RESUMO
Antibiotic treatments have detrimental effects on the microbiome and lead to antibiotic resistance. To develop a phage therapy against a diverse range of clinically relevant Escherichia coli, we screened a library of 162 wild-type (WT) phages, identifying eight phages with broad coverage of E. coli, complementary binding to bacterial surface receptors, and the capability to stably carry inserted cargo. Selected phages were engineered with tail fibers and CRISPR-Cas machinery to specifically target E. coli. We show that engineered phages target bacteria in biofilms, reduce the emergence of phage-tolerant E. coli and out-compete their ancestral WT phages in coculture experiments. A combination of the four most complementary bacteriophages, called SNIPR001, is well tolerated in both mouse models and minipigs and reduces E. coli load in the mouse gut better than its constituent components separately. SNIPR001 is in clinical development to selectively kill E. coli, which may cause fatal infections in hematological cancer patients.
Assuntos
Bacteriófagos , Escherichia coli , Animais , Humanos , Camundongos , Suínos , Escherichia coli/genética , Bacteriófagos/genética , Sistemas CRISPR-Cas/genética , Porco Miniatura , AntibacterianosRESUMO
INTRODUCTION: Lately, zirconium-89 has shown great promise as a radionuclide for PET applications of long circulating biomolecules. Here, the design and synthesis of protracted and long-lived GLP-1 receptor agonists conjugated to desferrioxamine and labelled with zirconium-89 is presented with the purpose of studying their in vivo distribution by PET imaging. The labelled conjugates were evaluated and compared to a non-labelled GLP-1 receptor agonist in both in vitro and in vivo assays to certify that the modification did not significantly alter the peptides' structure or function. Finally, the zirconium-89 labelled peptides were employed in PET imaging, providing visual verification of their in vivo biodistribution. METHODS: The evaluation of the radiolabelled peptides and comparison to their non-labelled parent peptide was performed by in vitro assays measuring binding and agonistic potency to the GLP-1 receptor, physicochemical studies aiming at elucidating change in peptide structure upon bioconjugation and labelling as well as an in vivo food in-take study illustrating the compounds' pharmacodynamic properties. The biodistribution of the labelled GLP-1 analogues was determined by ex vivo biodistribution and in vivo PET imaging. RESULTS: The results indicate that it is surprisingly feasible to design and synthesize a protracted, zirconium-89 labelled GLP-1 receptor agonist without losing in vitro potency or affinity as compared to a non-labelled parent peptide. Physicochemical properties as well as pharmacodynamic properties are also maintained. The biodistribution in rats shows high accumulation of radiolabelled peptide in well-perfused organs such as the liver, kidney, heart and lungs. The PET imaging study confirmed the findings from the biodistribution study with a significant high uptake in kidneys and presence of activity in liver, heart and larger blood vessels. CONCLUSIONS AND ADVANCES IN KNOWLEDGE: This initial study indicates the potential to monitor the in vivo distribution of long-circulating incretin hormones using zirconium-89 based PET.
Assuntos
Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Peptídeos/química , Peptídeos/farmacologia , Tomografia por Emissão de Pósitrons/métodos , Radioisótopos/química , Zircônio/química , Sequência de Aminoácidos , Técnicas de Química Sintética , Desenho de Fármacos , Meia-Vida , Marcação por Isótopo , Peptídeos/síntese química , Peptídeos/farmacocinética , Radioquímica , Distribuição TecidualRESUMO
Tumour necrosis factor (TNF)-α inhibitors are registered for treatment of several severe dermatologic, rheumatologic and gastrointestinal diseases. Due to TNF-α's important role in the immune system patients have increased risk of serious infections during treatment with TNF-α inhibitor. We here present a case of miliary tuberculosis complicated by pericardial effusion in a Danish man treated with TNF-α inhibitor that emphasizes the need for rapid examination of new symptoms in this patient category.