Biology subjects

Ottenhoff, T. H. M.

Publications and source records attributed to Ottenhoff, T. H. M..

3 recordsLinked to original sources

bioRxiv2023

Identification of kinase inhibitors as potential host-directed therapies for intracellular bacteria

The emergence of antimicrobial resistance has created an urgent need for alternative treatment strategies against deadly bacterial species. In this study, we investigated the potential of kinase inhibitors as host-directed therapies (HDTs) for combating infectious diseases caused by intracellular bacteria, specifically Salmonella Typhimurium (Stm) and Mycobacterium tuberculosis (Mtb). We screened 827 ATP-competitive kinase inhibitors with known target profiles from two Published Kinase Inhibitor Sets (PKIS1 and PKIS2) using intracellular infection models for Stm and Mtb, based on human cell lines and primary macrophages. Additionally, the in vivo efficacy of the compounds was assessed using zebrafish embryo infection models. Our kinase inhibitor screen identified 14 hit compounds for Stm and 19 hit compounds for Mtb that were effective against intracellular bacteria and non-toxic for host cells. Further validation experiments showed the high efficacy of most Stm hit compounds and their ability to fully clear the intracellular infection both in cell lines and primary human macrophages. From these, two structurally related Stm hit compounds, GSK1379738A and GSK1379760A, exhibited significant effectiveness against Stm in infected zebrafish embryos. Compounds that were active against intracellular Mtb included morpholino-imidazo/triazolo-pyrimidinones that specifically target the kinases PIK3CB and PIK3CD as well as 2-aminobenzimidazoles targeting BLK, ABL1 and TRKA. Overall, this study provided insight into critical kinase targets acting at the host-pathogen interface and identified novel kinase inhibitors as potential HDTs for intracellular bacterial infections.

microbiology↗

bioRxiv2022

Neutrophil degranulation, NETosis and platelet degranulation pathway genes are co-induced in whole blood up to six months before tuberculosis diagnosis

Mycobacterium tuberculosis (M.tb) causes tuberculosis (TB) and remains one of the leading causes of mortality due to an infectious pathogen. Host immune responses have been implicated in driving the progression from infection to severe lung disease. We analyzed longitudinal RNA sequencing (RNAseq) data from the whole blood of 74 TB progressors whose samples were grouped into four six-month intervals preceding diagnosis (the GC6-74 study). We additionally analyzed RNAseq data from an independent cohort of 90 TB patients with positron emission tomography-computed tomography (PET-CT) scan results which were used to categorize them into groups with high and low levels of lung damage (the Catalysis TB Biomarker study). These groups were compared to non-TB controls to obtain a complete whole blood transcriptional profile for individuals spanning from early stages of M.tb infection to TB diagnosis. The results revealed a steady increase in the number of genes that were differentially expressed in progressors at time points closer to diagnosis with 278 genes at 13-18 months, 742 at 7-12 months and 5,131 detected 1-6 months before diagnosis and 9,205 detected in TB patients. A total of 2,144 differentially expressed genes were detected when comparing TB patients with high and low levels of lung damage. There was a large overlap in the genes upregulated in progressors 1-6 months before diagnosis (86%) with those in TB patients. A comprehensive pathway analysis revealed a potent activation of neutrophil and platelet mediated defenses including neutrophil and platelet degranulation, and NET formation at both time points. These pathways were also enriched in TB patients with high levels of lung damage compared to those with low. These findings suggest that neutrophils and platelets play a critical role in TB pathogenesis, and provide details of the timing of specific effector mechanisms that may contribute to TB lung pathology. Author summaryMycobacterium tuberculosis (M.tb) causes tuberculosis (TB) and remains one of the leading causes of mortality due to an infectious pathogen. Human immune responses must be balanced to inhibit disease progression while limiting self-damage, however in defense against M.tb host responses have been implicated in lung damage and in driving progression of M.tb infection to severe lung disease. The identification of immune responses that are activated during the development of TB could provide potential targets for interventions that might suppress disease progression, and possibly limit tissue damage. Here we identify a subset of genes that function in several biological processes that are strongly activated in the late stages of TB development and in TB patients. The proteins encoded by these genes are known to degrade lung tissue and contribute to severe lung disease.

genomics↗

bioRxiv2020

Tuberculosis causes highly conserved metabolic changes in human patients, mycobacteria-infected mice and zebrafish larvae

Tuberculosis is a highly infectious and potentially fatal disease accompanied by wasting symptoms, which cause severe metabolic changes in infected people. In this study we have compared the effect of mycobacteria infection on the level of metabolites in blood of humans and mice and whole zebrafish larvae using one highly standardized mass spectrometry pipeline, ensuring technical comparability of the results. Quantification of a range of circulating small amines showed that the levels of the majority of these compounds were significantly decreased in all three groups of infected organisms. Ten of these metabolites were common between the three different organisms comprising: methionine, asparagine, cysteine, threonine, serine, tryptophan, leucine, citrulline, ethanolamine and phenylalanine. The metabolomic changes of zebrafish larvae after infection were confirmed by nuclear magnetic resonance spectroscopy. Our study identified common biomarkers for tuberculosis disease in humans, mice and zebrafish, showing across species conservation of metabolic reprogramming processes as a result of disease. Apparently, the mechanisms underlying these processes are independent of environmental, developmental and vertebrate evolutionary factors. The zebrafish larval model is highly suited to further investigate the mechanism of metabolic reprogramming and the connection with wasting syndrome due to infection by mycobacteria.

molecular biology↗