Establishment of an ELISA to Detect Kaposi's Sarcoma-associated Herpesvirus Using Recombinant ORF73

Kaposi's sarcoma-associated herpesvirus (KSHV) is causally related to Kaposi's sarcoma (KS), primary effusion lymphoma (PEL) and a proportion of cases of multicentric Castleman's disease (MCD). The ORF73 protein was cloned into pQE80L-orf73 and expressed in E.coli and purified. The expressed recombinant ORF73 was identified by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). A protein of about 27 kDa was expressed as expected. Western Blotting showed that the purified recombinant ORF73 reacted with KSHV positive serum. The immunogenicity of the recombinant ORF73 was further analysed by ELISA and the optimal conditions were determined. The ORF73 ELISA was used to compare the KSHV seroprevalence between Hubei and Xinjiang Han people. The Han people in Xinjiang have significantly higher KSHV seroprevalence than their counterparts in Hubei (6.7% vs 2.9%, P = 0.005).

Immunogenicity Analysis of Prokaryotic Expression Products of Kaposi's Sarcoma Associated Herpesvirus orf65

To purify the protein encoding the small capsid protein （SCP） of KSHV and analyze its immunogenicity, the carboxyl terminus of orf65 of Kaposi＇s sarcoma associated-herpesvirus （KSHV） was expressed in a prokaryotic expression system. The expression of recombinant E.coli containing pQE-80L-orf65 was induced by isopropyl-13-D-thiogalactopyranoside （IPTG） and the fusion protein was purified by chromatography. The expressed protein and its purified product were identified by sodium dodecyl sulfate- polyacrylamide gel electrophoresis （SDS-PAGE） and showed that 9 kDa was the expected size of the purified orf65 protein. The antiserum was produced in rabbit which was immunized by purified orf65 protein. An ELISA assay was established to analyze the immunogenicity of the purified orf65 protein. The ELISA analysis demonstrated that orf65 protein has strong immune activity, and the immune activity of polyclonal antibody against orf65 was more than 4 fold higher than that in the serum of the non-immunized rabbit. These results demonstrate that purified orf65 protein has very strong immunogenicity and can be used in screening KSHV infection in the general population using ELISA.

Expression of Kaposi's Sarcoma-associated Herpesvirus ORFK8.1 and Its Preliminary Diagnostic Application

The ORFK8.1 of Kaposi＇s sarcoma associated-herpesvirus （KSHV） was expressed in a prokaryotic expression system. The expression of recombinant E.coli containing pQE-80L-orf KS.1 was induced by isopropyl-b-D-thiogalactopyranoside （IPTG）. The fusion protein was purified by chromatyography. The expressed protein and its purified product were identified by sodium dodecyl sulfate-polyacrylamide gel eletrophoresis （SDS-PAGE）. SDS-PAGE showed that a protein of 26 kDa was visualized as expected. A western blot assay was established to analyze the immunogenicity of purified recombinant ORFKS. 1 protein. The optimal condition of the recombinant ORFKS. 1 ELISA assay was confirmed： the concentration of antigen was 5 μg/mL, the dilution of serum was 1：200. We used the ELISA method to investigate the recombinant ORF KS. 1 protein＇s specificity, the data showed that the specificity of ORF KS.1 to detect KSHV was 100%. At the same time, 560 sera samples from Hubei province were detected by using ORFKS. 1 ELISA to investigate KSHV seroprevalence in this region. The KSHV seroprevalence in Hubei province is shown to be 6.80%.

Pathogenesis and Associated Diseases of Kaposi's Sarcoma-associated Herpesvirus

Kaposi's sarcoma-associated herpesvirus(KSHV)is the primary etiological agent of Kaposi's sarcoma,primary effusion lymphoma and muticentric Castleman's disease.In common with the other herpesviruses,KSHV exhibits both latent and lytic life cycles,both of which are characterized by distinct gene expression profiles and programs.KSHV encodes proteins which play essential roles in the inhibition of host adaptive and innate immunity,the inhibition of apoptosis,and the regulation of the cell cycle.KSHV also encodes several proteins which have transforming and intrcellular signalling activity.

Angiogenesis,Kaposi’s Sarcoma and Kaposi’s Sarcoma-associated Herpesvirus

Tumor angiogenesis is the uncontrolled growth of blood vessels in tumors,serving to supply nutrients and oxygen,and remove metabolic wastes. Kaposi’s sarcoma (KS),a multifocal angioproliferative disorder characterized by spindle cell proliferation,neo-angiogenesis,inflammation,and edema,is associated with infection by Kaposi's sarcoma-associated herpesvirus (KSHV). Recent studies indicate that KSHV infection directly promotes angiogenesis and inflammation through an autocrine and paracrine mechanism by inducing pro-angiogenic and pro-inflammatory cytokines. Many of these cytokines are also expressed in KS lesions,implicating a direct role of KSHV in the pathogenesis of this malignancy. Several KSHV genes are involved in KSHV-induced angiogenesis. These studies have provided insights into the pathogenesis of KS,and identified potential therapeutic targets for this malignancy.

Genotypic analysis on the ORF-K1 gene of human herpesvirus 8 from patients with Kaposi's sarcoma in Xinjiang,China

Human herpesvirus 8 （HHV-8） is thought to be essential for the development of all forms of Kaposi＇s sarcoma （KS）. HHV-8 DNA is present virtually in all KS tumor biopsy samples. Genes at both ends of the HHV-8 genome have been shown to vary considerably. Seven major molecular subtypes of HHV-8 were defined based on the amino acid sequence of the open reading frame K1 （ORF-K1）, generally known as A, B, C, D, E, F, and Z. Most strains collected worldwide were clustered into two subtypes （A and C）. Here, the K1/VRI region of HHV-8 was amplified by nested PCR in 22 （81.48%） of 27 cases from Xinjiang Uygur Autonomous Region, a province in northwestern China. Phylogenetic analysis on the basis of the K1/VR1 amino acid sequence indicated that the majority of these KS patients were infected by subtype C HHV-8 （n = 18, including 15 belonging to the C2 group）, and several by subtype A （n = 4, including 3 being the A1 group）. This is the first report of subtype A HHV-8 in China. Furthermore, the correlations between different forms and lesions of KS and different subtypes of HHV-8 were analyzed. The findings showed that subtype A HHV-8 resulted in significantly more frequent mucosal KS lesions than subtype C. However, there was no obvious correlation between different forms of KS and different subtypes of HHV-8.

The Role of Human Herpesvirus 8 Molecular Characterization in the Management of HIV Infected Patients Diagnosed with Malignancies Associated with Its Infection

Despite the progress has been reached with Human herpesvirus 8 (HHV-8) research, there are gaps in the knowledge of viral induced oncogenesis. The aim of the present study was to identify possible associations between HHV-8 subtypes, HHV-8 loads and clinical manifestations of HIV infected patients diagnosed with different malignancies associated with HHV-8 infection. Forty six HIV-1 infected individuals diagnosed with different HHV-8 associated diseases were studied [37 epidemic Kaposi’s sarcoma (KS), 3 pleural effusion lymphoma (PEL);5 peripheral lymphadenopathies (PL);1 Hodgkin’s lymphoma (HL);1 non Hodgkin’s lymphoma (NHL)]. HHV-8 loads were determined by quantitative real time PCR (qRT-PCR) whilst HHV-8 subtypes were determined by open-reading frame (ORF)-K1 gen genotyping. HHV-8 subtypes B, A, C, A5 and E were exhibited by 31.8%, 23.4%, 19.1%, 17% and 8.5% of the studied patients, respectively. The median HHV-8 viral load did not differ between subtypes (p > 0.05) but HHV-8 viral loads were significantly higher in PEL than in epidemic KS lesion or lymph nodes (p = 0.04). Subtype B was detected in 60% of patients with B cell lymphoma (NHL, PEL and HL) whereas subtype E was only detected in patients with epidemic KS diagnosis. Our data suggest that HHV-8 DNA quantification instead of subtype identification could be used as a surrogate marker for monitoring its infection, not only in epidemic KS patients but also in HIV infected individuals with lymphoproliferative disorders.

Prevention and Treatment of KSHV-associated Diseases with Antiviral Drugs

Kaposi’s sarcoma-associated herpesvirus (KSHV) was first identified as the etiologic agent of Kaposi’s sarcoma (KS) in 1994. KSHV infection is necessary,but not sufficient for the development of Kaposi sarcoma (KS),primary effusion lymphoma (PEL),and multicentric Castleman disease (MCD). Advances in the prevention and treatment of KSHV-associated Diseases have been achieved,even though current treatment options are ineffective,or toxic to many affected persons. The identification of new targets for potential future therapies and the randomized trial to evaluate the efficacy of new antivirals are required.

维吾尔族Kaposi’s肉瘤患者组织中KSHV-vFLIP表达水平与患者临床特征相关性

目的探讨维吾尔族卡波西肉瘤(Kaposi’s sarcoma,KS)患者皮损组织内KSHV-vFLIP基因表达水平与临床特征的相关性。方法选取29例维吾尔族卡波西肉瘤患者和12例血管瘤(hemangioma)患者、11例健康对照患者皮损石蜡包埋组织,反转录-聚合酶链反应(RT-PCR)分析KSHV-vFLIP基因mRNA表达水平。结果 KS患者KSHV-vFLIP基因表达水平(4.436±0.508)显著高于健康对照组(1.145±0.112,P<0.05),其中斑块型组KSHV-vFLIP基因表达水平(8.104±2.225)显著高于结节型组(3.971±0.371,P<0.05)和斑片组(2.774±0.867,P<0.05)。而KS组(4.436±0.507)与血管瘤组(6.343±0.949)差异无统计学意义(P>0.05),且HIV携带组(3.739±0.816)与非HIV携带组(4.618±0.604)差异无统计学意义(P>0.05)。结论在维吾尔族卡波西肉瘤患者组织中,KSHV-vFLIP基因表达水平与瘤体体积正相关。

一种新的人类疱疹病毒:Kaposi’s肉瘤相关疱疹病毒(KSHV)

１９９４年Ｙ．Ｃｈａｎｇ等人从ＡＩＤＳ患者的Ｋａｐｏｓｉ’ｓ肉瘤（ＫＳ）组织中分离到了两种独有的序列［１］，并由ＫＳ建立了基因组文库，对其中外源序列进行克隆和序列分析［２］，初步确认一种新的人类疱疹病毒———ＫＳ相关疱疹病毒。１ＫＳＨＶ的发现Ｋａｐｏ...

AIDS and associated malignancies

AIDS associated malignancies （ARL） is a major complication associated with AIDS patients upon irnmunosuppression. Chronically immunocompromised patients have a markedly increased risk of developing lymphoproliferative disease. In the era of potent antiretrovirals therapy （ARV）, the malignant complications due to HIV-1 infection have decreased in developed nations where ARV is administered, but still poses a major problem in developing countries where HIV-1 incidence is high and ARV is still not yet widely available. Even in ARV treated individuals there is a concern that the prolonged survival of many HIV-1 carriers is likely to eventually result in an increased number of malignancies diagnosed. Malignancies that were found to have high incidence in HIV-infected individuals are Kaposi＇s sarcoma （KS）, Hodgkin＇s disease （HD） and non-Hodgkin＇s lymphoma （NHL）. The incidence of NHL has increased nearly 200 fold in HIV-positive patients, and accounts for a greater percentage of AIDS defining illness in the US and Europe since the advent of HAART therapy. These AIDS related lymphomas are distinct from their counterparts seen in HIV- 1 seronegative patients. For example nearly haft of all cases of ARL are associated with the presence of a gamma herpesvirus, Epstein Barr virus （EBV） or human herpesvirus-8 （HHV-8）/Kaposi＇s sarcoma associated herpesvirus （KSHV）. The pathogenesis of ARLs is complex. B-cell proliferation driven by chronic antigenemia resulting in the induction of polyclonal and ultimately monoclonal lymphoproliferation may occur in the setting of severe immunosuppression.

Regulation of Wnt/β-catenin signaling by herpesviruses

The Wnt/β-catenin signaling pathway is instrumental in successful differentiation and proliferation of mammalian cells. It is therefore not surprising that the herpesvirus family has developed mechanisms to interact with and manipulate this pathway. Successful coexistence with the host requires that herpesviruses establish a lifelong infection that includes periods of latency and reactivation or persistence. Many herpesviruses establish latency in progenitor cells and viral reactivation is linked to host-cell proliferation and differentiation status. Importantly, Wnt/β-catenin is tightly connected to stem/progenitor cell maintenance and differentiation. Numerous studies have linked Wnt/β-catenin signaling to a variety of cancers, emphasizing the importance of Wnt/β-catenin pathways in development, tissue homeostasis and disease. This review details how the alpha-, beta-, and gammaherpesviruses interact and manipulate the Wnt/β-catenin pathway to promote a virus-centric agenda.

Intestinal Kaposi's sarcoma may mimic gastrointestinal stromal tumor in HIV infection

Diffuse intestinal Kaposi＇s sarcoma shares macroscopic and histopathologic features with gastrointestinal stromal tumors. Correct diagnosis may pose a clinical challenge. We describe the case of a young HIV-1-infected African lady without advanced immunodeficiency, who presented with a diffuse spindle cell tumor of the gut. Initial diagnosis was of a gastrointestinal stromal tumor, based on endoscopy and histopathology. Further evaluation revealed evidence for human herpesvirus 8 （HHV8） and the diagnosis had to be changed to diffuse intestinal Kaposi＇s sarcoma. Antiretroviral triple therapy together with chemotherapy was commenced, and has led to the rapid remission of intestinal lesions. With a background of HIV infection, the presence of HHV8 as the causative agent of Kaposi＇s sarcoma should be determined, as distinct treatment is indicated.

Prevalence of Kaposi's sarcoma-associated herpesvirus in Uygur and Han populations from the Urumqi and Kashgar regions of Xinjiang, China

Kaposi's sarcoma-associated herpesvirus(KSHV) is the infectious etiologic agent associated with Kaposi's sarcoma(KS), primary effusion lymphoma, and multicentric Castleman disease. It has been shown that high KSHV prevalence and high incidence of both classic KS and AIDSassociated KS are found mostly among people of Uygur ethnicity in Xinjiang, while people of Han ethnicity in Xinjiang have a higher KSHV seroprevalence than those of other Han populations in China's Mainland. However, it is still unclear why there is such geographical and population variation in KSHV distribution in China. In this work, we focused on the populations in the Kashgar region and Urumqi area, where a total of 1294 research subjects were randomly selected to investigate the potential correlation between KSHV prevalence and different ethnicities in endemic areas of Xinjiang, and to determine risk factors that may affect KSHV infection rates or KS incidence. We identified a high seroprevalence of KSHV and high peripheral blood DNA infection in the general Uygur and Han populations in both Urumqi and Kashgar regions of Xinjiang, and determined that advancing age, low education level, and stationary population status affect KSHV infection rates. Further, KSHV-positive Uygur participants were shown to have higher prevalence of neutralizing antibodies and neutralizing antibody titers than KSHV-positive Han participants.

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.

KSHV ORF73C基因原核表达产物的纯化与免疫原性分析

目的 纯化卡波济肉瘤相关疱疹病毒 (KSHV)潜伏相关核抗原 (LANA)羧基端编码基因ORF73C原核表达蛋白并分析其免疫原性。方法 含重组质粒pGEX 6p 1+ORF73C(pORF73C)的宿主菌BL2 1经异丙基硫代 β D 半乳糖苷 (IPTG)诱导表达。用glutathioneSepharose 4B亲和层析柱纯化表达产物后 ,以重组 3C蛋白酶对融合蛋白进行解离 ,SDS PAGE对表达及纯化产物进行鉴定。以纯化的ORF73C蛋白免疫小鼠获得抗血清 ,建立ELISA检测其免疫原性。结果 SDS PAGE显示蛋白条带大小分别为 4 90 0 0和 2 30 0 0 ,与预期的ORF73C融合蛋白及ORF73C蛋白分子量大小一致 ;ELISA检测显示 ,抗ORF73C多抗免疫反应性高于未免疫小鼠血清 2倍以上。结论 成功获得了纯化的ORF73C蛋白 ,经ELISA显示其有较强免疫原性。

HHV6感染激活卡波济肉瘤相关疱疹病毒(KSHV)的溶解性周期复制

运用细胞融合、细胞混合培养、条件培养基培养和病毒直接刺激等方法,研究人类疱疹病毒6型(HHV6)对卡波济肉瘤相关疱疹病毒(KSHV)溶解性周期复制的影响。①将HHV6感染的JJhan细胞(T淋巴细胞系)与BCBL-1细胞(原发性渗出性淋巴瘤,PEL)进行细胞融合形成异核体细胞。②将HHV6感染的JJhan细胞与BCBL-1细胞进行混合培养。③收集HHV6感染的JJhan细胞培养上清液作为条件培养基进行灭活处理,以灭活前后的条件培养基培养BCBL-1细胞。进一步离心纯化HHV6病毒颗粒,并感染BCBL-1细胞,分别设紫外线和热灭活的HHV6病毒颗粒感染BCBL-1细胞为对照。提取上述的实验细胞总RNA,RT-PCR和/或实时定量(Real—time)PCR检测卡波济肉瘤相关疱疹病毒(KSHV)次要衣壳蛋白编码基因ORF26mRNA转录。结果显示:①细胞融合后15h开始出现明显细胞病变,RT-PCR检测不同时间的实验组ORF26mRNA转录水平均明显高于对照组;Real—timePCR检测各时间ORF26mRNA转录水平是对照组的2.3倍以上;②细胞混合培养72h时,实验组ORF26mRNA转录水平是对照组的1.8倍;混合培养5天时,实验组KSHV裂解周期蛋白K8.1表达水平是对照组的2.46倍;③灭活前后的HHV6感染细胞培养上清液培养BCBL-1细胞96h时,ORF26mRNA转录水平分别是对照组的2.73倍和2.22倍;④灭活前后的HHV6均可增强BCBL-1细胞中KSHVORF26mRNA转录水平。提示:HHV6感染可激活KSHV的溶解性周期复制。

KSHV K15P慢病毒载体的构建及其滴度测定

目的构建含卡波肉瘤相关疱疹病毒(KSHV)ORF K15P基因的慢病毒载体,并对其在293T细胞内的表达进行研究。方法 PCR法扩增获得KSHV K15P基因,限制性内切酶Nhe I酶切和无缝克隆法构建重组慢病毒载体p CDHCMV-K15P-GFP,通过脂质体转染试剂将重组慢病毒载体与3种辅助质粒p MDL-PRRE、pRSV-Rev和p MD2.g共转染HEK 293T细胞包装产生慢病毒,Western blot法检测K15P蛋白的表达。结果经酶切及测序鉴定,成功构建慢病毒载体,重组慢病毒质粒与辅助质粒共转染HEK 293T细胞可见有荧光表达,说明K15P基因在细胞内有表达并且96 h后产生4×106TU/ml滴度为慢病毒。结论成功构建了KSHV K15P慢病毒表达载体p CDH-CMV-K15P-GFP,获得高效表达K15P基因的慢病毒颗粒,为后续其在细胞内的功能研究奠定实验基础。

含KSHV vIL-6基因原核表达载体的构建及融合蛋白的表达纯化与鉴定

目的:在大肠埃希菌中表达卡波济肉瘤相关疱疹病毒(Kaposi′s sarcoma-associated herpesvirus,KSHV)vIL-6基因,并进一步纯化和鉴定表达蛋白。方法:以本实验室已构建的重组质粒pGEX-6p-1-vIL-6为模板,PCR扩增目的基因片段,将PCR产物克隆至原核表达载体pET-32a(+)中,构建vIL-6的重组原核表达质粒pET-32a(+)-vIL-6。将重组质粒转化大肠埃希菌(E.coli)BL21(DE3)感受态细胞,用异丙基硫代-β-D-半乳糖苷(IPTG)诱导表达融合蛋白。表达产物通过镍亲和层析柱纯化并经蛋白质印迹法鉴定。结果:限制性内切酶检测和基因测序证实,成功构建了含有vIL-6基因的原核表达载体。蛋白质印迹法结果显示,在大肠埃希菌BL21(DE3)中His-Tag融合蛋白得到了表达,亲和层析法纯化后获得了相对分子质量为43 000的vIL-6融合蛋白。结论:重组质粒pET-32a(+)-vIL-6能在大肠埃希菌BL21(DE3)中表达,利用镍亲和层析柱可纯化获得融合蛋白。

Kaposi肉瘤组织内人疱疹病毒8型的K14.1基因型研究

目的:确定人疱疹病毒8型K14.1基因等位基因型在Kaposi肉瘤中的分布,及与Kaposi肉瘤临床分型的关系。方法:使用酚-氯仿-异戊醇法对32例Kaposi肉瘤石蜡包埋组织进行病毒DNA提取,使用PCR法扩增K14.1基因片段,然后确定其等位基因型。结果:32例中有27例人疱疹病毒8型感染为阳性,阳性率为84.38%,其中5例艾滋病相关型KS患者HHV-8感染均为阳性,感染率100%;在分析的27例HHV-8病毒株中,24例为P等位基因型(包括5例艾滋病相关型KS患者皮损),3例为M等位基因型(均来自经典型KS)。结论:本研究中,Kaposi肉瘤感染的人疱疹病毒8型的K14.1等位基因型以P等位基因型为主。