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Objective: Using yeast surface presentation technology, secreted anti-PD-L1 single-chain antibody fragment ( sc Fv), then purify the sc Fv that specifically binds PD-L1 antigen. The sc Fv antibody gene sequence was synthesized based on the single chain antibody gene sequence. We express this sc Fv-mFc protein by using p Fuse eukaryotic expression vector to study its affinity and in vitro and in vivo inhibition of lung adenocarcinoma cells ( A549). Methods: Recombinant plasmid p Fuse-scFv was constructed by gene engineering. The recombinant plasmid p Fuse-scFv was transfected into 293 F ( human embryonic kidney cells) and cultured in serum-free Pro293 a-CDM for 72 hours, then the fusion protein was collected, and use the Rapid Protein Liquid Phase Separation and Purification System to purify the sc Fv-mFc fusion protein. Then the fusion protein and the tumor cells were detected by immunohistochemistry; the affinity of fusion protein and tumor cells was analyzed by flow cytometry; ADCC was used to determine the proliferation of tumor cells in vitro. The nude mice inoculated with lung adenocarcinoma cells, and use the fusion protein to verify its anti-tumor effect in vivo. Results: sc Fv-mFc fusion protein was secreted into serum-free culture medium by recombinant plasmid transfection into the 293 F cells; immunohistochemistry and flow cytometry showed that the fusion protein was highly expressed with the surface of PD-L1 protein;ADCC showed that the fusion protein inhibited the proliferation of tumor cells in vitro; the results of tumor-bearing mice showed that the fusion protein inhibited the growth of the tumor. At the dose of 5 mg/kg, The tumor volume growth rate decreased from 14. 90％ to3. 72％, the two independent samples t test P＜0. 05, the difference was statistically significant. Conclusion: The fusion protein containing single chain antibody was successfully prepared, which had good binding ability to A549 cells and inhibited the proliferation of tumor cells in vitro and in vivo, and provided the laboratory basis for the development of targeted anti-tumor drugs.
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Aim To construct different over-expression vectors of ST8Sial gene and establish a cell line with stable ST8Sial over-expression , and to check the proliferation of cells with ST8Sial over-expression. Methods Polymerase chain reaction ( PCR) was used to amplify the code region of ST8Sial. The amplified ST8Sial fragment and pEGFP-Cl vector, pHBLV-CMV-MCS-3flag-EFl-ZsGreen-T2A-Puro vector were digested with restriction enzymes. The target gene fragment and the different vectors were ligated to obtain the ST8Sial-pEGFP-Cl recombinant vector and the recombinant lentiviral vector, respectively. PCR and DNA sequencing were used to identify recombinant vectors. Melanoma cells WM451 were transfected with different vectors. Cell line with stable ST8Sial over-expressing was established. ST8Sial mRNA level was checked by real-time PCR. STSSial protein expression level was checked by Western blot. Proliferation of the stable cells was assayed by CCK-8 method. The clony formation of stable cells was also performed. Results Both ST8Sial-pEGFP-Cl recombinant plasmid and STSSial over-expression lentiviral vectors were successfully constructed. The transfection efficiency of ST8Sial over-expression lentiviral vector was much higher than that of ST8Sial-pEGFP-Cl recombinant plasmid. A WM451 cell line with stable ST8Sial over-expression lentiviral vectors was established. Results showed that the over-expression of ST8Sial promoted the proliferation and colony formation of cells. Conclusions ST8Sial over-expression vectors are successfully constructed. The over-expression of ST8Sial promotes the proliferation and colony formation of WM451 cells.
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@#Objective To detect the difference of periostin expression in small cell lung cancer (SCLC) cell, and explore its effect on chemoresistance of SCLC patients. Methods The expression of periostin in mRNA and protein was detected by RT-PCR and Western blot analysis in SCLC H69 and multidrug resistant strain H69AR. The expression of periostin was up-regulated by recombinant plasmid-periostin in H69 cell. The survival rate in the transfected group was different from that of the negative control group and uninterrupted group. Results The expression of periostin mRNA and protein in the sensitive strain H69 was lower than that of the multidrug resistant strain H69AR (P<0.05). The recombinant periostin-plasmid was transfected into H69 cells and at the same concentration of chemotherapeutic drugs (cisplatin, etoposide) the survival rate increased significantly (P<0.05). The positive expression rate of periostin in SCLC tissues was 67.44%, and the sensitivity of the chemotherapy group was lower than that of the drug resistant group (P<0.05). Conclusion The expression of periostin in SCLC cell H69 is significantly lower than that of the multidrug resistant strain H69AR and overexpression of periostin increases resistance of the sensitive strain H69 and hence periostin may be involved in SCLC chemoresistance.
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Objective To construct rat lysine-specific histone demethylase 1 (LSD1) overexpression plasmids and LSD 1 demethylation fragment disfunction plasmids,and to evaluate their expression levels in HEK293T cells.Methods LSD1 fragments were amplified by PCR,and LSD1 demethylation disfunction fragments were amplified by overlap PCR.Rat-specific LSD1 overexpression plasmids and LSD1 demethylation disfunction plasmids were constructed and verified by agarose gel electrophoresis and sequencing.HEK293T cells were infected using the validated recombinant plasmids and blank vectors,and the stably expressed cells were selected by puromycin.The expression of LSD1 in the stably expressed HEK293T was detected by Western Blot and real-time quantitative PCR.Results The results of agarose gel electrophoresis and sequencing showed that LSD1 overexpression plasmids and LSD1 demethylation disfunction plasmids were successfully constructed.The Western Blot and real-time quantitative PCR results showed that compared with the blank group,the relative expression of LSD1 and mRNA in the LSD1 overexpression group and the LSD1 demethylation disfunction group were up-regulated,and the differences were statistically significant(all P＜0.01).Conclusions The constructed LSD1 overexpression plasmids and LSD1 demethylationi disfunction plasmids can achieve overexpression of LSD1 gene in HEK293T cells.This paper lays a foundation for further study of the relationship between LSD 1 gene and related diseases and demethylation of LSD 1.
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Objective To obtain the prokaryotic expression of transketolase genes and analyze its value as a diagnostic anti-gen for echinococcosis.Methods TK gene was amplified by PCR and cloned into prokaryotic vector pMD19-EgTK,and then subcloned into the expression vector pET-28a.The target gene TK prokaryotic expression plasmid pET-28a was constructed and transferred into BL21. The purified protein was identified by SDS-PAGE and Western blotting. The blood samples of patients with cystic echinococcosis(CE group),alveolar echinococcosis(AE group)and healthy people(healthy group)were collected and detected by ELISA with the recombinant EgTK protein as a diagnostic antigen.Results The recombinant plasmid pET-28a (+)-EgTK was constructed successfully,and there was a band around 70 kDa by using Western blotting.ELISA showed that the difference among the 3 groups of sera reaction A450was significantly different(F=44.47,P<0.01),and the A450values of the CE group(1.46±0.41)and AE group(1.28±0.29)were higher than that of the healthy group(0.66 ± 0.23),but there was no significant difference between the former two.Conclusion The recombinant EgTK protein is better to distinguish the echinococ-cosis group and healthy group,but it can't do a differential diagnosis between CE and AE cases.
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Objective To explore the effect of the recombinant plasmid pcDNA3.1/C-sis on fulminant hepatic failure (FHF) in rats.Methods 48 h after recombinant plasmid pcDNA3.1/C-sis being imported into rat liver by using the method of fluid mechanics,FHF in rats was induced by endotoxin (LPS)+D-galactosamine (D-GaIN).With fluorescence quantitative PCR and Western blotting,C-sis expression was tested.The apoptosis of rat liver was detected by using HE staining and measuring Caspase-3 activity.The expression changes of Bcl-2 and Bax were examined through using Western blotting.The mortality rate of rats was calculated during 24 h observation period.Resnlts Compared with the normal control group and FHF+ empty plasmid group,C-sis mRNA and protein expression levels were increased significantly in the FHF+C-sis plasmid group,there were statistically significant differences (P＜0.01).Compared with the normal control group,the apoptotic hepatocytes were increased in the FHF + Ringer's solution injection group and FHF+ empty plasmid group;compared with FHF+ empty plasmid group,the apoptotic hepatocytes in the FHF+C-sis plasmid group were decreased.Compared with the normal control group,Caspase-3 expression level was increased in the FHF+ Ringer's solution injection group (P＜0.01);compared with the FHF+ empty plasmid group,Caspase-3 expression level in the FHF+C-sis plasmid group was decreased (P＜0.05).Compared with the normal control group,Bcl-2 expression level was decreased significantly (P＜0.01),and Bax expression level was increased significantly (P＜0.01) in the FHF+Ringer's solution injection group;compared with the FHF+ empty plasmid group,the Bcl-2 expression level was increased (P＜0.05),and Bax expression was decreased (P＜0.05)in the FHF+C-sis plasmid group.During the 24 h observation period,all rats in the normal control group were alive;the mortality rates of the FHF+ Ringer's solution injection group and FHF+ empty plasmid group were 70.0％ and 80.0％ respectively,while that of the FHF+C-sis plasmid group was only 20.0％.Conclusion C-sis gene could inhibit FHF in rats induced by LPS+D-GalN.
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Objective@#To study the construction and humoral immunogenicity of the recombinant plasmids encoding nonstructural proteins(NSs) of severe fever with thrombocytopenia syndrome(SFTS) virus(SFTSV).@*Methods@#Recombinant plasmids encoding NSs gene and optimized NSs gene of SFTSV were constructed by polymerase chain reaction(PCR) and cloned into eukaryotic expression vector pJW4303, which were named pJW4303-NSs and pJW4303-NSs-opt, respectively. Then, the plasmid pJW4303-NSs was tagged with Flag, named pJW4303-NSs-Flag. Meanwhile, Nhe I restrict site and tissue plasminogen activator(tPA) signal sequence were inserted to construct bi-optimized recombinant plasmid named pJW4303-tPA-NSs-opt. All plasmids were identified by sequencing. The transient expression of NSs was confirmed by Western blotting in human embryonic kidney 293T cells. The NSs-specific IgG antibodies in BALB/c mice which were immunized by intramuscular injection with electroporation were examined by enzyme-linked immunosorbent assay(ELISA).@*Results@#The recombinant plasmids pJW4303-NSs, pJW4303-NSs-opt, pJW4303-tPA-NSs-opt and pJW4303-NSs-Flag were successfully constructed. The expression of NSs was confirmed in lysates and supernatants of 293T cells. The NSs-specific IgG responses of all three recombinant plasmids were detected by ELISA in BALB/c mice. It was found that optimized recombinant plasmid pJW4303-NSs-opt elicited higher levels of the NSs-specific IgG than that of pJW4303-NSs in week 6, 8 which induced stronger immune response.@*Conclusions@#The recombinant plasmids encoding SFTSV NSs possess the satisfied immunogenicity. In addition, the plasmid pJW4303-NSs-opt could induce the strongest humoral immune response.
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Objective To construct the pEGFP-C1-CXCL1 eukaryotic expression vector and to investigate the effect of CXCL1 on the proliferation of HepG2 cells under endoplasmic reticulum stress ( ERS).Methods Fragments of CXCL1 were obtained from the cDNA library of HepG2 cells before CXCL1 was cloned into a pEGFP-C1 vector for a recombinant plasmid pEGFP-C1-CXCL1 which was screened and identified by PCR and sequence alignment .Then,the recombinant plas-mid of pEGFP-C1-CXCL1 was transfected into human 293 T cell line and the expression of CXCL 1 was detected by fluores-cence microscopy and Western blotting.pEGFP-C1-CXCL1was furhter transfected into HepG2 cells, and CCK8 was used to detect the inhibitory effect of CXCL1 on tumor proliferation induced by TM in hepatocellular carcinoma .Results pEGFP-C1-CXCL1 was vertified by sequencing analysis .Fluorescence microscopy showed that pEGFP-C1-CXCL1 was transfected into 293T.CXCL1 expression was detected by Western blotting .CCK8 showed that TM inhibited tumor proliferation , while overexpression of CXCL1 decreased the inhabitory rate on cell proliferation of HepG 2 cells under ER stress compared to pEGFP-C1 group and the control group .Conclusion A recombinant pEGFP-C1-CXCL1 plasmid is successfully constructed that can be expressed stably in human 293T cells.Overexpression of CXCL1 can effectively reduce the inhabitory rate of HCC cells induced by the ER stress.
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@#AIM: To construct a recombinant eukaryotic expression vector of rat beta defensin-2(rBD-2), transfect it into the rat corneal epithelial cells with lipofection, determine the expression of target gene in the transfected cells, and discuss the potentiality of recombinant plasmid expressed in corneal epithelial cells, hoping to provide an experimental foundation for further study on the antimicrobial activity of rBD-2 <i>in vitro </i>and <i>in vivo</i> and to assess the probability of defensins as a new application for infectious corneal diseases in the future. <p>METHODS: The synthetic rBD-2 DNA fragment was inserted between the <i>Xho</i>I and <i>BamHI</i> restriction enzyme cutting sites of eukaryotic expression vector pIRES2-ZsGreen1 to construct the recombinant plasmid pIRES2-ZsGreen1-rBD-2, then transformed it into <i>E.coli DH5α</i>, positive clones were screened by kanamycin and identified with restriction endonucleases and sequencing analysis. Transfection into the rat corneal epithelial cells was performed by lipofection. Then the experiment was divided into three groups: rat corneal epithelial cell was transfected with the recombinant plasmid pIRES2- ZsGreen1-rBD-2, rat corneal epithelial cell was transfected with the empty plasmid pIRES2-ZsGreen1 and the non-transfected group. The inverted fluorescence microscope was used to observe the transfection process. At last, the level of rBD-2 mRNA expressed in the transfected cells and the control groups are compared by the real-time fluoresence relative quantitative PCR. <p>RESULTS: The recombinant eukaryotic expression vector of pIRES2-ZsGreen1-rBD-2 was successfully constructed. The level of rBD-2 mRNA in transfected cells was significantly higher than that in control groups through the real-time fluorescence relative quantitative PCR. <p>CONCLUSION: The recombinant eukaryotic expression vector pIRES2-ZsGreen1-rBD-2 could be transfected into rat corneal epithelial cells, and exogenous rBD-2 gene could be transcripted into mRNA in the transfected cells.
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Objective To explore the effect and mechanism of fragile site WWOX gene on regulating proliferation of gallbladder cancer cells in vitro. Methods The pcDNA3.0 - WWOX recombinant plasmid which was previous successfully built was transfected to GBC-SD cells and empty carrier by liposome medium. Liposome and GBC-SD were served as the negative control and the blank control,respectively. After 48 hours transfection, inverted microscope was used to observe the changes of gallbladder cancer cells' morphology,MTT and BrdU were used to detect the proliferation level of gallbladder cancer cells,and flow cytometry instrument was used to detect the change of the cell proliferation cycle. Results The results of inverted microscope shown: the number of GBC-SD cells in pcDNA3.0-WWOX group decreased significantly,the suspension cells and cell debris increased,while cells in the vector control,NC and Mock groups were in normal proliferation state. MTT test showed the proliferation levels of GBC-SD cells in pcDNA3.0-WWOX group was lower than those in the control group in 24 h,48 h,72 h,96 h and 120 h,and the differences were statistically significant(P 0.05). Conclusion The overexpression of WWOX gene in vitro could effectively inhibit the proliferation activity of gallbladder cancer cells. WWOX might participate in the development of the malignant biological behavior of gallbladder cancer cells. It is expected to become a new potential target for the gene therapy to gallbladder cancer.
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Objective: To obtain the transgenic safflower plants which expressed Arabidopsis thaliana metallothionein 2 (MT2) gene, and lay a foundation for development of MT products. Methods: The oleosin-MT gene was obtained from pEASY-oleosin-MT by Nco I/Hind III, then was inserted into plant expression vector pOP. The recombinant plasmid named pOP-oleosin-MT was transferred into Agrobacterium tumefaciens EHA105.The oleosin-MT gene was introduced into safflowers via Agrobacterium-mediated method and positive transgenic plants were determined by PCR analysis. Results: The recombinant plasmid pOP-oleosin-MT was successfully constructed. PCR and Southern blotting analysis confirmed that MT gene was integrated into the genome of safflower plant and three transgenic plants were obtained. Conclusion: The safflower regeneration system is constructed successfully and MT gene is successfully transformed into safflower plant.
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Objective To construct the recombinant eukaryotic expression plasmids of human adenylyl cyclase-associated protein 1 (CAP1)and to explore its intracellular location and functions.Methods By using Hela cDNA as the template,the cDNAs encoding CAP1 was amplified by PCR and inserted into pCMV-Myc vector to construct the recombinant plasmid.The recombinant plasmid was transfected into 293 cells using lipofectamine 2000.The protein expression and the intracellular location of the inserted gene were confirmed by Western blotting and immunofluorescence,respectively.Scratch-repair experiment was used to detect the cancer cells’ migration ability.Results The recombinant eukaryotic expression plasmid of human CAP1 was successfully constructed and transfected into eukaryote cells.The recombinant plasmid was successfully expressed in eukaryote cells.CAP1 was located in the cytoplasm.The results of scratch-repair experiment showed that the overexpression of CAP1 could significantly inhibit the cells’ migration.Conclusion CAP1 recombinant plasmid was successfully expressed in eukaryotic cells.CAP1 protein was located in the cytoplasm.The overexpression of CAP1 inhibited cell migration. The present study provides important experimental evidence for further study on CAP1.
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Objective To construct pEGFP-N1-TGF-β1 recombinant plasmid and transfect it into primary cultured neonatal piglet type Ⅱ alveolar epithelium cell (AEC-Ⅱ) by using lipofectamine 2000,in order to provide basis of methodology for producing recombinant plasmids for transplantation of transfected AEC-Ⅱ into ALI/ARDS animal model lungs.Methods PCR primers were designed to amplify the human TGF-β1 cDNA fragment from plasmid.XhoI and EcoRI were used for double digesting the empty plasmid pEGFP-N1 and cDNA fragment of human TGF-β1.Then the products of double enzyme digestion by using T4 DNA ligase were connected and transformed into DH5α and cultured over night for 16 hours.The structure of recombinant plasmid was identified by using PCR and base sequencing to verify the correctness of pEGFP-N1-TGF-β1 recombinant plasmid.It was then transfected into primarily cultured AEC-Ⅱ by lipofectamine2000 mediated transfection and cultured for another 48 hour.Plasmid DNA (pEGFP-N1-TGF-β1 recombinant plasmid) and lipofectamine 2000 were added into serum-free DMEM respectively,then DNA suspension and Lipofectamine 2000 suspension were blended together and added into cells.After 24-48 hours later,the expression level of enhanced green fluorescent protein (EGFP) was evaluated under fluorescence microscope.Results The structure of vector was verified as pEGFP-N1-TGF-β1 recombinant plasmid by using PCR and base sequencing.Green fluorescence found in some cells showed that the pEGFP-N1-TGF-β1 recombinant plasmids had been successfully transfected into primary cultured AEC-Ⅱ,however,the transfection efficiency still need tobe further improved such as repeating the transfection procedure once again or using adenovirus mediated transfection method to improve the efficiceny and to transplant the cells into animal lungs eventually.Conclusions pEGFP-N1-TGF-β1 recombinant plasmid was successfully constructed and,for the first time,transfected into primarily cultured AEC-Ⅱ of newborn piglets.This established method should be useful for investigation of therapeutic effect and outcomes of lung with experimental acute lung injury.
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AIM: To verify the role of enhancing or suppressing the expression of glutathione peroxidase 1 (GPx1) in the growth, migration and invasion of glioblastoma multiforme cell lines U87MG and U118MG.METHODS:U87MG and U118MG cell lines were transfected with the vector containing specific siRNA or pcDNA3.1 recombinant plas-mid both targeting GPx1.The mRNA and protein expression levels of GPx1 were detected by real-time PCR and Western blotting.MTS assay was applied for determining the cell activity.The abilities of migration and invasion were examined by Transwell assay.RESULTS:Compared with blank control group and negative group, the inhibitory rate of the cell activity in U87MG cells in siRNA group was significantly reduced by 25.9%, 35.7%and 34.8%at 24 h, 48 h and 72 h, respec-tively (P<0.05).In contrast, the cell activity of U118MG cells in pcDNA3.1-GPx1 group was significantly increased by 22.7%, 45.8%and 39.8%at 24 h, 48 h and 72 h, respectively ( P<0.05) .In siRNA group, the inhibitory rate of mi-gration in U87MG cells was 41.6%±8.2%and the invasion was 41.6%±8.2%compared with blank control group and negative group (P<0.05).The cell migration and invasion rates of the U118MG cells in pcDNA-GPx1 group were in-creased by 55.8%±9.8% and 60.8% ±9.2%, respectively, compared with blank control group and negative group (P<0.05).CONCLUSION:The down-regulation of GPx1 by specific siRNA reduces the capability of cell growth, mi-gration and invasion of U87MG cells, while up-regulation of GPx1 by pcDNA3.1-GPx1 increases the capability of cell growth, migration and invasion of U118MG cells.
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Objective:To construct and screen the high efficiency interference plasmid of TFAIP8-shRNA-pSIREN-RetroQ.Methods:Selected and synthesized three Target Sequence of TNFAIP8 shRNA1,TNFAIP8 shRNA2,TNFAIP8 shRNA3,and construct the TNFAIP8 interference plasmid.Transfection TNFAIP8-shRNA-pSIREN-RetroQ interference plasmid to A549 cells.Filter out the highest interference efficiency plasmid by detecting the mRNA and protein levels using RT-PCR and Western blot methods.Results:We successfully design and built three TNFAIP8-shRNA-pSIREN-RetroQ interference plasmids,and screen out the highest efficiency interference plasmid.Conclusion: Three interference plasmids targeting the TNFAIP8 gene have been constructed successfully and provide a useful tool for studying the function of TNFAIP8.
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Background Thyroid-associated ophthalmopathy (TAO) is a kind of clinically common and incurable ocular disease,and its incidence is at top place.The etiology and pathologic mechanism of TAO are still unknown because of shortness of replicative animal models and difficulty to acquire the ocular tissues in the early stage of the disease.To better understand the pathogenesis of TAO and investigate effective treatable measures, an appropriate animal model should be developed.Objective This study was to immunize female BALB/c mice with the recombinant plasmid of human thyroid-stimulating hormone receptor (TSHR) extracellular domain in cationic liposomes for the establishement of TAO models.Methods Thirty-two 6-to 8-week-old female BALB/c mice were randomly assigned to four groups according to computer random allocation.pcDNA3.1 +/hTSHR289 of 100 μg in an adjuvant cationic liposomes was injected via anterior tibialis muscle and peritoneal cavity separately in the recombinant plasmid injection group in 0, 3,6 weeks, and pcDNA3.1 or cationic liposomes was injected in the liposomes injection group or the blank plasmid group in the same way, respectively, and normal saline solution was injected in the blank control group.Body weight of the mice was measued before and 1 month,2,3 and 4 months after initial injection.The manifestations were observed after modeling.The mice were sacrificed 17 weeks after initial injection,and the histopathology examination was carried out on the thyroid gland and orbital tissue.The heart blood was collected from the mice,and serum contents of total thyroxin 4 (TT4) and thyroid-stimulating hormone (TSH)were assayed by ELISA.Results Protrusion, eyelid swell and keratitis occurred in 12 eyes of 6 mice in the recombinant plasmid injection group after immunization.A significant difference in the body weight of the mice was found among the blank control group, blank plasmid group, liposomes injection group and recombinant plasmid injection group (Fgroup =3.425, P =0.028), and the body weight was considerably reduced in the recombinant plasmid injection group in comparison with the blank control group, blank plasmid group,liposomes injection group (Ftime =0.838 ,P=0.023).The serum levels of TT4 were (7.75±1.00), (7.96±0.76), (6.76±1.10) and (4.43±2.88) μg/dlin the blank control group, liposomes injection group, blank plasmid group, and recombinant plasmid injection group, and those of TSH were (6.36±2.58),(4.83±3.96),(6.63±1.71) and (1.60 ±1.76) ng/ml, showing significant differences among the groups (F =7.150, P＜0.001;F =5.521, P＜0.01) , and the serum levels of TT4 and TSH were remarkably lower in the recombinant plasmid injection group than those of the blank control group,liposomes injection group and blank plasmid group (all at P ＜ 0.05).Histopathology revealed the lymphocyte infiltration of thyroid gland in 6 mice and proliferation of orbital adipose tissue, infiltration of lymphocytes and mastocytes,deposition of hyaluronic acid as well as swell, breakage and inflammatory cell infiltration of extraocular muscle in 15 eyes of the recombinant plasmid injection group.Conclusions A murine model of TAO can be successfully induced by immunization with recombination plasmid pcDNA3.1 +/hTSHR289 and cationic liposomes.The histopathology characteristics and ocular findings of the animal models are similar to human TAO.
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Objective To construct recombinant plasmids of SIK2 cDNA and its truncated mutants and induce its expression in E.coil.Methods We designed primers of SIK2 and its truncated mutants.The gene fragments of SIK2,SIK2-Δ1 (280-926),SIK2-Δ2 (400-926),SIK2-Δ3 (1-400),and SIK2-Δ4 (700-926)were amplified by polymerase chain reaction (PCR)and cloned into pGEX-4T-2 vector to construct recombinant plasmids with GST. The plasmids were transformed into E.coil BL2 1 respectively,and induced with IPTG to express fusion protein. The results were confirmed by Coomassie blue staining and Western blot.Results We successfully constructed recombinant plasmid of SIK2 cDNA and its truncated mutants.Coomassie blue staining and Western blot resutls showed that these plasmids were induced to be expressed in E.coil BL21.Conclusion SIK2 cDNA and its truncated mutants were overexpressed in E.coil BL2 1 ,which lays expereimental foundation for further study on the function of each domain of SIK2 .
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Objective To construct a recombinant plasmid carrying phoS2 from Mycobacterium tuberculosis, to express prokaryotically,to purify the recombinant protein and to identify the immunogenicity of its recombinant protein.Methods phoS2 gene was subcloned into expression vector pET32a.The constructed recombinant plasmid phoS2/pET32a was transformed to E.coli BL21 (DE3)for expression under induction of IPTG.The expressed product was identified by SDS-PAGE and then purified by His-bind affinity chromatography with Ni2+.Results of the induced expression level were detected by SDS-PAGE. The recombinant protein was purified by affinity chromatography.The biological activity of phoS2 was tested by Western blot;its secondary structure and 3-D structure were predicted with software packages such as DNAstar and Rasmol.Results The recombinant plasmid phoS2/pET32a of Mycobacterium tuberculosis was constructed successfully and confirmed by restriction endonuclease analysis and DNA sequencing analysis. SDS-PAGE analysis showed that the expressed proteins were mainly insoluble;Western blot analysis showed that the molecular weight of phoS2 recombinants protein was 3 7 9 5 3 u.The recombinant protein was purified by affinity chromatography.Analysis of the predicted protein indicated that the molecular mass was 37 953.1 ku,PI was 5.75,there was one transmembrane region and function sites were 1 to 370. Conclusion The recombinant plasmid phoS2/pET32a of Mycobacterium tuberculosis was successfully constructed and phoS2 gene could be expressed in BL2 1 with high efficiency.Predicting protein structure and function can provide some theoretical basis for conducting the present experiment and selecting further research.
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Objective The gene expression data of T lymphoblastic leukemia cell lines were obtained by " high-throughput sequencing",a new sequence was found,which called J441.The aim of this study was to establish a recombinant lentivirus harboring J441 gene and FLAG-tagged peptide.Methods We got gene expression data from Jurkat by "high-throughput sequencing".A new gene was found by bioinformatic analysis,we called it J441.For further study,a FLAG-J441 fusion gene was constructed by real-time polymerase chain reaction(RT-PCR) and packaged into pHAGE-CMV-MCS-Izs-Green lentivirus vector.The recombinant plasmid pHAGE-J441-FLAG was identified by PCR and sequencing.The recombinant plasmid,packaging vector psPAX2 and envelope vector pMD2.G were co-transfected into 293T cells and the resulting lentivirus was collected.After infection of the recombinant lentivirus,the expression of J441 in 293T was investigated by the expression of ZsGreen and sequencing.The expression of FLAG was investigated by immunofluorescence.Results A recombinant lentivirus plasmid pHAGE-J441-FLAG was successfully constructed.The viral titer was 5 × 1010 ifu/L.The expression of J441 in 293T could be detected by the expression of ZsGreen and sequencing.Immunofluorescence showed that FLAG was expressed in cytoplasm.Conclusions The lentivirus-based delivery system has been successfully constructed.Exogenous J441-FLAG can be stably expressed.The result of immunofluorescence suggest that the J441 gene might be expressed in cytoplasm.
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Objective To clone silent information regulator 1 (SIRT1) gene full-length cDNA,construct recombinant eukaryotic expression vector containing SIRT1 gene and its mutant T200I,E420K,so as to lay the foundation for further research of SIRT1 gene function.Methods RT-PCR amplified SIRT1 gene full-length cDNA.PCR products were cloned into the eukaryotic expression vector pcDNA3.1 (+) through double digestion and pcDNA3.1(+)-SIRT1 recombinant plasmid was obtained.Meanwhile,site-directed mutagenesis was applied to build its mutant pcDNA3.1 (+)-T200I and pcDNA3.1 (+)-E420K expression vector.Recombinant plasmid was identified by enzyme digestion and DNA sequencing and the recombinant eukaryotic expression vector of success was screened out.Results SIRT1 gene full-length cDNA was successfully cloned,and pcDNA3.1 (+)-SIRT1 eukaryotic expression vector and its mutant were also successfully constructed.Positive recombinant plasmid sequencing was compared after enzyme digestion,and it was completely consistent with the expected sequence.Transfected 293T cell line was established and HIS tagged SIRT1 protein was expressed.Conclusions We successfully constructed pcDNA3.1 (+)-SIRT1 and its mutant pcDNA3.1 (+)-T200I,pcDNA3.1 (+)-E420K eukaryotic expression vector,which may provide genetic material for biological function study of SIRT1 gene and its mutant T200I,E420K.