Biology subjects

Mallory, M. L.

Publications and source records attributed to Mallory, M. L..

7 recordsLinked to original sources

bioRxiv2026

Broad Sarbecovirus Neutralization by an S2-Directed Plasma Antibody Defines a New Site of Vulnerability in SARS-like Viruses

The repeated emergence of pathogenic coronaviruses highlights the continual threat of zoonotic spillover events and the need to understand conserved regions of the viral spike protein that influence immune recognition. Here, we employ high-resolution proteomic analysis of circulating immunoglobulins to characterize the antibody response to the SARS-CoV-2 spike protein in vaccinated and infected individuals. We recombinantly expressed abundant plasma IgG lineages and identified nine antibodies targeting the highly conserved S2 spike subunit. Most of these S2-reactive plasma mAbs (7 of 9) exhibited neutralizing activity against pangolin coronavirus, while one mAb (SC45) demonstrated potent (IC50 < 1 {micro}g/mL) neutralizing activity against both pangolin and bat sarbecoviruses RsSHC014 and WIV1. Additionally, SC45 exhibited potent prophylactic efficacy in the K18-hACE2 mouse model challenged with Pangolin-Guangdong CoV MP789 (Pg-CoV), significantly reducing lung viral replication at day 4 post-infection. The cryo-EM structure of SC45 bound to the prefusion-stabilized S2 domain of Pg-CoV reveals that SC45 targets a novel, conserved epitope in the connector domain. Strikingly, even though SC45 was the most abundant antibody ([~]13%) of anti-spike plasma IgG in an infected patient and binds to both SARS-CoV-2 and Pg-CoV spike with comparable affinities, it fails to neutralize early (D614G and Omicron BA.1) SARS-CoV-2 variants. Together, these findings identify a conserved site of vulnerability in the spike S2 subunit which informs on potential mechanisms of antibody immunity to zoonotic coronaviruses.

immunology↗

bioRxiv2025

Mouse Adapted Omicron BA.5 Induces A Fibrotic Lung Disease Phenotype in BALB/c Mice

Following SARS-CoV-2 Omicron BA.1, subsequent Omicron sub-lineages have continued to emerge, challenging the development of intervention and prevention strategies, including monoclonal antibodies and vaccines. To better understand the pathogenic effects caused by Omicron BA.5 infection, we developed a mouse-adapted virus with overt disease burden in BALB/c mice. Acute disease was characterized by significant weight loss and lung dysfunction following high-dose challenges. In survivor animals that were followed through 107 days post-infection, subpleural fibrosis with associated tertiary lymphoid structures was noted. Serum from these mice demonstrated potent neutralization against BA.5, with substantially reduced neutralization titers against early epidemic, zoonotic, and more recent contemporary XBB.1.5 variants. Intervention with pre-clinical monoclonal antibodies revealed that robust protection from BA.5-induced lung disease was possible after prophylactic administration. Together, this model enables the investigation of therapeutic approaches for both acute and post-acute sequelae of COVID-19. ImportanceIn order to best combat the evolving landscape of SARS-CoV-2 variants of interest and variants of concern the development of effective small animal models is of critical importance. Herein, we describe the development of a model system in BALB/c mice to study the effects of SARS-CoV-2 BA.5 in both acute and chronic disease manifestations. Intriguingly, we determined that fibrotic lung disease with tertiary lymphoid structures was a prominent feature in the lungs of mice that survived through the acute phase of infection. This is a prominent concern in human patients that survive the initial infection insult. As such, and most critically, the model system presented here provides researchers with an effective pathway in which long COVID manifestations and potential interventions can be studied.

molecular biology↗

bioRxiv2024

Enhanced data collection in the Canadian Arctic for seabird bycatch information yields highly variable results

Incidental catch of seabirds (bycatch) in fisheries has been identified as a major threat to the conservation of seabird populations globally. Acquiring accurate, detailed data on seabird bycatch is an ongoing challenge to effective integrated ecosystem management of commercial fisheries. This is especially true in the Arctic region where different countries have highly variable reporting and data systems to track and understand seabird bycatch in fisheries. To collect detailed data on seabird bycatch in the Greenland halibut (Reinhardtius hippoglossoides) fishery in northern Canada, we applied two methods that asked for more information than standardly reported in the fishery as a voluntary effort with industry partners. We found that the amount of bird bycatch reported in both enhanced datasheets completed by at-sea observers (ASO) and carcass collections yielded different results when compared to the typical seabird bycatch reporting in the fisheries ASO database. Across three years of data collection (2016, 2018, and 2019), the number of seabirds reported using the enhanced data collection methods were 0.5-11-fold the number from typical ASO database values. In a fourth year of observations (2023), enhanced datasheets from the ASO reported no bycaught fulmars (gulls and terns were reported), but the accompanying photographs showed northern fulmars as bycatch, further supporting that seabird identification is hampering accurate reporting. We then used these data to model how the differences between data sources may fluctuate across years. These large discrepancies between the methods highlight the challenges with obtaining accurate and precise seabird bycatch data needed to implement a meaningful ecosystem approach to the management of the fisheries. Future modelling efforts need to take these differing data sources and variability into account to fully understand the potential population level impacts of fisheries on seabird populations.

ecology↗

bioRxiv2023

Extremely potent pan-sarbecovirus neutralizing antibodies generated by immunization of macaques with an AS03-adjuvanted monovalent subunit vaccine against SARS-CoV-2

The rapid emergence of SARS-CoV-2 variants that evade immunity to vaccination has placed a global health imperative on the development of therapeutic countermeasures that provide broad protection against SARS-CoV-2 and related sarbecoviruses. Here, we identified extremely potent pan-sarbecovirus antibodies from non-human primates vaccinated with an AS03 adjuvanted subunit vaccine against SARS-CoV-2 that recognize conserved epitopes in the receptor binding domain (RBD) with femtomolar affinities. Longitudinal analysis revealed progressive accumulation of somatic mutation in the immunoglobulin genes of antigen-specific memory B cells for at least one year following primary vaccination. 514 monoclonal antibodies (mAbs) were generated from antigen-specific memory B cells. Antibodies isolated at 5 to 12 months following vaccination displayed greater potency and breadth, relative to those identified at 1.4 months. Notably, 15 out of 338 ([~]4.4%) antibodies isolated at 1.4[~]6 months after the primary vaccination showed extraordinary neutralization potency against SARS-CoV-2 omicron BA.1, despite the absence of BA.1 neutralization in serum. Two of them, 25F9 and 20A7, neutralized authentic clade Ia sarbecoviruses (SARS-CoV, WIV-1, SHC014) and clade Ib sarbecoviruses (SARS-CoV-2 D614G, SARS-CoV-2 BA.1, Pangolin-GD) with half-maximal inhibition concentrations of (0.85 ng/ml, 3 ng/ml, 6 ng/ml, 6 ng/ml, 42 ng/ml, 6 ng/ml) and (13 ng/ml, 2 ng/ml, 18 ng/ml, 9 ng/ml, 6 ng/ml, 345 ng/ml), respectively. Furthermore, 20A7 and 27A12 showed potent neutralization against all SARS-CoV-2 variants of concern and multiple Omicron sublineages, including BA.1, BA.2, BA.3, BA.4/5, BQ.1, BQ.1.1 and XBB variants. X-ray crystallography studies revealed the molecular basis of broad and potent neutralization through targeting conserved RBD sites. In vivo prophylactic protection of 25F9, 20A7 and 27A12 was confirmed in aged Balb/c mice. Notably, administration of 25F9 provided complete protection against SARS-CoV-2, SARS-CoV-2 BA.1, SARS-CoV, and SHC014 challenge, underscoring that these mAbs are promising pan-sarbecovirus therapeutic antibodies. One Sentence SummaryExtremely potent pan-sarbecovirus neutralizing antibodies

immunology↗

bioRxiv2021

Thiol-based mucolytics exhibit antiviral activity against SARS-CoV-2 through allosteric disulfide disruption in the spike glycoprotein

Small molecule therapeutics targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have lagged far behind the development of vaccines in the fight to control the COVID-19 pandemic. Here, we show that thiol-based mucolytic agents, P2119 and P2165, potently inhibit infection by human coronaviruses, including SARS-CoV-2, and decrease the binding of spike glycoprotein to its receptor, angiotensin-converting enzyme 2 (ACE2). Proteomics and reactive cysteine profiling link the antiviral activity of repurposed mucolytic agents to the reduction of key disulfides, specifically, by disruption of the Cys379-Cys432 and Cys391-Cys525 pairs distal to the receptor binding motif (RBM) in the receptor binding domain (RBD) of the spike glycoprotein. Computational analyses provide insight into conformation changes that occur when these disulfides break or form, consistent with an allosteric role, and indicate that P2119/P2165 target a conserved hydrophobic binding pocket in the RBD with the benzyl thiol warhead pointed directly towards Cys432. These collective findings establish the vulnerability of human coronaviruses to repurposed thiol-based mucolytics and lay the groundwork for developing these compounds as a potential treatment, preventative and/or adjuvant against infection.

microbiology↗

bioRxiv2021

SARS-CoV-2 Vaccines Elicit Durable Immune Responses in Infant Rhesus Macaques

Early life SARS-CoV-2 vaccination has the potential to provide lifelong protection and achieve herd immunity. To evaluate SARS-CoV-2 infant vaccination, we immunized two groups of 8 infant rhesus macaques (RMs) at weeks 0 and 4 with stabilized prefusion SARS-CoV-2 S-2P spike (S) protein, either encoded by mRNA encapsulated in lipid nanoparticles (mRNA-LNP) or mixed with 3M-052-SE, a TLR7/8 agonist in a squalene emulsion (Protein+3M-052-SE). Neither vaccine induced adverse effects. High magnitude S-binding IgG and neutralizing infectious dose 50 (ID50) >103 were elicited by both vaccines. S-specific T cell responses were dominated by IL-17, IFN-{gamma}, or TNF-. Antibody and cellular responses were stable through week 22. The S-2P mRNA-LNP and Protein-3M-052-SE vaccines are promising pediatric SARS-CoV-2 vaccine candidates to achieve durable protective immunity. One-Sentence SummarySARS-CoV-2 vaccines are well-tolerated and highly immunogenic in infant rhesus macaques

immunology↗

bioRxiv2020

Complex population structure of the Atlantic puffin revealed by whole genome analyses

The factors underlying gene flow and genomic population structure in vagile seabirds are notoriously difficult to understand due to their complex ecology with diverse dispersal barriers and extensive periods at sea. Yet, such understanding is vital for conservation management of seabirds that are globally declining at alarming rates. Here, we elucidate the population structure of the Atlantic puffin (Fratercula arctica) by assembling its reference genome and analyzing genome-wide resequencing data of 72 individuals from 12 colonies. We identify four large, genetically distinct clusters, observe isolation-by-distance between colonies within these clusters, and obtain evidence for a secondary contact zone. These observations disagree with the current taxonomy, and show that a complex set of contemporary biotic factors impede gene flow over different spatial scales. Our results highlight the power of whole genome data to reveal unexpected population structure in vagile marine seabirds and its value for seabird taxonomy, evolution and conservation.

genomics↗