Objective To construct the eukaryotic expression plasmids of Mycobacterium tuberculosis ESAT-6 antigen and to investigate its immunogenicity in mice. Methods The sequence encoding ESAT-6 was amplified by PCR from Mycobacterium tuberculosis H37Rv genomic DNA. Then, the amplified fragment was sub-cloned into pVAC expression vector. The eukaryotic expression plasmid pVAC-ESAT-6 was transfected into Vero E6 cells with liposome. The mRNA expression of pVAC-esat-6 in Vero E6 cells was detected by RT-PCR and its expression product was analyzed by Western-blot. The plasmid pVAC-esat-6 was introduced into the mice by gene gun injection. The specific antibody to ESAT-6 and the level of IFN-? in supernatant of spleno-lymphocyte cultures were detected by ELISA methods. Results The recombinant plasmid pVAC-esat-6 was successfully constructed, and the expression of ESAT-6 was also detected in vitro. After vaccinated three times, the mice produced specific antibody and the level of IFN-? in supernatant of spleno-lymphocyte cultures in group of pVAC-esat-6 was significantly higher than group of vector alone (P

Objective To explore the relationship of the K121Q polymorphism of membrane glycoprotein PC-1 gene with the features of insulin resistance(IR) and type 2 diabetes mellitus(T2DM).Methods The K121Q polymorphism in exon 4 of PC-1 gene were determined with the technique of polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) in 133 patients with T2DM and 108 controls with normal glucose tolerance(NGT) in Shenzhen city.The clinical and laboratory data were also compared between type 2 diabetic patients with different genotypes.Results No statistically significant differences were observed in the genotype and allele frequencies between the control and the T2DM subjects.The concentrations of fasting plasma glucose(FPG),triglycerides(TG) and C-peptide were higher in T2DM patients with KQ genotype than with KK genotype(P

The immune effect of two recombinant protein fragments of spike protein in severe acute respiratory syndrome coronavirus (SARS CoV) was investigated in Balb/c mice. Two partial spike gene fragments S1 (322 1464 bp) and S2 (2170 2814 bp) of SARS coronavirus were amplified by RT-PCR, and cloned into pET-23a prokaryotic expression vector, then transformed into competent Escherichia E. coli BL21 (DE3)(pLysS) respectively. Recombinant proteins were expressed and purified by Ni2+ immobilized metal ion affinity chromatography. The purified proteins mixed with complete Freund adjuvant were injected into Balb/c mice three times at a two-week interval. High titer antibody was detected in the serum of immunized Balb/c mice, and mice immunized with S1 protein produced high titer IgG1, IgG2a, IgG2b and IgG3, while those immunized with S2 protein produced high titer IgG1, IgG2a, but lower titer IgG2b and IgG3. Serum IFN-concentration was increased significantly but the concentrations of Il-2, IL-4 and IL-10 had no significant change. And a marked increase was observed in the number of spleen CD8+ T cells. The results showed that recombinant proteins of SARS coronavirus spike protein induced hormonal and cellular immune response in Balb/c mice.

To construct a recombinant plasmid Pet23a-M, the gene encoding severe acute respiratory syndrome (SARS) coronavirus membrane protein was amplified by RT-PCR and cloned into the expression plasmid Pet23a. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis revealed that the cloned DNA sequence was the same as that reported. The recombinants were transformed into Escherichia coli (E. Coli) BL21 (DE3) and induced by Isopropyl-beta-D-thiogalactopyranoside (IPTG). The expression of 27 kD (1 kD=0.992 1 ku) protein was detected by SDS-PAGE and pured by metal chelated chromatography. Results of Western-blot showed that this expressed protein could react with antibodies in sera of SARS patients during convalescence. This provided the basis for the further study on SARS virus vaccine and diagnostic agents.
Cloning, Molecular ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Membrane Proteins/*biosynthesis ; Membrane Proteins/genetics ; Membrane Proteins/isolation & purification ; Plasmids/biosynthesis ; Plasmids/genetics ; Recombinant Proteins/biosynthesis ; Recombinant Proteins/genetics ; Recombinant Proteins/isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus/chemistry ; SARS Virus/*genetics ; Viral Vaccines/biosynthesis

The immune effect of two recombinant protein fragments of spike protein in severe acute respiratory syndrome coronavirus (SARS CoV) was investigated in Balb/c mice. Two partial spike gene fragments S1 (322-1464 bp) and S2 (2170-2814 bp) of SARS coronavirus were amplified by RT-PCR, and cloned into pET-23a prokaryotic expression vector, then transformed into competent Escherichia E.coli BL21 (DE3)(pLysS) respectively. Recombinant proteins were expressed and purified by Ni2+ immobilized metal ion affinity chromatography. The purified proteins mixed with complete Freund adjuvant were injected into Balb/c mice three times at a two-week interval. High titer antibody was detected in the serum of immunized Balb/c mice, and mice immunized with S1 protein produced high titer IgG1, IgG2a, IgG2b and IgG3, while those immunized with S2 protein produced high titer IgG1, IgG2a, but lower titer IgG2b and IgG3. Serum IFN-γ concentration was increased significantly but the concentrations of IL-2, IL-4 and IL-10 had no significant change. And a marked increase was observed in the number of spleen CD8+ T cells. The results showed that recombinant proteins of SARS coronavirns spike protein induced hormonal and cellular immune response in Balb/c mice.

Objective To construct a prokaryotic expression system containing the dense granule protein 4(GRA4) of Toxoplasma gondii,purify the expressed protein and detect its immunogenicity.Methods The specific fragment of GRA4 gene was amplified by PCR.After subcloning the prokaryotic expression recombinant pET,GRA4,the expressed product was purified with His?BindTM affinity chromatography and analyzed by Western blot.BALB/c mice were immunized with the GRA4 recombinant protein,and the antibody IgG titer was detected by ELISA.Results The pET,GRA4 prokaryotic expression system was obtained.The MW of the expressed protein was Mr 40 000 and formed in inclusion body.After purification,the recombinant protein could be specifically recognized by the T.gondii infected rabbit serum.Mice immunized with the purified recombinant protein elicited high titer of IgG antibody.Conclusion The pET,GRA4 recombinant protein was successfully expressed and purified,which shows the immunogenicity.

To construct a recombinant plasmid Pet23a-M, the gene encoding severe acute respiratory syndrome (SARS) coronavirus membrane protein was amplified by RT-PCR and cloned into the expression plasmid Pet23a. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis revealed that the cloned DNA sequence was the same as that reported. The recombinants were transformed into Escherichia coli (E. Coli) BL21 (DE3) and induced by Isopropyl-beta-D-thiogalactopyranoside (IPTG). The expression of 27 kD (1 kD=0.992 1 ku) protein was detected by SDS-PAGE and pured by metal chelated chromatography. Results of Western-blot showed that this expressed protein could react with antibodies in sera of SARS patients during convalescence. This provided the basis for the further study on SARS virus vaccine and diagnostic agents.
Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Humans ; Membrane Proteins ; biosynthesis ; genetics ; isolation & purification ; Plasmids ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; chemistry ; genetics ; Viral Vaccines ; biosynthesis

Objective:To establish an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for plasma caffeine concentration detection, and to explore the clinical value of caffeine therapeutic drug monitoring (TDM) in the treatment of premature infants with respiratory distress syndrome (RDS).Method:Take the plasma sample in a centrifuge tube, add the caffeine deuterated isotope internal standard, then add the protein precipitant, vortex the mixture thoroughly, and centrifuge the supernatant to enter the mass spectrometry analysis. The mobile phase were methanol and water, gradient elution; the column temperature was 45 ℃, the method was established using Shimadzu LC-30AD-CL liquid system and AB SCIEX 4500 QTRAP mass spectrometer, and the sensitivity, specificity, linearity, accuracy imprecision, matrix effect, and carry-over of the method were evaluated. Sample from 30 patients diagnosed with neonatal RSD were collected in the Department of Neonatology of Renmin Hospital of Wuhan University from February to April 2021, then detected the trough concentration of caffeine in premature infants with RDS after taking the same dose of caffeine to assess the impact of individual variation on caffeine drug concentration.Results:The detection limit of caffeine was 0.02 μg/ml, and the lowest limit of quantification was 0.05 μg/ml. It showed good linearity ( R2=0.9986, R>0.99) in the concentration range from 1.0 to 100.0 μg/ml, specificity (recovery rate of 85.52%-114.12%), accuracy (recovery rate 85.97%-114.53%), intra-day and inter-day imprecision ( CV 6.01%-11.28%), matrix effects and carryover pollution were negligible. The trough concentration of 30 preterm infants with RSD after taking the same dose of caffeine (10 mg/kg) was (25.45±11.61) μg/ml, and the coefficient of variation was 44.88%. Conclusion:This study established an accurate and reliable UPLC-MS/MS method with low sample consumption to monitor the blood concentration of caffeine; caffeine TDM has certain clinical application value, which can be used to assist RDS diagnosis and treatment and improve the efficacy of caffeine.