卵巢肿瘤患者外周血NK细胞受体NKG2A、NKG2D及NK活性检测的临床意义

通过研究卵巢癌及良性卵巢肿瘤患者外周血NK细胞表面受体的表达情况及NK活性的变化,分析探讨宿主NK细胞受体与肿瘤免疫逃逸的关系及其临床价值。分离受检者外周血单个核细胞,应用MTT法检测NK细胞的细胞毒活性,流式细胞术检测NK细胞受体NKG2D和NKG2A的表达,并结合临床病理因素作比较分析。结果显示,与良性卵巢肿瘤组和正常组相比,卵巢癌患者外周血NK细胞的细胞毒活性降低,NK细胞表面NKG2D的表达水平降低,而NKG2A的表达水平明显升高,其变化与卵巢癌的病情进展有关。此结果表明,卵巢癌患者机体NK细胞杀伤活性下降,NKG2D与NKG2A二者之间的平衡表达可能对NK细胞的功能状态起着重要的调节作用。     

妊娠期uNK、pNK细胞NKG2A与NKG2D的表达及其生物学意义的研究

目的:研究妊娠期妇女子宫NK细胞(uNK细胞)与外周血NK细胞(pNK细胞)表面NKG2A和NKG2D及其相应配体的表达,探讨uNK细胞表面NKG2A和NKG2D的不平衡表达与母胎界面所形成的免疫耐受关系。方法:采用流式细胞术检测30例孕6～9周的正常妊娠妇女uNK细胞和pNK细胞NKG2A、NKG2D的表达状况;RTPCR技术检测绒毛膜组织HLAE、MICA的表达。结果:子宫NK细胞NKG2A的表达显著高于外周血NK细胞,二者分别为(97.86±1.75)%与(33.35±10.92)%;子宫NK细胞NKG2D的表达水平与外周血NK细胞相近,分别为(93.21±4.52)%与(97.80±1.72)%,滋养层组织仅检测到HLAEmRNA的表达。结论:妊娠期子宫NK细胞表面高表达抑制性受体NKG2A,同时滋养层组织表达相应的配体HLAE,这可能是维持母胎界面免疫耐受的重要因素。     

HIV感染者T细胞NKG2C/NKG2A表达及与疾病进展关系研究

目的：研究HIV慢性感染者和HARRT治疗者T细胞NKG2C/NKG2A受体的表达变化,探讨其与疾病进展的关系。方法：选取HIV慢性感染者、接受HAART治疗的HIV感染者以及健康人的外周血细胞,通过荧光抗体染色,利用流式细胞仪检测T细胞上表达的NKG2C/NKG2A受体。结果：HIV慢性感染者NKG2C⁺ T细胞,NKG2A⁺ T细胞和NKG2C+NKG2A- T细胞百分比明显高于健康对照组 (P=0.025、P=0.032、P=0.029),HARRT治疗组则明显低于HIV慢性感染者(P=0.033、P=0.037、P=0.018),恢复到正常水平,与健康对照组相比无统计学差异。HIV慢性感染者外周血CD4⁺ T淋巴细胞绝对数和表达NKG2A、NKG2C⁺NKG2A⁺和NKG2C-NKG2A⁺ 的T细胞呈负相关(r=-0.697,P<0.000 1;r=-0.463,P=0.015;r=-0.693,P<0.000 1),HIV慢性感染者外周血T细胞上表达的NKG2C与NKG2A的比值与CD4⁺ T淋巴细胞绝对数呈正相关(r=0.476,P=0.012)。结论：HIV感染者T细胞表面NKG2C和NKG2A的表达研究具有重要意义,为HIV感染的临床预后评估提供科学依据。     

慢性乙型肝炎患者、HBV携带者及急性自限性HBV感染者外周血调节性T细胞的差异及意义

目的比较慢性乙型肝炎患者、HBV携带者、急性自限性HBV感染者与正常对照之间外周血调节性T细胞（Treg）比例的差异，分析HBV感染后不同临床转归与Treg的关系，为慢性乙型肝炎的治疗提供新的线索。方法选取2004年2月至10月在我院肝炎门诊就诊的慢性乙型肝炎患者28例、HBV携带者23例、急性自限性HBV感染者19例以及健康献血员14例，使用流式细胞仪检测其外周血Treg的比例，分析其差异及临床意义。结果慢性乙型肝炎组外周血Treg占CD4^＋T细胞的比例为7．2％±3．1％，较HBV携带者组、急性自限性HBV感染者组及正常对照组增高；而HBV携带者组、急性自限性HBV感染者组及正常对照组之间Treg比例差异无统计学意义。结论Treg在HBV感染后慢性化的过程中可能发挥了一定的作用。     

IL-2促进PBMC来源的NK、NKT、CD8+T细胞高表达NKG2D

目的 观察大剂量IL-2活化的人外周血单个核细胞（PBMC）中，NKG2D在NK细胞、T细胞和NKT细胞表面的表达规律。方法 使用三重免疫荧光标记的流式细胞术检测NKG2D的表达情况。使用sMICA蛋白与人PBMC共同培养，之后使用流式细胞术分析NKG2D在NK细胞中的表达情况。使用半定量RT-PCR方法检测大剂量IL-2活化的人PBMC中NKG2D及其锚定蛋白DAP10 mRNA的表达变化。结果 使用大剂量IL-2活化人PBMC细胞后，NKG2D在NK细胞、CD^＋T细胞和NKT细胞表面的表达均增加，但是在CD4^＋T细胞表面始终不表达。同时IL-2可以拮抗sMICA对NKG2D的下调作用。半定量RT-PCR结果显示，使用大剂量IL-2活化人PBMC之后，NKG2D及其锚定蛋白DAP10的mRNA水平并不发生明显变化。结论 大剂量IL-2培养人PBMC之后，NKG2D在NK细胞、CD8^＋T细胞和NKT细胞表面的表达均增加，可能是PBMC活化并获得广谱抗肿瘤效应的机制之一．     

慢性乙型肝炎患者外周血单核细胞与血清HBV DNA定量对比研究

目的　探讨慢性乙肝患者外周血单个核细胞 (PBMC)内HBV -DNA的出现与血清HBV -DNA浓度之间关系 .方法　应用荧光定量PCR技术检测 5 7例慢性乙肝患者血清和PBMC中HBV -DNA含量、对血清中不同的病毒浓度进行分组比较分析 .结果　① 5 7例PBMC内HBV DNA总检测出率为 4 2 .1% (2 4 / 5 7) ,两者检测结果一致占 88.6 % .②根据血清内HBV -DNA浓度分成三组 ,三组PBMC内HBV -DNA浓度及阳性率比较p <0 .0 1,存在显著差异 ;③血清HBV -DNA阴性而PBMCHBV -DNA阳性只有 1例 (1.7% ) ,其浓度为 1.5 0× 10 8/L .结论　①血清HBV -DNA浓度与PBMC内HBV -DNA的出现及HBV -DNA浓度存在明显相关性 .②临床上检测PMBC中HBV -DNA是对血清HBV -DNA的一个重要补充 ;③PBMC内HBV -DNA检测对观察病毒在非血清内的状态、间接反映肝细胞病毒复制情况以及进一步指导抗病毒治疗有一定意义     

抗NKG2D多克隆抗体抑制NK和LAK细胞细胞毒效应的研究

目的 :分析抗NKG2D多克隆抗体 ( pAb)对NK和LAK细胞毒作用的影响。方法 :应用密度梯度离心法分离外周血单个核细胞 (PBMC) ,经 10mg/LPHA和 1× 10 6U/LrhIL 2诱导LAK细胞产生 ,再应用流式细胞术 (FCM)分选NK细胞并进行表型检测。加入抗NKG2DpAb封闭NK和LAK细胞表面的NKG2D分子后 ,用MTT比色法检测其细胞毒效应。结果 :经FCM分析证实 ,获得高纯度、高活性的NK细胞。抗NKG2DpAb能显著抑制NK和LAK细胞对K5 6 2、HepG2细胞的细胞毒效应。NK细胞对两种靶细胞的细胞毒效应分别下降了 82 .9%和 75 .6 % ;LAK细胞对两种靶细胞的细胞毒效应分别下降了 5 2 .8%和 5 0 .2 %。但抗NKG2DpAb不能显著抑制两种效应细胞对人鼻咽癌细胞系CNE的细胞毒效应。结论 :抗NKG2DpAb可通过封闭NK和LAK细胞表面的NKG2D分子 ,抑制其对肿瘤细胞的细胞毒效应     

慢性乙型肝炎患者外周血Th17细胞/调节性T细胞比值变化的意义

目的测定慢性乙型肝炎(CHB)患者外周血CD4+CD25+Foxp3+调节性T细胞(Treg)和CD4+IL-17+T细胞(Th17细胞)频率及其相关细胞因子的变化,并探讨Th17/Treg平衡在CHB发病过程中的作用。方法选取CHB住院患者(CHB组)60例,其中35例轻中度CHB患者(CHB-LM),25例慢性重型肝炎患者(CSHB),同时选取21位健康体检者作为正常对照组(HC)。流式细胞术检测外周血中Th17和Treg的细胞频数,双抗体夹心ELISA检测血清中IL-17、IL-23、IL-10及转化生长因子β1(TGF-β1)的表达水平。结果与HC组相比,CHB患者外周血Th17细胞频率及其相关细胞因子IL-17、IL-23浓度明显增高,差异有统计学意义(P0.05);Treg频率及其相关细胞因子IL-10及TGF-β1浓度明显增高。Th17/Treg比值变化显示,与HC组相比,在CHB组中该比例明显升高,具有显著性差异,且与CHSB组相比,在CHB-LM组中该比值明显降低。结论 Th17细胞/Treg的失衡是造成慢性乙型肝炎病程演变的重要因素,检测Th17细胞/Treg比值变化对疾病发展的早期预测有一定价值。     

慢性乙型肝炎患者外周血T细胞KIR表达研究

目的：检测慢性乙型肝炎患者外周血T细胞表面KIR的表达情况。方法：采用三色流式细胞术检测慢性乙型肝炎患者外周血CD4^＋T细胞和CD8^high T细胞表面KIR分子表达，并与正常外周血比较。结果：慢性乙型肝炎患者外周血中CD8^high T细胞KIR表达明显高于对照组CD8^high T细胞。正常外周血CD4^＋T细胞几乎不表达KIR，慢性乙型肝炎患者外周血中CD4^＋T细胞表达KIR。结论：慢性乙型肝炎患者T细胞表面KIR表达明显增加。     

HIV原发感染者自然杀伤样T细胞NKG2A/NKG2D变化的研究

目的深入了解人类免疫缺陷病毒(human immunodeficiency virus,HIV)原发感染者(primary HIV infection,PHI)NKT样细胞表面NKG2A/NKG2D受体表达的变化。方法选取25例未经高效抗逆转录病毒治疗的HIV原发感染者和27例HIV抗体阴性健康对照,用流式细胞仪检测研究对象外周血NKT样细胞表面NKG2D和NKG2A的表达。结果 HIV原发感染者NKT样细胞绝对数和百分率显著低于健康对照(P<0.01)。HIV原发感染者NKT样细胞表面NKG2A、NKG2D受体表达与健康对照并无显著差异。HIV原发感染者病毒调定点低组NKG2A+NKT样细胞、NKG2A+NKG2D-NKT样细胞以及NKG2A+NKG2D+NKT样细胞百分率均显著低于病毒调定点高组(P<0.05);NKT细胞绝对数和百分率、NKG2D+NKT样细胞、NKG2D+NKG2A-NKT样细胞百分率在两组间相似,没有显著性差异。NKG2A+NKT细胞的百分比与病毒载量正相关(R=0.430,P=0.032)。结论 NKT样细胞数量以及其表面NKG2A受体的表达可作为HIV疾病进程的预测指标之一。     

Relations of regulatory T cells with hepatitis markers in chronic hepatitis B virus infection

To assess regulatory T cells (Treg) in chronic hepatitis B (CHB) infected patients and to evaluate the presence of a possible relation between them and hepatitis B markers, flow cytometry analysis was carried out to calculate the percentages of Tregs, Tregs secreting IL-10 and CD4(+) T cells secreting interferon-γ (IFN-γ) and enzyme-linked immunosorbent assay was used to detect hepatitis B virus (HBV) markers in 59 patients and 32 healthy controls. CD4(+)CD25(+), CD4(+)CD25(+)Foxp3(+), CD4(+)D25(high), CD4(+)CD25(high)Foxp3(+) and CD4(+)CD25(-)Foxp3(+) T cells and Treg cells secreting IL-10 were higher in CHB patients than in healthy controls. CD4(+)CD25(+), CD4(+)CD25(-), and total CD4(+)T cells secreting IFN-γ were generally lower in CHB patients than in healthy controls. Fair correlations were observed between CD4(+)CD25(+)Foxp3(+) T cells and alanine aminotransferase (ALT) levels and between HBsAb and both CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(high)Foxp3(+) T cells. CD4(+)CD25(+) T cells were significantly higher in CHB virus infected patients positive for HBeAg than in those negative for HBeAg and a good correlation was observed between CD4(+)CD25(+) T cells and HBeAg. Fair negative correlations were observed between CD4(+)CD25(high) T cells and both HBeAb and HBcAb. These data suggest that Tregs contribute to viral persistence. It was not possible to say that Tregs were the cause of immune suppression in this group of patients.     

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.     

CMV drives clonal expansion of NKG2C+ NK cells expressing self-specific KIRs in chronic hepatitis patients

Natural killer (NK) cells are affected by infection with human cytomegalovirus (HCMV) manifested by increased expression of the HLA-E binding activating receptor NKG2C. We here show that HCMV seropositivity was associated with a profound expansion of NKG2C(+) CD56(dim) NK cells in patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. Multi-color flow cytometry revealed that the expanded NKG2C(+) CD56(dim) NK cells displayed a highly differentiated phenotype, expressed high amounts of granzyme B and exhibited polyfunctional responses (CD107a, IFN-γ, and TNF-α) to stimulation with antibody-coated as well as HLA-E expressing target cells but not when stimulated with IL-12/IL-18. More importantly, NKG2C(+) CD56(dim) NK cells had a clonal expression pattern of inhibitory killer cell immunoglobulin-like receptors (KIRs) specific for self-HLA class I molecules, with predominant usage of KIR2DL2/3. KIR engagement dampened NKG2C-mediated activation suggesting that such biased expression of self-specific KIRs may preserve self-tolerance and limit immune-pathology during viral infection. Together, these findings shed new light on how the human NK-cell compartment adjusts to HCMV infection resulting in clonal expansion and differentiation of educated and polyfunctional NK cells.     

Association of NKG2A with treatment for chronic hepatitis C virus infection

Natural killer (NK) cells are critical to the immune response to viral infections. Their functions are controlled by receptors for major histocompatibility complex (MHC) class I, including NKG2A and killer‐cell immunoglobulin‐like receptors (KIR). In order to evaluate the role of MHC class I receptors in the immune response to hepatitis C virus infection we have studied patients with chronic HCV infection by multi‐parameter flow cytometry directly ex vivo. This has permitted evaluation of combinatorial expression of activating and inhibitory receptors on single NK cells. Individuals with chronic HCV infection had fewer CD56^dim NK cells than healthy controls (4·9 ± 3·4% versus 9·0 ± 5·9%, P < 0·05). Expression levels of the inhibitory receptor NKG2A was up‐regulated on NK cells from individuals with chronic hepatitis C virus (HCV) (NKG2A mean fluorescence intensity 5692 ± 2032 versus 4525 ± 1646, P < 0·05). Twelve individuals were treated with pegylated interferon and ribavirin. This resulted in a down‐regulation of NKG2A expression on CD56^dim NK cells. Individuals with a sustained virological response (SVR) had greater numbers of NKG2A‐positive, KIR‐negative NK cells than those without SVR (27·6 ± 9·6% NK cells versus 17·6 ± 5·7, P < 0·02). Our data show that NKG2A expression is dysregulated in chronic HCV infection and that NKG2A‐positive NK cells are associated with a beneficial response to pegylated interferon and ribavirin therapy.     

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.     

Phytohemagglutinin and concanavalin A activate hepatitis B virus in peripheral blood mononuclear cells of patients with chronic hepatitis B virus infection.

Peripheral blood mononuclear cells (PBMC) from 25 patients with chronic hepatitis B were tested for the presence of free monomeric hepatitis B virus (HBV) DNA migrating as a single 3.2 Kb band by Southern blot analysis. The PBMC were cultured for 7 days in the presence of phytohemagglutinin (PHA) or concanavalin A (ConA) both of which yielded a proliferative response. By contrast, both bacterial lipopolysaccharide (LPS) and interleukin 2 (IL2) failed to do so. Dot blot assays were used to monitor HBV DNA level increase within PBMC. Following mitogen exposure HBV DNA levels increased above pre-stimulation levels in 19/25 PHA cultures, 6/15 ConA cultures, 1/15 LPS cultures, and 1/15 IL2 cultures. In 15 patients, Southern blot analysis was carried out before and after PHA exposure. In 13/15 cases, a single 3.2 Kb band was observed in unstimulated cultures as well as in PHA cultures even though PHA induced a HBV DNA increase. One case exhibited bands migrating faster than the 3.2 Kb signal, compatible with replicating intermediates and one case provided evidence of viral concatemers within PBMC after PHA stimulation. No HBV DNA was detected in the culture supernatants. The increase of HBV DNA level in PBMC induced by mitogen was strongly associated with an increase in HBV DNA expression (HBV RNA and HBs antigen). These studies indicate that HBV DNA present in human PBMC does represent a potential reservoir for infection with endogenous reactivation following PBMC activation.     

Lack of correlation between interferon production of mononuclear cells and virus replication in chronic hepatitis B virus infection.

Interferon production in hepatitis B virus carriers with normal liver functions was preserved, whereas in carriers with chronic hepatitis it was depressed. The lower interferon production in hepatitis B virus carriers with chronic hepatitis appears to be the result rather than the cause of chronic hepatic disease.     

Clinical significance of occult hepatitis B virus infection in chronic hepatitis C patients

Background/Aims

We investigated the frequency of occult hepatitis B virus (HBV) infection in anti-hepatitis C virus (HCV)-positive individuals and the effects of occult HBV infection on the severity of liver disease.

Methods

Seventy-one hepatitis B virus surface-antigen (HBsAg)-negative patients were divided according to their HBV serological status into groups A (anti-HBc positive, anti-HBs negative; n=18), B (anti-HBc positive, anti-HBs positive; n=34), and C (anti-HBc negative, anti-HBs positive/negative; n=19), and by anti-HCV positivity (anti-HCV positive; n=32 vs. anti-HCV negative; n=39). Liver biopsy samples were taken, and HBV DNA was quantified by real-time PCR.

Results

Intrahepatic HBV DNA was detected in 32.4% (23/71) of the entire cohort, and HBV DNA levels were invariably low in the different groups. Occult HBV infection was detected more frequently in the anti-HBc-positive patients. Intrahepatic HBV DNA was detected in 28.1% (9/32) of the anti-HCV-positive and 35.9% (14/39) of the anti-HCV-negative subjects. The HCV genotype did not affect the detection rate of intrahepatic HBV DNA. In anti-HCV-positive cases, occult HBV infection did not affect liver disease severity.

Conclusions

Low levels of intrahepatic HBV DNA were detected frequently in both HBsAg-negative and anti-HCV-positive cases. However, the frequency of occult HBV infection was not affected by the presence of hepatitis C, and occult HBV infection did not have a significant effect on the disease severity of hepatitis C.     

Genotypes and clinical phenotypes of hepatitis B virus in patients with chronic hepatitis B virus infection

Genotype C of hepatitis B virus (HBV) has been shown to be associated with a poor clinical outcome, compared to genotype B. To explore the clinical phenotypes, with special reference to the seroconversion of hepatitis B e antigen (HBeAg) and frequency of acute exacerbation between patients infected with HBV genotypes B and C, a cohort of 272 Taiwanese patients with chronic HBV infection was analyzed. According to the status of HBeAg at enrollment and frequency of acute exacerbation during the follow-up period, five groups of patients with distinct clinical phenotypes were categorized. Of the 272 HBV carriers, 185 (68%) were infected with HBV genotype B and the remaining 87 (32%) were infected with genotype C. Among them, 150 (55%) were positive for HBeAg and patients with genotype C infection tended to have a higher positive rate of HBeAg than those with genotype B infection (63 versus 51%). Genotype B was more prevalent than genotype C in different groups of HBV carriers. However, the prevalence of genotype C in patients with multiple episodes of acute exacerbation who failed to have HBeAg seroconversion was significantly higher than in all 272 patients (50 versus 32%, P = 0.025), in those with HBeAg seroconversion after only one episode of acute exacerbation (50 versus 12%, P = 0.01), or in those negative for HBeAg at enrollment and without acute exacerbations (50 versus 23%, P = 0.002). In conclusion, patients with genotype C infection have a more aggressive clinical phenotype than do those with genotype B infection, which contributes to the former group's progressive liver disease and poor clinical outcomes.