AIM: To investigate a novel DNA vaccination based upon expression of the HBV e antigen fused to a heat shock protein (HSP) as a strategy to enhance DNA vaccine potency.METHODS: A pCMV-HBeAg-HSP DNA vaccine and a c...AIM: To investigate a novel DNA vaccination based upon expression of the HBV e antigen fused to a heat shock protein (HSP) as a strategy to enhance DNA vaccine potency.METHODS: A pCMV-HBeAg-HSP DNA vaccine and a control DNA vaccine were generated. Mice were immunized with these different construct. Immune responses were measured 2 wk after a second immunization by a T cell response assay, CTL cytotoxicity assay, and an antibody assay in C57BL/6 and BALB/c mice. CT26-HBeAg tumor cell challenge test in vivo was Performed in BALB/c mice to monitor anti-tumor immune responses.RESULTS: In the mice immunized with pCMV-HBe-HSP DNA, superior CTL activity to target HBV-positive target cells was observed in comparison with mice immunized with pCMV-HBeAg (44% ± 5% vs 30% ± 6% in E: T 〉 50:1, P 〈 0,05), ELISPOT assays showed a stronger T-cell response from mice immunized with pCMV-HBe- HSP than that from pCMV-HBeAg immunized animals when stimulated either with MHC class I or class Ⅱ epitopes derived from HBeAg (74% ± 9% vs 31% ± 6%, P 〈 0.01). ELISA assays revealed an enhanced HBeAg antibody response from mice immunized with pCMV- HBe-HSP than from those immunized with pCMV-HBeAg. The lowest tumor incidence and the slowest tumor growth were observed in mice immunized with pCMV- HBe-HSP when challenged with CT26-HBeAg.CONCLUSION: The results of this study demonstrate a broad enhancement of antigen-specific CD4^+ helper,CD8^+ cytotoxic T-cell, and B-cell responses by a novel DNA vaccination strategy. They also proved a stronger antigen-specific immune memory, which may be superior to currently described HBV DNA vaccination strategies for the treatment of chronic HBV infection.展开更多
Abstract [Objective] The paper was to prepare and detect the extended DNA fibers of Chinese cabbage. [Method] Chinese cabbage nuclei was first successfully isolated by chopping young leaves with a blade, then nuclei w...Abstract [Objective] The paper was to prepare and detect the extended DNA fibers of Chinese cabbage. [Method] Chinese cabbage nuclei was first successfully isolated by chopping young leaves with a blade, then nuclei were lysed by SDS to release DNA, and DNA fibers were dragged and extended with a coverslip. [Result] The results of Fiber-FISH with genomic DNA and 25S rDNA as probes showed that DNA fiber size as long as about 1.93 Mb could be measured and the number of 25S rDNA copies region were estimated to be 258 and 687 in Chinese cabbage genome. DNA fibers prepared by this method showed equally spread parallel thread with clear background, and were suitable for FISH analysis. [Conclusion] The study would accelerate Chinese cabbage genome mapping and organization analysis.展开更多
Objective:To investigate the effect of interleukin-18 (IL-18) on immune response induced by plasmid encoding hepatitis B virus middle protein antigen and to explore new strategies for prophylactic and therapeutic HBV ...Objective:To investigate the effect of interleukin-18 (IL-18) on immune response induced by plasmid encoding hepatitis B virus middle protein antigen and to explore new strategies for prophylactic and therapeutic HBV DNA vaccines.Methods:BALB/c mice were immunized with pCMV-M alone or co-immunized with pcDNA3-18 and pCMV-M and then their sera were collected for analysing anti-HBsAg antibody by ELISA;splenocytes were isolated for detecting specific CTL response and cytokine assay in vitro.Results:The anti-HBs antibody level of mice co-immunized with pcDNA3-18 and pCMV-M was slightly higher than that of mice immunized with pCMV-M alone,but there was not significantly different (P>0.05).Compared with mice injected with pCMV-M, the specific CTL cytotoxity activity of mice immunized with pcDNA3-18 and pCMV-M was significantly enhanced (P<0.05) and the level of IFN-γ in supernatant of splenocytes cultured with HBsAg in vitro was significantly elevated (P<0.05) while the level of IL-4 had no significant difference (P>0.05).Conclusion:The plasmid encoding IL-18 together with HBV M gene DNA vaccines may enhance specific TH1 cells and CTL cellular immune response induced in mice, so that IL-18 is a promising immune adjuvant.展开更多
The partitioning-defective 3 (Par3), a key component in the conserved Par3/Par6/aPKC complex, plays fundamental roles in cell polarity. Herein we report the identification of Ku70 and Ku80 as novel Par3-interacting ...The partitioning-defective 3 (Par3), a key component in the conserved Par3/Par6/aPKC complex, plays fundamental roles in cell polarity. Herein we report the identification of Ku70 and Ku80 as novel Par3-interacting proteins through an in vitro binding assay followed by liquid chromatography-tandem mass spectrometry. Ku70/Ku80 proteins are two key regulatory subunits of the DNA-dependent protein kinase (DNA-PK), which plays an essential role in repairing double-strand DNA breaks (DSBs). We determined that the nuclear association of Par3 with Ku70/Ku80 was enhanced by γ-irradiation (IR), a potent DSB inducer. Furthermore, DNA-PKcs, the catalytic subunit of DNA-PK, interacted with the Par3/Ku70/Ku80 complex in response to IR. Par3 over-expression or knockdown was capable of up- or downregulating DNA-PK activity, respectively. Moreover, the Par3 knockdown cells were found to be defective in random plasmid integration, defective in DSB repair following IR, and radiosensitive, phenotypes similar to that of Ku70 knockdown cells. These findings identify Par3 as a novel component of the DNA-PK complex and implicate an unexpected link of cell polarity to DSB repair.展开更多
As for many other tumors,development of hepatocellular carcinoma(HCC)must be understood as a multistep process with accumulation of genetic and epigenetic alterations in regulatory genes,leading to activation of oncog...As for many other tumors,development of hepatocellular carcinoma(HCC)must be understood as a multistep process with accumulation of genetic and epigenetic alterations in regulatory genes,leading to activation of oncogenes and inactivation or loss of tumor suppressor genes(TSG).In the last decades,in addition to genetic alterations,epigenetic inactivation of(tumor suppressor) genes by promoter hypermet hylation has been recognized as an important and alternative mechanism in tumorigenesis.In HCC,aberrant methylation of promoter sequences occurs not only in advanced tumors, it has been also observed in premalignant conditions just as chronic viral hepatitis B or C and cirrhotic liver. This review discusses the epigenetic alterations in hepatocellular carcinoma focusing DNA methylation.展开更多
Hepatitis C virus (HCV) chronic infection is a worldwide health problem, and numerous efforts have been invested to develop novel vaccines. An efficient vaccine requires broad immune response induction against viral p...Hepatitis C virus (HCV) chronic infection is a worldwide health problem, and numerous efforts have been invested to develop novel vaccines. An efficient vaccine requires broad immune response induction against viral proteins. To achieve this goal, we constructed a DNA vaccine expressing nonstructural 3 (NS3) gene (pcDNA3.1-HCV-NS3) and assessed the immune response in C57BL/6 mice. In this study, the NS3 gene was amplified with a nested-reverse transcriptase-polymerase chain reaction (RT-PCR) method using sera of HCV-infected patients with genotype 1a. The resulting NS3 gene was subcloned into a pcDNA3.1 eukaryotic expression vector, and gene expression was detected by western blot. The resultant DNA vaccine was co-administered with interleukin-12 (IL-12) as an adjuvant to female C57BL/6 mice. After the final immunizations, lymphocyte proliferation, cytotoxicity, and cytokine levels were assessed to measure immune responses. Our data suggest that co-administration of HCV NS3 DNA vaccine with IL-12 induces production of significant levels of both IL-4 and interferon (IFN)-γ (p<0.05). Cytotoxicity and lymphocyte proliferation responses of vaccinated mice were significantly increased compared to control (p<0.05). Collectively, our results demonstrated that co-administration of HCV NS3 and IL-12 displayed strong immunogenicity in a murine model.展开更多
Cancer cells differ from normal cells in various parameters, and these differences are caused by genomic mutations and consequential altered gene expression. The genetic and functional heterogeneity of tumor cells is ...Cancer cells differ from normal cells in various parameters, and these differences are caused by genomic mutations and consequential altered gene expression. The genetic and functional heterogeneity of tumor cells is a major challenge in cancer research, detection, and effective treatment. As such, the use of diagnostic methods is important to reveal this heterogeneity at the single-cell level. Droplet microfluidic devices are effective tools that provide exceptional sensitivity for analyzing single cells and molecules. In this review, we highlight two novel methods that employ droplet microfluidics for ultrasensitive detection of nucleic acids and protein markers in cancer cells. We also discuss the future practical applications of these methods.展开更多
Objective: To investigate the effect of interleukin-12 (IL-12) and interleukin-18 (IL-18)DNA immunization on immune response induced by HIV-1 DNA vaccine and to explore new strategies for therapeutic HIV DNA vaccine. ...Objective: To investigate the effect of interleukin-12 (IL-12) and interleukin-18 (IL-18)DNA immunization on immune response induced by HIV-1 DNA vaccine and to explore new strategies for therapeutic HIV DNA vaccine. Methods: The recombinant expression vector pCI-neoGAG was constructed by inserting HIV Gag gene into the eukaryotic expression vector pCI-neo. Balb/c mice were immunized with pCI-neoGAG alone or co-immunized with the DNA encoding for IL-12 or IL-18.Anti-HIV antibody and IFN-γ were tested by ELISA,and splenocytes were isolated for detecting antigen-specific lymphoproliferative responses and specific CTL response by MTT assay and LDH assay respectively. Results: The anti-HIV antibody titers of mice co-immunized with pCI-neoGAG and the DNA encoding for IL-12 or IL-18 were lower than that of mice immunized with pCI-neoGAG alone(P<0.01). In contrast, the IFN-γ level of mice co-immunized with pCI-neoGAG and the DNA encoding for IL-12 or IL-18 was higher than that of mice immunized with pCI-neoGAG alone (P<0.01).Furthermore, compared with mice injected with pCI-neoGAG alone, the specific CTL cytotoxity activity and antigen-specific lymphoproliferative responses of mice immunized with pCI-neoGAG and the DNA encoding for IL-12 or IL-18 were significantly enhanced respectively (P<0.01). Conclusion: The DNA encoding for IL-12 or IL-18 together with HIV DNA vaccine may enhance specific Th-1 responses and cellular immune response elicited in mice. Hence, the DNA encoding for IL-12 or IL-18 are promising immune adjuvants for HIV-1 DNA vaccine.展开更多
Human cytomegalovirus virions contain three major glycoprotein complexes (gC I, II, III), all of which are required for CMV infectivity. These complexes also represent major antigenic targets for anti-viral immune res...Human cytomegalovirus virions contain three major glycoprotein complexes (gC I, II, III), all of which are required for CMV infectivity. These complexes also represent major antigenic targets for anti-viral immune responses. The gC II complex consists of two glycoproteins, gM and gN. In the current study, DNA vaccines expressing the murine cytomegalovirus (MCMV) homologs of the gM and gN proteins were evaluated for protection against lethal MCMV infection in a mouse model. Humoral and cellular immune responses, spleen viral titers, and mice survival and body-weight changes were examined. The results showed that immunization with gM or gN DNA vaccine alone was not able to offer good protection, whereas co-immunization with both gM and gN induced an effective neutralizing antibody response and cellular immune response, and provided mice with complete protection against a lethal MCMV challenge. This study provides the first in vivo evidence that the gC II (gM-gN) complex may be able to serve as a protective subunit antigen for future HCMV vaccine development.展开更多
AIM:To investigate the mechanisms involved in a possible modulator role of interleukin(IL) -6 signalling on CYR61-CTGF-NOV(CCN) 2/connective tissue growth factor(CTGF) expression in hepatocytes(PC) and to look for a r...AIM:To investigate the mechanisms involved in a possible modulator role of interleukin(IL) -6 signalling on CYR61-CTGF-NOV(CCN) 2/connective tissue growth factor(CTGF) expression in hepatocytes(PC) and to look for a relation between serum concentrations of these two parameters in patients with acute inflammation. METHODS:Expression of CCN2/CTGF,p-STAT3,p-Smad 3/1 and p-Smad2 was examined in primary freshly isolated rat or cryo-preserved human PC exposed to various stimuli by Western blotting,electrophoretic mobility shift assay(EMSA) ,reporter-gene-assays and reversetranscriptase polymerase chain reaction. RESULTS:IL-6 strongly down-regulated CCN2/CTGF protein and mRNA expression in PC,enhanceable by extracellular presence of the soluble IL-6 receptor gp80,and supported by an inverse relation between IL-6 and CCN2/CTGF concentrations in patients'sera.The inhi-bition of TGFβ1 driven CCN2/CTGF expression by IL-6 did not involve a modulation of Smad2(and Smad1/3) signalling.However,the STAT3 SH2 domain binding peptide,a selective inhibitor of STAT3 DNA binding activity,counteracted the inhibitory effect of IL-6 on CCN2/CTGF expression much more pronounced than pyrrolidine-dithiocarbamate,an inhibitor primarily of STAT3 phosphorylation.An EMSA confirmed STAT3 binding to the proposed proximal STAT binding site in the CCN2/CTGF promoter. CONCLUSION:CCN2/CTGF is identified as a hepatocellular negative acute phase protein which is downregulated by IL-6 via the STAT3 pathway through interaction on the DNA binding level.展开更多
Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone...Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone deacetylase inhibitor (HDACi) trichostatin A (TSA) or DNA methylation inhibitor 5-Aza-C before detecting SATB1 expression. Luciferase reporter system was applied to measure effects of EZH2 on SATB1 promoter activity. Over-expression or knockdown of EZH2 and subsequent quantitative reverse transcription-polymerase chain reaction were performed to determine the effect of this Polycomb group protein on SATB1 transcription. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of EZH2 and trimethylated H3K27 (H3K27me3) at SATB1 promoter in HeLa cells. K562 cells and Jurkat cells, both having high-level expression of SATB1, were used in the ChIP experiment as controls. Results Both TSA and 5-Aza-C increased SATB1 expression in HeLa cells. Over-expression of EZH2 reduced promoter activity as well as the mRNA level of SATB1, while knockdown of EZH2 apparently enhanced SATB1 expression in HeLa cells but not in K562 cells and Jurkat cells. ChIP assay results suggested that epigenetic silencing of SATB1 by EZH2 in HeLa cells was mediated by trimethylation modification of H3K27. In contrast, enrichment of EZH2 and H3K27me3 was not detected within proximal promoter region of SATB1 in either K562 or Jurkat cells. Conclusion SATB1 is a bona fide EZH2 target gene in HeLa cells and the repression of SATB1 by EZH2 may be mediated by trimethylation modification on H3K27.展开更多
Objective: We studied the effects of Wortmannin (WM) on the proliferation and apoptosis of leukemia cells, and explore the possible mechanisms. Methods: The human myeloid leukemia cell line K562 was treated with d...Objective: We studied the effects of Wortmannin (WM) on the proliferation and apoptosis of leukemia cells, and explore the possible mechanisms. Methods: The human myeloid leukemia cell line K562 was treated with different concentrations of WM, and then detected the activity of the cell proliferation by MTT assay, comet tail formation of cell DNA damage phenomenon by single cell gel electrophoresis, cell apoptosis byAnnexin V-FITC/PI double staining and the expression levels of total Akt, phoshorylated Akt, NF-KB and protein in K562 cell by Western blotting, RT-PCR test before and after WM. Results: WM inhibited cell proliferation of K562 in a concentration-dependent manner, with IC50 value for 24 h being 25 nmol/L. WM induced apoptosis of K562 cells in a concentration-dependent manner, and could induce the breakage of DNA strand of K562 cell. The rate of DNA tail and the tail length of experimental groups were significantly higher than that of control group. WM may inhibit the expression of phosphorylated Akt and NF-KB protein in a dose-dependent manner in both the protein and gene levels, but no significant effect on total Akt protein. Conclusion: WM inhibited cell proliferation and induced apoptosis in K562 and concentration-dependent manner. The possible mechanism may be involved in the regulation of survival signaling pathway, such as PI3K/Akt/NK-KB.展开更多
Objective: The aim of this study was to determine whether the presence of IL-18 polymorphisms -137 G/C and -607 A/C was associated with grade, clinical stage, and survival in patients with prostate cancer. Methods: Th...Objective: The aim of this study was to determine whether the presence of IL-18 polymorphisms -137 G/C and -607 A/C was associated with grade, clinical stage, and survival in patients with prostate cancer. Methods: The study cohort included 126 patients with prostate cancer. Control group consisted of 125 samples from Chinese population. Genomic DNA was extracted from EDTA-anticoagulated peripheral blood leukocytes by the salting-out method. The genotyping of the two IL-18 polymorphisms was performed using predesigned TaqMan SNP Genotyping Assays. Results: The studied IL-18 gene polymorphisms did not influence susceptibility to prostate cancer in the analyzed group of patients (IL-18-607, P = 0.342; IL-18-137 P = 0.715) but may contribute to disease onset and aggressiveness. IL-18-607 CC genotype was significantly associated with higher tumor grade (P = 0.025) and stage (P = 0.001). IL-18-137 GG genotype was correlated with higher tumor grade (P = 0.018) and stage (P = 0.007). The Cox proportional hazard model showed that tuumor grade and stage grouping were independent prognostic factors but IL-18 polymorphism was not. Polymorphism variants in the IL-18 gene (IL-18-607 and IL-18-137) may be associated with a worse prognosis for prostate cancer. Conclusion: High levels of IL-18 production may play a major role in the growth, invasion and metastasis of prostate cancer.展开更多
Lymphotoxin(LT) is a glycoprotein secreted by activated T cell. The expression of LT gene is mainly regulated at the level of transcription. By using human LT DNA as a probe, we carried out a RNA dot blotting test and...Lymphotoxin(LT) is a glycoprotein secreted by activated T cell. The expression of LT gene is mainly regulated at the level of transcription. By using human LT DNA as a probe, we carried out a RNA dot blotting test and found that the longer the time of Jurkat human Tlymphoma cells exposed to the PMA and PHA, the more endogenous LT mRNA could be produced. Results of gel retardation assay showed that the nuclear extract from Jurkat cells treated with PMA and PHA formed different DNA-protein complexes. Changes in complex patterns were observed at various time intervals of PMA and PHA induction. A specific protein-binding site was mapped out to be a 22-bp sequence at the 5’upstream regioll of human LT gene by DNase I footprinting analysis. This region was similar to the sequence recognized by the proteins of NFkB family The results of fragment competition and homology analysis indicated that the 22-bp sequence contains a kB-like motif only which is located at the base pairs -100 to -90 (5’-GGGGGCTTCCC-3’). Thus, the NF-kBlike factors were involved in the protein-DNA interaction.Furthermore, there were more than one retarded bands appearing in the gel retardation assay. It suggested that there may be several NF-kB-like factors involved in theregulation of LT gene transcription at the same site.展开更多
Osteoarthritis(OA)is a degenerative articular disorder manifested by cartilage destruction,subchondral sclerosis,osteophytes,and synovitis,resulting in chronic joint pain and physical disability in the elderly.The pur...Osteoarthritis(OA)is a degenerative articular disorder manifested by cartilage destruction,subchondral sclerosis,osteophytes,and synovitis,resulting in chronic joint pain and physical disability in the elderly.The purpose of this study was to investigate mitochondrial DNA copy number(mtDNACN)and inflammatory cytokines in primary knee OA patients and healthy volunteers.A total of 204 knee OA patients and 169 age-matched healthy volunteers were recruited.Their relative blood leukocyte mtDNACN was assessed by quantitative real-time polymerase chain reaction(qRT-PCR),and ten inflammatory cytokines in their plasma were detected by multiplex immunoassay.Blood leukocyte mtDNACN in the OA group was significantly lower than that in the control group.Leukocyte mtDNACN in the control group was negatively correlated with their age(r=−0.380,P<0.0001),whereas mtDNACN in the OA group was positively correlated with their age(r=0.198,P<0.001).Plasma interleukin-4(IL-4)and IL-6 were significantly higher in the knee OA group than in the control group.The plasma IL-6 level was positively correlated with blood leukocyte mtDNACN in the OA group(r=0.547,P=0.0014).IL-5 showed as a major factor(coefficient 0.69)in the second dimension of principle components analysis(PCA)-transformed data and was significantly higher in the OA group(P<0.001)as well as negatively correlated with mtDNACN(r=−0.577,P<0.001).These findings suggest that elevation of plasma IL-4 and IL-6 and a relative reduction in mtDNACN might be effective biomarkers for knee OA.IL-5 is a plausible factor responsible for decreasing blood leukocyte mtDNACN in knee OA patients.展开更多
This study assessed and compared the immunogenicity of various immunization strategies in mice using combinations of re- combinant DNA (pCCMp24) and recombinant attenuated vaccinia virus Tian Tan (rddVTT_ccMpe4). ...This study assessed and compared the immunogenicity of various immunization strategies in mice using combinations of re- combinant DNA (pCCMp24) and recombinant attenuated vaccinia virus Tian Tan (rddVTT_ccMpe4). Intramuscular immuniza- tion was performed on days 0 (prime) and 21 (boost). The immunogenicity of the vaccine schedules was determined by meas- uring human immunodeficiency virus (HIV)-specific binding antibody levels and cytokine (interleukin-2 and interleukin-4) concentrations in peripheral blood, analyzing lymphocyte proliferation capacity against HIV epitopes and CD4~/CD8+cell ratio, and monitoring interferon-gamma levels at different times post-immunization. The results showed that pCCMp24, rddVTT.ccMp24 and their prime-boost immunization induced humoral and cellular immune responses. The pCCMp24/ rddVTT.ccMp24 immunization strategy increased CD8+ T cells and induced more IFN-7-secreting cells compared with sin- gle-shot rDNA. The prime-boost immunization strategy also induced the generation of cellular immunological memory to HIV epitope peptides. These results demonstrated that prime-boost immunization with rDNA and rddVTT_ccMp24 had a tendency to induce greater cellular immune response than single-shot vaccinations, especially IFN-7 response, providing a basis for further studies.展开更多
DNA is constantly exposed to a wide array of genotoxic agents, generating a variety of forms of DNA damage. DNA-protein crosslinks(DPCs)—the covalent linkage of proteins with a DNA strand—are one of the most deleter...DNA is constantly exposed to a wide array of genotoxic agents, generating a variety of forms of DNA damage. DNA-protein crosslinks(DPCs)—the covalent linkage of proteins with a DNA strand—are one of the most deleterious and understudied forms of DNA damage, posing as steric blockades to transcription and replication. If not properly repaired, these lesions can lead to mutations, genomic instability, and cell death. DPCs can be induced endogenously or through environmental carcinogens and chemotherapeutic agents. Endogenously, DPCs are commonly derived through reactions with aldehydes, as well as through trapping of various enzymatic intermediates onto the DNA. Proteolytic cleavage of the protein moiety of a DPC is a general strategy for removing the lesion. This can be accomplished through a DPC-specific protease and and/or proteasome-mediated degradation.Nucleotide excision repair and homologous recombination are each involved in repairing DPCs, with their respective roles likely dependent on the nature and size of the adduct. The Fanconi anemia pathway may also have a role in processing DPC repair intermediates. In this review, we discuss how these lesions are formed, strategies and mechanisms for their removal, and diseases associated with defective DPC repair.展开更多
文摘AIM: To investigate a novel DNA vaccination based upon expression of the HBV e antigen fused to a heat shock protein (HSP) as a strategy to enhance DNA vaccine potency.METHODS: A pCMV-HBeAg-HSP DNA vaccine and a control DNA vaccine were generated. Mice were immunized with these different construct. Immune responses were measured 2 wk after a second immunization by a T cell response assay, CTL cytotoxicity assay, and an antibody assay in C57BL/6 and BALB/c mice. CT26-HBeAg tumor cell challenge test in vivo was Performed in BALB/c mice to monitor anti-tumor immune responses.RESULTS: In the mice immunized with pCMV-HBe-HSP DNA, superior CTL activity to target HBV-positive target cells was observed in comparison with mice immunized with pCMV-HBeAg (44% ± 5% vs 30% ± 6% in E: T 〉 50:1, P 〈 0,05), ELISPOT assays showed a stronger T-cell response from mice immunized with pCMV-HBe- HSP than that from pCMV-HBeAg immunized animals when stimulated either with MHC class I or class Ⅱ epitopes derived from HBeAg (74% ± 9% vs 31% ± 6%, P 〈 0.01). ELISA assays revealed an enhanced HBeAg antibody response from mice immunized with pCMV- HBe-HSP than from those immunized with pCMV-HBeAg. The lowest tumor incidence and the slowest tumor growth were observed in mice immunized with pCMV- HBe-HSP when challenged with CT26-HBeAg.CONCLUSION: The results of this study demonstrate a broad enhancement of antigen-specific CD4^+ helper,CD8^+ cytotoxic T-cell, and B-cell responses by a novel DNA vaccination strategy. They also proved a stronger antigen-specific immune memory, which may be superior to currently described HBV DNA vaccination strategies for the treatment of chronic HBV infection.
基金Supported by National Natural Science Foundation of China (30471182)Youth Science Foundation of Hebei Province (C2010000738)~~
文摘Abstract [Objective] The paper was to prepare and detect the extended DNA fibers of Chinese cabbage. [Method] Chinese cabbage nuclei was first successfully isolated by chopping young leaves with a blade, then nuclei were lysed by SDS to release DNA, and DNA fibers were dragged and extended with a coverslip. [Result] The results of Fiber-FISH with genomic DNA and 25S rDNA as probes showed that DNA fiber size as long as about 1.93 Mb could be measured and the number of 25S rDNA copies region were estimated to be 258 and 687 in Chinese cabbage genome. DNA fibers prepared by this method showed equally spread parallel thread with clear background, and were suitable for FISH analysis. [Conclusion] The study would accelerate Chinese cabbage genome mapping and organization analysis.
文摘Objective:To investigate the effect of interleukin-18 (IL-18) on immune response induced by plasmid encoding hepatitis B virus middle protein antigen and to explore new strategies for prophylactic and therapeutic HBV DNA vaccines.Methods:BALB/c mice were immunized with pCMV-M alone or co-immunized with pcDNA3-18 and pCMV-M and then their sera were collected for analysing anti-HBsAg antibody by ELISA;splenocytes were isolated for detecting specific CTL response and cytokine assay in vitro.Results:The anti-HBs antibody level of mice co-immunized with pcDNA3-18 and pCMV-M was slightly higher than that of mice immunized with pCMV-M alone,but there was not significantly different (P>0.05).Compared with mice injected with pCMV-M, the specific CTL cytotoxity activity of mice immunized with pcDNA3-18 and pCMV-M was significantly enhanced (P<0.05) and the level of IFN-γ in supernatant of splenocytes cultured with HBsAg in vitro was significantly elevated (P<0.05) while the level of IL-4 had no significant difference (P>0.05).Conclusion:The plasmid encoding IL-18 together with HBV M gene DNA vaccines may enhance specific TH1 cells and CTL cellular immune response induced in mice, so that IL-18 is a promising immune adjuvant.
基金This work was supported by the grants from National Natural Science Foundation of China(Nos.30170208,30623003 and 30170208)from the Ministry of Science and Technology,China(No.2001AA233031 and No.2001CB510205)from US NIH(CA50519)(to DJ Chen).
文摘The partitioning-defective 3 (Par3), a key component in the conserved Par3/Par6/aPKC complex, plays fundamental roles in cell polarity. Herein we report the identification of Ku70 and Ku80 as novel Par3-interacting proteins through an in vitro binding assay followed by liquid chromatography-tandem mass spectrometry. Ku70/Ku80 proteins are two key regulatory subunits of the DNA-dependent protein kinase (DNA-PK), which plays an essential role in repairing double-strand DNA breaks (DSBs). We determined that the nuclear association of Par3 with Ku70/Ku80 was enhanced by γ-irradiation (IR), a potent DSB inducer. Furthermore, DNA-PKcs, the catalytic subunit of DNA-PK, interacted with the Par3/Ku70/Ku80 complex in response to IR. Par3 over-expression or knockdown was capable of up- or downregulating DNA-PK activity, respectively. Moreover, the Par3 knockdown cells were found to be defective in random plasmid integration, defective in DSB repair following IR, and radiosensitive, phenotypes similar to that of Ku70 knockdown cells. These findings identify Par3 as a novel component of the DNA-PK complex and implicate an unexpected link of cell polarity to DSB repair.
文摘As for many other tumors,development of hepatocellular carcinoma(HCC)must be understood as a multistep process with accumulation of genetic and epigenetic alterations in regulatory genes,leading to activation of oncogenes and inactivation or loss of tumor suppressor genes(TSG).In the last decades,in addition to genetic alterations,epigenetic inactivation of(tumor suppressor) genes by promoter hypermet hylation has been recognized as an important and alternative mechanism in tumorigenesis.In HCC,aberrant methylation of promoter sequences occurs not only in advanced tumors, it has been also observed in premalignant conditions just as chronic viral hepatitis B or C and cirrhotic liver. This review discusses the epigenetic alterations in hepatocellular carcinoma focusing DNA methylation.
文摘Hepatitis C virus (HCV) chronic infection is a worldwide health problem, and numerous efforts have been invested to develop novel vaccines. An efficient vaccine requires broad immune response induction against viral proteins. To achieve this goal, we constructed a DNA vaccine expressing nonstructural 3 (NS3) gene (pcDNA3.1-HCV-NS3) and assessed the immune response in C57BL/6 mice. In this study, the NS3 gene was amplified with a nested-reverse transcriptase-polymerase chain reaction (RT-PCR) method using sera of HCV-infected patients with genotype 1a. The resulting NS3 gene was subcloned into a pcDNA3.1 eukaryotic expression vector, and gene expression was detected by western blot. The resultant DNA vaccine was co-administered with interleukin-12 (IL-12) as an adjuvant to female C57BL/6 mice. After the final immunizations, lymphocyte proliferation, cytotoxicity, and cytokine levels were assessed to measure immune responses. Our data suggest that co-administration of HCV NS3 DNA vaccine with IL-12 induces production of significant levels of both IL-4 and interferon (IFN)-γ (p<0.05). Cytotoxicity and lymphocyte proliferation responses of vaccinated mice were significantly increased compared to control (p<0.05). Collectively, our results demonstrated that co-administration of HCV NS3 and IL-12 displayed strong immunogenicity in a murine model.
基金supported by a grant from the National Institutes of Health (Grant No. NIH/NGRR 1R21RR025371–01 to IS)
文摘Cancer cells differ from normal cells in various parameters, and these differences are caused by genomic mutations and consequential altered gene expression. The genetic and functional heterogeneity of tumor cells is a major challenge in cancer research, detection, and effective treatment. As such, the use of diagnostic methods is important to reveal this heterogeneity at the single-cell level. Droplet microfluidic devices are effective tools that provide exceptional sensitivity for analyzing single cells and molecules. In this review, we highlight two novel methods that employ droplet microfluidics for ultrasensitive detection of nucleic acids and protein markers in cancer cells. We also discuss the future practical applications of these methods.
文摘Objective: To investigate the effect of interleukin-12 (IL-12) and interleukin-18 (IL-18)DNA immunization on immune response induced by HIV-1 DNA vaccine and to explore new strategies for therapeutic HIV DNA vaccine. Methods: The recombinant expression vector pCI-neoGAG was constructed by inserting HIV Gag gene into the eukaryotic expression vector pCI-neo. Balb/c mice were immunized with pCI-neoGAG alone or co-immunized with the DNA encoding for IL-12 or IL-18.Anti-HIV antibody and IFN-γ were tested by ELISA,and splenocytes were isolated for detecting antigen-specific lymphoproliferative responses and specific CTL response by MTT assay and LDH assay respectively. Results: The anti-HIV antibody titers of mice co-immunized with pCI-neoGAG and the DNA encoding for IL-12 or IL-18 were lower than that of mice immunized with pCI-neoGAG alone(P<0.01). In contrast, the IFN-γ level of mice co-immunized with pCI-neoGAG and the DNA encoding for IL-12 or IL-18 was higher than that of mice immunized with pCI-neoGAG alone (P<0.01).Furthermore, compared with mice injected with pCI-neoGAG alone, the specific CTL cytotoxity activity and antigen-specific lymphoproliferative responses of mice immunized with pCI-neoGAG and the DNA encoding for IL-12 or IL-18 were significantly enhanced respectively (P<0.01). Conclusion: The DNA encoding for IL-12 or IL-18 together with HIV DNA vaccine may enhance specific Th-1 responses and cellular immune response elicited in mice. Hence, the DNA encoding for IL-12 or IL-18 are promising immune adjuvants for HIV-1 DNA vaccine.
基金supported by the Innovation Platform Open Fund of Hunan Provincial Education Department (11K010)a research fund from Hunan Provincial Science and Technology Development (2008TP4033-2)
文摘Human cytomegalovirus virions contain three major glycoprotein complexes (gC I, II, III), all of which are required for CMV infectivity. These complexes also represent major antigenic targets for anti-viral immune responses. The gC II complex consists of two glycoproteins, gM and gN. In the current study, DNA vaccines expressing the murine cytomegalovirus (MCMV) homologs of the gM and gN proteins were evaluated for protection against lethal MCMV infection in a mouse model. Humoral and cellular immune responses, spleen viral titers, and mice survival and body-weight changes were examined. The results showed that immunization with gM or gN DNA vaccine alone was not able to offer good protection, whereas co-immunization with both gM and gN induced an effective neutralizing antibody response and cellular immune response, and provided mice with complete protection against a lethal MCMV challenge. This study provides the first in vivo evidence that the gC II (gM-gN) complex may be able to serve as a protective subunit antigen for future HCMV vaccine development.
文摘AIM:To investigate the mechanisms involved in a possible modulator role of interleukin(IL) -6 signalling on CYR61-CTGF-NOV(CCN) 2/connective tissue growth factor(CTGF) expression in hepatocytes(PC) and to look for a relation between serum concentrations of these two parameters in patients with acute inflammation. METHODS:Expression of CCN2/CTGF,p-STAT3,p-Smad 3/1 and p-Smad2 was examined in primary freshly isolated rat or cryo-preserved human PC exposed to various stimuli by Western blotting,electrophoretic mobility shift assay(EMSA) ,reporter-gene-assays and reversetranscriptase polymerase chain reaction. RESULTS:IL-6 strongly down-regulated CCN2/CTGF protein and mRNA expression in PC,enhanceable by extracellular presence of the soluble IL-6 receptor gp80,and supported by an inverse relation between IL-6 and CCN2/CTGF concentrations in patients'sera.The inhi-bition of TGFβ1 driven CCN2/CTGF expression by IL-6 did not involve a modulation of Smad2(and Smad1/3) signalling.However,the STAT3 SH2 domain binding peptide,a selective inhibitor of STAT3 DNA binding activity,counteracted the inhibitory effect of IL-6 on CCN2/CTGF expression much more pronounced than pyrrolidine-dithiocarbamate,an inhibitor primarily of STAT3 phosphorylation.An EMSA confirmed STAT3 binding to the proposed proximal STAT binding site in the CCN2/CTGF promoter. CONCLUSION:CCN2/CTGF is identified as a hepatocellular negative acute phase protein which is downregulated by IL-6 via the STAT3 pathway through interaction on the DNA binding level.
基金Supported by National Natural Science Foundation of China (30721063)National Basic Research Program of China (973 Program) (2005CB522402, 2006CB910403)+1 种基金National Laboratory of Medical Molecular Biology grant (2060204)Beijing municipal government grant (YB20081002301)
文摘Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone deacetylase inhibitor (HDACi) trichostatin A (TSA) or DNA methylation inhibitor 5-Aza-C before detecting SATB1 expression. Luciferase reporter system was applied to measure effects of EZH2 on SATB1 promoter activity. Over-expression or knockdown of EZH2 and subsequent quantitative reverse transcription-polymerase chain reaction were performed to determine the effect of this Polycomb group protein on SATB1 transcription. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of EZH2 and trimethylated H3K27 (H3K27me3) at SATB1 promoter in HeLa cells. K562 cells and Jurkat cells, both having high-level expression of SATB1, were used in the ChIP experiment as controls. Results Both TSA and 5-Aza-C increased SATB1 expression in HeLa cells. Over-expression of EZH2 reduced promoter activity as well as the mRNA level of SATB1, while knockdown of EZH2 apparently enhanced SATB1 expression in HeLa cells but not in K562 cells and Jurkat cells. ChIP assay results suggested that epigenetic silencing of SATB1 by EZH2 in HeLa cells was mediated by trimethylation modification of H3K27. In contrast, enrichment of EZH2 and H3K27me3 was not detected within proximal promoter region of SATB1 in either K562 or Jurkat cells. Conclusion SATB1 is a bona fide EZH2 target gene in HeLa cells and the repression of SATB1 by EZH2 may be mediated by trimethylation modification on H3K27.
基金Supported by a grant from the Hubei Province Natural Science Foundation of China(No. 200511008)
文摘Objective: We studied the effects of Wortmannin (WM) on the proliferation and apoptosis of leukemia cells, and explore the possible mechanisms. Methods: The human myeloid leukemia cell line K562 was treated with different concentrations of WM, and then detected the activity of the cell proliferation by MTT assay, comet tail formation of cell DNA damage phenomenon by single cell gel electrophoresis, cell apoptosis byAnnexin V-FITC/PI double staining and the expression levels of total Akt, phoshorylated Akt, NF-KB and protein in K562 cell by Western blotting, RT-PCR test before and after WM. Results: WM inhibited cell proliferation of K562 in a concentration-dependent manner, with IC50 value for 24 h being 25 nmol/L. WM induced apoptosis of K562 cells in a concentration-dependent manner, and could induce the breakage of DNA strand of K562 cell. The rate of DNA tail and the tail length of experimental groups were significantly higher than that of control group. WM may inhibit the expression of phosphorylated Akt and NF-KB protein in a dose-dependent manner in both the protein and gene levels, but no significant effect on total Akt protein. Conclusion: WM inhibited cell proliferation and induced apoptosis in K562 and concentration-dependent manner. The possible mechanism may be involved in the regulation of survival signaling pathway, such as PI3K/Akt/NK-KB.
文摘Objective: The aim of this study was to determine whether the presence of IL-18 polymorphisms -137 G/C and -607 A/C was associated with grade, clinical stage, and survival in patients with prostate cancer. Methods: The study cohort included 126 patients with prostate cancer. Control group consisted of 125 samples from Chinese population. Genomic DNA was extracted from EDTA-anticoagulated peripheral blood leukocytes by the salting-out method. The genotyping of the two IL-18 polymorphisms was performed using predesigned TaqMan SNP Genotyping Assays. Results: The studied IL-18 gene polymorphisms did not influence susceptibility to prostate cancer in the analyzed group of patients (IL-18-607, P = 0.342; IL-18-137 P = 0.715) but may contribute to disease onset and aggressiveness. IL-18-607 CC genotype was significantly associated with higher tumor grade (P = 0.025) and stage (P = 0.001). IL-18-137 GG genotype was correlated with higher tumor grade (P = 0.018) and stage (P = 0.007). The Cox proportional hazard model showed that tuumor grade and stage grouping were independent prognostic factors but IL-18 polymorphism was not. Polymorphism variants in the IL-18 gene (IL-18-607 and IL-18-137) may be associated with a worse prognosis for prostate cancer. Conclusion: High levels of IL-18 production may play a major role in the growth, invasion and metastasis of prostate cancer.
文摘Lymphotoxin(LT) is a glycoprotein secreted by activated T cell. The expression of LT gene is mainly regulated at the level of transcription. By using human LT DNA as a probe, we carried out a RNA dot blotting test and found that the longer the time of Jurkat human Tlymphoma cells exposed to the PMA and PHA, the more endogenous LT mRNA could be produced. Results of gel retardation assay showed that the nuclear extract from Jurkat cells treated with PMA and PHA formed different DNA-protein complexes. Changes in complex patterns were observed at various time intervals of PMA and PHA induction. A specific protein-binding site was mapped out to be a 22-bp sequence at the 5’upstream regioll of human LT gene by DNase I footprinting analysis. This region was similar to the sequence recognized by the proteins of NFkB family The results of fragment competition and homology analysis indicated that the 22-bp sequence contains a kB-like motif only which is located at the base pairs -100 to -90 (5’-GGGGGCTTCCC-3’). Thus, the NF-kBlike factors were involved in the protein-DNA interaction.Furthermore, there were more than one retarded bands appearing in the gel retardation assay. It suggested that there may be several NF-kB-like factors involved in theregulation of LT gene transcription at the same site.
基金Project supported by the 90th Anniversary of Chulalongkorn University(No.RA61/104)the Research Chair Grant from the National Science and Technology Development Agency+1 种基金the 100th Anniversary of Chulalongkorn University Fund for Doctoral Scholarshipthe Overseas Research Experience Scholarship for Graduate Student,Thailand and China Scholarship Council,China
文摘Osteoarthritis(OA)is a degenerative articular disorder manifested by cartilage destruction,subchondral sclerosis,osteophytes,and synovitis,resulting in chronic joint pain and physical disability in the elderly.The purpose of this study was to investigate mitochondrial DNA copy number(mtDNACN)and inflammatory cytokines in primary knee OA patients and healthy volunteers.A total of 204 knee OA patients and 169 age-matched healthy volunteers were recruited.Their relative blood leukocyte mtDNACN was assessed by quantitative real-time polymerase chain reaction(qRT-PCR),and ten inflammatory cytokines in their plasma were detected by multiplex immunoassay.Blood leukocyte mtDNACN in the OA group was significantly lower than that in the control group.Leukocyte mtDNACN in the control group was negatively correlated with their age(r=−0.380,P<0.0001),whereas mtDNACN in the OA group was positively correlated with their age(r=0.198,P<0.001).Plasma interleukin-4(IL-4)and IL-6 were significantly higher in the knee OA group than in the control group.The plasma IL-6 level was positively correlated with blood leukocyte mtDNACN in the OA group(r=0.547,P=0.0014).IL-5 showed as a major factor(coefficient 0.69)in the second dimension of principle components analysis(PCA)-transformed data and was significantly higher in the OA group(P<0.001)as well as negatively correlated with mtDNACN(r=−0.577,P<0.001).These findings suggest that elevation of plasma IL-4 and IL-6 and a relative reduction in mtDNACN might be effective biomarkers for knee OA.IL-5 is a plausible factor responsible for decreasing blood leukocyte mtDNACN in knee OA patients.
基金supported by the National Natural Science Foundation of China (81001342)the National Basic Research Program of China (2011CB512110)the National Mega Project on Major Infectious Diseases Prevention (2012ZX10001005-006)
文摘This study assessed and compared the immunogenicity of various immunization strategies in mice using combinations of re- combinant DNA (pCCMp24) and recombinant attenuated vaccinia virus Tian Tan (rddVTT_ccMpe4). Intramuscular immuniza- tion was performed on days 0 (prime) and 21 (boost). The immunogenicity of the vaccine schedules was determined by meas- uring human immunodeficiency virus (HIV)-specific binding antibody levels and cytokine (interleukin-2 and interleukin-4) concentrations in peripheral blood, analyzing lymphocyte proliferation capacity against HIV epitopes and CD4~/CD8+cell ratio, and monitoring interferon-gamma levels at different times post-immunization. The results showed that pCCMp24, rddVTT.ccMp24 and their prime-boost immunization induced humoral and cellular immune responses. The pCCMp24/ rddVTT.ccMp24 immunization strategy increased CD8+ T cells and induced more IFN-7-secreting cells compared with sin- gle-shot rDNA. The prime-boost immunization strategy also induced the generation of cellular immunological memory to HIV epitope peptides. These results demonstrated that prime-boost immunization with rDNA and rddVTT_ccMp24 had a tendency to induce greater cellular immune response than single-shot vaccinations, especially IFN-7 response, providing a basis for further studies.
基金supported by the National Institutes of Health (CA179441, CA193124-Project 3 to Lei Li)
文摘DNA is constantly exposed to a wide array of genotoxic agents, generating a variety of forms of DNA damage. DNA-protein crosslinks(DPCs)—the covalent linkage of proteins with a DNA strand—are one of the most deleterious and understudied forms of DNA damage, posing as steric blockades to transcription and replication. If not properly repaired, these lesions can lead to mutations, genomic instability, and cell death. DPCs can be induced endogenously or through environmental carcinogens and chemotherapeutic agents. Endogenously, DPCs are commonly derived through reactions with aldehydes, as well as through trapping of various enzymatic intermediates onto the DNA. Proteolytic cleavage of the protein moiety of a DPC is a general strategy for removing the lesion. This can be accomplished through a DPC-specific protease and and/or proteasome-mediated degradation.Nucleotide excision repair and homologous recombination are each involved in repairing DPCs, with their respective roles likely dependent on the nature and size of the adduct. The Fanconi anemia pathway may also have a role in processing DPC repair intermediates. In this review, we discuss how these lesions are formed, strategies and mechanisms for their removal, and diseases associated with defective DPC repair.