Differential expression of the chemokine receptors CX3CR1 and CCR1 by microglia and macrophages in myelin-oligodendrocyte-glycoprotein-induced experimental autoimmune encephalomyelitis

Chemokines are important for the recruitment of immune cells into sites of inflammation. To better understand their functional roles during inflammation we have here studied the in vivo expression of receptors for the chemokines CCL3/CCL5/CCL7 (MIP-1alpha/RANTES/MCP-3) and CX3CL1 (fractalkine), CCR1 and CX3CR1, respectively, in rat myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis. Combined in situ hybridization and immunohistochemistry demonstrated intensely upregulated CCR1 mRNA expression in early, actively demyelinating plaques, whereas CX3CR1 displayed a more generalized expression pattern. CX3CR1 mRNA expressing cells were identified as microglia on the basis of their cellular morphology and positive GSA/B4 lectin staining. In contrast, CCR1 mRNA was preferentially expressed by ED1+ GSA/B4+ macrophages. The notion of differential chemokine receptor expression in microglia and monocyte-derived macrophages was corroborated at the protein level by extraction and flow cytometric sorting of cells infiltrating the spinal cord using gating for the surface markers CD45, ED-2 and CD11b. These observations suggest a differential receptor expression between microglia and monocyte-derived macrophages and that mainly the latter cell type is responsible for active demyelination. This has great relevance for the possibility of therapeutic intervention in demyelinating diseases such as multiple sclerosis, for example by targeting signaling events leading to monocyte recruitment.     

IL-12基因不同亚基真核表达载体的构建及表达

目的:克隆并构建含人白介素12(hIL-12)基因p35、p40不同亚基的真核表达载体,瞬时转染真核细胞并诱导IL-12的表达。方法:人单核细胞白血病细胞株(THP-1)和人白血病细胞株(HL-60),经DMSO、IFN-γ和LPS诱导后,用RT-PCR及SOEPCR扩增IL-12p40、p35及p40-p35融合基因;并构建pcDNA-p35、pcDNA-p40及pcDNA-IL-12真核表达载体。以3种重组质粒分别瞬时转染COS-7细胞后,通过RT-PCR及ELISA法检测目的基因的表达。结果:经诱导后,从HL-60细胞中扩增到IL-12p40和p35基因片段;但从THP-1细胞中只扩增到p35基因片段,未能扩增到p40基因片段;经酶切鉴定、PCR扩增及序列测定表明pcDNA-p35、pcDNA-p40及pcDNA-IL-12真核表达质粒构建成功;并在COS-7细胞中可检测到IL-12的表达。结论:含hIL-12基因不同亚基的真核表达质粒的成功构建,对进一步研究IL-12在免疫应答中的调节作用以及作为免疫佐剂改善BCG免疫保护效果的研究奠定了基础。     

结核分枝杆菌Ag85B与IL-12基因真核共表达质粒的构建及表达

目的 :构建结核分枝杆菌Ag85B和鼠IL 12基因的共表达载体pBud85B IL12。方法 :将结核分枝杆菌Ag85B基因和鼠IL 12基因同时克隆入含多启动子的共表达载体pBudCE4 .1中 ,构建真核共表达质粒pBud85B IL12。以pBud85B IL12转染COS 7细胞 ,通过RT PCR及ELISA方法检测目的基因的表达。结果 :在COS 7细胞中同时可检测到Ag85B和IL12的表达。结论 :pBud85B IL12共表达质粒的成功构建 ,为对其免疫原性、免疫反应性及免疫保护作用的进一步研究奠定了基础     

hdll1ext-Fc融合蛋白真核表达载体的构建及表达

目的：构建人dlll^ext(human delta-likel extraeellular region)-Fe融合蛋白的真核表达载体pEF-BOSneo-hdlll^ext-Fc，并在COS-7细胞中进行表达。方法：从人脑cDNA文库中PCR扩增人delta-likel胞外段，通过DNA重组构建真核表达载体pEF-BOSneo-hdlll^ext-Fe。瞬时转染COS-7细胞，应用RT-PCR、细胞免疫荧光技术和双抗体夹心ELISA，检测融合蛋白的表达。结果：成功地构建了真核表达载体pEF-BOSneo-hdlll^ext-Fc。以重组载体转染COS-7细胞后，RT-PCR结果显示delta-likel胞外段与IgG1 Fe在mRNA水平正确拼接；细胞免疫荧光染色呈阳性反应；夹心ELISA法检测到细胞培养上清中有融合蛋白的表达。结论：成功地扩增了人delta-likel胞外段，构建了pEF-BOSneo-hdlll^ext-Fc真核表达载体，并在COS-7细胞中获得表达，为下一步研究奠定了基础。     

hdll1~(ext)-Fc融合蛋白真核表达载体的构建及表达

目的 :构建人dll1ext(humandelta like1extracellularregion) Fc融合蛋白的真核表达载体pEF BOSneo hdll1ext Fc,并在COS 7细胞中进行表达。方法 :从人脑cDNA文库中PCR扩增人delta like1胞外段 ,通过DNA重组构建真核表达载体 pEF BOSneo hdll1ext Fc。瞬时转染COS 7细胞 ,应用RT PCR、细胞免疫荧光技术和双抗体夹心ELISA ,检测融合蛋白的表达。结果 :成功地构建了真核表达载体 pEF BOSneo hdll1ext Fc。以重组载体转染COS 7细胞后 ,RT PCR结果显示delta like1胞外段与IgG1Fc在mRNA水平正确拼接 ;细胞免疫荧光染色呈阳性反应 ;夹心ELISA法检测到细胞培养上清中有融合蛋白的表达。结论 :成功地扩增了人delta like1胞外段 ,构建了 pEF BOSneo hdll1ext Fc真核表达载体 ,并在COS 7细胞中获得表达 ,为下一步研究奠定了基础     

Expression of chemokine receptors CXCR4, CCR2, CCR5 and CX3CR1 in neural progenitor cells isolated from the subventricular zone of the adult rat brain

We have studied the expression of chemokine receptors CXCR4, CCR2, CCR5, and CX3CR1 at the mRNA and protein levels in adult neural progenitor cells (NPCs) in neurosphere cultures using RT-PCR and immunocytochemistry methods. NPCs were isolated from the subventricular zone of adult rat brain and propagated in vitro as neurospheres. The neurospheres showed immunoactivity of nestin, an intermediate filament marker for NPCs. NPCs in the neurosphere cultures differentiated into NeuN-, GFAP-, or GalC-positive cells in vitro. Using cultured cortical microglial cells as positive control, we demonstrated the mRNA expression of CXCR4, CCR2, CCR5, and CX3CR1 in neurospheres by RT-PCR. Double immunofluorescent staining further confirmed the co-localization of nestin with either CXCR4, CCR2, CCR5, or CX3CR1 on neurospheres. These results suggest that adult NPCs in the neurosphere cultures express chemokine receptors CXCR4, CCR2, CCR5, and CX3CR1.     

Cysteinyl leukotrienes induce monocyte chemoattractant protein 1 in human monocytes/macrophages

BACKGROUND: Monocytes/macrophages have a cysteinyl leukotriene 1 (CysLT1) receptor, but its function is poorly understood. Objective To elucidate the biological function of the CysLT1 receptor of human monocytes/macrophages. METHODS: We examined the production of TNF-alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, monocyte chemoattractant protein 1 (MCP-1), macrophage colony-stimulating factor (M-CSF), and eotaxin induced by CysLTs (leukotriene (LT)C4, -D4, and -E4) in THP-1 cells, a human monocytic leukaemia cell line, and peripheral blood CD14+ monocytes/macrophages. Moreover, we examined the effect of CysLTs on the expression of beta-chemokine receptor 2B (CCR2B) as the receptor of MCP-1 by Western blot analysis. RESULTS: ELISA revealed that CysLTs induced MCP-1 in THP-1 cells and peripheral blood CD14+ monocytes/macrophages, but not other cytokines. PCR demonstrated that CysLTs increased MCP-1 mRNA expression in THP-1 cells, and Western blotting showed that CysLTs increased the expression of CCR2B in THP-1 cells. Moreover, we demonstrated that pranlukast, a CysLT1 receptor antagonist, blocked MCP-1 production by CysLTs in THP-1 cells almost completely, and partially inhibited MCP-1 release by CysLTs in peripheral blood CD14+ monocytes/macrophages and CCR2B expression by CysLTs in THP-1 cells. CONCLUSION: CysLTs induce MCP-1 and increase CCR2B expression in human monocytes/macrophages.     

IL-13及其变异体真核表达载体的构建表达与亚细胞定位

目的：体外构建野生型人白细胞介素-13（whIL-13）及变异型人白细胞介素-13（mhIL-13）与增强型绿色荧光蛋白（EGFP）融和蛋白真核表达载体，分析其在COS-7细胞中的表达和亚细胞定位。方法：以RT-PCR方法扩增whIL-13、mhIL-13全长编码基因，构建EGFP-whIL-13、EGFP-mhIL-13融和蛋白真核表达载体，转染COS-7细胞，以激光扫描共聚焦显微镜观察融合蛋白的表达及其在细胞内的分布情况。结果：两种融和蛋白表达载体均构建正确，将其转染COS-7细胞后，在阳性克隆胞浆内均可见明亮的绿色荧光，胞核空虚。结论：成功构建EGFP-whIL-13、EGFP-mhIL-13融和蛋白表达载体，并在COS-7细胞中得到表达，表达的两种融和蛋白细胞内分布特征没有区别，均位于胞浆内。     

RNAi沉默NF-κB p65对小鼠巨噬细胞细胞因子表达的影响

目的: 探讨RNA干扰(RNAi)技术在抑制NF-κB p65表达、调控LPS活化后巨噬细胞细胞因子表达中的应用。方法: 利用阳离子脂质体将NF-κB p65小干扰RNA(siRNA)瞬时转染入Ana-1细胞,RT-PCR及Western blotting法检测其沉默效率,ELISA法检测LPS(1 mg/L)刺激下0 h、4 h、12 h和24 h Ana-1细胞培养上清中TNF-α、IL-1β、IL-6和IL-10浓度。结果: NF-κB p65 siRNA转染24 h后,NF-κB p65在基因水平及蛋白水平表达均被明显抑制(P<0.05)。RNA干扰组Ana-1细胞培养上清中细胞因子TNF-α、IL-1β和IL-6表达在相应时点内均较对照组明显降低(P<0.05),IL-10表达显著升高,在12 h和24 h差异显著(P<0.05)。结论: 体外实验初步证实RNAi技术能有效沉默小鼠巨噬细胞NF-κB p65 基因的表达,下调其下游调控的促炎症细胞因子TNF-α、IL-1β、IL-6及上调抑炎症细胞因子IL-10的表达,从而抑制过度的炎症反应。     

SIGIRR-EGFP真核表达载体构建及在H292细胞中的亚细胞定位研究

目的 通过增强型绿色荧光蛋向示踪技术,观察SIGIRR(single Ig IL,1R-related molecule)在人气道上皮细胞株H292中的分布特点及对上皮细胞天然免疫功能的影响.方法 构建SIGIRR-EGFP融和蛋白的真核表达载体,运用脂质体转染的方法转染人气道上皮细胞株H292,再利用激光共聚焦显微镜对其进行亚细胞定位研究.经LPS刺激后,ELISA检测转染前 后上皮细胞TNF-α分泌水平的差异.结果 构建的融和蛋白表达载体SIGIRR-EGFP经EooR Ⅰ和BamH Ⅰ双酶切后,电泳显 示其条带大小为4.7 kh和1.23 kb左右,经测序证实SIGIRR的序列与GenBank公布的人cDNA序列完全一致.激光共聚焦显示pEGFP-N1空载体转染表达的绿色荧光蛋白在H292细胞中均匀分布,而重组载体SIGIRR-ECFP表达的融和蛋白在H292细胞核周(膜)和细胞膜边缘上有连续分布现象.经LPS刺激后,pEGFP-N1转染的细胞和未转染细胞TNF-α水平无显著性差异(P＞0.05),而SIGIRR-EGFP转染细胞与pEGFP-N1转染细胞相比,显著降低了TNF-α的产生(P＜0.01).结论 成功构建了SI-GIRR-EGFP融和蛋白的真核表达载体,并利用绿色荧光蛋白标记的方法显示了SIGIRR分子在H292细胞中细胞膜分布.过表达的SIGIRR降低了上皮细胞IPS诱导的炎症因子TNF-α产生.     

Infection of human primary hepatocytes with dengue virus serotype 2

While the impact of the dengue viruses on liver function is prominent as shown by hepatomegaly, liver enzyme abnormality, occasional fulminant hepatic failure and histological changes including hepatocellular necrosis, significant debate exists as to the possible involvement of the predominant cell type in the liver, hepatocytes, in the disease process. To address this issue purified human primary hepatocytes were exposed to dengue virus serotype 2 and the production of de novo viral progeny was established by standard plaque assay, RT-PCR and immunocytochemistry. To investigate the response of the primary hepatocytes to infection, the expression of a panel of 9 cytokine genes (IFN-beta, TRAIL, MCP-1, IL-6, IL-1beta, IL-8, MIP-1alpha, MIP-1beta, and RANTES) was semi-quantitatively investigated by RT-PCR and up-regulation of TRAIL, MIP-1alpha, IFN-beta, MIP-1beta, IL-8, and RANTES was observed in response to infection. The induction of IL-8 in response to infection was accompanied by the secretion of IL-8 as verified by ELISA assay. The ability of hepatocytes to be infected with dengue virus serotype 2 in vitro support evidence implicating human hepatocytes as a target cell in cases of dengue virus infection, and provide the first experimental evidence to support the large number of clinical studies that implicate the liver as a critical target organ in severe cases of dengue infection.     

人β2微球蛋白基因启动子的克隆及其在P815细胞中的活性研究

目的:克隆人β2微球蛋白(β2m)基因启动子,并研究其在小鼠肥大细胞瘤细胞P815中对下游报告基因的启动活性。方法:用PCR法从基因组内扩增β2m基因启动子。通过基因重组的方法,构建含此启动子的EGFP基因真核表达载体,然后分别瞬时和稳定转染P815细胞。通过RT-PCR、荧光显微镜摄像和流式细胞术分析,观察IFN-γ作用前后EGFP的表达。结果:从基因组内扩增出302bp的人β2m基因的启动子,成功地构建了含此启动子的真核报告载体。RT-PCR的结果表明,IFN-γ对启动子的活性具有诱导作用,且呈浓度依赖性。流式细胞术的结果显示,在5×105U/LIFN-γ作用下,尽管表达EGFP的细胞数量没有差异,但刺激组EGFP的表达强度是未刺激组的2倍。结论:人β2m基因启动子在小鼠肥大细胞瘤细胞P815中具有高度的启动活性。通过该启动子中所含干扰素刺激反应元件(ISRE),可在IFN-γ诱导作用下调控下游目的基因的表达。     

Parvovirus B19 nonstructural (NS1) protein as a transactivator of interleukin‐6 synthesis: Common pathway in inflammatory sequelae of human parvovirus infections?

This review focuses on the role that human parvovirus B19 nonstructural (NS1) protein as a transactivator of the proinflammatory cytokine, interleukin-6 (IL-6), might play in triggering the multiparametric inflammatory outcomes of B19 infection. Parvovirus B19 is a ubiquitous virus, and it is often expressed during conditions of immunodepression including that induced by long-term chemotherapy, viral infection (HIV, HTLV-1), or genetic immunodeficiency disorders. Through NS1 expression, B19 may contribute to the immune dysregulation associated with these disorders, or serve as a cofactor in enhancing retroviral replication. Hence, NS1 transactivation of proinflammatory cytokine promoters such as IL-6 may be pivotal in triggering the various inflammatory and autoimmune disorders that have been linked to parvovirus B19 infections.     

Adenoviral interleukin-12 gene transduction into human bronchial epithelial cells: up-regulation of pro-inflammatory cytokines and its prevention by corticosteroids

BACKGROUND: One of the potential effects of IL-12 is to restore Th1/Th2 balance. Therefore, we investigated the possibility of developing a system for local delivery of IL-12 into the airways by examining protein expression in a human bronchial epithelial cell line (BEAS-2B) after adenoviral IL-12 gene transduction. The effects of dexamethasone on the gene-modified cells were also examined. MEHODS: Adenoviral vectors AxCAegfp and Ax1CIhp40ip35 were used to transduce enhanced green fluorescence protein and IL-12 genes, respectively, into BEAS-2B cells. Wild-type and IL-12 gene-transduced BEAS-2B cells were then incubated with or without dexamethasone, and concentrations of IL-12, IFN-gamma, IL-6, IL-8, granulocyte macrophage-colony stimulating factor and chemokines (TARC and RANTES) in the supernatant were measured by ELISA. IL-12 receptor expression was analysed by flow cytometry and RT-PCR. RESULTS: The efficiency of transgene expression in BEAS-2B cells at a multiplicity of infection of 30 was approximately 80%. Gene-modified BEAS-2B cells produced biologically active IL-12, regardless of dexamethasone treatment. While IL-12 gene transduction led to increased production of IL-6 and IL-8 by BEAS-2B cells, expressions of these proteins were suppressed by dexamethasone. Addition of exogenous IL-12 failed to augment BEAS-2B cell IL-6 and IL-8 production, and IL-12 receptor expression by BEAS-2B cells was not detected. CONCLUSIONS: Our findings suggest that adenoviral IL-12 gene transduction may be effective in inducing IL-12 expression in the airways, and could be a potential approach in the management of bronchial asthma.     

人IL-18结合蛋白AcDNA的克隆及在COS-7细胞中的表达

目的：克隆人IL－18结合蛋白（hIL-18BPa)的cDNA，观察其在COS－7的表达。方法：采用RT－PCR自人白血病细胞株jukat中获得hIL-18 BPa的cDNA，将其克隆至T－vector中，经测序确证后，将该基因定向插入真核表达载体pcDNA3.1( )中，脂质体介导法将其转染COS－7细胞，72h后收集上清纯化，用BCA法测定hIL-18 BPa的含量，用ELISA法测定其活性。结论：获得的IL－18BPa的cDNA序列gene bank登录的cDNA序列一致。上清液中hIL-18BPa含量为1．4mg/L，并具有良好的生物学活性。结论：成功克隆hIL-18 BPa基因，并实现了COS－7细胞中的瞬时表达，为研究其活性奠定了基础。