CD4+/CD8+ ratio of liver-derived lymphocytes is related to viraemia and not to hepatitis C virus genotypes in chronic hepatitis C.

The pathogenic mechanisms that lead to chronic hepatitis C are unknown. As hepatitis C virus (HCV) has been shown to induce T cell response, we assessed whether a particular T lymphocyte subset could be preferentially detected in the liver of patients with chronic hepatitis C in relation to viraemia or HCV genotypes. The immunophenotypes of liver-derived lymphocytes were analysed in 26 patients by flow cytometry and immunohistochemistry. Viraemia was quantified by branched DNA assay. Using this assay, HCV RNA was not detectable in six patients. HCV RNA was detected in 20 patients, and titres ranged from 8 to 137 x 10(6) Eq/ml. Genotyping was performed using a line probe assay. Type 1a, 1b, 2a, 3a and 4a were found to infect 2, 10, 2, 7 and 3 patients, respectively. The CD4+/CD8+ ratio of liver-derived lymphocytes was significantly higher (P < 0.01) in patients with detectable viraemia than in patients without detectable viraemia. In contrast, neither the percentage of gamma/delta T lymphocytes nor that of CD2+CD57+ cells was different in the groups. When comparing the CD4+/CD8+ ratio, the percentage of gamma/delta T lymphocytes or CD2+CD57+ cells according to genotype, the differences were not significant. These results suggest that the CD4+/CD8+ ratio of liver-derived lymphocytes is related to viraemia but not to HCV genotypes in patients with chronic hepatitis C, and that T lymphocytes may be involved in the pathogenesis of liver lesions in chronic hepatitis C.     

CD8+ lymphocytes but not B lymphocytes are required for protection against chronic hepatitis E virus infection in chickens

Hepatitis E is an important global disease, causing outbreaks of acute hepatitis in many developing countries and sporadic cases in industrialized countries. Hepatitis E virus (HEV) infection typically causes self-limiting acute hepatitis but can also progress to chronic disease in immunocompromised individuals. The immune response necessary for the prevention of chronic infection is T cell-dependent; however, the arm of cellular immunity responsible for this protection is not currently known. To investigate the contribution of humoral immunity in control of HEV infection and prevention of chronicity, we experimentally infected 20 wild-type (WT) and 18 immunoglobulin knockout (JH-KO) chickens with a chicken strain of HEV (avian HEV). Four weeks postinfection (wpi) with avian HEV, JH-KO chickens were unable to elicit anti-HEV antibody but had statistically significantly lower liver lesion scores than the WT chickens. At 16 wpi, viral RNA in fecal material and liver, and severe liver lesions were undetectable in both groups. To determine the role of cytotoxic lymphocytes in the prevention of chronicity, we infected 20 WT and 20 cyclosporine and CD8⁺ antibody-treated chickens with the same strain of avian HEV. The CD8 ⁺ lymphocyte-depleted, HEV-infected chickens had higher incidences of prolonged fecal viral shedding and statistically significantly higher liver lesion scores than the untreated, HEV-infected birds at 16 wpi. The results indicate that CD8 ⁺ lymphocytes are required for viral clearance and reduction of liver lesions in HEV infection while antibodies are not necessary for viral clearance but may contribute to the development of liver lesions in acute HEV infection.     

Ordered array of dendritic cells and CD8+ lymphocytes in portal infiltrates in chronic hepatitis C

AIMS: Despite the importance of dendritic cells in stimulating primary and secondary immune responses by presenting antigens to T-lymphocytes in draining lymph nodes and peripheral tissues, respectively, very limited information is available on the presence and localization of these cells in hepatitis C virus (HCV)-related chronic active hepatitis. Therefore, we addressed the ultrastructure, immunophenotype, distribution and relationships to lymphatics of dendritic cells in portal infiltrates of this disease. METHODS AND RESULTS: Part of percutaneous diagnostic liver biopsies (Knodell's histological assessment index: 9-13) was processed for electron microscopy and for immunohistochemical detection of immune system cell membrane antigens and of the lymphatic endothelium marker podoplanin. In portal infiltrates, cells with electron microscopical and cell marker features of dendritic cells and expressing the activation markers CD54, CD80, CD83 and CD86 were organized in a discontinuous network, that embedded CD8+ lymphocytes in close contact with dendritic cells and came in contact with hepatocytes, sometimes infiltrating beyond the limiting plate. Also, dendritic cells were found within newly formed lymphatic capillaries in thin, infiltrated septa among hepatocytes. CONCLUSIONS: This evidence strongly suggests a critical role of dendritic cells and newly formed lymphatics in the pathogenesis and organization of the immune infiltrate that characterizes HCV-related chronic active hepatitis.     

Analysis of the complete hepatitis B virus genome in patients with genotype C chronic hepatitis in relation to HBeAg and anti-HBe

To investigate the relationship between viral factors and the development of chronic hepatitis B, the entire hepatitis B virus (HBV) genome of chronic carriers at different disease stages were analyzed. Eighty genotype C HBV carriers including 12 hepatitis B e antigen (HBeAg) positive asymptomatic carriers (Group A), 49 HBeAg positive patients with chronic liver diseases (Group B) and 19 anti-HBe positive patients with chronic liver diseases (Group C) were studied. HBV nucleic acid from serum samples was sequenced directly and compared with GenBank reference sequences HBV X01587 and M12906. On phylogenetic analysis, 76 cases were genotype C2. Of the 76 genotype C2 cases, the nucleotide and amino acid substitution rates in the precore/core region were significantly higher in Groups B and C than in Group A, also in Group C than in Group B. The nucleotide substitution rates in the full genome and the core promoter region were significantly higher in Group C than in Group A, also in group C than in Group B. The nucleotide and amino acid substitution rates in the X region were significantly higher in Group C than in Group A. The amino acid substitution rate in the pre-S2 region was significantly higher in Group C than in Group B. Deletion mutations were found mainly in Groups B and C. This whole genome analysis of HBV chronic carriers suggested that the nucleotide substitutions and deletions in HBV were closely associated with the pathogenesis of chronic HBV infection.     

慢性乙型肝炎患者外周血CD8+/CD28+淋巴细胞及其亚型的研究

目的 探讨慢性乙型肝炎患者外周血CD8+/CD28+淋巴细胞及其亚型与其临床状态和HBV复制的关系.方法 采用流式细胞技术多色荧光分析法,检测研究对象的外周血CD8+淋巴细胞、CD45RO、CD45RA以及CD28的表达及HBV病毒载量.结果 ①慢性HBV携带组CD8+淋巴细胞CD28的表达率(10.64±5.09%)明显低于慢性乙肝组和正常对照组;而CD45RA和CD45RO的表达差异无统计学意义;②慢性乙肝组CD8+/CD45RO+/CD28+的表达(10.99±7.33%)明显高于正常对照组,而慢性乙肝组和慢性HBV携带组CD8+/CD45RA+/CD28+表达率均明显低于正常对照组;③HBeAg阴性慢性乙肝CD8+/CD45RO+/CD28+表达率明显高于阳性组,而CD8+/CD45RA+/CD28+表达率两组无差别.结论 慢性HBV携带者处于病毒携带状态可能与CD8细胞上协同分子CD28的表达低下有关;CD8+/CD45RO+/CD28+亚型淋巴细胞数的升高与慢性乙肝的病情进展及血清HBeAg转换有关.     

Characterization of viral kinetics in patients with hepatitis B e antigen-positive chronic hepatitis B

A study was conducted during a 1 year follow-up to characterize the viral kinetics in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B and to develop a model of predicting the probability of spontaneous HBeAg seroconversion. Fifty-seven patients with HBeAg-positive chronic hepatitis B were enrolled with monthly follow-ups from three Phase III clinical trial placebo groups. According to serial viral loads, 30 patients (52.6%) with the stationary pattern maintained stable HBV DNA levels with fluctuations of less than 1.5 log copies/ml. Twenty patients (35.1%) with the declining pattern exhibited a spontaneous decline of more than 1.5 log copies/ml without a following rebound of at least 1.5 log copies/ml. The remaining seven patients (12.3%) had the wavering pattern. Both declining and wavering patterns, when compared with the stationary pattern, had significantly higher hepatic necroinflammation in terms of ALT and Knodell scores at the baseline and peak ALT levels during the follow-up period. The declining pattern had a significantly better clinical outcome in terms of the lowest final HBV DNA and a reduction in the necroinflammatory score after 1 year. Furthermore, the declining pattern had a favorable HBeAg seroconversion rate (40%) compared with the wavering (14.3%) and stationary patterns (0%). A regression equation, incorporating simultaneous serum bilirubin, ALT, and HBV DNA levels, predicted the probability of HBeAg seroconversion with a sensitivity of 76.8% and a specificity of 74.7%. In conclusion, different viral kinetic patterns in patients with chronic hepatitis B implicate distinct clinical significance and immunologic perspective.     

High levels of viral replication during acute hepatitis B infection predict progression to chronicity

To assess the pattern of development of serologic markers during acute hepatitis B, levels of HBsAg, HBeAg, and hepatitis B virus (HBV) DNA were assayed in stored serum samples obtained sequentially from 12 subjects infected with HBV during experimental studies conducted in the 1950s. Six patients developed acute self-limited hepatitis, three developed chronic hepatitis, and three had an asymptomatic infection without HBsAg. HBsAg was the first serologic marker detected (mean = 52 days after exposure), followed by HBeAg (62 days) and HBV DNA (72 days). Peak HBsAg levels occurred before onset of symptoms and correlated with peak titers of HBeAg and HBV DNA. Patients who developed chronic hepatitis had higher peak levels of viral markers than those with self-limited disease: HBsAg (30 versus 5.4 μg/ml), HBeAg (1:2,000 versus 1:60 titer) and HBV DNA (3,192 versus 444 pg/ml). Thus, chronic HBV infection is characterized by high levels of viral replication appearing early during the acute phase of infection. © 1994 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

聚乙二醇化干扰素α-2a对慢性乙型肝炎患者外周血T淋巴细胞亚群的影响

目的 动态观察慢性乙型肝炎患者(CHB)聚乙二醇化干扰素α-2a治疗过程中外周血T淋巴细胞亚群的变化及其临床意义.方法 给予52例CHB患者聚乙二醇化干扰素α-2a (PEG-IFNa-2a)抗病毒治疗48周.在治疗前、治疗12和48周,分别以流式细胞术检测外周血淋巴细胞亚群百分比和数量,全自动生化分析仪检测谷丙转氨酶...     

慢性HBV感染患者肝组织内CD4+CD25+调节性T淋巴细胞的表达

目的 观察慢性HBV感染患者免疫耐受期与免疫清除期肝组织中CD4+ CD25+调节性T细胞的表达及分布情况.方法 应用免疫组织化学法检测19例免疫耐受期及12例免疫清除期慢性乙型肝炎患者肝组织中FoxP3的表达,6例正常肝组织为对照.结果 FoxP3阳性信号位于淋巴细胞胞核内,阳性细胞主要聚集在汇管区,肝窦内亦可见散在单个淋巴细胞呈阳性.在免疫耐受期及免疫清除期患者肝组织中FoxP3较正常肝组织明显增加(P<0.01),免疫清除期患者肝组织内Fox P3明显高于免疫耐受期患者(P<0.01).免疫清除期患者肝组织中FoxP3阳性标记指数与ALT、HBeAg及HBV-DNA水平无明显相关性.免疫耐受期与免疫清除期两组相比,在年龄、ALT、TBIL、PTA、HBeAg及HBV-DNA水平方面差异均有统计学意义.结论 肝组织中CD4+ CD25+调节性T细胞在慢性HBV感染慢性化和抑制免疫,控制肝脏炎症反应方面可能起了重要作用.     

Intracellular antibody fragment against hepatitis B virus X protein does not inhibit viral replication

Replication of the hepatitis B virus is suppressed by deficiency of the X protein. Although several molecules that block cellular targets of X protein reduce the production of hepatitis B virus progeny, the effect of a specific inhibitor of X protein on viral replication has not been investigated. To block X protein specifically, we adopted an intracellular expression approach using H7 single chain variable fragment (H7scFv), an antibody fragment against X protein. We previously demonstrated that cytoplasmic expression of H7scFv inhibits X protein-induced tumorigenicity and transactivation. In this study, intracellular H7scFv expression inhibits reporter gene transactivation but not viral replication determined by endogenous hepatitis B virus polymerase activity assay and real-time PCR. Our findings imply that intracellular expression of antibody fragment against X protein may not be an alternative therapeutic modality for inhibition of hepatitis B virus replication.     

Circulating CD4+ CD25+ regulatory T cells correlate with chronic hepatitis B infection

Circulating CD4+ CD25+ regulatory T cells (Tregs) have been demonstrated to maintain immunotolerance and suppress the antigen-specific or antigen-non-specific T-cell responses, but their role in chronic hepatitis B (CHB) infection in humans has not been well characterized. In this study, we analysed the frequency and phenotypic characteristics of CD4+ CD25+ Tregs in patients of different hepatitis B virus (HBV) infection status, and investigated the effect of Tregs on antiviral immune responses in CHB patients, and the mechanism of this effect. A total of 137 subjects, including 79 CHB patients, 26 asymptomatic HBV carriers (ASCs), 12 acute hepatitis B (AHB) patients and 20 healthy controls, were enrolled in the study. We found that the frequency of CD4+ CD25(high) Tregs in AHB patients was comparable to that in healthy controls, while it was significantly increased in CHB patients. CD4+ CD25+ Tregs produced interleukin (IL)-10 but little or no interferon (IFN)-gamma under anti-CD3 stimulation. In CHB patients, the frequency of CD4+ CD25(high) Tregs positively correlated with serum viral load, and the Tregs were capable of suppressing the proliferation and IFN-gamma production of autologous peripheral blood mononuclear cells (PBMC) mediated by HBV antigen stimulation in vitro. However, combined administration of anti-programmed death-1 (PD-1) and anti-cytotoxic lymphocyte antigen-4 (CTLA-4) monoclonal antibody slightly enhanced the cellular proliferation and significantly increased the IFN-gamma production of PBMC cocultured with Tregs at a ratio of 2:1. Thus, the frequency of circulating CD4+ CD25+ Tregs is increased in patients with CHB, and this may play an important role in viral persistence by modulating virus-specific immune responses.     

不同亚群CD8＋T细胞细胞毒作用对慢性乙型肝炎的影响

目的观察慢性乙型肝炎不同分期及干扰素-a（interferon-a,IFN-a）治疗前后外周血不同亚群CD8＋T细胞细胞毒作用的变化,探讨其在慢性乙型肝炎发病机理及抗病毒治疗中的作用。方法采集20例慢乙肝免疫耐受期患者和20例免疫清除期患者IFN—a治疗前后的外周全血,采用流式细胞仪检测CD8^high和CD8^lowT细胞的颗粒酶B（Granzyme B,GrB）和溶酶体相关膜蛋白-1（Lysosome—associated membrane protein．1,LAMP-1,CD107a）表达变化,并进行分析。结果（1）慢乙肝患者免疫清除期不同亚群CD8＋T细胞GrB和CD107a的表达水平均高于免疫耐受期;（2）不同分期慢乙肝患者CD8^lowT细胞GrB和CD107a的表达水平均高于CD8^highT细胞;（3）IFN—a治疗后CD8^highT细胞的GrB和CD107a表达水平和治疗前相比具有升高趋势,而CD8^lowT细胞反而具有下降趋势;（4）不同亚群CD8＋T细胞的GrB和CD107a表达水平与HBV—DNA载量在免疫耐受期呈正相关,而在免疫清除期呈负相关。结论（1）不同亚群CD8＋T细胞的GrB和CD107a分子在慢乙肝疾病进程及抗病毒治疗中均起重要作用,CD8^lowT细胞的细胞毒作用强于CD8^highT细胞,而CD8^highT细胞的细胞毒效应在IFN—a治疗过程中逐渐增强。（2）不同亚群CD8＋T细胞的GrB和CD107a分子水平与HBV病毒载量的相关性在一定程度上可以提示机体免疫应答与病毒之间的关系。     

DNA structure in peripheral blood lymphocytes from patients with chronic viral liver damages

We studied DNA damages (single-strand breaks and alkali-labile sites) in peripheral blood lymphocytes from patients with chronic viral hepatitis and cirrhosis of mixed etiology. The structure of DNA was estimated fluorometrically by changes in the intensity of ethidium bromide fluorescence. Monoinfection with hepatitis B and C viruses was not accompanied by considerable changes in DNA structure in peripheral blood lymphocytes from patients with chronic diseases. The incidence of DNA damages in lymphocytes increased in patients with hepatitis G virus and TTV monoinfection. This is probably related to replication of these viruses in nucleated blood cells. Our results suggest that hepatitis C virus potentiates damaging effect of hepatitis G virus on DNA in lymphocytes.     

慢性乙型肝炎患者HBV特异性CTL、非特异性CTL的变化和意义

目的探讨慢性乙型肝炎(CHB)患者的外周血HBV特异性CTL、非特异性CTL的变化和意义。方法对80例人白细胞抗原(HLA)-A2阳性的CHB患者用流式细胞仪检测外周血HBV特异性CTL、非特异性CTL和T细胞亚群,对20例HLA-A2阳性的急性乙型肝炎(AHB)患者作HBV特异性CTL、非特异性CTL的检测,30例健康献血员作非特异性CTL和T细胞亚群的检测作为对照。结果80例CHB患者的HBV特异性CTL低于急性乙型肝炎患者,分别为(0.32±0.11)%和(1.1±0.31)%,t=7.704,P=0.000,非特异性CTL高于正常对照组,分别为(18.23±5.13)%和(15.83±4.99%),t=2.220,P=0.028。结论CHB患者的HBV特异性CTL较低,一方面是导致HBV慢性持续感染的主要原因,另一方面启动了非特异性CTL引起肝功能损害。     

慢性乙型肝炎患者外周血CD4~+CD25~+Treg与CD4~+和CD8~+ T淋巴细胞亚群的相关研究

目的:探讨慢性乙型肝炎患者外周血中CD4+CD25+调节性T细胞的含量和CD4+CD8+T淋巴细胞亚群分布,两者之间相关性及与HBV的相关性。方法:采用流式细胞术检测50例慢性乙型肝炎患者和20例健康对照者外周血中CD4+CD25high、CD4+CD25+Foxp3+Treg细胞表达及CD3/CD4/CD8 T淋巴细胞亚群,荧光定量PCR法检测HBV DNA含量。结果:慢性乙型肝炎患者外周血中CD4+CD25highTreg明显高于健康对照组(P0.01),且随HBV DNA载量增加,患者外周血中CD4+CD25highTreg细胞的水平逐渐升高。慢性乙型肝炎患者外周血中CD4+CD25+Foxp3+Treg细胞也相应增高,且与CD4+CD25highTreg细胞的变化成正相关(r=0.890,P0.001)。与健康对照组比较,患者组CD4+T细胞百分率及CD4+/CD8+比值均降低,而CD3+T细胞和CD8+T细胞百分率差异无显著性(P0.05)。CD4+CD25highTreg细胞与HBV DNA取对数后成正相关(r=0.782,P0.001),与谷丙转氨酶(ALT)成正相关(r=0.432,P0.005);与CD3+、CD4+、CD8+T细胞水平及CD4+/CD8+比值均无相关性(P0.05)。CD3+、CD4+、CD8+T淋巴细胞及CD4+/CD8+比值与HBV DNA载量之间亦无相关性(P0.05)。结论:慢性乙型肝炎患者外周血中CD4+CD25+Treg细胞增高,且与HBV的复制水平及ALT增高具有一致性,而T细胞亚群是否可作为监测CHB患者免疫状态的指标需进一步探讨。     

Changes in hepatitis B virus DNA-polymerase activity in patients with chronic infection

Levels of serum hepatitis B virus DNA-polymerase (HBV-DNAP) were studied longitudinally over variable periods of time in 16 HBV chronic carriers using a modified assay procedure developed to increase reproducibility. Ten patients were tested on a short-term basis at 3- to 6-hr intervals for 48 hr or at 24- to 48-hr intervals for 15 consecutive days, and all showed marked vacillations in enzyme levels although hospitalized and untreated. Patients with chronic active hepatitis on liver biopsy had larger fluctuations compared to cases of chronic persistent hepatitis. Six patients were longitudinally tested over a period of 12–32 months and those three receiving immunosuppressive drugs showed a progressive increase in DNAP levels during therapy, but two returned to pretreatment levels after therapy was withdrawn and one even cleared permanently the complete virus with seroconversion to anti-HBe. Such outcome was also observed in one patient with chronic active hepatitis who remained untreated.     

Inhibition of HIV replication by CD8+ T cells correlates with CD4 counts and clinical stage of disease.

We sought to evaluate the relationship of CD8+ T cell-mediated inhibition of autologous HIV replication in vitro to disease stage in HIV+ individuals. Depletion of CD8+ T cells from peripheral blood lymphocytes of 16 HIV+ subjects increased the percentage of virus-producing cultures from 56% to 81%. CD4+ T cells were purified from 52 HIV+ individuals and cultured alone or in the presence of autologous CD8+ T cells. In 13 (25%) subjects HIV replication was only detected in the absence of CD8+ T cells (inhibition positive); in 26 (50%) viral replication occurred both in the absence and presence of CD8+ cells (inhibition negative). In the remaining 13 (25%) subjects, CD8+ T cell-mediated inhibitory activity could not be evaluated because stimulation of their purified CD4+ T cells did not result in p24 production. In some virus culture-negative individuals, the inability to demonstrate HIV replication was due to the presence of low numbers of CD8+ T cells that co-purified with CD4+ T cells. Detection of inhibitory CD8+ T cells was associated with significantly higher CD4 counts and better clinical status compared with inhibition-negative subjects. These results demonstrate that CD8+ T cell-mediated inhibition of HIV replication correlates with disease stage, and thus may play a role in preventing disease progression. CD8+ T cells did not inhibit autologous HIV replication across a semipermeable membrane. Further, the ability of CD8+ T cells to prevent HIV replication did not correlate with lysis of autologous CD4+ T cells. Thus, CD8+ T cells inhibited autologous HIV replication in vitro through a contact-mediated non-lytic mechanism.