Evidence for existence of a close association between CD14 and CXCR4 on monocytic cell line U937

The surface expression of HIV-1 coreceptors (CXCR4 and CCR5) on monocytes can be regulated by the ligand of CD14,and the susceptibility of the cells to HIV-1 is then changed.Our previous study found that monoclonal antibody against CD14 could dramatically inhibit CXCR4-mediated chemotaxis and cell-cell fusion.Based on these studies,we explored potential relationship between CD14 and CXCR4 on monocytic cell line U937.Flow cytometry analysis showed that anti-CXCR4 monoclonal antibody (mAb) 12G5 strongly inhibited binding of the FITC-conjugated anti-CD14 monoclonal antibodies (TUK4 and UCHM1) to U937,while another CX- CR4-specific mAb B-R24 did not show any effect on this binding.On the other hand,two anti-CD14 monoclonal antibodies (TUK4 and UCH-M1) obviously inhibited the binding of the PE-conjugated anti-CXCR4 mAb 12G5 to U937 but did not inhibit the binding of mAb 12G5 to CXCR4-transfected 3T3 cells (3T3.T4.CXCR4),which indicates that the blocking of mAb 12G5 binding to CXCR4 by CD14- specific mAbs is not involved in the possibility that CD14-specific mAbs directly bind to CXCR4.These results suggested existence of a close association between CD14 and CXCR4 on monocytic cell line U937.     

Effects of PKCαantisense RNA on human breast cancer cell proliferation and expression of cyclinDl and CDK4

The role of PKCα in human breast cancer cell proliferation and expression of cyclinD1 and CDK4 has been investigated using inhibition of PKCα expression by its antisense RNA. When PKCα expression was inhibited the rate of cell proliferation decreased apparently and the levels of cyclinD1 and CDK4 mRNA were lower than the control. The results showed that PKCα, a key member of signal transduction system, played an important role in human breast cancer cell proliferation and had a close relationship with expression of cyclinD1 and CDK4 which control start of cell cycle.     

Protein Subcellular Localization Prediction and Genomic Polymorphism Analysis of the SARS Coronaviru

The cause of severe acute respiratory syndrome (SARS) has been identified as a new coronavirus (CoV). Several sequences of the complete genome of SARS-CoV have been determined. The subcellular localization (SubLocation) of annotated open-reading frames of the SARS-CoV genome was predicted using a support vector machine. Several gene products were predicted to locate in the Golgi body and cell nucleus. The SubLocation information was combined with predicted transmembrane information to develop a model of the viral life cycle. The results show that this information can be used to predict the functions of genes and even the virus pathogenesis. In addition, the entire SARS viral genome sequences currentlyav ailable in GenBank were compared to identify the sequence variations among different isolates. Some variations in the Hong Kong strains may be related to the special clinical manifestations and provide clues for understanding the relationship between gene functions and evolution. These variations reflect the evolution of the SARS virus in human populations and may help development of a vaccine.     

Cell adhesion receptors and cancer

Cell-to-cell and cell-to-extracellular matrix (ECM) interactions in the functions of cell adhesion and signal transduction are important in global control of cell phenotypes and cell behavior and are crucial for maintenance of homeostasis and structural/functional stabilization of tissues and organs. Cell adhesion receptors are recognized as the molecular basis of cell adhesion. Cadherin and Integrin are widely expressed adhesion receptors in most tissues. They are transmembrane glycoproteins which, through their cytoplasmic domain, bind to many proteins at the inner surface of cell membrane to form molecule-linkage complexes and then connect with the cytoskeleton. Through cell adhesion receptors a network functioning as cell adhesion and signal transduction is organized between tissue cells and cell-ECM. In this regard cell adhesion receptors play an important role in regulation of morphogenesis, cell-cell recognition, cell migration, cell sorting and the determination of cell's fate in development. They mediate cell functions and their fault expression is intimately correlated with development of disorders like cancer. Several isoforms of Integrin were found to have tumor suppressor effect. Some components in the molecule-linkage of focal contact are actin-binding proteins as well as substrates of kinase in the Integrin initiated signal pathway to play a role as signal transducer. Some of these molecules exhibited tumor suppressor effect too. Decreased expression of E-Cadherin has been demonstrated in many epithelium originated carcinomas. Cadherin associated membrane adhesion plaque molecule β-Catenin is also involved in the oncogene Wnt signal pathway. Both E-Cadherin and β-Catenin were proved respectively with tumor suppressor effect against invasiveness and metastasis. That Cadherin is important for the posttranslationally functional expression of Connexin has been supported by evidence from developmental biology and cancer cell differentiation studies to suggest that some sort of interrelation feedback control exists between the two signal pathways.     

Molecular basis and genetic improvement of economically important traits in aquaculture animals

Aquaculture has been believed to be a major Chinese contribution to the world. In recent 20 years, genome and other genetic technologies have promoted significant advances in basic studies on molecular basis and genetic improvement of aquaculture animals, and complete genomes of some main aquaculture animals have been sequenced or announced to be sequenced since the beginning of this century. Here, we review some significant breakthrough progress of aquaculture genetic improvement technologies including genome technologies, somatic cell nuclear transfer and stem cell technologies, outline the molecular basis of several economically important traits including reproduction, sex, growth, disease resistance, cold tolerance and hypoxia tolerance, and present a series of candidate trait-related genes. Finally, some application cases of genetic improvement are introduced in aquaculture animals, especially in China, and several development trends are highlighted in the near future.     

The Teacher and The Student in the Art of The Teaching

How could we have a effective teaching?We,as teachers,always think about this question and always hope to have better experiences to supple- ment us.The art of teaching lies in the teaching of the teacher and the studying of the students.During this course, a teacher's quality will be re- garded as an important factor in the art of teaching which we have to think over and discuss.Of course,the factors of students will be undoubtedly tak- en into consideration because of their significance.HereⅠwould like to sunmaarize the following points to improve our teaching effect.     

Investigation on the Copper Content of Matte Smelting Slag in Peirce-Smith Converter

The copper contents and its existing forms in the slags during the slag-making stage of Peirce-Smith converters in Guixi Smelter, Jiangxi Province, China have been investigated. The investigation was based on plant trials with the corresponding thermodynamic calculations and kinetic considerations. From the plant data, the total copper content in the slags was in the range of 2% to 8% (mass fraction). The mechanical entrainment of matte drops has been found to be the main cause of the copper loss. The suspension index, defined as the ratio of the mass fraction of copper in suspended matte drops in the slag to that in bulk of the matte phase, has been adopted to quantify the matte entrainment. The values of this parameter estimated in this work have been found mainly within a range of 2.5%-8.0%. The Fe₃O₄ content in the slag has been estimated to be the most important factor, among others, influencing the separation of slag with matte and, consequently, the copper loss from the slag.     

Nonequilibrium solvation theory： Comparison,modification and application

Faults existing in the current theories of nonequilibrium solvation have been clarified in this report.Based on a novel expression of solvation free energy for nonequilibrium, generalized formulations of solvent reorganization energy for electron transfer and of solvation shift for spectrum have been established. Furthermore, a new form of solvent reorganization energy for electron transfer in two-sphere case, which greatly differs from the one by Marcus, has been deduced. A single-sphere model for solvation shift of spectrum has been put forward both by deducing the generalized formulations and by showing the correct forms of self-energy of reaction field. It has been concluded that the current theories overestimate the solvent reorganization energy and the solvation shift by a factor of about 2. By applying the models established, the discrepancies between the theory and experiments before have been perfectly explained.     

Evidence for existence of a close association between CD14 and CXCR4 on monocytic cell line U937

The surface expression of HIV-1 coreceptors (CXCR4 and CCR5) on monocytes can be regulated by the ligand of CD14, and the susceptibility of the cells to HIV-1 is then changed. Our previous study found that monoclonal antibody against CD14 could dramatically inhibit CXCR4-mediated chemotaxis and cell-cell fusion. Based on these studies, we explored potential relationship between CD14 and CXCR4 on monocytic cell line U937. Flow cytometry analysis showed that anti-CXCR4 monoclonal antibody (mAb) 12G5 strongly inhibited binding of the FITC-conjugated anti-CD14 monoclonal antibodies (TUK4 and UCHM1) to U937, while another CXCR4-specific mAb B-R24 did not show any effect on this binding. On the other hand, two anti-CD14 monoclonal antibodies (TUK4 and UCH-M1) obviously inhibited the binding of the PE-conjugated anti-CXCR4 mAb 12G5 to U937 but did not inhibit the binding of mAb 12G5 to CXCR4-transfected 3T3 cells (3T3.T4.CXCR4), which indicates that the blocking of mAb 12G5 binding to CXCR4 by CD14-specific mAbs is not involved in the possibility that CD14-specific mAbs directly bind to CXCR4. These results suggested existence of a close association between CD14 and CXCR4 on monocytic cell line U937.     

Involvement of chemokine receptors in breast cancer metastasis

Breast cancer is characterized by a distinct metastatic pattern involving the regional lymph nodes, bone marrow, lung and liver. Tumour cell migration and metastasis share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. Here we report that the chemokine receptors CXCR4 and CCR7 are highly expressed in human breast cancer cells, malignant breast tumours and metastases. Their respective ligands CXCL12/SDF-1alpha and CCL21/6Ckine exhibit peak levels of expression in organs representing the first destinations of breast cancer metastasis. In breast cancer cells, signalling through CXCR4 or CCR7 mediates actin polymerization and pseudopodia formation, and subsequently induces chemotactic and invasive responses. In vivo, neutralizing the interactions of CXCL12/CXCR4 significantly impairs metastasis of breast cancer cells to regional lymph nodes and lung. Malignant melanoma, which has a similar metastatic pattern as breast cancer but also a high incidence of skin metastases, shows high expression levels of CCR10 in addition to CXCR4 and CCR7. Our findings indicate that chemokines and their receptors have a critical role in determining the metastatic destination of tumour cells.     

Productive dual infection of human CD4+ T lymphocytes by HIV-1 and HHV-6

Although infection by HIV-1 has been implicated as the primary cause of AIDS and related disorders, cofactorial mechanisms may be involved in the pathogenesis of the disease. For example, several viruses commonly detected in AIDS patients and capable of transactivating the long terminal repeat of HIV-1, such as herpesviruses, papovaviruses, adenoviruses and HTLV-I have been suggested as potential cofactors. Another candidate is human herpesvirus-6 (HHV-6, originally designated human B-lymphotropic virus), which has not only been identified in most patients with AIDS by virus isolation, DNA amplification techniques and serological analysis, but is also predominantly tropic and cytopathic in vitro for CD4+ T lymphocytes. Here we demonstrate that HHV-6 and HIV-1 can productively co-infect individual human CD4+ T lymphocytes, resulting in accelerated HIV-1 expression and cellular death. We also present evidence that HHV-6 transactivates the HIV-1 long terminal repeat (LTR). These observations indicate that HHV-6 might contribute directly or indirectly to the depletion of CD4+ T cells in AIDS.     

白细胞介素23基因沉默对支气管哮喘小鼠的影响

目的观察白细胞介素23(IL-23)基因沉默对肺组织IL-23蛋白表达、哮喘鼠气道炎症和支气管肺泡灌洗液(BALF)中干扰素(IFN-γ)、白细胞介素-5(IL-5)、肿瘤坏死因子-α(TNF-α)、细胞间黏附分子-1(ICAM-1)水平的影响.方法构建siRNA IL-23表达载体并通过脂质体转染获得高浓度的含有siRNA IL-23的浓缩液,RT-PCR和WB法检测IL-23mRNA及IL-23蛋白表达水平,确定转染成功.通过滴鼻方式吸入到卵蛋白(OVA)致敏的小鼠体内,观察其对BALF中炎症细胞的影响;ELISA方法检测支气管肺泡灌洗液(BALF)中细胞因子IFN-γ,IL-5,TNF-α,ICAM-1的变化;HE染色观察肺组织病理学改变;WB法检测肺组织中IL-23蛋白表达.结果与对照组相比,模型组及空质粒组BALF中IL-5,TNF-α,ICAM-1水平升高,IFN-γ水平下降,肺组织中IL-23蛋白表达量升高(P0.01),沉默组上述各项指标明显下降,IFN-γ水平升高(P0.01);病理学检测结果表明:与对照组相比,模型组和空质粒组气道内有大量炎性细胞浸润,沉默组炎症受到抑制(P0.01).结论 IL-23在哮喘发病中起重要作用,阻断其基因表达可以明显改变哮喘症状.     

Protection of macaques from vaginal SHIV challenge by vaginally delivered inhibitors of virus-cell fusion

Human immunodeficiency virus type 1 (HIV-1) continues to spread, principally by heterosexual sex, but no vaccine is available. Hence, alternative prevention methods are needed to supplement educational and behavioural-modification programmes. One such approach is a vaginal microbicide: the application of inhibitory compounds before intercourse. Here, we have evaluated the microbicide concept using the rhesus macaque 'high dose' vaginal transmission model with a CCR5-receptor-using simian-human immunodeficiency virus (SHIV-162P3) and three compounds that inhibit different stages of the virus-cell attachment and entry process. These compounds are BMS-378806, a small molecule that binds the viral gp120 glycoprotein and prevents its attachment to the CD4 and CCR5 receptors, CMPD167, a small molecule that binds to CCR5 to inhibit gp120 association, and C52L, a bacterially expressed peptide inhibitor of gp41-mediated fusion. In vitro, all three compounds inhibit infection of T cells and cervical tissue explants, and C52L acts synergistically with CMPD167 or BMS-378806 to inhibit infection of cell lines. In vivo, significant protection was achieved using each compound alone and in combinations. CMPD167 and BMS-378806 were protective even when applied 6 h before challenge.     

雌二醇对EAE大鼠ICAM-1和INF-γ表达的影响

目的探讨雌二醇对去卵巢后EAE大鼠的免疫抑制作用及其机制.方法制备去卵巢后10 d的EAE大鼠模型,随机分为EAE组、E2治疗组和佐剂组.E2治疗组在免疫后（post-inoculation,p.i.）0～5 d每日肌注E2（250μg/kg）一次.在p.i.6,8,10,12,14,16 d处死动物,用免疫组化技术检测脑和脊髓不同部位ICAM-1,IFN-γ的表达,并对EAE组ICAM-1和IFN-γ进行相关分析.结果与EAE组相比较,在p.i.6～12 d,E2治疗组血清E2浓度升高,临床症状评分降低,体重减轻减少,发病率较低,上述差异均有统计学意义;在p.i.10～16 d,E2治疗组ICAM-1与IFN-γ的表达降低,且具有统计学意义.EAE组ICAM-1与IFN-γ表达呈显著正相关性.结论E2能够有效抑制EAE,其抑制机制与E2下调ICAM-1,IFN-γ的表达进而促使Th细胞发生转分化有关。     

Interferon-γ links ultraviolet radiation to melanomagenesis in mice

Cutaneous malignant melanoma is a highly aggressive and frequently chemoresistant cancer, the incidence of which continues to rise. Epidemiological studies show that the major aetiological melanoma risk factor is ultraviolet (UV) solar radiation, with the highest risk associated with intermittent burning doses, especially during childhood. We have experimentally validated these epidemiological findings using the hepatocyte growth factor/scatter factor transgenic mouse model, which develops lesions in stages highly reminiscent of human melanoma with respect to biological, genetic and aetiological criteria, but only when irradiated as neonatal pups with UVB, not UVA. However, the mechanisms underlying UVB-initiated, neonatal-specific melanomagenesis remain largely unknown. Here we introduce a mouse model permitting fluorescence-aided melanocyte imaging and isolation following in vivo UV irradiation. We use expression profiling to show that activated neonatal skin melanocytes isolated following a melanomagenic UVB dose bear a distinct, persistent interferon response signature, including genes associated with immunoevasion. UVB-induced melanocyte activation, characterized by aberrant growth and migration, was abolished by antibody-mediated systemic blockade of interferon-γ (IFN-γ), but not type-I interferons. IFN-γ was produced by macrophages recruited to neonatal skin by UVB-induced ligands to the chemokine receptor Ccr2. Admixed recruited skin macrophages enhanced transplanted melanoma growth by inhibiting apoptosis; notably, IFN-γ blockade abolished macrophage-enhanced melanoma growth and survival. IFN-γ-producing macrophages were also identified in 70% of human melanomas examined. Our data reveal an unanticipated role for IFN-γ in promoting melanocytic cell survival/immunoevasion, identifying a novel candidate therapeutic target for a subset of melanoma patients.     

斯氏狸殖吸虫感染大鼠致肝纤维化形成过程中IL-4和IFN-γ表达及意义

 探讨斯氏狸殖吸虫感染大鼠致肝纤维化形成过程中细胞因子IL-4和IFN-γ表达及意义,为阐明Th1/Th2在斯氏狸殖吸虫感染大鼠肝纤维化形成及调节作用提供实验依据.SD大鼠36只,随机分为正常对照组(n=6)、感染1周组(n=5)、感染2周组(n=5)、感染4周组(n=5)、感染8周组(n=5)、感染12周组(n=5)和感染16周组(n=5),每鼠腹腔注射斯氏狸殖吸虫囊蚴15个.按感染时间处死各组大鼠,观测各项指标.HE染色和V G染色观察肝组织纤维化病理形态学变化.免疫组织化学法测定IL-4,IFN-γ在大鼠肝纤维化形成过程中的表达动态变化.HE染色和V G染色肝组织病理形态学结果显示:随着感染时间的延长,胶原纤维面积比值(S/T)和肝纤维化评级在逐渐增加,肝组织纤维化的程度逐渐加重.免疫组织化学显示:IFN-γ的表达阳性细胞百分率在1~8周逐渐增加,到第8周末时达到最大,在12周到16周又逐渐减少;而IL-4表达阳性细胞百分率在1~16周逐渐增加,到第12周末IL-4表达开始增加迅速. 斯氏狸殖吸虫感染大鼠可引起肝脏纤维化病变,IL-4和IFN-γ在斯氏狸殖吸虫感染大鼠致肝纤维化形成过程中表达增加,其纤维化病变程度与感染时间、IL-4和IFN-γ的表达增加有关.提示Th1细胞分泌的细胞因子IFN-γ和Th2细胞分泌的细胞因子IL-4在斯氏狸殖吸虫感染大鼠致肝纤维化的自发性免疫调节中起作用.     

Balanced responsiveness to chemoattractants from adjacent zones determines B-cell position

B lymphocytes re-circulate between B-cell-rich compartments (follicles or B zones) in secondary lymphoid organs, surveying for antigen. After antigen binding, B cells move to the boundary of B and T zones to interact with T-helper cells. Despite the importance of B--T-cell interactions for the induction of antibody responses, the mechanism causing B-cell movement to the T zone has not been defined. Here we show that antigen-engaged B cells have increased expression of CCR7, the receptor for the T-zone chemokines CCL19 and CCL21, and that they exhibit increased responsiveness to both chemoattractants. In mice lacking lymphoid CCL19 and CCL21 chemokines, or with B cells that lack CCR7, antigen engagement fails to cause movement to the T zone. Using retroviral-mediated gene transfer we demonstrate that increased expression of CCR7 is sufficient to direct B cells to the T zone. Reciprocally, overexpression of CXCR5, the receptor for the B-zone chemokine CXCL13, is sufficient to overcome antigen-induced B-cell movement to the T zone. These findings define the mechanism of B-cell relocalization in response to antigen, and establish that cell position in vivo can be determined by the balance of responsiveness to chemoattractants made in separate but adjacent zones.