Broad-spectrum in vitro activity of macrophage infectivity potentiator inhibitors against Gram-negative bacteria and Leishmania major

Background The macrophage infectivity potentiator (Mip) protein, which belongs to the immunophilin superfamily, is a peptidyl-prolyl cis/trans isomerase (PPIase) enzyme. Mip has been shown to be important for virulence in a wide range of pathogenic microorganisms. It has previously been demonstrated that small-molecule compounds designed to target Mip from the Gram-negative bacterium Burkholderia pseudomallei bind at the site of enzymatic activity of the protein, inhibiting the in vitro activity of Mip. Objectives In this study, co-crystallography experiments with recombinant B. pseudomallei Mip (BpMip) protein and Mip inhibitors, biochemical analysis and computational modelling were used to predict the efficacy of lead compounds for broad-spectrum activity against other pathogens. Methods Binding activity of three lead compounds targeting BpMip was verified using surface plasmon resonance spectroscopy. The determination of crystal structures of BpMip in complex with these compounds, together with molecular modelling and in vitro assays, was used to determine whether the compounds have broad-spectrum antimicrobial activity against pathogens. Results Of the three lead small-molecule compounds, two were effective in inhibiting the PPIase activity of Mip proteins from Neisseria meningitidis, Klebsiella pneumoniae and Leishmania major. The compounds also reduced the intracellular burden of these pathogens using in vitro cell infection assays. Conclusions These results indicate that Mip is a novel antivirulence target that can be inhibited using small-molecule compounds that prove to be promising broad-spectrum drug candidates in vitro. Further optimization of compounds is required for in vivo evaluation and future clinical applications

Whither magnetic hyperthermia? A tentative roadmap

The scientific community has made great efforts in advancing magnetic hyperthermia for the last two decades after going through a sizeable research lapse from its establishment. All the progress made in various topics ranging from nanoparticle synthesis to biocompatibilization and in vivo testing have been seeking to push the forefront towards some new clinical trials. As many, they did not go at the expected pace. Today, fruitful international cooperation and the wisdom gain after a careful analysis of the lessons learned from seminal clinical trials allow us to have a future with better guarantees for a more definitive takeoff of this genuine nanotherapy against cancer. Deliberately giving prominence to a number of critical aspects, this opinion review offers a blend of state-of-the-art hints and glimpses into the future of the therapy, considering the expected evolution of science and technology behind magnetic hyperthermia.status: publishe

Novel mesoporous silica–perfluorosulfonic acid hybrids as strong heterogeneous Brønsted catalysts

Perfluorinated sulfonic acids have been immobilised into mesoporous silica frameworks by a one-step process, representing the first example of the successful incorporation of charged silanes using this route, and have been shown to be excellent catalysts for Brønsted acid catalysed transformations

Recurring BALB/c mouse lung inflammatory responses to episodic allergen exposure

This study detailed the sequence of recurring inflammatory events associated with episodic allergen exposures of mice resulting in airway hyperreactivity, sustained inflammation, goblet-cell hyperplasia, and fibrogenesis that characterize a lung with chronic asthma. Ovalbumin (OVA)-sensitized female BALB/c mice were exposed to saline-control or OVA aerosols for 1 h per day for episodes of 3 d/wk for up to 8 wk. Lung inflammation was assessed by inflammatory cell recoveries using bronchoalveolar lavages (BAL) and tissue collagenase dispersions. Cell accumulations were observed within airway submucosal and associated perivascular spaces using immunohistochemical and tinctorial staining methods. Airway responsiveness to methacholine aerosols were elevated after 2 wk and further enhanced to a sustained level after wk 4 and 8. Although by wk 8 diminished OVA-induced accumulations of eosinophils, neutrophils, and monocyte-macrophages were observed, suggesting diminished responsiveness, the BAL recovery of lymphocytes remained elevated. Airway but not perivascular lesions persisted with a proliferating cell population, epithelial goblet-cell hyperplasia, and evidence of enhanced collagen deposition. Examination of lung inflammatory cell content before the onset of the first, second, and fourth OVA exposure episodes demonstrated enhancements in residual BAL lymphocyte and BAL and tissue eosinophil recoveries with each exposure episode. Although tissue monocyte-macrophage numbers returned to baseline prior to each exposure episode, the greatest level of accumulation was observed after wk 4. These results provide the basis for establishing the inflammatory and exposure criteria by which episodic environmental exposures to allergen might result in the development of a remodeled lung in asthma