结核杆菌HSP65与IL—12多价DNA疫苗的构建

[目的]构建结核杆菌H37RV株HSP65基因与IL-12基因的共表达载体pVIVO2-HSP65-IL-12,并研究其在Vero—E6细胞内表达的可行性,为新一代结核多价DNA疫苗寻找理论依据。[方法]采用PCR技术,从培养的结核杆菌H37RV中抽提HSP65基因,克隆到pVIVO2-MCS上的一个多克隆位点,构建pVIVO2-HSP65,将质粒pORF—IL-12上的IL-12基因经双酶切后,亚克隆到pVIVO2-HSP65上,构建成共表达载体pVIVO2-HSP65-IL-12。并经XbaⅠ／AvrⅡ和NcoⅠ／NheⅠ进行双酶切和测序鉴定;用间接免疫荧光法（IFA）检测HSP65和mIL-12基因在Vero—E6细胞中的表达。[结果]双酶切和测序分析证明HSP65基因和mIL-12基因成功克隆到pVIVO2-MCS上,且方向正确,序列无突变;间接免疫荧光试验结果为阳性。[结论]共表达载体pVIVO2-HSP65-IL-12构建成功,且pVIVO2-HSP65-IL-12可在Vero—E6细胞中获得共表达。     

RASSF1A基因转染对人肺腺癌细胞株A549增殖的抑制作用

目的：观察外源性RASSF1A基因对人肺腺癌细胞A549增殖及NF- κB亚单位P65表达的影响。方法：利用脂质体转染技术将真核表达重组体pcDNA3.0-RASSF1A质粒和空载体pcDNA3.0质粒分别导入A549细胞，经G418筛选后获得稳定转染细胞克隆，Western blotting检测RASSF1A基因表达。采用MTT(四甲基偶氮唑盐)法、流式细胞仪分析转染细胞的生物学行为。 RT-PCR和Western blotting检测基因转染对P65表达的影响。结果：经脂质体转染和筛选，建立了稳定表达RASSF1A基因的A549细胞系。与未转染组和转染空白载体组比较，转染RASSF1A基因的细胞生长速度明显减慢（P<0.05），细胞周期中G1/G0期比例明显增加（P<0.05），而S期比例减少；转染组细胞核内P65蛋白表达明显降低（P<0.05），而全细胞P65蛋白及mRNA表达未见明显变化。结论：RASSF1A基因可能通过抑制P65活性而抑制人肺腺癌细胞A549的生长。     

Evidence that AKT and GSK-3β pathway are involved in acute hyperhomocysteinemia

Homocysteine is a neurotoxic amino acid that accumulates in several disorders including homocystinuria, neurodegenerative and neuroinflammatory diseases. In the present study we evaluated the effect of acute and chronic hyperhomocysteinemia on Akt, NF-κB/p65, GSK-3β, as well as Tau protein in hippocampus of rats. For acute treatment, rats received a single injection of homocysteine (0.6 μmol/g body weight) or saline (control). For chronic treatment, rats received daily subcutaneous injections of homocysteine (0.3-0.6 μmol/g body weight) or saline (control) from the 6th to the 28th days-of-age. One or 12h after the last injection, rats were euthanized, the hippocampus was removed and samples were submitted to electrophoresis followed by Western blotting. Results showed that acute hyperhomocysteinemia increases Akt phosphorylation, cytosolic and nuclear immunocontent of NF-κB/p65 subunit and Tau protein phosphorylation, but reduces GSK-3β phosphorylation at 1h after homocysteine injection. However, 12h after acute hyperhomocysteinemia there is no effect on Akt and GSK-3β phosphorylation. Furthermore, chronic hyperhomocysteinemia did not alter Akt and GSK-3β phosphorylation at 1h and 12h after the last administration of this amino acid. Our data showed that Akt, NF-κB/p65, GSK-3β and Tau protein are activated in hippocampus of rats subjected to acute hyperhomocysteinemia, suggesting that these signaling pathways may be, at least in part, important contributors to the neuroinflammation and/or brain dysfunction observed in some hyperhomocystinuric patients.     

Pseudorabies Virus ICP0 Abolishes Tumor Necrosis Factor Alpha-Induced NF-κB Activation by Degrading P65

Nuclear factor κB (NF-κB) is involved in a wide range of innate immune activities in host cells and serves as an important component of a host’s immunity system. To survive in infected cells, viruses have evolved intricate strategies to evade the host immune response. Pseudorabies virus (PRV) is a member of the alpha herpesvirus family and is capable of causing reproductive and neurological dysfunction in pigs. PRV has a large DNA genome and therefore has the ability to encode numerous proteins that modulate host innate immune responses. In the present study, we demonstrated that the PRV-encoded immediate early protein ICP0 inhibits the tumor necrosis factor alpha (TNF-α)-mediated NF-κB signaling pathway. An in-depth study showed that ICP0 protein was able to limit NF-κB activation and decreased the expression of inflammatory cytokines interleukin-6 (IL-6) and interleukin 8 (IL-8). In addition, ICP0 blocked the activation of NF-κB through interacting with p65, degrading its protein expression and limiting its phosphorylation. PRV protein ICP0 is shown for the first time to enable escape from innate immune response through the regulation of NF-κB during PRV infection. These results illustrate that PRV ICP0 is able to block NF-κB activation. This mechanism may represent a critical role in the early events leading to PRV infection.     

Whether Alzheimer’s diseases related genes also differently express in the hippocampus of Ts65Dn mice?

Background: Down syndrome is a condition which extra genetic material causes delays in child development, both mentally and physically. Strengthening the study of the neural defects of DS is of great significance. Methods: Ts65Dn mice were used in this study. We removed the brain and isolated their hippocampus. We customized 54 genes in one PCR arrays, included some important genes related to Alzheimer’s disease. The expression of genes were detected by RT-PCR. Results: PCR arrays contained 54 genes related to Alzheimer’s disease. After real-time PCR, three genes (Nae1, APP and Mapt) expressed differently in the hippocampus of Ts65Dn, compared with the normal mice. Nae1 was decreased significantly, while APP and Mapt were increased obviously. The levels of fold-changes of Nae1, APP and Mapt were 86.19, 4.49 and 2.89 respectively. Significantly different levels of expression were found in the Ts65Dn mice compared with the normal control group (P=0.00 for Nae1, P=0.02 for APP, P=0.01 for Mapt respectively). Conclusions: There are differential expressed genes in the hippocampus of Ts65Dn mice that may be closely related to Alzheimer’s disease. PCR array technology was used in the screening and identification of these genes.     

Low correlation of human cytomegalovirus DNA amplification by polymerase chain reaction with cytomegalovirus disease in organ transplant recipients

Seventy-five organ transplant recipients underwent prolonged virological and serological follow-up for early detection of human Cytomegalovirus (HCMV) infection after transplantation. HCMV DNA detection by nested polymerase chain reaction (PCR) and HCMV early structural antigen (pp65) detection were carried out in 576 peripheral blood leucocyte (PBL) samples. Furthermore, 563 blood specimens were investigated by a commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of specific immunoglobulins G, M, and A against HCMV structural antigens. In eight of nine symptomatic organ transplant recipients, HCMV DNA was detected in one or more consecutive blood samples. HCMV DNA PCR was also positive in one or more samples from eight patients who never developed HCMV-related symptoms. HCMV pp65 antigen was detected almost exclusively in PBL samples from organ transplant recipients suffering from HCMV disease. However, antigenaemia was not detected in four PCR positive patients presenting clinical signs attributable to HCMV infection. Two of the initially HCMV DNA positive samples were not confirmed by retesting and hybridisation. The results of the present study demonstrate that despite the high specificity of nested PCR, HCMV DNA may be detected in the absence of clinical symptoms attributable to HCMV infection. In asymptomatic reactivation, limited replication of viral DNA may be responsible for positive results of PCR without any clinical relevance. In this context, pp65-antigen detection from PBL seems to have a better prognostic value, but is not always detected when clinical symptoms are present. © 1994 Wiley-Liss, Inc.     

热休克蛋白65与免疫关系研究进展

原核生物的Hsp65与免疫的关系非常密切.它既具有免疫原性又具有反应原性,可作为一种保护性抗原,而且与人的Hsp60高度同源,与动脉粥样硬化、佐剂性关节炎、糖尿病等自身免疫病有关,在上述疾病的早期可诱导免疫反应,后期可产生保护作用.更为重要的是,它形成的二聚体结构可导致某些疏水区暴露在表面,有利于非特异性地结合抗原肽 作为分子佐剂,与其他抗原构建的复合物具有交叉递呈功能,尤其能激活细胞毒性T细胞,可用于肿瘤或病毒病的预防和治疗免疫.有研究者将.其应用于开发与其相关的预防或治疗分枝杆菌病、肿瘤或病毒性疾病的疫苗中,并取得了初步成效.     

细菌脂多糖联合高体积分数氧对未成熟大鼠脑发育的影响

目的 探讨细菌脂多糖(LPS)、高体积分数氧(高氧)单独或联合应用对新生大鼠脑发育的影响及其相关机制.方法 2日龄(P2)新生SD大鼠120只随机分为4组:空气组、LPS组、高氧组、LPS+高氧组,分别观察各组大鼠的一般情况,记录其每日体质量.7日龄(P7)时,免疫组织化学法检测各组大鼠脑组织中半胱氨酸天冬氨酸蛋白酶3(Caspase-3)、核转录因子P65(NF-κB P65)的表达情况,ELISA法检测各组大鼠脑组织中IL-6、8-异-前列腺素F2α(8-iso-PGF2α)水平;12日龄(P12)时,免疫组织化学法检测各组大鼠脑组织碱性髓鞘蛋白(MBP)的表达.结果不同处理组中Caspase-3及NF-κB P65表达水平高低依次为LPS+高氧组、LPS组/高氧组、空气组,前3组与空气组相比差异均有统计学意义(P均＜0.05),且LPS+高氧组与高氧组、LPS组相比差异亦均有统计学意义(P均＜0.01);MBP的表达水平高低依次为空气组、高氧组、LPS组、LPS+高氧组,后3组与空气组相比差异均有统计学意义(P均＜0.05),且LPS+高氧组与高氧组、LPS组相比差异亦均有统计学意义(P均＜0.01).各组新生大鼠IL-6表达水平高低依次为LPS+高氧组、LPS组、高氧组、空气组;8-iso-PGF2α表达水平高低依次为LPS+高氧组、高氧组、LPS组、空气组,而且各组之间比较差异均有统计学意义(P均＜0.05).结论 感染及高氧均可致新生大鼠脑损伤,导致神经细胞凋亡和MBP表达减少,且感染与高氧同时存在时能加重二者单独作用时脑损伤的程度.其机制可能为炎性反应及氧化应激通过Toll样受体后发生协同作用,激活核转录因子NF-κB P65,并通过Caspase-3介导神经细胞凋亡及脑白质损伤.     

The bacterial aetiology of pleural empyema. A descriptive and comparative metagenomic study

ObjectivesThe view of pleural empyema as a complication of bacterial pneumonia is changing because many patients lack evidence of underlying pneumonia. To further our understanding of pathophysiological mechanisms, we conducted in-depth microbiological characterization of empyemas in clinically well-characterized patients and investigated observed microbial parallels between pleural empyemas and brain abscesses.MethodsCulture-positive and/or 16S rRNA gene PCR-positive pleural fluids were analysed using massive parallel sequencing of the 16S rRNA and rpoB genes. Clinical details were evaluated by medical record review. Comparative analysis with brain abscesses was performed using metagenomic data from a national Norwegian study.ResultsSixty-four individuals with empyema were included. Thirty-seven had a well-defined microbial aetiology, while 27, all of whom had community-acquired infections, did not. In the latter subset, Fusobacterium nucleatum and/or Streptococcus intermedius was detected in 26 patients, of which 18 had additional facultative and/or anaerobic species in various combinations. For this group, there was 65.5% species overlap with brain abscesses; predisposing factors included dental infection, minor chest trauma, chronic obstructive pulmonary disease, drug abuse, alcoholism and diabetes mellitus. Altogether, massive parallel sequencing yielded 385 bacterial detections, whereas culture detected 38 (10%) and 16S rRNA gene PCR/Sanger-based sequencing detected 87 (23%).ConclusionsA subgroup of pleural empyema appears to be caused by a set of bacteria not normally considered to be involved in pneumonia. Such empyemas appear to have a similar microbial profile to oral/sinus-derived brain abscesses, supporting spread from the oral cavity, potentially haematogenously. We suggest reserving the term ‘primary empyema’ for these infections.     

严重惊厥发作过程中核因子-κB活化与神经元凋亡的关系

目的：探讨戊四氮(PTZ)所致大鼠严重惊厥发作模型中核因子κB(NFκB)活化与神经细胞凋亡的关系。方法：42只大鼠随机分为7组,即对照组、致惊后3h、6h、12h、24h、48h和吡咯啉烷二硫代氨基甲酸盐(PDTC)+PTZ组。免疫组织化学法检测海马CA1区NFκB亚基p65核移位;TUNEL和流式细胞仪检测海马细胞凋亡。结果：流式细胞仪和TUNEL法显示惊厥发作后有细胞凋亡的发生,24h达高峰,与对照组相比分别为(12.54±4.99)%vs(2.24±0.57)%和(61.62±4.99)个/gcsvs(3.35±0.89)个/gcs,P均<0.001;对照组大鼠海马未见p65核移位细胞,而致惊后p65核移位细胞显著上调,24h达高峰(32.30±4.71)个/gcs。PDTC预处理组与致惊24h组相比p65核移位及细胞凋亡明显减少。结论：NFκB活化在严重惊厥发作所致的细胞凋亡发生中发挥重要作用;PDTC可通过抑制NFκB的表达而减少惊厥后的细胞凋亡。