A vaccine for Ebola virus – approaches and results of accelerated process development and characterization studies

In 2014, West Africa experienced the worst outbreak of Ebola virus in history with 10 times more cases than in all previous outbreaks combined. In response to this public health emergency, MSD and a global network of partners collaborated to speed the research, development, and deployment of a candidate vaccine that ultimately provided the first evidence of efficacy in human subjects for any Ebola vaccine. While work continues to ultimately license the candidate vaccine, a risk-based approach to process development and characterization was used to accelerate and prioritize the study of parameters. Risk was evaluated by experts familiar with unit operations and parameters in similar licensed live viral vaccines and resulted in an overall plan of study encompassing five major areas – cell expansion, viral infection, purification, formulation, and general robustness. In parallel to batch size scale-up to support commercial production, a scale-down model comparable to commercial scale production was developed and enabled high-throughput experimentation. This approach reduced experiment cycle time from eight weeks to three weeks, reduced process volumes enabling design of experiments, and resulted in high-throughput execution of lab-scale studies. Typically, potency is extremely sensitive to multiplicity of infection (MOI); this vaccine is capable of producing acceptable potencies during viral infection with a 1000x range of MOIs. The most critical parameter during purification is digestion, which results in a ~10-fold increase in product potency. The final tangential flow filtration unit operation is extremely robust with no critical process parameters while still being capable of effectively clearing residual enzyme. Additionally, the implementation of a fully disposable single-use drug substance manufacturing process also helped accelerate process development and characterization activities. Component user requirements and schematic drawings were used to design prototypes which were evaluated using innovative shake-down studies. This approach resulted in a rugged system of end-to-end, single-use disposable components with 42 modular, “plug-and-play” designs available to support \u3e500 single-use assemblies needed in production. Components were delivered to the commercial manufacturing site within 15 months with no required design changes following water-run testing. Taken together these approaches helped accelerate process development and characterization studies that will expedite the licensure of an Ebola virus vaccine

Combined ligand and fragment-based drug design of selective histone deacetylase – 6 inhibitors

Histone deacetylase 6 (HDAC6) is unique hydrolase within HDAC family, having pleiotropic deacetylase activity against α-tubulin, cortactin and dynein. Comprehensively, HDAC6 controls cell motility, apoptosis and protein folding, whereas alterations in its structure and function are related to the pathogenesis of cancer, neurodegeneration and inflammation. To define structural motifs which guide HDAC6 selectivity, we developed and compared three-dimensional Quantitative Structure-Activity Relationship (3D-QSAR) models for HDAC1 and HDAC6 inhibitors. The reduction of the bias in conformer generation was supported by virtual docking study by using crystal structures of human HDAC1 and HDAC6 isoforms. Following these findings, the combined ligand-based and fragment-based drug design methodologies were used in the design of selective HDAC6 inhibitors. Group of the most promising novel ligands was selected based on the predicted HDAC6 selectivity, pharmacokinetic profile, synthetic tractability, and in silico cytotoxicity against the wide range of human cancer cell lines

Transformation of Cs-exchanged clinoptilolite to CsAlSi5O12 by hot-pressing

Dense CsAlSi5O12 was successfully obtained by hot pressing of Cs-exchanged clinoptilolite at 900 degrees C. Simultaneous application of high temperature and mechanical pressure allowed formation of CsAlSi5O12 at temperature considerably lower than 1150 degrees C which was the lowest reported temperature of CsAlSi5O12 formation in pressureless sintered Cs-exchanged clinoptilolite. CsAlSi5O12 formation was preceded by complete amorphisation of Cs-exchanged clinoptilolite in temperature range between 700 and 900 degrees C. Bearing in mind that clinoptilolite possesses high affinity for Cs cation it is believed that hot pressing of Cs-exchanged clinoptilolite might be an efficient way to immobilize radioactive Cs by its incorporation into crystal lattice of stable CsAlSi5O12. The samples sintered at 950 degrees C had relative density about 84% of theoretical density and open porosity of only 6% which is expected to result in low Cs leaching rate

Front Cover: Modulating Proteinâ Protein Interactions with Visibleâ Lightâ Responsive Peptide Backbone Photoswitches (ChemBioChem 11/2019)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149531/1/cbic201900304.pd

Quinazoline-based analog of adenine as an antidote against MLL-rearranged leukemia cells: synthesis, inhibition assays and docking studies

International audienceBackground: Post-translational modifications of histones constitute a dynamic process impacting gene expression. A well-studied modification is lysine methylation. Among the lysine histone methyltransferases, DOT1L is implicated in various diseases, making it a very interesting target for drug discovery. DOT1L has two substrates, the SAM cofactor that gives the methyl group and the lysine H3K79 substrate. Results: Using molecular docking, the authors explored new bisubstrate analogs to enlarge the chemical landscape of DOT1L inhibitors. The authors showed that quinazoline can successfully replace the adenine in the design of bisubstrate inhibitors of DOT1L, showing similar activity compared with the adenine derivative but with diminished cytotoxicity. Conclusion: The docking model is validated together with the use of quinazoline in the design of bisubstrate inhibitors

An Integrative in Silico Drug Repurposing Approach for Identification of Potential Inhibitors of SARS-CoV-2 Main Protease

Aims: An infectious disease (COVID-19) caused by the coronavirus SARS-CoV-2 emerged in Wuhan, China in December 2019. Currently, SARS-CoV-2 infected more than 9 million people and caused more than 450 000 deaths. Considering the urgent need for novel therapeutics, drug repurposing approach might offer rapid solutions comparing to de novo drug design. In this study, we investigated an integrative in silico drug repurposing approach as a valuable tool for rapid selection of potential candidates against SARS-CoV-2 Main Protease (Mpro).Main methods: To screen FDA-approved drugs, we designed an integrative in silico drug repurposing approach implementing structure-based molecular modelling techniques, physiologically-based pharmacokinetic (PBPK) modelling of drugs disposition and data-mining analysis of drug-gene-COVID-19 association.Key findings: Through the presented approach, 43 candidates with potential inhibitory effect on Mpro were selected and further evaluated according to the predictions of tissue disposition, drug-gene-COVID-19 associations and potential pleiotropic effects. We singled out 9 FDA approved drugs as the most promising for their profiling in COVID-19 drug discovery campaigns. Our results were in agreement with current experimental findings, which validate the applied integrative approach and may support clinical decisions for a novel epidemic wave of COVID-19.Significance: To the best of our knowledge, this is the first integrative in silico repurposing study for COVID-19 with a clear advantage in linking structure-based molecular modeling of Mpro inhibitors with predictions of tissue disposition, drug-gene-COVID-19 associations and prediction of pleiotropic effects of selected candidates.</div

Discovery of 1-benzhydryl piperazine-based HDAC inhibitors with anti-cancer and anti-metastatic properties against human breast cancer: synthesis, molecular modeling, in vitro and in vivo biological evaluation

Isoform-selective histone deacetylase (HDAC) inhibition is promoted as a rational strategy to develop safer anti-cancer drugs compared to non-selective HDAC inhibitors. Despite this presumed benefit, considerably more non-selective HDAC inhibitors have undergone clinical trials. In this report, we detail the design and discovery of potent HDAC inhibitors with 1-benzhydryl piperazine as a surface recognition group that differ in hydrocarbon linker. Surprisingly, in vitro HDAC screening identified two selective HDAC6 inhibitors (6b, IC50 = 186 nM and 9b, IC50 = 31 nM), as well as two non-selective nanomolar HDAC inhibitors (7b and 8b). The influence of linker chemistry of synthesized inhibitors on HDAC6 potency was studied using structure-based molecular modelling. The breast cancer cell-lines (MDA-MB-231 and MCF-7) were used to evaluate compound mediated in vitro anti-cancer, anti-migratory, and anti-invasive activities, leading to 8b as the most promising compound. In our study, 8b is identified as the HDAC inhibitor with very potent anti-angiogenic, anti-metastatic and anti-tumor effects in zebrafish MDA-MB-231 xenograft models at low micromolar concentrations

Bistable Photoswitch Allows in Vivo Control of Hematopoiesis

Optical control has enabled functional modulation in cell culture with unparalleled spatiotemporal resolution. However, current tools for in vivo manipulation are scarce. Here, we design and implement a genuine on-off optochemical probe capable of achieving hematopoietic control in zebrafish. Our photopharmacological approach first developed conformationally strained visible light photoswitches (CS-VIPs) as inhibitors of the histone methyltransferase MLL1 (KMT2A). In blood homeostasis MLL1 plays a crucial yet controversial role. CS-VIP 8 optimally fulfils the requirements of a true bistable functional system in vivo under visible-light irradiation, and with unprecedented stability. These properties are exemplified via hematopoiesis photoinhibition with a single isomer in zebrafish. The present interdisciplinary study uncovers the mechanism of action of CS-VIPs. Upon WDR5 binding, CS-VIP 8 causes MLL1 release with concomitant allosteric rearrangements in the WDR5/RbBP5 interface. Since our tool provides on-demand reversible control without genetic intervention or continuous irradiation, it will foster hematopathology and epigenetic investigations. Furthermore, our workflow will enable exquisite photocontrol over other targets inhibited by macrocycles

Bistable Photoswitch Allows in Vivo Control of Hematopoiesis

International audienceOptical control has enabled functional modulation in cell culture with unparalleled spatiotemporal resolution. However, current tools for in vivo manipulation are scarce. Here, we design and implement a genuine on-off optochemical probe capable of achieving hematopoietic control in zebrafish. Our photopharmacological approach first developed conformationally strained visible light photoswitches (CS-VIPs) as inhibitors of the histone methyltransferase MLL1 (KMT2A). In blood homeostasis MLL1 plays a crucial yet controversial role. CS-VIP 8 optimally fulfils the requirements of a true bistable functional system in vivo under visible-light irradiation, and with unprecedented stability. These properties are exemplified via hematopoiesis photoinhibition with a single isomer in zebrafish. The present interdisciplinary study uncovers the mechanism of action of CS-VIPs. Upon WDR5 binding, CS-VIP 8 causes MLL1 release with concomitant allosteric rearrangements in the WDR5/RbBP5 interface. Since our tool provides on-demand reversible control without genetic intervention or continuous irradiation, it will foster hematopathology and epigenetic investigations. Furthermore, our workflow will enable exquisite photocontrol over other targets inhibited by macrocycles