Biology subjects

Joyce, C.

Publications and source records attributed to Joyce, C..

11 recordsLinked to original sources

bioRxiv2026

A ML-framework for the discovery of next-generation IBD targets using a harmonized single-cell atlas of patient tissue

Target discovery for IBD has traditionally relied on genetic associations, which lack the cellular resolution needed to identify novel, actionable, cell type-specific disease pathways. Here, we describe an integrated analytical and experimental framework that leverages harmonized single-cell data to systematically discover novel therapeutic strategies for IBD. We used AMICA DBTM, Immunais harmonized database of single-cell RNA datasets to construct a harmonized 1 million single-cell atlas of the human intestine. We applied a machine learning framework (Immune Patient Representation, IPR) to identify disease-associated transcriptional programs and cell type-specific gene targets. Candidate targets were prioritized using atlas-derived metrics, refined using custom criteria emphasizing translational actionability, and validated across independent clinical cohorts. Select candidates were evaluated in human primary-cell models reflecting the targets cell-type context. The IPR framework identified 85 disease-associated transcriptional programs and ranked 400 cell type-specific target genes across immune and stromal lineages. Disease-associated programs were interpreted using a structured AI-assisted reasoning framework for structured biological reasoning, linking them to IBD-relevant pathways and guiding the identification of novel, promising gene targets. Functional validation of two cell-type-specific candidates, PTGIR in myeloid cells and IL6ST in fibroblasts, confirmed the reduction of inflammatory and fibrotic pathways linked to IBD pathology. Multi-omic profiling and projection of in vitro phenotypes to patient datasets demonstrated the reversal of disease-associated programs via mechanisms distinct from those of existing biologics. Our single-cell anchored, machine-learning framework integrates in silico discovery with experimental validation, revealing new cell type-specific therapeutic opportunities and supporting a scalable approach for precision target discovery in IBD and other immune-mediated diseases.

bioinformatics↗

bioRxiv2025

Engineering HIV antibodies with enhanced breadth and potency of neutralization through multistate affinity maturation

Broadly neutralizing antibodies (bnAbs) against HIV hold promise as therapeutic and prophylactic agents, but realizing this potential requires antibodies that function across the antigenic heterogeneity of the HIV envelope glycoprotein (Env). Although numerous bnAbs have been isolated from infected individuals, their breadth and potency may not be sufficient to tackle global viral diversity, motivating efforts to further improve their neutralization capacity. Here, we address this challenge using a multistate antibody engineering approach integrating deep mutational scanning with combinatorial library screening across diverse Env variants. This strategy enables identification of mutation patterns that confer improved binding across antigenically distinct targets. Starting from one of the best-in-class CD4-binding site bnAbs, we performed iterative optimization to increase binding affinity across diverse Env variants. The resulting lead candidate exhibited improved breadth and up to 100-fold higher potency against pseudoviruses from large cross-clade historical and contemporary panels while maintaining biophysical and pharmacokinetic profiles conducive to clinical development. Structural and molecular dynamics analyses revealed a unique tri-tyrosine aromatic triad and reinforced electrostatic contacts that stabilized the bnAb/Env interface. These findings demonstrate that systematic in vitro engineering can generate bnAbs with enhanced breadth and potency, providing a generalizable strategy for developing therapeutic antibodies against highly diverse pathogens.

bioengineering↗

bioRxiv2025

Longitudinal analysis of drift in the circulating human antibody repertoire over four years

The human immune system is a sophisticated network of cells and molecules that plays a vital role in safeguarding the body against a broad range of foreign agents. One of the key components of the immune system is the circulating antibody repertoire, a vast collection of different antibodies that recognize and eliminate foreign agents specifically. The diversity and specificity of the circulating antibody repertoire are essential for effective immunity. In a study of ten healthy donors, we previously demonstrated the accessible human antibody repertoire to be on the order of 1015-1018 distinct members, although an individual will only sample a fraction of that repertoire at a given time point. The mode of generation of the naive antibody repertoire through random recombination before antigen contact suggests that the composition of the circulating antibody repertoire may drift over time, but the magnitude of this drift is poorly understood. Here, we used high-throughput sequencing to analyze two donors from our original study, approximately four years later. Our results reveal conservation of the size, overall diversity, and gross features of the circulating antibody repertoire, such as V- and J-gene usage and CDRH3 length distribution, over time but suggest substantial changes to fine features of the repertoire, such as combinations of V, J, D gene segments and P and N sequences, which may influence primary responses to newly encountered pathogens as well as to immunization procedures.

immunology↗

bioRxiv2024

Immunization of cows with HIV envelope trimers generates broadly neutralizing antibodies to the V2-apex from the ultralong CDRH3 repertoire

The generation of broadly neutralizing antibodies (bnAbs) to specific HIV epitopes of the HIV Envelope (Env) is one of the cornerstones of HIV vaccine research. The current animal models we use have been unable to reliable produce a broadly neutralizing antibody response, with the exception of cows. Cows have rapidly and reliably produced a CD4 binding site response by homologous prime and boosting with a native-like Env trimer. In small animal models other engineered immunogens previously have been able to focus antibody responses to the bnAb V2-apex region of Env. Here, we immunized two groups of cows (n=4) with two regiments of V2-apex focusing immunogens to investigate whether antibody responses could be directed to the V2-apex on Env. Group 1 were immunized with chimpanzee simian immunodeficiency virus (SIV)-Env trimer that shares its V2-apex with HIV, followed by immunization with C108, a V2-apex focusing immunogen, and finally boosted with a cross-clade native-like trimer cocktail. Group 2 were immunized with HIV C108 Env trimer followed by the same HIV trimer cocktail as Group 1. Longitudinal serum analysis showed that one cow in each group developed serum neutralizing antibody responses to the V2-apex. Eight and 11 bnAbs were isolated from Group 1 and Group 2 cows respectively. The best bnAbs had both medium breadth and potency. Potent and broad responses developed later than previous CD4bs cow bnAbs and required several different immunogens. All isolated bnAbs were derived from the ultralong CDRH3 repertoire. The finding that cow antibodies can target multiple broadly neutralizing epitopes on the HIV surface reveals important insight into the generation of immunogens and testing in the cow animal model. The exclusive isolation of ultralong CDRH3 bnAbs, despite only comprising a small percent of the cow repertoire, suggests these antibodies outcompete the long and short CDRH3 antibodies during the bnAb response. Author SummaryThe elicitation of epitope-specific broadly neutralizing antibodies is highly desirable for an HIV vaccine as bnAbs can prevent HIV infection in robust animal challenge models and humans, but to date, cows are the only model shown to reliably produce HIV bnAb responses on Envelope (Env) immunization. These responses involve Abs with ultralong CDRH3s and are all directed to a single site, the CD4 binding site. To determine whether this is a unique phenomenon or whether cow antibodies can target further bnAb sites on Env, we employed an immunization protocol that generated cow bnAbs to a second site, the V2-apex. We conclude that ultralong CDRH3s are well adapted to penetrate the glycan shield of HIV Env and recognize conserved regions and may constitute protein units, either in the context of antibodies or in other engineered proteins, that could be deployed as anti-HIV reagents.

immunology↗

bioRxiv2023

Germline-targeting chimpanzee SIV Envelopes induce V2-apex broadly neutralizing-like B cell precursors in a rhesus macaque infection model

Eliciting broadly neutralizing antibodies-(bnAbs) remains a major goal of HIV-1 vaccine research. Previously, we showed that a soluble chimpanzee SIV Envelope-(Env) trimer, MT145K, bound several human V2-apex bnAb-precursors and stimulated an appropriate response in V2-apex bnAb precursor-expressing knock-in mice. Here, we tested the immunogenicity of three MT145 variants (MT145, MT145K, MT145K.dV5) expressed as chimeric simian-chimpanzee-immunodeficiency-viruses-(SCIVs) in rhesus macaques-(RMs). All three viruses established productive infections with high setpoint vRNA titers. RMs infected with the germline-targeting SCIV_MT145K and SCIV_MT145K.dV5 exhibited larger and more clonally expanded B cell lineages featuring long anionic heavy chain complementary-determining-regions-(HCDR3s) compared with wildtype SCIV_MT145. Moreover, antigen-specific B cell analysis revealed enrichment for long-CDHR3-bearing antibodies in SCIV_MT145K.dV5 infected animals with paratope features resembling prototypic V2-apex bnAbs and their precursors. Although none of the animals developed bnAbs, these results show that germline-targeting SCIVs can activate and preferentially expand B cells expressing V2-apex bnAb-like precursors, the first step in bnAb elicitation. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=180 HEIGHT=200 SRC="FIGDIR/small/558743v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@17673c8org.highwire.dtl.DTLVardef@1ab61a8org.highwire.dtl.DTLVardef@98781forg.highwire.dtl.DTLVardef@1f63e9b_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2023

B cell repertoire sequencing of HIV-1 pediatric elite-neutralizers identifies multiple broadly neutralizing antibody clonotypes

A limited subset of HIV-1 infected adult individuals typically after at least 2-3 years of chronic infection, develop broadly neutralizing antibodies (bnAbs), suggesting that highly conserved neutralizing epitopes on the HIV-1 envelope glycoprotein are difficult for B cell receptors to effectively target, during natural infection. Recent studies have shown the evolution of bnAbs in HIV-1 infected infants. We used bulk BCR sequencing (BCR-seq) to profile the B cell receptors from longitudinal samples (3 time points) collected from a rare pair of antiretroviral-naive, HIV-1 infected pediatric monozygotic twins (AIIMS_329 and AIIMS_330) who displayed elite plasma neutralizing activity against HIV-1. BCR-seq of both twins revealed convergent antibody characteristics including V-gene use, CDRH3 lengths and somatic hypermutation (SHM). Further, antibody clonotypes with genetic features similar to highly potent bnAbs isolated from adults showed ongoing development in donor AIIMS_330 but not in AIIMS_329, corroborating our earlier findings based on plasma bnAbs responses. An increase in SHM was observed in sequences of the IgA isotype from AIIMS_330. This study suggests that children living with chronic HIV-1 can develop clonotypes of HIV-1 bnAbs against multiple envelope epitopes similar to those isolated from adults, highlighting that such B cells could be steered to elicit bnAbs responses through vaccines aimed to induce bnAbs against HIV-1 in a broad range of people including children.

immunology↗

bioRxiv2021

The chemical synthesis of knob domain antibody fragments

Cysteine-rich knob domains found in the ultralong complementarity determining regions of a subset of bovine antibodies, are capable of functioning autonomously as 3-6 kDa peptides. While they can be expressed recombinantly in cellular systems, in this paper we show that knob domains are also readily amenable to chemical synthesis, with a co-crystal structure of a chemically synthesised knob domain in complex with antigen showing structural equivalence to the biological product. For drug discovery, following immunisation of cattle, knob domain peptides can be synthesised directly from antibody sequence data, combining the power and diversity of the bovine immune repertoire with the ability to rapidly incorporate non-biological modifications. We demonstrate that, through rational design with non-natural amino acids, paratope diversity can be massively expanded, in this case improving the efficacy of an allosteric peptide. As a potential route to further improve stability, we also performed head-to-tail cyclisation, exploiting the unusual proximity of the N- and C-termini to synthesise functional, fully cyclic antibody fragments. Lastly, we highlight the stability of knob domains in plasma and, through pharmacokinetic studies, use palmitoylation as a route to extend the plasma half-life of knob domains in vivo. This study presents an antibody-derived medicinal chemistry platform, with protocols for solid-phase synthesis of knob domains; together with characterisation of their molecular structures, in vitro pharmacology and pharmacokinetics.

biochemistry↗

bioRxiv2021

Broadening a SARS-CoV-1 neutralizing antibody for potent SARS-CoV-2 neutralization through directed evolution

The emergence of SARS-CoV-2 underscores the need for strategies to rapidly develop neutralizing monoclonal antibodies that can function as prophylactic and therapeutic agents and to help guide vaccine design. Here, we demonstrate that engineering approaches can be used to refocus an existing neutralizing antibody to a related but resistant virus. Using a rapid affinity maturation strategy, we engineered CR3022, a SARS-CoV-1 neutralizing antibody, to bind SARS-CoV-2 receptor binding domain with >1000-fold improved affinity. The engineered CR3022 neutralized SARS-CoV-2 and provided prophylactic protection from viral challenge in a small animal model of SARS-CoV-2 infection. Deep sequencing throughout the engineering process paired with crystallographic analysis of an enhanced antibody elucidated the molecular mechanisms by which engineered CR3022 can accommodate sequence differences in the epitope between SARS-CoV-1 and SARS-CoV-2. The workflow described provides a blueprint for rapid broadening of neutralization of an antibody from one virus to closely related but resistant viruses.

bioengineering↗

bioRxiv2021

Assessment of the pollution incident performance of water and sewerage companies in England

Comparison of water and sewerage company pollution performance in relation to severity, frequency and self-reporting of pollution incidents is made difficult by differences in environmental and operational conditions. In England, the deterioration in pollution incident performance across the water industry, makes it important to investigate common trends that could be addressed at national and regional levels. Yet, to date there has been no external peer-reviewed analysis of national pollution incident data in England. This project aimed to analyse available pollution incident data to assess and compare the performance of water and sewerage companies in England. Results indicated that there was significant variation in pollution incident numbers and the severity of the impact on the water environment for different asset types (operational property of the water and sewerage company such as a sewage treatment works). Increasing numbers of pollution incidents from pumping stations and sewage treatment works, were largely responsible for overall increases in pollution incidents. The highest increase in pollution incidents in 2019, was observed from pumping stations. Variation was evident in company self-reporting percentages across asset types. There were significant positive relationships between the self-reporting percentages of pollution incidents and total numbers of reported pollution incidents per 10,000 km sewer length for pumping stations and sewage treatment works. These results indicate that in at least these asset types, an estimated 5% of pollution incidents could go unreported, if not self-reported by the company. Pollution events not reported quickly by companies, can lead to more severe impacts to the water environment so rapid and consistent reporting of incidents is crucial for limiting damage. The results have significance for the water industry internationally, because the issues presented here are not restricted to England. Whilst this research highlighted a number of key areas for more detailed analysis, in the short-term, research should focus on investigating best practice for reporting pollution incidents. It is important to get an accurate baseline of the number of pollution incidents and whether a proportion are currently going unreported. This research should seek to aid the standardisation of reporting practice across the water industry.

ecology↗

bioRxiv2019

Comparisons of the antibody repertoires of a humanized rodent and humans by high throughput sequencing

The humanization of animal model immune systems by genetic engineering has shown great promise for antibody discovery, tolerance studies and for the evaluation of vaccines. Assessment of the baseline antibody repertoire of unimmunized model animals will be useful as a benchmark for future immunization experiments. We characterized the heavy chain and kappa chain antibody repertoires of a model animal, the OmniRat, by high throughput antibody sequencing and made use of two novel datasets for comparison to human repertoires. Intra-animal and inter-animal repertoire comparisons reveal a high level of conservation in antibody diversity between the lymph node and spleen and between members of the species. Multiple differences were found in both the heavy and kappa chain repertoires between OmniRats and humans including gene segment usage, CDR3 length distributions, class switch recombination, somatic hypermutation levels and in features of V(D)J recombination. The Inference and Generation of Repertoires (IGoR) software tool was used to model recombination in VH regions which allowed for the quantification of some of these differences. Diversity estimates of the OmniRat heavy chain repertoires almost reached that of humans, around two orders of magnitude less. Despite variation between the species repertoires, a high frequency of OmniRat clonotypes were also found in the human repertoire. These data give insights into the development and selection of humanized animal antibodies and provide actionable information for use in vaccine studies.

immunology↗

bioRxiv2019

Female lower urinary tract microbiota do not correspond to IC/PBS symptoms: a case-controlled study

ABSTRACTO_ST_ABSOBJECTIVEC_ST_ABSCurrent etiology of interstitial cystitis/painful bladder syndrome (IC/PBS) is poorly understood and multifactorial. Recent studies suggest the female urinary microbiota (FUM) contribute to IC/PBS symptoms. This study was designed to determine if the FUM, analyzed using mid-stream voided urine samples, differs between IC/PBS patients and controls.\n\nMATERIALS AND METHODSThis prospective case-controlled study compared the voided FUM of women with symptoms of urinary frequency, urgency, and bladder pain for greater than 6 months to the voided FUM of healthy female controls without pain. Bacterial identification was performed using 16S rRNA gene sequencing and EQUC, a validated enhanced urine culture approach. Urotype was defined by a genus present at >50% relative abundance. If no genus was present above this threshold, the urotype was classified as mixe. Chi-square and Fishers exact tests were performed. P-values <0.05 were considered significant.\n\nRESULTSA mid-stream voided specimen was collected from 21 IC/PBS patients and 20 asymptomatic controls. Both groups had similar demographics. Urotypes did not differ between cohorts as assessed by either EQUC or 16S rRNA gene sequencing. We detected no significant differences between cohorts in terms of alpha-diversity. Cohorts also were not distinct using Principle Component Analysis or hierarchical clustering. Detection by EQUC of bacterial species considered uropathogenic was high in both cohorts, but detection of these uropathogenic species did not differ between groups (p=0.10).\n\nCONCLUSIONSEnhanced culture and modern DNA sequencing methods provide evidence that IC/PBS symptoms may not be related to differences in the FUM, at least not its bacterial components. Future larger studies are needed to confirm this preliminary finding.

microbiology↗