Expression of Helicobacter pylori hspA Gene in Lactococcus lactis NICE System and Experimental Study on Its Immunoreactivity.

Aim. The aim of this study was to develop an oral Lactococcus lactis (L. lactis) vaccine against Helicobacter pylori (H. pylori). Methods. After L. lactis NZ3900/pNZ8110-hspA was constructed, growth curves were plotted to study whether the growth of recombinant L. lactis was affected after hspA was cloned into L. lactis and whether the growth of empty bacteria, empty plasmid bacteria, and recombinant L. lactis was affected by different concentrations of Nisin; SDS-PAGE and Western blot were adopted, respectively, to detect the HspA expressed by recombinant L. lactis and its immunoreactivity. Results. There was no effect observed from the growth curve after exogenous gene hspA was cloned into L. lactis NZ3900; different concentrations of Nisin did not affect the growth of NZ3900 and NZ3900/pNZ8110, while different concentrations of Nisin inhibited the growth of NZ3900/pNZ8110-hspA except 10 ng/mL Nisin. No HspA strip was observed from SDS-PAGE. Western blot analysis showed that HspA expressed by recombinant bacteria had favorable immunoreactivity. Conclusion. The growth of recombinant L. lactis was suppressed even though a small amount of HspA had been induced to express. Therefore recombinant L. lactis only express HspA which was not suitable to be oral vaccine against Helicobacter pylori.

CYP3A5 ∗ 3 genetic polymorphism is associated with childhood acute lymphoblastic leukemia risk: A meta-analysis.

BACKGROUND: Several studies have investigated the association between CYP3A5 FNx01 3 genetic polymorphism and acute lymphoblastic leukemia (ALL) risk in children, but have yielded controversial results. Therefore, we performed a meta-analysis to evaluate synthetically the effect of CYP3A5 FNx01 3 polymorphism on the risk of ALL in children. METHODS: Case-control studies investigating the relationship between CYP3A5 FNx01 3 genetic polymorphism and ALL risk in children were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of association between CYP3A5 FNx01 3 polymorphism and ALL risk in children. Q-statistic test was used to evaluate the heterogeneity and publication bias was assessed through funnel plot. RESULTS: In total, five case-control studies with 1070 cases and 1125 controls were included in the meta-analysis. Based on the results of heterogeneity, fixed-effects or random-effects models were applied to estimate the pooled ORs. The pooled ORs (95% CIs) for CYP3A5 FNx01 3 heterozygous mutant, homozygous mutant, and (heterozygous + homozygous) mutant were 1.47 (0.97-2.21), 1.05 (0.62-1.79), and 1.67 (1.14-2.44) with P = 0.07, 0.86, and 0.009, respectively. In subgroup analysis, the Z values of CYP3A5 FNx01 3 (heterozygous + homozygous) mutant and children with ALL in Asian and Caucasian populations were 1.34 and 2.51 with P = 0.18 and 0.01, respectively. No significant publication bias was detected by funnel plot. CONCLUSIONS: The current meta-analysis showed that there was association between CYP3A5 FNx01 3 polymorphism and the altered risk of ALL in children, especially in Caucasian populations.

[Changes of centrosome and related protein in malignant transformation of BEAS-2B cell induced by coal tar pitch smoke extracts].

OBJECTIVE: To analyze the centrosome abnormalities in the malignant transformation of human bronchial epithelial cells (BEAS-2B) induced by coal tar pitch smoke extracts and to investigate the role and action mechanism of centrosome in the lung cancer induced by coal tar pitch. METHODS: Medium-temperature coal tar pitch smoke extracts were used to treat immortalized human bronchial epithelial cells (BEAS-2B) and establish a malignant transformation model. The treated BEAS-2B cells were used as exposure group, and solvent control group and normal control group were also set for passage culture. The changes of centrosome in BEAS-2B cells seeded on coverslips were evaluated by indirect immunofluorescence assay. The mRNA expression of p53, p21, and cyclin E in BEAS-2B cells was measured by real-time quantitative RT-PCR, and their protein levels in BEAS-2B cells seeded on coverslips were measured by semiquantitative immunohistochemical analysis. RESULTS: The overall rate of centrosome abnormalities in BEAS-2B cells at passage 20 was 6.56±1.01% in the exposure group, significantly higher than those in the normal control group (3.40±0.86%) and solvent control group (3.14±0.59%) (P < 0.05). In addition, the exposure group had a significantly higher overall rate of centrosome abnormalities in BEAS-2B cells at passage 30 compared with the normal control group and solvent control group (22.39±9.5% vs 4.34±1.04%, P < 0.05; 22.39±9.5% vs 4.33±1.20%, P < 0.05). Compared with the normal control group and solvent control group, the exposure group had significantly decreased mRNA and protein expression of p53 and significantly increased mRNA and protein expression of cyclin E in BEAS-2B cells at passages 20 and 30 (P < 0.05). CONCLUSION: Centrosome abnormalities occur before the malignant transformation in BEAS-2B cells treated with coal tar pitch smoke extracts, and they may be mediated by the p53/p21/cyclin E signaling pathway.

[Cost-utility analysis on universal childhood hepatitis A vaccination in regions with different anti-HAV prevalence rates of China].

OBJECTIVE: To explore the inputs and outputs of areas with different anti-HAV prevalence rates on universal childhood vaccination, and to provide a scientific basis for the formulation of the immunization strategy. METHODS: Since hepatitis A vaccination was scheduled at 12 and 18 months of age for all the healthy children, a single cohort including 1 000 000 individuals was formed in 2009, using the Chinese inactivated vaccine. Decision analysis was used to build Markov-decision tree model. The universal childhood hepatitis A vaccination was compared with non-vaccination group to evaluate the number of symptomatic infection, hospitalization, death, quality-adjusted life years (QALYs) lost, and the incremental cost-utility from the health system and the societal perspectives. Outcomes of the vaccination for the next 70 years were also predicted. The process of analysis was run separately in five regions defined by the anti-HAV prevalence rates (around 50%, 50% - 69%, 70% - 79%, 80% - 89% and > 90%). Sensitivity analysis was performed to test the stability or reliability of the results, and to identify sensitive variables. RESULTS: The study projected that, in the lowest, lower, and intermediate infection regions, the cost and output indicators of universal childhood hepatitis A vaccination were all lower than non-vaccinated group. Universal vaccination could gain QALYs and save both costs from the health system or the society. In the regions with higher infection rate, the output indicators of universal childhood hepatitis A vaccination were lower than in those non-vaccinated groups, except for the number of death due to hepatitis A, which had a 20 cases of increase. The model also predicted that in the highest infected region, universal vaccination would increase 4 560 814 and 5 840 430 RMB Yuan in the total costs from both the health system and the societies, respectively, when compared to the non-vaccination groups. Universal vaccination would also decrease the numbers of symptomatic infection, hospitalization, and QALYs lost, but would increase 51 deaths due to hepatitis A, and 1507, 1929 more RMB Yuan for each QALY gained from the health system and societal respectively, in the regions with highest infection rate. Sensitivity analyses discovered that the infection rate among those susceptible population and the proportion of those who initially under protection but subsequently lost their immunity every year, were the two main sensitive variables in the model. CONCLUSION: Our research discovered that the universal vaccination strategy should be based on the protective period of the vaccine and the anti-HAV prevalence in different endemic areas.

[Construction of lentiviral mediated CyPA siRNA and its functions in non-small cell lung cancer].

OBJECTIVE: To construct a lentiviral-vector-mediated CyPA small interference RNA (siRNA) and study its function in non-small cell lung cancer. METHODS: First, four target sequences were selected according to CyPA mRNA sequence, the complementary DNA contained both sense and antisense oligonucleotides were designed, synthesized and cloned into the pGCL-GFP vector, which contained U6 promoter and green fluorescent protein (GFP). The resulting lentiviral vector containing CyPA shRNA was named Lv-shCyPA, and it was confirmed by PCR and sequencing. Next, it was cotransfected by Lipofectamine 2000 along with pHelper1.0 and pHelper 2.0 into 293T cells to package lentivirus particles. At the same time, the packed virus infected non-small cell lung cancer cell (A549), the level of CyPA protein at 5 d after infection was detected by Western Blot to screen the target of CyPA. A549 were infected with Lv-shCyPA and grown as xenografts in severe combined immunodeficient mice. Cell cycle and apoptosis were measured by FCM. RESULTS: It was confirmed by PCR and DNA sequencing that lentiviral-vector-mediated CyPA siRNA (Lv-shCyPA) producing CyPA shRNA was constructed successfully. The titer of concentrated virus were 1 x 10(7) TU/ml. Flow cytometric analysis demonstrated G2-M phase (11.40% +/- 0.68%) was decreased relatively in A549/LvshCyPA compared with control groups (14.52% +/- 1.19%) (P<0.05). The apoptosis rate of A549/Lv-shCyPA (5.01% +/- 0.5%) was higher than control groups (0.35% +/- 0.17%) (P<0.05). Visible tumors were only detectable at 6th day after inoculated by A549/Lv-shCyPA. The xenograft tumors of A549/Lv-shCyPA remarkably delayed tumor growth and remained at a similarly small average size at 38th days after inoculation compared with the control group (P < 0.05). CONCLUSION: Lentiviral-vector-mediated siRNA technique effectively inhibits the expression of CyPA, induces the NSCLC cell apoptosis, inhibits the tumor growth. Elucidation of the precise role of CypA in these pathways may lead to new targeted therapies for non-small cell lung cancer.

[Determination of SARS-CoV by simplified nested fluorescent RT-PCR].

OBJECTIVE: To establish a simple rapid and sensitive nested RT-PCR method for detection of SARS coronavirus RNA by designing the specific primers for SARS and optimizing the parameters for PCR. METHODS: Primers and fluorescent probes were designed according to the sequences of SARS coronavirus genes available from GenBank. The optimization of the parameters for PCR was performed in PE 7700 thermal cycle. The 36 serum samples and 40 mouthwash of SARS patients and 80 samples of healthy people were tested. RESULTS: The positive rate of patient serum and mouthwash was 33.6%, (12/36) and 67.5%, (27/40), respectively, while the positive rate of healthy people was zero (0/160). CONCLUSION: The simple nested RT-PCR method was a rapid, efficient and sensitive one for SARS early diagnosis.

[Coxsackie virus B types were discriminated by RT-PCR].

OBJECTIVE: To develop a method for detection of coxsackie B virus type 1-6 by RT-PCR. METHODS: A pair of primers were designed to amplify all types of coxsackie B virus 1-6 efficiently. The PCR product was hybridized in micro-wells in which 6 type specific oligonucleotide probes had been coated respectively, colorimetric detection was performed to discriminate the types of coxsackie B virus. RESULTS: This method was shown to be concordant with the IgM ELISA, 71.7% of anti-coxsackie B positive cases could be detected by RT-PCR. CONCLUSION: The RT-PCR method can type coxsackie B virus efficiently and provides a tool for clinical diagnosis and epidemiological investigation.

Soluble expression in Escherichia coli, purification and characterization of a human TF-1 cell apoptosis-related protein TFAR19.

A novel human TF-1 cell apoptosis-related protein, TFAR19, cloned from a human leukemia cell line, TF-1, was first overexpressed in Escherichia coli with the sequence Met-Gly-His(6)-Gly-Thr-Asn-Gly, a hexahistidine sequence followed by a hydroxylamine cleavage site attached to its amino terminus. The resulting protein was soluble and single-step purified to homogeneity by metal chelating affinity chromatography. After cleavage of the purified His(6)-tagged TFAR19 sample with hydroxylamine, highly purified untagged TFAR19 protein was then obtained through an FPLC Resource Q column. The structural characteristics and function of the His(6)-tagged and untagged TFAR19 proteins were studied using circular dichroism, intrinsic fluorescence, and ANS-binding fluorescence spectra and apoptosis activity assay. The results show that alpha-helix is the main secondary structure of the proteins and the two forms of TFAR19 protein fold properly, which correspond well to their apoptosis activity expression. The results also indicate that the extra sequence including the His(6)-tag fused to the N-terminus of TFAR19 protein has a minimal effect on its structure and function, suggesting that the His(6)-tagged TFAR19 protein could be further used as an immobilized target for finding potential proteins which interact with TFAR19 from a cDNA library using in vitro ribosome display technique.