Project description:Antimicrobial resistance (AMR) is a pandemic spread across multiple infectious disease microbes. To provide a new tool to study AMR, here we develop a Klebsiella pneumoniae cell-free gene expression (CFE) system. To characterise the system, we use proteomics to compare this to a Escherichia coli MG1655 CFE model, to identify relative differences and unique proteins. Then we use this native CFE system to profile antimicrobial activity in comparison to whole cell inhibition, to reveal host differences in IC50/MIC50 values. Finally, we use the CFE tool to study AMR variants, at a proof-of-concept level. As an exemplar, we show that RpoB H526L confers a 58-fold increase in CFE resistance to rifampicin – a common genotype frequently observed in rifampicin-resistant Mycobacterium tuberculosis clinical isolates. In summary, we provide a cell-free synthetic biology strategy for the profiling of antibiotic sensitivity and resistance from K. pneumoniae. While initial processing requires Biosafety Level 2, the final extracts are non-living and suitable for long-term storage, and potentially transfer to a Biosafety Level 1 lab. This bioassay has potential uses for early-stage host-specific antimicrobial development and the testing of AMR variants for structure-activity relationship studies. The data reposited is label-free high-resolution LC-MS proteomics data performed to characterise the proteins in cell-free extract of K. pneumoniae ATCC 13882 and compare to that of E. coli MG1655 to identify common and unique proteins. We also characterised the proteins of K. pneumoniae clinically resistant isolates ST258-T1b and NJST258-1, and compared them to K. pneumoniae ATCC 13882 laboratory strain.
Project description:Antimicrobial resistance (AMR) is a pandemic spread across multiple infectious disease microbes. To provide a new tool to study AMR, here we develop a Klebsiella pneumoniae cell-free gene expression (CFE) system. To characterise the system, we use proteomics to compare this to a Escherichia coli MG1655 CFE model, to identify relative differences and unique proteins. Then we use this native CFE system to profile antimicrobial activity in comparison to whole cell inhibition, to reveal host differences in IC50/MIC50 values. Finally, we use the CFE tool to study AMR variants, at a proof-of-concept level. As an exemplar, we show that RpoB H526L confers a 58-fold increase in CFE resistance to rifampicin – a common genotype frequently observed in rifampicin-resistant Mycobacterium tuberculosis clinical isolates. In summary, we provide a cell-free synthetic biology strategy for the profiling of antibiotic sensitivity and resistance from K. pneumoniae. While initial processing requires Biosafety Level 2, the final extracts are non-living and suitable for long-term storage, and potentially transfer to a Biosafety Level 1 lab. This bioassay has potential uses for early-stage host-specific antimicrobial development and the testing of AMR variants for structure-activity relationship studies. The data reposited is label-free high-resolution LC-MS proteomics data performed to characterise the proteins in cell-free extract of K. pneumoniae ATCC 13882 and compare to that of E. coli MG1655 to identify common and unique proteins. We also characterised the proteins of K. pneumoniae clinically resistant isolates ST258-T1b and NJST258-1, and compared them to K. pneumoniae ATCC 13882 laboratory strain.
Project description:The field of metabolic engineering has yielded remarkable accomplishments in using cells to produce valuable molecules, and cell-free expression (CFE) systems have the potential to push the field even further. However, CFE systems still face some outstanding challenges, including endogenous metabolic activity that is poorly understood yet has a significant impact on CFE productivity. Here, we use metabolomics to characterize the temporal metabolic changes in CFE systems and their constituent components, including significant metabolic activity in central carbon and amino acid metabolism. We find that while changing the reaction starting state <i>via</i> lysate preincubation impacts protein production, it has a comparatively small impact on metabolic state. We also demonstrate that changes to lysate preparation have a larger effect on protein yield and temporal metabolic profiles, though general metabolic trends are conserved. Finally, while we improve protein production through targeted supplementation of metabolic enzymes, we show that the endogenous metabolic activity is fairly resilient to these enzymatic perturbations. Overall, this work highlights the robust nature of CFE reaction metabolism as well as the importance of understanding the complex interdependence of metabolites and proteins in CFE systems to guide optimization efforts.
Project description:Background: Bone marrow stromal cells (BMSCs) have classically been cultured in media supplemented with 20% fetal bovine serum (FBS). As an alternative to FBS, pooled solvent detergent apheresis platelets, HPGF-C18, was evaluated for BMSC culture. Methods: A comparison of passage 2 BMSC growth revealed that 10% HPGF-C18 produced similar cell numbers as 20% FBS. Marrow aspirates from 5 healthy subjects were cultured for 4 passages in 10% HPGF-C18 or 20% FBS and were analyzed for proliferation, colony formation efficiency (CFE), surface marker expression, suppression of mixed lymphocyte reactions (MLRs), global gene and microRNA expression analysis. BMSC supernatant cytokine and growth factor concentrations were also compared. Results: Primary cultures of marrow aspirates in 10% HPGF-C18 and 20% FBS yielded similar numbers and CFE. After 4 passages, 10% HPGF-C18 and 20% FBS yielded similar numbers of BMSCs, surface marker expression patterns and immunosuppression effects. Gene and microRNA expression analysis revealed that BMSCs cultured under the two conditions had distinct expression profiles. Gene Set Enrichment Analysis (GSEA) revealed HPGF-C18-cultured BMSCs were enriched in metabolic processing and biosynthetic pathways; cell proliferation and cell cycle pathways; and immune response pathways. FBS-cultured BMSCs were enriched in MAPK signaling, TGF-beta signaling, cell adhesion and extracellular matrix pathways. Differently expressed microRNAs were related to the osteogenesis of BMSCs. Supernatant analysis found that HPGF-C18 BMSCs displayed higher levels of PEDF and TGFB1 and lower levels of IL6, VEGF, SDF1 and PLGF. Conclusions: Traditional measures; expansion, surface marker expression and inhibition of MLRs suggest that BMSC cultured in HPGF-C18 and FBS were similar, but analysis at the molecular level revealed many differences. BMSCs cultured in HPGF-C18 should be assessed in specific functional assays that reflect application-specific potency before substituting FBS with HPGF-C18.
Project description:Biotechnology has transformed the production of various chemicals and pharmaceuticals due to its efficient and selective processes, but it is inherently limited by its use of live cells as 'biocatalysts.' Cell-free expression (CFE) systems, which use a protein lysate isolated from whole cells, have the potential to overcome these challenges and broaden the scope of biomanufacturing. Implementation of CFE systems at scale will require determining clear markers of lysate activity and developing supplementation approaches that compensate for potential variability across batches and experimental protocols. Towards this goal, we use metabolomics to relate lysate preparation and performance to metabolic activity. We show that lysate processing affects the metabolite makeup of lysates, and that lysate metabolite levels change over the course of a CFE reaction regardless of whether a target compound is produced. Finally, we use this information to develop ways to standardize lysate activity and to design an improved CFE system.