Expression of HBsAg and HBcAg in liver tissue: correlation with disease activity.

The patterns of Hepatitis B surface antigen (HBsAg) and Hepatitis B core antigen (HBcAg) expression were studied in liver biopsies taken from 41 patients with chronic HBV disease. Immunohistochemical methods were used on deparaffinized sections for the identification of HBsAg and HBcAg in liver tissue. Twenty-one of the 41 cases (51.2%) were classified as inactive liver disease and 20 (48.8%) as active liver disease. In liver biopsies with inactive disease, HBsAg demonstrated varying types of cytoplasmic expression in a rather high number of hepatocytes distributed mainly in clusters, while HBcAg was rarely expressed in liver nuclei. On the other hand, in liver biopsies with active disease HBsAg was characterized by a diffuse cytoplasmic expression in a few discrete hepatocytes, while HBcAg was expressed in the nuclei of the hepatocytes in 70% of the cases and in half of the positive cases it was also detected in the cytoplasm. In conclusion, HBsAg expression in a few scattered hepatocytes correlates with active liver disease and positive HBcAg, while varying HBsAg cytoplasmic expression in a rather high number of clustered hepatocytes is related to chronic inactive liver disease and negative expression of HBcAg.     

Immunocytochemical investigation of hepatitis B virus-associated antigens in cases of liver cirrhosis and HBsAg antigenemia and their relationship to development of hepatocellular carcinoma

Summary Using light and ultrastructural immunoperoxidase techniques, we examined the distribution of hepatitis B virus (HBV)-associated antigens and the subcellular localization of hepatitis B surface antigen (HBsAg) in liver biopsies of HBsAg—positive patients with cirrhosis. The localization patterns of HBsAg in hepatocytes were membranous, cytoplasmic, festoon and inclusion body types. Cytoplasmic and festoon types were seen more often than the membranous type in pseudolobules, and hepatitis B core antigen (HBcAg)—positive cells with cytoplasmic type were distributed in the periphery of pseudolobules with active inflammation. Immunoelectron microscopy in the cytoplasmic or festoon type of HBsAg showed immunoreaction in the cisternae and on virus-like particles in the cisternae in patients with hepatitis B e antigen (HBeAg) antigenemia. Simultaneous staining of HBsAg and HBcAg revealed that hepatocytes with cytoplasmic or festoon type of HBsAg contained HBcAg—immunoreactivity. The inclusion body type of HBsAg was characteristic of liver cirrhosis with hepatocellular carcinoma (HCC); the subcellular localization of HBsAg was seen in clusters of the endoplasmic reticulum around the nucleus, and HBsAg—immunoreactivity was observed on many virus-like particles in most of the cisternae in those with HBeAg antigenemia. These findings suggest that the synthesis of HBsAg is active in patients with liver cirrhosis and that the formation of HBV is also active in those with HBeAg antigenemia and that HBV may be retained more in cirrhotic livers with hepatocellular carcinoma after proliferation than in those without it.     

乙肝肾患儿血清、肾脏和肝脏组织内乙肝病毒感染标志物的比较

目的:比较分析乙型肝炎病毒相关性肾炎(HBV-GN)患儿血清、肾脏和肝脏组织内HBV感染标志物的表达情况。方法:45例血清HBV感染标志物阳性的HBV-GN患儿经肾脏组织活检确诊,其中13例同时进行肝脏组织活检,且行HBV感染标志物免疫组织化学检查。结果:45例HBV-GN肾脏病理改变为:膜性肾病(MN)25例(55.6%)、系膜增生性肾炎(MsPGN)11例(24.4%)、膜增生性肾炎(MPGN)5例(11.1%)、毛细血管内皮增生性肾炎(EPGN)4例(8.9%),免疫荧光检查显示肾脏组织内以IgG(40例,88.9%)和C3(34例,75.6%)沉积为主。血清HBV感染标志物HBeAg( )组25例(55.6%),HBeAg(-)组20例(44.4%);肾脏组织中HBcAg的阳性率为80.0%(36/45),其中,血清HBeAg(-)组肾脏组织HBcAg阳性率(100.0%)明显高于血清HBeAg( )组(64.0%),(P=0.002)。肝肾同检结果显示HBV感染标志物(HBsAg和HBcAg)在肝脏组织表达的阳性率分别为84.6%和53.8%,在肾脏组织表达的阳性率分别为84.6%和76.9%,且肝、肾组织中HBV感染标志物表达不同步。结论:HBV-GN患儿血清、肾脏和肝脏组织内HBV感染标志物表达呈明显的不一致性。     

Rearrangement of the surface antigen gene of hepatitis B virus integrated in the human hepatoma cell lines.

The rearrangement of integrated HBV DNA sequences in three different hepatoma cell lines, huH-1, huH-2, KG-55-T from Japanese patients, were studied by blot hybridization using whole HBV genome or a HBsAg or HBcAg DNA as a probe. The characteristic existence of multiple integration sites of HBV DNA sequences in each HindIII-restricted hepatoma cell DNA was revealed by the HBV genome probe. Detection of the isolated HBsAg gene in the HindIII fragment indicates that the integration of HBV DNA was not always related to the maintenance of the whole viral genome, and that movement of the HBsAg gene to another location occurred by rearrangement. On the other hand, the presence of the HBV DNA sequence without the intact HBcAg gene was shown in some of the HindIII fragments, when the HBcAg gene, probe was used, but a HindIII fragment, containing only the HBcAg gene, was not detected so far. The absence of the intact HBcAg gene suggests that the viral genome may lose a part of the HBcAg gene in the process of integration. This is consistent with recent findings of Ogston et al. (1982) that in Woodchuck hepatocellular carcinoma viral sequences are extensively rearranged.     

Hepatitis B virus core antigen has two nuclear localization sequences in the arginine-rich carboxyl terminus.

Expression of the hepatitis B virus core antigen (HBcAg) in mouse NIH 3T3 fibroblasts has been shown previously (A. McLachlan et al., J. Virol. 61:683-692, 1987) to result in the nuclear localization of this polypeptide. Since the carboxyl terminus of HBcAg contains four clusters of arginine residues which resemble nuclear localization sequences identified in other nuclear proteins, a series of carboxyl-terminus-truncated HBcAg polypeptides were expressed in mouse fibroblasts to examine the role of these sequences in the cellular localization of HBcAg. By immunofluorescence and cell fractionation analysis, it was demonstrated that regions of the HBcAg polypeptide including the most carboxyl-terminal (cluster 1) and amino-terminal (cluster 4) clusters of arginine residues represent distinct and independent nuclear localization sequences for this polypeptide. Substitution of a threonine residue for the second arginine residue in cluster 4 inactivates the nuclear localization signal in this region of the HBcAg polypeptide, demonstrating the importance of this residue to this signal sequence. However, HBcAg fails to accumulate in the nucleus only when both nuclear localization signal sequences are simultaneously deleted or disrupted by mutation. The possible significance of the nuclear localization sequences identified in the HBcAg polypeptide is discussed in the context of the role of the nucleocapsid in the hepatitis B virus life cycle.     

热休克蛋白HSP70和gp96增强乙肝DNA疫苗的细胞和体液免疫应答

旨在以乙肝病毒 (HBV) 的主要结构蛋白-表面蛋白 (HBsAg) 和核心蛋白 (HBcAg) 作为抗原设计DNA疫苗,研究热休克蛋白HSP70和gp96作为新型免疫佐剂增强疫苗的细胞免疫和体液免疫水平。利用酶联免疫斑点实验、流式细胞内因子染色、3H-TdR实验、酶联免疫吸附实验技术分析,结果显示HSP70和gp96可使疫苗的细胞免疫水平提高1~6倍,提高体液免疫水平20％~60％。研究结果为设计以HSP70和gp96作为免疫佐剂的新型乙肝治疗性疫苗提供了依据。     

Methods for decreasing interstitial immunoglobulin in tissue slices and cryostat sections

To determine whether lymphoid antigens and cellular morphology can be preserved after long-distance transport in buffer or cell culture medium, we stained cryostat sections prepared from human tonsil samples that had been kept at 4 degrees C or 20 degrees C for 24, 48 or 72 h. B-Cell antigens, T-cell antigens, and Ia antigens were well preserved after storage up to 72 h in buffer or medium at 4 degrees C. Interstitial immunoglobulin (Ig) was decreased following all incubation procedures. We then investigated methods to diminish interstitial Ig in cryostat sections, since it would be inconvenient to keep 2-3 mm tissue slices in buffer or medium prior to freezing and subsequent Ig staining. Cryostat sections were air dried or briefly fixed in acetone prior to washing in buffer or medium at 4 degrees C, 20 degrees C or 37 degrees C for 1, 2 or 24 h. Then sections were air dried or washed prior to acetone fixation and immunostaining. A method for washing cryostat sections was developed which diminished interstitial Ig without compromising the quality of immunostaining or cellular detail. These methods are especially useful for studying samples of lymphoid tissue in which the presence of large quantities of interstitial Ig obscures the detection of monotypic Ig staining patterns.     

Expression of hepatitis B virus surface and core antigens: influences of pre-S and precore sequences.

Amphotropic retroviral expression systems were used to synthesize hepatitis B virus surface antigen (HBsAg) and core antigen. The vectors permitted establishment of cell lines which expressed antigen from either the retroviral long terminal repeat or the mouse metallothionein-I promoter. HBsAgs were synthesized containing no pre-S sequences, pre-S(2) sequences alone, or pre-S(1) plus pre-S(2) sequences. Inclusion of pre-S(2) sequences did not affect the secretion or density of HBsAg particles but did reduce their mass by approximately 30%. Addition of pre-S(1) sequences almost completely abolished secretion of HBsAg and resulted in its localization in an aqueous-nonextractable pre- or early-Golgi cellular compartment. HBsAg was localized to the cytoplasm of the cell. This localization was unaffected by the presence of pre-S sequences in the antigen. Cell lines synthesizing hepatitis B antigens from core DNA fragments, containing or not containing precore sequences, secreted hepatitis B e antigen. However, the absence of precore DNA sequences resulted in additional synthesis of hepatitis core antigen, which was predominantly nuclear in localization.     

乙型肝炎、肝硬变和肝癌中HBxAg的表达及其在肝癌发生中的作用

对３７９例良、恶性肝组织进行的免疫组织化学研究显示,３３％的慢性迁延性肝炎（６／１８）、７６％的慢性活动性肝炎（２６／３４）、９２％的肝硬变（５７／６２）和９７％的肝细胞性肝癌（ＨＣＣ）（５８／６０）中有ＨＢｘＡｇ表达,阳性率高于ＨＢｓＡｇ或ＨＢｃＡｇ。癌周肝中的ＨＢｘＡｇ阳性率显著高于非癌周肝。与其它２种ＨＢＶ抗原不同,ＨＢｘＡｇ表达在细胞类型上有较明显的选择性,在肝小多角细胞（ＳＰＬＣ）、小细胞性不典型增生（ＳＣＤ）及ＨＣＣ中较强。与ＩＧＦⅡ、ｃ－ｅｒｂＢ－２、ｃ－ｍｙｃ和ＥＧＦ－Ｒ表达进行的对照研究表明ＨＢｘＡｇ与ＩＧＦⅡ和ｃ－ｅｒｂＢ－２这２种ＨＣＣ发生相关基因的表达关系密切。ＰＣＮＡ染色结果显示ＨＢｘＡｇ阳性组织的细胞增殖活性显著高于ＨＢｘＡｇ阴性组织。我们的结果还表明ＨＢｘＡｇ表达与肝细胞不典型增生的发生和进展有关、提出ＨＢＶＸ基因可能通过其表达产物（ＨＢｘＡｇ）首先激活ＩＧＦⅡ、ｃ－ｅｒｂＢ－２基因,继而引起显著的ＳＰＬＣ增生和ＳＣＤ而参与ＨＣＣ发生的．     

Hepatitis B virus surface and core antigens in the liver of primary hepatocellular carcinoma cases in Virginia

Zenker-fixed paraffin-embedded sections of biopsy liver tissue from 64 cases of primary hepatocellular carcinoma (PHC) were stained for hepatitis B surface antigen (HBsAg) and for hepatitis B core antigen (HBcAg) by histochemical and/or immunohistochemical techniques in a retrospective study. PHC arose in livers with postnecrotic cirrhosis in 30 (46.9%) cases. Controls included liver biopsy sections from 123 miscellaneous liver disorders and from 67 randomly selected autopsy specimens, none of which were known to be associated with hepatitis B virus (HBV) infection. HBsAg was detected in tumorous hepatocytes in only one of the 64 cases of PHC. HBsAg was identified in nontumorous hepatocytes of 8 (20%) of 40 specimens that contained adequate nontumorous liver tissue. All of these HBsAg positive cases of PHC were associated with cirrhosis. Thus HBsAg was detected in 8 (33.3%) of 24 cases of PHC with cirrhosis, but in none of the remaining 16 cases without cirrhosis. HBcAg was not detected in the hepatocytes of those HBsAg positive PHC cases tested. Our results suggest that HBV infection may successively lead to chronic hepatitis, cirrhosis and ultimately PHC.     

Detection of a new antibody system reacting with Dane particles in hepatitis B virus infection.

Antibodies in the serum reacting with antigens on the surface of radiolabelled Dane particles distinct from hepatitis B surface and core antigens (HBsAg and HBcAg) were detected, using a double antibody precipitation assay, in 12 out of 15 patients early in the course of acute type B hepatitis and at the time of disappearance of circulating Dane particles. No such antibody activity was found in 15 of the 16 patients with HBsAg-positive chronic active hepatitis, 13 of whom had complete Dane particles in the serum. In a group of 16 asymptomatic HBsAg carriers (without Dane particles in serum) antibody activity was shown in nine. This demonstration of antibodies precipitating Dane particles may be relevant to the clearance of circulating hepatitis B virions and the termination of infection in acute type B hepatitis. Their absence in all but one of the cases of chronic active hepatitis might explain why the virus infection persists in this group of patients.     

Hepatitis B Virus-Specific miRNAs and Argonaute2 Play a Role in the Viral Life Cycle

Disease-specific serum miRNA profiles may serve as biomarkers and might reveal potential new avenues for therapy. An HBV-specific serum miRNA profile associated with HBV surface antigen (HBsAg) particles has recently been reported, and AGO2 and miRNAs have been shown to be stably associated with HBsAg in serum. We identified HBV-associated serum miRNAs using the Toray 3D array system in 10 healthy controls and 10 patients with chronic hepatitis B virus (HBV) infection. 19 selected miRNAs were then measured by quantitative RT-PCR in 248 chronic HBV patients and 22 healthy controls. MiRNA expression in serum versus liver tissue was also compared using biopsy samples. To examine the role of AGO2 during the HBV life cycle, we analyzed intracellular co-localization of AGO2 and HBV core (HBcAg) and surface (HBsAg) antigens using immunocytochemistry and proximity ligation assays in stably transfected HepG2 cells. The effect of AGO2 ablation on viral replication was assessed using siRNA. Several miRNAs, including miR-122, miR-22, and miR-99a, were up-regulated at least 1.5 fold (P<2E-08) in serum of HBV-infected patients. AGO2 and HBcAg were found to physically interact and co-localize in the ER and other subcellular compartments. HBs was also found to co-localize with AGO2 and was detected in multiple subcellular compartments. Conversely, HBx localized non-specifically in the nucleus and cytoplasm, and no interaction between AGO2 and HBx was detected. SiRNA ablation of AGO2 suppressed production of HBV DNA and HBs antigen in the supernatant.

Conclusion

These results suggest that AGO2 and HBV-specific miRNAs might play a role in the HBV life cycle.     

两种前S蛋白与HBV复制关系的初步研究

乙型肝炎病毒(HBV)前S基因及其产物的发现有助于认识HBV复制规律。一些研究提示:前S_1蛋白是完整病毒颗粒表面的必要成分,其存在与HBV复制密切相关,前S_1检测能敏感和特异地反映HBV复制状态。另一些研究则认为:前S_2蛋白含有人多聚白蛋白的结合位点,并提出前S_2蛋白为HBV复制的新标志。为探讨HBV复制与两种前S蛋白之间的联系,本研究应用原位分子杂交分析一组慢性肝炎患者肝细胞内HBV DNA,同时检测肝细胞内HBsAg、HBcAg与两种前S蛋白,综合分析两种前S蛋白在HBV复制中的地位和作用。     

Functional characterization of cloned intrahepatic, hepatitis B virus nucleoprotein-specific helper T cell lines

We have previously reported the establishment and preliminary characterization of polyclonal hepatitis B virus (HBV) nucleoprotein (HBcAg)-specific CD4+ and CD8+ T cell lines derived from the hepatic lymphomononuclear cell infiltrate of several patients with chronic active hepatitis B. The isolated subsets from these lines were specifically activated by HBcAg and displayed antigen-specific help and suppression with respect to proliferation of the alternate subset. One of these lines was recently cloned by limiting dilution, and four HBcAg-specific CD3+ CD4+ CD8-DR+ T cell lines were produced that had a 95.3% likelihood of monoclonality. Antigenic specificity was confirmed by dose-dependent, HLA class II (DR)-restricted proliferation in response to recombinant and human serum-derived HBcAg and the lack of proliferation to HBV envelope antigens (HBsAg and pre-S(2)Ag). All cloned lines were interleukin 2 dependent, produced interferon-gamma in an antigen-specific manner, and provided antigen-specific help to autologous B cells with respect to anti-HBc production. We conclude that HBcAg-specific, HLA-class II restricted helper T cells capable of inducing antigen-specific functional responses by autologous B lymphocytes and T lymphocytes are present at the site of viral antigen synthesis and hepatocellular injury in HBV infection.     

NIRF在体内外可明显抑制乙型肝炎病毒抗原的表达

随着对NIRF（Np95/ICBP-90 like RING finger protein）研究的深入,其功能已涉及细胞癌变进程以及表观遗传学等领域. 近期研究显示,NIRF能与HBc (hepatitis B virus core protein )相互结合,但其对乙型肝炎病毒(HBV)抗原表达的影响尚不明确. 本文通过转染pAAV-HBV1.3质粒和高压水动力法尾静脉注射BALB/C小鼠,建立乙型肝炎病毒的细胞和动物模型,研究NIRF对乙型肝炎病毒抗原表达的影响. ELISA检测细胞上清和小鼠血清中HBsAg、HBeAg的分泌和表达情况,Western 印迹或免疫组化染色技术检测HBcAg. 结果显示,乙型肝炎病毒抗原分泌的细胞以及小动物模型建立成功,并且无论在体内外,NIRF都能对它们的表达起抑制作用,期待能为后续的HBV致病机理以及治疗药物的研究提供支持与帮助.     

A recommended procedure for ultrastructural immunohistochemistry on small human tissue samples

Various fixation and staining procedures for the demonstration of surface and cytoplasmic antigens have been described. An immunostaining procedure was sought that would allow the demonstration of these antigens, especially in small human tissue samples at the ultrastructural level. A modification and adaptation of the technique of Eldred, Zucker, Karten, and Yazula (J Histochem Cytochem 31:285, 1983) was applied on several varieties of human tissue, including liver, skin, and lymphoid tissue, using monoclonal and polyclonal antibodies in an indirect peroxidase procedure. In this way a reliable and generally applicable procedure was developed that satisfied the following demands: Use of a universal fixative that allows preservation of the antigenicity of various antigens; Adequate penetration of the tissue by the immunological reagents; Optimal preservation of subcellular structures; and Possibility to store the tissue samples for considerable periods of time.     

Antigen retrieval in formalin-fixed, paraffin-embedded tissues: an enhancement method for immunohistochemical staining based on microwave oven heating of tissue sections.

We describe a new approach for retrieval of antigens from formalin-fixed, paraffin-embedded tissues and their subsequent staining by immunohistochemical techniques. This method of antigen retrieval is based on microwave heating of tissue sections attached to microscope slides to temperatures up to 100 degrees C in the presence of metal solutions. Among 52 monoclonal and polyclonal antibodies tested by this method, 39 antibodies demonstrated a significant increase in immunostaining, nine antibodies showed no change, and four antibodies showed reduced immunostaining. In particular, excellent immunostaining results were obtained with a monoclonal antibody to vimentin as well as several different keratin antibodies on routine formalin-fixed tissue sections after pre-treatment of the slides with this method. These results showed that after antigen retrieval: (a) enzyme predigestion of tissues could be omitted; (b) incubation times of primary antibodies could be significantly reduced, or dilutions of primary antibodies could be increased; (c) adequate staining could be achieved in long-term formalin-fixed tissues that failed to stain by conventional methods; and (d) certain antibodies which were typically unreactive with formalin-fixed tissues gave excellent staining.