登革病毒对人血管内皮细胞感染性的研究

用登革病毒Ⅱ型（DV2）感染体外培养和传代的人脐静脉内皮细胞（HUVEC）,研究发现,HUVEC是登革病毒的允许性细胞。病毒感染后12h即可在培养上清中用微量蚀斑法测出病毒,病毒滴度48h达高峰,以后迅速下降。并发现在一定范围内病毒产量随病毒感染复数（MOI）的增加而增高。间接免疫荧光法证明感染的HUVEC胞浆及胞膜上携带DV2抗原。电镜和光镜下,感染细胞未见明显的形态和结构改变。     

人外周血树突状细胞的形态学研究

血树突状细胞是一种重要的免疫辅助细胞,可以从外周血分离获得。本研究对自人外周血分离的树突状细胞进行了免疫细胞化学、透射电镜和扫描电镜观察。结果表明,血树突状细胞呈Ｓ—１００蛋白阳性反应,ｌｙｓｏｚｙｍｅ阴性反应。细胞形态不规则,有长短、粗细不等的突起,核不规则且多扭曲。体外培养时,血树突状细胞可互相接触,或数个聚集成群或与淋巴细胞形成花环。实验中发现Ｓ—１００蛋白阳性的血树突状细胞有两种不同的形态类型。文中除对血树突状细胞的生理功能进行了讨论外,还提出了这两类细胞很可能是外周血树突状细胞的前体细胞和成熟的树突状细胞。     

人外周血树突状细胞亚型的形态学观察

Ｓ１００ 蛋白染色是鉴定树突状细胞（ＤＣ） 的一种重要而可靠的方法。本文采用Ｓ１００ 蛋白免疫细胞化学方法及电镜观察, 对人外周血树突状细胞的亚型进行研究。结果表明： 人血ＤＣ在形态学上分为两个亚型－ Ⅰ型中等淋巴细胞大小, 线粒体少, 核内异染色质多; Ⅱ型胞体较大, 线粒体丰富, 异染色质少     

人外周血树突状细胞体外诱导扩增的研究

目的:探讨可用于临床治疗功能成熟的DC体外扩增的优化培养方案。方法:胎牛血清培养基联合细胞因子rhGM-CSF(100ng/mL)和rhIL-4(50 ng/mL)扩增人外周血分离的单个核细胞,细胞培养分别按5×106/mL、6×106/mL和7×106/mL的密度,加入6孔培养板。第6d加入rhTNF-a(100 ng/mL)联合培养,分别于第6 d,第9 d和12 d收获细胞。从形态学、细胞表面标志方面进行鉴定。结果:显微镜观察,经过9 d诱导后,培养细胞具有典型树突细胞外形。流式细胞仪分析,6×106/mL密度的细胞培养组培养到第9天最宜。结论:细胞具有典型的DC的形态特征,细胞表型及功能实验证实其DC的特性,说明建立的血清培养基联合细胞因子rhGM-CSF、rhIL-4和rhTNF-a体外诱导DC的方法是切实可行的。     

葡聚糖磁性纳米颗粒外加磁场对人树突状细胞基因转染效率的研究

目的研究葡聚糖磁性纳米颗粒（the dextran coated magnetic iron oxide nanoparticles,DMN）在外加钕一铁一硼稀土固定磁场的作用下对人树突状细胞转染效率以及安全性的影响。方法先通过磁力计对DMN进行分析;再将修饰有多聚赖氨酸（Poly-L—Lysine,PLL）的DMN携带绿色荧光蛋白pEGFP—Cl质粒报告基因,在钕-铁-硼稀土周定强磁场的作用下,体外转染人树突状细胞,用荧光显微镜直接观察和流式细胞仪检测来评价外加磁场对DMN作为人树突状细胞转染载体效率的影响;在转染后采用MTT比色法测定在磁场干预下的DMN对人树突状细胞增殖和功能的影响以了解其细胞毒性。结果DMN的核心直径〈30nm,具有明硅的超顺磁性,比饱和磁化强度也明显高于相同Fe3O4含量的普通磁块;DMN作为基因载体在外加磁场作用下,转染12h即可将报告基因转染至人树突状细胞内并成功表达,在荧光显微镜下可观察到绿色荧光细胞,24h转染率可达到最高（约为27％）,转染效率较未加磁场组提高了2～4倍。而且转染后的人树突状细胞增殖活性及功能未因DMN外加磁场及其作用时间的长短而受到影响。结论超顺磁性的DMN在外加磁场作用下可以明显、安全、有效地提高对人树突状细胞的转染效率。     

耐受性树突状细胞

树突状细胞(DC)是体内功能最强的抗原提呈细胞,是一异质性的细胞群体,在免疫调节中扮演着双重角色.随着免疫学的发展,它在诱导器官移植耐受中的作用越来越受到重视,对其作用机制的研究也有了很大的进展.如何利用DC诱导抗原特异性免疫耐受并维持其耐受状态成为研究热点,并在此基础上提出了耐受性DC的概念.     

人咽鳞癌Fadu细胞RNA负载人树突状细胞后体外诱导特异性CTL的研究

目的:探讨咽鳞癌细胞总RNA转染的树突状细胞(DC)疫苗体外诱导特异性抗肿瘤免疫的能力.方法:分离人脐血单个核细胞,经重组人粒细胞巨噬细胞集落刺激因子(rhGM-CSF)、重组人IL-4(rhIL-4)诱导不成熟DC(iDC),提取人咽鳞癌细胞FaDu总RNA后,转染入人iDC,成为FaDu RNA/DC疫苗,用流式细胞仪检测DC表面分子CD40、CDS0、CD83、CD86、HLA-DR的表达,混合淋巴细胞反应测定DCs刺激同种异基因T细胞增殖能力.用LDH法评估转染肿瘤总RNA的DC瘤苗的细胞毒性T淋巴细胞反应.结果:与转染前比较,人咽鳞癌细胞FaDu总RNA转染后脐血单核细胞来源DCs表面CD40、CD80、CD83、CD86、HLA-DR分子水平明显升高(P均<0.05);可显著促进T细胞增殖,在体外能诱导高效而特异的抗下咽癌免疫效应(P<0.05).结论:人咽鳞癌细胞的总RNA转染的DC肿瘤疫苗能诱导CD8+,CD4+T细胞免疫,是较有临床应用前景的下咽癌免疫治疗方法.     

胸腺树突状细胞对胸腺细胞凋亡的促进作用

小鼠胸腺细胞在体外培养一定时间后自发出现凋亡,在与小鼠胸腺树突状细胞(MTSC4)共育后,其凋亡过程可被明显加速;与此相反,小鼠胸腺上皮细胞(MTECI)有抑制凋亡的作用.与MTSC4共育后的胸腺细胞中不仅CD4⁺CD8⁺双阳性细胞明显减小,而且CD4⁺CD8⁺单阳性细胞也减少.提示胸腺基质细胞可通过其对细胞凋亡的促进作用参与胸腺内的阴性选择,并提示阴性选择可能在胸腺髓质区仍在进行.     

重组腺相关病毒2型转导人外周血单核细胞来源树突状细胞的研究

To find out the infection efficiency of recombinant adeno-as sociated virus 2-mediated exogenou s genes in human peripheral blood monocyte-derived dendritic cells(D Cs),the process of transfection wa s investigated by FITC-labeled rAA V2,and observed under confocal mic roscope.Newly separated dendritic cells were tranfected by rAAV2-luc and rAAV2-GFP at different MOI,and transfection efficiency were detec ted by luminometer for rAAV2-luc a nd flow cytometry for rAAV2-GFP.Th e results were elucidated in four different assay systems:(1)60min w as needed for rAAV2 to bind on den dritic cells,and got into cells in the following 10min;(2)the express ion of luc could be detected at th e MOI as low as 1×10~5v.g/cell,and the expression plateau was reached by the MOI of 10~6～10~7v.g/cell,furt her increase of MOI had no functio n on expression level;(3)transgene expression was detected after 48h, and maintained a higher expression level from 96h to 240h after infec tion;(4)7days postinfection of rAA V2-GFP,5%～18% dendritic cells were GFP positive. These data suggest th at rAAV2 vector can efficiently in fect monocyte-derived dendritic ce lls and mediate exogenous gene exp ression,and that the application o f rAAV2 as vector may be useful fo r gene transfer to dendritic cells in ex vivo immunotherapy.     

大鼠骨髓来源未成熟与成熟树突状细胞的对比研究

目的:对比培养大鼠骨髓来源的未成熟树突状细胞与成熟树突状细胞,并从形态学、表型及功能检测等多方面进行对比研究,为后续的实验做出基础研究。方法:大鼠脱臼法处死后取两侧胫骨、股骨,PBS冲洗骨髓腔收集骨髓细胞,经GM-CSF和IL-4刺激培养六天后,对比研究经LPS刺激组与未经LPS刺激培养组细胞状况。结果:①成熟树突状细胞悬浮生长,集落分散,扫描电镜下见其突起数目明显多于未成熟树突状细胞。②成熟树突状细胞高表达表面标记分子CD80、CD86、MHCⅡ,而未成熟树突状细胞均低表达。③成熟树突状细胞培养基上清中IL-12水平高,而未成熟树突状细胞培养基上清中IL-12水平低。④成熟树突状细胞具有强的刺激T细胞增殖能力,而未成熟树突状细胞基本不具有诱导T细胞增殖能力。结论:未成熟状态的树突状细胞具备致耐受原性,可抑制T细胞的应答,而成熟状态的树突状细胞由于获得了免疫刺激潜能从而会对炎性刺激做出反应。     

Dengue virus infection induces autophagy: an in vivo study

Background

We and others have reported that autophagy is induced by dengue viruses (DVs) in various cell lines, and that it plays a supportive role in DV replication. This study intended to clarify whether DV infection could induce autophagy in vivo. Furthermore, the effect of DV induced autophagy on viral replication and DV-related pathogenesis was investigated.

Results and conclusions

The physiopathological parameters were evaluated after DV2 was intracranially injected into 6-day-old ICR suckling mice. Autophagy-related markers were monitored by immunohistochemical/immunofluorescent staining and Western blotting. Double-membrane autophagic vesicles were investigated by transmission-electron-microscopy. DV non-structural-protein-1 (NS1) expression (indicating DV infection) was detected in the cerebrum, medulla and midbrain of the infected mice. In these infected tissues, increased LC3 puncta formation, LC3-II expression, double-membrane autophagosome-like vesicles (autophagosome), amphisome, and decreased p62 accumulation were observed, indicating that DV2 induces the autophagic progression in vivo. Amphisome formation was demonstrated by colocalization of DV2-NS1 protein or LC3 puncta and mannose-6-phosphate receptor (MPR, endosome marker) in DV2-infected brain tissues. We further manipulated DV-induced autophagy by the inducer rapamycin and the inhibitor 3-methyladenine (3MA), which accordingly promoted or suppressed the disease symptoms and virus load in the brain of the infected mice.We demonstrated that DV2 infection of the suckling mice induces autophagy, which plays a promoting role in DV replication and pathogenesis.     

职业献血员中人类T淋巴细胞白血病病毒感染状况的分析

了解陕西,甘肃,青海,宁夏四省区职业献血员中人类T淋巴细胞白血病病毒（HTLV）的感染状况,以便为在职业献血员中开展HTLV普检提供一定的参考依据。采用双抗原夹心ELISA法检测了四省区10个单采浆站的7416份血浆样本。结果 HTLV（1＋2）抗体阳性7例,总阳性率0．09％,其中男性4例,感染率0．09％,女性3例,感染率0．10％;18－25年龄组2例,感染率0．09％,25－35年龄组4例,感染率0．10％,35－45年龄组1例,感染率0．08％。经过分析比较发现,HTLV感染率在职业献血员中与所报道的正常人群的感染率无显著差异,同时发现,在职业献血员中,HTLV感染的阳性率无性别差异,无年龄差异。     

Immunopathogenesis of dengue virus infection

Dengue virus infection causes dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS), whose pathogeneses are not clearly understood. Current hypotheses of antibody-dependent enhancement, virus virulence, and IFN-gamma/TNFalpha-mediated immunopathogenesis are insufficient to explain clinical manifestations of DHF/DSS such as thrombocytopenia and hemoconcentration. Dengue virus infection induces transient immune aberrant activation of CD4/CD8 ratio inversion and cytokine overproduction, and infection of endothelial cells and hepatocytes causes apoptosis and dysfunction of these cells. The coagulation and fibrinolysis systems are also activated after dengue virus infection. We propose a new hypothesis for the immunopathogenesis for dengue virus infection. The aberrant immune responses not only impair the immune response to clear the virus, but also result in overproduction of cytokines that affect monocytes, endothelial cells, and hepatocytes. Platelets are destroyed by crossreactive anti-platelet autoantibodies. Dengue-virus-induced vasculopathy and coagulopathy must be involved in the pathogenesis of hemorrhage, and the unbalance between coagulation and fibrinolysis activation increases the likelihood of severe hemorrhage in DHF/DSS. Hemostasis is maintained unless the dysregulation of coagulation and fibrinolysis persists. The overproduced IL-6 might play a crucial role in the enhanced production of anti-platelet or anti-endothelial cell autoantibodies, elevated levels of tPA, as well as a deficiency in coagulation. Capillary leakage is triggered by the dengue virus itself or by antibodies to its antigens. This immunopathogenesis of DHF/DSS can account for specific characteristics of clinical, pathologic, and epidemiological observations in dengue virus infection.     

外泌体在人类免疫缺陷病毒1型感染中的研究进展

外泌体(exosome)是动物细胞在生理或病理条件下分泌到胞外的内生性纳米微囊,在疾病发生机制和药物运输载体等研究领域成为新宠。近年来发现,外泌体在人类免疫缺陷病毒1型(human immunodeficiency virus type 1,HIV-1)感染者体内能转移病毒组分和病毒相关免疫分子,与HIV-1感染密切相关。本文以外泌体介导的HIV-1感染机制为重点,围绕外泌体与HIV-1感染的关系进行综述。     

Modulation of respiratory dendritic cells during Klebsiella pneumonia infection

Background

Klebsiella pneumoniae is a leading cause of severe hospital-acquired respiratory tract infections and death but little is known regarding the modulation of respiratory dendritic cell (DC) subsets. Plasmacytoid DC (pDC) are specialized type 1 interferon producing cells and considered to be classical mediators of antiviral immunity.

Method

By using multiparameter flow cytometry analysis we have analysed the modulation of respiratory DC subsets after intratracheal Klebsiella pneumonia infection.

Results

Data indicate that pDCs and MoDC were markedly elevated in the post acute pneumonia phase when compared to mock-infected controls. Analysis of draining mediastinal lymph nodes revealed a rapid increase of activated CD103⁺ DC, CD11b⁺ DC and MoDC within 48 h post infection. Lung pDC identification during bacterial pneumonia was confirmed by extended phenotyping for 120G8, mPDCA-1 and Siglec-H expression and by demonstration of high Interferon-alpha producing capacity after cell sorting. Cytokine expression analysis of ex vivo-sorted respiratory DC subpopulations from infected animals revealed elevated Interferon-alpha in pDC, elevated IFN-gamma, IL-4 and IL-13 in CD103⁺ DC and IL-19 and IL-12p35 in CD11b⁺ DC subsets in comparison to CD11c⁺ MHC-class II^low cells indicating distinct functional roles. Antigen-specific naive CD4⁺ T cell stimulatory capacity of purified respiratory DC subsets was analysed in a model system with purified ovalbumin T cell receptor transgenic naive CD4⁺ responder T cells and respiratory DC subsets, pulsed with ovalbumin and matured with Klebsiella pneumoniae lysate. CD103⁺ DC and CD11b⁺ DC subsets represented the most potent naive CD4⁺ T helper cell activators.

Conclusion

These results provide novel insight into the activation of respiratory DC subsets during Klebsiella pneumonia infection. The detection of increased respiratory pDC numbers in bacterial pneumonia may indicate possible novel pDC functions with respect to lung repair and regeneration.     

Comparison by flow cytometry of immune changes induced in human monocyte-derived dendritic cells upon infection with dengue 2 live-attenuated vaccine or 16681 parental strain

Dengue is an important threat for world-wide public health. Different vaccines are under development, which are currently assessed using a battery of in vitro and in vivo assays before moving on to humans. It is also important to assess vaccine characteristics on human primary cells; among them, dendritic cells, the most efficient antigen-presenting cells, are the first targets of dengue virus infection. In this study, we used flow cytometry to compare the consequences of such an infection by dengue serotype 2 live-attenuated vaccine (LAV2) or its parental strain DEN2 16681 (DEN2). Optimal conditions of infection have first been defined by a mathematical approach, and flow cytometry allowed studying modifications induced in both infected and noninfected dendritic cell populations after surface and intracellular labeling. Both DEN2 and LAV2 increased the expression of the phenotypic markers CD80, CD86, CD40, CD1a, HLA ABC and CD83, demonstrating cellular activation. Stimulated dendritic cells produced tumor necrosis factor-alpha in particular, and, to a lower extent, interleukin 6. Of importance, whereas DEN2 induced cytokine production both in the infected and noninfected populations, LAV2-induced cytokine production was restricted to the infected population. This limited activation triggered by LAV2 would be in agreement with its attenuation. In conclusion, these in vitro experiments using primary human dendritic cells may participate, in combination with other assays, to the evaluation of the immunogenicity and safety of dengue vaccine candidates.