自身免疫病与树突状细胞免疫调控

树突状细胞（dendriti cells，DCs）是已知功能最强的专职抗原提呈细胞（professional antigen-presenting cells，APC）。DCs活化静止性T细胞的效率是其他APC（如巨噬细胞等）的1000倍。同时，作为APC，它能惟一激活初始型T细胞（naive T cells）致敏，产生初次免疫应答。成熟DCs联合抗原作用可加强免疫应答，而不成熟DCs又可诱导抗原特异性T细胞克隆清除（无能）或产生调节T细胞（Tr），产生免疫抑制或免疫耐受。因此，DCs被视为重要的免疫调节工具。有望应用于自身免疫病、慢性病毒感染和肿瘤等一系列疾病的临床治疗。本文就DCs免疫凋控与自身免疫病关系综述如下。     

树突状细胞在棘球蚴感染所致免疫耐受中作用的研究进展

树突状细胞（dendritic cells，DCs）是一种抗原提呈细胞（antigen⁃presenting cells，APC），是免疫应答和免疫耐受的重要调节者，在机体固有免疫和适应性免疫中发挥关键作用。既往研究表明，棘球蚴在宿主体内长期寄生的原因与DCs诱导机体免疫耐受密切相关。本文旨在总结DCs在棘球蚴感染导致的免疫耐受中作用的研究进展，以期为棘球蚴感染防治及棘球蚴病免疫治疗提供理论基础和研究思路。     

树突状细胞在慢性阻塞性肺疾病发病过程中的作用

树突状细胞（dendrtic cells,DCs）是目前发现的体内功能最强的抗原递呈细胞（antigen presenting cells,APC）,在免疫应答中有着的独特的地位。越来越多的证据表明,呼吸道DCs不仅能诱导外界吸人抗原致敏,而且还能显著刺激初始型T细胞向Thl或Th2分化,而且在调节T细胞免疫应答、     

慢性阻塞性肺疾病与树突细胞亚群的相互关系

树突细胞是1973年由美国Steinman首先发现,是目前所知的抗原提呈功能最强的抗原提呈细胞（autigen pnesenfing cell,APC）,对树突细胞（dendritic cells,DCs）的研究有助于深入了解机体免疫应答的产生和调控机制,对肿瘤、移植排斥、感染等发生发展机制的认识有重要理论意义,     

抗原呈递细胞分泌的细胞因子与自身免疫性疾病

组织特异性自身免疫性疾病，包括多发性硬化症（MS）、类风湿性关节炎（RA）等，都是由于周围淋巴器官对自身抗原的耐受消失，导致自身反应性的效应细胞过度扩增，引起组织特异性炎症所致。虽然辅助性T细胞（Th）广泛参与了自身免疫性疾病的发生，但抗原呈递细胞（APC）才是自身免疫反应起始和恶化的最关键因素。APC在外周免疫中发挥多重作用，     

以树突状细胞为基础的肝癌免疫治疗研究进展

近二十年来通过对树突状细胞（dendritic cells，DC）的研究，学者们一致认为DC是目前发现的功能最强的抗原提呈细胞（antigen presenting cell，APC），其具有树枝状形态，膜表面高表达MHCⅠ和Ⅱ类分子以及多种辅助分子（如CD54、CD80、CD86等），能有效摄取、加工和处理抗原并激活初始型T细胞。DC是启动、调控、并维持免疫应答的中心环节。原发性肝癌（HCC）是高度恶性肿瘤之一，对放化疗均不敏感，现行治疗方法是以手术为主的综合治疗，但肿瘤切除后复发率较高。随着分子生物学、细胞生物学和人类基因组学等学科的发展，基因免疫治疗可望成为肝癌的有效治疗手段，其中以DC为基础的肝癌免疫治疗日益受到重视，取得了初步成果。本文就此方面进展进行综述。     

树突状细胞与肝脏疾病

免疫反应的产生首先是由抗原提呈细胞(antigenpresenting cells,APC)捕获抗原,经其加工处理后将抗原信息传递给T,B淋巴细胞,从而引发一系列的特异性免疫应答.APC包括树突状细胞(dendritic cells,DC)、巨噬细胞(MΦ)、B细胞等,其中DC是人体内最具潜能的抗原提呈细胞(APC),能在体内外直接激活纯真(naive)T细胞,提呈抗原给MHC-Ⅰ类限制性CD8+和MHC-Ⅱ类限制性CD4+T淋巴细胞,诱导特异性免疫应答[1-6].     

慢性乙型肝炎患者树突状细胞特点及其免疫治疗

树突状细胞（DC）是诱导和维持抗原特异性免疫应答非常重要的抗原提呈细胞（APC），研究表明慢性乙型肝炎（CHB）患者体内DC功能下降，这可能是导致CHB的重要原因之一。DC增强免疫疗法的基本原理是提高CHB患者体内DC功能，诱导强烈的HBV特异性免疫反应清除病毒。     

体外培养急性白血病树突细胞的培养基选择

急性白血病（AL）通过造血干细胞移植可望治愈,但是受患者年龄和供者来源的限制,不能得到广泛开展,因而AL化疗完全缓解后体内微小残留病灶的清除成为当今AL治疗的一大热点。树突状细胞（DC）是已知的机体内功能最强的抗原提呈细胞（APC）,也是惟一能直接激活初始型T细胞的APC,进而启动和调控机体免疫应答,起到清除AL残留细胞的目的。另外,DC还可作为效应细胞直接杀伤白血病细胞。     

树突细胞与乙型肝炎病毒感染

树突状细胞(Dendritic Cells,DC)由美国学者Steinman及cohn于1973年发现,是体内重要的一类抗原递呈细胞(Antigen—presenting cells,APC),其共同的生物学特性是细胞表面有许多树枝状突起,胞内具有丰富的线粒体,与巨噬细胞、B细胞抗原递呈功能不同,只有DC能够刺激初始型T细胞(Naive T cells)使之分化、激活,后者影响机体的细胞和体液免疫系统,因此,DC被认为是机体免疫反应的始动者。     

大鼠胰腺导管来源干细胞向胰岛素分泌细胞分化的体外培养

目的:研究在体外条件下从大鼠胰腺导管分离的干细胞向胰岛素分泌细胞分化的产物细胞的形态、表型及功能.方法:采用胶原酶原位消化法消化大鼠胰腺,差异贴壁法培养出胰腺导管来源千细胞(PDSCs),对其进行形态学与表型鉴定.采用无血清培养基,添加Matrigel、exendin-4诱导干细胞向胰岛素分泌细胞分化,鉴定产物细胞的形...     

胚胎干细胞向心肌细胞分化中内皮细胞的作用

目的:研究胚胎干细胞向心肌细胞分化过程中,内皮细胞与心肌细胞之间的功能性联系. 方法:通过检测CGR8-GFP小鼠胚胎干细胞系心肌α-肌球蛋白重链(α-MHC)荧光蛋白表达情况变化,观察抑制内源性内皮细胞、添加外源性内皮细胞以及两者并存情况下,胚胎干细胞分化所得心肌细胞数量的变化. 结果:(1)在胚胎干细胞分化过程中,加入外源性内皮细胞后,心肌细胞形成明显增多.(2)特异性抑制内源性内皮细胞,心肌细胞形成明显减少.(3)外源性内皮细胞与胚胎干细胞共培养能够部分挽救由于内源性内皮细胞抑制所导致的心肌细胞形成障碍. 结论:在胚胎干细胞分化过程中,内源性内皮细胞对于促进心肌细胞形成起着至关重要的作用,是形成心肌细胞发育微环境的关键因子.在胚胎干细胞向心肌细胞分化过程中,外源性内皮细胞可以刺激心肌细胞形成,从而得到大量心肌细胞,具有潜在的临床应用价值.     

侧群细胞与肝癌干细胞

肝癌是严重威胁人类生命和健康的一种疾病.其病因和发病机制尚不完全清楚,治疗缺少有效靶点.对肝癌恶性生长、转移及复发机制的研究正在逐渐深入.近年来的研究认为,肿瘤中存在一小群具有自我更新和分化潜能的细胞,即肿瘤干细胞,可能是肿瘤转移和复发的根源.肝癌中应同样存在这样的一群细胞.侧群(side population,SP)细胞是肿瘤细胞中一小部分,具备干细胞的多种特性且易于分离.肝癌组织中SP细胞的鉴定和分离有可能找到肝癌干细胞,有助于肝癌的转移和复发机制的研究,并为肝癌治疗提供有效治疗靶点.     

Hepatoma cells up-regulate expression of programmed cell death-1 on T cells

AIM： To investigate the effect of hepatoma cells on up-regulation of programmed cell death-1 （PD-1）, and the function of PD-1 on T cells. METHODS： HepG2 or HepG2.2.1.5 cells were cocultured with a lymphoma cell line-Jurkat cells. PD-1 expression was detected by flow cytometry. IL：2, INF-γ and IL-10 in culture supernatant were detected by enzyme-linked immunosorbent assay （ELISA）. Cytotoxic action of T cells was determined by MIF reduction assay-direct mononuclear cell cytotoxicity assay. RESULTS： The PD-1 expression on Jurkat cells increased by 16.17% ± 2.5% and 17.43% ± 2.2% after HepG2 or HepG2.2.1.5 cells were co-cultured for 48 h. The levels of IL-2, INF-γ and IL-10 in the culture supernatant were 202.9 ＋ 53.0 pg/mL, 88.6 ± 4.6 pg/mL and 63.7± 13.4 pg/mL respectively, which were significantly higher than those （102.9 ± 53 pg/mL, 39.3 ± 4.2 pg/mL, and 34.6 =E13.7 pg/mL） in the control group （P 〈 0.05）. The OD value for MTT assay in the blocking group （0.29 ± 0.06） was significantly higher than that （0.19 ± 0.09） in the control group （P 〈 0.05）. CONCLUSION： PD-1 expression on Jurkat cells is upregulated by hepatoma cells, cytokines and cytotoxic action are elevated after PD-1/PD-L1 is blocked.     

Identification of cells in culture.

Most laboratories using cells cultured in vitro maintain multiple cell lines. Such lines should be monitored for species and intraspecies characteristics to prevent invalidation of research work due to incidents of cell line cross-contamination. This report describes the results obtained when 246 cell cultures were examined for evidence of cross-contamination or mislabeling. Using species-specific antigens, isoenzyme electrophoresis, and chromosomes as markers of identity, 14% of the cultures submitted were found to be contaminated by cells of another species. Of human cell lines submitted 25% were of HeLa cell origin, as determined by 2 intraspecies markers, glucose-6-phosphate dehydrogenase and chromosome analyses. The fact that, overall, nearly 30% of the cell lines examined were incorrectly designated makes the importance of cell line monitoring self-evident.     

Robust measurement of telomere length in single cells

Measurement of telomere length currently requires a large population of cells, which masks telomere length heterogeneity in single cells, or requires FISH in metaphase arrested cells, posing technical challenges. A practical method for measuring telomere length in single cells has been lacking. We established a simple and robust approach for single-cell telomere length measurement (SCT-pqPCR). We first optimized a multiplex preamplification specific for telomeres and reference genes from individual cells, such that the amplicon provides a consistent ratio (T/R) of telomeres (T) to the reference genes (R) by quantitative PCR (qPCR). The average T/R ratio of multiple single cells corresponded closely to that of a given cell population measured by regular qPCR, and correlated with those of telomere restriction fragments (TRF) and quantitative FISH measurements. Furthermore, SCT-pqPCR detected the telomere length for quiescent cells that are inaccessible by quantitative FISH. The reliability of SCT-pqPCR also was confirmed using sister cells from two cell embryos. Telomere length heterogeneity was identified by SCT-pqPCR among cells of various human and mouse cell types. We found that the T/R values of human fibroblasts at later passages and from old donors were lower and more heterogeneous than those of early passages and from young donors, that cancer cell lines show heterogeneous telomere lengths, that human oocytes and polar bodies have nearly identical telomere lengths, and that the telomere lengths progressively increase from the zygote, two-cell to four-cell embryo. This method will facilitate understanding of telomere heterogeneity and its role in tumorigenesis, aging, and associated diseases.Telomeres are the ribonucleoprotein structures that cap and protect linear chromosome ends from genomic instability and tumorigenesis (1, 2). Intriguingly, telomere shortening protects against tumorigenesis by limiting cell growth (3, 4), but also can impair tissue regenerative capability and cell viability (5, 6).Thus far, most assays of telomere length measure average telomere length from aggregates of many cells derived from dissected tissues, cultured cells, or blood (7). Telomere restriction fragment (TRF) determination (1, 8), a Southern blot-based technique, remains the “gold standard” for determining absolute telomere length, but requires a large amount of starting material (0.5–5 µg DNA) and several days for processing. Moreover, the requirements for gel electrophoresis and hybridization limit the scalability of this assay. Recently, a quantitative PCR (qPCR)-based method for telomere length measurement was developed, providing the convenience and scalability of PCR (9). Although the DNA requirement (35 ng) for qPCR is significantly less than TRF, it still relies on populations of cells to derive sufficient amount of DNA.Quantitative FISH (Q-FISH) allows sensitive visualization of relative telomere length from individual cells and individual telomeres, but this method requires many cells or metaphase arrested cells, which precludes its application to many sample types, including postmitotic cells, senescent cells, and other nondividing cells, and when only one actual cell is required to test. In addition, preparing chromosome spreads requires significant technical skill, and only proliferating cells within a population reach metaphase stage, so this analysis potentially biases the estimates of telomere length for a given cell population (10–12). High-throughput Q-FISH, flow FISH, and single telomere length analysis can be used for telomere measurement of dividing, nondividing, and senescent cells, but these methods also require large cell populations (13–15).The ability to measure telomere length in single cells rather than relying upon average telomere length in cell populations or the entire tissue enables the study of biological heterogeneity on a cell-by-cell basis, an issue of fundamental importance for studies of aging, development, carcinogenesis, and many other diseases. Here, we demonstrate an accurate determination of telomere length in individual cells, with the resolution and scalability of the qPCR telomere length assay.The basis of qPCR is that within a given cell, the ratio of the copy number of telomere repeats to the copy number of a multicopy reference gene is fixed (3), and this method, because of its simplicity, has been widely used to investigate a variety of telomere shortening-associated diseases (7), even sensitive enough to identify mild telomere dysfunction resulting from chronological life stress (16, 17). We adapted qPCR to measure telomere length in individual cells by using a preamplification step that specifically targets both the telomere and multicopy genes, followed by a qPCR assay to obtain telomere to reference gene (T/R) ratio. A single-cell telomere (SCT) length measurement method (SCT-pqPCR) runs robustly, and shows an identical T/R ratio for two sister blastomeres from two-cell–stage mouse embryos. The average result from SCT-qPCR with multiple single cells is linearly correlated to Q-FISH, TRF, and conventional qPCR assays designed for a large number of cells. The heterogeneity of telomere length among several populations of cells by SCT-pqPCR run on multiple single cells is consistent with—and sometimes superior to—results obtained by Q-FISH. Application of SCT-pqPCR to study telomere length during early embryo development, aging, and cancer demonstrate the value of this single-cell telomere length assay method.     

对链脲佐菌素诱导的糖尿病大鼠壁细胞和G细胞的体视学研究

采用ＨＥ染色和免疫组化方法结合生物体视学技术，对链脲佐菌素诱导的糖尿病大鼠在胃底腺的壁细胞和幽门部胃粘膜的Ｇ细胞进行立体计量研究。结果显示：糖尿病状态的早期，壁细胞和Ｇ细胞的体积均明显增大，数量却显著减少。根据正常情况下壁细胞和Ｇ细胞的细胞动力学变化、胃泌素的生物学作用和上述实验结果，认为大鼠胃底腺峡部的干细胞向壁细胞分化成熟的功能及Ｇ细胞的分裂增殖活动，在胰岛素缺乏的情况下受到一定程度的抑制，而这种功能的抑制是糖尿病状态下易出现胃粘膜萎缩、胃酸分泌减少和胃轻瘫的重要原因之一。     

肺干细胞研究进展

干细胞研究是现代医学领域研究热点之一.肺部疾病所导致的不同程度呼吸系统病理改变和功能受损,都伴随着肺组织的修复和重塑过程.对于肺部疾病的干细胞研究和应用尚有许多问题有待进一步的明确和探索.肺干细胞包括了肺组织自身的干细胞修复和肺外组织来源的干细胞修复.肺组织内的干细胞包括肺内上皮性干细胞、肺问充质干细胞、肺侧群细胞;其中肺内上皮性干细胞又包括了基底细胞、Clara细胞、Ⅱ型肺泡上皮细胞、"芽孢"样细胞.肺外组织来源的干细胞修复包括骨髓间充质干细胞和造血干细胞.干细胞治疗方法在临床上有巨大的应用前景.     

Evidence of direct interaction between Kupffer cells and colon cancer cells: an ultrastructural study of the co-culture

Abstract: A co-culture study of purified rat Kupffer cells and human colon cancer cells was performed, and the process of the tumor cell injury was observed under an inverted type fluorescence microscope loaded with propidium iodide, and also under an electron microscope. Ultrastructurally there was direct membrane-to-membrane interaction between Kupffer cells and colon cancer cells in time. The interaction occurred 1 h after start of the co-culture, and injured tumor cells were observed closely attached to pseudopodia of Kupffer cells at 6 h. The number of propidium iodide-positive tumor cells with damage increased in time. Pretreatment with N^G-monomethyl-L-arginine reduced the number of injured tumor cells without preventing morphological interactions, but superoxide dismutase did not prevent the tumoricidal effect. Pretreatment with trypsin completely inhibited cell interaction and damage to tumor cells. In conclusion, the morphological interaction of Kupffer cells as a first step and the involvement of nitric oxide-derived free radicals as a second step seem to play a significant role in the host-defense mechanism.     

Deformability characteristics of sickle cells by microelastimetry

Deformability of normal and sickle erythrocytes was measured by means of micropipette elastimetry with determination of intrinsic membrane rigidity (P) and total cell deformability (Pt). In the elastimetric technique employed, negative pressure at the pipette tip was generated and measured continuously. Membrane rigidity is defined as the negative pressure, in mm H₂O, required to induce a hemispherical projection of the cell surface into the micropipette, and total cell deformability as the negative pressure required to aspirate the entire cell into the pipette lumen. Membrane rigidity for oxygenated sickle discocytes was not statistically different from that of control normal discocytes, but Pt measurements were significantly higher for sickle than normal discocytes. Irreversibly sickled cells (ISCs) had markedly increased membrane rigidity and whole cell deformability when compared to control normal cells. Mildly deformed ISCs and severely deformed ISCs at ambient pO₂, both showed significantly higher mean membrane rigidity values than sickle discocytes and reversibly sickled cells. Sickle and normal discocytes both showed membrane elasticity with reversion to original cell shape following release of the cell from its aspirated position at the pipette tip. ISCs, however, exhibited elastic deformation of the membrane. These studies provide further evidence of progressive alteration of the sickle cell membrane induced by the sickling-unsickling process, culminating in formation of the ISC, and suggest a role for the ISC membrane abnormality in the pathologic rheology of sickle cell disease.