Therapeutic treatment of experimental colitis with regulatory dendritic cells generated with vasoactive intestinal peptide

BACKGROUND & AIMS: Crohn's disease is a chronic debilitating disease characterized by severe T helper cell (Th)1-driven inflammation of the colon partially caused by a loss of immune tolerance against mucosal antigens. The use of regulatory dendritic cells (DCs) with the capacity to induce regulatory T cells has been proposed recently for the treatment of Crohn's disease in a strategy to restore immune tolerance. Vasoactive intestinal peptide is an immunomodulatory neuropeptide that induces regulatory DCs. The aim of this study was to investigate the therapeutic effect of vasoactive intestinal peptide-induced regulatory DCs (DC(VIP)) in a murine model of colitis. METHODS: We examined the therapeutic action of DC(VIP) in the colitis induced by intracolonic administration of trinitrobenzene sulfonic acid, evaluating diverse clinical signs of the disease including weight loss, diarrhea, colitis, and histopathology. We also investigated the mechanisms involved in the potential therapeutic effect of DC(VIP), such as inflammatory cytokines and chemokines, Th1-type response, and the generation of regulatory T cells. RESULTS: DC(VIP) injection significantly ameliorated the clinical and histopathologic severity of colitis, abrogating body weight loss, diarrhea, and inflammation, and increasing survival. The therapeutic effect was associated with down-regulation of both inflammatory and Th1-driven autoimmune response, by regulating a wide spectrum of inflammatory mediators directly through activated macrophages, and by generating interleukin-10-secreting regulatory T cells with suppressive capacity on autoreactive T cells. CONCLUSIONS: The possibility to generate/expand ex vivo regulatory DC(VIP) opens new therapeutic perspectives for the treatment of Crohn's disease in human beings, and may minimize the dependence on nonspecific immunosuppressive drugs used currently for autoimmune disorders.     

Th/Tr淋巴细胞比值评估乳腺癌患者抗肿瘤免疫状态

目的:探讨用Th/Tr淋巴细胞比值评估乳腺癌患者的抗肿瘤免疫状态.方法:采用流式细胞术检测53例不同分期的乳腺癌患者化疗前外周血中CD4+Th细胞、CD4+CD25+Tr细胞水平,计算Th/Tr比值,并与30例健康志愿者进行比较.结果:有转移与无转移的乳腺癌患者Tr细胞绝对值差异无统计学意义(103±75 vs 109±70,P=0.722).有转移的乳腺癌患者Th/Tr淋巴细胞比值小于无转移者(3.83±1.37 vs 6.11±2.93,P<0.001),无转移患者小于健康志愿者(6.11±2.93 vs 11.24±1.84,P<0.001).结论:Th/Tr比值对乳腺癌患者抗肿瘤免疫状态的评估优于Tr细胞计数,Th/Tr比值在乳腺癌患者尤其是有转移的乳腺癌患者中显著降低,其水平变化可作为评估乳腺癌患者免疫状态的有效指标.     

Riemekasten Regulatorische T-Zellen – ein mögliches Ziel zur Behandlung von systemischen Autoimmunerkrankungen

Zusammenfassung. Regulatorischen T-Zellen kommt eine Schlüsselrolle bei der Aufrechterhaltung der Immuntoleranz zu und ihr Einsatz könnte eine entscheidende Rolle in unserem therapeutischen Repertoire einnehmen. Die vorliegende Arbeit soll einen Überblick über den aktuellen Stand der Forschung über regulatorische T-Zellen geben. Ein Teil dieser Zellen entsteht im Rahmen der normalen T-Zellreifung im Thymus, andere Subtypen können in der Peripherie induziert werden. Regulatorische T-Zellen zeichnen sich durch folgende Besonderheiten aus: Sie proliferieren kaum, hemmen die Aktivierung anderer T-Zellen und sind protektiv gegen Autoimmunerkrankungen. Die zugrundeliegenden Wirkungsmechanismen sind noch nicht vollständig aufgeklärt, wahrscheinlich spielen Zell-Zell-Kontakt-abhängige Mechanismen und Zytokine wie IL-10 und TGF eine Rolle. Zur Identifizierung von regulatorischen T-Zellen sind neben CD25 noch andere Oberflächenmarker bekannt, allerdings ist bisher kein Markermolekül bekannt, das ausschließlich bei regulatorischen T-Zellen nachweisbar ist. Abschließend wird ein Ausblick über mögliche therapeutische Anwendung dieser Zellen gegeben.     

Genetic basis of inherited peripheral neuropathies

Progress in the elucidation of the genetic basis for inherited peripheral neuropathies has been remarkable over the last years. In particular, the molecular mechanisms underlying the autosomal dominantly inherited disorders Charcot–Marie–Tooth disease type 1A (CMT1 A), Charcot–Marie–Tooth disease type 1B (CMT1B), and hereditary neuropathy with liability to pressure palsies (HNPP) have been determined. While mutation in the gene encoding the major myelin protein, P_o has been associated with CMT1B, CMT1A and HNPP have been shown to be associated with reciprocal recombination events leading either to a large submicroscopic duplication in CMT1 A, or the corresponding DNA deletion in HNPP. Available evidence is consistent with the hypothesis that one or more genes within the relevant rearranged segment of 1.5 Mb on chromosome 17 is sensitive to gene dosage providing a novel mechanism for inherited human disorders. It is likely that the gene encoding the peripheral myelin protein PMP22 is at least one of the genes involved since the PMP22 gene maps within the CMT1A duplication (or HNPP deletion), and point mutations within it have been shown to cause a CMT phenotype in humans and comparable neuropathies in rodents (trembler and trembler^J). The mechanism(s) by which gene dosage and point mutations affecting the same gene might lead to a similar phenotype are currently unknown but recent transgenic mouse experiments suggest that similar mechanisms may also underlie other genetic diseases. © 1994 Wiley-Liss, Inc.     

TGF-β

A balance between an adequate immune response to an antigen or pathogen and tolerance is a prerequisite for normal immune homeostasis and the well-being of the host. In this complex self-regulation multiple mechanisms have been implicated as contributing to the immune tolerance network, including apoptosis, anergy, and active suppression. Current excitement focuses on active suppression and new regulatory T cell-mediated pathways of immunosuppression that are being unraveled. Central to several of these pathways is transforming growth factor-β (TGF-β), a potent immunoregulatory cytokine that contributes to the function and generation of regulatory T cells.     

移植免疫耐受中调节性T细胞的研究进展

调节性T细胞（Tr）在诱导和维持移植免疫耐受过程中的作用越来越受到人们的重视。根据不同的细胞表型和功能已将Tr分为若干亚类，首先是胸腺内T细胞发育过程中自然产生的CD4^＋T细胞亚群，能够构成性表达IL-2受体的仅链（CD25）存在于外周，体内体外均可抑制效应性T细胞的增殖和功能；其次是产生于正常的免疫应答过程中的诱导性Tr亚群，包括Tr1和Th3通过分泌细胞因子如IL-10和TGF—β发挥抑制作用。除此之外，也有报道CD8^＋Tr、双阴性T（DNT）细胞和NKT细胞在移植耐受的不同模型中亦发挥重要作用。因而研究各种Tr亚群的生物学特征、调节机制及其在移植耐受中的作用非常必要。     

褪黑素对哮喘大鼠CD4^＋CD25^＋调节性T细胞的影响及抗炎作用

目的:研究褪黑素对哮喘大鼠CD4 CD25 调节性T细胞的影响及抗炎作用。方法:32只SPF级SD大鼠随机分成4组造模,哮喘组、MT组、地塞米松组、正常组,每组8只。各组于最后一次雾化激发后取外周血涂片染色,计数外周血中嗜酸性粒细胞(EOS)百分比;收集肺泡灌洗液(BALF),计数炎症细胞总数;制作肺组织石蜡切片,HE染色计数气道周围EOS数目;用免疫增强浊度法检测血清中IgE水平;用流式细胞术检测外周血中CD4 CD25 Tr数目变化。结果:①哮喘组外周血中CD4 CD25 Tr/CD4 T细胞比值与气道周围EOS细胞数呈现高度负相关(r=-0.73,P<0.05),与BALF细胞总数亦高度负相关(r=-0.78,P<0.05),与血清IgE水平未见显著相关;②CD4 CD25 Tr/CD4 T细胞比值哮喘组显著高于其他各组(均为P<0.01),其他三组差异无统计学意义;③MT组气道周围EOS计数、外周血EOS比例、BALF细胞总数及IgE水平明显低于哮喘组(均为P<0.01)。结论:CD4 CD25 Tr参与了哮喘的发病。褪黑素能显著降低哮喘大鼠CD4 CD25 Tr的数目,有效减轻哮喘大鼠气道炎症和血清IgE上升水平。     

一种用流式细胞术检测基因转移效率的新方法

背景与目的：基因转移效率一直以来都是用表达报告基因的细胞（显色或发荧光）占细胞总数的百分比（即转染率）来表达,此百分比是由研究者借助显微镜（或荧光显微镜）计数得出来的。该方法（本文称为人工计数法）存在客观性、准确性不够和工作量大、且不能同时检测基因表达效率等问题。本研究拟寻找一种客观、准确、简便地检测基因转移和表达效率的新方法。方法：以绿色荧光蛋白（GFP）基因为目的基因、重组腺病毒（AdCMV/GFP)为基因载体,用人工计数法测定其对肝癌细胞株HepG2的转染率;用流式细胞术（flow cytometry,FCM)测定其对肝癌细胞株HepG2、Bel7402、Hep3B、SMMC7721和鼻咽癌细胞株CNE－2的转染效率和GFP（绿色荧光蛋白）基因的表达效率（以荧光指数表示）。结果：以FCM测得AdCMV/GFP对HepG2的转染率与载体量呈对数相关（与人工法相似,但前者略高）,荧光指数与载体量呈线性相关（γ＝0．9984）,其它细胞株的结果与HepG2相似。结论：采用FCM法测定基因转移效率克服了主观因素的影响,测定结果客观准确,可以用于测定基因载体对真核细胞的转染效率,或研究转录调控元件的功能。     

Die ableitenden Tränenwege des Menschen Morphologische und biochemische Untersuchungen

Purpose. Infections occur frequently in the region of the efferent tear ducts. Exact knowledge of the anatomical structure and of cellular defense mechanisms is necessary to understand the pathological processes. This sudy analyzed the efferent tear ducts with regard to physiological function and possible defense mechanism against infections. Materials and methods. We used histological, immunohistochemical and electron-microscopic techniques to investigate the lacrimal systems from 31 body doners aged 54–88 years. Results. The efferent tear ducts are lined by a double-layered epithelium resting on a broad basement membrane. These cells contain many lipid droplets and secretory vacuoles in their apical part. Inside the epithelium cells are arranged partly in cell groups forming mucous glands, which morphologically resemble goblet cells of the tarsus palpebrae. The secretory products of these cells contain various carbohydrates including sialic acid. Lymphocytes and macrophages are found in the submucosa partly penetrating the epithelium. Conclusions. Lipids and mucins of epithelial and goblet cells form a specialized protective layer on the epithelium of the tear ducts which enables easy drainage of tear fluid into the inferior meatus of the nose. Together with immunocompetent cells the protective layer prevents invasion of pathogenetic agents.