Effect of myricetinon enterovirus 71 infection in vitro / 中国药理学通报

Aim To investigate the antiviral activity and mechanism of myricetin against enterovirus 71 (E V 7 1) infection. Methods The cytopathic effect (CPE) and plaque assay were used to observe the antiviral effect of myricetin against EV71 in Vero cell. The cells were treated with myricetin at different concentrations combined with crystal violet staining to detectthe cytotoxicity of myricetin. The effect of myricetin on VP1 protein expression was detected by Western blot. The effect of myricetin on VP1 gene expressionwas evaluated byRT-PCR. Results Myricetin pretreatment at 2. 5-20 fimol L-1' significantly inhibitedcell death induced by EV71 infection in a dose-dependent manner with the IC50 value of 5. 6 jxmol • L-1. Compared to virus control group, myricetin could significantly reduce the viral titer at the concentration of 2. 5 ~ 20 u,mol • L-1. The results of Western blot and RT-PCR showed that myricetin could markedlyreduce the gene and protein expression levels of viral capsid protein VP1. Conclusion Myricetin has significant antiEV71 activity in vitro.

Cloning, expressing and identifying of IN5 part of chlamydiaphage phiCPG1 capsid protein Vp1 protein and its inhibitory effect on the Chlamydia trachomatis / 中华临床感染病杂志

Objective To investigate the inhibitory effect of IN5 from chlamydiaphage phiCPG1 capsid protein Vp1 on Chlamydia trachomatis (Ct).Methods PCR was used to amplify IN5 gene from Vp1 DNA of phiCPG1, then the recombinant plasmid pET28a/IN5 was constructed.After transformation, the fusion protein IN5 was induced,identified and purified.Ct was incubated with the purified IN5 protein or Vp1 protein.After 48 h of incubation, the inclusion bodies were counted with iodine staining and indirect immunofluorescence.One-way ANOVA was used to compare the difference of inclusion bodies among groups.If the difference among the groups was statistically significant, the Bonferroni method was used to compare any two mean values.Finally, the inhibitory rate of IN5 protein and Vp1 protein to Ct was calculated.Results IN5 protein from chlamydiaphage phiCPG1 capsid protein Vp1 was successfully obtained.At the same concentration of 53μg/mL,the inhibitory rates of Ct growth in IN5 and in Vp1 groups were 52.42% and 78.04%, respectively.Conclusion IN5 protein has inhibitory effect on the growth of Ct,but the inhibitory rate is lower than that of Vp1, which provides a preliminary clue for searching the dominant region of Vp1 protein inhibiting the growth of Ct.

Biological Effects of Chlamydiaphage phiCPG1 Capsid Protein Vp1 on Chlamydia Trachomatis In Vitro and In Vivo / 华中科技大学学报（医学）（英德文版）

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 phiCPG1 capsid protein Vp1 on Ct both in McCoy cells and genital tract of mice.Different concentrations of Vp1 were co-incubated with Ct E serotype strain in McCoy 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/mL and 50 μg/mL Vpl proteins against Ct E strain in the McCoy cell cultures was 91％ and 79％ respectively,The number of intracellular Ct inclusion in the McCoy 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 10th 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.

Design and immunogenicity evaluation for the bacteria-like particle vaccine against swine type O foot-and-mouth disease virus / 生物工程学报

Based on gram positive enhancer matrix displaying technology, we designed and evaluated a bacteria-like particle vaccine against swine type O Foot-and-mouth disease virus. Three optimized genes of type O Foot-and-mouth disease virus strain Mya98 were cloned into recombinant prokaryotic expression vector pQZ-PA and renamed as pQZ-BT1B-PA, pQZ-BT2B-PA and pQZ-B (T1BT2) 4B-PA, fused with an anchor protein (PA) binding to Gram-positive enhancer matrix (GEM) particles specifically. The protein expression was identified with SDS-PAGE and Western blotting, and then purified with GEM particles. Five-week old female mice were randomly divided into six groups and all the immunization was developed according to subcutaneous injection. Mice in the first three groups were injected with 50 μg/dose GEM-BT1B, GEM-BT2B and GEM-B (T1BT2) 4B, respectively. Mice in the fourth group were immunized with commercial peptide vaccine as positive control. The fifth group vaccinated with host E. coli transformed with pQZ-PA fulfilled as negative control. Mice in the last group injected with sterile PBS served as blank control. The humoral immunity of recombinant protein vaccine was evaluated with peptide-specific antibody and LPB antibody. The cellular immunity was evaluated with lymphocyte proliferation test and cytokine expression detection. SDS-PAGE and Western blotting showed that the most part of soluble target fusion protein have been purified and displayed on GEM particles. Vaccine GEM-B (T1BT2) 4B stimulated mice produce not only higher level of specific antibody against peptide and Foot-and-mouth disease virus specific liquid phase blocking antibody, but also more vigorous spleen lymph proliferation and higher levels of Th1 type cytokines. To summarize, vaccine of GEM-B (T1BT2) 4B possessed good immunogenicity and opened a new way for further Foot-and-mouth disease virus subunit vaccine design.

Establishment of chemiluminescent enzyme immunoassay for detecting antibodies against foot-and-mouth disease virus serotype O in swine / 生物工程学报

Recombinant structural protein VP1 of foot-and-mouth disease virus serotype O was expressed in Escherichia coli and then purified using Nickel affinity chromatography. A chemiluminescent enzyme immunoassay (CLEIA) method was established using the purified recombinant protein as coating antigen to detect antibody of foot-and-mouth disease virus serotype O in swine. The specificity of VP1-CLEIA method is 100%. The coefficients of variation in the plate and between plates are 1.10%-6.70% and 0.66%-4.80%, respectively. Comparing with the commercial indirect ELISA kit or liquid phase block ELISA kit, the calculated coincidence rate is 93.50% or 94.00%. The high specificity and stability suggested this detection method can be used to monitor the antibody level of foot-and-mouth disease virus serotype O in swine.

Bioinformatics analysis of VP1 protein of coxsackievirus A6 / 中国免疫学杂志

Objective:To predict the basic physicochemical properties ,structure and function ,and linear B-cell epitopes of the capsid protein VP1 of coxsackievirus A6(CVA6).Methods: The amino acid sequence of the CVA6 VP1 was analyzed using Bioedit software and various online tools including SubLoc ,TargetP and the others from ExPASy Bioinformatics Resource Portal.Results: The CVA6 VP1 protein was a hydrophilic protein with a relative molecular weight of 33.6 kD and an isoelectric point of 7.92.This protein containsed 24 phosphorylation sites , but no signal peptide , transmembrane domains and possible fatty acylation sites.Its secondary structure was characterized by the richest random coils , and 48.52 percent of its amino acid residues exposed at the solution inter-face.Epitope prediction by Bepipred showed a number of potential B cell epitopes in the protein ,the highest antigenicity index among them located in the region of amino acids residue 155-165.Conclusion:The basic physicochemical properties ,structure and function characteristics ,and potential linear B-cell epitopes of CVA 6 VP1 were successfully predicted , which laid foundations for the further study on the protein and the preparation of vaccines and immunological diagnostic reagents for CVA 6 infection.

Polyclonal antibody specific for hypervariable region of VP1 capsid protein of Taura syndrome virus (TSV) prepartion and characteristic analysis / 中国免疫学杂志

Objective:Preparation and immune characteristic analysis of polyclonal antibody against hypervariable region protein of Taura syndrome virus major capsid protein VP 1 as a reference for studies on immunological diagnosis reagent.Methods:The recombinant vector pET-VP1 was transformed into E.coli BL21 for protein expression.Immunizing a New Zealand rabbit with purified VP1 protein,the titer of anti-VP1 serum was determined by Agar diffusion test and ELISA.Monoclonal phage specific binding to the purified VP1 protein was used for competitive inhibition test.Results: The VP1 protein was soluble and high expression in E.coli BL21.The biological activity titer of anti-VP1 serum reached 1∶26 ,1∶217 determined by Agar diffusion test and ELISA respectively.A litter binding activity of antiserum and VP 1 protein could be blocked by monoclonal phage , but would not affect the final positive result.Conclusion:High titer antibody Preparation of the VP 1 hypervariable region protein.The binding activity of the polyclonal antibody with VP1 protein was not affected by the mutations of VP 1 protein in minority areas ,so the antiserum could be used as immu-nological detection diagnosis agent.

A RT-PCR method for selective amplification and phenotypic characterization of all three serotypes of Sabin-related polioviruses from viral mixtures

Outbreaks caused by vaccine-derived polioviruses are challenging the final eradication of paralytic poliomyelitis. Therefore, the surveillance of the acute flaccid paralysis cases based on poliovirus isolation and characterization remains an essential activity. Due to the use of trivalent oral poliovirus vaccine (OPV), mixtures containing more than one serotype of Sabin-related polioviruses are frequently isolated from clinical samples. Because each poliovirus isolate needs to be individually analyzed, we designed polymerase chain reaction primers that can selectively distinguish and amplify a genomic segment of the three Sabin-related poliovirus serotypes present in mixtures, thus, optimizing the diagnosis and providing prompt information to support epidemiologic actions.

The effect of chlamydiaphage phiCPG1 capsid protein Vp1 on the Chlamydia trachomatis / 中华微生物学和免疫学杂志

Objective To investigate the effect of recombinant chlamydiaphage phiCPG1 capsid protein Vp1 on Chlamydia trachomatis(Ct) after Vp1 was co-cultured with Ct (reference strains and clinical strains).Methods The recombinant chlamydiaphage phiCPG1 capsid protein Vp1 was expressed and purified.Equal amount of Ct standard strains (E/UW-5/Cx and D/UW-3/Cx) or clinical strains,which had been incubated with Vp1 protein at the concentration of 53 μg/ml for 3 h at room temperature,were inoculated into McCoy.After cell culture,idione stain and transmission electron microscope were used to observe the effect of Vp1 on the Ct.The effect of Vp1 protein on the cell line McCoy was determined by MTT assay,the responses of Escherichia coli BL21 and DH5α toward Vp1 protein were determined using broth microdilution assays.Results Vp1 had obviously inhibitive effect on Ct,the inhibition ratios were about 40％-70％in clinical strains,72％ in reference strain D and 78％ in E,respectively.Abnormally enlarged RBs were observed after Vp1-treatment and Vp1 could arrest chlamydial developmental cycle using electron microscope.There was no effect of Vp1 on McCoy cells or bacteria BL21 or DH5α.Conclusion The recombinant Vp1 from phiCPG1 has obviously inhibitive effect on the growth of Ct,it will be helpful for the treatment of Ct infection in clinic.

Detection of Chlamydia trachomatis phage Vp1 gene in clinical swab specimens as well as anti-Vp1 antibodies in serum specimens / 中华皮肤科杂志

Objective To detect Chlamydia trachomatis phage Vp1 gene in clinical swab specimens and anti-Vp1 antibodies in serum specimens.MethodsCervical and urethral swab as well as serum specimens were collected from attendees to the sexually transmitted disease(STD) clinic in the Tianjin Institute of STD,during March 2008 to March 2011.PCR was conducted to detect chlamydial phage Vp1 gene in swab samples,enzyme linked immunosorbent assay(ELISA) and Western blot to detect anti-Vp1 antibody in sera.The swab specimens positive for Vp1 gene were subjected to cell culture followed by the detection of Vp1 protein with an immunofluorescence-based method.ResultsTotally,36 out of 1542 swab specimens turned out to be positive for Vp1 gene,and 23 out of 453 serum specimens for anti-Vp1 antibody.No positive results were obtained in the Vp1 gene-positive swab specimens by cell culture and immunofluorescence-based assay.ConclusionThe Vp1 gene of Chlamydial trachomatis phage and anti-Vp1 antibody are successfully detected from clinical swab and serum specimens respectively.

Genetic Analysis of the P1 Region of Human Enterovirus 71 Strains and Expression of the 55 F StrainVP1 Protein / 中国病毒学·英文版

Enterovirus 71 (EV71) is a member of the Entero-virus genus of the Picornaviridae family and is the major cause of Hand,foot,and mouth disease (HFMD) in children.Different strains from Gansu were cloned and the P1 protein was sequenced and analysed.Results indicate that there are three kinds of EV71 infections prevalent in Gansu.The VP1 protein from one of these strains,55F,was expressed.The recombinant protein was expressed with high level and reacted specifically with the EV71 patient antibody,the recombinant protein was also applied to raise antiserum in rabbits and after the fourth injection a high titer of antiserum was detected by ELISA assay.These data are useful for further clarification of prevalent EV71 strains in the north of China at the molecular level and provide a basis for EV71 diagnosis.

Molecular characterization of a 13-amino acid deletion in VP1 (1D) protein and novel amino acid substitutions in 3D polymerase protein of foot and mouth disease virus subtype A/Iran87

The nucleotide sequence of the VP1 (1D) and partial 3D polymerase (3Dpol) coding regions of the foot and mouth disease virus (FMDV) vaccine strain A/Iran87, a highly passaged isolate (~150 passages), was determined and aligned with previously published FMDV serotype A sequences. Overall analysis of the amino acid substitutions revealed that the partial 3Dpol coding region contained four amino acid alterations. Amino acid sequence comparison of the VP1 coding region of the field isolates revealed deletions in the highly passaged Iranian isolate (A/Iran87). The prominent G-H loop of the FMDV VP1 protein contains the conserved arginine-glycine-aspartic acid (RGD) tripeptide, which is a well-known ligand for a specific cell surface integrin. Despite losing the RGD sequence of the VP1 protein and an Asp26-->Glu substitution in a beta sheet located within a small groove of the 3Dpol protein, the virus grew in BHK 21 suspension cell cultures. Since this strain has been used as a vaccine strain, it may be inferred that the RGD deletion has no critical role in virus attachment to the cell during the initiation of infection. It is probable that this FMDV subtype can utilize other pathways for cell attachment.

Preparation of the Coxsackievirus A16 VP1 subunit vaccine and detection of its immunogenicity / 中华微生物学和免疫学杂志

Objective To prepare VP1 protein vaccine of Coxsackievirus A16(CA16) and evalu-ate immunngenicity the subunit vaccines of Coxsackievirus (VP1), and to establish foundation for studying CA16 vaccine. Methods CA16 VP1 was amplified by RT-PCR and cloned into pFastBac HT A plasmid, recombinated with Bacmid DNA by transposition reaction and then transfected Sf9 cell, mixed with adjuvant AI(OH)_3. After immunization BALB/c mice, evaluating immune effectiveness after booster injections 2 weeks. Results The expressed protein was analyzed by SDS-PAGE and Western blot, mice immunized with CA16 (VP1) both induced specific IgG antibody and neutralization antibody. The best immunization antigen was 20 μg, IgG antibody was 1: 1600, neutralization antibody was 1:250, typical Th1/Th2 immune response was determined by lymphocyte proliferation assay and cytokine analysis. Conclusion The CA16 VP1 gene was cloned successfully and expressed in Sf9 insect cells, CA16 VP1 protein vaccine induced both humoral and cellular immune response, to lay solid foundation for further study on CA16 vaccine.

Application of VP1 Protein to Develop Monoclonal Antibody against Foot-and-mouth Disease Virus Asial Type / 中国病毒学·英文版

In order to develop an anti-FMDV Asial type monoclonal antibody (mAb), BABL/c mice were immunized with recombinant FMDV VP1 protein. Three mAbs, 1B8, 5E1 and 5E2, were then further optimized. The result indicated that prepared anti-FMDV Asial mAbs had no cross-reactivity with Swine vesicular disease (SVD) and FMDV O, A and C type antigen. Their titers in abdomen liquor were l:5×106, l:2×106 and l:5×l06, respectively. 1B8 was found to be of IgGi subtype, 5E1 and 5E2 belonged to IgG2b subtype. In this study, the prepared mAbs are specific for detecting FMDV type Asial, and is potentially useful for pen-side diagnosis.

Expression and verification of VP1 protein of human parvovirus B19-XA strain in E. coli / 医学研究生学报

Objective: To construct a recombinant expression vector containing the VP1 whole gene of human parvovirus(HPV) B19-XA strain by DNA recombinant technology and to induce the expression of the VP1 fusion protein in E.coli.Methods: The gene of interest was amplified by PCR from the viral DNA genome extracted from the patient infected with B19 virus,and inserted into the pET28(a) expression vector.The positive recombinants pET28(a)-VP1 were transformed into E.coli BL21(DE3),and then the VP1 proteins were expressed after induced by IPTG and analyzed by SDS-PAGE and immunoblotting.In addition,rabbits were immunized with the recombinant VP1 fusion proteins as antibodies,and their valence was detected by ELISA.Results: The positive bacteria strains containing the recombinant expressive vector pET28(a)-VP1 were constructed successfully,and IPTG induced a high expression of the VP1 fusion proteins.The valence of multiclone antibodies of anti-VP1 proteins was 1∶12 800.Conclusion: The VP1 fusion proteins of the HPV B19-XA strain can be expressed efficiently in E.coli,and these proteins possess satisfactory immunogenicity and play an important role in the preparation of diagnostic reagents and the development of vaccines.

Cloning, expression and identification of chlamydial GPIC capsid Vpl protein / 中华皮肤科杂志

Objective To clone, express, and identify chlamydial GPIC capsid Vpl gene and pro- tein. Methods The complete sequence of Vp1 gene from?CPG1 phage was amplified. The amplicor was cut by restriction endonuclease, linked to plasmid vector, and transformed into E. coli.The expressed pro- tein of recombinant Vp1 was purified and identified. Results The recombinant 1 661 bp gene was se- quenced and proved to be?CPG1 Vp1 by searching Genebank. A 62 kDa capsid protein was expressed and confirmed by SDS-PAGE and Western blot. Conclusion The recombinant Vp1 seems to be a highly con- served and specific marker for chlamydial phage.