免疫抑制剂地塞米松可明显延长乙型肝炎病毒抗原在水动力法转染HBV小鼠模型中的表达

建立基于高压水动力法的乙型肝炎病毒(HBV)转染小鼠模型,并进一步建立和优化乙肝动物模型研究方法。首先构建了含腺相关病毒倒转末端重复序列元件与包含1.3个拷贝HBV基因组(ayw亚型)的HBV表达质粒(pAAV-HBV1.3);并将pAAV-HBV1.3质粒经高压水动力法尾静脉注射C57BL/6小鼠,不同时间点采集血液和肝组织标本,ELISA检测血清HBsAg、HBeAg表达;Real-time PCR检测血清及肝组织病毒载量;HE染色、免疫组化染色检测肝组织病理学改变及病毒抗原在肝组织中的定位及表达;最后采用免疫抑制剂地塞米松注射液(DEX)腹腔注射小鼠,建立免疫功能抑制小鼠模型,在此基础上制备乙肝病毒转染小鼠模型,并进行血清HBsAg、HBeAg检测。结果是正常免疫状态下,小鼠转染pAAV-HBV1.3 10d时血清及肝组织HBV相关抗原阳性,30d后HBV相关抗原检测阴性,但30d和60d血清及肝组织病毒载量检测均为阳性,且与对照组差异显著(P0.01,P0.05);经地塞米松注射后处于免疫抑制状态下的高压水动力法建立的乙肝病毒转染小鼠,则在60d仍可检测到HBsAg、HBeAg的表达。以上结果表明通过高压水动力法建立了急性乙肝小鼠模型,通过抑制小鼠免疫状态,可延长病毒在小鼠体内存留时间。该模型建立为HBV疫苗评价、药物开发及乙肝相关致病机理研究奠定了基础。     

乙型肝炎病毒外膜大蛋白和HBVDNA血清学诊断价值

目的探讨乙型肝炎病毒外膜大蛋白和HBV-DNA在乙肝患者中的血清学诊断价值。方法收集乙肝两对半(HBV-M)中HBsAg阳性血清标本260例作为乙肝研究组,乙肝两对半(HBV-M)阴性血清标本100例作为正常对照组;在不同乙肝模式中采用酶联免疫吸附试验(ELISA)检测血清HBV-LP和Pre-S1,荧光定量PCR检测HBV DNA;比较HBeAg血清中HBV-LP与HBV-DNA和不同HBV-DNA拷贝数的条件下HBV-LP与HBV-DNA剂量关系。结果HBsAg阳性血清中HBV-LP、HBV-DNA和Pre-S1阳性率分别为68.46%、63.08%和24.23%;HBeAg阳性标本中HBV-LP、HBV-DNA和Pre-S1阳性率分别为94.87%、94.87%和79.49%;HBeAg阴性标本中HBV-LP、HBV-DNA和Pre-S1阳性率分别为62.64%、49.45%和0.55%,HBV-LP和HBV-DNA二者检出一致率为67.03%[(50+72)/182];HBV-LP吸光度(A值)与HBV DNA呈正相关。结论HBV-LP与HBV-DNA在HBeAg阳性血清中代表病毒复制具有较高检出一致率;HBV-LP与HBV-DNA在HBeAg阴性血清中具有较大的差异性,HBV-DNA阴性血清中检测HBV-LP反应乙肝病毒复制对乙肝抗病毒治疗更有重要意义;HBV DNA拷贝数与HBV-LP含量呈正相关系。     

从乙型肝炎病毒表面抗原阳性母亲流产的胎儿查出乙型肝炎病毒标志

应用Southern blot杂交试验检测HBsAg及HBeAg均阳性母亲流产的9例胎儿肝细胞中HBV DNA的存在状态,并与其HBV血清学、免疫电镜及肝脏免疫组织化学的结果相比较。结果在3例胎肝高分子DNA中检出了整合的HBV DNA顺序,且此3例HBV DNA整合到胎肝细胞基因组并无特定部位,提示为随机整合。3例中2例的血清及肝匀浆都检出HBsAg颗粒,其胎肝细胞胞浆HBsAg也阳性;另1例受HBV感染的唯一标志是在胎肝细胞中存在着整合的HBVDNA。此外,另1例则仅胎肝细胞中HBsAg阳性而无整合的HBV DNA。在胎肝细胞中检出整合的HBV DNA进一步证实HBV子宫内传播途径的存在。     

比较不同血清型AAV携带HBV基因组建立乙肝小鼠模型效果

近年来,用8型腺相关病毒携带1.3拷贝HBV(Hepatitis B virus)基因组建立的HBV持续感染小鼠模型受到越来越多的关注。本研究比较了除AAV8之外的其他4种血清型重组腺相关病毒(Recombinant adeno-associated virus,rAAV)建立乙肝小鼠模型效果。首先,将携带1.3拷贝ayw亚型HBV基因组的1型、2型、5型、8型、9型腺相关病毒分别以1×10~(11) vg/只(Viral genome,vg)的剂量尾静脉注射C57BL/6J小鼠;利用ELISA方法监测小鼠血清中HBeAg和HBsAg表达水平;用定量PCR方法检测小鼠血清和肝脏中HBV DNA拷贝数;用免疫组化方法检测小鼠肝脏中HBc Ag的表达;用HE染色检测小鼠肝脏病理变化。结果显示,在持续8周中,5组小鼠血清中都检测到HBeAg和HBsAg的表达,血清和肝脏中均检测到HBV DNA的存在。HBeAg、HBsAg、HBV DNA表达水平高低依次为AAV8AAV9AAV1AAV5AAV2。5组小鼠用免疫组化方法都检测到肝脏中HBcAg表达,HE染色病理检测均观察到不同程度的肝损伤。本研究扩大了能用于建立乙肝小鼠持续感染模型可选择的AAV载体种类,发现虽然AAV1、2、5、9的建模效果不如AAV8,但它们都可以介导建立持续感染的乙肝小鼠模型,建模效果依次为AAV8AAV9AAV1AAV5AAV2。其中AAV9介导的建模效果与AAV8载体最为接近,可以替代AAV8载体用于有效地建立HBV持续感染的小鼠模型。     

乙肝孕妇宫内感染监测与HBVM评估

目的监测孕妇产前感染HBV与宫内感染情况,评估乙肝孕妇血清中乙肝血清标志物（HBVM）对宫内感染HBV的风险大小,指导育龄妇女早期预防宫内感染。方法采用ELISA法检测孕妇血清乙肝标志物（HBVM）6项,即HBsAg、HBsAb、HBeAg、HBeAb、HBcAb与Pre-S1;筛选乙肝携带者采用实时荧光定量PCR法进行HBV DNA检测;应用ELISA法对新生儿24h内（免疫接种前）外周血HBsAg、Pre-S1和、HBeAg进行检测。结果1002例孕妇中乙肝感染率为10．6％,106例乙肝孕妇宫内感染34例,宫内感染率为32％。HBeAg（＋）者宫内感染风险率最高为77％,HBV DNA（＋）与Pre-S1（＋）次之。HBV DNA（-）宫内感染风险率最低为2％,HBeAg（-）与Pre-S1（-）次之。结论乙肝孕妇宫内感染率较高;HBeAg（＋）孕妇宫内感染HBV风险最高,可作为育龄妇女采取措施积极预防宫内感染的指标。HBV DNA（-）宫内感染率最低,可作为育龄妇女宫内安全的评估指标。Pre-S1是宫内感染的有利补充指标。     

激活补体类乙型肝炎病毒表面抗原(HBsAg)循环免疫复合物在急慢性乙型肝炎中的意义

激活补体类HBsAg循环免疫复合物(HBsAg/C3-CIC )的检出率,与HBV复制标志的关系,在急慢性乙型肝炎病毒感染中表现不同。在慢性肝病(包括慢性迁延性乙型肝炎、慢性活动性乙型肝炎、乙型肝炎后肝硬化和HBV感染指标阳性的原发性肝癌)患者中,HBeAg阳性者,其HBsAg/C3-CIC的检出率显著高于HBeAg阴性者,且随HBeAgS/N值的升高而增加。在由HBV e系统组合成的四种模式中,单纯HBeAg阳性模式的检出率显著高于其它三种模式;在多聚白蛋白受体(PHSAr)阳性者中检出率显著高于PHSAr阴性者。而急性乙型肝炎(AH)的HBsAg/C3-CIC检出率无类似差异。这些结果提示,HBsAg/C3-CIC在HBV感染的急慢性肝病中具有不同的病理生理意义。     

乙肝病毒标志物在胎儿和胎盘组织中的表达及其与 HBV母婴传播关系的研究

目的通过对乙肝阳性产妇外周血、胎儿及胎儿附属物进行乙肝病毒标志物的检测,探讨HBV宫内感染发生的机制。方法通过ELISA法及实时荧光定量PCR法检测血清标本中HBV标志物及HBV DNA水平;通过对组织标本的免疫组织化学染色检测组织中HBV标志物的表达。结果胎儿脐血HBV DNA水平与母血HBV DNA水平相关,母血HBV DNA高水平(≥107copy/mL)时脐血HBV DNA阳性率明显增高,P<0.05。胎儿脐血HBV DNA水平显著低于母血HBV DNA水平,P<0.05。胎盘组织可见HBsAg免疫组织化学染色阳性,但未发现HBcAg染色阳性。在引产胎儿胎肝和胎肾组织中发现HBsAg和/或HBcAg免疫组织化学染色阳性细胞。结论母亲HBV DNA高水平是发生HBV宫内感染的高危因素。脐血HBV DNA阳性是判断HBV宫内感染的相关指标;HBV可能通过胎盘感染的途径由母体进入胎儿体内,并可能在胎儿体内定位和复制,这可能是导致HBV宫内感染的原因。     

利用乙型肝炎病毒共价闭合环状DNA构建慢性乙型肝炎病毒感染的小鼠模型

目的通过水动力法注射乙型肝炎病毒(HBV)共价闭合环状DNA(cccDNA)构建C57BL/6小鼠慢性乙型肝炎病毒感染的模型。方法取29只C57BL/6小鼠,分为实验组、对照组和空白组,应用水动力法分别注射HBV cccDNA、pAAV-HBV1.2及等渗盐水,于注射后收集不同时间点的血清和肝组织。利用放射免疫法检测血清样本中乙型肝炎病毒表面抗原(HBsAg)和乙型肝炎病毒e抗原(HBeAg);荧光定量PCR检测血清和肝组织中HBV DNA拷贝数;免疫组织化学法检测肝组织中HBsAg和乙型肝炎病毒核心抗原(HBc Ag)的表达;苏木精-伊红(HE)染色观察肝组织病理变化;使用SPSS 17.0对数据进行统计学分析。结果实验组HBsAg和HBeAg表达均呈现4个上升-下降曲线:HBsAg峰值分别出现在第3天、第3周、第7周和第9周;HBeAg峰值分别出现在第1天、第1周、第4周和第10周。对照组HBsAg和HBeAg表达分别呈现2个或3个明显的峰:HBsAg峰值分别出现在第3天和第8周;HBeAg峰值分别出现在第1天、第3周和第10周。空白组未检测出HBsAg和HBeAg。实验组HBV DNA拷贝数高于对照组的拷贝数(P<0.01);肝组织中HBV DNA拷贝数高于同期血清中的拷贝数(P<0.01);实验组和对照组的肝组织中均有HBsAg和HBc Ag的表达;实验组与对照组出现肝脏细胞炎症、肝细胞纤维化、肝细胞坏死等病理变化,而空白组正常。结论利用水动力法向C57BL/6小鼠体内转入HBV cccDNA,成功建立了慢性乙型肝炎病毒感染的小鼠模型,与对照组比较,新建立的小鼠乙肝模型具有更高的HBV表达,动物模型为研究乙型肝炎病毒HBV cccDNA的感染及其引起肝损伤的机制奠定了基础。     

乙型肝炎病毒基因型与免疫复合物型治疗性乙肝疫苗应答相关性的研究

目的 研究对免疫复合物型治疗性乙肝疫苗不同应答乙肝患者的乙肝病毒基因型有无差别。方法 收集67例经60 ug HBsAg-HBIG (YIC) 治疗的慢性乙肝患者血清, 用S基因聚合酶链反应-限制性片段长度多态性分析(PCR-RFLP)法对其进行HBV基因分型,并结合患者对YIC治疗的不同应答进行分析。结果67例感染乙肝病毒（HBV）患者中,HBV B基因型22例,C基因型43例,未确定者2例。感染HBV B, C 两种基因型的患者对YIC免疫治疗的病毒学与HBeAg的血清转换应答差异无统计学意义. 结论HBV B或C基因型不影响慢性乙肝患者对YIC的治疗应答。     

太原地区乙肝患者HBV基因分型与细胞免疫功能研究

了解太原地区乙肝病毒基因型分布情况,研究不同基因型乙肝病毒致病性与细胞免疫功能关系。选择慢性乙肝、乙肝肝硬化及乙肝病毒相关肝癌等乙肝病毒感染患者,采用PCR技术检测患者血清HBV-DNA和HBV基因型,用流式细胞仪直接免疫荧光法(FCM)检测患者外周血T淋巴细胞亚群百分率,分析不同病毒基因型与乙肝病程关系以及不同基因型病毒感染患者细胞免疫功能状态。检测136例乙肝病毒感染患者,其中B基因型感染38例,占总数27.9%;C基因型感染93例,占总数70.6%;B/C混合型感染3例,占总数2.2%;D基因型感染2例,占总数1.5%。B型与C型乙肝病毒感染患者的HBsAg水平无区别,B型患者血清HBeAg(+)%高于C型乙肝病毒感染者,慢性无症状乙肝携带者、慢性乙肝、乙肝肝硬化和乙肝病毒相关的原发性肝细胞癌各组中乙肝病毒基因型的分布无差异,但乙肝肝硬化患者与慢性无症状乙肝携带者、慢性乙肝患者的基因型有差异(P<0.01),C基因型感染者HBV-DNA水平、HBeAg阳性率、CD4+细胞和CD4+/CD8+T淋巴细胞比值低于B基因型感染者。太原地区临床乙肝病毒感染患者以C基因型为主,C基因型感染者比B基因型的肝脏功能损害严重,可能与细胞免疫功能降低HBV-DNA水平和HBeAg阳性率高有关。     

应用酶联免疫吸附试验检测不同类型乙型肝炎中激活补体类HBsAg循环免疫复合物

本文以抗人C_(?)的羊IgG为包被抗体,以HRP-HBs抗体为指示抗体,建立了可检测激活补体类HBsAg循环免疫复合物(HBsAg/C3-CIC)的C_3捕捉法酶联免疫吸附试验。检测了236例六种类型临床诊断为乙型肝炎的病人血清标本,其阳性率分别为:无症状携带者(ASC)12.9％(4/31),急性肝炎(AH)36.7％(22/60),慢性迁延性肝炎(CPH)33.3％(7/21),慢性活动性肝炎(CAH)59.6％(34/57),重型肝炎(SH)77.8％(14/18),肝炎后肝硬化(PLC)67.3％(33/49),阳性率与肝损严重程度明显相关(P<0.01)。认为HBs-Ag/C3-CIC可能在乙型肝炎病毒引起的慢性活动性肝炎、重型肝炎和肝炎后肝硬化的发病过程中起重要作用,并可作为乙型肝炎的诊断、临床分型和预后判断的指标之一。     

乙型肝炎IgM和IgG—补体双特异性循环免疫复合物的意义

对不同临床类型的乙型肝炎患者,采用捕捉法ＥＬＩＳＡ,以ＩｇＭ和ＩｇＧ类抗体排除抗原性异物的免疫反应进行比较研究。结果发现,两种反应能力在慢性ＨＢＣ感染中基本相同,表现出明显的病型差异,而在急性ＨＢＶ感染中则不同,前者反应强度显著主于后者;二者阳性率在慢性ＨＢＶ感染的临床类型中虽均随其肝损害加重而显著上升,但ＩｇＧ／Ｃ３双特异性循环免疫复合物与ＡＬＴ有关,而ＩｇＭ／Ｃ３－ＴＣＩＣ与ＡＬＴ无关;二者阳     

Hepatitis B Surface Antigen Concentrations in Patients with HIV/HBV Co-Infection

HBsAg clearance is associated with clinical cure of chronic hepatitis B virus (HBV) infection. Quantification of HBsAg may help to predict HBsAg clearance during the natural course of HBV infection and during antiviral therapy. Most studies investigating quantitative HBsAg were performed in HBV mono-infected patients. However, the immune status is considered to be important for HBsAg decline and subsequent HBsAg loss. HIV co-infection unfavorably influences the course of chronic hepatitis B. In this cross-sectional study we investigated quantitative HBsAg in 173 HBV/HIV co-infected patients from 6 centers and evaluated the importance of immunodeficiency and antiretroviral therapy. We also compared 46 untreated HIV/HBV infected patients with 46 well-matched HBV mono-infected patients. HBsAg levels correlated with CD4 T-cell count and were higher in patients with more advanced HIV CDC stage. Patients on combination antiretroviral therapy (cART) including nucleos(t)ide analogues active against HBV demonstrated significant lower HBsAg levels compared to untreated patients. Importantly, HBsAg levels were significantly lower in patients who had a stronger increase between nadir CD4 and current CD4 T-cell count during cART. Untreated HIV/HBV patients demonstrated higher HBsAg levels than HBV mono-infected patients despite similar HBV DNA levels. In conclusion, HBsAg decline is dependent on an effective immune status. Restoration of CD4 T-cells during treatment with cART including nucleos(t)ide analogues seems to be important for HBsAg decrease and subsequent HBsAg loss.     

Cytokine expression during chronic versus occult hepatitis B virus infection in HIV co-infected individuals

Chronic hepatitis B virus infection is characterized by persistent detectable levels of hepatitis B surface antigen (HBsAg) and HBV DNA in the serum. In contrast, HBsAg is not detectable during occult HBV infection, despite the presence of HBV DNA. An altered host immune response could play a role in the development of occult HBV infection; however, potential differences in immune responses among chronic and occult HBV-infected patients have not been evaluated in vivo. In the current study, we evaluated serum levels of regulatory, apoptotic, and fibrotic/anti-fibrotic cytokines/markers as indicators of immune responses in 25 chronic and 12 occult HBV-infected patients. More than half of the patients in both chronic and occult HBV infection groups had IL-2, IL-4, IL-13, and IFN-γ levels below detectable limits. In contrast, most patients had detectable levels of IL-8, IL-10, IP-10, sFas, sFasL, and TGF-β1. Of these, only sFas was significantly different between the two groups, with lower levels observed during occult compared to chronic HBV infection (p = 0.01). As a surrogate marker of apoptotic inhibition, decreased sFas during occult HBV infection suggests that apoptosis occurs at different rates in occult compared to chronic HBV infection and therefore, may contribute to persistence of occult HBV infection.     

Vaccine- and hepatitis B immune globulin-induced escape mutations of hepatitis B virus surface antigen

Hepatitis B virus surface antigen (HBsAg) vaccination has been shown to be effective in preventing hepatitis B virus (HBV) infection. The protection is based on the induction of anti-HBs antibodies against a major cluster of antigenic epitopes of HBsAg, defined as the 'a' determinant region of small HBsAg. Prophylaxis of recurrent HBV infection in patients who have undergone liver transplantation for hepatitis B-related end-stage liver disease is achieved by the administration of hepatitis B immune globulins (HBIg) derived from HBsAg-vaccinated subjects. The anti-HBs-mediated immune pressure on HBV, however, seems to go along with the emergence and/or selection of immune escape HBV mutants that enable viral persistence in spite of adequate antibody titers. These HBsAg escape mutants harbor single or double point mutations that may significantly alter the immunological characteristics of HBsAg. Most escape mutations that influence HBsAg recognition by anti-HBs antibodies are located in the second 'a' determinant loop. Notably, HBsAg with an arginine replacement for glycine at amino acid 145 is considered the quintessential immune escape mutant because it has been isolated consistently in clinical samples of HBIg-treated individuals and vaccinated infants of chronically infected mothers. Direct binding studies with monoclonal antibodies demonstrated a more dramatic impact of this mutation on anti-HBs antibody recognition, compared with other point mutations in this antigenic domain. The clinical and epidemiological significance of these emerging HBsAg mutants will be a matter of research for years to come, especially as data available so far document that these mutants are viable and infectious strains. Strategies for vaccination programs and posttransplantation prophylaxis of recurrent hepatitis need to be developed that may prevent immune escape mutant HBV from spreading and to prevent these strains from becoming dominant during the next decennia.     

Development of a nasal vaccine for chronic hepatitis B infection that uses the ability of hepatitis B core antigen to stimulate a strong Th1 response against hepatitis B surface antigen

There are estimated to be 350 million chronic carriers of hepatitis B infection worldwide. Patients with chronic hepatitis B are at risk of liver cirrhosis with associated mortality because of hepatocellular carcinoma and other complications. An important goal, therefore, is the development of an effective therapeutic vaccine against chronic hepatitis B virus (HBV). A major barrier to the development of such a vaccine is the impaired immune response to HBV antigens observed in the T cells of affected patients. One strategy to overcome these barriers is to activate mucosal T cells through the use of nasal vaccination because this may overcome the systemic immune downregulation that results from HBV infection. In addition, it may be beneficial to present additional HBV epitopes beyond those contained in the traditional hepatitis B surface antigen (HbsAg) vaccine, for example, by using the hepatitis B core antigen (HBcAg). This is advantageous because HBcAg has a unique ability to act as a potent Th1 adjuvant to HbsAg, while also serving as an immunogenic target. In this study we describe the effect of coadministration of HBsAg and HBcAg as part of a strategy to develop a more potent and effective HBV therapeutic vaccine.     

Inhibition of the HCV Core Protein on the Immune Response to HBV Surface Antigen and on HBV Gene Expression and Replication In Vivo

The hepatitis C virus (HCV) core protein is a multifunctional protein that can interfere with the induction of an immune response. It has been reported that the HCV core protein inhibits HBV replication in vitro. In this study, we test the effect of the HCV core gene on the priming of the immune response to hepatitis B surface antigen (HBsAg) and on the replication of HBV in vivo. Our results showed that the full-length HCV core gene inhibits the induction of an immune response to the heterogeneous antigen, HBsAg, at the site of inoculation when HCV core (pC191) and HBsAg (pHBsAg) expression plasmids are co-administered as DNA vaccines into BALB/c mice. The observed interference effect of the HCV core occurs in the priming stage and is limited to the DNA form of the HBsAg antigen, but not to the protein form. The HCV core reduces the protective effect of the HBsAg when the HBsAg and the HCV core are co-administered as vaccines in an HBV hydrodynamic mouse model because the HCV core induces immune tolerance to the heterogeneous HBsAg DNA antigen. These results suggest that HCV core may play an important role in viral persistence by the attenuation of host immune responses to different antigens. We further tested whether the HCV core interfered with the priming of the immune response in hepatocytes via the hydrodynamic co-injection of an HBV replication-competent plasmid and an HCV core plasmid. The HCV core inhibited HBV replication and antigen expression in both BALB/c (H-2d) and C57BL/6 (H-2b) mice, the mouse models of acute and chronic hepatitis B virus infections. Thus, the HCV core inhibits the induction of a specific immune response to an HBsAg DNA vaccine. However, HCV C also interferes with HBV gene expression and replication in vivo, as observed in patients with coinfection.