Identification and characterization of a Streptococcus suis immunogenic ornithine carbamoytransferase involved in bacterial adherence.

BACKGROUND: Streptococcus suis (SS) is a major swine pathogen and a serious zoonotic pathogen causing septicemia and meningitis in piglets and humans. Using an immunoproteomic approach, we previously brought evidence that ornithine carbamoytransferase (OCT) may represent a vaccine candidate to protect against S. suis biofilm-related and acute infections. METHOD: In this study, the gene encoding OCT was cloned into the expression vector pET-28a and the recombinant protein was expressed in Escherichia coli BL21. The immunogenicity and protective efficacy of the SS OCT was further investigated in a mouse model. RESULTS: The protein was found to be expressed in vivo and elicited high antibody titers following SS infections in mice. An animal challenge experiment with SS showed that 62.5% of mice immunized with the OCT protein were protected. Using an in vitro competitive adherence inhibition assay of adherence, evidence was obtained that OCT could significantly reduce the number of SS cells adhered to porcine kidney PK-15 cells. The bacterial levels recovered in mice of the OCT immunized group were significantly decreased in some organs, compared with the control group. CONCLUSION: In summary, our results suggest that the recombinant SS OCT protein, which is involved in bacterial adherence, may efficiently stimulate an immune response conferring protection against SS infections. It may therefore be considered as a potential vaccine candidate, although further studies are necessary to evaluate their use in swine.

The preventive effects of hyperoside on lung cancer in vitro by inducing apoptosis and inhibiting proliferation through Caspase-3 and P53 signaling pathway.

Though advanced surgical operation and chemotherapy have been under taken, lung cancer remains one of the most aggressive and fatal human malignancies with a low survival rate. Thus, novel therapeutic strategies for prevention and remedy are urgently needed in lung cancer. Hyperoside, known as quercetin-3-O-ß-d-galactopyranoside, is a natural flavonol glycoside discovered in plants of genera Hypericum, displaying anti-oxidant, anticancer, and anti-inflammatory properties. In the study, we attempted to investigate whether hyperoside could inhibit lung cancer progression via Caspase-3- and P53-regulated cell death. In in vitro and in vivo experiments, we explored hyperoside at three different dosages on cell apoptosis, cell proliferation, cell migration, cell invasion, cell cycle distribution, the related signalling pathways, as well as xenograft tumor growth. Our data suggested that hyperoside exerted inhibitory role in lung cancer development. Inhibition of NF-κB transcriptional activity, Caspase-9/Caspase-3 activation, the cell cycle arrest, and suppression of cell proliferation-related signaling pathway led to the lung cancer inhibition. Further, via mice xenograft model in vivo, we indicated that hyperoside completely impeded tumor growth through angiogenesis inhibition. Our study illustrated that hyperoside might provide a synergistic anticancer effects that warrant further study and investigation due to its potential role in clinical applications.

[Association between interleukin-1B polymorphisms and chronic obstructive pulmonary disease: a meta-analysis].

OBJECTIVE: To explore the association between the -511C/T, -31T/C and +3954C/T polymorphisms of interleukin-1B (IL-1B) gene and chronic obstructive pulmonary disease (COPD) using the method of meta-analysis. METHODS: Comprehensive searches were performed of PubMed, Embase, Ovid, Wanfang and Chinese journal full-text database to retrieve the related case-control studies. The pooled odds ratios were performed respectively for allele comparison, additive genetic model, dominant genetic model and recessive genetic model and subgroup analysis was also performed by ethnicity. RESULTS: Seven case-control studies were included for meta-analysis. Pooled analysis showed that neither -511C/T, -31T/C nor +3954 C/T polymorphisms increased the susceptibility to COPD. In the subgroup analysis by ethnicity, significant risks were found in the Caucasian population for -511C/T T allele (OR = 1.76, 95%CI 1.22 - 2.54, P = 0.002), but not in the Asian population (OR = 0.94, 95%CI 0.64 - 1.38, P = 0.736). Significant risks were also found in the Caucasian population for -31T/C C allele (OR = 0.62, 95%CI 0.40 - 0.97, P = 0.035), but not in the Asian population (OR = 1.06, 95%CI 0.89 - 1.26, P = 0.533). CONCLUSIONS: IL-1B polymorphisms may play a role in the susceptibility of COPD in an ethnicity-specific manner. In the Caucasian population, the risk of COPD was associated positively with the IL-1B -511C/T T allele and negatively with the IL-1B -31T/C C allele.

Chronic obstructive pulmonary disease assessment test score correlated with dyspnea score in a large sample of Chinese patients.

BACKGROUND: The chronic obstructive pulmonary disease assessment test (CAT) is an easy to use health-related quality of life questionnaire, the modified Medical Research Council (mMRC) dyspnea scale is a classic dyspnea scale which is widely used, while the correlation between them is still not clear. This study investigated the use of the Chinese translation of CAT in chronic obstructive pulmonary disease patients and its correlation with the mMRC dyspnea scale. METHODS: The multicenter cross-sectional study was conducted in 329 hospitals throughout China from March 1 to April 30, 2010. Chronic obstructive pulmonary disease patients completed both the assessment test and the dyspnea scale during a single study visit. RESULTS: Six thousand, four hundred and thirty-seven patients were evaluated; 74.9% were male and the mean age was (64.9 ± 10.0) years. Median test scores in dyspnea grades 0 to 4 were 14, 16, 22, 26 and 32, respectively; these differences were statistically significant. The CAT score was moderately correlated with mMRC dyspnea grade (r = 0.579, P < 0.001). There was no significant difference in mean CAT score between males and females, and patients of high and low socioeconomic status. Primary analysis suggested that CAT scores were higher in older patients (>65 years) than in younger patients (≤ 65 years) and increased with duration of formal education, but these findings were repudiated by further analysis of subgroups according to mMRC dyspnea grade. CONCLUSIONS: There was no obvious confounding factor influencing use of the CAT in Chinese patients. CAT scores were moderately correlated with the mMRC dyspnea scale.

Expression, refolding, and characterization of human soluble BAFF synthesized in Escherichia coli.

The B lymphocyte stimulator (BAFF) is a novel member of the tumor necrosis factor (TNF) ligand family which is important in B lymphocyte maturation and survival. Here, a recombinant form of the extracellular domain of the BAFF (hsBAFF) was expressed in Escherichia coli BL21(DE3) under the control of a T7 promoter. The resulting insoluble bodies were separated from cellular debris by centrifugation and solubilized with 8 M urea. A rapid and simple on-column refolding procedure was developed. It was applied and then the refolded hsBAFF was purified by anion-exchange. The purified final product was >98% pure by SDS-PAGE stained with Coomassie brilliant blue R-250. Mass spectroscopic analysis indicated the protein to be 17.5 kDa, which equalled the theoretically expected mass. The N-terminal sequencing of refolding hsBAFF showed the sequence corresponded to the designed protein. The correct refolding of the recombinant protein was verified in the recovery of its secondary and tertiary structures as assessed by circular dichroism and fluorescence emission spectra. The renatured protein displayed its immunoreactivity with the antibodies to BAFF protein by Western blotting. The final purified material was biologically active in a validated induced human B lymphocyte proliferation bioassay. The expression and in vitro refolding of hsBAFF resulted in production of an active molecule in a yield of 15 mg/L flask cultivation.