Establishment and Comparison of Two Taq Man Real-time PCR Methods for PCV2

[Objective] In this study, the quantitive detection of PCV2 （porcine circovirus type 2） in vitro was achieved. We aimed to establish two kinds of TaqMan real-time PCR methods based on PCV20RF1 and ORF2 respectively and compare them. [Method] According to the relatively＇conserved sequences of PCV20RF1 and ORF2 registered in GenBank, two pairs of specific primers and TaqMan probes were designed and synthesized. Then the recombinant plasmids containing the whole sequences of PCV20RF1 and ORF2 were constructed to draw the standard curves through optimizing the reaction system and conditions. And thus two kinds of TaqMan real-time PCR detection methods based on the whole sequences of ORF1 and ORF2 respectively were constructed for PCV2. [Result] For the two established standard curves, the Ct values showed a good linear relationship with the loga- rithms of copy numbers of templates （F2〉0.99）. The amplification efficiency ranged from 90% to 110%. The amplifications all had a good repeatability with variation coefficients within groups all less than 5%. Moreover, the amplifications all had a good specificity. When the sequences of porcine parvovirus （PPV）, porcine circovirus type 1 （PCV1）, swine pseudorabies virus （PRV）, porcine reproductive and respiratory syndrome virus （PRRSV） were used as templates, the target sequence was not amplified. The amplifications also had a high sensitivity. The ORF1 detection method could reach 1.0x10T copies/;ul, and the ORF2 detection method could reach 1.0×10^2 copies/μl. The two established real-time PCR detection methods were used to detect the 80 clinical samples respectively. The results showed the magnitudes of 72 amplified samples were basically consistent between the 2 detection methods, while the magnitudes of the other 8 amplified samples were inconsistent. Then the 8 samples were detected with SYBR Green I real-time PCR method established based on the sequence of PCV2-1ike factor P1 by Wen et aL The PCV2-1ike factor P1 was amplified in all the 8 samples, indicating the 8 samples were all infected with PCV2-1ike factor P1. [Conclusion] The ORFl-based detection method has a higher accuracy, and it can be used for the rapid detection of PCV2.

携带分子标记的PCV1-2嵌合病毒的构建及其生物学特性的初步分析

为构建携带分子标记的PCV1-2嵌合病毒,本研究通过基因工程技术将V5标签引入PCV2的ORF2末端,以ORF2-V5替换PCV1的ORF2后克隆于pcDNA3.1(+)载体中,构建pcDNA-PCV1-2m-V5。为检验pcDNA-PCV1-2m-V5的体外感染性,将其转染PK-15细胞后,采用IPMA、RT-PCR等技术进行检测,结果显示:pcDNA-PCV1-2m-V5具有感染性。采集已注射pcDNA-PCV1-2m-V5质粒的小鼠血清接种于PK-15细胞,应用细胞试验、PCR技术、IFA、western blot及电镜等试验对嵌合病毒进行鉴定。结果显示:在小鼠体内拯救出PCV1-2m-V5嵌合病毒,且V5标签的引入能够很好地区分嵌合病毒和亲本病毒产生的Cap蛋白。本实验可为PCV2的感染性DNA (iDNA)疫苗研发提供素材和参考。

稳定表达IL-10的PK-15细胞的构建及其在PCV2增殖中的应用

【目的】研究白细胞介素-10(IL-10)对猪圆环病毒2型(Porcine circovirus type 2,PCV2)复制的影响,筛选PCV2高感染性细胞系和提高PCV2病毒滴度,为后续疫苗的研发及IL-10在PCV2感染中的作用研究提供参考。【方法】利用PCR技术扩增猪IL-10基因,将目的基因与慢病毒表达载体(pCDH-CMV-MCS-EF1-GFP+Puro)进行连接,获得重组质粒pCDH-CMV-IL-10,将其与包装质粒psPAX2和pMD2.G共转染293T细胞进行慢病毒包装。用收集的慢病毒液感染PK-15细胞,经嘌呤霉素筛选后得到细胞株PK-15-IL-10,对照组细胞分别命名为PK-15-pCDH和PK-15。PCV2感染PK-15-IL-10、PK-15-pCDH和PK-15细胞株后,在24、48和72 h分别收集细胞液,利用CCK-8检测细胞活力。利用实时荧光定量PCR和Western blotting检测IL-10基因的表达水平和PCV2的复制情况;利用间接免疫荧光试验(IFA)观察PCV2在细胞中的复制情况及测定PCV2的病毒滴度(TCID50)。【结果】试验成功构建了重组质粒pCDH-CMV-IL-10,将其与包装质粒psPAX2和pMD2.G共转染293T细胞后,48 h时细胞状态最好,荧光最强。分别收集共转染48和72 h的慢病毒液上清感染PK-15细胞,pCDH-CMV-IL-10组的荧光最强,将其在嘌呤霉素浓度为2.5μg/mL的完全培养基中继续培养,获得仍有绿色荧光的稳转细胞株。实时荧光定量PCR和Western blotting检测发现,IL-10基因在pCDH-IL-10细胞株中的表达量明显高于对照组PK-15-pCDH和PK-15,PCV2的拷贝数增加了4倍,复制能力增强,且将病毒稀释连续传3代后,PK-15-IL-10细胞中的PCV2极显著高于PK-15细胞(P<0.01)。细胞增殖试验表明,猪IL-10基因在细胞中过表达对细胞活力无明显影响;IFA结果表明,PK-15-IL-10细胞中的荧光比PK-15细胞更强,PCV2在PK-15-IL-10细胞中的TCID50在感染后48 h极显著高于PK-15细胞(P<0.01)。【结论】本研究成功构建了pCDH-CMV-IL-10的慢病毒表达载体,并利用其感染PK-15细胞,继续培养后筛选出过表达IL-10的PK-15-IL-10细胞株,用PCV2感染该细胞株能促进PCV2在PK-15细胞中的复制。本试验结果为后期疫苗研究提供了参考,为进一步研究IL-10对PCV2在PK-15细胞中复制的影响奠定了基础。

Development of a Loop-Mediated Isothermal Amplification Assay for Porcine Circovirus Type 2

In this study, the loop-mediated isothermal amplification (LAMP) method was used to develop a rapid and simple detection system for porcine circovirus type 2 (PCV2). According to the PCV2 sequences published in GenBank, multiple LAMP primers were designed targeting conserved sequences of PCV2. Using the DNA extracted from PCV2 isolates HUN-09 and SD-09 as the template, LAMP reactions in a PCV2 LAMP system was performed, the amplification products were detected by adding SYBR Green I and could be observed directly by the naked eye. The results showed highly-efficient and specific amplification in 30 min at 63°C with a LAMP real-time turbidimeter. Furthermore, PCV2 DNA templates, with a detection limit of 5.5×10-5 ng of nucleic acid, indicated that this assay was highly sensitive. The results obtained with the naked eye after SYBR Green I staining were consistent with those detected by the real-time turbidimeter, showing the potential simplicity of interpretation of the assay results. The LAMP assay appeared to have greater accuracy than PCR and virus isolation for the analysis of 18 clinical samples. In addition it offers higher specificity and sensitivity, shorter reaction times and simpler procedures than the currently available methods of PCV2 detection. It is therefore a promising tool for the effective and efficient detection of PCV2.

Specific activation of 2'-5'oligoadenylate synthetase gene promoter by hepatitis C virus-core protein:A potential for developing hepatitis C virus targeting gene therapy

AIM： TO examine whether 2＇-5＇oligoadenylate synthetase （OAS） gene promoter can be specifically activated by hepatitis C virus （HCV）-core protein. METHODS： Human embryo hepatic cell line L02 was transfected with pcDNA3.1-core plasmid and selected by G418. Expression of HCV-core was detected by reverse transcription polymerase chain reaction and Western blotting. The OAS promoter sequence was amplified from the genomic DNA and inserted into pGL3-basic vector. The resultant pGL3-OAS-Luci plasmid was transiently transfected into L02/core cells and luciferase activity was assayed. I^ESULTS： L02/core cell line stably expressing HCV- core protein was established. The pGL3-OAS-Luci construct exhibited significant transcriptional activity in the L02/core cells but not in the L02 cells. CONCLUSION： HCV-core protein activates the OAS gene promoter specifically and effectively. Utilization of OAS gene promoter would be an ideal strategy for developing HCV-specific gene therapy.

Expression of co-stimulatory molecules B7-2 and PD-L1 on peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection

Objective： To explore the roles of the expression of the co-stimulatory molecule, B7-2, and the co-inhibitory molecule, PD-L1, on peripheral blood mononuclear cells in the mechanism of immunotolerance in chronic hepatitis B virus infection. Methods： Thirty HBV infected patients in the immunoreactive phase and 20 patients in the immunotolerant phase were enrolled in the study, while 20 healthy volunteers were used as controls. RT- PCR and real-time PCR methods were used to detect the expression levels of B7-2 and PD-L1 mRNA in peripheral blood mononuclear cells in chronic HBV infected patients. Results： The B7-2 expression in irnrnunoreactive and immunotolerant patients was significantly lower than that in the controls （P all 〈 0.01 ）; B7-2 expression in immunoreactive patients was significantly lower than in immunotolerant patients （P 〈 0.01）. PD-L1 expression in irnmunoreactive patients and immunotolerant patients was significantly higher than that in normal controls （P all 〈 0.01）. The PD-L1/BT-2 ratios in immunoreactive and immunotolerant patients were significantly higher than that of the healthy controls （P all 〈 0.01）; the PD-L1/ B7-2 ratio was significantly higher in the immunoreactive patients than in the immunotolerant patients （P 〈 0.01）. Conclusion： In chronic HBV infection, changes in the expression of co-stimulatory and co-inhibitory molecules imply a protective adjustment against the patient＇ s immune response that may result in increased immunotolerance and persistent HBV infection.

A retrospective investigation on the phenotype and stability of the E-protein gene in Japanese Encephalitis (JE) virus strain SA14-14-2 used live-attenuated JE vaccine

To detect retrospectively the phenotype and stability of the E-protein gene in Japanese Encephalitis （JE） virus strain SA14-14-2 used in the live-attenuated JE vaccine prepears, the viral titer was titrated by plaque formation in BHK-21 cell cultures, and the neuro-virulence of viruses was assayed in mice with body weight of 12-14 g by intracerebral inoculation. Meanwhile, the total RNA of virus gene was extracted and amplified by RT-PCR with the designed primers, and then it was purified and cloned to the expression vector pGEM-T. The recombinant plasmid was purified and sequenced. It was found that the loss of viral titer of vaccines stored in -20℃ for longer than 10 years was less than 0.5 Lg PFU/ml. No mice inoculated intracerebrally showed signs of illness or even death. The size of plagues of the vaccine virus remained to be small, and the E genes of primary virus seed SA14-14-2 and the vaccines prepared at different years （1987-2001） were unchanged, in- cluding the 8 critical amino acid sites which were different from the parent wild virus strain SA14 and the related neuro-virulence. These results indicate that the genotypic and biological characteristics of the attenuated JE virus strain SA14-14-2 and its vaccines sion noted. prepared are quite stable without any reversion noted.

猪圆环病毒2型感染对猪小肠上皮细胞Claudin-1蛋白和闭锁小带蛋白-1基因mRNA表达的影响

紧密连接在维持肠道黏膜完整性和免疫系统正常发挥功能中作用重大。【目的】旨在探讨猪圆环病毒2型(PCV2)感染对猪小肠上皮细胞(IPEC)紧密连接的影响。【方法】利用基因克隆获得Claudin-1蛋白和闭锁小带蛋白-1 (ZO-1)基因的重组质粒并建立荧光定量RT-PCR标准曲线;利用所建立的方法检测PCV2感染的IPEC中Claudin-1蛋白和闭锁小带蛋白-1mRNA的动态变化。【结果】构建的两种紧密连接蛋白基因的重组质粒荧光定量RT-PCR标准曲线线性关系良好,相关系数均达0.99以上。PCV2感染的IPEC中Claudin-1蛋白和ZO-1mRNA表达在4、12、24、48、72h均显著下降。【结论】PCV2感染可抑制猪小肠上皮细胞紧密连接蛋白相关基因的表达,破坏细胞间的紧密连接,增加肠道通透性。

Study on pharmacodynamics of recombinant interferon α-2b suppository

Objective To investigate the antiviral activity of recombinant interferonα-2b suppository(IFNα-2b)in vivo and in vitro.Methods The cytopathic-effect inhibition assay was applied in this study to investigate the antiviral activity of this drug as well as yingtelong and axiluowei as positive control.The guinea pig model of vaginitis and skin infection caused by HSV-2 infection were established,treated with IFNα-2b suppository at dosages of 60000、180000、540000 IU,using IFNα-2b injection 180000 IU·kg-1 as controls.Score the pathological changes of appearance and skin,the virus activities of vaginal secretion and tissue sections of viginae were assayed after treatment.Results The TD50 of IFN α-2b and yingtelong for Vero cells was(>100)μg·mL-1 and(>100000)IU·mL-1,respectively.The IC50 of IFN α-2b and yingtelong and axiluowei for Herpes virus type 1 was(0.29±0.08)μg·mL-1 and(185.0±28.8)IU·mL-1 and(0.19±0.03)μg·mL-1,respectively.The mean scores for vaginal and skin lesion of the treated groups were lower than those of untreated group.Among these concentrations,the IFNα-2b suppository of 540000 IU·kg-1 group.Showed highest anti-viral activity.The virus activity in vaginal secretion of treated group was lower than that of untreated group too(P<0.01 or P<0.05).Tissue sections of viginae after treatment with IFNα-2b suppository showed significantly therapeutical effects on the degrees of vaginal lesion.At the same dosage,The anti-HSV activity of IFNα-2b suppository was also compared with IFNα-2b injection,the results showed that the activity of suppository of 540000 IU·kg-1 group was similar to that of the injection.Conclusions The IFNα-2b suppository has anti-viruses function both in vivo and in vitro.

Effects of anti-HPV bioprotein dressing combined with interferon α-2b therapy on the malignant molecule expression in patients with CINⅢ complicated by high-risk HPV positive

Objective: To study the effects of anti-HPV bioprotein dressing combined with interferon α-2b therapy on the malignant molecule expression in patients with cervical intraepithelial neoplasia (CIN) Ⅲ complicated by high-risk HPV positive. Methods: Patients who were diagnosed with CINⅢ and high-risk HPV positive and underwent conization in the 3201 Hospital Affiliated to Xi'an Jiaotong University between June 2014 and February 2017 were selected and randomly divided into the observation group who received preoperative anti-HPV bioprotein dressing combined with interferon α-2b therapy and the control group who received no special treatment. CIN lesion was collected to determine the expression of pro-proliferation molecules, pro-apoptosis molecules and epithelial-mesenchymal transition molecules. Results: Rsf1, Piwil2, TOPK, p38MAPK, ERK, Snail, Twist, N-cadherin and Vimentin mRNA expression in cervical intraepithelial neoplasia lesions of observation group were greatly lower than those of control group whereas LRIG3, SARI, IEX-1, FHIT and E-cadherin mRNA expression were greatly higher than those of control group. Conclusion: Anti-HPV bioprotein dressing combined with interferon α-2b therapy can inhibit the proliferation and invasive growth of tumor cells in patients with CINⅢ complicated by high-risk HPV positive.

中心静脉-动脉血二氧化碳分压差对血液净化治疗顽固性感染性休克患者的预测价值

目的：探讨中心静脉－动脉血二氧化碳分压差（ Pcv－aCO2）对血液净化治疗顽固性感染性休克的预测价值。方法采用前瞻性观察研究方法，选择2011－06～2014－06在葛洲坝中心医院重症医学科治疗的55例接受血液净化治疗的顽固性感染性休克患者，将血液净化治疗48 h后去甲肾上腺素（NE）剂量及血乳酸（Lac）下降≥30％的患者定义为治疗有反应，反之为治疗无反应，对应将患者分为有反应组及无反应组。记录两组患者在血液净化治疗前和治疗后48 h循环灌注指标，包括Pcv－aCO2、中心静脉血氧饱和度（ ScvO2）、血Lac；观察器官功能指标，包括血肌酐（Cr）、N末端脑钠肽前体（NT－proBNP）、血清降钙素原（PCT）、氧合指数（PaO2／FiO2）及急性生理学与慢性健康状况评分系统Ⅱ（ APACHEⅡ）评分、序贯器官衰竭评分系统（ SOFA）评分。通过Logistic回归分析，评价各指标与治疗反应的关系，通过受试者工作特征（ ROC）曲线评估各个参数对治疗反应的预测能力。结果与治疗有反应组比较，治疗无反应组Pcv－aCO2、PCT明显升高[Pcv－aCO2（mm Hg）：9（8，12）比8（6，8），Z＝－4．551，P＝0．000；PCT（ng／mL）：6．0（4．0，9．0）比4．5（3．0，6．0），Z＝－2．442，P＝0．015]，7 d SOFA评分变化[ΔSOFA （D1～D7）评分]明显恶化[ΔSOFA （D1～D7）评分（分）：－1（－2，0）比3（2，4），Z＝－3．743，P＝0．000]，住院病死率比有反应组升高[60.87％（14／23）比25．00％（8／32），P＝0．007]。相关分析显示，入组48 h后Pcv－aCO2与血Lac（r＝0．494，P＝0．000）呈明显正相关。对单因素分析中有统计学意义的 Pcv－aCO2和PCT进行多因素Logistic回归分析发现，Pcv－aCO2水平升高[ OR＝3．198，95％ CI 1．487～6.877，P＝0．003]是血液净化治疗反应差的独立危险因素。 Pcv－aCO2预测血液净化治疗无反应的ROC曲线下面积（ AUC）为0．855，最佳临界值为8 mm Hg 时，敏感度为69．57％，特异度为84.37％，高于血清PCT、血Lac及ScvO2的预测价值。联合Pcv－aCO2和血清PCT共同预测治疗反应，AUC为0．873，敏感度为73．91％，特异度为93．75％。结论 Pcv－aCO2可预测血液净化治疗顽固性感染性休克的治疗反应。

中心静脉-动脉血二氧化碳分压差值评估严重脓毒症患者预后的临床研究

目的 探讨中心静脉-动脉血二氧化碳分压差值（Pcv-aCO2）在评估严重脓毒症患者预后中的临床价值.方法收集入住我院ICU 96例经过早期液体复苏治疗后中心静脉血氧饱和度（ScvO2）≥70%的严重脓毒症患者的APACHEⅡ评分、ScvO2、6 h Pcv-aCO2、6 h动脉血乳酸清除率和预后的相关资料.按预后不同将患者分为存活组（n=61）和死亡组（n=35）;以Pcv-aCO2 6 mm Hg为界分为高Pcv-aCO2组（≥6 mm Hg,n=40）和低Pcv-aCO2组（〈6 mm Hg,n=56）,比较存活组与死亡组、高Pcv-aCO2组与低Pcv-aCO2组之间相关数值的差异.结果 各组治疗前APACHEⅡ评分、ScvO2、动脉血乳酸比较差异均无统计学意义（P〉0.05 ）.存活组6 h Pcv-aCO2（3.15±1.54） mm Hg,明显低于死亡组[（8.34±1.89）mm Hg,P〈0.01];低Pcv-aCO2组病死率（28.57%）明显低于高Pcv-aCO2组（47.50%,P〈0.05）.存活组和低Pcv-aCO2组6 h血乳酸清除率（26.54±11.21）%和（28.16±12.39）%,明显高于死亡组[（14.96±10.93）%]和高Pcv-aCO2组[（13.82±13.54）%,均P〈0.01].6 h Pcv-aCO2与6 h血乳酸清除率呈负相关（r=-0.719,P〈0.01）.结论早期Pcv-aCO2可作为评估严重脓毒症患者预后的一个指标.

提高猪圆环病毒2型产量的方法比较

为了获得较高的病毒滴度,降低疫苗成本,选用4种刺激剂:二磷酸氯喹(CQ)、刀豆素(Con A)、D-氨基葡萄糖(D-G)和β-甲基-环糊精(MβCD),采用单独刺激和联合刺激感染PCV2的PK-15细胞,研究PCV2增殖情况。结果显示,MβCD和D-G单独作用均能显著促进PCV2的感染和复制,且效果优于另外2种单独作用;采用3 mmol/L D-氨基葡萄糖和2.5 mmol/L MβCD联合作用方法,在病毒5次传代期间病毒滴度显著高于单独作用组,最高滴度达到107.3TCID50/m L,该法有助于提高PCV2复制效率,提高疫苗的产量。

Identification of African swine fever virus MGF505-2R as a potent inhibitor of innate immunity in vitro

African swine fever(ASF)is etiologically an acute,highly contagious and hemorrhagic disease caused by African swine fever virus(ASFV).Due to its genetic variation and phenotypic diversity,until now,no efficient commercial vaccines or therapeutic options are available.The ASFV genome contains a conserved middle region and two flexible ends that code for five multigene families(MGFs),while the biological functions of the MGFs are not fully characterized.Here,ASFV MGF505-2R-deficient mutant ASFV-Δ2R was constructed based on a highly virulent genotype II field isolate ASFV CN/GS/2018 currently circulating in China.Transcriptomic profiling demonstrated that ASFV-Δ2R was capable of inducing a larger number of differentially expressed genes(DEGs)compared with ASFV CN/GS/2018.Hierarchical clustering of up-regulated DEGs revealed that ASFV-Δ2R induced the most dramatic expression of interferon-related genes and inflammatory and innate immune genes,as further validated by RT-qPCR.The GO and KEGG pathway analysis identified significantly enriched pathways involved in pathogen recognition and innate antiviral immunity.Conversely,pharmacological activation of those antiviral immune responses by exogenous cytokines,including type I/II IFNs,TNF-αand IL-1β,exerted combinatory effects and synergized in antiviral capacity against ASFV replication.Collectively,MGF505-2R is a newly identified inhibitor of innate immunity potentially implicated in immune evasion.

Microalbuminuria in hepatitis C-genotype 4:Effect of pegylated interferon and ribavirin

AIM:To study the relation between hepatitis C virus (HCV) genotype 4 and microalbuminuria and renal impairment in relation to hepatic histology, and viremia in the absence of cryoglobulinemia, and to examine the effect of treatment on microalbuminuria.METHODS: Three hundred subjects, including 233 HCV genotype-4 infected patients, were tested for cryoglobulinemia, microalbuminuria, albumin creatinine ratio (ACR), urea, creatinine, and estimated glomerular filtration rate (eGFR). The parameters were measured again in the HCV patients after 48 wk of treatment with pegylated interferon and ribavirin.RESULTS: Significantly higher levels of microalbumin- uria were detected in HCV-positive patients compared to HCV-negative controls (median 9.5 vs 5.9, respectively, Kruskal-Wallis P=0.017). Log microalbuminuria was significantly correlated with hepatic inflammation (r=0.13, P=0.036) and f ibrosis (r=0.12, P=0.061), but not with viral load (r=-0.03, P=0.610), or alanine transaminase (r=-0.03, P=0.617). Diabetes mellitus neither significantly moderated (χ2=0.13, P=0.720), nor mediated (Sobel test P=0.49) the HCV effect. HCV status was signifi cantly associated with log microalbu-minuria (χ2=4.97, P=0.026), adjusting for age, gender, diabetes, cryoglobulinemia, urea and creatinine. A positive HCV status was not significantly associated with low eGFR (<60 mL/min every 1.73 m2) [odds ratio (OR): 0.5, 95% confidence interval (CI):0.2-1.4], nor with high ACR (OR: 1.7, 95% CI:0.7-4.1). End-of-treatment response (ETR) was achieved in 51.9% of patients. Individuals with ETR had significantly lower microalbuminuria post-treatment (χ2=8.19, P=0.004).CONCLUSION: HCV affected the development of microalbuminuria independent of diabetes or cryoglobulinemia. Combination therapy of pegylated interferon-ribavirin had a positive effect in reducing microalbuminuria.

PCV1-2m嵌合病毒TaqMan荧光定量PCR检测方法的建立及其初步应用

为确定感染性克隆质粒免疫小鼠拯救获得的病毒量与诱导抗体之间的关系,以选择最佳免疫剂量,本研究建立了一种快速、灵敏的TaqMan荧光定量PCR检测方法。根据pcDNA3.1(+)-PCV1-2m-V5质粒的ORF2和V5标签序列设计特异性引物和探针,并将该质粒作为阳性标准品,优化荧光定量PCR条件后,按10倍倍比稀释,建立标准曲线,进行灵敏性、特异性和稳定性验证;而后,应用该方法对免疫不同质粒浓度的6组小鼠,分别在免疫后1~9周进行病毒血症检测;同时,应用ELISA方法分别对PCV2抗体滴度进行检测。结果表明,试验建立的荧光定量PCR方法具有良好的灵敏性、特异性和稳定性,检测范围可达1.29×10^1~1.29×10^9拷贝/μL;病毒血症可持续至第5周,抗体可维持至第8周。通过分析抗体滴度变化与病毒载量消长关系,确定使用200μg作为小鼠的最佳免疫剂量。本试验为感染性克隆质粒进一步在本体动物(猪)体内评估免疫效果奠定基础。

嵌合猪圆环病毒的构建

【目的】为了构建猪圆环病毒1型(PCV1)和猪圆环病毒2型(PCV2)的嵌合病毒,并为PCV2疫苗研究奠定基础。【方法】以PCV1基因组为骨架,将其衣壳基因替换为PCV2衣壳基因,来构建嵌合猪圆环病毒(PCV1-2)DNA克隆,将PCV1-2DNA克隆转染PK-15细胞以获得拯救病毒PCV1-2,并测定PCV1-2在PK-15细胞中的增殖特性。【结果】酶切和序列测定显示成功构建出PCV1-2DNA克隆;免疫荧光试验和PCR检测显示成功获得拯救病毒PCV1-2,其效价达到106.0 TCID50/mL以上;一步生长曲线显示PCV1-2在PK-15细胞中的增殖特性与其亲本病毒近似。【结论】成功构建了1种具有较高体外增殖能力的嵌合猪圆环病毒。

检测猪繁殖与呼吸综合征病毒和猪圆环病毒的二重荧光LAMP方法的建立

建立一种二重荧光LAMP的检测猪繁殖与呼吸综合征病毒(PRRSV)和猪圆环病毒(PCV)的快速诊断技术。根据已发表的PRRSV NSP2基因和PCV2 ORF2基因序列保守区域,分别设计并合成了两组针对PRRSV和PCV2序列的特异性引物和两条探针,两条探针分别标记不同的荧光基团,PRRSV-Probe 5’端标记FAM荧光基团,3’端标记BHQ1淬灭基团,PCV-Probe 5’端标记CY5.5荧光基团,3’端标记BHQ2淬灭基团。对组成反应体系中的引物、探针以及反应试剂进行优化,建立了二重荧光LAMP检测PRRSV和PCV2方法。对建立的方法进行特异性和敏感性测试,并用模拟混合样品和临床样品进行检测验证。结果显示,本研究建立的方法可以鉴别区分PRRSV和PCV2,特异性试验表明该方法只检测出PRRSV或PCV2,且与参试的对照病毒无交叉反应,特异性好。敏感性测试表明该方法最低检测PRRSV或PCV为100拷贝,敏感性好。对临床样品的检测,结果与荧光定量PCR方法检测结果一致。本研究建立的PRRSV和PCV2二重荧光LAMP检测方法,具有良好的特异性和敏感性,可用于临床样品中检测PRRSV和PCV2。

FoxJ1 inhibits African swine fever virus replication and viral S273R protein decreases the expression of FoxJ1 to impair its antiviral effect

African swine fever(ASF)is a highly pathogenic swine infectious disease that affects domestic pigs and wild boar,which is caused by the African swine fever virus(ASFV).ASF has caused huge economic losses to the pig industry and seriously threatens global food security and livestock health.To date,there is no safe and effective commercial vaccine against ASF.Unveiling the underlying mechanisms of ASFV-host interplay is critical for developing effective vaccines and drugs against ASFV.In the present study,RNA-sequencing,RT-qPCR and Western blotting analysis revealed that the transcriptional and protein levels of the host factor FoxJ1 were significantly down-regulated in primary porcine alveolar macrophages(PAMs)infected by ASFV.RT-qPCR analysis showed that overexpression of FoxJ1 upregulated the transcription of type I interferon and interferon stimulating genes(ISGs)induced by poly(dA:dT).FoxJ1 revealed a function to positively regulate innate immune response,therefore,suppressing the replication of ASFV.In addition,Western blotting analysis indicated that FoxJ1 degraded ASFV MGF505-2R and E165R proteins through autophagy pathway.Meanwhile,RT-qPCR and Western blotting analysis showed that ASFV S273R inhibited the expression of FoxJ1.Altogether,we determined that FoxJ1 plays an antiviral role against ASFV replication,and ASFV protein impairs FoxJ1-mediated antiviral effect by degradation of FoxJ1.Our findings provide new insights into the antiviral function of FoxJ1,which might help design antiviral drugs or vaccines against ASFV infection.

Screening of Fungi from Chinese Medical Plants for Anti-Human Immunodeficiency Virus Type 1 Activity

In order to Isolate anti-human Immunodeflclency virus （HIV） agents from natural products, 97 ethanollc extracts of 90 fungi were tested for their Inhibitory activity on HIV-1. Most of the extracts tested were relatively non-toxic to human lymphocytic MT-4 cells, but extracts of some fungi exhibited potent antl-HIV activity In an in vitro 3-（4, 5-dlmethyl-2 thlazoyl）-2,5-dlphenyl-2H-tetrazollum bromide assay with a selectivity Index greater than 3. Most fungi were Isolated from Dendrobium sp. and Taxus sp.