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.

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.

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.

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.

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.

The search for optimal nocturnal diurnal heart rate Index targets in ICU patients: a retrospective observational study from large ICU database.

Background: Circadian rhythms play a crucial role in cardiovascular health, with the nocturnal diurnal heart rate index (NDHRI) reflecting significant circadian variations. However, the optimal NDHRI target in Intensive Care Unit (ICU) patients remains undefined. This study aims to establish an evidence-based NDHRI target range and assess its association with mortality. Methods: Data from the eICU Collaborative Research Database (n = 32,412) were analyzed. NDHRI was calculated by dividing cumulative nighttime heart rate area by daytime area. Generalized additive models (GAMs) explored the non-linear relationship between mean NDHRI and mortality, adjusting for confounders. Subgroup analyses were conducted based on ethnicity, ICU type, and comorbidities. Results: A U-shaped association was observed between hospital mortality and mean NDHRI (P < 0.001). The optimal NDHRI range (40.0%-45.0%) demonstrated the lowest mortality rates. The duration spent within this range correlated inversely with mortality (P < 0.001). Subgroup analyses consistently supported these findings across diverse patient profiles. Conclusions: Our findings suggest an association between maintaining NDHRI within the 40.0%-45.0% range and lower mortality rates in critically ill patients, highlighting the potential utility of monitoring circadian heart rate variations in the ICU. Further research and future randomized controlled trials are essential to confirm causality and should consider this NDHRI range as a pivotal reference target.

Design, expression and characterization of a novel coexpression system of two antiarthritic molecules.

The complexity of rheumatoid arthritis (RA) pathogenesis makes combined blockade of multiple targets an attractive therapeutic strategy. The combination therapy with anti-TNF plus anti-T-cell has been mostly reported to provide greater efficacy than anti-TNF alone. TNFR (p75)-Fc fusion protein, which has been proven effective in clinics, is chosen as the TNF antagonist in this study. CTLA4-FasL fusion molecule, which has been well characterized in our previous studies for its suppressive effect in rat arthritis model, is chosen as the T-cell antagonist. In this study, furin cleavage site and 2A self-processing sequence were introduced to link upstream TNFR-Fc and downstream CTLA4-FasL and mediate separate coexpression of the two fusion proteins in a single recombinant adeno-associated virus (rAAV) vector. Using this expression system, we generated two fusion proteins with same size as their individual counterparts in vitro and in vivo, and the proteins desirably retained their parent biological activities. In vivo results demonstrated that furin-2A technology is able to regulate separate coexpression of these proteins under arthritic inflammatory conditions. This study describes a single rAAV vector for production of two antiarthritic molecules antagonizing both TNF and T cells, which may serve as an attractive expression system for RA gene therapy.

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.

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.

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.

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.

[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.

[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.

[Prokaryotic expression, purification and antigenicity identification of mouse VEGFR2 extracellular 1-4 IgG-like domains].

OBJECTIVE: To obtain 1-4 IgG-like domains of mouse vascular endothelial growth factor receptor 2 (VEGFR2) fusion protein (mVEGFR2D1-4/GST) and identify its antiginicity and biological activity. METHODS: The gene of mVEGFR2D1-4 was amplified by RT-PCR from 14-days embryos of Balb/c mice. The PCR product was cloned into pET-42a prokaryotic expression vector to construct the recombinant plasmid pET-42a-mVEGFR2D1-4, which was transformed into E. coli BL21 (DE3) strain for mVEGFR2D1-4/GST expression. The fusion protein was identified by SDS-PAGE and Western blotting, and the antigenicity of the protein purified by affinity chromatography was characterized by ELISA. The VEGF blocking effect of the purified protein in human umbilical vein endothelial cells (HUVECs) were evaluated in in vitro cell cultures. RESULTS: The mVEGFR2D1-4 gene was obtained, which had an identical sequence to that retrieved in GenBank. The prokaryotic expression vector for mVEGFR2D1-4 was successfully constructed as confirmed by enzyme digestion and DNA sequencing. Both Western blotting and ELISA demonstrated the antigenicity of the purified mVEGFR2D1-4 fusion protein, which obviously blocked the effect of VEGF in promoting HUVEC proliferation in vitro. CONCLUSION: The mVEGFR2D1-4/GST fusion protein obtained shows a strong antigenicity and biological activity to facilitate further study of active anti-tumor immunotherapy targeting VEGFR2.

[Construction and expression of eukaryotic expression plasmid pIRES-neo-HBAg carrying HBV fusion antigen gene].

OBJECTIVE: To construct a eukaryotic expression plasmid harboring HBV fusion antigen gene, and to express it in 293T cells. METHODS: The HBV fusion gene fragment was amplified by PCR from the plasmid pVAX1-HBV containing HBV fusion gene. After purified, the product was cloned into pMD18-T vector. The recombinant plasmid was confirmed by endonuclease digestion and sequencing analysis, and then subcloned into eukaryotic expression vector pIRES-neo. Then the recombinant expression plasmid pIRES-neo-HBAg was transfered into 293T cells by Lipofectamine(TM); 2000. The expression of HBV fusion antigen was identified by Western blotting, flow cytometry and immunofluorescence cytochemistry. RESULTS: The eukaryotic expression vector pIRES-neo-HBAg was constructed successfully. The expression of fusion antigen could be detected in the pIRES-neo-HBAg transfected 293T cells by Western blotting, immunofluorescence cytochemistry and flow cytometry. CONCLUSION: The eukaryotic expression plasmid pIRES-neo-HBAg is successfully constructed and the fusion antigen is expressed in 293T cells.

[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.