ABSTRACT
Objective To construct a recombinant fusion protein with pneumococcal surface pro-tein A (PspA) of Stretococcus pneumonia (SPN) familyⅠclade 1 and 2, and to analyze the immunogenici-ty of the fusion protein.Methods The gene fragments encoding theα-helix of PspA of the two clades were amplified by PCR and then inserted into the expression vector pET-27b(+) to construct the recombinant ex-pression plasmid.The transformed Escherichia coli BL21 strains carrying expression plasmid were induced by IPTG to express the recombinant protein.The titers and affinity of antibodies against PspA protein were measured by ELISA.An opsonophagocytic assay and an animal experiment were performed to evaluate the immunogenicity of the recombinant protein.Results Double enzyme cutting and gene sequencing confirmed the two purpose gene fragments were correctly expressed in the expression vector pET-27b(+).The titers of anti-PspA antibody in the serum of Kunming ( KM) mice immunized with the fusion protein were 1 ×104 . The affinity of anti-PspA antibody reached to 2×105 .The rates of recombinant PspA6B-PspA05 protein me-diated phagocytosis for SPN6B, SPN05 and SPN01 strains were 20%, 15% and 8.8%, respectively.No SPN23F strain was engulfed by macrophages upon the stimulation with PspA6B-PspA05 protein.The survival rates of mice injected with SPN05, SPN6B, SPN01 and SPN23F strains were respectively 75%, 92%, 75%and 33%upon the immunization of PspA6B-PspA05 protein.Conclusion The recombinant fusion protein PspA6B-PspA05, constructed with the PspA proteins of Stretococcus pneumonia familyⅠclade 1 and 2, was successfully expressed in the E.coli prokaryotic system with the advantage of high immunogenicity.High ti-ters of anti-PspA antibodies with high specificity were induced in KM mice upon the stimulation with Ps-pA6B-PspA05 protein.Moreover, a cross-protective immunity was induced in KM mice upon the immuniza-tion with PspA6B-PspA05 protein.
ABSTRACT
Objective To Investigate correlation between screening assay of human papillomavirus (HPV) and microbial pathogens in gynecology. Methods Cervical samples were collected to search for HPV, bacteria and yeast infections in gynecologic outpatients. HPV typing was carried out by PCR and sequencing on cervical brush specimens. Chlamydia trachomatis was identified by strand displacement amplification (SDA) and the other microorganisms were detected by conventional methods. All data were analyzed to investigate the correlation among them. Results In this cross-sectional study, among 857 enrolled outpatients, there were 266 cases with positive HPV DNA, and the rate of infection was 31.0%(266/857). HPV genotype showed that thirty-five different HPV types were identified, of which HPV16 was the most prevalent ( 14.5%, 38/262), followed by HPV58 (9.2%, 24/262), HPV53 (8.0%, 21/262)and HPV42 (6.1%, 16/262); while other genotypes were present in less than 5% of HPV positive women.According to the reclassification, the aggregated percentage (high-risk and probably high-risk) of detected HPV was 58.8% ( 154/262), 27.9% (73/262) for low-risk and 13.4% (35/262) for unknown-risk HPV types. Among HPV positive women, cervical brush specimens results showed that more than 60% cases with normal cytology, 3.8% (10/266) with high-grade squamous intraepithelial lesions (HSIL), 29. 7% (79/266) with low-grade squamous intraepithelial lesions (LSIL) and 3.0% (8/266) with atypical squamous cells of undetermined significance (ASCUS), respectively. Statistical analyses revealed there was a significant association between the infected HPV and Chlamydia trachomatis or Ureaplasma urealyticum ( >10000 CCU/ml; all P <0.01), while no correlation was found between HPV infection and bacterial vaginosis, streptococcus agalactiae, candida, Trichomonas vaginalis or Ureaplasma urealyticum ( ≤ 10000CCU/ml; all P > 0.05 ). Among the cases with bacterial vaginosis, the positive rate of HPV infected was42.6%. Chlamydia trachomatis was one of the high-risk factors for the infection of HPV ( OR = 2.82, 95%CI: 1.74 -4.57). Mycoplasma hominis was isolated only in 2 cases, no patient was infected with Neisseria gonorrhocae. Conclusions Although bacterial vaginosis was not significantly associated with HPV, it was more common among the HPV positive women. There is the significant association between HPV and Chlamydia trachomatis or Ureaplasma urealyticum which may be increase the infection of HPV. These data suggest that it may be important to screen for the simultaneous presence of different microorganisms which may have synergistic pathological effects.