GM—CSF在登革病毒感染人单核细胞中的作用

以正常人外周血和脐带血单核细胞作为登革Ⅱ型病毒（Ｄ２Ｖ）感染的靶细胞，研究了粒细胞巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）对Ｄ２Ｖ复制的影响以及单核细胞感染Ｄ２Ｖ后ＧＭ－ＣＳＦ产生能力的变化。结果表明，ＧＭ－ＣＳＦ能增加Ｄ２Ｖ的复制，Ｄ２Ｖ感染能引起人单核细胞产生ＧＭ－ＣＳＦ，它们的量与Ｄ２Ｖ感染量呈正相关。结果提示，ＧＭ－ＣＳＦ在病毒感染过程中起重要作用。     

IL-6与登革病毒感染相互关系的实验研究

目的：研究ＩＬ－６对登革Ⅱ型病毒（Ｄ２Ｖ）复制的影响以及细胞感染Ｄ２Ｖ后ＩＬ－６产生能力的变化。方法：以人单核细胞为感染模型，用微量蚀斑法测定病毒滴度，用ＥＬＩＳＡ法测定ＩＬ－６含量。结果：重组ＩＬ－６能增强Ｄ２Ｖ的复制，Ｄ２Ｖ感染能引起人单核细胞产生ＩＬ－６，它们的水平与Ｄ２Ｖ感染量正相关。结论：ＩＬ－２在登革病毒感染中起重要的作用。     

小鼠抗登革病毒2型单克隆抗体的制备及鉴定

目的 制备小鼠抗登革病毒2型(TR1751株)的单克隆抗体(Monoclonal antibody mAb)，并对其性质进行鉴定。方法免疫原为病毒感染的Blabfc乳鼠脑组织，匀浆后离心，去除细胞成分。免疫Blab／c小鼠，将小鼠脾细胞和SP2／0细胞融合后，通过ELISA、间接免疫荧光染色、噬斑减少中和实验(Plaque reduction neutralization test，PRNT)及Western blot进行筛选和鉴定。结果筛选到I1、I9和B152 3株杂交瘤细胞系，其分泌的mAb均为识别登革病毒E蛋白的中和抗体。结论获得了3株分泌小鼠抗登革病毒2型mAb的杂交瘤细胞系，利用所制备的抗体，为进一步研究登革病毒致病机理和开发疫苗提供了免疫学工具。     

Antiviral activity of carbohydrate-binding agents and the role of DC-SIGN in dengue virus infection

Dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) is an important binding receptor for dengue virus (DENV) that recognizes N-glycosylation sites on the viral E-glycoprotein. DENV cannot bind nor infect the human B-cell line Raji/0. However, DENV productively infects Raji/DC-SIGN⁺ cells that constitutively express DC-SIGN on their surface. IL-4-treated monocytes, expressing high levels of DC-SIGN, are also susceptible for DENV infection. Several carbohydrate-binding agents (CBAs), such as the plant lectins HHA, GNA (mannose-specific) and UDA (N-acetylglucosamine-specific), inhibited dose-dependently the binding of DENV and subsequently viral replication in Raji/DC-SIGN⁺ cells (EC₅₀: 0.1-2.2 μM). These CBAs were clearly more active against DENV in IL-4-treated monocytes (EC₅₀: 4-56 nM). However, the CBAs were devoid of antiviral activity in DENV-susceptible Vero-B (DC-SIGN⁻) cells, demonstrating cell type-dependent differences in viral entry mechanisms.     

Phagocytosis of Leishmania donovani amastigotes is Rac1 dependent and occurs in the absence of NADPH oxidase activation

Macrophages produce little superoxide during phagocytosis of Leishmania donovani amastigotes. In this study, we characterized molecular events associated with L. donovani amastigotes uptake by mouse macrophages, to further define the mechanisms by which they are internalized without triggering superoxide production. Using transient transfections, we first showed that internalization of L. donovani amastigotes is mediated by the GTPases Rac1 and Arf6, of which Rac1 is recruited and retained on parasite-containing phagosomes. Next, we showed that, whereas internalization of amastigotes induced no superoxide release, co-internalization of serum-opsonized zymozan and amastigotes resulted in superoxide production. Furthermore, in co-internalization experiments, we detected superoxide production in over 95% of phagosomes containing IgG-opsonized SRBC compared to 5% of amastigote-harboring phagosomes. These results suggest that amastigotes evade the ability of macrophages to produce superoxide during phagocytosis. Consistently, we observed that amastigotes induced barely detectable phosphorylation of the NADPH oxidase component p47phox, leading to a defective phagosomal recruitment of p67phox and p47phox. Finally, we showed that amastigotes disrupt phagosomal lipid raft integrity, potentially interfering with NADPH oxidase assembly. Collectively, our results indicate that internalization of L. donovani amastigotes is a Rac1- and Arf6-dependent process that occurs in the absence of significant NADPH oxidase activation.     

External quality control assessment in PCR diagnostics of dengue virus infections

BACKGROUND: Increased travelling to countries endemic for dengue fever (DF) demands efficient laboratory diagnostics. Nucleic acid amplification techniques (NAT) are now frequently used for rapid diagnosis of imported viral diseases. Different PCR systems are available. OBJECTIVES: In order to assess the quality of molecular diagnostics of dengue virus infections, an external quality assurance (EQA) in PCR diagnostics was conducted. Study design: A panel of 10 human plasma samples was prepared and spiked with dengue virus types DEN-1 to DEN-4. In addition, a 10-fold dilution series (1:10-1:10(4) ) of DEN-3 virus was included. The panel was pre-tested by nested RT-PCR, in-house real-time PCR, and a commercial real-time PCR kit. The samples were inactivated by gamma irradiation and shipped in freeze dried state. Thirteen laboratories, within the European network for the diagnostics of imported viral diseases (ENIVD) took part using either single-round, nested, or real-time RT-PCR methods. Two laboratories used two methods in parallel, summarising up to 15 comparable results. RESULTS: 33-100% correct results were achieved. All laboratories detected DEN-2 correctly, followed by DEN-1 (14 positive results of 15), DEN-3 (12/15) and DEN-4 (11/15). Testing of the serial dilution revealed low sensitivity in many labs, with results ranging from 33 to 80% of correctly tested samples. CONCLUSION: The EQA gives a feedback of the quality of the RT-PCR system used by each respective laboratory. The different test systems and amplification conditions demonstrate the importance of external quality control measures.     

两株登革2型病毒感染BALB/C小鼠特异性抗体产生动态的比较

目的：两株登革2型病毒(Dengue Type 2 virus，DV2)初次和再次感染BALB／C小鼠建立动物感染模型，对其产生特异性抗体进行动态观察，探讨感染DV2NGC株和DV2临床分离株(B株)引起的体液免疫应答的差异。方法：两株DV2毒株模拟自然感染途径，经皮下多点注射建立BALB／C小鼠感染动物模型；采用间接ELISA法检测感染动物血浆中抗DV2特异性IgM类抗体、IgG类抗体，并同时分离病毒观察病毒血症期的变化。结果：不同DV2毒株初次、再次感染BALB／C小鼠后诱导特异性Ig产生的类别存在差异，且Dv2B株再次感染动物后表现为病毒血症期相对延长。结论：两株DV2诱导特异性抗体产生的动态与病毒血症期不同。     

LIGHT is involved in the pathogenesis of rheumatoid arthritis by inducing the expression of pro-inflammatory cytokines and MMP-9 in macrophages

Macrophages play a crucial role in the perpetuation of inflammation and irreversible cartilage damage during the development of rheumatoid arthritis (RA). LIGHT (TNFSF14) and its receptor TR2 (TNFRSF14) are known to have pro-inflammatory activities in foam cells of atherosclerotic plaques. We tested a hypothesis that LIGHT and TR2 are involved in activation of monocyte/macrophages in RA synovium. Immunohistochemical analysis of RA synovial tissue samples revealed that both LIGHT and TR2 are expressed in CD68 positive macrophages. In contrast, synovial tissue samples from osteoarthritis (OA) patients failed to reveal the expression of LIGHT. Expression of TR2 in RA synovial macrophages was also detected using flow cytometry analysis. To identify the role of LIGHT in the functioning of macrophages in RA, we isolated macrophage enriched cells from RA synovial fluid and stimulated them with LIGHT. LIGHT induced expression of matrix metalloproteinase-9 and pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-8. These data indicate that LIGHT and TR2 expressed in macrophages are involved in the pathogenesis of RA by inducing the expression pro-inflammatory cytokines and matrix degrading enzymes.     

登革2型病毒43株NS1基因重组质粒DNA的免疫原性及保护作用研究

目的 研究以pcDNA3.1为载体的登革2型病毒43株（D2－43）NS1基因重组DNA的免疫原性及对登革病毒感染所致小鼠神经毒的免疫保护作用。方法 将纯化的pcDNA-NS1重组质粒DNA采用肌肉多点注射途径免疫3周龄BALB／c小鼠，剂量为每只100μg/次，检测了免疫鼠血清抗体滴度及特异性细胞毒作用。并以D2－43病毒脑内攻击6周龄BALB/c小鼠产生的神经毒症状为实验模型，对pcDNA-NS1的免疫保护作用进行了初步探讨。结果 用间接ELISA测得pcDNA-NS1免疫后抗体滴度为1：800，在补体存在下，对D2－43病毒感染的BHK－21细胞特异性杀伤率可达到61．6％。由免疫的BALB／c小鼠脾制备的效应细胞在体外可特异性地杀伤D2－43感染的P－815细胞（H－2^d)。当效靶比（E／T）为20：1时，pcDNA-NS1质粒免疫后的特异性CTL杀伤百分率为22．6％。将100 LD50的D2－43病毒经脑内攻击BALB／c小鼠，结果表明免疫pcDNA-NS1组小鼠存活率最高（90．9％）；与免疫pcDNA3.1对照组比较，P值＜0．05。结论 pcDNA-NS1质粒免疫BALB／c小鼠不仅可诱导体液免疫，还可诱导特异性细胞免疫。初步结果还显示，用含NS1基因的重组质粒DNA免疫的小鼠能免受致死剂量登革病毒的攻击，为登革热新型疫苗的研究奠定了基础。     

Macrophage activation governs schistosomiasis-induced inflammation and fibrosis

Macrophages regulate the initiation, maintenance, and resolution of chronic inflammatory responses and their function depends on their activation status. Studies in mice infected with the helminth parasite Schistosoma mansoni have been particularly helpful in defining the in vivo function of classically and alternatively activated macrophages (AAM?s). These studies have shown that AAM?s protect mice from acute and chronic S. mansoni infection through distinct mechanisms, which are discussed in this Viewpoint.     

Reciprocal regulation of IL‐23 and IL‐12 following co‐activation of Dectin‐1 and TLR signaling pathways

Recognition of microbial products by germ‐line‐encoded PRR initiates immune responses, but how PRR mediate specific host responses to infectious agents is poorly understood. We and others have proposed that specificity is achieved by collaborative responses mediated between different PRR. One such example comprises the fungal β‐glucan receptor Dectin‐1, which collaborates with TLR to induce TNF production. We show here that collaborative responses mediated by Dectin‐1 and TLR2 are more extensive than first appreciated, and result in enhanced IL‐23, IL‐6 and IL‐10 production in DC, while down‐regulating IL‐12 relative to the levels produced by TLR ligation alone. Such down‐regulation occurred with multiple MyD88‐coupled TLR, was dependent on signaling through Dectin‐1 and also occurred in macrophages. These findings explain how fungi can induce IL‐23 and IL‐6, while suppressing IL‐12, a combination which has previously been shown to contribute to the development of Th17 responses found during fungal infections. Furthermore, these data reveal how the collaboration of different PRR can tailor specific responses to infectious agents.     

Fetal-derived macrophages persist and sequentially maturate in ovaries after birth in mice

Macrophages, which are highly diverse in different tissues, play a complex and vital role in tissue development, homeostasis, and inflammation. The origin and heterogeneity of tissue-resident monocytes and macrophages in ovaries remains unknown. Here we identify three tissue-resident monocyte populations and five macrophage populations in the adult ovaries using high-dimensional single cell mass cytometry. Ontogenic analyses using cell fate mapping models and cell depletion experiments revealed the infiltration of ovaries by both yolk sac and fetal liver-derived macrophages already during the embryonic development. Moreover, we found that both embryonic and bone marrow-derived macrophages contribute to the distinct ovarian macrophage subpopulations in the adults. These assays also showed that fetal-derived MHC II-negative macrophages differentiate postnatally in the maturing ovary to MHC II-positive cells. Our analyses further unraveled that the developmentally distinct macrophage types share overlapping distribution and scavenging function in the ovaries under homeostatic conditions. In conclusion, we report here the first comprehensive analyses of ovarian monocytes and macrophages. In addition, we show that the mechanisms controlling monocyte immigration, the phenotype of different pools of interstitial macrophages, and the interconversion capacity of fetal-derived macrophages in ovaries are remarkably different from those seen in other tissue niches.     

温度对白纹伊蚊传播登革2型病毒易感性影响的研究

目的 研究不同温度下白纹伊蚊对登革病毒的易感性差异.方法 登革2型病毒人工经口感染白纹伊蚊,冻麻挑出吸饱血的雌蚊放入新的蚊笼,分别置于18℃、21℃、26℃、31℃、33℃和36℃的人工气候箱中饲养,经外潜伏期后,解剖蚊虫,间接免疫荧光法分别检测蚊虫的头部、唾液腺和胸腹部内的登革2型病毒抗原,并计算蚊虫的播散感染率.结果 18℃白纹伊蚊感染率最低,胸腹部感染率为8％,头部和唾液腺未检出.31℃胸腹部感染率最高为82％,头部和唾液腺感染率33℃时最高.36℃各部位感染率均较33℃下降.18℃的播散感染率最低为0,36℃播散感染率最高,达到了100％.结论 白纹伊蚊感染率随温度的升高,呈现先升后降趋势.18℃可能是白纹伊蚊传播登革病毒的最低温度.播散感染率随温度的升高逐渐升高.     

登革2型病毒ZSO1／01株E蛋白在真核细胞中的分泌表达研究

目的对登革2型病毒（DENV-2）ZSO1／01株E蛋白在哺乳动物细胞及昆虫细胞中的分泌表达进行研究。方法RT．PCR扩增DENV-2prM／E基因,通过融合PCR在prM基因前添加来自乙型脑炎病毒的信号肽序列,并将E基因羧基末端20％区域缺失或替换为乙型脑炎病毒SA14-2株E基因相应序列,将上述基因元件分别克隆人哺乳动物细胞表达载体pcDNA5／FRT及昆虫细胞表达载体pAcUW51-M中,将重组质粒转染293T细胞或Sf9细胞,利用间接免疫荧光（Immunofluoreseence assay,IFA）及Western Blot检测E蛋白的表达与分泌。结果各重组质粒分别转染293T细胞或Sit）细胞后,E蛋白在细胞内均有效表达,而仅有携带乙脑信号肽且缺失或替换E基因羧基末端20％区域的重组质粒转染293T细胞后,上清中可检测到明显的E蛋白分泌。结论信号肽及E基因羧基末端20％区域对登革病毒E蛋白的分泌至关重要,宿主细胞对其亦有一定影响。     

Early activation of natural killer and B cells in response to primary dengue virus infection in A/J mice

Dengue virus (DEN) causes the most prevalent arthropod-borne viral illness in humans worldwide. Immune mechanisms that are involved in protection and pathogenesis of DEN infection have not been fully elucidated due largely to the lack of an adequate animal model. Therefore, as a first step, we characterized the primary immune response in immunocompetent inbred A/J mice that were infected intravenously with a non-mouse-adapted DEN type 2 (DEN2) strain. A subset (55%) of infected mice developed paralysis by 14 days post-infection (p.i.), harbored infectious DEN in the central nervous system (CNS), and had an elevated hematocrit and a decreased white blood cell (WBC) count. Immunologic studies detected (i). increased numbers of CD69(+) splenic natural killer (NK) and B cells at day 3 p.i., (ii). DEN-specific IgM and IgG responses by days 3 and 7 p.i., respectively, and (iii). splenocyte production of IFNgamma at day 14 p.i. We conclude that the early activities of NK cells, B cells and IgM, and later actions of IFNgamma and IgG likely play a role in the defense against DEN infection.     

Galectin-9 plasma levels reflect adverse hematological and immunological features in acute dengue virus infection

BackgroundDengue virus (DENV) infection remains a major public health burden worldwide. Soluble mediators may play a critical role in the pathogenesis of acute DENV infection. Galectin-9 (Gal-9) is a soluble β-galactoside-binding lectin, with multiple immunoregulatory and inflammatory properties.ObjectiveTo investigate plasma Gal-9 levels as a biomarker for DENV infection.Study designWe enrolled 65 DENV infected patients during the 2010 epidemic in the Philippines and measured their plasma Gal-9 and cytokine/chemokine levels, DENV genotypes, and copy number during the critical and recovery phases of illness.ResultsDuring the critical phase, Gal-9 levels were significantly higher in DENV infected patients compared to healthy or those with non-dengue febrile illness. The highest Gal-9 levels were observed in dengue hemorrhagic fever (DHF) patients (DHF: 2464 pg/ml; dengue fever patients (DF): 1407 pg/ml; non-dengue febrile illness: 616 pg/ml; healthy: 196 pg/ml). In the recovery phase, Gal-9 levels significantly declined from peak levels in DF and DHF patients. Gal-9 levels tracked viral load, and were associated with multiple cytokines and chemokines (IL-1α, IL-8, IP-10, and VEGF), including monocyte frequencies and hematologic variables of coagulation. Further discriminant analyses showed that eotaxin, Gal-9, IFN-α2, and MCP-1 could detect 92% of DHF and 79.3% of DF, specifically (P < 0.01).ConclusionGal-9 appears to track DENV inflammatory responses, and therefore, it could serve as an important novel biomarker of acute DENV infection and disease severity.     

深圳市首例本地登革热3型病例的病原学检测与分析

目的对2016年深圳市报告的首例本地疑似登革热病例查明病因.分离鉴定病原体,从分子水平分析分离株的生物学特征.方法对疑似患者血清标本采用ELISA、胶体金免疫层析法和荧光RT-PCR方法分别检测登革病毒抗体、NS1抗原和病毒核酸,并用C6/36细胞分离登革病毒.采用RT-PCR方法扩增病毒PrM/M-E基因后进行序列测定,并与不同国家和地区的登革毒株进行同源性比较和进化树分析.结果从患者血清标本中检测到登革病毒IgM抗体、NS1抗原和登革3型病毒核酸,并成功分离到登革3型病毒,将其命名为DENV3-SZ1648.深圳市登革3型病毒分离株SZ1648与登革3型国际标准株H87株、国内外流行株80-2、GWL-25株在PrM/M-E基因上核苷酸同源性分别为92.0％、91.8％和90.3％,而与登革1、2、4型国际标准株HAWAII、NGC、H241同源性分别为68.7％、64.2％和63.2％.进化树显示SZ1648株与2007年印度尼西亚分离株MKS-0098亲缘关系最近,在进化树的同一分支上,和85-159株(Indonedia 1985)、2167株(Tahiti 1989)、29472株(Fiji1992)等同属基因Ⅰ亚型.患者发病前1个月在深圳居住,无输血史、无外出史.结论从病原学、血清学和分子生物学特征上均证实该本地病例是由登革3型病毒引起,这也是深圳市首次报道存在本地登革3型病毒的疫情,该毒株最有可能来源于印度尼西亚.     

贵州独山、兴义不明原因发热病人登革病毒的分离和鉴定的初步研究

目的 对贵州独山、兴义两地夏秋季不明原因发热病人血清进行登革病毒(DEN)分离及鉴定,从病原学角度证实贵州省人群DEN的感染情况.方法 于2005年6至10月份收集贵州独山县、兴义市两地不明原因发热病人血清356份,并接种于生长良好的单层C6/36细胞盲传3代,观察细胞病变,用抗DEN1～4型单克隆抗体通过间接免疫荧光法进行型别鉴定;用DEN NSl基因区特异性通用引物进行RT-PCR检测分离的DEN毒株核酸,经序列测定并作系统发生树分析.结果 3份病人血清标本可使C6/36发生细胞病变,用单克隆抗体、RT-PCR扩增和序列测定,鉴定为DEN2;系统发生树分析证明,分离的病毒与DEN2-43、DEN2-44株系统进化关系最近.结论 贵州省独山、兴义两地人群中存在DEN感染.     

Triggering of DC migration by dengue virus stimulation of COX‐2‐dependent signaling cascades in vitro highlights the significance of these cascades beyond inflammation

A term “bone‐breaking fever” is used in Chinese medicine to describe the symptoms of patients infected with dengue virus (DV). We examined the significance of the COX‐prostaglandin pathway in human DC infected by DV. We show that DV infection induced the expression of COX‐2 and the production of prostaglandin E₂ (PGE₂) in DC, and stimulated the DNA binding of NF‐κB and the kinase activity of both IκBα kinase (IKK) α and β. DV infection also activated MAPK and AP‐1 signaling. Both IκBα kinase‐NF‐κB and MAPK‐AP‐1 were upstream of COX‐2 activation. Our investigation into the significance of COX‐2‐PGE₂ pathway also revealed that DV infection enhances DC migration by inducing CC chemokine receptor 7 (CCR7) expression, and that blocking COX‐2 or MAPK activity suppresses DV‐induced DC migration. Our data also suggest that PGE₂ can induce CCR7 expression on DC and that antagonists of the PGE₂ receptors EP2 and EP4 suppress DV‐induced DC migration. We further show that the increased CCR7 expression was observed in both DV‐infected and bystander DC, suggesting the presence of secondary effects in inducing CCR7 expression. Collectively, this study reveals not only the pathways involved in COX‐2 synthesis in DV‐infected DC but also the autocrine action of PGE₂ on the migration of DV‐infected DC.     

登革病毒悬液芯片分型检测方法的建立

目的 建立一种基于悬液芯片的登革病毒(dengue virus,DV)检测方法,可对四种血清型登革病毒进行快速检测和鉴定.方法 依据GenBank上4种病毒的基因序列信息,设计并合成相关引物及探针序列.抽提病毒RNA,经反转录后对目的基因进行PCR扩增,产物与核酸探针微球组杂交后于Bio-PlexTM 200系统检测荧光信号值.结果 DV1的悬液芯片检测敏感性约9 DNA拷贝,DV2、DV3、DV4的悬液芯片检测敏感性约90 DNA拷贝.进而将本方法用于检测15份临床标本,其检测结果与分型荧光RT-PCR一致.结论 建立了可同时检测四种血清型登革病毒的悬液芯片检测方法,为快速筛查和鉴定登革病毒提供了新的手段.