EgMADS3 directly regulates EgLPAAT to mediate medium-chain fatty acids (MCFA) anabolism in the mesocarp of oil palm.

KEY MESSAGE: EgMADS3, a pivotal transcription factor, positively regulates MCFA accumulation via binding to the EgLPAAT promoter, advancing lipid content in mesocarp of oil palm. Lipids function as the structural components of cell membranes, which serve as permeable barriers to the external environment of cells. The medium-chain fatty acid in the stored lipids of plants is an important renewable energy. Most research on MCFA production in plant lipid synthesis is based on biochemical methods, and the importance of transcriptional regulation in MCFA synthesis and its incorporation into TAGs needs further research. Oil palm is the most productive oil crop in the world and has the highest productivity among the main oil crops. In this study, the MADS transcription factor (EgMADS3) in the mesocarp of oil palm was characterized. Through the VIGS-virus induced gene silencing, it was determined that the potential target gene of EgMADS3 was related to the biosynthesis of medium-chain fatty acid (MCFA). Transient transformation in protoplasts and qRT-PCR analysis showed that EgMADS3 positively regulated the expression of EgLPAAT. The results of the yeast one-hybrid assays and EMSA indicated the interaction between EgMADS3 and EgLPAAT promoter. Through genetic transformation and fatty acid analysis, it is concluded that EgMADS3 directly regulates the mid-chain fatty acid synthesis pathway of the potential target gene EgLPAAT, thus promotes the accumulation of MCFA and improves the total lipid content. This study is innovative in the functional analysis of the MADS family transcription factor in the metabolism of medium-chain fatty acids (MCFA) of oil palm, provides a certain research basis for improving the metabolic pathway of chain fatty acids in oil palm, and improves the synthesis of MCFA in plants. Our results will provide a reference direction for further research on improving the oil quality through biotechnology of oil palm.

A regimen based on the combination of trimethoprim/sulfamethoxazole with caspofungin and corticosteroids as a first-line therapy for patients with severe non-HIV-related pneumocystis jirovecii pneumonia: a retrospective study in a tertiary hospital.

BACKGROUND: Pneumocystis jirovecii pneumonia (PJP) is a life-threatening and severe disease in immunocompromised hosts. A synergistic regimen based on the combination of sulfamethoxazole-trimethoprim (SMX-TMP) with caspofungin and glucocorticosteroids (GCSs) may be a potential first-line therapy for PJP. Therefore, it is important to explore the efficacy and safety of this synergistic therapy for treating non-HIV-related PJP patients. METHODS: We retrospectively analysed the data of 38 patients with non-HIV-related PJP at the First Affiliated Hospital of Xi'an Jiaotong University. Patients were divided into two groups: the synergistic therapy group (ST group, n = 20) and the monotherapy group (MT group, n = 18). All patients were from the ICU and were diagnosed with severe PJP. In the ST group, all patients were treated with SMX-TMP (TMP 15-20 mg/kg per day) combined with caspofungin (70 mg as the loading dose and 50 mg/day as the maintenance dose) and a GCS (methylprednisolone 40-80 mg/day). Patients in the MT group were treated only with SMX-TMP (TMP 15-20 mg/kg per day). The clinical response, adverse events and mortality were compared between the two groups. RESULTS: The percentage of patients with a positive clinical response in the ST group was significantly greater than that in the MT group (100.00% vs. 66.70%, P = 0.005). The incidence of adverse events in the MT group was greater than that in the ST group (50.00% vs. 15.00%, P = 0.022). Furthermore, the dose of TMP and duration of fever in the ST group were markedly lower than those in the MT group (15.71 mg/kg/day vs. 18.35 mg/kg/day (P = 0.001) and 7.00 days vs. 11.50 days (P = 0.029), respectively). However, there were no significant differences in all-cause mortality or duration of hospital stay between the MT group and the ST group. CONCLUSIONS: Compared with SMZ/TMP monotherapy, synergistic therapy (SMZ-TMP combined with caspofungin and a GCS) for the treatment of non-HIV-related PJP can increase the clinical response rate, decrease the incidence of adverse events and shorten the duration of fever. These results indicate that synergistic therapy is effective and safe for treating severe non-HIV-related PJP.

Adjuvant DNA vaccine pNMM promotes enhanced specific immunity and anti-tumor effects.

DNA vaccines containing only antigenic components have limited efficacy and may fail to induce effective immune responses. Consequently, adjuvant molecules are often added to enhance immunogenicity. In this study, we generated a tumor vaccine using a plasmid encoding NMM (NY-ESO-1/MAGE-A3/MUC1) target antigens and immune-associated molecules. The products of the vaccine were analyzed in 293 T cells by western blotting, flow cytometry, and meso-scale discovery electrochemiluminescence. To assess the immunogenicity obtained, C57BL/6 mice were immunized using the DNA vaccine. The results revealed that following immunization, this DNA vaccine induced cellular immune responses in C57BL/6 mice, as evaluated by the release of IFN-γ, and we also detected increases in the percentages of nonspecific lymphocytes, as well as those of antigen-specific T cells. Furthermore, immunization with the pNMM vaccine was found to significantly inhibit tumor growth and prolonged the survival of mice with B16-NMM+-tumors. Our data revealed that pNMM DNA vaccines not only confer enhanced immunity against tumors but also provide a potentially novel approach for vaccine design. Moreover, our findings provide a basis for further studies on vaccine pharmacodynamics and pharmacology, and lay a solid foundation for clinical application.

Activation of endogenous retrovirus triggers microglial immuno-inflammation and contributes to negative emotional behaviors in mice with chronic stress.

BACKGROUND: The "missing" link of complex and multifaceted interplay among endogenous retroviruses (ERVs) transcription, chronic immuno-inflammation, and the development of psychiatric disorders is still far from being completely clarified. The present study was aimed to investigate the mechanism of protective role of inhibiting ERVs on reversing microglial immuno-inflammation in basolateral amygdala (BLA) in chronic stress-induced negative emotional behaviors in mice. METHODS: Male C57BL/6 mice were exposed to chronic unpredictable mild stress (CUMS) for 6 w. Negative emotional behaviors were comprehensively investigated to identify the susceptible mice. Microglial morphology, ERVs transcription, intrinsic nucleic acids sensing response, and immuno-inflammation in BLA were assessed. RESULTS: Mice with chronic stress were presented as obviously depressive- and anxiety-like behaviors, and accompanied with significant microglial morphological activation, murine ERVs genes MuERV-L, MusD, and IAP transcription, cGAS-IFI16-STING pathway activation, NF-κB signaling pathway priming, as well as NLRP3 inflammasome activation in BLA. Antiretroviral therapy, pharmacological inhibition of reverse transcriptases, as well as knocking-down the ERVs transcriptional regulation gene p53 significantly inhibited microglial ERVs transcription and immuno-inflammation in BLA, as well as improved the chronic stress-induced negative emotional behaviors. CONCLUSIONS: Our results provided an innovative therapeutic approach that targeting ERVs-associated microglial immuno-inflammation may be beneficial to the patients with psychotic disorders.

Association of H3K9me3 with breast cancer prognosis by estrogen receptor status.

BACKGROUND: Cellular experiments revealed that a decreased histone H3 lysine 9 trimethylation (H3K9me3) level was associated with the upregulation of oncogenes in breast cancer cells. Moreover, the role of H3K9me3 in breast cancer was closely associated with estrogen receptor (ER) status. Therefore, we aimed to examine the prognostic value of H3K9me3 on breast cancer by ER status. The level of H3K9me3 in tumors were evaluated with tissue microarrays by immunohistochemistry for 917 women diagnosed with primary invasive breast cancer. Hazard ratios (HRs) and their 95% confidence intervals (CIs) for overall survival (OS) and progression-free survival (PFS) were estimated using Cox regression models. Interaction between H3K9me3 and ER on the prognosis was assessed on multiplicative scale. RESULTS: The level of H3K9me3 in tumor tissues was lower than that in adjacent tissues. The high level of H3K9me3 was associated with a better OS (HR = 0.43, 95% CI: 0.21-0.86) and PFS (HR = 0.49, 95% CI: 0.29-0.81) among only ER-positive but not ER-negative tumors. Moreover, the interaction between the level of H3K9me3 and ER status (negative and positive) on the prognosis was significant (Pinteraction = 0.011 for OS; Pinteraction = 0.022 for PFS). Furthermore, the ER-positive tumors were stratified by ER-low and ER-high positive tumors, and the prognostic role of H3K9me3 was significant among only ER-high positive patients (HR = 0.34, 95% CI: 0.13-0.85 for OS; HR = 0.47, 95% CI: 0.26-0.86 for PFS). CONCLUSIONS: Our study showed that the prognostic value of H3K9me3 on breast cancer was related to ER status and expression level, and the high level of H3K9me3 was associated with a better prognosis among ER-positive tumors, particularly ER-high positive tumors.

MiR-501-5p alleviates cardiac dysfunction in septic patients through targeting NR4A3 to prevent its binding with Bcl-2.

Sepsis-induced myocardial dysfunction is a common complication in septic patients. To date, a limited number of biomarkers that could predict cardiomyocyte apoptosis have been explored. In this study, we successfully established a cecal ligation and puncture (CLP)-induced septic model, and it was found that miR-501-5p expression was down-regulated in peripheral blood samples of septic patients with cardiac dysfunction, lipopolysaccharide (LPS)-induced cardiomyocytes, and the myocardium and peripheral blood in the septic model. Moreover, it was revealed that miR-501-5p overexpression could increase left ventricular diastolic pressure (LVDP), fractional shortening (FS), ejection fraction (EF), and maximum rate of the rise of left ventricular pressure (+dp/dt) in vivo, while it decreased the levels of myocardial injury-related indicators. In addition, LPS induction accelerated apoptosis and elevated the inflammation in HL-1 and HCM cells, which could be reversed by miR-501-5p overexpression. Mechanistically, we considered nuclear receptor subfamily 4 group A member 3 (NR4A3) as the target of miR-501-5p, and it was found that miR-501-5p prevented the binding between NR4A3 and Bcl-2. It was found that miR-501-5p exerted an inhibitory effect on cardiomyocyte apoptosis and inflammation in a NR4A3-dependent manner. Overall, our results may provide evidence for consideration of miR-501-5p in the therapy of sepsis.

Effectiveness of the improved B-ultrasound method for measuring the antral section to guide enteral nutrition in patients with sepsis in a randomized controlled trial.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the application of the improved B-ultrasound method (hereafter referred to as B method) for measuring the antral section to evaluate gastric motility in guiding EN for patients with sepsis. METHODS AND STUDY DESIGN: In this single-center, non-blinded, randomized controlled trial, 64 patients with sepsis were randomly enrolled from January 2018 to December 2019. The improved B method (study group) and physicians' clinical experience (control group) were used to guide EN. The two groups patients were separated randomly both. RESULTS: Compared with the control group, the study group had a significantly shorter EN start time, faster initial rate of EN, lower incidence of EN interruption, and shorter Tmax (p<0.05,95% confidence intervals.) and exhibited lower incidences of adverse reactions (p<0.05). Kaplan-Meier survival analysis demonstrated that the study group exhibited significantly fewer adverse EN complications (p=0.029), shorter MV duration, and decreased ICU stay and in-hospital mortality (p<0.05). CONCLUSIONS: The improved B method could perform real-time monitoring of gastric function. Additionally, compared with the physician's personal clinical experience, the improved B method exhibits a better effect in guiding EN for patients with sepsis.

Prognostic value of the combined variability of mean platelet volume and neutrophil percentage for short-term clinical outcomes of sepsis patients.

INTRODUCTION: In this single center retrospective cohort study, 784 patients with sepsis were enrolled and followed up for at least 30 days. The selected endpoint was an all-cause mortality event. METHOD: The relationship between MPV-CV + NEU%-CV and all-cause mortality (in-hospital and 30-day) was analyzed by categorizing the patients into four groups according to MPV-CV and NEU%-CV values. For in-hospital mortality, a significantly higher risk of mortality was observed in patients with an MPV-CV ≥ 15.00% + NEU%-CV ≥ 16.00% than in patients of the other groups (P < 0.001). After adjustment for age, sex, body mass index (BMI), infection site, Acute Physiology and Chronic Health Evaluation (APACHE) II score, Sequential Organ Failure Assessment (SOFA) score, use of vasoactive drugs, mechanical ventilation and renal replacement therapy (RRT), hematocrit, albumin, procalcitonin (PCT), and lactate, logistic regression analysis revealed that an MPV-CV ≥ 15.00% + NEU%-CV ≥ 16.00% was an independent predictive factor for in-hospital mortality [adjusted model: odds ratio (OR) = 4.48, 95% CI = 2.92-6.88, P = 0.001]. RESULTS: After adjustment for age, sex, BMI, infection site, APACHE II score, SOFA score, hematocrit, albumin, PCT, lactate, and the use of vasoactive drugs, mechanical ventilation, and RRT, Cox proportional-hazards regression model revealed that an MPV-CV ≥ 15.00% + NEU%-CV ≥ 16.00% was an independent predictive factor for 30-day mortality [adjusted model 1: hazard ratio (HR) = 7.69, 95% CI = 4.15-14.24, P < 0.001; adjusted model 2: HR = 4.07, 95% CI = 2.50-6.62, P < 0.001]. CONCLUSION: The combination of MPV-CV and NEU%-CV provides a good prognostic value and is a strong independent predictor of short-term clinical outcomes in patients with sepsis. An MPV-CV ≥ 15.00% + NEU%-CV ≥ 16.00% is significantly associated with adverse short-term clinical outcomes.Trial registration number is XJTU2AF2016LSY-04, the registration date is December 2018.

Voriconazole therapeutic drug monitoring in critically ill patients improves efficacy and safety of antifungal therapy.

Since voriconazole plasma trough concentration (VPC) is related to its efficacy and adverse events, therapeutic drug monitoring (TDM) is recommended to perform. However, there is no report about the data of voriconazole TDM in critically ill patients in China. This retrospective study was performed to determine whether voriconazole TDM was associated with treatment response and/or voriconazole adverse events in critically ill patients, and to identify the potential risk factors associated with VPC. A total of 216 critically ill patients were included. Patients were divided into two groups: those underwent voriconazole TDM (TDM group, n = 125) or did not undergo TDM (non-TDM group, n = 91). The clinical response and adverse events were recorded and compared. Furthermore, in TDM group, multivariate logistic regression analysis was performed to identify the possible risk factors resulting in the variability in initial VPC. The complete response in the TDM group was significantly higher than that in the non-TDM group (P = .012). The incidence of adverse events strongly associated with voriconazole in the non-TDM group was significantly higher than that in the TDM group (19.8% vs 9.6%; P = .033). The factors, including age (OR 0.934, 95% CI: 0.906-0.964), male (OR 5.929, 95% CI: 1.524-23.062), serum albumin level (OR 1.122, 95% CI: 1.020-1.234), diarrhoea (OR 4.953, 95% CI: 1.495-16.411) and non-intravenous administration (OR 4.763, 95% CI: 1.576-14.39), exerted the greatest effects on subtherapeutic VPC (VPC < 1.5 mg/L) in multivariate analysis. Intravenous administration (OR 7.657, 95% CI: 1.957-29.968) was a significant predictor of supratherapeutic VPC (VPC > 4.0 mg/L). TDM can result in a favourable clinical efficacy and a lower incidence of adverse events strongly associated with voriconazole in critically ill patients. Subtherapeutic VPC was closely related to younger age, male, hyperalbuminaemia, diarrhoea and non-intravenous administration, and intravenous administration was a significant predictor of supratherapeutic VPC.

LncRNA RMRP accelerates hypoxia-induced injury by targeting miR-214-5p in H9c2 cells.

OBJECTIVE: To elucidate the function of lncRNA RMRP in hypoxia-induced acute myocardial infarction (AMI) in vitro and explore its underlying mechanism. METHODS: Hypoxic injury was confirmed by measurement of cell viability, LDH release, migration, invasion, and apoptosis in H9c2 cells. The interactions between RMRP and miR-214-5p as well as miR-214-5p and p53 were also investigated. RESULTS: Hypoxia treatment significantly induced cell damage in H9c2 cells, accompanied with the up-regulation of RMRP expressions. Transfection of RMRP siRNA remarkably attenuated hypoxia-induced injury by enhancing cell viability, migration and invasion, and reducing cell apoptosis and LDH release; whereas, enforced expression of RMRP aggravated hypoxia-induced injury. Furthermore, RMRP served as an endogenous sponge for miR-214-5p, and its expression was negatively regulated by RMRP. The effects of RMRP knockdown on hypoxia-induced injury were further enhanced with miR-214-5p overexpression, but significantly abrogated with miR-214-5p silence. Moreover, p53 was verified as a direct target of miR-214-5p, and functional investigation revealed that RMRP regulated hypoxia-induced injury via modulating p53 signaling pathway, which was partially mediated by miR-214-5p. CONCLUSION: Our findings demonstrated the novel molecular mechanism of RMRP/miR-214-5p/p53 axis on the regulation of hypoxia-induced myocardial injury in H9c2 cells, which might provide potential therapeutic targets for AMI treatment.

Minocycline promotes cardiomyocyte mitochondrial autophagy and cardiomyocyte autophagy to prevent sepsis-induced cardiac dysfunction by Akt/mTOR signaling.

Myocardial damage is responsible for the high mortality of sepsis. However, the underlying mechanism is not well understood. Cardiomyocyte autophagy alleviates the cardiac injury caused by myocardial infarction. Enhanced cardiomyocyte autophagy also has protective effects against cardiomyocyte mitochondrial injury. Minocycline enhances autophagy in many types of cells under different types of pathological stress and can be easily taken up by cardiomyocytes. The present study investigated whether minocycline prevented myocardial injury caused by sepsis and whether cardiomyocyte autophagy participated in this process. The results indicated that minocycline enhanced cardiomyocyte mitochondrial autophagy and cardiomyocyte autophagy and improved myocardial mitochondrial and cardiac function. Minocycline upregulated protein kinase B (Akt) phosphorylation, inhibited mTORC1 expression and enhanced mTORC2 expression. In conclusion, minocycline enhanced cardiomyocyte mitochondrial autophagy and cardiomyocyte autophagy and improved cardiac function. The underlying mechanisms were associated with mTORC1 inhibition and mTORC2 activation. Thus, our findings suggest that minocycline may represent a potential approach for treating myocardial injury and provide novel insights into the underlying mechanisms of myocardial injury and dysfunction after sepsis.

[Construction and application of plasmid pVAX-HBVE harboring hepatitis B surface antibody targeted interferon and interleukin 12 genes].

OBJECTIVE: To construct a new gene therapy plasmid that can express both hepatitis B surface antibody(HBsAb) targeted interferon (dsFvα) and human interleukin 12 (hIL-12) genes for the immunotherapy of chronic hepatitis B. METHODS: The pEE14.1-dsFvα plasmid was digested to obtain dsFvα fragment, and then the fragment was cloned into the upstream of IRES sequence in vector pVAX-IRES-hIL-12 digested by the same enzyme to construct the recombinant expression plasmid pVAX-HBVE. The recombinant plasmid was transiently transfected into the HEK293T cells and the expression of target gene was detected by ELISA. The recombinant plasmid pVAX-HBVE was extracted and injected into the leg muscles of HBV transgenic mice with electroporation delivery. The HBV gene copies were detected by quantitative PCR before and after injection. RESULTS: Enzyme digestion and sequencing analysis showed that the recombinant plasmid pVAX-HBVE was constructed as expected before. ELISA showed that dsFvα gene and IL-12 gene were successfully expressed in the supernatant of transfected cells. The recombinant plasmid pVAX-HBVE (30 µg, once) reduced the HBV gene copy by two orders of magnitude after being injected into transgenic mice. CONCLUSION: The neo-type immune gene therapy plasmid was successfully constructed, which would provide an alternative for immune gene therapy of chronic hepatitis B.

[Expression and activity identification of a fusion protein for promoting adenovirus infection efficiency of dendritic cells].

OBJECTIVE: To construct a prokaryotic expression plasmid for CT40L, express the target protein in E. coli, purity the CT40L fusion protein and verify its antigenicity. METHODS: Gene sequences of Coxsackie and adenovirus receptor (CAR), bacteriophage T4 fibritin and mouse CD40L were found out in GenBank. Then functional domains of three molecules were linked to form a fusion sequence which was then optimized for prokaryotic expression. The optimized sequence was cloned into prokaryotic expression vector pET42a(+) to construct the recombinant expression vector pET42a-CT40L. The recombinant vector was transformed into BL21 (DE3) and the fusion protein CT40L/GST was induced by IPTG. The fusion protein was then subjected to purification using GST affinity chromatography and to identification of the immune activity using Western blotting and ELISA. RESULTS: The recombinant expression vector was verified correct by double digestion with Nco I and EcoR I. After IPTG induction, SDS-PAGE showed that the relative molecular mass of the fusion protein was about 78 kDa and that the purity of the purified protein reached 90%. Western blotting and ELISA demonstrated that the purified fusion protein had a valid antigenicity. CONCLUSION: The prokaryotic expression plasmid pET42a-Ct40L was successfully constructed and expressed in E. coli, and the purified fusion protein was proved to have a good antigenicity.

Enhancement of antitumor immunity using a DNA-based replicon vaccine derived from Semliki Forest virus.

A DNA-based replicon vaccine derived from Semliki Forest virus, PSVK-shFcG-GM/B7.1 (Fig. 1a) was designed for tumor immunotherapy as previously constructed. The expression of the fusion tumor antigen (survivin and hCGß-CTP37) and adjuvant molecular protein (Granulocyte-Macrophage Colony-Stimulating Factor/ GM-CSF/B7.1) genes was confirmed by Immunofluorescence assay in vitro, and immunohistochemistry assay in vivo. In this paper, the immunological effect of this vaccine was determined using immunological assays as well as animal models. The results showed that this DNA vaccine induced both humoral and cellular immune responses in C57BL/6 mice after immunization, as evaluated by the ratio of CD4+/CD8+ cells and the release of IFN-γ. Furthermore, the vaccination of C57BL/6 mice with PSVK-shFcG-GM/B7.1 significantly delayed the in vivo growth of tumors in animal models (survivin+ and hCGß+ murine melanoma, B16) when compared to vaccination with the empty vector or the other control constructs (Fig. 1b). These data indicate that this type of replicative DNA vaccine could be developed as a promising approach for tumor immunotherapy. Meanwhile, these results provide a basis for further study in vaccine pharmacodynamics and pharmacology, and lay a solid foundation for clinical application.

[Influence of electroporation on immunogenicity of the DNA vaccine pVAX-tG250FcGB].

OBJECTIVE: To investigate the influence of electroporation on the immunogenicity of the DNA vaccine pVAX- tG250FcGB. METHODS: The DNA vaccine pVAX-tG250FcGB was constructed by inserting the coding gene of tG250 fusion genes into the expression vector pVAX. The DNA vaccine was delivered in BALB/c mouse by electroporation or intramuscular injection, and the induced antigen specific immune responses were compared. RESULTS: The vaccine delivered by electroporation and intramuscular injection both induced immune responses in BALB/c mouse, but electroporation produced an obviously stronger effect than intramuscular injection. CONCLUSION: Electroporation-mediated DNA vaccine delivery can produce strong immune response in mice and is an effective means for studying the immunogenic effect of DNA vaccine pVAX-tG250FcGB.

[Cloning, prokaryotic expression, and antigenicity identification of extracellular domain of mouse CD40].

OBJECTIVE: To construct a prokaryotic expression plasmid for extracellular domain of mouse CD40 (mCD40), express the mCD40/GST recombinant protein in E.coli, purify the mCD40/GST recombinant protein and characterize its antigenicity. METHODS: Extracellular domain of mouse CD40 was amplified by PCR from cell line DC2.4 and then was cloned into prokaryotic expression vector pGEX-6P-1 to construct the recombinant expression vector pGEX-6P-1-mCD40. The expression vector was transformed into E.coli BL21 (DE3) and the fusion protein mCD40/GST was induced by IPTG. The fusion protein was purified through sepharose 4B. Then antigenicity of the purified mCD40/GST protein was verified by Western blotting and ELISA. RESULTS: The PCR product was verified by DNA sequencing to be consistent with the sequence of mouse CD40 on GenBank. The recombinant plasmid was identified by double digestion successfully. SDS-PAGE analysis showed the relative molecular mass of the fusion protein induced by IPTG was 45 000. Western blotting and ELISA demonstrated that the purified mCD40/GST protein had a good antigenicity. CONCLUSION: The prokaryotic expression plasmid pGEX-6P-1-mCD40 was constructed successfully. In E.coli BL21 (DE3) transformed with the plasmid, the mCD40/GST fusion protein was expressed by IPTG induction. The purified mCD40/GST fusion protein had a high antigenicity, which provides a strong support for the future study of CD40.

[Construction and identification of a recombinant replication-defective adenovirus vector encoding p53AIP1 and its expression in human HeLa cells].

OBJECTIVE: To construct a recombinant replication-defective adenovirus vector carrying p53AIP1 (p53-regulated apoptosis-inducing protein 1) gene and observe its expression in human HeLa cells. METHODS: Specific primers were designed according to p53AIP1 gene sequence and inserted specific enzyme cutting sites. P53AIP1 gene was amplified by PCR and cloned into the adenovirus shuttle plasmid pDC316 to construct the recombinant vector pDC316-p53AIP1, which was co-transfected with helper plasmid pBHGloxδE1, 3Cre into HEK293 cells by Lipofectamine(TM); 2000. The recombinant replication-defective adenovirus (Ad-p53AIP1) was generated by means of homologous recombination of the two plasmids in HEK293 cells with the Cre-loxP recombinase system and harvested after 12 days. Ad-p53AIP1 and Ad-null were respectively transfected into HeLa cells at MOI=100. Then the expression of p53AIP1 gene was detected by Western blotting. RESULTS: pDC316-p53AIP1 was constructed successfully. The new constructed vector was confirmed by PCR analysis, double enzyme digestion and DNA sequencing. The results were in conformity with the expected. Western blotting demonstrated that the target p53AIP1 proteins were effectively expressed in the transfected HeLa cells. CONCLUSION: The recombinant adenovirus vector of Ad-p53AIP1 was successfully established, and it was proved to have a strong ability of infectivity.

[Prokaryotic expression, purification and antigenicity identification of recombinant human survivin protein].

OBJECTIVE: To construct a prokaryotic expression plasmid pET28a-survivin, optimize the recombinant protein expression conditions in E.coli, and purify the survivin recombinant protein and identify its antigenicity. METHODS: Survivin cDNA segment was amplified by PCR and cloned into prokaryotic expression vector pET28a(+) to construct the recombinant expression vector pET28a-survivin. The expression vector was transformed into BL21 (DE3) and the fusion protein survivin/His was induced by IPTG. The fusion protein was purified through Ni affinity chromatography. The antigenicity of the purified survivin protein was identified by Western blotting and ELISA. RESULTS: The recombinant expression vector was verified successfully by BamHI and HindIII. The fusion protein induced by IPTG was obtained with Mr; about 24 000. The purity of the purified protein reached 90% by SDS-PAGE analysis. And the antigenicity of the survivin protein was validated by Western blotting and ELISA. CONCLUSION: The prokaryotic expression plasmid pET28a-survivin was successfully constructed and the survivin protein was expressed and purified in E.coli. The antigenicity of the purified survivin protein was demonstrated desirable.

[Construction and application of the replicon DNA recombinant plasmid pSVK-luc].

OBJECTIVE: To study the expression of the replicon DNA vaccine in vivo by constructing a recombinant plasmid containing luciferase reporter gene on the basis of the Semiliki forest virus (SFV) replicon vector (pSVK-luc). METHODS: The luciferase gene fragment was amplified by PCR and cloned into the SFV replicon vector pSVK. The recombinant plasmid pSVK-luc was identified and screened by enzyme digestion and sequencing for the positive one. By chemical-based transfection, the positive plasmid was transferred into human embryonic kidney 293T cells to observe the expression of luciferase gene by flow cytometry and immunofluorescence. By electroporation, the plasmid was delivered into BALB/c mouse quadriceps femoris muscles to detect the expression of target gene by in vivo imaging system. RESULTS: Sequencing revealed that the recombinant plasmid pSVK-luc we obtained was identical with the expected one. Flow cytometry and immunofluorescence showed that the expression of the luciferase gene in 293T cells and in vivo imaging system presented that the expression in the immunized mouse muscles. CONCLUSION: A novel replicative DNA pSVK-luc has been successfully constructed, and can be expressed in 293T cells and in the muscle tissues of immunized mice, which provides a basis for future studies on the mechanism underlying the replicon DNA vaccine works in vivo and on the optimal electroporation conditions for the replicon DNA vaccine delivery in vivo.

[Prokaryotic expression, purification and antigenicity identification of human renal cell carcinoma-associated antigen G250].

OBJECTIVE: To amplify human renal cell carcinoma (RCC)-associated antigen G250 gene and construct a recombinant plasmid pET-42a-hG250, express and purify human G250 protein and identify its antigenicity. METHODS: The gene of human G250 was amplified from pGEM-T-G250 by PCR. After sequencing, the PCR product (112-1242 bp) was cloned into pET-42a prokaryotic expression vector to construct the recombinant plasmid pET-42a-hG250. The plasmid was transformed into BL21 (DE3) and human G250 protein was expressed under the induction of IPTG. The fusion protein was purified and identified by SDS-PAGE, Western blotting and ELISA sequentially. RESULTS: The human G250 prokaryotic expression vector pET-42a-hG250 was successfully constructed as confirmed by enzyme digestion and DNA sequencing. After transformation into BL21 (DE3), the target protein was successfully induced to express and purified as expected. Western blotting and ELISA demonstrated that the purified human G250 protein had a desirable immunogenicity. CONCLUSION: The recombinant prokaryotic expression vector pET-42a-hG250 has been constructed successfully. The purified human G250 protein has a good antigenicity.