The VP1 protein of foot-and-mouth disease virus serotype A was prokaryotically expressed and purified to replace the traditional virus antigen for estab- lishing a fast, safe, effective indirect ELISA method, so as to...The VP1 protein of foot-and-mouth disease virus serotype A was prokaryotically expressed and purified to replace the traditional virus antigen for estab- lishing a fast, safe, effective indirect ELISA method, so as to detecting antibody of foot-and-mouth disease virus serotype A. Western-Blot test showed that the VP1 recombinant protein could be used as detective antigen as it can be specifically recognized by bovine positive serum of FMDV serotype A. By employing matrix titra- tion method, the optimal parameters were obtained as follows： 1 mg/L VP1 protein as coating antigen, Vserum：Vblocking solution = 1：50 dilution for serum and Vsecondary enzyme-linked antibedies：Vblocking solution ---1：2 000 for enzyme combined antibodies. The results showod that the sensitivity and specificity of this method were 94.32% and 99.09% respectively, the coefficients of variations in intra-assay and inter-assay reproducibility tests was lower than 8%. Compared with liquid phase blocking ELISA kits, the agreement of 201 serum samples reached 92.54%. The VP1-ELISA method established here is specific, sensitive, stable and simple, which can be used to monitor the antibody level of FMD serotype A.展开更多
The paper was to obtain the VP1 protein of FMDV serotype A with high activity. With recombinant plasmid pMD19A-T-vp1 as the tem- plate, vpl gene fragment amplified by PCR was connected into prokaryotic expression vect...The paper was to obtain the VP1 protein of FMDV serotype A with high activity. With recombinant plasmid pMD19A-T-vp1 as the tem- plate, vpl gene fragment amplified by PCR was connected into prokaryotic expression vector pET28a to construct recombinant plasmid pET-A-vpl. The E. coli BL21 （DE3） strain containing recombinant plasmid pET-A-vpl were induced by IPTG. SDS-PAGE showed that VP1 protein was ex- pressed in the form of inclusion body, and its molecular weight was about 29 ku. Based on the optimizing IPTG concentration and expression time, the largest expression of VP1 protein was induced by 0.3 mmol/L IPTG for 6 h at 37 ℃. Western-Blot analysis indicated that the expression of VP1 protein could be specifically recognized by positive serum of FMDV serotype A. ELISA test showed that VP1 inclusion body protein had high activity after purification by washing and renaturation by urea concentration gradient dialysis.展开更多
The researches on chlamydia in recent years show that chlamydia bacteriophage may be a potential and effective means to solve the clinical infection of chlamydia trachomatis（Ct）. We investigated the biological effec...The researches on chlamydia in recent years show that chlamydia bacteriophage may be a potential and effective means to solve the clinical infection of chlamydia trachomatis（Ct）. We investigated the biological effect of chlamydiaphage phi CPG1 capsid protein Vp1 on Ct both in Mc Coy cells and genital tract of mice. Different concentrations of Vp1 were co-incubated with Ct E serotype strain in Mc Coy cells. Female BALB/c mice were used to establish Ct E strain-induced urogenital infection model. They were randomly divided into five groups and given different treatments on the fifth day after Ct inoculation. Animals in groups 1 and 2 were given 30 μL different concentrations of Vp1 in the genital tract respectively, those in group 3 were intramuscularly injected with 30 μL Vp1, those in the infected group did not receive any intervention, and those in the control group received 30 μL PBS in the genital tract. The vaginal discharge was collected to identify the live chlamydia by cell culture and gene fragment by real time PCR different days after infection. Inhibition rate of 100 μg/m L and 50 μg/m L Vp1 proteins against Ct E strain in the Mc Coy cell cultures was 91% and 79% respectively. The number of intracellular Ct inclusion in the Mc Coy cells co-cultured with vaginal discharge of group 1 and group 2 was less than in the infected group, and that in group 1 was less than in group 2, on the 7th day after Ct inoculation. Real-time PCR showed that chlamydia concentration of the vaginal discharge in group 2 was lower than in the infected group, and that in group 1 was lower than in group 2 on the 10 th day. It was suggested that Vp1 capsid proteins had inhibitory effect on the proliferation of Ct serovar E strain in cell culture and mouse genital tract.展开更多
基金Supported by Joint Funds of the NSFC and Henan Province(U1204327)Henan Provincial Key Laboratory Construction(122300413217)
文摘The VP1 protein of foot-and-mouth disease virus serotype A was prokaryotically expressed and purified to replace the traditional virus antigen for estab- lishing a fast, safe, effective indirect ELISA method, so as to detecting antibody of foot-and-mouth disease virus serotype A. Western-Blot test showed that the VP1 recombinant protein could be used as detective antigen as it can be specifically recognized by bovine positive serum of FMDV serotype A. By employing matrix titra- tion method, the optimal parameters were obtained as follows： 1 mg/L VP1 protein as coating antigen, Vserum：Vblocking solution = 1：50 dilution for serum and Vsecondary enzyme-linked antibedies：Vblocking solution ---1：2 000 for enzyme combined antibodies. The results showod that the sensitivity and specificity of this method were 94.32% and 99.09% respectively, the coefficients of variations in intra-assay and inter-assay reproducibility tests was lower than 8%. Compared with liquid phase blocking ELISA kits, the agreement of 201 serum samples reached 92.54%. The VP1-ELISA method established here is specific, sensitive, stable and simple, which can be used to monitor the antibody level of FMD serotype A.
基金Supported by NSFC-Joint Personnel Training Fund of Henan Province(U1204327)Special Fund for Construction of Provincial Key Laboratory in Henan Province(122300413217)
文摘The paper was to obtain the VP1 protein of FMDV serotype A with high activity. With recombinant plasmid pMD19A-T-vp1 as the tem- plate, vpl gene fragment amplified by PCR was connected into prokaryotic expression vector pET28a to construct recombinant plasmid pET-A-vpl. The E. coli BL21 （DE3） strain containing recombinant plasmid pET-A-vpl were induced by IPTG. SDS-PAGE showed that VP1 protein was ex- pressed in the form of inclusion body, and its molecular weight was about 29 ku. Based on the optimizing IPTG concentration and expression time, the largest expression of VP1 protein was induced by 0.3 mmol/L IPTG for 6 h at 37 ℃. Western-Blot analysis indicated that the expression of VP1 protein could be specifically recognized by positive serum of FMDV serotype A. ELISA test showed that VP1 inclusion body protein had high activity after purification by washing and renaturation by urea concentration gradient dialysis.
基金supported by National Natural Science Foundation of China(No.31370211)
文摘The researches on chlamydia in recent years show that chlamydia bacteriophage may be a potential and effective means to solve the clinical infection of chlamydia trachomatis（Ct）. We investigated the biological effect of chlamydiaphage phi CPG1 capsid protein Vp1 on Ct both in Mc Coy cells and genital tract of mice. Different concentrations of Vp1 were co-incubated with Ct E serotype strain in Mc Coy cells. Female BALB/c mice were used to establish Ct E strain-induced urogenital infection model. They were randomly divided into five groups and given different treatments on the fifth day after Ct inoculation. Animals in groups 1 and 2 were given 30 μL different concentrations of Vp1 in the genital tract respectively, those in group 3 were intramuscularly injected with 30 μL Vp1, those in the infected group did not receive any intervention, and those in the control group received 30 μL PBS in the genital tract. The vaginal discharge was collected to identify the live chlamydia by cell culture and gene fragment by real time PCR different days after infection. Inhibition rate of 100 μg/m L and 50 μg/m L Vp1 proteins against Ct E strain in the Mc Coy cell cultures was 91% and 79% respectively. The number of intracellular Ct inclusion in the Mc Coy cells co-cultured with vaginal discharge of group 1 and group 2 was less than in the infected group, and that in group 1 was less than in group 2, on the 7th day after Ct inoculation. Real-time PCR showed that chlamydia concentration of the vaginal discharge in group 2 was lower than in the infected group, and that in group 1 was lower than in group 2 on the 10 th day. It was suggested that Vp1 capsid proteins had inhibitory effect on the proliferation of Ct serovar E strain in cell culture and mouse genital tract.
