with disease duration (r = 0.40 and P = 0.01) and clinical severity of psoriasis (r = 0.72 and P = 0.001).

Conclusions

Increased IL-18 expression in keratinocytes from psoriatic lesions of our patients and its correlation with disease duration and severity supported the concept which views psoriasis as a T-cell-mediated autoimmune disease. This could establish therapeutic and preventive approaches for psoriasis that ultimately lead to improved outcomes for patients.     

Interleukin-18 expression and the response to treatment in patients with psoriasis

Introduction

The aim of the study was to demonstrate interleukin-18 (IL-18) expression in keratinocytes from psoriatic lesions in comparison to keratinocytes from uninvolved skin and to study the change of expression after therapeutic interventions.

Material and methods

This study included 16 patients of different clinical subtypes of psoriasis. Interleukin-18 gene expression analysis was performed using real time quantitative PCR. Three biopsies were obtained from each patient. Two were taken from the lesional psoriatic skin and from uninvolved skin before starting treatment. A third lesional skin biopsy was taken at the end of 2 months of treatment. The treatment was in the form of topical steroids or oral systemic methotrexate.

Results

Of all 16 studied patients, significantly increased IL-18 expression was noted in keratinocytes from psoriatic lesions before and after treatment when compared to keratinocytes from uninvolved skin (p = 0.001 and p = 0.002 respectively). The IL-18 expression in the skin lesions after treatment was significantly lower than lesional skin before treatment (p = 0.023). In psoriatic skin lesions of all studied patients IL-18 expression was significantly correlated with disease duration (r = 0.40 and p = 0.01) and clinical severity of psoriasis (r = 0.72 and p = 0.001).

Conclusions

Increased IL-18 expression in keratinocytes from psoriatic lesions of our patients and its correlation with disease duration and severity supported the concept of psoriasis as a T cell mediated autoimmune disease. This could establish therapeutic and preventive approaches for psoriasis that ultimately lead to improved outcomes for patients.     

银屑病患者外周血单个核细胞CCR5的表达及其意义

目的研究银屑病患者外周血单个核细胞趋化因子受体5（CCR5）的表达及其与银屑病皮损面积和严重程度指数（PASI）的关系。方法分离35例中重度寻常型银屑病患者及30例健康对照者外周血单个核细胞（PBMCs）,用RT-PCR法测定PBMCs培养前后CCR5 mRNA的表达水平,免疫荧光标记-流式细胞仪检测CCR5阳性细胞比率。结果治疗前银屑病患者外周血单个核细胞中CCR5 mRNA表达水平明显高于治疗后及健康对照组,并与PASI呈正相关（r=0.516,P〈0.05）。结论 CCR5可能通过活化与趋化单个核细胞到银屑病皮损而参与了银屑病的发病。     

银屑病患者骨髓CD34+细胞RUNX1及其靶基因SLC9A3R1的研究

目的:研究转录调节因子RUNX1及其靶基因SLC9A3R1在银屑病患者骨髓CD34+细胞中的表达及SLC9A3R1与NAT9之间RUNX1的连接位点,以揭示银屑病患者造血干细胞的活性,为深入阐明银屑病患者免疫异常的根源及造血细胞在其中的作用提供理论依据.方法:采用免疫磁珠法分离CD34+细胞,RT-PCR法分别检测RUNX1和SLC9A3R1的mRNA表达,直接测序法检测PCR产物中SLC9A3R1与NAT9之间RUNX1连接位点DNA序列.结果:银屑病患者骨髓CD34+细胞RUNX1表达阳性率低于正常对照组(P＜0.05);银屑病患者骨髓CD34+细胞SLC9A3R1表达水平明显高于正常对照组(P＜0.05),且与PASI评分正相关(r=0.48,P＜0.05);在SLC9A3R1与NAT9之间未发现RUNX1连接位点的突变.结论:决定银屑病患者骨髓CD34+细胞分化的关键基因RUNX1存在异常;银屑病患者骨髓RUNX1和SLC9A3R1可能通过对骨髓造血微环镜和造血干细胞的异常调节参与银屑病的发病.