Biology subjects

Tampere, M.

Publications and source records attributed to Tampere, M..

4 recordsLinked to original sources

bioRxiv2025

Morphological cell profiling for drug repurposing against SARS-CoV-2 infection

Antiviral drug discovery has traditionally focused on targeting viral proteins, while host-directed strategies remain largely underexplored. Here, present a systematic drug repurposing strategy leveraging morphological profiling to identify host-targeting antivirals. Our image-based approach combines viral protein immunostaining with high-content Cell Painting analysis to simultaneously assess viral replication and provide in-depth analysis of host cell responses. By screening 5,275 repurposable drugs against SARS-CoV-2 infected cells, we identified compounds that reversed the infected cell phenotype, including ones not detected by conventional cytopathicity and antibody-based assays. A counter-screen excluded compounds whose antiviral activity was likely driven by drug-induced phospholipidosis (DIPL). Pathway enrichment analysis of compounds validated by both Cell Painting dose-response and DIPL assays, revealed host processes frequently hijacked by viruses, including innate immune responses and kinases. Among the top hits, both novel candidates, such as serdemetan, and previously reported broad-spectrum antivirals, such as sunitinib, were identified. Our approach constitutes an adaptable and scalable platform suited for diverse viral pathogens and cell systems. We provide a resource of open access screening data, images, and automated analysis pipelines to advance both antiviral discovery and pandemic preparedness.

microbiology↗

bioRxiv2025

Uridine cytidine kinases dictate the therapeutic response of molnupiravir via its bioactivation

Molnupiravir is a nucleoside analogue antiviral drug with activities against a broad spectrum of RNA viruses, including its clinical indication SARS-CoV-2. Whilst its antiviral mechanism-of-action is well defined, host pharmacogenetic factors that regulate its therapeutic responses - efficacy as well as selectivity - have not been mechanistically deciphered and characterized. Here we identified that uridine cytidine kinase (UCK), the first and rate-limiting kinase of the pyrimidine salvage pathway, could effectively phosphorylate N4-hydroxycytidine (NHC), the active compound of molnupiravir, and thereby dictate its anti-SARS-CoV-2 efficacy, as well as its selectivity index. Using target engagement and enzyme kinetic assays, we demonstrate that recombinant UCK isoform 1 (UCK1) and 2 (UCK2) effectively bind and phosphorylate NHC, with UCK2 displaying 9-fold higher catalytic efficiency. Accordingly, in SARS-CoV-2-infected cells, downregulation of UCK2 via siRNA hampered the intracellular accumulation of the triphosphate antiviral metabolite of NHC, resulting in 10-fold reduction of antiviral efficacy. Furthermore, we could recapitulate this using a pan-UCK small molecule inhibitor. Critically, both UCK downregulation and inhibition significantly reduced the selectivity index of molnupiravir/NHC. Altogether, this work underscores the pivotal roles of UCK enzymes in upholding molnupiravir efficacy and therapeutic window, and furthermore, highlights their potential as pharmacologically tractable targets for tailoring the therapeutic response to this antiviral agent.

microbiology↗

bioRxiv2023

Proteoform-level deconvolution reveals a broader spectrum of ibrutinib off-targets

Over the last decade, proteome-wide mapping of drug interactions has revealed that most targeted drugs bind to not only their intended targets, but additional proteins as well. However, the majority of these studies have focused on analyzing proteins as encoded by their genes, thus neglecting the fact that most proteins exist as dynamic populations of multiple proteoforms. Here, we addressed this problem by combining the use of thermal proteome profiling (TPP), a powerful method for proteome analysis, with proteoform detection to refine the target landscape of an approved drug, ibrutinib. We revealed that, in addition to known targets, ibrutinib exhibits an intricate network of interactions involving multiple different proteoforms. Notably, we discovered affinity for specific proteoforms that link ibrutinib to mechanisms in immunomodulation and cellular processes like Golgi trafficking, endosomal trafficking, and glycosylation. These insights provide a framework for interpreting clinically observed off-target and adverse events. More generally, our findings highlight the importance of proteoform-level deconvolution in understanding drug interactions and their functional impacts, and offer a critical perspective for drug mechanism studies and potential applications in precision medicine.

molecular biology↗

bioRxiv2022

Subcellular mapping of the protein landscape of SARS-CoV-2 infected cells for target-centric drug repurposing

The COVID-19 pandemic has resulted in millions of deaths and affected socioeconomic structure worldwide and the search for new antivirals and treatments are still ongoing. In the search for new drug target and to increase our understanding of the disease, we used large scale immunofluorescence to explore the host cell response to SARS-CoV-2 infection. Among the 602 host proteins studied in this host response screen, changes in abundance and subcellular localization were observed for 97 proteins, with 45 proteins showing increased abundance and 10 reduced abundances. 20 proteins displayed changed localization upon infection and an additional 22 proteins displayed altered abundance and localization, together contributing to diverse reshuffling of the host cell protein landscape. We then selected existing and approved small-molecule drugs (n =123) against our identified host response proteins and identified 3 compounds - elesclomol, crizotinib and rimcazole, that significantly reduced antiviral activity. Our study introduces a novel, targeted and systematic approach based on host protein profiling, to identify new targets for drug repurposing. The dataset of [~]75,000 immunofluorescence images from this study are published as a resource available for further studies.

cell biology↗