肺炎支原体荚膜多糖与DC-SIGN结合并促进IL-10的分泌

目的 研究肺炎支原体(Mp)荚膜多糖(CPS)与树突状细胞(DC)特异性细胞间黏附分子-3-结合非整合素分子(DC-SIGN,CD09)的相互作用及其对未成熟DC(iDC)分泌IL-10和IL-12的影响.方法 提取并纯化Mp的CPS和脂质相关膜蛋白(LAMPs),用间接免疫荧光检测CPS与DC-SIGN受体的作用;ELISA法检测CPS和LAMPs作用后iDC所分泌的IL-10,IL-12水平.结果 间接免疫荧光可见Mp CPS可结合到DC表面,且DC-SIGN的特异性封闭抗体可阻断CPS与DC的结合;ELISA检测发现CPS与LAMPs共孵育可促进DC分泌IL-10(P ＜0.05),而IL-12的表达水平刺激前后无统计学的差异.结论 Mp的CPS可识别并结合DC的DC-SIGN受体,并促进未成熟DC分泌IL-10.     

5种沙眼衣原体分泌蛋白对小鼠巨噬细胞和树突状细胞吞噬功能的影响北大核心CSCD

目的探索5种沙眼衣原体分泌蛋白在体外对小鼠巨噬细胞和树突状细胞吞噬功能的影响。方法原核表达蛋白GST-CT311、GST-GIgA、GST-cHtrA、GST-OmcBc和GST-Pgp3中,同时表达了衣原体膜蛋白GST-IncA作为对照,经谷胱甘肽巯基转移酶（GST）磁珠纯化、PreScission蛋白酶切除GST标签后得到蛋白CT311、GIgA、cHtrA、OmcBc、Pgp3以及IncA。取C3H/HeJ小鼠骨髓细胞制备巨噬细胞和树突状细胞,分别用100μg/ml和500μg/ml的蛋白质预处理巨噬细胞和树突状细胞,4h后加入荧光珠,1h后固定细胞,直接免疫荧光法计数每100个细胞吞噬荧光珠的平均数量（吞噬量）及每100个细胞中吞噬的细胞百分比（吞噬率）。结果高、低浓度蛋白质组对巨噬细胞及树突状细胞的吞噬率均无明显影响;与无处理组相比,LPS以及低浓度（100μg/ml）的各蛋白组对巨噬细胞和树突状细胞的吞噬量无明显影响;高浓度组（500μg/ml）的Pgp3、cHtrA及CT311预处理的巨噬细胞和树突状细胞吞噬量明显升高,GIgA、OmcBc以及IncA对巨噬细胞和树突状细胞的吞噬量无明显影响。结论在体外,沙眼衣原体分泌蛋白Pgp3、cHtrA及CT311可以促进巨噬细胞和树突状细胞的吞噬功能,这可能有助于沙眼衣原体在宿主体内的播散感染。     

罗勒多糖对树突状细胞表面分子表达的影响

目的：观察罗勒多糖对人外周血单核细胞来源的树突状细胞（Dendritic cell，DC）表面分子表达的影响，探讨其抗肿瘤免疫机制。方法：从正常人外周血分离获得单核细胞，加入含10％胎牛血清、CM-CSF及IL-4的RPMI1640，37℃培养5天，实验组加入罗勒多糖，对照组加入PBS，流式细胞仪检测细胞表面分子的表达。结果：在细胞因子的诱导下，CD14^＋单核细胞逐渐分化为DC，罗勒多糖作用组与对照组DC均表达CD209、CD80、CD83、CD86、CD1a和HLA-DR，与对照组相比，罗勒多糖组DC表面分子CD80和HLA-DR的表达均明显上调。结论：罗勒多糖能够调节DC表面分子CD80和HLA-DR的表达，这可能是罗勒多糖发挥其抗肿瘤免疫的机制之一。     

树突状细胞表达分子DC-SIGN在HIV-1感染传播中的作用

DC-SIGN是一种特异性表达于树突状细胞(DC)表面的Ⅱ型跨膜蛋白，它可以通过识别人HIV-1包膜糖蛋白gp120介导DC与HIV-1特异性粘附，并增强HIV-1感染力，在HIV-1水平和垂直传播过程中起重要作用。分析DC-SIGN影响HIV-1传播过程的分子机制有利于探讨HIV-1感染的免疫和基因治疗，本文拟就有关问题作一综述。     

17β-雌二醇调节小鼠淋巴结树突状细胞的表型和吞噬功能

为探索17β-雌二醇(E2)对免疫应答能力的调节是否与树突状细胞(DC)的成熟和功能相关,用Metrizamide密度梯度离心方法分离BALB/c小鼠淋巴结内的淋巴细胞得到DC,不同浓度的E2处理DC 24 h后,使用PE标记的单抗CD11c和FITC标记的单抗MHC I/MHC II/CD40/CD54/CD80/CD86、IL-10/TNF-α以及右旋糖酐(dextran)双标DC,流式细胞仪分别检测其表型和胞内细胞因子的表达及吞噬能力的变化。结果显示,不同浓度的E2处理DC 24 h后,MHC分子、黏附分子CD54和共刺激分子CD86与对照组相比显著提高,而CD40显著降低,但CD80的表达无明显改变。胞内细胞因子IL-10和TNF-α的表达水平随E2的处理而显著增加,其中TNF-α的变化呈剂量依赖性。与对照组相比,DC的吞噬能力随E2的处理浓度增加而显著降低。以上结果表明,E2能够改变DC的成熟和功能,这提示E2对机体的免疫应答的影响可能通过DC的改变而改变。     

CD8~ 的树突状细胞研究进展

CD8 的树突状细胞是树突状细胞中的一个特殊的群体 ,可能主要来源于胸腺前体细胞 ,其主要特点是高度表达CD8分子和一些T细胞的表面标记 ,在功能上主要表现为对CD4 T细胞的活化的同时 ,又介导其凋亡 ;而对CD8 T细胞的作用是通过抑制内源性IL 2的产生从而抑制其生物学作用。     

肺脏树突状细胞表面共刺激分子在小鼠哮喘模型中的表达

目的 通过检测哮喘小鼠肺组织中树突状细胞(dendritic cells,DC)表面共刺激分子的表达以及细胞因子分泌的能力,探讨哮喘发生免疫耐受缺陷的原因.方法 Balb/c小鼠60只,分为3组(每组20只):哮喘组、磷酸盐缓冲液(PBS)对照组、健康对照组.对3组小鼠取肺组织做病理观察,行支气管肺泡灌洗液(BALF)计数细胞并分类,ELISA检测血清特异性IgE(sIgE)及BALF中细胞因子的水平.分离、培养肺脏DC,用流式细胞仪(FACS)测CD11c表达,并进一步用FACS分析哮喘小鼠DC表面共刺激分子CD11cCD80、CD11cCD86表达的变化.结果 哮喘小鼠肺组织表现为以嗜酸性粒细胞、淋巴细胞浸润为主的炎症改变,BALF中嗜酸性粒细胞计数显著增加(P＜0.01),血清sIgE水平显著升高(P＜0.01).与PBS对照组比较,哮喘小鼠CD11cCD80、CD11cCD86表达上调(P＜0.01),其分泌IL-10细胞因子的水平明显下降.结论 肺脏DC可能通过上调CD11cCD80、CD11cCD86在哮喘的免疫耐受缺陷中发挥作用.     

树突状细胞特异表面分子DC-SIGN的研究进展

DC-SIGN是一种特异表达于树突状细胞(DC)表面的Ⅱ型跨膜蛋白,在机体生理和病理免疫调节中发挥着重要作用,可以与ICAM-3结合,从而介导DC与T细胞的相互作用,其CRD区可以与HIV-1、HCV、结核杆菌等多种病原体表面糖蛋白结合,从而促进病原体感染。最近的研究表明DC-SIGN与肿瘤免疫、免疫逃避也密切相关。     

烟草烟雾提取物促进髓样树突状细胞共刺激分子的表达

目的通过体外实验研究烟草烟雾提取物(CSE)对小鼠髓样树突状细胞(mDC)成熟的影响及可能的机制。方法小鼠骨髓来源的单个核细胞加入粒-单集落刺激因子(GM-CSF)、白细胞介素-4(IL-4)和含100 mL/L胎牛血清的RPMI1640培养液诱导出可供实验用的高纯度的未成熟DC(iDC),分空白对照组和CSE刺激组;CSE刺激组按15 mL/L的终浓度加入CSE,两组继续培养24 h,流式细胞检测技术检测mDC的共刺激分子CD40、CD80、CD86和MHC-Ⅱ的表达。结果空白对照组的mDC低表达CD40、CD80、CD86和MHC-Ⅱ;CSE刺激后mDC表达CD40、CD80和MHC-Ⅱ比空白对照组明显增加,差异有统计学意义(P0.05)。结论烟草烟雾提取物促进小鼠骨髓来源的mDC的CD40、CD80和MHC-Ⅱ的表达。     

肺炎支原体肺炎患儿外周血CXCL8 及其mRNA 表达

目的:探讨支原体肺炎患儿外周血CXCL8 及其mRNA 表达的临床意义。方法:收集2013 年10 月~2015 年3 月淮南市妇幼保健院收治的支原体肺炎患儿48 例,其中重症12 例,轻症36 例,以ELISA 法检测患儿血清CXCL8 含量,PCR法检测患儿外周血单个核细胞内CXCL8 mRNA 水平。以GAPDH 为参照,以lgcDNA/ lgGAPDH 比值代表其最终mRNA 水平。结果:支原体肺炎患儿外周血血清CXCL8 含量及外周血单个核细胞内CXCL8 mRNA 水平分别为(298.917±51.860)pg/ ml、(1.848±0.525)lgcDNA/ lgGAPDH,与正常对照相比差异均有显著统计学意义(P<0.05)。进一步观察发现,重症患儿外周血CXCL8 及其mRNA 进一步升高,与轻症组相比,血清CXCL8 含量差异无显著统计学意义统计学意义(P>0.05),而CXCL8mRNA 水平差异有显著统计学意义(P<0.05)。急性期以红霉素静脉注射7 ~10 d,使患儿病情得以明显控制,咳嗽症状减轻,肺部炎症逐渐改善,病情得到有效控制,再以阿奇霉素序贯治疗2 ~3 周,患儿病情逐步由急性期转为恢复期,此时患儿外周血CXCL8 及其mRNA 水平明显降低,与急性期相比,差异有显著统计学意义(P<0.05)。结论:支原体肺炎患儿外周血CXCL8 及其mRNA 表达水平增高,并与病情的严重程度相关。CXCL8 参与支原体肺炎的发病过程,并对病情的轻重程度和转归有一定的提示作用。阿奇霉素可通过抑制肺炎支原体增殖途径降低患儿血清中CXCL8 含量、下调CXCL8 mRNA 的表达,逐渐抑制由肺炎支原体介导的免疫损伤。     

Relationships among capsular structure, phagocytosis, and mouse virulence in Klebsiella pneumoniae.

Klebsiella pneumoniae strains of the K2 capsular serotype are usually highly virulent in mice, which is in contrast to the low virulence of most other serotypes. Here we used a genetic approach to examine the relative contribution of capsule type to the virulence of K. pneumoniae in mice. We used wild-type strains expressing capsular polysaccharide (CPS) serotypes K2 (strain KPA1) and K21a (strains KPB1 and KPC1), which were then used to construct capsule-switched derivatives. The close proximity of the cps gene cluster to selectable his markers made it possible to mobilize the cps genes by conjugation from one serotype (donor) to another (recipient) and to obtain recombinants in which interserotype switching had occurred by reciprocal recombination. Each capsule-switched derivative examined of the KPA and KPC strain backgrounds produced a CPS that was immunologically and structurally identical to that of the donor. Strain background was confirmed by demonstrating restriction fragment length polymorphism patterns identical to those of the respective recipients. The parent strains were then compared with capsule-switched recombinants for phenotypic properties associated with virulence. Clearance from the bloodstreams of mice was rapid in serotype K21a strains of either wild-type or recombinant origin, whereas K2 strains remained viable in the blood during the period examined. These differences appeared to be dependent upon the CPS type but independent of strain background. Binding to macrophages was higher in K21a strains than in those with the K2 capsule and was also independent of the strain background. Both blood clearance and macrophage-binding activities were completely inhibited by yeast mannan, suggesting that they were mediated via the macrophage mannose receptor. The K2 parent strain was highly virulent to mice (50% lethal dose [LD50], 3 x 10(3)), while the K21a parent strains demonstrated low virulence (LD50, > 2 x 10(8)). Interestingly, the virulence of recombinant KPC10(cpsK2), originally of the KPC1(cpsK21a) background, was intermediate (LD50, 4 x 10(5)). In contrast, both cpsK21a recombinants of the originally virulent KPA1 (cpsK2) background became nearly avirulent (LD50, > 2 x 10(8)). Six additional serotypes (K12, K24, K32, K55, K62, and K67) were examined, and all showed a positive correlation between the ability of the Klebsiella serotype to interact with a human mannose receptor, as expressed by Cos I cell recombinants, and the LD50 of the serotype. These results suggest that expression of a capsule which is recognized by the mannose receptor markedly affects the interaction with macrophages and blood clearance.(ABSTRACT TRUNCATED AT 400 WORDS)     

Enzyme-linked immunosorbent assay for detection of antibodies against Streptococcus pneumoniae capsular polysaccharides.

The development of an assay to measure the human immune response to pneumococcal capsular polysaccharides is described.     

Humoral immune response in chinchillas to the capsular polysaccharides of Streptococcus pneumoniae.

Vaccines made from the capsular polysaccharides of Streptococcus pneumoniae have been shown to reduce the incidence of pneumococcal disease in certain populations and have recently been evaluated for their ability to elicit protection against experimental pneumococcal otitis media in a chinchilla model. In this study, chinchillas were vaccinated with a dodecavalent preparation of pneumococcal capsular polysaccharides (PCP) to obtain more information on the immunogenicity of these polysaccharide antigens. All 12 PCP types elicited an antibody response, but the optimum PCP dose and the kinetics of the antibody response varied among types. Immunological paralysis was demonstrated with an immunogenic dose of PCP after primary immunization with a large PCP dose (25 micrograms or more). Pertussis vaccine acted as neither an immunoadjuvant nor an immunosuppressant in the serum antibody response to type 7F PCP in chinchillas.     

Molecular aspects of microparticle phagocytosis by dendritic cells

The ability of immature dendritic cells (iDCs) derived from human peripheral blood mononuclear cells to phagocytose poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) as compared to polystyrene MPs and the molecular aspects of this phagocytosis were investigated. Treating iDCs with PLGA or polystyrene fluorospheres of approximately 3 microm in diameter resulted in the internalization of the particles as evidenced by confocal laser scanning micrographs. This uptake of fluorospheres by DCs was decreased by pretreatment of cells with cytochalasin D or by incubation with the fluorospheres at 4 degrees C, and was sensitive to EDTA and trypsin pretreatments in a dose-dependent manner. In agreement with our previous studies, treatment of iDCs with PLGA MPs, but not with polystyrene MPs, led to DC maturation, as measured by increase in release of the autocrine maturation cytokine, tumor necrosis factor-alpha, which was dependent on ratio of PLGA MPs to DCs. Taken together, this work begins to address the role of phagocytosis on PLGA MP-induced DC maturation and the molecular mechanisms involved.     

纳米粒子-siRNA复合物抑制脐血树突状细胞SOCS1基因表达的实验研究

目的:构建复合纳米粒子载体,传递siRNA序列,抑制脐血树突状细胞SOCS1基因表达.方法:构建PEI包覆的以SiO2和Fe3O4为主要成分的复合纳米粒子载体,以LipofectamineTM2000为对照,琼脂糖凝胶电泳检测纳米粒子-siRNA的结合效率;荧光显微镜和流式细胞术检测纳米粒子-SOCS1-siRNA序列被细胞摄入的效率;Western blot检测纳米粒子-siRNA复合物转染脐血树突状细胞后对SOCS1基因表达的抑制.MTT法检测纳米粒子-SOCS1-siRNA处理的脐血DCs对肿瘤细胞的杀伤活性.结果:纳米粒子可以高效结合siRNA序列,纳米粒子-SOCS1-siRNA序列可被脐血树突状细胞摄取,但是单独的纳米粒子抑制SOCS1基因表达效率比较低,在外加磁场的作用下,基因沉默作用显著增强,抗肿瘤作用也相应提高.结论:纳米粒子载体传递siRNA安全性好,效率高,可以高效沉默脐血树突状细胞SOCS1基因表达,能为设计更有效的以树突状细胞为基础的抗肿瘤疫苗提供新思路和实验依据.     

Opsonin-reversible resistance of Mycoplasma pneumoniae to in vitro phagocytosis by alveolar macrophages.

Several species of mycoplasmas are responsible for respiratory disease in animals and man. As yet, little is known about the interaction of these pathogens with alveolar macrophages, one of the primary components of pulmonary resistance to infections. The present study was undertaken to develop an in vitro model to examine this organism-cell interaction, using a human pathogen, mycoplasma pneumoniae, and normal guinea pig alveolar macrophages. During a 24-h incubation of M. pneumoniae with a monolayer of macrophages, mycoplasmas were found to attach directly to the surface of the cells without inducing significant phagocytosis. Ultrastructurally, the organisms appeared bound to the cell membrane by their characteristic attachment organelles. Only after the addition of specific anti-mycoplasma serum were cells able to engulf attached and surrounding organisms. These data suggest that the interaction of M. pneumoniae and alveolar macrophages is a potentially important aspect of disease pathogenesis, and immune factors which might alter this interaction merit further examination.     

Release of Mycoplasma pneumoniae substances after phagocytosis by guinea pig alveolar macrophages.

Antibody-opsonized Mycoplasma pneumoniae cells with various radioactive markers were sedimented onto monolayers of guinea pig alveolar macrophages (AM). After 2 h of incubation, about 50% of the activity of [3H]palmitate-labeled mycoplasmas was associated with AM. Nonspecific attachment of the opsonized mycoplasmas to AM-free plastic surface areas was negligible. The occurrence of phagocytosis was proven by electron microscopy and monitoring of AM surface-bound antigen by 125I-labeled F(ab)2 fragments. The activity of [3H]palmitic acid-labeled mycoplasmas was only slowly released into the supernatant. About 55% of the activity remained AM-associated up to 70 h after phagocytosis. After phagocytosis of [3H]thymidine-labeled cells, about 70% of the radioactivity found non-precipitable by trichloracetic acid. 3H-amino acid-labeled protein was released to 50% within 8 h. Supernatants and AM were tested for M. pneumoniae antigen with enzyme-linked immunosorbent assay. Considerable amounts of antigenically active material could be found in the supernatant within 8 h. This antigen was totally inactivated by heat (80 degrees C). Trypsin treatment (1 mg/ml, 10 min) reduced the antigenicity by 80%. The results suggest a selective release of microbial material after phagocytosis.     

Pneumococcal polysaccharides interact with human dendritic cells

Dendritic cells (DCs) are critical antigen presentation cells whose influence on murine immune responses to polysaccharide antigens has only recently been elucidated. Little is known about human DC-polysaccharide interactions. We set out to study the interaction between human monocyte-derived DCs and pneumococcal capsular polysaccharides (PPS) in vitro. Immature DCs were generated from peripheral blood monocytes and incubated with fluorescein isothiocyanate-labeled PPS type 9N or 14 for assessment of uptake. DCs were exposed to PPS type 1, 6B, 9N, 14, 19F, or 23F in the absence or presence of Escherichia coli lipopolysaccharide (LPS) for assessment of phenotypic DC maturation and cytokine production. PPS were taken up by immature DCs and proceeded to HLA-DR+ and lysosome-associated membrane protein-1+ late endosomal compartments. Uptake was reduced in the presence of cytochalasin D and wortmannin, suggesting that both cytoskeletal rearrangements and phosphatidylinositol 3-kinase activation may be required for internalization. None of the PPS tested induced DC phenotype changes, maturation, or interleukin-12 (IL-12)/IL-10 production. However, PPS were capable of modulating the response of the DCs to a second signal such as LPS. Exposure of DCs to PPS in the presence of LPS resulted in an altered cytokine balance with significantly increased IL-10 production and reduced IL-12 production compared to LPS alone. This effect was not seen using the control antigen tetanus toxoid. DC-pneumococcus interaction may affect subsequent immune responses to pneumococci, as an altered cytokine balance may have a profound effect on DC-driven T-cell priming.