Objective To study the effect of VacA on the secretion of THP-1 macrophages as an individual virulence determinant, and the effect of NF-kB on the secretion of THP-1 macrophages. Methods The recombinant plasmid pDsRed-Monomer-Cl/vacA was transfected into macrophages. The cytokine con-tent of TNF-α or IL-1β in the culture medium was tested quantitatively with ELISA kit, respectively. The content of NO or ROS in the culture medium was tested with Griess reagent or DCFH-DA fluorescent probe. The apoptosis rate of macrophages was tested by flow cytometry. The effect of PDTC, an inhibitor of NF-kB, on the secretion and apoptosis of macrophages transfected with the recombinant plasmids, was also studied. The activity of NF-kB was examined in THP-1 cells by electrophoretic mobility gel shift assay(EMSA). Re-suits At 6 h after transfection, the level of TNF-α and IL-1 β in macrophages transfected with the recombi-nant plasmids was significantly higher than that of the control group (P <0.05). At 6 h or 12 h after trans-fection, the level of NO and ROS in macrophages transfected with the recombinant plasmids was significantly higher than that of the control group (P <0.05). At 16 h after transfection, the apoptosis rate of macropha-ges transfected with the recombinant plasmids was significantly higher than that of the control group (P < 0.05). PDTC decreased the production of TNF-α, IL-1 β, NO, ROS and apoptosis rate induced by VacA. VacA was found to trigger NF-kB activation. Conclusion The over-expression of VacA fusion protein can up-regulate secretion and apoptosis of macrophages. Activation of NF-kB is probably involved in the produc-tion of TNF-α, IL-1β, NO, ROS and apoptosis induced by VacA.

Objective To investigate the immune response of mucosal immunization of new chitosan(CS) nanoparticles coating DNA vaccine. Methods The chitosan nanoparticles containing plasmid DNA encoding H. pylori lipoprotein Lpp20 gene were prepared using a complex coacervation method and then its speciality were analyzed. We then administered the naked plasmid DNA and chitosan-DNA nanoparticles to 6-week-old female BALB/c mice by intranasal or oral mucosal routes to observe the humoral and cellular immune responses. Results Naked plasmid pcDNA3.1 ( + )/Lpp20 and chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles both induced effective immune response in mice through mucosal vaccination. Specific IgG and sIgA antibodies of chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles groups were higher than that of naked pcDNA3.1 ( + )/Lpp20 group. The concentration of cytokines IFN-γ and IL-4 in cultural supernatant of T lymphocytes from chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles immunized mice increased greatly than that of control groups. After stimulated by corresponding antigen, the stimulation index of intranasal or oral delivery of chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles group was significantly higher than that of pcDNA3.1( + )/Lpp20 group, CS group and PBS control group. Moreover, systemic and mucosal immune responses in mice induced by intranasal immunization were stronger than that of oral immunization. Conclusion Chitosan nanoparticles enhanced the immune response of pcDNA3.1 ( + )/Lpp20 DNA vaccine by intranasal or oral administration in BALB/c mice. Compared to oral administration, intranasal delivery of chitosan-pcDNA3.1 ( + )/Lpp20 DNA nanoparticles could induce stronger cellular and humoral immune responses in BALB/c mice.

Objective To construct DNA vaccine containing MOMP gene of Chlamydia trachomatis and to observe immune response in mice. Methods Mice of 4 - 6 weeks old were immunized with pcDNA3.1-MOMP or pcDNA3.1 intramuscularly at a dose of 100 μg. Booster immunizations were employed at 2-week interval for two times. Specific antibody in the sera of mice and the level of IFN-γ in murine spleen lymphocyte supernatant were detected by ELISA. The proliferation response of spleen cells was detected by MTT assay. Results Significant specific antibody titers were observed and the highest titer was 1: 1 024 in mice after three times immunization with pcDNA3.1-MOMP. The proli-feration response of spleen cells were significantly higher than that of mice injected with pc DNA3.1. IFN-γ reached(532.0 + 45.4)pg/mL in immunized mice. Conclusion Strong responses of humoral and cellular immunity can be evoked by DNA vaccine of pcDNA3.1-MOMP in mice.

With the development of basic disciplines such as molecular biology,immunology,cell biology and so on. the pathogen biology research do not stop at the organ and cellular level,but go deep into the protein and gene level. It is a great boost to the deep studies of pathogen biology in diagnosis,treatment,pathogenesis,prevention and epidemiology.

Objective To summarize the radiography ,CT and MRI findings of maxillary arteriovenous malformation (AVM ) . Methods Seventeen patients with maxillary AVM underwent panoramic radiography (3 patients) and enhanced MRI examination (6 patients) ,all the patient underwent enhanced CT examination .The clinical manifestation and imaging findings of maxillary AVM ,in‐cluding the location ,shape ,margin ,inner texture ,involvement of adjacent structures ,the density and signal intensity of the lesions , were analyzed .Results The lesions mainly located in molar areas (15/17) .The major clinical manifestation were repeated bleeding and acute bleeding .Other symptoms included swelling of the face ,pulsatile soft mass and anesthesia .The panoramic radiography only showed increased density .According to the change of the maxilla on enhanced CT images ,the lesions could be devided into two types :type Ⅰ ,showed intraosseous osteolytic destruction and cortical expansion (n=12);type Ⅱ ,showed“ground glass”appearance (n=5) .Bone destruction and soft tissue involvement ,widened feeding artery and draining veins ,elevated maxillary sinus were shown in all patients .External jugular vein enlargement and early enhancement (n=14) and root resorption (n= 6) were also detected . Flowing void on T1 and T2 weighted images (type Ⅰ) and hypo‐or isointense on T1WI ,hyperintense on T2WI and obvious enhance‐ment after injecting contrast material (type Ⅱ ) could observed .Conclusion Enhanced CT examination could be primarily recom‐mended and observe the extent of lesions and situation of vessels invaded of maxillary AVM .

Objective To construct the recombinant plasmid containing the major outer membrane protein(MOMP) gene of Chlamydia trachomatis and expres s MOMP protein in E.coli BL21. Methods The MOMP gene was amplified by polymera se chain reaction from the genome of Chlamydia trachomatis serovar D. The amplif ied fragment was directly inserted into pUCm-T vector and verified by DNA sequen cing. MOMP gene was then subcloned into the prokaryotic expression vector pET-22 b(+). The recombinant protein of MOMP was purified by Ni-NTA affinity chromatogr aphy and identified by SDS-PAGE and Western blot. Results The MOMP gene, which is about 1 200 bp, was successfully amplified and cloned. The DNA sequence of t he cloned MOMP gene was the same as that published by the GenBank. SDS-PAGE anal ysis showed that the relative molecular weight of this fusion protein was about 47 kDa which was consistent with the theoretically predicted value, and the spec ificity of this recombinant protein was confirmed by Western blot. Conclusions The MOMP gene of Chlamydia trachomatis was successfully cloned and expressed in the prokaryotic expression system, which may lay the foundation for the developm ent of Chlamydia trachomatis vaccine.

Objective To construct an eukaryotic expression plasmid PeDNA3.1 (+)/Lpp20 and to detect its expression in HeLa cells, and to observe the humoral and cellular immune responses in C57BL/6 mice induced by the Helicobacter pylori Lpp20 DNA vaccine injected intramuscularly. Methods The Lpp20 gene was amplified by PCR. PCR product was subcloned into the eukaryotic expression vector pcDNA3.1 (+)/ Lpp20, and the recombinant plasmid was transfected into HeLa cells using Liposome. After verifying that the Lpp20 antigen gene could be expressed in HeLa cells. Six weeks old C57BL/6 mice were immunized with pcDNA3.1 (+)/Lpp20 or pcDNA3.1 (+) or PBS buffer intramuscularly at 2-week interval for four times. ELISA was used for the quantitative detection of the specific IgG antibody in the sera of C57BL/6 mice and the cytokine IFN-γ in mice spleen lymphocyte culture medium after stimulating by Lpp20. The proliferation response of spleen cells was detected by MTT assay. The Lpp20 gene in muscle was identified by PCR. Results The significant specific antibody titers were detected by ELISA in DNA vaccine groups and the highest titer was 1:1024 after 6 weeks. The cytnkine IFN-γ in mice inoculated with pcDNA3.1 (+)/Lpp20 was increased and reached (410.36±56.23) pg/ml. A significant difference was tested between the experiment group and the control group[(25.26±10.85)pg/ml] ,P <0.01. The proliferation response of spleen cells of DNA vaccine group(SI: 2.37±0.22) was significantly higher than those of mice injected with pcDNA3.1 (+) (SI:1.53+0.47) ,P<0.01. Lpp20 gene could exist constantly in musculature cells of mice. Conclusion The eukaryotic expression recombinant pcDNA3.1 (+)/Lpp20 was successfully constructed. Strong humoral and cellular im-munity can be induced by DNA vaccine of pcDNA3.1(+)/Lpp20 in C57BL/6 mice, which might be helpful for further investigation concerning the immunoprotection of DNA vaccine.

Objective:To construct NMB0315 eukaryotic expression recombinant vector ,detect specific humoral and cellular immune response induced by the recombint DNA vaccine intramuscularly in female BALB /c mice,evaluate the immunocompetence and immunoprotection of the vaccine , so as to provide experimental basis for the development of a novel nucleic acid vaccine against N.meningitidis serogroup B .Methods: The whole NMB0315 gene was amplified by PCR from the standard strains MC 58 genomic DNA,cloned into a plasmid pcDNA3.1(+),identified by double digestion of the recombinant plasmid with restriction enzymes and se -quencing.The recombinant vector pcDNA 3.1 (+)/NMB0315 was transfected into eukaryotic COS-7 cells and RAW264.7 cells, the NMB0315 protein was detected by immunocytochemical method and Western blot respectively .The levels of specific humoral and cellular immune response were detected after inoculating in female BALB /c mice intramuscularly with the recombinant plasmid .The immune protective effect was investigated with the DNA vaccine and the bactericidal titer of the immune serum was deter mined by serum bactericidal assay ( SBA ) in vitro.Results: The recombinant pcDNA3.1 (+)/NMB0315 was effectively transcripted and expressed in eukaryotic cells and the specific humoral and cellular immune responses were induced in the inoculated mice .In the re-combinant pcDNA3.1(+)/NMB0315 group ,the levels of serum IgG,IgG1,IgG2a,IgG2b and IgG3 and genital tract sIgA were significantly higher than in controls ( P<0.001 ) .The stimulation index in the culture supernatant of the spleen lymphocytes of the vaccine group was higher than that of the control group (P<0.05).The ratios of serum IgG2a/IgG1 in the DNA vaccine group were less than 1.The bactericidal titer of the NMB 0315+CpG group reached 1:128 following three immunizations , the protection rate of the vaccine group was 70%against the N.meningitidis strain MC58.Conclusion:The NMB0315 nucleic acid vaccine could induce higher levels of humoral immunity and cellular immunity and showed effective protection against N .meningitidis serogroup B , the immune serum had strong bactericidal activity in vitro .

Objective To determine the immunogenic and adhesive abilities of a segment (P1C protein) that located at the carboxy terminal region of P1 protein (1125 to 1395 amino acids).Methods A recombinant prokaryotic vector (pGEX6p-2/p1c) was constructed for P1C protein expression in E.coli BL21DE3.The expressed target recombinant protein (rP1C) was identified using SDS-PAGE and Western blot assay,and then extracted by GST-based affinity chromatography.The purified rP1C was used to immunize BALB/c mice to obtain rP1C-antiserum and titer of the antiserum was determined by ELISA.Immunoreactivity of the rP1C to the sera form M.pneumoniae-infected patients was detected using Western blot assay,while activity of the rP1C adhering to HeLa cells as well as adhesion blockage of the rP1C antiserum were detected using indirect immunofluorescence assays.Results The constructed prokaryotic expression system could efficiently express soluble rP1C with a relative molecular weight of 66×103.The antiserum from rP1Cimmunized mice showed an ELISA titer as high as 1:64 000.Both the M.pneumoniae-infected patients' sera and the mouse antiserum against rP1C could recognize as well as combine with the rP1C.rP1C could adhere to HeLa cells and the adhesion could be blocked by the mouse antiserum with an antiserum concentration-dependent manner.Conclusion P1C,a segment of M.pneumoniae P1 protein,possesses powerful immunogenicity and immunoreactivity and cell-adhered activity,indicating the protein segment can be used as an antigen candidate for developing vaccines and serological diagnostic methods of M.pneumoniae-induced diseases.

ObjectiveTo screen a 12-mer phage display peptide library by the polyclonal antibody (pAb) against the recombinant adhesion protein of Mycoplasma genitalium (rMgPa) in order to obtain the antigenic mimic epitopes of MgPa.MethodsThe purified pAb was used to screen the immunodominant mimic epitopes of MgPa by a random 12-peptide phage display library.Seventy-four recombinant phage clones were randomly selected,and then DNA sequence analysis and computer-based bioinformatics analysis were performed to define the consensus amino acid residues of the mimotopes by MIMOX.The binding specificities of the selected phage-displayed peptides to the purified pAb were confirmed by ELISA,competitive ELISA and Western blot analysis.Results After four rounds of biopanning,a significant enrichment of phages was achieved,the inserts from 74 phage clones distinguished 45 peptides based on the different amino acids sequences.Amongst 45 peptides,36 peptides were ELISA positive and 23 peptides that absorbance values were higher than 1.5 showed high reactivities with pAb and effectively inhibited the binding of pAb to rMgPa.Immunoscreening via phage display peptide library revealed three different mimptopes of adhesion protein of M.genitalium,P-S-A-A/V-X-R-F/W-E/S-L-S-P,A-K-I/L-T/Q-X-T-L-X-L and K-S-L-S-R-X-D-X-I.Results of bioinformatics analysis by MIMOX demonstrated that S,A,F for cluster 1,A,K,I,T and L for cluster 2,K,S,L,R,D and I for cluster 3,may be the key consensus amino acid residues in the aligned mimotopes,respectively.ConclusionAntigenic mimics on MgPa were successfully identified and the motif P-S-A-A/V-X-R-F/W-E/S-L-S-P,A-K-I/L-T/Q-X-T-L-X-L and K-S-L-S-R-X-D-X-I may represent the immunodominant mimic epitopes of MgPa.And S,A,F K,I,T,L,R and D may be the key amino acid residues for the epitopes of MgPa.