树突状细胞研究进展

树突状细胞（Dendritic cells,DC)是体内功能最强的一类抗原提呈细胞，参与机体对某一抗原的初次免疫应答过程，还可影响偏向性免疫应答，其功能和表型具有多样性，本文就DC近年来的研究进展做一综述。     

树突状细胞潜在功能的研究进展

1、免疫应答中DC的主要功能 　　DC可以看做是专门将抗原提呈给T细胞的一个细胞体系.它们是最强大的APC,在启动幼龄动物的免疫应答中是必需的.DC由骨髓样或淋巴样的前体演化而来,在许多组织中是微量的,但在体表下(如皮肤、气管、肠管)明显的形成网络,在此捕获抗原,然后迁移到输出淋巴结,提呈加工过的抗原.DC可以通过其特殊的形态和在组织中的定位来鉴别.……     

黄芪多糖对树突状细胞形态和功能影响研究进展

树突状细胞(DC)是目前发现功能最强的一类抗原递呈细胞(APC),因其在机体免疫应答及免疫功能发挥中担当重要角色,成为免疫学研究热点。多糖是中药黄芪的重要有效成分,由己糖醛酸、果糖、阿拉伯糖、半乳糖醛酸等组成,具有免疫调节、抗肿瘤、抗应激和抗氧化等作用。黄芪多糖的免疫调节一直是人们研究的重点,研究发现其可通过促进DC成熟而发挥免疫调节作用。论文从DC的形态和功能变化、DC的成熟和DC表面标志CD80、CD86、CD83和相关细胞因子表达等方面,综合分析了黄芪多糖对DC抗原递呈能力的影响。     

一种抗原递呈细胞--树突状细胞

树突状细胞 ( Dendritic cell,DC)是抗原递呈细胞 ( APC)的一种 ,它可以将抗原物质递呈给 TH细胞。树突状细胞在机体的免疫应答中发挥着重要的作用[2 ] 。最近的研究表明 ,树突状细胞可以递呈肿瘤抗原 ,提高肿瘤病人的免疫能力 [8] 。还有研究表明 ,树突状细胞可以携带 HIV- I,并递呈给抗原反应性 T细胞 ,还可以诱导广泛的淋巴细胞死亡[10 ] 。因此 ,对树突状细胞的研究 ,对基础医学和临床治疗都具有重要意义。树突状细胞的特征是具有树突状外形 ,突起的长度、粗细、数量因不同的树突状细胞而有所不同[1] 。DC起源于骨髓干细胞 ,血液…     

树突状细胞在病毒感染动物免疫应答中的作用

树突状细胞被认为是功能最强的专职抗原提呈细胞。当病毒感染动物体,激活天然免疫信号通路,进而活化树突状细胞。树突状细胞摄取和加工抗原,活化T、B细胞,诱导免疫应答,在调节动物免疫应答中起着重要作用。     

树突状细胞抗肿瘤疫苗研究进展

树突状细胞(DC)是目前发现的抗原递呈功能最强的专职抗原递呈细胞.大量试验证明,DC疫苗在抗肿瘤免疫中发挥着重要的作用.随着分子生物学、免疫学、基因工程技术的发展,各种DC疫苗和DC细胞的治疗应运而生,发展迅速.文章就DC的生物学特性、DC与肿瘤发生与发展的关系、DC抗原的负载方法及其在临床试验中的应用进行了综述.     

新城疫病毒样颗粒对树突状细胞成熟的影响

新城疫病毒样颗粒(NDV VLPs)是由基质蛋白(M)为病毒骨架,装配血凝素-神经氨酸酶和/或融合蛋白等。已有研究表明,NDV VLPs能诱导机体产生特异性体液和细胞免疫应答。然而,关于NDV VLPs如何激活天然免疫应答的研究尚无报道。树突状细胞(DCs)作为专职抗原递呈细胞,在连接天然免疫与适应性免疫之间具有独特功能。本试验以NDV VLPs与小鼠DCs为研究靶点,将NDV VLPs(M+HN)刺激DC以评价DC成熟表征。结果显示该颗粒可被DC有效吞噬并递呈给初始型T细胞,诱导DC表面MHCⅡ和共刺激分子显著上调以及促进DC分泌促炎性细胞因子。另外,还发现不同组装类型的NDV VLPs对诱导DC分泌炎性细胞因子水平不一。结果表明,NDV VLPs可诱导DC成熟,这对更好地理解VLPs激活的天然免疫应答奠定基础,并且为优选NDV VLPs候选株提供参考依据。     

树突状细胞在免疫学上的研究进展

在机体免疫系统中树突状细胞（DC）是目前发现的功能最强的抗原提呈细胞，其功能独特之处在于激活初始型T细胞。近年来，随着DC体外大量培养技术的成熟，有关DC的研究结果日益增多。本从DC分化发育途径和过程，DC在体内分布及成熟迁移，DC对抗原的摄取，加工，提呈的途径及分子机制以及DC与某些重大疾病的关系等诸方面对DC作一综述。     

树突状细胞免疫功能的研究进展

树突状细胞(Dendritic cells,DCs)是因其成熟的细胞具有许多树突样或伪足样突起,被命名为树突状细胞[J].目前,DC是所知体内抗原提呈功能最强的专职抗原提呈细胞(Antigen-presenting cell,APC)[2].近些年,随着对DC分布、发育和功能等方面研究的不断深入,人们发现DCs在免疫系统中具有独特的地位,与其他APC相比,其主要特点是能够刺激初始T细胞活化和增殖,而其他的APC仅能刺激以活化的或记忆性T细胞,因此DC能够促进固有免疫发生和启动获得性免疫.此外,DC还广泛参与肿瘤、感染、自身免疫性疾病的发生和发展,近年来已受到广泛的关注和重视.     

多糖对树突状细胞功能的影响

树突状细胞（dendritic cells,DC）是目前已知机体内功能最强的抗原递呈细胞,也是惟一能启动初始T细胞介导免疫反应的一类细胞。论文综述了多糖对DC功能的影响,多糖能够刺激DC分裂增殖,同时能够显著地诱导DC成熟,能够有效增强DC表面分子表达与增强细胞因子分泌的能力,从而促进DC的抗原递呈能力。     

The role of dendritic cells in shaping the immune response

Dendritic cells are central to the initiation of primary immune responses. They are the only antigen-presenting cell capable of stimulating naive T cells, and hence they are pivotal in the generation of adaptive immunity. Dendritic cells also interact with and influence the response of cells of the innate immune system. The manner in which dendritic cells influence the responses in cells of both the innate and adaptive immune systems has consequences for the bias of the adaptive response that mediates immunity to infection after vaccination or infection. It also provides an opportunity to intervene and to influence the response, allowing ways of developing appropriate vaccination strategies. Mouse and human studies have identified myeloid, lymphoid and plasmacytoid dendritic cells. Studies in domesticated animals with agents of specific infectious diseases have confirmed the applicability of certain of the generic models developed from mice or from in vitro studies on human cells. In vivo and ex vivo studies in cattle have demonstrated the existence of a number of subpopulations of myeloid dendritic cells. These cells differ in their ability to stimulate T cells and in the cytokines that they produce, observations clearly having important implications for the bias of the T-cell response. Dendritic cells also interact with the innate immune system, inducing responses that potentially bias the subsequent adaptive response.     

Maturation of bovine dendritic cells by lipopeptides

The response of DC, and the subsequent stimulation of T cells, is an essential part of the initiation of immune responses following microbial challenge. The response of human DC to bacterial lipopeptides is mediated by toll-like receptor 2, and is characterised by DC maturation and the enhanced capacity to stimulate of T cells. We report here that bovine DC are also induced to mature following lipopeptide stimulation. Exposure of DC to the model lipopeptide Pam3CSK4 was associated with increased expression of MHC, costimulatory molecules, and enhanced secretion of IL-12 and TNFalpha. Lipopeptide-matured DC were superior in their ability to induce T cell activation and IFNgamma secretion. In contrast, exposure of MPhi to lipopeptides induced down-regulation of MHC expression and much lower increases in IL-12 secretion. A lipopeptide derived from the sequence of a relevant mycobacterial lipoprotein, MPB83, also influenced bovine DC by stimulating increases in IL-12 and TNFalpha secretion. These different changes in bovine DC and MPhi may have important implications for immune responses induced following bacterial infection with uptake of microbes by DC resulting in potentiation of their immunostimulatory capacity and uptake by MPhi having a much less marked effect on immune responses.     

CD205-positive,Sepharose-induced peritoneal exudate cells: a new resource for DC research in the chicken

Veterinary Research Communications - Dendritic cells (DC) are important antigen-presenting cells and are among the least characterized immune cells in the chicken. In order to obtain chicken DC,...     

Characterization of conventional and plasmacytoid dendritic cells in swine secondary lymphoid organs and blood

Dendritic cells (DCs) act as antigen presenting cells that bridge innate and adaptive immune systems with the unique capacity to initiate primary T-cell responses and efficiently stimulate memory responses. In pig, little information is available about these cells in secondary lymphoid organs, the place where T cell activation usually occurs. As increased knowledge on DC is a necessary prerequisite to further understand their role in response to microbial infection or in protection after vaccination, we investigated the DC types that would be present in tonsil, spleen and non-subcutaneous lymph nodes in the steady state. One population was composed of CD172a(+)CD11R1(+)CD1(+/-)CD80/86(+/-) cells and would correspond to conventional DCs (cDC), while the other one was composed of CD172a(+)CD4(+)CD1(+/-)CD80/86(+/-) cells and would correspond to plasmacytoid DCs (pDC). These subsets were also detected in blood but spleen was the tissue with the higher frequency of such DCs. In lymphoid organs, most of cDC and pDC were in an immature status, as revealed by the low percentage of cells expressing the co-stimulatory molecule CD80/86. However, expression of that marker by 5% of DCs in organs and up to 15% in blood, together with lower expression of CD1a and expression of CD208, would indicate a partial activation and/or semi-maturation. Interestingly, 8% of tonsil pDC and 15% of blood pDC were shown to secrete IFN-alpha, while 18-20% of cDC expressed TNF-alpha in these tissues. Both cell types also expressed IL-12 and IL-10 in the steady state. Measurements of IFN-alpha, TNF-alpha, IL-12 and IL-10 levels in serum confirmed their production within immune homeostasis, whereas IL-6, IL-18 and IFN-gamma could not be detected. Altogether, these data complete knowledge on porcine immune system cells and will be a useful tool for further in vivo studies on porcine DC role in peripheral tolerance induction and in immune responses to pathogens.     

BCG vaccination of neonatal calves: potential roles for innate immune cells in the induction of protective immunity

Bovine tuberculosis is a disease of increasing incidence in the UK causing major economic losses and with significant impact on bovine and, potentially human health: the causative agent Mycobacterium bovis is a zoonotic pathogen. Neonatal vaccination with the attenuated M. bovis Bacille Calmette Guerin (BCG) vaccine confers a significant degree of protection in cattle, and is a widely used control strategy for human TB. The adaptive immune system is relatively immature in neonates and increased numbers of innate effector cells present in young animals and human infants may compensate for this, enabling effective immune responses to vaccination. Natural killer cells and subsets of γδ TCR+ T lymphocytes secrete high levels of interferon gamma and can interact with antigen presenting cells to promote both innate and adaptive immune responses. These cell populations may be pivotal in determining immune bias following neonatal vaccination with BCG.     

Dendritic cells: a specialized complex system of antigen presenting cells

The dendritic cell (DC) network is a specialized system for presenting antigen to naive or quiescent T cells, and consequently plays a central role in the induction of T cell and B cell immunity in vivo. Despite considerable achievements in the last ten years, in our understanding of how DC induce and regulate immune responses, much remains to be learned about this complex system of cells. The history and current status of DC termed "directors of the immune system orchestra" is reviewed. The present understanding of DC cell biology, function and use, taking into account their complexity is discussed.