Chiara Medaglia

Dr. Chiara Medaglia

Department of Microbiology and Molecular Medicine, University of Geneva Medical School, 1211 Geneva, Switzerland.

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 August 2020 in Microorganisms
Verified
Journal Article
Open access
PDF file
PCPaola Cuomo
Paola Cuomo
MPMarina Papaianni
Marina Papaianni
AFAndrea Fulgione
Andrea Fulgione
Fabrizia GuerraFabrizia Guerra
Fabrizia Guerra
RCRosanna Capparelli
Rosanna Capparelli
CMChiara Medaglia
Chiara Medaglia
Helicobacter pylori (H. pylori) is a Gram-negative bacterium which colonizes the human stomach. The ability of H. pylori to evade the host defense system and the emergence of antibiotic resistant strains result in bacteria persistence and chronic inflammation, which leads to both severe gastric and extra-gastric diseases. Consequently, innovative approaches able to overcome H. pylori clinical outcomes are needed. In this work, we develop a novel non-toxic therapy based on the synergistic action of H. pylori phage and lactoferrin adsorbed on hydroxyapatite nanoparticles, which effectively impairs bacteria colonization and minimizes the damage of the host pro-inflammatory response.

Verified
Journal Article
Open access
PDF file
PCPaola Cuomo
Paola Cuomo
MPMarina Papaianni
Marina Papaianni
Clementina SansoneClementina Sansone
Clementina Sansone
Antonio IannelliAntonio Iannelli
Antonio Iannelli
DIDomenico Iannelli
Domenico Iannelli
RCRosanna Capparelli
Rosanna Capparelli
Helicobacter pylori (Hp) is a Gram-negative bacterium colonizing the human stomach. Nuclear Magnetic Resonance (NMR) analysis of intracellular human gastric carcinoma cells (MKN-28) incubated with the Hp cell filtrate (Hpcf) displays high levels of amino acids, including the branched chain amino acids (BCAA) isoleucine, leucine, and valine. Polymerase chain reaction (PCR) Array Technology shows upregulation of mammalian Target Of Rapamycin Complex 1 (mTORC1), inflammation, and mitochondrial dysfunction. The review of literature indicates that these traits are common to type 2 diabetes, obesity, Alzheimer’s diseases, and cardiometabolic disease. Here, we demonstrate how Hp may modulate these traits. Hp induces high levels of amino acids, which, in turn, activate mTORC1, which is the complex regulating the metabolism of the host. A high level of BCAA and upregulation of mTORC1 are, thus, directly regulated by Hp. Furthermore, Hp modulates inflammation, which is functional to the persistence of chronic infection and the asymptomatic state of the host. Finally, in order to induce autophagy and sustain bacterial colonization of gastric mucosa, the Hp toxin VacA localizes within mitochondria, causing fragmentation of these organelles, depletion of ATP, and oxidative stress. In conclusion, our in vitro disease model replicates the main traits common to the above four diseases and shows how Hp may potentially manipulate them.

1 June 2021 in Microorganisms
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Journal Article
Open access
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CMChiara Medaglia
Chiara Medaglia
AZArnaud Charles-Antoine Zwygart
Arnaud Charles-Antoine Zwygart
PSPaulo Jacob Silva
Paulo Jacob Silva
SCSamuel Constant
Samuel Constant
SHSong Huang
Song Huang
Caroline TapparelCaroline Tapparel
Caroline Tapparel
Influenza viruses are a leading cause of morbidity and mortality worldwide. These air-borne pathogens are able to cross the species barrier, leading to regular seasonal epidemics and sporadic pandemics. Influenza viruses also possess a high genetic variability, which allows for the acquisition of resistance mutations to antivirals. Combination therapies with two or more drugs targeting different mechanisms of viral replication have been considered an advantageous option to not only enhance the effectiveness of the individual treatments, but also reduce the likelihood of resistance emergence. Using an in vitro infection model, we assessed the barrier to viral resistance of a combination therapy with the neuraminidase inhibitor oseltamivir and human interferon lambda against the pandemic H1N1 A/Netherlands/602/2009 (H1N1pdm09) virus. We serially passaged the virus in a cell line derived from human bronchial epithelial cells in the presence or absence of increasing concentrations of oseltamivir alone or oseltamivir plus interferon lambda. While the treatment with oseltamivir alone quickly induced the emergence of antiviral resistance through a single mutation in the neuraminidase gene, the co-administration of interferon lambda delayed the emergence of drug-resistant influenza virus variants. Our results suggest a possible clinical application of interferon lambda in combination with oseltamivir to treat influenza.

Verified
Journal Article
Open access
PDF file
PCPaola Cuomo
Paola Cuomo
MPMarina Papaianni
Marina Papaianni
RCRosanna Capparelli
Rosanna Capparelli
CMChiara Medaglia
Chiara Medaglia
Formyl peptide receptors (FPRs) are cell surface pattern recognition receptors (PRRs), belonging to the chemoattractant G protein-coupled receptors (GPCRs) family. They play a key role in the innate immune system, regulating both the initiation and the resolution of the inflammatory response. FPRs were originally identified as receptors with high binding affinity for bacteria or mitochondria N-formylated peptides. However, they can also bind a variety of structurally different ligands. Among FPRs, formyl peptide receptor-like 1 (FPRL1) is the most versatile, recognizing N-formyl peptides, non-formylated peptides, and synthetic molecules. In addition, according to the ligand nature, FPRL1 can mediate either pro- or anti-inflammatory responses. Hp(2-20), a Helicobacter pylori-derived, non-formylated peptide, is a potent FPRL1 agonist, participating in Helicobacter pylori-induced gastric inflammation, thus contributing to the related site or not-site specific diseases. The aim of this review is to provide insights into the role of FPRs in H. pylori-associated chronic inflammation, which suggests this receptor as potential target to mitigate both microbial and sterile inflammatory diseases.

Verified
Journal Article
Open access
PDF file
PCPaola Cuomo
Paola Cuomo
CMChiara Medaglia
Chiara Medaglia
IAIvana Allocca
Ivana Allocca
AMAngela Michela Immacolata Montone
Angela Michela Immacolata Montone
Fabrizia GuerraFabrizia Guerra
Fabrizia Guerra
RCRosanna Capparelli
Rosanna Capparelli
The identification of novel strategies to control Helicobacter pylori (Hp)-associated chronic inflammation is, at present, a considerable challenge. Here, we attempt to combat this issue by modulating the innate immune response, targeting formyl peptide receptors (FPRs), G-protein coupled receptors that play key roles in both the regulation and the resolution of the innate inflammatory response. Specifically, we investigated, in vitro, whether Caulerpin—a bis-indole alkaloid isolated from algae of the genus Caulerpa—could act as a molecular antagonist scaffold of FPRs. We showed that Caulerpin significantly reduces the immune response against Hp culture filtrate, by reverting the FPR2-related signaling cascade and thus counteracting the inflammatory reaction triggered by Hp peptide Hp(2–20). Our study suggests Caulerpin to be a promising therapeutic or adjuvant agent for the attenuation of inflammation triggered by Hp infection, as well as its related adverse clinical outcomes.

14 August 2020 in bioRxiv
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Preprint
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VCValeria Cagno
Valeria Cagno
CMChiara Medaglia
Chiara Medaglia
ACAndreas Cerny
Andreas Cerny
TCThomas Cerny
Thomas Cerny
Caroline TapparelCaroline Tapparel
Caroline Tapparel
ECErich Cerny
Erich Cerny
Methylene blue is an FDA and EMA approved drug with an excellent safety profile. It displays broad-spectrum virucidal activity in the presence of UV light and has been shown to be effective in inactivating various viruses in blood products prior to transfusions. In addition, its use has been validated for methemoglobinemia and malaria treatment. Here we show the virucidal activity of methylene blue at low micromolar concentrations and in the absence of UV activation against SARS-CoV2.