肝炎肝硬化患者外周血自然杀伤细胞的变化与HLA-Cw基因型相关性研究

目的 研究乙型肝炎病毒(HBV)引起的肝炎肝硬化和急性乙型肝炎患者外周血自然杀伤细胞(NK)和活化NK细胞数量的变化及其与HLA-Cw基因型的关系.方法 选择肝炎肝硬化和急性乙型肝炎发病期患者各30例及健康对照者41例,采用流式细胞仪检测外周血NK细胞和活化NK细胞的数量,并通过PCR-SSO(polymerase chain reaction-sequence specific oligonucleotide)的方法进行HLA-Cw的基因分型.结果 肝炎肝硬化组NK细胞和活化NK细胞的数量分别是13.22%±4.61%和45.68%±14.64%,均低于健康对照组(P<0.05),急性乙型肝炎组NK细胞和活化NK细胞的数量分别是22.62%±3.70%和65.28%±14.45%,均较健康对照组增高(P<0.05),且肝炎肝硬化组与急性乙型肝炎组比较差异有统计学意义(P<0.01);HLA-Cw*15在肝炎肝硬化组中基因频率明显高于健康对照组(P<0.05),且与活化NK细胞数量呈显著负相关(r=-0.862,P<0.05),急性乙型肝炎组与健康对照组间HLA-Cw位点各等位基因的基因型差异无统计学意义(P>0.05).结论 肝炎肝硬化患者NK细胞功能低下,HLA-Cw*15基因型可能是通过影响NK细胞而导致HBV感染持续存在的原因之一.     

慢性乙肝患者杀伤性免疫细胞功能的研究

通过对４４例病毒性肝炎患者Ｔ细胞亚群，ＮＫ细胞活性与ＬＡＫ细胞活性的观察，探讨了在慢性乙型肝炎病毒复制与非复制状态下的杀伤性细胞活性。结果表明：在乙肝病毒的高复制状态下，ＣＤ８＾＋细胞数增加，ＣＤ４＾＋／ＣＤ８＾＋比例显著下降；ＮＫ细胞活性与ＬＡＫ细胞活性也明显低下，且在ＨＢｅＡｇ与ＨＢＶＤＮＡ阳性组中，ＮＫ活性与ＬＡＫ活性的改变与ＨＢｅＡｇ的Ｐ／Ｎ值变化呈显著负相关，而ＮＫ活性与ＬＡＫ活性变化则     

Activated natural killer cells accelerate liver damage in patients with chronic hepatitis B virus infection

Emerging evidence indicates that natural killer (NK) cells may contribute to liver injury in patients with hepatitis B virus (HBV) infection. Because HBV infection progresses through various disease phases, the cytolytic profiles of peripheral and intrahepatic NK cells in HBV‐infected patients remain to be defined. In this study, we comprehensively characterized intrahepatic and peripheral NK cells in a cohort of HBV‐infected individuals, and investigated their impact on liver pathogenesis during chronic HBV infection. The study population included 34 immune‐clearance (IC) patients, 36 immune‐tolerant (IT) carriers and 10 healthy subjects. We found that the activity of peripheral NK cells from IC patients was functionally elevated compared to IT carriers and controls, and NK cell activation was indicated by an increased expression of CD69, CD107a, interferon (IFN)‐γ and tumour necrosis factor (TNF)‐α. Further analysis showed that the increased activity of both peripheral and hepatic NK cells was correlated positively with liver injury, which was assessed by serum alanine aminotransferase levels (ALT) and the liver histological activity index (HAI). Interestingly, the frequency of peripheral NK cells was reduced in IC patients (especially those with higher HAI scores of 3–4), but there was a concomitant increase in hepatic NK cells. The functionally activated NK cells are enriched preferentially in the livers of IC patients and skew towards cytolytic activity that accelerates liver injury in chronic hepatitis B (CHB) patients.     

Suppressed natural killer cell activity in patients with euthyroid Graves' ophthalmopathy

The purpose of the present study was to determine whether patients with euthyroid Graves' exophthalmopathy have an impaired NK cell function compared to patients with Graves' hyperthyroidism and healthy controls. The NK cell activity measured against K562 target cells was significantly suppressed (p less than 0.01) in patients with euthyroid Graves' ophthalmopathy, whereas the NK cell activity of patients with Graves' hyperthyroidism was not. Although interferon-alpha, interleukin-2 and indomethacin significantly enhanced (p less than 0.01) the NK cell activity in all three groups, none of these agents fully restored the defective NK cell activity in euthyroid Graves' ophthalmopathy. The concentrations in the blood of large granular lymphocytes and CD16 positive cells did not differ between the three groups, furthermore an immunosuppressive serum factor was not detected. The number of effector/target cell conjugates did not differ between patients and controls, whereas the interferon-alpha induced production of a soluble natural killer cytotoxic factor (NKCF) with specificity for NK sensitive target cells was suppressed in patients with Graves' euthyroid ophthalmopathy. We conclude that one of the mechanisms underlying the defective NK cell activity in patients with euthyroid ophthalmopathy may be an impairment of the release of NKCF from the NK cells.     

Autoantibodies as Predictive and Diagnostic Markers of Idiopathic Inflammatory Myopathies

The purpose of the present study was to determine whether patients with euthyroid Graves’ exophthal-mopathy have an impaired NK cell function compared to patients with Graves’ hyperthyroidism and healthy controls.

The NK cell activity measured against K562 target cells was significantly suppressed (p < 0.01) in patients with euthyroid Graves’ ophthalmopathy, whereas the NK cell activity of patients with Graves’ hyperthyroidism was not. Although interferon-α, interleukin-2 and indomethacin significantly enhanced (p < 0.01) the NK cell activity in all three groups, none of these agents fully restored the defective NK cell activity in euthyroid Graves’ ophthalmopathy. The concentrations in the blood of large granular lymphocytes and CD 16 positive cells did not differ between the three groups, furthermore an immunosuppressive serum factor was not detected. The number of effector/target cell conjugates did not differ between patients and controls, whereas the interferon-α -induced production of a soluble natural killer cytotoxic factor (NKCF) with specificity for NK sensitive target cells was suppressed in patients with Graves’ euthyroid ophthalmopathy. We conclude that one of the mechanisms underlying the defective NK cell activity in patients with euthyroid ophthalmopathy may be an impairment of the release of NKCF from the NK cells.     

Effect of zinc administration on cadmium-induced suppression of natural killer cell activity in mice

Natural killer (NK) cells play an important role in immune surveillance against viral infections and neoplasms. The effect of cadmium with or without zinc on mouse spleen NK cell activity was studied. Six-week-old male C57BL/6 mice were given drinking water containing either 50 ppm cadmium, 50 ppm cadmium together with 500 ppm zinc, or 500 ppm zinc. A fourth group receiving no additional cadmium or zinc served as control. After 3 weeks of treatment, the mice were killed, splenic lymphocytes isolated and cultured with 51Cr-labelled YAC-1 target cells for 4 and 12 h in a ratio of 50:1. The percentage of target cell lysis was measured to assess NK cell activity. In the 12-h assay, cadmium-treated animals had significantly lower NK cell activity than controls. Concurrent zinc administration prevented the suppression. In the 4-h assay, a similar trend was observed. Between 4 and 12 h, NK cell activity increased significantly in control and zinc-treated groups, but not in those receiving cadmium. The results suggest that a relatively low dose of cadmium suppresses NK cell activity, which can be prevented by a moderately large dose of zinc.     

Natural killer and activated killer activities in chronic liver disease and hepatocellular carcinoma: evidence for a decreased lymphokine-induced activity of effector cells.

Natural killer (NK) and activated killer (AK) cells appear to be important in immunoregulation, elimination of virus-infected cells and resistance to tumours. NK activity against K 562 and AK activity against FL target cells of peripheral blood mononuclear cells (PBMC) from patients with chronic persistent hepatitis (CPH), chronic active hepatitis (CAH), liver cirrhosis (LC) and hepatocellular carcinoma (HCC) were investigated using 51Cr release assay. Spontaneous NK activity of patients with LC (P less than 0.05) and HCC (P less than 0.001) was decreased when compared to that of controls. The sera and PBMC from patients with low NK activity had no inhibitory effect on the NK activity of normal subjects. Indomethacin treatment significantly enhanced the NK activity of controls (P less than 0.05), whereas the drug did not affect that of patients with low NK activity. The percentages of PBMC that reacted with monoclonal antibodies anti-Leu-7 and anti-Leu-11a were similar in controls and patients. However, a Leu-11a+/Leu-7+ ratio, and NK activity of Leu-11+ and Leu-7+ cell-rich populations were significantly decreased in cirrhotic and HCC patients when compared to controls. Interleukin 2 boosted both NK and AK activities of patients, but to a lesser degree in comparison with those of controls when similarly stimulated. gamma-Interferon also significantly augmented NK and AK activities of patients, but the levels of cytotoxicity were lower in HCC patients (P less than 0.05) than those of controls. These findings suggest that the decreased NK and AK activities in chronic liver disease and HCC are due to an altered subpopulation ratio of NK cells and a functional defect of effector cells.     

Preferential apoptosis of CD56dim natural killer cell subset in patients with cancer

Natural killer (NK) cells (CD56(+)/CD3(-)) in the circulation of cancer patients were reported to have low NK activity and undergo spontaneous apoptosis. A possible relationship between apoptosis and impaired NK activity was studied by Annexin V-binding and NK-cell assays performed with peripheral blood mononuclear cells of patients with head and neck cancer (HNC), breast cancer (BC) and normal controls (NC). Cells stained with Annexin V (Anx) and antibodies to CD56, CD3, CD95, CD25, CD122 or CD132 were examined by flow cytometry. NK activity was tested against K562 targets in 4-h (51)Cr-release assays. The ratio of CD56(dim)/CD56(bright) NK cells was significantly different in patients vs. controls (10 vs. 16; p<0.01). A significantly greater percentage of CD56(dim) NK cells bound Anx in HNC patients (27+/-17%, median +/- SD) or BC (46+/-18%) than in NC (15+/-18%, p<0.04 and p<0.0002, respectively). CD56(dim) NK cells were preferentially targeted for apoptosis. NK activity was significantly lower in patients with HNC and BC than in NC (p<0.009). An inverse correlation between NK activity and the percent of Anx(+)CD56(dim) NK cells was observed in cancer patients (p =0.002) but not in NC. In patients, circulating CD56(dim) NK cells were targeted for apoptosis, leading to low levels of NK activity.     

Surface markers of NK cells in peripheral blood of patients with cirrhosis and hepatocellular carcinoma

The surface markers and NK activity of blood lymphocytes in 38 normal controls, 57 cirrhotic patients and 22 cirrhotics with hepatocellular carcinoma were studied by the flow cytofluorometry using monoclonal antibodies. A reduction of OKM1+ cells was remarkable in cirrhotics, and a further decrease in HNK-1+ cells as well as OKM1+ cells was observed in cirrhotics with hepatocellular carcinoma, accompanied by depression of NK activity. We postulate that the decreased NK activity in these patients may result from the disturbed maturation of NK cells.     

Expression of insulin-like growth factor II (IGF–II) in human hepatocellular carcinomas: An immunohistochemical study

Recent results obtained using molecular biology techniques have suggested a possible role for insulin-like growth factor II (IGF-II) in the pathogenesis of hepatocellular carcinoma (HCC). To investigate this phenomenon, a monoclonal anti-body was used against IGF-II to study 54 patients with HCC. The presence of HBsAg was also tested both in serum and liver tissue. A positive immunoreaction was found in 9/15 (60%) of the HCC arising in cirrhotic livers of patients who had serum markers for HBV (HBV+ positive patients). These results provide further evidence that HBV might play a role in the expression of IGF-II. In HCC of patients without any markers of HBV infection (HBV- negative patients), IGF–II was detected in 10/39 (25.6%) of the tumors, and in some benign neoplastic lesions. It was found not only in neoplastic cells but also in some dysplastic nodules. The speculation arises that IGF–II expression may play a role in some steps of hepato-carcinogenesis.     

Up-regulate HLA Class I Expression Following Hepatitis B Virus Transfection in a Hepatocellular Carcinoma Cell Line BEL7405

Chronic hepatitis B virus infection is associated with a high risk of developing into hepatocellular carcinoma, while tumor recognition is important during the immune surveillance process that prevents cancer development in humans. The mechanisms of immune evasion and the role of the early immune response in chronic infection caused by hepatitis B virus (HBV) are still unclear. In the present study, 1 copy or 1.2 copies of HBV genome was transfected into a hepatocellular carcinoma cell line BEL7405. RT-PCR, Western blot and flow cytometry analysis were used to evaluate the expression of HLA class I molecules and transporter associated with antigen processing 1 (TAP1). Finally, the cytotoxic activity of natural killer (NK) cells against HBV transfected liver cells was detected by MTT colorimetry method. Following transfection of 1 copy or 1.2 copies of HBV genome, HLA class I expression was up-regulated in BEL7405 cell line in a dose-dependent manner. Furthermore, increased the surface HLA class I expression were caused by enhanced expression of TAP1 at mRNA and protein levels in those transfected cells. Consequently, a significantly down-regulated cytotoxic activity of NK cells against HBV transfected liver cells was observed. These results may demonstrate a way by which HBV avoids recognition by NK cells that might be associated with the establishment of chronic infection and tumor formation.     

Impaired release of natural killer cytotoxic factor in patients with primary Sjögren''s syndrome.

The impaired natural killer (NK) cell activity against K562 target cells of patients with primary Sjögren''s syndrome (primary SS) was re-examined in a 2-year follow-up study of 10 patients and 10 normal controls. The ability of blood mononuclear cells (BMNC) to form effector/target cell conjugates and to release NK cytotoxic factor (NKCF) were studied. NK cell activity of the patients was unchanged low (P less than 0.01) compared with the controls. The number of effector/target cell conjugates did not differ between patients and controls, whereas NKCF-release from interferon-stimulated BMNC was significantly (P less than 0.01) reduced in the patients with primary SS and positively correlated to the reduced NK cell activity (r = 0.85, P = 0.0002). The permanently low NK cell activity of patients with primary SS appears therefore, at least in part, to be due to an impaired release of NKCF and not to a defective ability of effector cells to recognize and/or adhere to target cells.     

Characterization of the natural killer cell activity in Hashimoto's and Graves' diseases

Natural killer (NK) cell activity and blood mononuclear cell subpopulations were characterized in patients with Hashimoto's thyroiditis ( n = 11), Graves' disease ( n = 20), non-toxic goitre ( n = 10) and in normal controls ( n = 22). NK cell activity against K 562 target cells and the capability of IFN-α, Il-2, and indomethacin to enhance NK cell activity in vitro did not differ significantly between the groups. The percentages of large granular lymphocytes, CD5 +, CD4 +, CD8 + and CD16 + cells were normal in patients with non-toxic goitre, Hashimoto's and Graves' diseases. There was no correlation between NK cell activities and TgAb, MAb and TSAb. Although NK cell activity is suppressed in several autoimmune diseases, NK cell function is normal in patients with autoimmune thyroid disorders.     

Effect of alcohol on the development of hepatocellular carcinoma in patients with hepatitis B virus-related cirrhosis: a cross-sectional case-control study

Background/Aims

Whether alcohol intake increases the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B virus (HBV) infection remains controversial. The aim of this study was to determine the effect of alcohol intake on the development of HCC.

Methods

Between January 2006 and August 2008, 146 patients with an initial diagnosis of HCC who were hospitalized in 3 major hospitals in the Incheon area were enrolled as cases. Another 146 cirrhotic patients, who matched the cases by age and sex, were enrolled as controls. All cases and controls were HBsAg positive, and had a history of lifetime alcohol intake.

Results

The cases and controls were aged 53±8 and 53±9 years (mean±SD), respectively, with each group comprising 118 males and 28 females. The basal laboratory data, distribution of Child-Pugh class, HBeAg positivity (31.5% vs. 37.7%), HBV DNA level (5.74±2.35 vs. 5.98±2.29 log₁₀ copies/mL), and proportion with a lifetime alcohol intake of more than 292 kg (30.8% vs. 34.9%) did not differ between cases and controls. The cumulative alcohol intake and the proportion of heavy drinkers did not differ between the two groups in male patients.

Conclusions

Alcohol intake might not increase the risk of HCC in patients with HBV infection.     

Occult hepatitis B virus infection and clinical outcomes of patients with chronic hepatitis C

Although occult hepatitis B virus (HBV) infections in individuals without detectable hepatitis B surface antigen (HBsAg) may occur and have been reported to be common in patients with chronic hepatitis C, the clinical relevance remains controversial. We searched for serum HBV DNA in 210 HBsAg-negative patients with hepatitis C virus (HCV)-related liver disease (110 patients with chronic hepatitis, 50 patients with cirrhosis, and 50 patients with hepatocellular carcinoma) by PCR. Most of the patients had detectable antibodies to HBsAg or HBV core antigen. All of the 110 chronic hepatitis C patients were treated with a combination therapy consisting of interferon plus ribavirin. In addition, 100 HBsAg-negative healthy adults served as controls. Thirty-one of the 210 patients (14.8%) had HBV DNA in their sera, as did 15 of the 100 healthy controls (15%). HBV DNA was not detected in the sera of those negative for serological markers of HBV infection. In patients with chronic HCV infection, the prevalence of occult HBV infection did not parallel the severity of liver disease (14.5% in patients with chronic hepatitis, 8% in patients with liver cirrhosis, and 22% in patients with hepatocellular carcinoma). In addition, the sustained response to combination therapy against hepatitis C was comparable between patients with and without occult HBV infection (38 versus 39%). In conclusion, these data suggest that occult HBV infection does not have clinical significance in chronic hepatitis C patients residing in areas where HBV infection is endemic.     

Natural killer activity and antibody-dependent cellular cytotoxicity in patients with adult T-cell leukemia

Natural killer (NK) activity of peripheral mononuclear cells (PMNC) from patients with adult T-cell leukemia (ATL), anti-HTLV-I antibody positive healthy carriers, and anti-HTLV-I antibody negative healthy persons (Ab-negative persons) was investigated using various target cells. PMNC from patients with ATL and healthy carriers had reduced NK activity against the NK-sensitive non-HTLV-I producing target cells, compared with the controls. In contrast, PMNC from patients with ATL, healthy carriers, and Ab-negative persons did not exhibit significant NK cell lysis against HTLV-I producing cells. However, one Ab-negative person exhibited increased NK cell lysis against an HTLV-I producing target cell. The effector cells involved in this enhanced cytolysis were found to be CD3+, HNK-1+, and CD8+. HTLV-I producing cells were lysed by PMNC from Ab-negative persons in the presence of anti-HTLV-I antibody (antibody-dependent cellular cytotoxicity; ADCC). The efficiency did not show significant difference between antibodies from patients with ATL and those from healthy carriers. The ADCC was specific to HTLV-I producing cells. PMNC from one patient with ATL in remission exhibited increased ADCC in the presence of autologous serum against HTLV-I, whereas PMNC from a patient with ATL or a healthy carrier did not exhibit ADCC. These results indicated that NK and K cells influence the immunological surveillance against HTLV-I infection or leukemic cells.     

Defective NK cell activity following thermal injury.

Peripheral blood mononuclear lymphocytes (PBL) from thermal injury patients were examined for their ability to mediate natural killer (NK) cell activity against K562 tumour cells and against herpes simplex virus type 1 (HSV-1) infected Raji tumour cells. Using fluorescein isothiocyanate-conjugated monoclonal antibodies, the number of T3, T4, T8, Leu11, and Leu7 positive cells in PBL obtained from patients and normal controls was determined. Thermal injury patients had decreased levels of T3+ cells and a T4:T8 ratio which was significantly lower than that found in normal control individuals. Although patients had normal percentages of Leu7+ and Leu11+ cells, they had depressed NK cell activity against both K562 tumour cells and HSV-1 infected Raji cells. NK cell activity against K562 tumour cells was severely depressed during the first 20 days after injury. This defective NK cell activity did not appear to be due to a defect in PBL binding to the K562 tumour cells. In patients, the level of NK cell activity against HSV-1 infected cells did not correlate with the level of NK cell activity against K562 tumour cells. This finding further supports previous reports showing that NK cells which kill K562 tumour cells are different from the NK cell population which kills HSV-1 infected cells. Pretreatment of PBL obtained from patients with IL-2 or IFN-alpha, in some cases greatly enhanced NK cell killing of K562 tumour cells. However, IL-2 or IFN-alpha did not enhance NK cell activity in patients who had severely depressed levels of NK cell activity. Interestingly, in some patients, differential responsiveness to IL-2 and IFN-alpha was observed. In some patients, NK cell activity was enhanced by IL-2 but not by IFN-alpha. These results, while only suggestive, may indicate that different populations of NK cells respond preferentially to IL-2 and that IFN-alpha and/or IL-2 enhance NK cell activity in PBL obtained from some, but not all, thermal injury patients. Finally, this study clearly shows that thermal injury patients have defective NK cell activity not only against K562 tumour cells but also against virus-infected cells.     

Sequencing of human-viral DNA junctions in hepatocellular carcinoma from patients with HCV and occult HBV infection

DNA of free hepatitis B viruses (HBV) has been detected in the liver of patients infected with hepatitis C virus (HCV). It is unknown whether HBV DNA is integrated into such livers; if so, it may affect hepatocarcinogenesis. Hepatocellular carcinomas (HCCs) from 34 patients without HBV surface antigen (HBsAg) and with anti-HCV, and from 7 patients with HBsAg and without anti-HCV as controls, were examined, using the cassette-ligation-mediated polymerase chain reaction and primers based on HBV DNA sequence. In the controls, HBV DNA had been integrated into human DNA of all HCCs. On the basis of HBV DNA in tumor tissue, 23 of the 34 patients with anti-HCV had occult infection. Junctions between human DNA and HBV DNA were detected in 10 of the 34 patients without HBsAg and with anti-HCV. HBV DNA was integrated into chromosome 11q in 4 of the 10 HCCs with junctions. The DNA to either side of the human-viral junctions was sequenced. Clinically, the mean tumor size of these 10 HCCs was 39 mm; that of the 24 HCCs without integrated HBV was 25 mm. The surrounding tissue was cirrhotic in 2 of the 10 former HCCs and in 16 of the latter 24 HCCs. In conclusion, integrated HBV was detected in some patients with HCV infection; in these patients, the integrated DNA was associated with accelerated hepatocarcinogenesis.     

Natural killer (NK) cell activity during HIV infection: a decrease in NK activity is observed at the clonal level and is not restored after in vitro long-term culture of NK cells.

NK cell activity is impaired in HIV-infected patients. The mechanisms behind the altered NK functions are not clear, and conflicting data concerning NK and antibody-dependent cellular cytotoxicity (ADCC) activity have been reported. In order to investigate whether this impairment is also observed at the clonal level and whether it is related to a defect at the target cell binding and/or the post-binding level, we evaluated highly purified NK cell lines and cloned NK cells obtained from 22 HIV-infected patients at different stages of disease and compared them with normal controls for their ability to: (i) kill K-562 and U-937 cell lines using a 51Cr release assay; (ii) bind and kill K-562 and U-937 cells at the single cell binding level; (iii) release NK cytotoxic factor (NKCF), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma); (iv) kill anti-IgM preincubated Daudi cell line (ADCC activity). This study with cloned NK cells or NK cell lines from HIV-infected individuals showed: (i) a decrease in their lytic capability against target cell lines; (ii) a low ability to form conjugates with K-562 and U-937 cell lines with respect to controls; (iii) a decreased ability to kill bound target cells; (iv) low levels of released NKCF, TNF-alpha and IFN-gamma after incubation with U-937 cells. Taken together, these findings suggest that the impaired NK cell function during HIV infection is also observed at the clonal level and is related to defects both at the target and post-binding levels. However, the precise mechanisms remain to be determined. The inability to restore normal NK activity after long-term culture in the presence of high levels of recombinant IL-2 is in agreement with the hypothesis of a 'general anergic process' during HIV infection.     

某些肝病患者外周血单个核细胞天然杀伤(NK)活性的探讨

目前认为,NK细胞可能参与构成机体抗肿瘤生长和病毒感染的第一道防线。对许多恶性肿瘤患者的研究表明,其外周血NK活性低下,且与肿瘤进展和转移有关。但对病毒感染患者NK活性变化研究尚少,结果也不一致。一般认为,乙型病毒性肝炎和肝硬化(LC)可演变成肝细胞性肝癌(HCC)