大肠杆菌合成的乙型肝炎病毒核心抗原(HBcAg)转化为e抗原(HBeAg)的探索

本文以带有HBcAg基因重组质粒的大肠杆菌转化株Ecoli MM206所合成的HBcAg进行HBcAg转化为HBeAg的探索研究。菌经超声破碎获得的菌裂解液对生理盐水透析两天后,酶联检测发现抗原性部分转化为HBeAg。将菌裂解液或HBcAg精制品用2-巯基乙醇处理,可使抗原性发生进一步转化。但是分子筛层析证明抗原蛋白分子大小没有明显变化。这种制品有可能作为诊断试剂用以检测抗-HBe,而且实验结果表明HBeAg是由HBeAg衍变来的。为要提高HBeAg的稳定性,以碘乙酰胺处理,使还原的抗原蛋白通过羧甲基化反应封闭游离的巯基。经上述处理的HBeAg通过分子筛层析可与大部分细菌杂蛋白分开,制品只有HBeAg活性而测不到HBeAg活性,因而提高了抗原蛋白的稳定性与纯度。     

一种新的无传染性的检测HBeAg抗HBe的单克隆酶联免疫吸附法(MonoLISA)的建立与应用

应用我室自1988年5月以来建立的抗乙型肝炎e抗原两个抗原决定簇的单克隆抗体,和在大肠杆菌中高效表达的乙型肝炎病毒e抗原,组装成检测HBeAg/抗HBe的酶联免疫试剂(简称Mo-noLISA)。测定了该试剂的特异性、敏感性和可重复性,并与用日本单克隆抗体和血清e抗原组装的类似的EIA试剂进行了比较。结果两种试剂检测92份乙肝病人血清e抗原和38份血清e抗体的总符合率,分别为97.8％和100％。用两种试剂同时滴定一份已知HBeAg阳往和一份抗-HBe阳性的血清,证明两者的敏感性无显著差异。重复性试验证实,该试剂的重复率为100％。由此证明,用抗-HBeMcAb和基因工程抗原组装的诊断试剂,特异性强,敏感性高,可重复性好,且无传染性。这不仅为诊断试剂原材料的更新提供了丰富的来源,而且将该类试剂提高到一个新水平。     

抗乙型肝炎病毒e抗原和核心抗原双特异性单克隆抗体的建立与应用

用基因工程技术在大肠杆菌中高效表达的乙型肝炎病毒核心抗原(内含高滴度的e抗原)免疫Balb/C小鼠,取免疫小鼠脾细胞与小鼠骨髓瘤细胞(Sp2/0)融合,获得两株分泌高滴度既抗-HBe又抗-HBc的双特异性杂交瘤细胞系。细胞培养上清液中抗体滴度为100～1000以上;免疫腹水中的抗体滴度为8万至10万以上,均属IgG2a亚类。细胞在实验室连续传代二年多,仍保持高效分泌抗体能力。此单克隆抗体与HBeAg或HBcAg的结合可被抗-HBc或抗-HBc阳性血清所抑制,竞争抑制率在85.9％～96.8％之间。用此单克隆抗体与HBe的β型单克隆抗体和抗HBc的α型单克隆抗体配对,可组装成检测HBeAg/抗-HBe和抗-HBc的诊断试剂,具有重要的应用价值。     

抗HBeAg单克隆抗体杂交瘤细胞株的建立及快速检测试剂盒的制备

乙型肝炎病毒(HBV)是乙型肝炎的病原体,在我国感染率很高。检测血清中的e抗原(HBeAg)和和抗-HBe,在临床诊断、预后、母婴垂直传播的观察方面均具有重要意义,极须研制质量稳定、特异和敏感的快速诊断试剂。由於HBeAg的分子量小,免疫原性差,且与血清球蛋白及白蛋白有非特异性结合,不易将其分离以制备抗体,故我们采用SDS和2-ME两种变性剂,将大肠杆菌高效表达的基因工程HBcAg转变成HBeAg,转变后HBeAg的ELISA滴度可达1600以上,而HBcAg则不能测出。用此抗原免疫     

乙型肝炎病毒前S1抗原与HBV血清标志物同时检测及临床意义

目的：了解前S1抗原与HBV血清标志物的关系。方法：采用ELSIA方法同时检测2101例乙型肝炎病毒感染者的前S1抗原和HBV血清标志物。结果：29例HBsAg( )、HBeAg( )标本中,有28例前S1抗原阳性,阳性率96．55％;784例HBsAg( )、HBeAg( )、抗HBc( )标本中,有679例前S1抗原阳性,阳性率86．6l％;276例HBsAg( )、抗HBc( )标本中,有197例前S1抗原阳性,阳性率71．38％;1012例HBsAg( )、抗Hbe( )、抗HBc( )标本中,有468例前S1抗原阳性,阳性率46．25％。结论：前S1抗原作为病毒复制的指标与HBeAg具有很好的一致性,又具有其独立的检测价值,可弥补HBV血清标志物检测的不足。     

不同疗程小剂量干扰素对慢性乙型肝炎病毒标志物的影响

本文应用小剂量干扰素,从1个月至6个月不同疗程治疗97例HBsAg阳性伴HBeAg阳佳60例慢性乙型肝炎病人,以HBsAg、HBeAg、抗-HBe、HBcAg、DNAP和HBV-DNA 6项作为抗病毒指标,经1个月疗程97例,6项指标均无明显改善,经2个月疗程77例,只有DNAP阳性率下降和HBeAg阳性下降明显,经3个月疗程60例,5项病毒指标(除HBV-DNA外)均有统计学意义的下降,经6个月疗程42例,5项病毒指标阳性率稳定下降,下降缓慢的HBV-DNA(从73.24％下降为23.1％)和HBsAg(从100％下降为50％)也明显下降。这些病毒指标中以DNAP和HBeAg最敏感,次为HBcAg,再为HBV-DNA,最不敏感是HBsAg。本结果表明小剂量干扰素有抑制乙肝病毒复制怍用,长疗程(3个月以上)优于短程。     

应用转化细胞分泌的乙型肝炎病毒e抗原检测人血清中的乙型肝炎病毒e抗体

应用乙型肝炎病毒核心抗原基因转化的小鼠L细胞分泌的乙型肝炎病毒e抗原,采用ELISA法与Abbott公司抗-HBe EIA诊断盒平行比较,检测了31份抗-HBe阳性和19份抗-HBe阴性的人血清,结果完全相符。经多次重复试验,本法的OD490nm值的误差不超过8％。OD490nm值与血清稀释度之间呈直线关系。细胞培养液不经纯化即可应用,一般做1:4稀释。细胞分泌的抗原无感染性,价格低廉,不会因结合人血清蛋白而产生非特异性反应。因此比一般诊断盒中所用的人血清HBeAg有很大的优越性。     

抗乙型肝炎病毒表面抗原单克隆抗体的研究Ⅱ．抗HBsAg单克隆抗体的实际应用

本文用抗HBs／a McAb腹水用亲和层析法有效地提纯了HBsAg,回收率较高,并进行了CIEP检测临床血清标本,沉淀线清晰,检测灵敏度高于抗HBsAg血清。将抗HBs／a和抗HBs／d二种McAb提纯后制备诊断血球,进行RPHA检测临床血清标本千余例,并经美国Abbott实验室RIA试剂盒验证,表明其阳性检出率与中和试验符合率较国内目前以PcAb制备的诊断血球为优,显示了良好的特异性、灵敏度和准确性。抗HBsAgMcAb可作为新一代的HBsAg检测试剂。     

ELISA法检测HBeAg假性结果原因分析

目的:探讨ELISA法检测HBeAg假性结果原因方法:用ELISA法检测乙肝血清标志物,对HBsAg阳性而HBeAg阴性的标本以及HBeAg阳性的标本用ELISA法和电化学发光法复查。结果:136例HBsAg阳性而HBeAg阴性的标本经稀释复查后检出10例HBeAg阳性标本。23例溶血标本引起HBeAg假阳性。结论:钩状效应和标本溶血是引起HBeAg假阴性和假阳性的重要原因。必要时应加以复查,以减少HBeAg的错检和漏检。     

HBcAg表达菌株的筛选、初步鉴定与DNA顺序分析

为提高HBcAg(乙型肝炎核心抗原)在大肠杆菌体内表达水平,将有HBcAg的基因片段用核酸外切酶从两端消化,插入载体质粒pUR222的EcoRI酶切位点,转化Ecoli BMH71—18,用菌落原位酶联免疫法由275个转化子筛选到7株阳性克隆,用ELISA比较了它们的表达水平,表达水平最高者为M2066菌株,P/N=2.0时菌体裂解液的稀泽度为1:33000’比表达最低者M2098高8,000倍,比第一代菌株M206高15,000倍,DNA顺序分析结果表明与mRNA起始密码上游的发卡结构去除有关。用SDS-PAGE和聚乙烯簿膜复印法检测菌体裂解液中HBcAg的分子量为21000,42000及63000,呈单体和聚合物形式存在,比由病人肝脏和血液中提取的HBcAg(19000)分子量大,为融合蛋白。经琼脂免疫双扩散与ELISA阻断试验未发现与β半乳糖苷酶有免疫学交叉反应。用ELIDA法,M2066-HBcAg与肝-HBcAg同时检测40份血清标本的抗-HBc,二者符合率95％。     

Age-specific prevalence of hepatitis B e antigen (HBeAg) and antibody to HBeAg (anti-HBe) among asymptomatic hepatitis B surface antigen (HBsAg) carriers in Okinawa and Kyushu, Japan

A total of 1,741 asymptomatic hepatitis B surface antigen (HBsAg) carriers in two areas (Okinawa and Kyushu) in Japan were surveyed for the presence of hepatitis B e antigen (HBeAg) and the corresponding antibody (anti-HBe) to determine the age-specific prevalence of these markers and the mean age of carriers with HBeAg. Prevalence of HBeAg was significantly higher in Kyushu (36.4% of 755 carriers) than in Okinawa (20.0% of 986 carriers) (P less than 0.001). The mean age of carriers with HBeAg was 25.5 years in Kyushu and 16.1 years in Okinawa, suggesting that HBeAg converted to anti-HBe earlier in Okinawa than in Kyushu. In contrast, the prevalence of anti-HBe was significantly higher in Okinawa (74.6% of 986) than in Kyushu (56.3% of 755) (P less than 0.001). The prevalence of HBeAg decreased with age up to 40-49 years of age and then increased in both areas. Prevalence of anti-HBe was inversely related to the prevalence of HBeAg in both areas. These data suggest that HBeAg and anti-HBe are chronological markers of chronic hepatitis B virus infection and that the duration of HBeAg persistence can be different in different area, even in the same country.     

乙型肝炎病毒e抗原的生物学功能及血清学转换的免疫学基础

目前在临床乙型肝炎的治疗中,乙型肝炎病毒e抗原(HBeAg)消失及其抗体的出现已成为重要的疗效指标.本文回顾了HBeAg的发现及其生物学和医学意义,对HBeAg与乙型肝炎病毒核心抗原(HBcAg)的免疫原性进行了比较,阐述了HBeAg血清学转换的免疫学基础,并对出现HBeAg血清学转换的意义作了分析.     

Demonstration of two distinct antigenic determinants on hepatitis B e antigen by monoclonal antibodies

Mice were immunized against hepatitis B e antigen (HBeAg) isolated from sera of asymptomatic carriers of hepatitis B virus. Their spleen cells were fused with mouse myeloma (NS-1) cells, and 5 clones of hybridoma cells secreting antibody against HBeAg (anti-HBe) were isolated. For the production of anti-HBe in large scale, cells were cultivated both in vitro and in the peritoneal cavity of ascitic mice. Although monoclonal antibodies produced by these clones showed a strong reactivity of anti-HBe in hemagglutination tests, individual monoclonal anti-HBe did not reveal any precipitin line in immunodiffusion. When 2 of the 5 monoclonal antibodies were mixed together, however, some combinations showed a precipitin line against HBeAg, whereas others did not. Utilizing solid-phase radioimmunoassay involving a number of combinations of monoclonal antibodies used for solid-phase and radiolabeling, the 5 antibodies were classified into 2 groups. Three of the anti-HBe antibodies were found to be directed to 1 determinant of HBeAg (determinant a); the remaining 2 to the other determinant (determinant b). Determinants a and b were detected on HBeAg in the serum, as well as on the polypeptide of 19,000 daltons (P19) derived from the nucleocapsid of hepatitis B virus. Monoclonal anti-HBe antibodies with different specificities may provide useful tools in delineating the antigenic structure of HBeAg and also in evaluating immune responses of the host directed to its subdeterminants.     

Enzyme immunoassay of HBeAg employing beta-D-galactosidase

An enzyme-linked immunosorbent assay (ELISA) system for hepatitis B e antigen (HBeAg) was developed employing beta-D-galactosidase conjugated with antibody to HBeAg (anti-HBe) and using m-maleimidobenzoyl-N-hydroxysuccinimide ester as the coupling reagent. The experimental conditions for quantitative assay of HBeAg were determined. The presence of rheumatoid factor in test sera did not affect the results. This assay system is more sensitive than the micro-Ouchterlony method and as sensitive as radioimmunoassay. The use of beta-D-galactosidase for ELISA in the field of virology is recommended.     

Identification of a major hepatitis B core antigen (HBcAg) determinant by using synthetic peptides and monoclonal antibodies

To map the location of hepatitis B core and e Ag (HBcAg and HBeAg) on the hepatitis B virus core particle, we produced and analyzed four synthetic peptides which correspond to the most hydrophilic regions of the core P22 protein. Each peptide was tested in an ELISA for the ability to inhibit the binding between rHBcAg or rHBeAg and either polyclonal or monoclonal anti-HBc or anti-HBe antibodies. The former comprised 20 antisera positive for anti-HBc (anti-HBs and anti-HBe negative) and five antisera positive for anti-HBe and anti-HBc; the latter included three anti-HBc mAb developed in independent laboratories: G6F5, C51B10, and F8, as well as two anti-HBe mAb, E2 and E6. These experiments revealed the presence of a major HBcAg epitope expressed on C3, a peptide which covers amino acids 107-118 and reacted with all polyclonal and monoclonal antibodies tested. Another peptide, C2, sequence 73-85, reacted with 26% of human antisera but none of the anti-HBc mAb. None of the peptides seemed to express HBeAg activity because they do not cause any significant inhibition of the HBeAg/anti-HBe reaction. These data indicate the expression of an immunodominant HBcAg determinant on a linear dodecapeptide and argue against a strict conformation dependency of this Ag.     

Sex- and age-specific prevalences of HBeAg and anti-HBe among HBsAg carriers with or without liver function abnormalities in Okinawa, Japan

We investigated sex- and age-specific prevalences of hepatitis B e antigen (HBeAg) and antibody to HBeAg (anti-HBe) in 1,163 carriers of hepatitis B surface antigen (HBsAg) in Okinawa, Japan, and followed them up for longer than one year in correlation with liver function abnormalities. Elevated serum transaminase levels were found in 160 (13.8%) of them. The prevalence of liver function abnormalities was significantly higher in male carriers (127/690, 18.4%) than in female carriers (33/473, 7.0%) at a P value of 0.001. In asymptomatic carriers, the prevalence of HBeAg was 13.2% and that of anti-HBe 80.0%, significantly different from 41.9% and 54.4%, respectively, in carriers with elevated transaminase levels (P less than 0.001). In asymptomatic carriers, the mean age of HBeAg-positive carriers was 16.7 years which was much lower than the 22.8 years in carriers with liver function abnormalities. The prevalence of elevated transaminase levels was significantly higher in carriers with HBeAg than in those with anti-HBe (33.8% vs. 9.7%, P less than 0.001). Based on these results, the prolonged positivity for serum HBeAg would qualify as a predictor for deteriorating liver function among HBsAg carriers.     

Detection of hepatitis B virus DNA in mononuclear blood cells.

The Southern transfer hybridisation technique was used to test mononuclear blood cells for hepatitis B virus DNA. Viral DNA sequences were detected in mononuclear cells of 10 out of 16 patients with hepatitis B virus infection and in none of 21 normal controls. Blood contamination was excluded by the absence of hepatitis B virus DNA in the corresponding serum samples in all cases. Free monomeric hepatitis B virus DNA was found in three patients positive for hepatitis Be antigen (HBeAg) and one positive for anti-HBe, and integrated hepatitis B virus DNA was present in four patients positive for anti-HBe. In two other patients the small size of the samples did not allow a distinction between free and integrated viral DNA. The state of the virus in the mononuclear cells seemed to correlate with the HBeAg or anti-HBe state, as has been noted in the liver. These results indicate that hepatitis B virus may infect mononuclear blood cells, thereby expanding the tissue specificity of this agent beyond the liver, as has been reported for pancreatic, kidney, and skin tissue. They also suggest that hepatitis B virus infection of mononuclear cells might be related to immunological abnormalities observed in carriers of the virus.