Biology subjects

Mackenzie-Kludas, C.

Publications and source records attributed to Mackenzie-Kludas, C..

4 recordsLinked to original sources

bioRxiv2025

High-stability, clamp-free soluble Sarbecovirus spike trimers and their potential for pan-Sarbecovirus vaccine development.

Broadly effective vaccines are needed to protect against future pandemics caused by severe acute respiratory syndrome coronavirus (SARS CoV)-like coronaviruses (sarbecoviruses). The development of simple trimeric subunit vaccines based on the Sarbecovirus spike (S) has proven problematic due to the unstable nature of the S trimer. Here we developed clamp-free, highly stable soluble S trimers by truncating the stem helix to maximize yield and covalently linking the 3 monomers via engineered disulfides to increase thermostability. In K18hACE2 mice, covalently linked SARS CoV-2 S trimers elicited >10-fold higher neutralizing antibody (NAb) titres than parental unlinked trimers and protected the mice against viral challenge. A trivalent vaccine formulation comprised of covalently stabilized spikes derived from 3 divergent ACE2-using Sarbecovirus clades elicited broad and potent neutralizing activity in mice. The covalently linked S trimers were stable at 37{degrees}C for 112 days and remained intact following lyophilization and storage at ambient temperature for 6 months. This study establishes a framework for producing simple and stable highly immunogenic pan-Sarbecovirus S subunit vaccines that can be stored and distributed in the absence of a cold chain.

microbiology↗

bioRxiv2025

De novo administration of antiviral monoclonal antibodies against SARS-CoV-2 or influenza using mRNA lipid nanoparticles

Monoclonal antibodies (mAbs) are an emerging class of therapeutics for the prevention and treatment of viral infections. Recent advances in mRNA/lipid nanoparticle (LNP) technology provide a potential new modality for the expression of mAbs in vivo, potentially bypassing the need for recombinant manufacturing of mAb proteins. In this study, we compared traditional infusion of neutralising mAbs targeting SARS-CoV-2 or influenza to mRNA-based induction of de novo mAb expression in treated mice. High serum concentrations of mAbs were achieved upon delivery of a single mRNA encoding both heavy and light chains via intravenous or intramuscular routes using prototypic LNP formulations. However, pharmacokinetics were heavily influenced by the induction of anti-drug antibody responses directed against the encoded mAbs, driving reductions in in vivo half-life and compromising protective capacity against SARS-CoV-2 Omicron BA.1 infection. Overall, mRNA/LNP delivery comprises a feasible and attractive pathway to speed the development and deployment of antiviral antibodies, however optimisation of LNP formulation, dosing and administration routes is required to maximise protective potential.

immunology↗

bioRxiv2022

A new concept in antiviral drug design

Contemporary antiviral development, whether by rational drug design or forward pharmacology, primarily strives to produce lock and key inhibitors. While the technology to identify druggable targets and create compounds to bind them has improved dramatically over the last century it has always been constrained by the finite availability of suitable binding sites that antiviral compounds can occupy. Here we present a new approach to drug design that utilizes compounds devised to alter the microenvironment of the virion surface making it incompatible with virus entry and illustrate this strategy with inhibitors of influenza virus. We show that compounds that produce a proton-rich mantle above the virion surface induce a conformational change in the viral hemagglutinin (HA) rendering the virus unable to interact with cellular receptors and gain entry to the cell. The compounds show exceptional antiviral activity both in vitro and in vivo and protect against influenza illness in mice and ferrets after a single dose, either therapeutically or prophylactically. The work presented here lays the foundation for a brand-new category of inhibitors that could be engineered to counter many different viruses and potentially other pathogens.

microbiology↗

bioRxiv2022

Parallel use of pluripotent human stem cell lung and heart models provide new insights for treatment of SARS-CoV-2

SARS-CoV-2 primarily infects the respiratory tract, but pulmonary and cardiac complications occur in severe COVID-19. To elucidate molecular mechanisms in the lung and heart, we conducted paired experiments in human stem cell-derived lung alveolar type II (AT2) epithelial cell and cardiac cultures infected with SARS-CoV-2. With CRISPR- Cas9 mediated knock-out of ACE2, we demonstrated that angiotensin converting enzyme 2 (ACE2) was essential for SARS-CoV-2 infection of both cell types but further processing in lung cells required TMPRSS2 while cardiac cells required the endosomal pathway. Host responses were significantly different; transcriptome profiling and phosphoproteomics responses depended strongly on the cell type. We identified several antiviral compounds with distinct antiviral and toxicity profiles in lung AT2 and cardiac cells, highlighting the importance of using several relevant cell types for evaluation of antiviral drugs. Our data provide new insights into rational drug combinations for effective treatment of a virus that affects multiple organ systems. One-sentence summaryRational treatment strategies for SARS-CoV-2 derived from human PSC models

microbiology↗