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Biagini, G.

Publications and source records attributed to Biagini, G..

6 recordsLinked to original sources
bioRxiv2024

An Accessible 3D HepG2/C3A Liver Spheroid Model Supporting the Complete Intrahepatocytic Lifecycle of Plasmodium falciparum

Current liver-stage Plasmodium falciparum models are complex, expensive, and largely inaccessible, hindering research progress. Here, we show that a 3D liver spheroid model grown from immortalized HepG2/C3A cells supports the complete intrahepatocytic lifecycle of P. falciparum. Our results demonstrate sporozoite infection, development of exoerythrocytic forms, and breakthrough infection into erythrocytes. The 3D-grown spheroid hepatocytes are structurally and functionally polarised, displaying enhanced albumin and urea production and increased expression of key metabolic enzymes, mimicking in vivo conditions - relative to 2D cultures. This accessible, reproducible model lowers barriers to malaria research, promoting advancements in fundamental biology and translational research.

microbiology↗
bioRxiv2024

A mycobacterial DNA extraction protocol designed for resource limited settings generates high quality whole genome sequencing

Mycobacteria are major global human pathogens and include Mycobacterium tuberculosis, the causative agent of tuberculosis, and M. abscessus, an emerging multidrug resistant pathogen. M. abscessus affects people with structural lung disease and those who are immunocompromised, most commonly causing pulmonary disease but also disseminated infections in the central nervous system and skin. High quality whole genome sequencing is essential to research mycobacterial epidemiology, pathogenesis and antimicrobial resistance. However, current DNA extraction protocols are time consuming, use toxic chemicals, require cold chain storage for certain reagents and can often result in poor quality, degraded DNA that directly impacts whole genome sequencing outputs. This is a particular challenge in low-income settings. Here, we report a novel optimised DNA extraction workflow for M. tuberculosis and M. abscessus that invariably generates high quality Illumina short read sequencing data. We evaluated input culture CFU and physical cell disruption times. DNA quantity was determined using a Qubit fluorometer system with DNA integrity assessed using the Agilent TapeStation platform. We showed that this protocol facilitated complete genome assemblies of M. abscessus and M. tuberculosis reference strains. There is no requirement for cold chain transport or storage of reagents, solvent extractions, or boiling to heat inactivate cultures, and the method does not require surfactant chemicals such as cetyltrimethylammonium bromide (CTAB).

microbiology↗
bioRxiv2022

Lack of antiviral activity of probenecid in Vero E6 cells and Syrian golden hamsters: a need for better understanding of inter-lab differences in preclinical assays.

Antiviral interventions are urgently required to support vaccination programmes and reduce the global burden of COVID-19. Prior to initiation of large-scale clinical trials, robust preclinical data in support of candidate plausibility are required. The speed at which preclinical models have been developed during the pandemic are unprecedented but there is a vital need for standardisation and assessment of the Critical Quality Attributes. This work provides cross-validation for the recent report demonstrating potent antiviral activity of probenecid against SARS-CoV-2 in preclinical models (1). Vero E6 cells were pre-incubated with probenecid, across a 7-point concentration range, or control media for 2 hours before infection with SARS-CoV-2 (SARS-CoV-2/Human/Liverpool/REMRQ0001/2020, Pango B; MOI 0.05). Probenecid or control media was then reapplied and plates incubated for 48 hours. Cells were fixed with 4% v/v paraformaldehyde, stained with crystal violet and cytopathic activity quantified by spectrophotometry at 590 nm. Syrian golden hamsters (n=5 per group) were intranasally inoculated with virus (SARS-CoV-2 Delta variant B.1.617.2; 103 PFU/hamster) for 24 hours prior to treatment. Hamsters were treated with probenecid or vehicle for 4 doses. Hamsters were ethically euthanised before quantification of total and sub-genomic pulmonary viral RNAs. No inhibition of cytopathic activity was observed for probenecid at any concentration in Vero E6 cells. Furthermore, no reduction in either total or sub-genomic RNA was observed in terminal lung samples from hamsters on day 3 (P > 0.05). Body weight of uninfected hamsters remained stable throughout the course of the experiment whereas both probenecid- (6 - 9% over 3 days) and vehicle-treated (5 - 10% over 3 days) infected hamsters lost body weight which was comparable in magnitude (P > 0.5). The presented data do not support probenecid as a SARS-CoV-2 antiviral. These data do not support use of probenecid in COVID-19 and further analysis is required prior to initiation of clinical trials to investigate the potential utility of this drug.

pharmacology and toxicology↗
bioRxiv2020

Remdesivir-Ivermectin combination displays synergistic interaction with improved in vitro antiviral activity against SARS-CoV-2

A key element for the prevention and management of COVID-19 is the development of effective therapeutics. Drug combination strategies of repurposed drugs offer several advantages over monotherapies, including the potential to achieve greater efficacy, the potential to increase the therapeutic index of drugs and the potential to reduce the emergence of drug resistance. Here, we report on the in vitro synergistic interaction between two FDA approved drugs, remdesivir and ivermectin resulting in enhanced antiviral activity against SARS-CoV-2. These findings warrant further investigations into the clinical potential of this combination, together with studies to define the underlying mechanism.

microbiology↗
bioRxiv2020

Sequential infection with influenza A virus followed by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) leads to more severe disease and encephalitis in a mouse model of COVID-19.

COVID-19 is a spectrum of clinical symptoms in humans caused by infection with SARS-CoV-2, a recently emerged coronavirus that rapidly caused a pandemic. Coalescence of this virus with seasonal respiratory viruses, particularly influenza virus is a global health concern. To investigate this, transgenic mice expressing the human ACE2 receptor driven by the epithelial cell cytokeratin-18 gene promoter (K18-hACE2) were first infected with IAV followed by SARS-CoV-2. The host response and effect on virus biology was compared to K18-hACE2 mice infected with IAV or SARS-CoV-2 only. Infection of mice with each individual virus resulted in a disease phenotype compared to control mice. Although SARS-CoV-2 RNA synthesis appeared significantly reduced in the sequentially infected mice, they exhibited more rapid weight loss, more severe lung damage and a prolongation of the innate response compared to singly infected or control mice. The sequential infection also exacerbated the extrapulmonary encephalitic manifestations associated with SARS-CoV-2 infection. Conversely, prior infection with a commercially available, multivalent live-attenuated influenza vaccine (Fluenz tetra) elicited the same reduction in SARS-CoV-2 RNA synthesis albeit without the associated increase in disease severity. This suggests that the innate immune response stimulated by infection with IAV is responsible for the observed inhibition of SARS-CoV-2, however, infection with attenuated, apathogenic influenza vaccine does not result in an aberrant immune response and enhanced disease severity. Taken together, the data suggest that the concept of twinfection is deleterious and mitigation steps should be instituted as part of a comprehensive public health response to the COVID-19 pandemic.

microbiology↗