Inhibition of Japanese Encephalitis Virus Infection by Flavivirus Recombinant E Protein Domain Ⅲ

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus closely related to the human pathogens including yellow fever virus, dengue virus and West Nile virus. There are currently no effective antiviral therapies for all of the flavivirus and only a few highly effective vaccines are licensed for human use. In this paper, the E protein domain III (DIII) of six heterologous flaviviruses (DENV1-4, WNV and JEV) was expressed in Escherichia coli successfully. The proteins were purified after a solubilization and refolding procedure, characterized by SDS-PAGE and Western blotting. Competitive inhibition showed that all recombinant flavivirus DIII proteins blocked the entry of JEV into BHK-21 cells. Further studies indicated that antibodies induced by the soluble recombinant flavivirus DIII partially protected mice against lethal JEV challenge. These results demonstrated that recombinant flavivirus DIII proteins could inhibit JEV infection competitively, and immunization with proper folding flavivirus DIII induced cross-protection against JEV infection in mice, implying a possible role of DIII for the cross-protection among flavivirus as well as its use in antigens for immunization in animal models.

Receptor-binding domain of SARS-Cov spike protein: Soluble expression in E.coli, purification and functional characterization

AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion tags （glutathione S-transferase, GST; thioredoxin, Trx; maltose-binding protein, MBP）, which preferably contributes to increasing solubility and to facilitating the proper folding of heteroprotein, were used to acquire the soluble and functional expression of RBD protein in Escherichia coli （BL21（DE3） and Rosetta-gamiB （DE3） strains）. The receptor binding ability of the purified soluble RBD protein was then detected by ELISA and flow cytometry assay. RESULTS： RBD of SARS-Cov spike protein was expressed as inclusion body when fused as TrxA tag form in both BL21 （DE3） and Rosetta-gamiB （DE3） under many different cultures and induction conditions. And there was no visible expression band on SDS-PAGE when RBD was expressed as MBP tagged form. Only GST tagged RBD was soluble expressed in BL21（DE3）, and the protein was purified by AKTA Prime Chromatography system. The ELISA data showed that GST.RBD antigen had positive reaction with anti-RBD mouse monoclonal antibody 1A5. Further flow cytometry assay demonstrated the high efficiency of RBD＇s binding ability to ACE2 （angiotensin-converting enzyme 2） positive Vero E6 cell. And ACE2 was proved as a cellular receptor that meditated an initial-affinity interaction with SARS-Cov spike protein. The geometrical mean of GST and GST.RBD binding to Vero E6 cells were 77.08 and 352.73 respectively. CONCLUSION： In this paper, we get sufficient soluble N terminal GST tagged RBD protein expressed in EcoliBL21 （DE3）; data from ELISA and flow cytometry assay demonstrate that the recombinant protein is functional and binding to ACE2 positive Vero E6 cell efficiently. And the recombinant RBD derived from E.coli can be used to developing subunit vaccine to block S protein binding with receptor and to neutralizing SARS-Cov infection.

Expression of Major Antigen Domains of E2 Gene of CSFV and Analysis of its Immunological Activity

E2 is an envelope glycoprotein of Classical swine fever virus (CSFV) and contains sequential neutralizing epitopes to induce virus-neutralizing antibodies and mount protective immunity in the natural host. In this study, four antigen domains (ABCD) of the E2 gene was cloned from CSFV Shimen strain into the retroviral vector pBABE puro and expressed in eukaryotic cell (PK15) by an retroviral gene expression system, and the activity of recombinant E2 protein to induce immune responses was evaluated in rabbits. The results indicated that recombinant E2 protein can be recognized by fluorescence antibodies of CSFV and CSFV positive serum (Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China) using Western blot, indirect immunofluorescence antibody test (IFAT) and ELISA, Furthermore, anti-CSFV specific antibodies and lymphocyte proliferation were elicited and increased by recombinant protein after vaccination. In the challenge test, all of rabbits vaccinated with recombinant protein and Chinese vaccine strain (C-strain) were fully protected from a rabbit spleen virus challenge. These results indicated that a retroviral-based epitope-vaccine carrying the major antigen domains of E2 is able to induce high level of epitope-specific antibodies and exhibits similar protective capability with that induced by the C-strain, and encourages further work towards the development of a vaccine against CSFV infection.

长链非编码RNA人类白细胞抗原复合体18通过微RNA-497-5p/细胞周期蛋白E1轴调节弥漫性大B细胞淋巴瘤的增殖、凋亡和侵袭

目的 探讨长链非编码RNA人类白细胞抗原复合体18(lncRNA HCG18)调控微RNA-497-5p(miR-497-5p)/细胞周期蛋白E1(CCNE1)轴对弥漫性大B细胞淋巴瘤(DLBCL)细胞增殖、凋亡和侵袭的影响。方法 实时荧光定量PCR(qRT-PCR)、蛋白质印迹法分别检测2018年5月至2021年5月收集的恩施土家族苗族自治州中心医院DLBCL病人淋巴组织、良性淋巴结增生病人的淋巴组织、人正常B细胞永生化细胞HMy2.CIR、DLBCL细胞系SU-DHL-1、OCI-LY8、U2932中HCG18、miR-497-5p表达及CCNE1蛋白表达,将OCI-LY8细胞分为Ct组(正常培养的OCI-LY8细胞)、pcDNA组(细胞转染过表达物阴性对照)、pcDNA-HCG18组(细胞转染HCG18过表达物)、si-NC组(细胞转染小干扰RNA阴性对照)、si-HCG18组(细胞转染HCG18小干扰RNA)、si-HCG18+inhibitorNC组(细胞转染HCG18小干扰RNA和抑制物阴性对照)、si-HCG18+miR-497-5p inhibitor组(细胞转染HCG18小干扰RNA和miR-497-5p抑制物),CCK-8法检测细胞增殖,流式细胞术检测细胞凋亡,Transwell检测细胞侵袭,蛋白质印迹法检测CCNE1、增殖细胞核抗原(PCNA)、Bcl-2相关X蛋白(Bax)、基质金属蛋白酶9(MMP-9)蛋白表达,双萤光素酶验证HCG18与miR-497-5p、miR-497-5p与CCNE1的关系。结果 在DLBCL淋巴组织和细胞中,HCG18、CCNE1蛋白高表达,miR-497-5p低表达,且在OCI-LY8细胞中HCG18、CCNE1蛋白表达上调最高,miR-497-5p表达下调最多(P<0.05),因此,以OCI-LY8细胞进行后续研究,与si-NC组比较,si-HCG18组HCG18(0.26±0.03比1.01±0.01)、CCNE1蛋白(0.45±0.03比1.44±0.19)表达降低,miR-497-5p(1.95±0.14比1.03±0.02)表达升高(P<0.05),与pcDNA组比较,pcDNA-HCG18组HCG18(1.96±0.23比1.02±0.01)、CCNE1蛋白(2.33±0.21比1.42±0.18)表达升高,miR-497-5p(0.28±0.02比1.02±0.02)表达降低(P<0.05),与siHCG18组、si-HCG18+inhibitor NC组比较,miR-497-5p表达降低(1.21±0.09比1.95±0.14、1.94±0.13),CCNE1蛋白(0.87±0.08比0.45±0.03、0.44±0.04)表达上调(P<0.05),沉默HCG18可抑制OCI-LY8细胞增殖、侵袭行为及PCNA、MMP-9蛋白表达,诱导细胞凋亡及Bax蛋白表达,而上调HCG18则呈相反趋势,下调miR-497-5p逆转了沉默HCG18对OCI-LY8细胞增殖、侵袭、凋亡的影响,HCG18靶向调控miR-497-5p/CCNE1。结论 沉默HCG18可能通过调控miR-497-5p/CCNE1抑制OCI-LY8细胞增殖、侵袭,诱导细胞凋亡。

肺炎支原体肺炎合并哮喘患儿血清维生素D、CD5L、补体C3、IgE水平变化及与病情和炎症反应程度的关系

目的探讨肺炎支原体肺炎(MPP)合并哮喘患儿血清维生素D、CD5抗原样蛋白(CD5L)、补体C3、免疫球蛋白E(IgE)的水平变化及其临床意义。方法回顾性选取2020年1月—2022年6月长江大学附属荆州医院确诊的55例MPP合并支气管哮喘患儿作为观察组,另随机选取同期来该院就诊的55例MPP但无支气管哮喘患儿作为对照组。比较两组维生素D、CD5L、补体C3、补体C4、IgG、IgM、IgE、用力肺活量(FVC)、第1秒用力呼气容积(FEV1)、呼气流量峰值(PEF)、肿瘤坏死因子-α(TNF-α)、转化生长因子-β_(1)(TGF-β_(1))、基质金属蛋白酶2(MMP-2)、MMP-9。结果观察组维生素D、CD5L低于对照组,补体C3、补体C4、IgG、IgM、IgE高于对照组(P<0.05)。观察组FVC、FEV1、PEF低于对照组,TNF-α、MMP-2、MMP-9高于对照组(P<0.05)。观察组与对照组TGF-β_(1)水平比较,差异无统计学意义(P>0.05)。高滴度组维生素D低于低滴度组,补体C3、IgG、IgM、IgE高于低滴度组(P<0.05)。高滴度组与低滴度组CD5L、补体C4水平比较,差异无统计学意义(P>0.05)。高滴度组FVC、FEV1、PEF低于低滴度组患者,TNF-α、MMP-2、MMP-9高于低滴度组(P<0.05)。高滴度组与低滴度组TGF-β_(1)比较,差异无统计学意义(P>0.05)。Pearson相关性分析显示,MPP合并哮喘患儿的血清维生素D与TNF-α、MMP-2和MMP-9呈负相关(r=-0.471、-0.663和-0.682,均P<0.05);CD5L与TNF-α、MMP-2、MMP-9呈负相关(r=-0.502、-0.610和-0.634,均P<0.05);TNF-α与补体C3、补体C4、IgG、IgM、IgE测定值水平无相关性(r=0.201、0.114、0.238、0.217、0.226,均P>0.05);TGF-β_(1)与维生素D、CD5L、补体C3、补体C4、IgG、IgM、IgE无相关性(r=-0.083、-0.112、0.233、0.172、0.132、0.094和0.104,均P>0.05);MMP-2与补体C3、补体C4、IgG、IgM、IgE无相关性(r=0.182、0.158、0.192、0.216和0.171,均P>0.05);患儿MMP-9与补体C3、补体C4、IgG、IgM、IgE无相关性(r=0.169、0.134、0.207、0.236和0.185,均P>0.05)。结论MPP合并哮喘患儿维生素D、CD5L水平降低,补体C3、IgE水平升高,并与患儿病毒抗体滴度水平、炎症反应程度有一定的关系。

鸭坦布苏病毒E蛋白及其结构域Ⅰ、Ⅱ、Ⅲ对DEF细胞周期与凋亡的影响

【目的】探究鸭坦布苏病毒(Duck Tambusu virus,DTMUV) E蛋白全长及其结构域I、II和III (DI、DII和DIII)对鸭胚成纤维细胞(Duck embryo fibroblast,DEF)的细胞周期与凋亡的影响。【方法】本研究设计、合成DTMUV E蛋白全长及其DI、DII和DIII真核表达质粒,并转染至DEF,用流式细胞仪检测不同蛋白引起的DEF细胞凋亡和细胞周期的变化。【结果】细胞凋亡结果显示:质粒转染细胞24 h后,E蛋白全长及DI、DII、DIII诱导的DEF早期凋亡率分别是16.4%、15.1%、14.0%和17.2%;质粒转染细胞36 h后,E蛋白全长及DI、DII、DIII诱导的DEF早期凋亡率分别是23.4%、18.5%、26.7%和29.4%。细胞周期检测结果显示:E蛋白全长及DI、DII、DIII的质粒转染细胞24、36 h后,DNA合成期(S期)细胞比例都明显高于pEGFP-N1空载体转染组。质粒转染24 h后,E蛋白及DI、DII、DIII的S期细胞比例分别为5.43%、22.58%、12.75%和12.80%;质粒转染细胞36 h后,E蛋白及DI、DII、DIII的S期细胞比例分别为9.98%、11.44%、10.44%和11.00%。【结论】DTMUV E蛋白全长及其3个结构域均能诱导早期细胞凋亡,引起细胞S期的停滞,但是各蛋白片段诱导细胞凋亡和引起细胞周期变化的能力存在一定差异。

鸭坦布苏病毒E蛋白生物信息学分析

鸭坦布苏病毒(DTMUV)是一种能造成蛋鸭产蛋下降的新型黄病毒,E蛋白是鸭坦布苏病毒主要的抗原蛋白。本试验利用Protparam、ProtScale等相关在线软件预测分析了E蛋白的理化性质、亲水性、跨膜螺旋区、信号肽、亚细胞定位、二、三级结构和T、B细胞抗原表位以及翻译后的修饰位点。结果表明,DTMUV E蛋白的分子式为C2405H3757N649O723S32,由501个氨基酸组成,理论等电点为7.63。该蛋白是定位于病毒衣壳中有2个跨膜螺旋区的稳定性、亲水性蛋白。分别由41.52%、19.96%、32.34%、6.19%的氨基酸参与E蛋白的无规律卷曲、α-螺旋、延伸链和β-转角的形成。三级结构预测模型蛋白覆盖率为100%。该蛋白含有18个潜在的糖基化修饰位点,52个潜在的磷酸化修饰位点,20个潜在的抗原决定簇,其中含有4个连续氨基酸数量超过10个的B细胞抗原表位。选取HLA_DRB1_0801亚型时,CD4+抗原表位有15个强结合肽,43个弱结合肽。对DTMUV E蛋白序列分析显示该蛋白是一种没有信号肽,有跨膜区,具有良好免疫原性的亲水性蛋白,该结果为对E蛋白功能的进一步研究奠定了理论基础。

Axonal growth inhibitors and their receptors in spinal cord injury:from biology to clinical translation

Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.

Soluble programmed death-1 is predictive of hepatitis B surface antigen loss in chronic hepatitis B patients after antiviral treatment

BACKGROUND Hepatitis B surface antigen(HBsAg)loss,a functional cure in patients with chronic hepatitis B(CHB)undergoing antiviral therapy,might be an ideal endpoint of antiviral treatment in clinical practice.The factors that contribute to the functional cure remain unclear,and the predictors of functional cure are worth exploring.The concentration and kinetics of soluble programmed death-1(sPD-1)in patients with CHB may play an important role in elucidating the immune response associated with functional cure after nucleos(t)ide analogs therapy.AIM To investigate the factors associated with HBsAg loss and explore the influence of sPD-1 Levels.METHODS This study analyzed the data and samples from patients with CHB who underwent antiviral treatment in a non-interventional observational study conducted at Peking University First Hospital in Beijing(between 2007 and 2019).All patients were followed up:Serum samples were collected every 3 mo during the first year of antiviral treatment and every 6 mo thereafter.Patients with positive hepatitis B e antigen levels at baseline and with available sequential samples who achieved HBsAg loss during antiviral treatment served as the case group.This case group(n=11)was further matched to 44 positive hepatitis B e anti patients without HBsAg loss as controls.The Spearman’s rank correlation test and receiver operating characteristic curves analysis were performed.RESULTS The sPD-1 Levels were higher in patients with HBsAg loss than in those without HBsAg loss from baseline to month 96,and the differences were significant between the groups at baseline(P=0.0136),months 6(P=0.0003),12(P<0.0001),24(P=0.0007),48(P<0.0001),and 96(P=0.0142).After 6 mo of antiviral treatment,the sPD-1 levels were positively correlated with alanine transaminase(ALT)levels(r=0.5103,P=0.0017),and the sPD-1 levels showed apparent correlation with ALT(r=0.6883,P=0.0192)and HBV DNA(r=0.5601,P=0.0703)levels in patients with HBsAg loss.After 12 mo of antiviral treatment,the sPD-1 levels also showed apparent correlation with ALT(r=0.8134,P=0.0042)and HBV DNA(r=0.6832,P=0.0205)levels in patients with HBsAg loss.The sPD-1 levels were negatively correlated with HBsAg levels in all patients after 12 mo of antiviral treatment,especially at 24(r=-0.356,P=0.0497)and 48(r=-0.4783,P=0.0037)mo.After 6 mo of antiviral treatment,the AUC of sPD-1 for HBsAg loss was 0.898(P=0.000),whereas that of HBsAg was 0.617(P=0.419).The cut-off value of sPD-1 was set at 2.34 log pg/mL;the sensitivity and specificity were 100%and 66.7%,respectively.CONCLUSION The sPD-1 levels at 6 mo can predict HBsAg loss after 144 mo of antiviral treatment.

Immune response modulation in inflammatory bowel diseases by Helicobacter pylori infection

Many studies point to an association between Helicobacter pylori(H.pylori)infection and inflammatory bowel diseases(IBD).Although controversial,this association indicates that the presence of the bacterium somehow affects the course of IBD.It appears that H.pylori infection influences IBD through changes in the diversity of the gut microbiota,and hence in local chemical characteristics,and alteration in the pattern of gut immune response.The gut immune response appears to be modulated by H.pylori infection towards a less aggressive inflammatory response and the establishment of a targeted response to tissue repair.Therefore,a T helper 2(Th2)/macrophage M2 response is stimulated,while the Th1/macrophage M1 response is suppressed.The immunomodulation appears to be associated with intrinsic factors of the bacteria,such as virulence factors-such oncogenic protein cytotoxin-associated antigen A,proteins such H.pylori neutrophil-activating protein,but also with microenvironmental changes that favor permanence of H.pylori in the stomach.These changes include the increase of gastric mucosal pH by urease activity,and suppression of the stomach immune response promoted by evasion mechanisms of the bacterium.Furthermore,there is a causal relationship between H.pylori infection and components of the innate immunity such as the NLR family pyrin domain containing 3 inflammasome that directs IBD toward a better prognosis.

非洲猪瘟病毒CD2v蛋白胞内域与胞外域的原核表达及其抗原性分析

【目的】应用大肠杆菌表达系统表达非洲猪瘟病毒(African swine fever virus,ASFV)CD2v蛋白胞外域(N-端,CD2v-N)与胞内域(C-端,CD2v-C)并分析两者的抗原性,为ASFV检测方法的研发提供试验依据和指导。【方法】构建CD2v-N和CD2v-C的重组原核表达质粒,在体外表达并纯化CD2v-N和CD2v-C蛋白,通过Western blotting对表达蛋白进行鉴定;用表达的CD2v-N和CD2v-C蛋白分别肌内接种免疫新西兰大白兔,共免疫3次,每次间隔2周;每次免疫后14 d,应用ELISA方法测定CD2v-N或CD2v-C的特异性抗体水平;用纯化后的CD2V-N和CD2v-C蛋白作为包被抗原,通过ELISA方法检测95份ASFV感染猪的血清CD2v-N或CD2v-C特异性抗体,比较CD2v-N和CD2v-C在猪体内诱导的免疫反应水平。【结果】重组蛋白CD2v-N和CD2v-C分别以包涵体和可溶性形式表达,分子质量分别为22.9和34.0 ku,均能与猪抗ASFV血清特异性结合;用CD2v-N蛋白首免家兔后14 d,血清中未检测到特异性抗体,而在CD2v-C首免的家兔血清中检测到了高滴度的特异性抗体;三免后14 d,CD2v-N和CD2v-C蛋白免疫家兔的血清特异性抗体效价分别为1∶125000和1∶107;ELISA检测结果显示,ASFV感染猪的血清中CD2v-C特异性抗体水平显著高于CD2v-N(P<0.05)。【结论】本研究表达了ASFV CD2v蛋白胞内域和胞外域,前者的抗原性比后者高,CD2v胞内域作为ASFV免疫学检测技术研究与开发的靶标更具优势。该研究结果对ASFV检测方法的研究与开发具有重要指导意义。

鹅坦布苏病毒E蛋白结构域Ⅲ的原核表达及抗原性分析

【目的】获得鹅坦布苏病毒(GTMUV)E蛋白结构域III的原核表达重组蛋白并明确其免疫原性,为进一步研究其生物学功能及研制亚单位疫苗奠定基础。【方法】根据Gen Bank中GTMUV JS804株E蛋白结构域III的同源基因序列设计1对引物,在其两端加入Flag标签序列和酶切位点,采用PCR扩增GTMUV的E蛋白结构域III基因(EIII),然后与p ET32a原核表达载体连接构建重组表达质粒,转化大肠杆菌BL21(DE3)后用IPTG诱导融合蛋白表达,并以Western blotting鉴定其免疫原性。【结果】PCR扩增获得携带Flag标签序列的EIII基因片段约430 bp,将其插入p ET32a载体可成功构建重组质粒p ET32a-EIII。阳性重组菌经IPTG诱导表达5 h即可得到融合蛋白,分子质量约33.0 k Da,主要以包涵体形式存在。Western blotting鉴定结果显示,融合蛋白与抗Flag标签单克隆抗体、小鼠抗坦布苏病毒多克隆抗体均可发生特异性反应,检测到预期的目的条带。【结论】GTMUV E蛋白结构域Ⅲ能在大肠杆菌中成功诱导表达,且获得的融合蛋白具有良好的免疫原性,可用于研制GTMUV诊断抗原和亚单位疫苗。

马动脉炎病毒GL蛋白主要抗原域的表达及间接ELISA的初步建立

在分析马动脉炎病毒GL蛋白抗原性的基础上,设计一对引物克隆GL蛋白一段抗原性较好的抗原域编码基因。将克隆的基因插入pET-32a的BamHⅠ和XhoⅠ之间构建了GL蛋白主要抗原域原核表达载体pET-GL1。将pET-GL1质粒转化BL(21)宿主菌后,对培养和表达条件进行了优化,实现了EAV GL蛋白主要抗原域的高效表达。免疫印迹试验表明获得的表达产物具有良好的反应原性。应用His.Bind亲和层析柱纯化重组EAV-GL1蛋白,以纯化的重组GL1蛋白作为检测抗原,初步建立了检测马动脉炎病毒抗体的iGL1-ELISA。结果表明,抗原的最佳包被浓度为9.65μg/mL,血清的最佳稀释度为1∶80,阳性标准初步定为:待检血清OD490>0.4,且待检血清OD490/阴性血清OD490>2。应用iGL1-ELISA对马血清样品进行检测,结果表明iGL1-ELISA与病毒中和试验的符合率达到94.1%,与国外同类试剂盒的符合率达到95.6%。

HMGB1对小鼠腹腔巨噬细胞吞噬和I-A/E表达的影响

目的：探讨HMGB1对巨噬细胞免疫功能的影响。方法：梯度浓度HMGB1处理小鼠腹腔巨噬细胞,或将小鼠随机分为生理盐水对照、24h和48h高与低剂量HMGB1注射组,腹腔注射0.2μg或20μg HMGB1,或生理盐水。检测巨噬细胞吞噬功能和I-A/E表达。结果：10μg/L HMGB1刺激6-12h,巨噬细胞吞噬功能较其他剂量组明显增强（P〈0.05或P〈0.01）。HMGB1对培养巨噬细胞I-A/-E表达无影响。高剂量HMGB1攻击小鼠24h,其腹腔巨噬细胞吞噬能力明显降低（P〈0.05）;低剂量HMGB1攻击48h,巨噬细胞I-A/-E表达明显上调（P〈0.05或P〈0.01）。结论：高剂量HMGB1抑制巨噬细胞吞噬功能,低剂量HMGB1增强巨噬细胞免疫功能。

坦布苏病毒E蛋白结构域Ⅰ/Ⅱ蛋白免疫保护效果

为了探讨原核表达的坦布苏病毒E蛋白结构域Ⅰ/Ⅱ蛋白对于坦布苏病毒感染的免疫保护作用,利用IPTG诱导重组大肠杆菌表达坦布苏病毒E蛋白结构域Ⅰ/Ⅱ蛋白,Anti-FLAG M2 Affinity Gel纯化后进行SDS-PAGE和Western blot鉴定。经SDS-PAGE和Western blot鉴定,纯化后坦布苏病毒E蛋白结构域Ⅰ/Ⅱ蛋白仅有单一目的条带。免疫组小鼠血清ELISA效价均达4.67±0.11(lg10)。攻毒保护试验结果表明,免疫组小鼠体质量在攻毒9 d后高于对照组,荧光定量RT-PCR检测结果显示,攻毒后免疫组小鼠脑、肝脏、脾脏组织中坦布苏病毒核酸含量均低于对照组。表明使用原核表达的坦布苏病毒E蛋白结构域Ⅰ/Ⅱ蛋白免疫可诱导产生高水平抗体,并提供良好的免疫保护力,为开发有效的坦布苏病毒亚单位疫苗提供依据。

乙型脑炎病毒E蛋白抗原优势区域的鉴定

流行性乙型脑炎（Japanese Encephalitis，JE）是一种人与动物共患的虫媒病毒性疾病，严重危害着人畜的健康。E蛋白是乙型脑炎病毒（Japanese Encephalitis Virus，JEV）的主要结构蛋白，在病毒的吸附、融合、血凝、细胞趋向性、病毒毒力和诱导保护性免疫反应中起重要作用。为了确定该蛋白的抗原优势区域，本研究设计了3对引物，将E蛋白分成3个大段，分别是EF1（1～291aa）、EF2（292～402aa）和EF3（403-500aa），又将EF1分成4个相互重叠的小片段，分别是EF1-1（1～88aa）、EF1—2（68～155aa）、EF1—3（129～222aa）和EF1—4（202～291aa），将以上基因片段分别克隆到原核表达载体进行GST融合表达。SDS-PAGE电泳鉴定各融合蛋白均获得表达，各表达产物以包涵体的形式存在。通过Western blot分析表明融合蛋白GST-EF1、GST—EF2、GST—EF1—1、GST-EF1-2、GST—EF1—3和GST—EF1～4均能被阳性血清识别。通过ELISA鉴定，GST-EF2反应性最强，GST-EF1反应性比GST-EF2稍弱，而GST-EF3反应性最弱，GST-EF1-1、GST-EF1—2、GST-EF1—3和GST—EF1—4片段融合蛋白反应性与GST—EF1相似。由此本研究鉴定出1-402aa是E蛋白的抗原优势区域，在此区域内包括了12个Cys的保守区及域Ⅰ、域Ⅱ和域Ⅲ3个主要抗原域。E蛋白抗原优势区域的鉴定，为E蛋白抗原表位的鉴定以及针对于E蛋白诊断试剂的开发奠定了基础。

乙型脑炎病毒E蛋白抗原表位多肽序列鉴定及分析

为了对流行性乙型脑炎病毒(JEV)E蛋白抗原表位E19进行核心序列定位,本研究设计了一系列编码相互部分重叠短肽核苷酸序列,原核融合表达后经westernblot分析,确定其抗原表位核心序列为150ENHGNYS156。该表位在乙型脑炎不同基因型的各种病毒株间为高度保守序列;根据JEVE19表位与同一血清群其他黄病毒之间的差异,在同源序列位置设计了系列突变短肽,融合表达后western blot分析的结果表明,其他黄病毒属病毒同源序列不能与抗JEV阳性血清反应。本实验结果表明JEVE蛋白抗原表位E19具有鉴别检测JEV与西尼罗病毒等其它黄病毒的意义。本实验为进一步研究E蛋白结构和功能以及建立乙型脑炎临床鉴别诊断方法奠定了分子生物学基础。

血清LncRNA UCA1、NPASDP4水平与急性脑梗死患者神经功能缺损的关系及对预后的预测价值

目的探讨血清长链非编码核糖核酸尿路上皮癌胚抗原1(LncRNA UCA1)、神经元PAS结构域蛋白4(NPASDP4)水平与急性脑梗死(ACI)患者神经功能缺损的关系及对预后的预测价值。方法选取2021年1月—2023年6月南京大学医学院附属鼓楼医院急诊科收治的ACI患者163例(ACI组),根据美国国立卫生研究院卒中量表(NIHSS)评分分为轻度(n=32)、中度(n=73)、重度缺损亚组(n=58),另选取同期健康体检者65例作为健康对照组。根据ACI患者90 d预后分为不良预后亚组52例、良好预后亚组111例。采用实时荧光定量聚合酶链式反应与酶联免疫吸附法,检测血清LncRNA UCA1与NPASDP4水平。Spearman相关性分析血清LncRNA UCA1、NPASDP4水平与ACI患者NIHSS评分的相关性。多因素Logistic回归分析ACI患者不良预后的因素,受试者工作特征(ROC)曲线分析血清LncRNA UCA1、NPASDP4预测ACI患者不良预后的价值。结果与健康对照组比较,ACI组血清LncRNA UCA1、NPASDP4水平升高(t/P=20.114/<0.001、15.711/<0.001)。血清LncRNA UCA1、NPASDP4水平重度缺损亚组>中度缺损亚组>轻度缺损亚组(F/P=187.914/<0.001、195.031/<0.001)。ACI患者血清LncRNA UCA1、NPASDP4水平与NIHSS评分呈正相关(r/P=0.759/<0.001、0.773/<0.001)。随访90 d,与良好预后亚组比较,不良预后亚组血清LncRNA UCA1、NPASDP4水平升高(t/P=6.963/<0.001、6.515/<0.001)。年龄大、NIHSS评分增加、LncRNA UCA1和NPASDP4升高为ACI患者不良预后的独立危险因素[OR(95%CI)=1.107(1.043~1.176)、1.098(1.049~1.150)、3.479(1.941~6.235)、1.959(1.398~2.745)]。血清LncRNA UCA1、NPASDP4及二者联合预测不良预后的AUC分别为0.777、0.789、0.870,二者联合大于血清LncRNA UCA1、NPASDP4单独预测的AUC(Z/P=3.312/0.001、2.721/0.007)。结论血清LncRNA UCA1表达、NPASDP4水平升高与ACI患者神经功能缺损加重和不良预后密切相关,血清LncRNA UCA1联合NPASDP4水平预测ACI患者不良预后的效能较高。

乙型肝炎病毒e抗原结合蛋白1的克隆及原核表达

目的对应用酵母双杂交技术及生物信息学技术筛选得到的乙型肝炎病毒e抗原结合蛋白1(HBEBP1)进行克隆,并诱导其在大肠埃希菌BL21中的表达。方法应用反转录PCR(RT-PCR)技术,以HepG2细胞mRNA为模板,扩增获得HBEBP1基因片段,连接到pGEM-T载体,双酶切鉴定及测序正确后克隆至原核表达载体pET-32a(+)中,转化大肠埃希菌BL21,IPTG诱导表达以获得HBEBP1融合蛋白,并通过SDS-PAGE及Western blot证实融合蛋白的特异性。结果RT-PCR扩增获得大小为372bp的HBEBP1基因片段,插入至原核表达载体pET-32a(+)中,转化大肠埃希菌BL21,经IPTG诱导后,成功获得大小约为33kD的重组蛋白,Western blot证实其具有良好的特异性。结论构建了pET-32a(+)-HBEBP1原核表达载体,并在大肠埃希菌BL21中诱导表达了HBEBP1融合蛋白,为研究HBEBP1蛋白的免疫原性和生物学特性奠定了基础。