Conference Agenda

Ascaris spp. infect approximately 804 million people, causing substantial malnutrition, stunting and morbidity in school-aged children in low-income populations, exceeding 750,000 Disability Adjusted Life-Years annually. Current single-dose oral anthelmintics offer no sustained protection nor interruption of transmission. Interventions that prevent infection are needed. During early infection, Ascaris larvae migrate from the host intestine to the liver and lung before maturation in the small intestine. This process is thought to be passively directed by host blood flow; however, multiple studies suggest active chemotaxis. Here, we use larval agar migration assays and microfluidic chemotaxis arenas to demonstrate that freshly-hatched Ascaris suum larvae exhibit liver-specific chemotaxis in vitro, including increased migration distance, speed, and directional movement toward liver gradients, and reduced turning behaviours, relative to lung or RPMI controls. These responses coincided with specific transcriptional up-regulation of chemotaxis receptors, signalling markers and metabolic pathways in liver relative to lung or RPMI. Our findings provide strong evidence of organ-specific, active chemotaxis in Ascaris infection, with implications for other major human helminthiases, and identify conserved chemosensory pathways as promising therapeutic targets. Disrupting chemosensory-guided navigation could prevent larval migration, offering a novel strategy to combat ascariasis.

RNA-binding proteins (RBPs) regulate splicing, RNA silencing, and translational repression in eukaryotes. Many are conserved from yeast to humans but are absent or rudimentary in prokaryotes, suggesting an early emergence of “eukaryotic-innovative” RBPs. We hypothesised that these RBPs arose long before yeast and are retained in Giardia, an early-diverging eukaryote. To test this, we built a phylogenomic atlas of RBP families across the tree of life and analysed domain topology, domain co-occurrence, and intrinsically disordered regions (IDRs) to define their architectural evolution. We then characterised the Giardia RBPome using domain- and structure-informed annotation integrated with transcriptomics, proteomics, and RNA–protein interactome capture to identify canonical and non-canonical (“moonlighting”) RBPs. Direct RNA targets and regulatory networks of representative eukaryotic-innovative RBPs, including PUF, DDX3X, EIF4A, and PGK, were resolved using enhanced CLIP-seq and RBP immunoprecipitation. Functional significance was assessed by CRISPRi-based genetics, and condensate behaviour was tested using phase-separation assays in vitro and in vivo. Our analyses show that multiple eukaryotic-innovative RBPs are already present in Giardia, with simplified but functional architectures, conserved RNA–protein networks, regulatory phenotypes, and condensate-like behaviour, establishing Giardia as a minimal model for the earliest evolution of eukaryotic post-transcriptional control.

Giardia duodenalis is a gastrointestinal parasite causing ~200 million symptomatic infections annually, disproportionately in lower socioeconomic tiers and children. Chemotherapeutic interventions are limited to nitroheterocyclic antibiotics such as metronidazole. However, high doses are toxic and drug-resistant treatment failures occur in up to 20% of cases, highlighting the urgency of novel and safer chemotherapeutics. Here, we target the disproportionate kinome of G. duodenalis with small-molecule inhibitors to reveal novel antigiardials and their molecular targets for next generation antiparasitics.

Using "Click" chemistry, we immobilised a potent drug-like kinase inhibitor to azide-agarose supports and identified a high-affinity kinase domain-containing protein (GiK5) as the putative target for this inhibitor. We validated recombinant GiK5-inhibitor engagement through differential scanning fluorimetry, native mass spectrometry and the fluorescent ADP-glo assay. Further, we conducted a multiplexed CRISPR-interference knockdown which showed lower GiK5 abundance at the protein level contributed to slower parasite growth, suggesting the likely essentiality of this protein in the parasite.

We reveal this likely druggable kinase in G. duodenalis and this workflow incentivises high-throughput, target-centric screening campaigns for structure-guided drug-discovery, as well as repurposing clinically-approved kinase inhibitors for chemotherapeutic interventions against this parasite.

Programmed cell death (apoptosis) is a fundamental process in metazoans, extensively characterised in vertebrates but comparatively understudied in invertebrates beyond the model organisms Caenorhabditis elegans and Drosophila melanogaster. Here, we present the first reconstruction of the intrinsic apoptosis pathway in the parasitic nematode Haemonchus contortus, a blood-feeding pathogen of ruminants responsible for substantial global production losses. Using C. elegans proteins as a reference, we integrated genome-wide homology searches with structural modelling and developmental transcriptomic and proteomic analyses to identify apoptosis regulators in H. contortus. Homologues of all canonical pathway components were identified, including CEP-1, EGL-1, CED-9, CED-4 and CED-3, together with modulators such as DRE-1 and PUF-8. Structural analyses revealed conservation of key interaction complexes (CED-9:CED-4 and CED-4:CED-3), whereas EGL-1 and CEP-1 retained critical structural domains despite marked sequence divergence. Transcriptomic profiling showed that Hc-ced-9 and Hc-ced-3 are constitutively expressed across developmental stages, whereas Hc-cep-1 and Hc-egl-1 display stage-specific transcription. Proteomic data confirmed the presence of Hc-CED-9, Hc-CED-4 and Hc-CED-3 in at least one life stage but did not detect Hc-EGL-1 or Hc-DRE-1. Discordances between transcript and protein abundance, particularly for Hc-EGL-1, suggest post-transcriptional regulation. Future efforts are needed to elucidate the apoptosis pathway across members of the phylum Nematoda.

Intrinsic apoptosis is a form of programmed cell death that governs development, tissue homeostasis and stress responses in animals. In nematodes, the pathway was first genetically defined in the free-living nematode Caenorhabditis elegans, yet how it has diversified and operates across the phylum, which encompasses parasites of humans and animals spanning clades I–V, remains poorly resolved. Here, we synthesise genomic, structural and functional data to establish a framework for intrinsic apoptosis in nematodes. Although the core CED-9-CED-4-CED-3 module is retained, its developmental deployment and regulatory processes remain largely uncharacterised beyond C. elegans. Unlike the corresponding BCL-2-regulated apoptotic pathway in vertebrates, C. elegans lacks a canonical BAX/BAK-driven mitochondrial permeabilisation system, and whether comparable mitochondrial amplification mechanisms operate in other nematodes remains unclear, particularly in species encoding multiple CED-9/BCL-2-like proteins. This alternative regulatory configuration, coupled with structural divergence of nematode CED-9 and CED-4-like proteins from their vertebrate orthologues, suggests a distinctive evolutionary trajectory for apoptotic regulation in nematodes. By integrating biological with emerging structural insights, we define a foundation for studying apoptosis across clades I–V and assess its potential for anthelmintic target discovery.

Schistosomiasis-induced fibrosis, driven by host immune response to trapped eggs, is the principal cause of pathology and schistosomiasis-related morbidity. While praziquantel effectively clears adult parasites, no therapies exist to target egg or egg-induced tissue fibrosis. To address gaps in fibrosis-related cellular mechanisms and identify novel antifibrotic targets, we used single-cell spatial transcriptomics with a 5000-gene mouse panel to map the molecular architecture of hepatic and intestinal fibrotic regions in Schistosoma mansoni-infected mice. Results showed that schistosome-induced granulomas are highly organized and overlap with fibrotic regions in both tissues at 8 weeks post-infection. Differential expression analysis identified 1175 genes in 534k liver cells and 807 genes in 259k intestine cells significantly altered between healthy control and infected samples. These DEGs are strongly associated with cytokine and interleukin signaling, TGF‑β pathway, and extracellular matrix organization. The cell types enriched in infected regions included macrophages, collagen-producing cells (liver-activated hepatic stellate cells, intestine-activated fibroblasts), eosinophil-like cells, T, B, and plasma cells. Furthermore, cell-cell interaction analysis revealed strong interactions between macrophages and collagen-producing cells in infected tissues. While many identified ligand-receptor pairs are organ-specific, a core signature of 5 pairs (including Col1a2/Tgm2-Itgb1) was shared across tissues, representing potential pan-tissue therapeutic targets for schistosome-induced fibrosis.

Alternative splicing is a major mediator of eukaryotic gene expression, operating co-transcriptionally and post-transcriptionally to influence cellular function, development, and differentiation. During alternative splicing, trans-acting factors interact with cis-elements within pre-mRNA transcripts to produce divergent proteoforms. In eukaryotes, mosttrans-acting factors work in conjunction as the spliceosome, a dynamic ribonucleoprotein complex comprised of catalytic RNAs and hundreds of proteins. Previous studies sought to comprehend the intricate mechanisms of the spliceosome within a simplistic system, utilising the model organism Saccharomyces cerevisiae. However, there exists a eukaryote more basal than yeast – Giardia duodenalis, an intron-poor enteric parasite, evolved over 500 million years earlier. Our bioinformatic analyses indicated that splicing proteins in Giardia are minimal, both in number and structure. This raises the question: In deeply-branching eukaryotes such as Giardia, does splicing occur spliceosomally or via a more primordial method? To understand the system of splicing in Giardia, we conducted an in vitro splicing assay involving both conventional and chimeric intron-containing transcripts. In parallel, we established a nuclear proteome to locate and validate the suite of Giardia splicing proteins. By implementing a multiomic approach, our study offers a glimpse into the origins and evolution of alternative splicing following the inception of eukaryotic life.