Biology subjects

Vizovisek, M.

Publications and source records attributed to Vizovisek, M..

3 recordsLinked to original sources

bioRxiv2023

Engineering living immunotherapeutic agents for improved cancer treatment

Bacteria-based biohybrid agents are emerging as a promising strategy for cancer therapy due to their ability to actively target tumors, trigger localized inflammation and induce tumor regression. There has been growing interest in using bacteria that are responsive to external cues, such as magnetic fields, to facilitate the formation of robust colonies in tumor the achieve the threshold for clinical efficacy. Several studied have demonstrated the potential of innately magnetically responsive bacteria, known as magnetotactic bacteria (MTB), as steerable agents, however, their immunostimulatory properties and therapeutic effects are yet to be explored. Here, we characterize key properties of human immune cell responses and the behavior of the MTB strain Magnetospirillum magneticum AMB-1 in physiological environments. This work investigates the ability of MTB to maintain magnetic properties, viability in whole blood, cytokine production by macrophages, and the ability to increase uptake of cancer cell material by dendritic cells. This study also explores the use of MTB-liposome complexes for effective delivery of therapeutic payloads. Overall, this study establishes the potential of MTB as a versatile, combined drug delivery platform for immune-mediated cancer therapy.

bioengineering↗

bioRxiv2020

Mapping specificity, entropy, allosteric changes and substrates in blood proteases by a high-throughput protease screen

Proteases are among the largest protein families in eukaryotic phylae with more than 500 genetically encoded proteases in humans. By cleaving a wide range of target proteins, proteases are critical regulators of a vast number of biochemical processes including apoptosis and blood coagulation. Over the last 20 years, knowledge of proteases has been drastically expanded by the development of proteomic approaches to identify and quantify proteases and their substrates. In spite of their merits, some of these methods are laborious, not scalable or incompatible with native environments. Consequentially, a large number of proteases remain poorly characterized. Here, we introduce a simple proteomic method to profile protease activity based on isolation of protease products from native lysates using a 96FASP filter and their analysis in a mass spectrometer. The method is significantly faster, cheaper, technically less demanding, easily multiplexed and produces accurate protease fingerprints in near-native conditions. By using the blood cascade proteases as a case study we obtained protease substrate profiles of unprecedented depth that can be reliably used to map specificity, entropy and allosteric changes of the protease and to design fluorescent probes and predict physiological substrates. The native protease characterization method is comparable in performance, but largely exceeds the throughput of current alternatives.

biochemistry↗

bioRxiv2019

The Activome: multiplexed probing of activity of proteolytic enzymes using mass cytometry-compatible activity-based probes (TOF-probes)

The activome can be considered as a subset of the proteome that contains enzymes in their catalytically active form and can be interrogated by using probes targeted towards individual specific enzymes. A subset of such enzymes are proteases that are frequently studied with activity-based probes, small inhibitors equipped with a detectable tag, commonly a fluorophore. Due to the spectral overlap of these commonly used fluorophores, simultaneous analysis becomes limited. To overcome this, we developed a series of protease-selective lanthanide-labeled probes compatible with mass cytometry. Using lanthanide-based tags instead of fluorophores gives us the ability to monitor the activity of multiple proteases in parallel. As proof of concept we developed a panel of cathepsin and legumain specific probes and showed that we were able to identify an activome of these proteases in two cell lines and peripheral blood mononuclear cells, providing a framework for the use of mass cytometry for multiplexed enzyme activity detection.

biochemistry↗