Detection of hepatitis B surface antigen (HBsAg) in peripheral blood mononuclear cells of patients with acute and chronic active hepatitis B

Seventy five patients with acute and chronic active hepatitis (CAH) were studied by indirect immunofluorescence with monoclonal antibodies for the presence of hepatitis B surface antigen (HBsAg) on peripheral blood mononuclear cells (PBMC). The viral surface antigen was detected in the PBMC of all the patients with hepatitis B virus (HBV)-induced CAH and in acute patients with more than 2 months of evolution. No HBsAg was detected in the samples obtained from 12 normal controls or from 14 non-A, non-B CAH patients. Analysis of PBMC subsets revealed that HBsAg was present in non-T cells; dual fluorescence studies showed HBsAg on surface Ig-positive lymphocytes. The binding of anti-HBs monoclonal antibodies was higher than that of a goat anti-HBs serum, and the highest reactivity was observed with an antibody against the pre-S(2)-region sequence. Both HBsAg and hepatitis B core antigen (HBcAg) were also detected in lysates of PBMC by dot blot analysis.     

Hepatitis B virus (HBV) antigen-pulsed monocyte-derived dendritic cells from HBV-associated hepatocellular carcinoma patients significantly enhance specific T cell responses in vitro

To investigate whether hepatitis B virus (HBV) antigen-pulsed monocyte-derived dendritic cells (MoDC) could mount a T cell response in hepatocellular carcinoma (HCC) patients associated with chronic HBV infection, peripheral blood mononuclear cells (PBMCs) from 36 HBV-associated HCC patients were induced into MoDC and pulsed with hepatitis B core antigen (HBcAg) and hepatitis B surface antigen (HBsAg), alone and in combination. Co-stimulatory molecules CD80, CD86 and CD40, as well as human leucocyte antigens D-related (HLA-DR) were found to express at the highest level on MoDC pulsed with HBcAg or HBsAg + HBcAg, at a median level on MoDC pulsed with HBcAg or HBsAg alone, and at the lowest level on non-antigen-pulsed MoDC. Interleukin (IL)-10 and IL-12 cytokines were released by antigen-pulsed MoDC at increased levels in the order: no-antigen < HBsAg < HBcAg < HBcAg + HBsAg. MoDC pulsed with HBcAg or HBsAg + HBcAg also had the strongest ability to stimulate autologous T cell proliferation and intracellular interferon (IFN)-gamma production. HBcAg- or HBsAg + HBcAg-pulsed MoDC could also induce HBV core peptide-specific CD8(+) T cell proliferation determined by tetramer staining. In addition, the antigen-pulsed MoDC were found to have a stronger capacity to produce IL-12 and induce T cell response in vitro for patients with higher alanine transaminase (ALT) levels than those with lower ALT levels, indicating that antigen pulse could substantially reverse the impaired function of MoDC in primary HCC patients with active chronic hepatitis B. In conclusion, HBV antigen-pulsed MoDC from HCC patients with chronic hepatitis B could induce HBV-specific T cell response in vitro.     

In vitro immune responses to hepatitis B surface antigen (pre-S2 and S) following remote infection by hepatitis B virus in humans

In this report we evaluate the human immune response to hepatitis B surface antigen (HBsAg) following remote infection with hepatitis B virus (HBV). HBsAg-reactive lymphocytes can be readily demonstrated in the peripheral blood of individuals with established immunity following infection with HBV.In vitro stimulation with small doses of plasma-derived HBsAg, yeast-derived HBsAg (S region) or pre-S2 peptide will induce specific IgG to HBsAg (anti-HBs) in the absence of a polyclonal increase in total IgG. The pre-S2 peptide will stimulate, in a T cell-dependent fashion, thein vitro production of anti-HBs with specificity for the S domain. This anti-HBs production is mediated by pre-S2-stimulated soluble T-cell factors. Peripheral blood mononuclear cells from individuals with established immunity proliferate to the yeast-derived HBsAg but not to the plasma-derived HBsAg or pre-S2 peptide. The chronic HBsAg carriers do not produce anti-HBs following stimulation with HBsAg regardless of the source or component of antigen used. Different study protocols failed to demonstrate HBsAg-specific responses in the peripheral blood mononuclear cells of chronic carriers.     

抗原活化慢性乙型肝炎患者外周血树突状细胞的对比研究

目的 探讨不同抗原在体外活化慢性乙型肝炎患者外周血树突状细胞(DC)及诱导特异性T细胞应答的能力.方法 用无血清培养基从慢性乙型肝炎患者外周血中分离培养DC,在DC成熟前,分别加入HBsAg多肽、HBcAg多肽刺激,用流式细胞仪检测DC表型,用液闪计数仪观察DC对T细胞的增殖作用,用ELISA法检测混合淋巴细胞反应(MLR)中IL-12的分泌水平.结果 经HBcAg多肽刺激DC的CD86表达率为(92.20±5.18)%,明显高于HBsAg多肽刺激组(76.19±3.90)%和未加抗原组(62.37±4.24)%,P＜0.01;经HBcAg多肽刺激组DC诱导同种异体静止T细胞增殖的能力每分钟液闪计数值cpm为34 326±3088,明显高于HBsAg多肽刺激组20 306±2897和单个核细胞组3454±409,P＜0.01;经HBcAg多肽刺激组DC MLR中IL-12(348±42.8)ng/L,分别高于HBsAg多肽刺激组(226±30.6)ng/L和未加抗原组(116±15.6)ng/L,P＜0.01.结论 使用HBcAg多肽刺激DC可比HBsAg多肽更有效地提呈病毒抗原,提高诱导特异性T细胞应答的能力.     

Lymphocyte blast transformation to HBsAg and HBcAg in patients with various clinical forms of hepatitis B

Sensitization of the peripheral blood lymphocytes to HBsAg and HBcAg in 51 patients with acute hepatitis B (HB) in the time course of infection, in 13 with chronic active hepatitis B (CAH) and 8 HBsAg carriers was studied by lymphocyte blastogenesis assay. In patients with mild or moderately severe forms of acute HB at the peak of the disease lymphocyte blastogenic response to HBcAg was observed; sensitization to HBsAg was lacking and could be detected only in the stage of convalescence when the specific response to HBcAg was already undetectable in most patients. No lymphocyte sensitization to HBsAg either at the peak of the disease or in convalescence was observed in patients with a lingering form of acute HB as well as in those with CAH and HBsAg carriers. At the peak of severe HB blastogenic response was demonstrated to both antigens under study but was more marked to HBcAg. Most patients with CAH showed lymphocyte blastogenic response to HBcAg. It is concluded that specific lymphocyte response to HBV antigens varies in relation to the severity and course of the infection.     

Differential effect of chronic hepatitis D virus infection on intrahepatic expression of hepatitis B viral antigen.

AIMS: To determine how chronic hepatitis D virus (HDV) infection affects intrahepatic hepatitis B virus (HBV) antigen expression. METHODS: Ninety eight liver biopsy specimens from 68 patients seropositive for total antibody to HDV were studied by immunohistochemistry, and the amount of HBV antigens was also quantified by radioimmunoassay in 12 patients and compared with 30 patients with chronic HBV infection. RESULTS: Forty nine of the 68 patients were positive for intrahepatic HDV antigen and only five were positive for HBV core antigen (HBcAg). HBV surface antigen (HBsAg) was present in 55 (80.9%) patients and was always cytoplasmic in distribution. Hepatic pre-S1 and pre-S2 expressions paralleled that of HBsAg, and were detected in 53 (77.9%) and 54 (79.4%) patients, respectively. There was no relation between the intrahepatic expression of HDV antigen and HBsAg/pre-S1/pre-S2. Follow up biopsy specimens in 25 patients showed either static or deteriorating histology while intrahepatic HDV antigen remained the same or fell. The patients with intrahepatic expression of HBcAg had either absent or noticeably decreased expression of HBcAg in their follow up biopsy specimens (median two years). In contrast, HBsAg/pre-S1/pre-S2 were the same or increased (p less than 0.001). Quantification of intrahepatic HBsAg in patients with chronic HDV infection (0.61 pg/hepatocyte, range: 0.05-1.08, n = 12) showed no difference with patients with chronic HBV infection alone (0.64 pg/hepatocyte, range: 0.02-1.02, n = 30, p = NS). CONCLUSION: These data indicate that chronic HDV infection suppresses intrahepatic expression of HBcAg but not HbsAg and pre-S antigens, suggesting a differential effect of chronic HDV infection on HBV gene expression.     

In vitro use of autologous dendritic cells improves detection of T cell responses to hepatitis B virus (HBV) antigens

T lymphocyte responses to hepatitis B virus (HBV) core antigen (HBcAg) are vigorous and easily detectable in vitro during recovery from acute hepatitis B but significantly weaker in patients with chronic HBV infection. In contrast, T cell responses to hepatitis B surface antigen (HBsAg) are almost undetectable during infection and even in a substantial fraction of subjects receiving vaccination with HBsAg. The aim of this study was to investigate whether the use of dendritic cells (DCs) in an in vitro assay could increase the detection of HBV‐specific T cells in these conditions. Autologous monocyte‐derived DCs, compared to direct HBsAg addition to the cultures, increased the stimulation of HBs‐ specific T cells. These were detected in 73% of healthy subjects who had recently received hepatitis B vaccine and in 43% of patients recovering from acute hepatitis B. Likewise, proliferation in response to DC‐presented HBcAg was detected in both CD4⁺ and CD8⁺ T cells from the majority of chronic hepatitis B patients. A longitudinal evaluation of HBc‐specific T cell responses during and after a 1‐year treatment with pegylated interferon (IFN)‐α showed that HBc‐specific CD4⁺ T cell responses had no correlation with sustained virus suppression whereas CD8⁺ T cell responses were more frequently detected in patients able to control HBV replication after therapy interruption. The use of autologous DCs as antigen‐presenting cells appears applicable to clinically relevant in vitro evaluation of T cell responses, particularly in those conditions characterized by low frequency of circulating antigen‐specific cells and suboptimal in vivo activation. J. Med. Virol. 81:332–339, 2009. © 2008 Wiley‐Liss, Inc.     

Hepatitis B Virus Antigens in Peripheral Blood Mononuclear Cells during the Course of Viral Infection

We studied the expression of surface (HBsAg) and core (HBcAg) proteins of hepatitis B virus (HBV) on the surface of peripheral blood mononuclear cells (PBMC) from HBV-infected patients. A total of 122 patients with different liver viral diseases was analyzed by indirect immunofluorescence with monoclonal antibodies. The 35 patients with HBV chronic active hepatitis (CAH) and 38 of 60 patients with acute hepatitis B (63%) expressed HBsAg on the PBMC. No expression was detected on the cells from both normal and HBV-unrelated viral hepatitis control groups. Serial follow-up of patients with acute hepatitis B showed that HBsAg expression by PBMC tended to be undetectable 4 months after the onset of the disease and at the same time the clinical improvement was evident. Cell cultures of EBV-transformed B lymphocytes were established from PBMC of HBV-infected patients; immunoelectron microscopy demonstrated the HBsAg on the cellular membrane. One-third of HBV-infected patients who were studied showed the expression of HBcAg by PBMC. HBcAg was detected in patients with acute hepatitis B at the early stage of infection. The cells of these patients also expressed HBsAg in PBMC. In CAH patients, a positive association was observed between the expression of HBcAg and the presence of serum HBeAg.     

慢性乙肝患者抗病毒治疗前后特异性T细胞免疫观察

目的 了解抗病毒治疗前后慢性乙型肝炎患者特异性T淋巴细胞对HBV抗原蛋白免疫应答的变化及其特征.方法 收集17例慢性乙型肝炎患者抗病毒治疗前及治疗后1个月、3个月的外周血单个核细胞,以HBV特异性抗原蛋白HBsAg、HBcAg和HBeAg为刺激物,酶联免疫斑点法检测其分泌IFN-γ产生斑点的情况.同时对血清HBV DNA和HBsAg、HBeAg等病毒学指标及谷丙转氨酶(ALT)等生化学指标进行榆测并分析其相关性.结果 治疗前,所有患者ALT、总胆红素(TBiL)均高于正常上限,17例患者HBV DNA均大于104拷贝/ml;治疗1个月后,ALT复常率为35.3%,9例患者HBV DNA降为检测下限以下;治疗3个月后,ALT复常率为58.8%,有11例患者HBV DNA降为检测下限以下.抗病毒治疗前、治疗1个月、治疗3个月患者针对HBV特异性蛋白总的T细胞反应阳性率分别为64.7%、76.5%和82.4%,其差别无统计学意义.不论治疗前后,患者对HBeAg的特异性T细胞反应频率和平均反应强度最高;治疗后,对3种蛋白的特异性T细胞反应频率和平均反应强度各有不同程度的增加,其中以对HBcAg蛋白的平均反应强度的增强最明显,治疗前和治疗3个月,治疗1个月和治疗3个月之间的差别都有统计学意义.患者对HBcAg蛋白的特异性T细胞反应平均反应强度与病毒载量有明娃负相关,与血清ALT无明显相关性.结论 本研究结果提示抗病毒治疗后,患者对HBV的特异性T细胞免疫应答有所增强,这种改变可能与HBV DNA的下降有关,检测HBV特异性T细胞反应对丁解患者的免疫状态有重要的意义.

Abstract：

Objective To explore the responses of antigen-specific T cells stimulated by hepatitis B virus(HBV)-specific proteins in chronic hepatitis B patients accepting antiviral therapy. Methods Seventeen patients with chronic hepatitis B (CHB) accepting antiviral therapy were included in this study. The peripheral blood monocular cell ( PBMC) were separated from the whole blood collected at the three different time of before and one and three months after accepting antiviral therapy. ELISPOT assay was used to detect the frequency and strength of secreting IFN-γ cells of PBMC stimulated by HBsAg, HBcAg and HBeAg. HBV virus loading, HBsAg, HBeAg, ALT and AST in serum were detected at the same time. Results After three months therapy, ALT, TBiL were improved in all patients, and HBV DNA level were dropped and undetectable in 11 cases. The rates of T cell response in patients to HBV specific proteins were 64. 7% , 76. 5% and 82. 4% at the time of before and one and three months after accepting antiviral therapy, respectively. The frequency of responses of antigen-specific T cells stimulated by HBcAg was higher than that stimulated by HBsAg or HBeAg, and the frequency was enhanced after antiviral therapy. The average response magnitude was expressed as spot forming cells (SFC) per million input cells. SFC of T cell responses to HBcAg was also higher than to HBsAg or HBeAg. There was no significant difference in SFC of T cell responses to HBsAg or HBeAg at the time of before and after antiviral therapy, but there were significant difference in SFC of T cell responses to HBcAg at the time of before and after antiviral therapy. SFC of T cell responses to HBcAg was negatively associated with HBV DNA, and no associated with level of ALT in serum. Conclusion The responses of antigen-specific T cells were improved in CHB patients accepting antiviral therapy which associated with the decrease of HBV DNA. It suggested to investigate HBV specific T cell responses was important.     

HBsAg-induced antigen-specific T and B lymphocyte responses in chronic hepatitis B virus carriers and immune individuals.

This report describes a study of in vitro proliferative and antibody responses to the hepatitis B virus surface antigen (HBsAg) of lymphocytes from chronic HBsAg carriers, subjects with naturally acquired immunity, and responders to the hepatitis B vaccine. Peripheral blood T and B lymphocytes were cultured with a wide range of concentrations of HBsAg (0.025-250 ng/ml). We were unable to detect HBsAg-specific proliferation or antibody synthesis in any of the subject groups studied, despite the use of a range of antigen concentrations, cell ratios and culture periods. The addition of recombinant interleukin 2 (rIL-2) or T cell growth factor at either initiation or day 3 of culture enhanced proliferative responses, but in an antigen-independent manner. In contrast to the proliferation observed following the addition of IL-2, the absence of responses to specific antigen suggest there may be low numbers of HBsAg-specific precursors in the peripheral blood.     

Pokeweed mitogen-induced immunoglobulin-secreting cells in Hepatitis B surface antigen-positive -negative chronic active hepatitis: Evaluation by a protein A plaque assay

The response to pokeweed mitogen (PWM) of peripheral blood mononuclear cells was evaluated in 7 patients with Hepatitis B surface antigen (HBsAg)-positive and 16 patients with HBsAg-negative chronic active hepatitis (CAH). Immunoglobulin-secreting cells were assessed by a reverse hemolytic plaque assay with protein A-coated sheep red blood cells. HBsAg-negative patients with CAH, but not HBsAg-positive patients with CAH, showed a markedly impaired response to PWM compared to healthy controls. Coculture experiments of mononuclear cells from most unresponsive patients with HBsAg-negative CAH and mononuclear cells from healthy controls demonstrated a higher than expected response to PWM, suggesting that a quantitative or functional defect of a cell population with a “helper” effect for the in vitro response to PWM may be present in some patients. The hyporesponsiveness to PWM in HBsAg-negative patients with CAH, but not in patients with HBsAg-positive CAH, represents and additional difference in immunologic parameters between these two types of chronic liver disease.     

Definition of hepatitis B virus (HBV)-specific target antigens recognized by cytotoxic T cells in acute HBV infection.

We have investigated the specificity of cell-mediated cytotoxicity for autologous liver cells in 10 patients with acute hepatitis B in relation to the expression of hepatitis B virus (HBV) antigens and IgG on the surface of hepatocytes. Hepatitis B core antigen (HBcAg) was expressed on hepatocytes from six patients and hepatitis B surface antigen (HBcAG) from four, though always in association with HBcAg. Peripheral blood mononuclear cells (PBMC) were significantly cytotoxic in eight of the patients, and fractionation experiments revealed that the cytotoxic effect was equally mediated by T and non-T cells. Monoclonal antibody blocking experiments showed that HBcAg was the major target antigen recognized by T cells, although some inhibition of cytotoxicity was observed after pretreatment of target cells with monoclonal anti-HBs in patients with liver cell surface HBsAg. In contrast, non-T cells were not consistently inhibited by either monoclonal anti-HBc or anti-HBs. These findings further suggest that the HBV nucleoprotein serves as a target for recognition by cytotoxic T cells.     

Virus-specific lymphokine production differs quantitatively but not qualitatively in acute and chronic hepatitis B infection.

Cytokines that are secreted as a response to viral antigen not only have direct antiviral properties but also crucially influence immune reactions determining the outcome of infection. As an advantageous alternative to the study of cytokines present in the supernatants of antigen-specific T cell clones and lines, we have used ELISPOT assays to determine the number of interferon-gamma (IFN-gamma)- and IL4-producing cells generated by peripheral blood mononuclear cells from patients with acute hepatitis B (AHB) and chronic hepatitis B (CHB) infection in response to HBcAg in a short-term culture (48 h). In response to HBcAg IFN-gamma was predominantly produced. In contrast to the results obtained in acute hepatitis B, the typical lymphokine pattern in CHB was characterized by a weak or absent antigen-specific IFN-gamma production. A predominance of IL-4-producing cells was not observed in either AHB or CHB. A significant number of IFN-gamma-producing cells was usually detectable during phases of viral elimination and the quality of the lymphokine response seemed to be epitope independent. Comparison of the results obtained in proliferation assays and ELISPOT assays clearly shows that lymphokine production upon stimulation with viral protein is totally independent of T cell proliferation and more sensitively reflects antiviral reactivity.     

Immunohistological study of intrahepatic expression of hepatitis B core and E antigens in chronic type B hepatitis.

AIMS: To study the intrahepatic expression of hepatitis B virus (HBV) nucleocapsid antigen; and to determine the differential distribution of hepatitis B core and E antigens in chronic hepatitis B. METHODS: Hepatocyte expression of HBV nucleocapsid antigen was studied using rabbit anti-HBc, directed against both HBcAg and HBeAg; differential distribution of HBcAg and HBeAg was studied using murine monoclonal anti-HBc and anti-HBe in 120 patients with chronic hepatitis B. RESULTS: HBV nucleocapsid antigen was detected in 14 of 16 (87.5%) HBeAg seropositive patients with chronic persistent hepatitis (CPH), and in 54 of 64 (84.4%) HBeAg seropositive patients with chronic active hepatitis (CAH). Nuclear expression of nucleocapsid antigen was more prevalent in patients with CPH than in those with CAH; this was reversed in terms of exclusive cytoplasmic expression of nucleocapsid antigen (p < 0.05). Of 45 patients with nucleocapsid antigen in the nucleus, samples from 44 (97.8%) and 17 (37.8%) stained positively with monoclonal anti-HBc and anti-HBe, respectively. Of 65 patients with cytoplasmic nucleocapsid antigen, samples from 61 (93.8%) and 57 (87.7%) stained positively with monoclonal anti-HBc and anti-HBe, respectively. CONCLUSIONS: HBV nucleocapsid antigen is more prevalent in HBeAg positive patients with CPH than in those with CAH. Cellular expression of HBcAg and HBeAg in the cytoplasm is more or less the same; in the nucleus HBcAg exceeds HBeAg expression.     

HBcAg‐Specific IL‐21‐Producing CD4+ T Cells are Associated with Relative Viral Control in Patients with Chronic Hepatitis B

Function exhaustion of specific cytotoxic CD8+ T cell in chronic virus infection partly results from the low levels of CD4 help, but the mechanisms by which CD4 help T cell required to control hepatitis B virus infection are not well understood. In this study, we investigated the role of interleukin‐21‐producing CD4+ T cell response in viral control of hepatitis B virus infection. HBcAg‐specific interleukin‐21‐producing CD4+ T cells in blood were detected in patients with hepatitis B virus infection. Patients with acute hepatitis B had greater HBcAg‐specific interleukin‐21‐producing CD4+ T cells in blood compared with chronic hepatitis B patients, and there was no statistical significance between immune active chronic hepatitis B patients and inactive healthy carrier patients for these cells, whereas frequencies of these cells negatively correlated with HBV DNA levels but positively correlated with HBc18‐27‐specific IFN‐γ‐producing CD8+ T cells. Moreover, interleukin‐21 sustained HBc18‐27‐specific CD8+ T cells in vitro, and interleukin‐21 production by HBcAg‐specific IL‐21‐producing CD4+ T cells of acute hepatitis B patients enhanced IFN‐γ and perforin expression by CD8+ T cells from chronic hepatitis B patients. Our results demonstrate that HBcAg‐specific interleukin‐21‐producing CD4+ T cell responses might contribute to viral control by sustaining CD8+ T cell antiviral function.     

Hepatitis B core antigen stimulates interleukin-10 secretion by both T cells and monocytes from peripheral blood of patients with chronic hepatitis B virus infection

In chronic hepatitis B virus (HBV) infection, immune responses to hepatitis B core antigen (HBcAg) are weak. Interleukin (IL)-10 is a potent immunosuppressive cytokine which we reported recently to be secreted in response to HBcAg by peripheral blood mononuclear cells (PBMCs) from patients with chronic HBV infection or healthy controls. Using an enzyme-linked immunospot assay, we compared the ability of HBcAg to stimulate IL-10 production by PBMC with that of lipopolysaccharide (LPS), phytohaemagglutinin-P and hepatitis C virus-derived antigens in 16 patients with chronic HBV infection and six healthy controls. Frequencies of IL-10 spot-forming cells (SFC) in response to HBcAg were comparable to those obtained with LPS in patients with chronic HBV infection. Frequencies of IL-10 SFC in response to HBcAg or to LPS were significantly higher in patients with chronic HBV infection than in healthy controls. IL-10 SFC in response to HBcAg consisted of 26-35% T cells, 62-70% monocytes and less than 1% B cells in patients with chronic HBV infection. Only monocytes contributed to IL-10 production in controls. Frequencies of HBcAg stimulated IL-10 SFC representing T cells and monocytes were significantly higher in patients with elevated serum alanine aminotransferase (ALT) and detectable HBV DNA than in patients with normal ALT and undetectable HBV DNA. The potent ability of HBcAg to stimulate IL-10 production by PBMC may contribute importantly to immune tolerance toward HBV.     

不同种类乙型肝炎表面抗原诱导小鼠早期细胞免疫应答的比较

目的 比较不同表达系统来源的乙型肝炎(乙肝)表面抗原(HBsAg)免疫小鼠诱导早期脾淋巴细胞抗原特异性细胞免疫应答的特点,探讨影响乙肝疫苗保护效果的因素.方法 3种HBsAg(汉逊酵母、CHO细胞和血源)分别皮下接种不同组小鼠(BALB/c,H-2d),每只3μg,于免疫后4d分离脾单个核细胞(MNC),经细胞分选仪(MACs)分选后,获得纯度高于90％的CD4+和CD8+T细胞,应用ELISPOT测定MNC、CD4+和CD8+T细胞体外刺激后所产生的细胞因子IFN-γ、IL-2斑点数( SFC).结果 细胞分选后,汉逊抗原诱导CD8+T细胞分泌IFN-γ的水平和CD4+T细胞分泌IL-2水平均显著高于CHO抗原组(8/10、2/10,P=0.035;6/10、0/10,P=0.005).汉逊抗原组与血源抗原组CD8+T细胞经体外刺激诱导IFN-y全部阳转(10/10),但分泌水平上汉逊抗原组显著高于血源抗原组(t=2.479,P=0.035);汉逊抗原组诱导CD4+T细胞IFN-γ阳转率及分泌水平均显著高于血源抗原组(10/10、4/10,P=0.005;t=3.967,P=0.003).结论 乙肝抗原免疫小鼠4d即可诱导细胞免疫应答,且汉逊酵母抗原早期诱导抗原特异性IFN-γ、IL-2的能力显著高于CHO和血源抗原,与其临床考核母婴传播阻断HBV保护率显著优于CHO和血源乙肝疫苗相一致,为及时接种乙肝疫苗的必要性和高危新生儿选择接种乙肝疫苗的类型提供依据.     

Co-expression of markers for hepatitis delta and hepatitis B viruses in human liver

Delta hepatitis (HDV) infection can only occur in the presence of hepatitis B (HBV) infection, as HDV requires a coat of HBV surface antigen (HBsAg) for assembly of complete virus. A number of studies have examined the variation of HBV markers in serum and liver during establishment of HDV infection, but none has systematically examined the relationship between the two viruses in individual hepatocytes. Liver biopsies from five patients with HDV/HBV infection were stained for HBsAg, HBV core antigen (HBcAg) and hepatitis D (delta) antigen (HDAg). Double immunostaining was performed with a combination of indirect immunoperoxidase and alkaline phosphatase/antialkaline phosphatase techniques. HDV and HBV antigens were expressed in all five liver biopsies. Co-localization of HBsAg was seen in up to 39% of HDAg positive cells, and HBcAg in up to 8% of HDAg positive cells. HBcAg was detectable in approximately 9% of HBsAg positive cells, and HBsAg in approximately 12% of HBcAg positive cells. HDV can replicate without HBV but ultimately requires HBV to produce complete virus and subsequently infect other cells. In this study the majority of HDV positive cells did not appear to contain HBV markers. This might suggest delta virus replication without assembly, or possibly sequential production/assembly of the virus.     

Cellular immunity to nucleocapsid and pre-S determinants in asymptomatic carriers of hepatitis B virus.

Previous studies of cellular immunity in asymptomatic HBV carriers have been limited to evaluation of responses to plasma-derived HBsAg preparations. We have explored the specificity of cellular immune responses to HBV antigens in these subjects using an indirect T-lymphocyte migration inhibitory factor assay and three antigen preparations (recombinant nucleocapsid antigen (HBcAg), plasma-derived HBsAg with or without pre-S2, and Saccharomyces cerevisiae-synthesized HBsAg without pre-S2 region). T cells from 10 asymptomatic chronic HBV carriers with normal liver function tests were responsive to nucleocapside determinants (mean migration index = 0.55 +/- SD 0.07) and to pre-S2-positive plasma-derived HBsAg (MI = 0.62 +/- 0.05). However, none responded to HBsAg devoid of pre-S2 sequences (MI = 0.98 +/- 0.04). In further experiments, T cells from three HBV carriers, cultured with six different HBsAg preparations, exhibited responsiveness only to those preparations containing significant pre-S2 activities. Our results show that T-cell immunity to nucleocapsid determinants of the virus and HBsAg in present in asymptomatic HBV carriers; the latter is restricted to antigenic preparations containing significant pre-S2 activities. Hence, T-cell immunity to pre-S determinants may not always be associated with HBV clearance.