单核-巨噬细胞的分化和功能研究进展

单核-巨噬细胞系统的发现已愈百年。近年发现单核-巨噬细胞系统不仅在机体的自身稳态、免疫监视和抗感染等方面发挥关键作用,还参与了众多疾病的发生和发展。在发育来源上,成年个体的单核-巨噬细胞系统的成员不仅来源于骨髓造血,还来源于胚胎原始造血;在功能上,单核-巨噬细胞系统更是展现出广泛的异质性,尤其是近年来发现该系统具有重要的免疫调节功能。阐明单核-巨噬细胞系统的分化、激活、效应的细胞和分子机制,对深刻认识机体自身稳态、免疫应答、以及相关疾病发生发展,最终建立有效的干预手段,具有重要的理论和实际意义。     

单核/巨噬细胞脂质代谢和炎症在动脉粥样硬化中的作用

动脉粥样硬化(AS)是慢性炎症性疾病,以胆固醇在动脉管壁积聚形成斑块为特征,炎症与脂质代谢相伴并相互协同共同促进AS病变进展。单核-巨噬细胞是机体防御系统的重要细胞之一,在AS早期单核细胞趋化黏附至内皮下分化为巨噬细胞,巨噬细胞内胆固醇摄入、合成、流出异常引起脂质积聚形成泡沫细胞是组成脂质条纹的主要成分,其平衡机制也是对炎症反应的适应性过程。同时巨噬细胞作为炎症细胞分泌多种细胞因子,对脂质代谢过程中的多种受体和基因也具有调控作用。针对巨噬细胞脂质代谢和炎症反应的共同环节将在治疗动脉粥样硬化性疾病中发挥重要作用。     

皮肤树突状细胞亚群研究进展

皮肤树突状细胞(DC)作为重要的抗原提呈细胞,在机体免疫应答或自身耐受的发生中扮演着非常重要的角色.皮肤免疫系统中定居着多种DC亚群,主要包括表皮层中的郎格汉斯细胞(LC)与真皮层中的各种真皮DC亚群.健康皮肤中的DC亚群主要有表皮LC、真皮DC(dDC)和浆细胞DC(pDC),dDC又分为Langerin+ dDC及Langerin-dDC等.但在炎症性皮肤,如过敏性皮炎、银屑病等病变皮肤中则存在着炎症性DC亚群.DC由于其复杂的异质性群体,导致了其各亚群的特殊化功能.皮肤DC亚群的特殊化功能,为皮肤性疾病的临床治疗及新型疫苗的研发设计等都提供了良好的新策略.     

单核巨噬细胞的选择性激活及其与疾病的关系

单核巨噬细胞存在两种激活途径,即经典激活和选择性激活.既往对单核巨噬细胞在炎症过程中的作用研究侧重于其经典激活后的促炎效应,包括抗原处理、呈递、T细胞激活和促炎因子的分泌.近年愈来愈多的研究揭示了单核巨噬细胞选择性激活的重要性,如参于组织的修复、组织纤维化和血管形成.本文从单核巨噬细胞平衡调节入手,阐述选择性激活的单核巨噬细胞的表型和分子特征,及其在多种疾病发生和发展中的作用.     

幼鼠内毒素血症脾内单核-巨噬细胞等动态分布

用组织化学和生化方法探讨了幼龄大鼠内毒素血症脾急性非特异性免疫反应,腹腔注入内毒素（ｉ．ｐ．ＬＰＳ）１ｈ,脾内碱性磷酸酶（ＡＬＰａｓｅ）阳性细胞开始增多,至１２ｈ红髓和边缘区内呈现大量的ＡＬＰ阳性细胞,２４－７２ｈ这些阳性细胞逐渐减少至正常。电镜下证实这些阳性细胞多数为单核－巨噬细胞和中性粒细胞。     

单核巨噬细胞介导急性肾损伤发病的研究进展

急性肾损伤 (Acute Kidney Injury,AKI) 和慢性肾脏病 (Chronic Kidney Disease,CKD) 是最常见的肾损伤形式,已成为新的“公共健康问题”。高效识别肾脏高危易损者是目前临床精准监测、精准防治的迫切需要。肾损伤后的信号分子,特别是肾小管上皮细胞损伤后表达的小分子蛋白,能释放至尿液中,尿中水平与肾损伤程度密切相关,是新的肾损伤指标。本文围绕主要的尿液肾损伤生物标志物,介绍它们从基础发现到临床验证,再到临床应用的全过程,最后初步探讨尿液肾损伤标志物研究的未来方向。     

刺激单核巨噬细胞对肝实质及非实质细胞脂蛋白代谢的影响

本研究结果表明酵母多糖对喂正常饲料大鼠肝非实质细胞及实质细胞的^125I-HDL及^125I-LDL代谢影响不大，但可明显增加喂高脂饲料大鼠细胞对^125I-HDL及^125I-LDL的结合、内移及降解，增加胆汁中总胆酸及胆固醇的排泄，明显降低高脂饲料导致的高胆固醇血症。     

大鼠不同部位的单核/巨噬细胞功能异质性的实验研究

目的:了解生理状态下不同部位单核/巨噬细胞功能的异质性。方法:健康Wistar大鼠以灌洗法分离肺泡巨噬细胞(AM)和腹腔巨噬细胞(PM),以密度梯度离心法分离外周血单核细胞(Mo)。采用无色孔雀绿比色法、流式细胞仪及放免法,分别测定不同部位单核/巨噬细胞的非特异性吞噬功能,IA抗原的表达及IL6、IL10的分泌水平。结果:AM的吞噬功能最强,Mo最弱。PM可高表达IA,而AM及Mo的表达量较低。PM分泌IL10的水平最高,Mo分泌IL6的水平最高。结论:生理状态下单核/巨噬细胞的功能及表型存在异质性。AM在天然免疫中有重要作用。PM可能在获得性免疫及拮抗炎症反应中有重要作用。     

神经营养素在单核巨噬细胞系统上的表达与功能

神经营养素与免疫系统关系密切,单核巨噬细胞系统作为免疫系统的重要组成成份,也表达神经营养素及其受体。神经营养素对单核巨噬细胞系统的分化成熟、趋化性、分泌活性物质均有一定的影响。     

PKC介导单核/巨噬细胞分化过程中间质标志物的表达变化

目的探讨单核/巨噬细胞分化过程中,PKC调控间质标志物表达变化的机制。方法以PMA诱导的单核细胞分化成巨噬细胞过程为研究对象,利用流式细胞术检测巨噬细胞表面标志物的表达;随后利用鬼笔环肽染色比较分化前后细胞长短轴的比例变化;利用Western blot法检测分化前后间质标志物相关蛋白的表达变化以及PKC抑制剂对间质标志物表达的影响。结果单核细胞向巨噬细胞分化过程中,间质标志物表达增加,并且这种变化受到PKC的调控。结论PKC介导单核/巨噬细胞分化过程中间质标志物的表达变化。     

Gene expression profiling during differentiation of human monocytes to macrophages or dendritic cells

Macrophages and dendritic cells (DC) are APC, which regulate innate and adaptive immune responses. Macrophages function locally mainly, maintaining inflammatory responses in tissues, whereas DC take up microbes, mature, and migrate to local lymph nodes to present microbial antigens to na?ve T cells to elicit microbe-specific immune responses. Blood monocytes can be differentiated in vitro to macrophages or DC by GM-CSF or GM-CSF + IL-4, respectively. In the present study, we performed global gene expression analyses using Affymetrix HG-U133A Gene Chip oligonucleotide arrays during macrophage and DC differentiation. During the differentiation process, 340 and 350 genes were up-regulated, and 190 and 240 genes were down-regulated in macrophages and DC, respectively. There were also more that 200 genes, which were expressed differentially in fully differentiated macrophages and DC. Macrophage-specific genes include, e.g., CD14, CD163, C5R1, and FcgammaR1A, and several cell surface adhesion molecules, cytokine receptors, WNT5A and its receptor of the Frizzled family FZD2, fibronectin, and FcepsilonR1A were identified as DC-specific. Our results reveal significant differences in gene expression profiles between macrophages and DC, and these differences can partially explain the functional differences between these two important cell types.     

Expression of beta-defensin 1 and 2 mRNA by human monocytes,macrophages and dendritic cells

Human beta-defensins are broad-spectrum antimicrobial peptides known to be produced by epithelial cells. It was recently shown that beta-defensins also display chemotactic activity for dendritic cells (DC) and T cells, and thus may serve to link innate and adaptive immunity. The aim of the present study was to explore expression of mRNA for these peptides in mononuclear phagocytes and DC. The results revealed that monocytes, monocyte-derived-macrophages (MDM), and monocyte-derived-dendritic cells (DC) all express human-beta-defensin-1 (hBD-1) mRNA. hBD-1 mRNA expression by monocytes and MDM was increased after activation with interferon-gamma (IFN-gamma) and/or lipopolysaccharide (LPS) in a dose- and time-dependent fashion. Alveolar macrophages showed an intense hBD-1 expression, which could not be further increased. Expression of hBD-1 mRNA by immature DC was low, and increased considerably after maturation. Monocytes, MDM, alveolar macrophages and DC showed a limited expression of human beta-defensin-2 (hBD-2) mRNA, which could only be increased in monocytes and alveolar macrophages by IFN-gamma and/or LPS in a dose- and time-dependent fashion. Immunocytochemical stainings demonstrated the expression of hBD-2 peptide by freshly isolated blood monocytes and alveolar macrophages in cytospin preparations.     

Ontogeny and characterization of Factor XIIIa+ cells in developing human skin

Factor XIIIa (FXIIIa), a coagulation transglutaminase, is a cytoplasmic marker for dermal dendritic cells reported to be bone marrow-derived, phagocytic and antigen-presenting. In non-inflamed skin, these cells populate the papillary dermis in a perivascular distribution. They are increased in dermatoproliferative disorders and have been implicated as dermal stimulants for psoriatic hyperkeratosis. Since developing skin provides an example of dermal influence on the epidermis, we evaluated the presence of FXIIIa⁺ cells in human fetal skin to determine whether their location would suggest a role in morphogenetic events in the skin. Embryonic and fetal skin of progressive estimated gestational ages (EGA) was examined using immunocytochemistry with a polyclonal antibody to FXIIIa. At 6 weeks EGA, globular FXIIIa⁺ cells were present in the hypodermis. By 7–8 weeks, a compact sub-epidermal network of fusiform FXIIIa⁺ cells was also evident. By 11–12 weeks, the sub-epidermal cellular network was no longer FXIIIa⁺, but discrete FXIIIa⁺ dendritic cells were present in the reticular dermis. With advancing gestational age, FXIIIa⁺ dendritic cells populated the papillary dermis in a perivascular distribution. This adult-like distribution persisted through 22 weeks EGA, the oldest specimen examined. Because FXIIIa⁺ cells were evident in embryonic skin before the onset of bone marrow hematopoietic function, the skin was double-labeled with the FXIIIa antibody and with monoclonal antibodies to CD45 (marker for bone marrow-derived cells), CD68 (marker for macrophages) and HLA-DR (class II major histocompatibility antigen). Most of the FXIIIa⁺ dendritic cells did not colocalize CD45, but were CD68⁺; some cells did react with the HLA-DR antibody. Notably, the FXIIIa⁺ cells of the sub-epidermal network in the 7 weeks EGA specimens did not react with the other antibodies. We conclude that FXIIIa⁺ cells are first present in embryonic hypodermis and sub-epidermal dermis and later they are distributed in the papillary dermis in a perivascular pattern. In embryonic skin FXIIIa⁺ cells are not exclusively dendritic. Our data support the idea that cells that express FXIIIa do not constitute a unique bone marrow-derived cell type, but that multiple cell types produce FXIIIa.     

人脐带血来源树突状细胞、巨噬细胞和单核细胞体外培养及鉴定

目的建立从人脐带血体外诱导扩增树突状细胞、巨噬细胞和单核细胞的方法。方法从正常人脐带血中分离出单核细胞,经3种细胞因子—重组人粒细胞-巨噬细胞集落刺激因子(rh GM-CSF)、重组人白细胞介素4(rh IL-4)和重组人肿瘤坏死因子(rh TNF-α)联合诱导培养,7 d后收获细胞,并利用光学显微镜、免疫组化的方法进行鉴定。结果培养收获了高纯度的树突状细胞、巨噬细胞、单核细胞,细胞高水平表达CD1a、CD86、CD68和CD14。结论人脐带血单核细胞经细胞因子诱导培养可以得到大量的成熟树突状细胞、巨噬细胞和单核细胞。     

Differentiation of human dendritic cells from monocytes in vitro

Since either macrophages (M?) or dendritic cells (DC) differentiate from monocytes (MO) depending on culture conditions, we investigated the relationship of the DC and M? differentiation pathways. Culturing MO-enriched blood mononuclear cells with M? colony-stimulating factor (M-CSF) or with granulocyte/M? (GM)-CSF induced M? with a different morphology and CD14/CD1a expression. In contrast, in cultures with GM-CSF and interleukin (IL)-4, cells rapidly became nonadherent and acquired DC morphology, ultrastructure, CD1a expression, and most DC markers; they lost membrane CD14 and CD64 and capacity of phagocytosis, displayed less CD68 than M?, but retained nonspecific esterase activity. These DC directly developed from MO without proliferation inasmuch as only day 0 FACS-sorted MO, but not small CD14^? cells, differentiated into DC when cultured with GM-CSF and IL-4, or to M? with M-CSF. While overall cell numbers declined, DC numbers plateaued from culture day 2 onwards, indicating that most had differentiasted by then. This differentiation was radioresistant and occurred without [³H]thymidine incorporation. Commitment to differentiate into DC with GM-CSF and IL-4 was irreversible by day 2, since discontinuing IL-4 at this point did not revert cells to M?. Alternatively, cells rapidly converted to DC when IL-4 was added from day 2 to cultures initiated with GM-CSF only. If cultures were initiated with M-CSF and switched to GM-CSF and IL-4 after 2 or 5 days, about half of the cells still converted to DC. Thus, the capacity of MO and even of M? to differentiate into DC was conserved for at least this period. The increased capacity to stimulate the mixed leukocyte reaction correlated with the relative number of CD1a^? cells at any time and under each condition tested, a confirmation that these cells functionally qualify as DC. Thus, MO and even M? can be directed to differentiate into DC depending on the cytokine microenvironment.     

人静脉移植物中MCP-1的表达

目的：探讨人静脉移植物中单核细胞趋化蛋白-1（MCP-1）的表达及其与巨噬细胞浸润的关系。方法：应用免疫荧光组织化学技术对30个静脉移植物再塞标本中MCP-1、CD68（巨噬细胞的标记物）、CD3l（内皮细胞的标记物）的表达进行了检测，用激光共聚焦显微镜拍片，图片用Silicon Graphics Octane进行处理。结果：在正常静脉血管中，MCP-1表达很弱；外膜中有少量CD68免疫阳性细胞，中膜和内膜中少见；CD31免疫阳性细胞仅在血管腔内皮细胞和外膜小血管中可见。在病变静脉血管，MCP-1在内皮细胞、平滑肌细胞中的表达呈强阳性；CD68免疫阳性细胞在外膜、中膜和内膜均可见到；CD31免疫阳性细胞不仅出现在血管腔内皮细胞和外膜小血管内皮细胞，且在中膜小血管内皮细胞也大量出现。免疫双重染色显示内皮细胞和巨噬细胞均表达MCP-1。结论：人静脉移植物MCP-1的表达上调，且和巨噬细胞的浸润关系密切，提示MCP-l对静物移植物炎症细胞的浸润及新内膜的形成有非常重要的作用。     

Distribution of human colonic dendritic cells and macrophages

To define the phenotype of intestinal dendritic cells and macrophages, resected colonic specimens were used to obtain lamina propria cell suspensions by EDTA treatment, then enzymatic digestion. The phenotype of dendritic cell-enriched suspensions was compared with that of macrophage-enriched populations by immunocytochemistry using the avidin-biotin-peroxidase (ABC) system and immunoelectron microscopy. Dendritic cells expressed HLA-DR (L243) and HLA-DQ-associated (RFD1) antigens and CD68 in a perinuclear distribution. Staining for S100 was weak or absent. Macrophages also expressed HLA markers (L243 and RFD1) and CD68. The 25F9 antigen was expressed strongly, whilst CD14 was absent from cells isolated from non-inflamed tissues. To determine their anatomic distribution, immunohistochemistry was performed using single- and double-labelling techniques (ABC ± alkaline phosphatase anti-alkaline phosphatase method). Mutually exclusive subsets of 25F9⁺ and S100⁺cells were seen: 25F9⁺ macrophages were concentrated in a band immediately beneath the luminal epithelium; S100⁺/HLA-DR⁺ dendritic cells formed a reticular network throughout the lamina propria and beneath the basement membrane of the crypts. This distribution suggests that macrophages may help regulate intestinal responses by acting as the first line of defence against the entry of luminal antigens. A breach of the macrophage ‘barrier’ by invading antigens may necessitate the recruitment of T cell responses by immunostimulatory dendritic cells.     

Comparative analysis of the interaction of Helicobacter pylori with human dendritic cells, macrophages, and monocytes

Helicobacter pylori may cause chronic gastritis, gastric cancer, or lymphoma. Myeloid antigen-presenting cells (APCs) are most likely involved in the induction and expression of the underlying inflammatory responses. To study the interaction of human APC subsets with H. pylori, we infected monocytes, monocyte-derived dendritic cells (DCs), and monocyte-derived (classically activated; M1) macrophages with H. pylori and analyzed phenotypic alterations, cytokine secretion, phagocytosis, and immunostimulation. Since we detected CD163(+) (alternatively activated; M2) macrophages in gastric biopsy specimens from H. pylori-positive patients, we also included monocyte-derived M2 macrophages in the study. Upon H. pylori infection, monocytes secreted interleukin-1β (IL-1β), IL-6, IL-10, and IL-12p40 (partially secreted as IL-23) but not IL-12p70. Infected DCs became activated, as shown by the enhanced expression of CD25, CD80, CD83, PDL-1, and CCR7, and secreted IL-1β, IL-6, IL-10, IL-12p40, IL-12p70, and IL-23. However, infection led to significantly downregulated CD209 and suppressed the constitutive secretion of macrophage migration inhibitory factor (MIF). H. pylori-infected M1 macrophages upregulated CD14 and CD32, downregulated CD11b and HLA-DR, and secreted mainly IL-1β, IL-6, IL-10, IL-12p40, and IL-23. Activation of DCs and M1 macrophages correlated with increased capacity to induce T-cell proliferation and decreased phagocytosis of dextran. M2 macrophages upregulated CD14 and CD206 and secreted IL-10 but produced less of the proinflammatory cytokines than M1 macrophages. Thus, H. pylori affects the functions of human APC subsets differently, which may influence the course and the outcome of H. pylori infection. The suppression of MIF in DCs constitutes a novel immune evasion mechanism exploited by H. pylori.     

Cat allergen induces proinflammatory responses by human monocyte-derived macrophages but not by dendritic cells

BACKGROUND: The upper airway mucosa of healthy humans contains a dense network of cells with dendritic morphology of which the majority express a macrophage-like phenotype (CD14+CD64+CD68+), whereas the smaller population are immature dendritic cells (DC; CD11c+CD14-). Our aim was to study the proinflammatory response of human monocytes and in vitro-generated macrophages and DC after contact with cat allergens. METHODS: Monocyte-derived DC and monocyte-derived macrophages were exposed to cat allergen extract or Escherichia coli. Purified monocytes were stimulated with allergen extracts from cat or house dust mite (HDM) or the major allergenic protein Fel d 1 and induction of proinflammatory cytokines by monocytes was analyzed before and after blocking CD14. RESULTS: We show that cat allergen extract induced tumor necrosis factor (TNF) and interleukin (IL)-6 production by CD14-positive macrophages but not by CD14-negative DC. Moreover, monocytes produced significantly higher levels of TNF in response to cat allergens than in response to HDM allergens. We observed no differences in levels of TNF and IL-6 from either macrophages or monocytes after exposure to cat allergen when comparing healthy and cat-allergic individuals. Finally, the proinflammatory cytokine production from monocytes in response to cat allergen extract but not to HDM allergen was significantly reduced by blocking CD14. CONCLUSION: These results indicate that closely related innate immune cells from the myeloid lineage respond differentially to cat allergen extract and that the pattern-recognition receptor CD14 might be one of the mediators involved in the inflammatory responses to inhalant allergens.     

SARS-coronavirus replication in human peripheral monocytes/macrophages

A novel coronavirus (CoV) has been described in association with cases of severe acute respiratory syndrome (SARS). The virus, SARS-CoV, differs from the previously described human coronaviruses, 229E and OC43. 229E was previously shown to productively infect human monocytes/macrophages, whereas OC43 poorly infected the cells. In this study, we examined whether SARS-CoV could productively infect purified monocytes/macrophages (PM) derived from human donor cells. Unlike 229E-infected cells, which produced viral titers of 10(3.5) to 10(6)TCID50/ml, SARS-CoV replicated poorly in PM, producing titers of 10(1.75) to 10(2)TCID50/ml. This finding was similar to results reported for OC43-infected cells, with titers ranging from 10(1.2) to 10(2.7)TCID50/ml. Of interest, SARS-CoV proteins were detected only in PM that did not produce significant amounts of interferon (IFN)-alpha, and in one such case, preliminary electron microscope studies demonstrated that SARS-CoV-like particles could enter the cells, possibly via phagocytosis. These results suggest that SARS-CoV, like human CoV OC43, poorly infects human PM, and production of IFN-alpha by these cells further limits the infection. Given the importance of monocytes/macrophages to the immune response, it is possible that their infection by SARS-CoV and alteration of this infection by IFN-alpha may be important to the course of the infection in humans.