23 research outputs found

    Drug delivery formulation impacts cyclosporine efficacy in a humanised mouse model of acute graft versus host disease

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    Acute graft versus host disease (aGvHD) is an allogeneic T cell mediated disease which manifests as a severe inflammatory disease affecting multiple organs including the liver, skin, lungs and gastrointestinal tract. Existing prophylactic and therapeutic approaches in aGvHD include the use of cyclosporine A (CyA), however the currently approved CyA formulations which were designed to optimise systemic CyA bioavailability can have a number of side effects including nephrotoxicity as well as the potential to attenuate the beneficial Graft-versus-Leukemia (GvL) effect. An added complication with CyA is that it has a narrow therapeutic window, and following oral administration is absorbed only from the small intestine, with variable cytochrome P450 metabolism contributing to intra- and inter-patient variability. This study sought to investigate the efficacy of a novel CyA oral formulation enabled by the integrated SmPill® oral drug delivery platform in a humanised mouse model of aGvHD. The study compared the approved optimised CyA (Neoral®) with SmPill®-enabled CyA and a systemic intravenous CyA formulation. Our findings clearly demonstrate superior efficacy of the novel SmPill® CyA in prolonging survival in a clinically relevant humanised aGvHD model. SmPill® CyA significantly reduced pathological score in the small intestine, colon, liver and lung of aGvHD mice. In addition, SmPill® CyA significantly reduced the levels of pro-inflammatory cytokines in all the GvHD target tissues examined. Notably, SmPill® CyA was significantly more potent in reducing GvHD associated pathology and inflammatory cytokine production compared to the optimised approved oral CyA formulation, Neoral®

    The 2021 WHO catalogue of Mycobacterium tuberculosis complex mutations associated with drug resistance: a genotypic analysis.

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    Background: Molecular diagnostics are considered the most promising route to achievement of rapid, universal drug susceptibility testing for Mycobacterium tuberculosis complex (MTBC). We aimed to generate a WHO-endorsed catalogue of mutations to serve as a global standard for interpreting molecular information for drug resistance prediction. Methods: In this systematic analysis, we used a candidate gene approach to identify mutations associated with resistance or consistent with susceptibility for 13 WHO-endorsed antituberculosis drugs. We collected existing worldwide MTBC whole-genome sequencing data and phenotypic data from academic groups and consortia, reference laboratories, public health organisations, and published literature. We categorised phenotypes as follows: methods and critical concentrations currently endorsed by WHO (category 1); critical concentrations previously endorsed by WHO for those methods (category 2); methods or critical concentrations not currently endorsed by WHO (category 3). For each mutation, we used a contingency table of binary phenotypes and presence or absence of the mutation to compute positive predictive value, and we used Fisher's exact tests to generate odds ratios and Benjamini-Hochberg corrected p values. Mutations were graded as associated with resistance if present in at least five isolates, if the odds ratio was more than 1 with a statistically significant corrected p value, and if the lower bound of the 95% CI on the positive predictive value for phenotypic resistance was greater than 25%. A series of expert rules were applied for final confidence grading of each mutation. Findings: We analysed 41 137 MTBC isolates with phenotypic and whole-genome sequencing data from 45 countries. 38 215 MTBC isolates passed quality control steps and were included in the final analysis. 15 667 associations were computed for 13 211 unique mutations linked to one or more drugs. 1149 (7·3%) of 15 667 mutations were classified as associated with phenotypic resistance and 107 (0·7%) were deemed consistent with susceptibility. For rifampicin, isoniazid, ethambutol, fluoroquinolones, and streptomycin, the mutations' pooled sensitivity was more than 80%. Specificity was over 95% for all drugs except ethionamide (91·4%), moxifloxacin (91·6%) and ethambutol (93·3%). Only two resistance mutations were identified for bedaquiline, delamanid, clofazimine, and linezolid as prevalence of phenotypic resistance was low for these drugs. Interpretation: We present the first WHO-endorsed catalogue of molecular targets for MTBC drug susceptibility testing, which is intended to provide a global standard for resistance interpretation. The existence of this catalogue should encourage the implementation of molecular diagnostics by national tuberculosis programmes. Funding: Unitaid, Wellcome Trust, UK Medical Research Council, and Bill and Melinda Gates Foundation

    An oral alpha-galactosylceramide adjuvanted Helicobacter pylori vaccine induces protective IL-1R- and IL-17R-dependent Th1 responses

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    Helicobacter pylori causes chronic gastric infection that can lead to peptic ulcers and is an identified risk factor for gastric cancer development. Although much effort has been put into the development of a Helicobacter pylori vaccine over the last three decades, none has yet reached clinical application. Specific challenges pertaining to effective H. pylori vaccine development include the lack of proven vaccine-effective antigens and safe mucosal adjuvants to enhance local immune responses as well as the lack of accepted correlates of protection. Herein, we demonstrate that prophylactic intragastric immunisation with a whole-cell killed H. pylori antigen administered together with the non-toxic oral adjuvant ?-galactosylceramide (?-GalCer) induced effective immune protection against H. pylori infection in mice, which was of similar magnitude as when using the ?gold standard? cholera toxin as adjuvant. We further describe that this ?-GalCer-adjuvanted vaccine formulation elicited strong intestinal and systemic Th1 responses as well as significant antigen-specific mucosal and systemic antibody responses. Finally, we report that the protective intestinal Th1 responses induced by ?-GalCer are dependent on CD1d, IL-1R as well as IL-17R signalling. In summary, our results show that ?-GalCer is a promising adjuvant for inclusion in an oral vaccine against H. pylori infection
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