bTo develop a stable and marker-free Lactobacillus strain useful for the expression of vaccines, we developed a temperature-sensitive suicide plasmid with expression cassettes containing an HCE promoter, a PgsA anchor, the alpha-toxin gene, and an rrnB T1T2 terminator (PP␣T) that uses a 5-fluorouracil (5-FU) counterselectable marker for Lactobacillus casei. Three strains containing the correct PP␣T expression cassettes were produced via the selective pressure of 5-FU screening. We confirmed that the upp gene was deleted and that the PP␣T expression cassettes were inserted into the upp site of L. casei ATCC 393 by genomic PCR amplification and sequencing. 5-FU resistance in recombinant bacteria could be stably inherited for as long as 40 generations following insertion. However, bacteria containing the integrated DNA grew more slowly than wild-type L. casei. An indirect enzyme-linked immunosorbent assay (ELISA) analysis demonstrated that the alpha-toxin gene was expressed. Also, we visualized expression of the protein on the surface of L. casei cells using laser confocal microscopy. These results taken together demonstrate that these recombinant bacteria should provide a safe tool for effective vaccine production.
Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use: https://youtu.be/ERjzrETqVkE Objective and Design: Allergic rhinitis (AR) is an immunoglobulin E (IgE)-mediated inflammatory respiratory hypersensitivity characterized by elevated Th2 cytokines and infiltration of inflammatory cells to nasal tissues. BX471 is a small-molecule CC chemokine receptor type 1 (CCR1) antagonist involved in suppression of inflammation via blocking of primary ligands. In this study, we examined the anti-inflammatory effect of BX471 on ovalbumin (OVA)-induced AR mice model. Materials and Methods: Levels of OVA-specific IgE and Th1 cytokines were determined by enzyme-linked immunosorbent assay (ELISA). Nasal expression of proinflammatory mediators was assessed by real-time polymerase chain reaction (RT-qPCR). Nasal-cavity sections were stained with hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) to study eosinophil infiltration and goblet cell metaplasia. Relative protein levels of Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-kB), Toll-like Receptor 4 (TLR4) and Toll-like-receptor 2 (TLR2) were assessed by Western Blot. Percentage of CD4 + CD25 + Foxp3 + T regulatory cells (Treg) was measured by flow cytometry. Results: Mice treated with BX471 showed significantly relieved sneezing and nasal-rubbing behaviors. The expression of nasal proinflammatory factors was significantly downregulated by BX471, and protein levels of tumor necrosis factor alpha (TNF-α) and NF-kB were suppressed. Blockade of CCR1 ligands inhibited eosinophil recruitment in nasal cavity. In addition, Treg cells population were upregulated in BX471-treated mice. Conclusion: BX471 exerts anti-inflammatory effects in a mouse model of AR by inhibiting CCR1-mediated TNF-α production, which subsequently suppresses NF-kB activation in inflammatory cells, leading to a decrease in Th2 cytokines, IL-1β, VCAM-1, GM-CSF, RANTES, and MIP-1α expression levels, thus inhibiting eosinophil recruitment to nasal mucosa. In addition, BX-471 exhibits anti-allergic effect by increasing Treg cell population. Overall, BX471 represents a promising therapeutic strategy against AR.
The relationship between atopic diseases and cancer at various sites has been extensively studied. Previous epidemiological studies have investigated the association between atopic diseases and bladder cancer; however, the results remain inconclusive. In this study, we performed a systematic review and meta-analysis of cohort studies published thus far to evaluate the association between atopy and the risk of bladder cancer. We conducted a systematic search in PubMed, Embase, ISI Web of Science, and Scopus to identify potentially relevant studies. The pooled risk ratio (RRs) and 95% confidence intervals (95% CIs) were calculated using a random-effect model considering the heterogeneity among studies. On the basis of our selection criteria, a total of 10 cohort studies were included in our meta-analysis involving 2,341,005 participants, of whom 1720 were patients with bladder cancer. The pooled RR of bladder cancer in the group with atopic disease versus the group without atopic disease was 1.31 (95% CI: 1.10–1.56, p < 0.01), indicating a positive association between overall atopy and bladder cancer risk. In subgroup analysis, the pooled RR of bladder cancer was 1.46 (95% CI: 1.18–1.80, p < 0.001) for asthma and 1.03 (95% CI: 0.74–1.44, p = 0.86) for allergic rhinitis. The risk of bladder cancer is positively associated with overall atopy and asthma, but is not associated with allergic rhinitis.
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