Join our online ASP Seminar Series Friday 17 April @1pm AEST, featuring Meghan Zadow, The University of Adelaide, presenting “Complementary proteomics approaches for identification of interacting partners and function of the Plasmodium falciparum regulatory protein Alba4″ and Hayley DeCristi, The University of Sydney presenting”Growth and development of Fasciola hepatica on an in vitro 3D cell culture model: how does it compare to in vivo?” with co-chairs Ben Liffner, University of Adelaide and Grace Peters, University of New South Wales.
Meghan is a final-year PhD candidate at Adelaide University where she investigates proteins controlling replication, transcription, and translation in the malaria-causing parasite Plasmodium falciparum. Her research combines gene-editing and proteomics approaches to characterise the protein interaction networks of target proteins and uncover their roles during parasite blood stage development. Meghan is also passionate about developing novel molecular tools and experimental approaches to study divergent organisms like Plasmodium, where available methodologies and resources often lag behind those of model systems. Meghan’s seminar is also highlighting World Malaria Day 2026.
Abstract: Complementary proteomics approaches for identification of interacting partners and function of the Plasmodium falciparum regulatory protein Alba4
Meghan E. Zadow1,2*, Ghizal Siddiqui3, Joshua P. Morrow3, Yijia Ji3, Darren J. Creek3, Christopher A. MacRaild3 and Danny W. Wilson1,2,4
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, South Australia,
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide 5005, South Australia,
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia,
- Burnet Institute, Melbourne 3004, Victoria, Australia.
Plasmodium spp. parasites have distinct lifecycle stages requiring strict gene and protein regulation for stage transition and survival. Surprisingly, malaria and related parasites appear to a have a reduced complement of transcriptional regulators, indicating that expanded families of post-transcriptional regulators such as the Alba (Acetylation lowers binding affinity) are key elements of regulatory processes. Here, we utilised gene-editing and complementary proteomics approaches to understand the protein interaction network and function of PfAlba4 in late blood stage Plasmodium falciparum parasites. Using an established episomally expressed miniTurbo-BioID system, proteins in close proximity to PfAlba4 were biotin labelled, isolated and then identified with mass spectrometry, leading to the identification of >50 high-confidence potential protein interactors of PfAlba4 with ~23% of these being of unknown function. As secondary confirmation of the proximity interactome for PfAlba4, we applied and validated a custom-built Split-TurboID system designed to minimise cellular-toxicity from the biotinylating enzyme, which demonstrated >23% overlap in high confidence potential PfAlba4 interactors. A gene-edited parasite line was then generated for one of the proteins identified in both BioID datasets (PF3D7_0706500) and utilised for co-immunoprecipitation experiments that supported a direct interaction of PF3D7_0706500 with PfAlba4. Gene ontology and K means clustering analysis using the string database revealed an enrichment of interacting proteins involved in the negative regulation of translation – including the CCR4-NOT complex, Eukaryotic translation initiation factor 4F complex, and proteins associated with nuclear-transcribed mRNA catabolism/nonsense-mediated decay – for both PfAlba4 and its putative interacting partner PF3D7_0706500. Together, these data suggest PfAlba4 is a key regulator of mRNA translation and decay during malaria parasite blood stage development. The gene-edited lines and high-quality preliminary interactome developed in this study will enable characterisation of PfAlba4’s essential cell regulatory function and potentially identify additional key regulatory proteins that could be targets for antimalarial development.
Hayley DeCristi, from Florida, USA, has dedicated her career to the fields of animal science and health. She completed a Bachelor of Science at the University of South Florida majoring in Integrative Animal Biology in May 2022, before immersing herself in hands-on experience. Hayley has worked in a kennel for three years and served as a veterinary technician for one year, honing her skills and deepening her understanding of animal care. In 2024, she undertook a volunteer research internship with Nichola Calvani hosted by The Education Abroad Network (TEAN). While in the lab, she assisted AVBS honours student Chelsie Uthayakumar in her ‘Beyond Suspicion’ Fasciola hepatica drug resistance project by conducting coprological ELISAs and faecal PCRs to validate traditional diagnostics (sedimentation and faecal egg count) pre- and post-drug treatment. During her time in the lab, she fell in love with the research side of science and enjoyed how animal welfare was still deeply intertwined with it. This led her to current status as a MPhil student researching Fasciola hepatica and investigating the drivers of their early development within the host.
Talk Title Growth and development of Fasciola hepatica on an in vitro 3D cell culture model: how does it compare to in vivo?
Authors Hayley Martinez DeCristi1, Michael Kuligowski2, Katharine Muscat1, Javier Gonzalez Miguel3, Nichola Eliza Davies Calvani1
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, NSW 2006, Australia
- Sydney Microscopy and Microanalysis, The University of Sydney, NSW 2006, Australia
- Laboratory of Helminth Parasites of Zoonotic Importance, Institute of Natural Resources and Agrobiology of Salamanca, Salamanca, Spain
Background and Aims
Fasciola hepatica is a globally distributed helminth of importance to both human and animal health. Critical information on how F. hepatica interacts with and defends against immune responses from its mammalian host is severely lacking due to a reliance on natural hosts (livestock) or laboratory models (rodents). The recent development of HepG2-derived 3D spheroid co-culture model supports growth and development of F. hepatica newly excysted juveniles (NEJ) under biologically relevant conditions without the need for an animal host. However, validation against in vivo infection is lacking. This study aimed to validate the HepG2 co-culture model against in vivo infection, using advanced microscopy methods.
Methods
In vivo samples from C57BL/6 mice, which were infected with 175 metacercariae each, and in vitro NEJ from the HepG2 co-culture model were collected at 12, 48, 120, 144, 168, 180, and 192 hours post infection. Objective comparison of the growth (length and width) and development of external morphological (spines, sensory papillae, suckers) and internal anatomical (musculature, gut and uterine development) features between the two culture conditions were made using fluorescent confocal and scanning electron microscopy.
Results
The data obtained provides the first detailed morphological comparison of the growth and development of F. hepatica NEJ cultured in vitro and in vivo and serves as a benchmark for the refinement and development of future in vitro co-culture models.
Conclusion
The use of animal-free models to generate in vivo-like parasites, validated herein through advanced imaging technologies, will enable unprecedented exploration of the intricacies of early infection, ultimately streamlining therapeutic discovery. Future work will incorporate spatial transcriptomic analysis to elucidate temporal shifts in F. hepatica development and the subsequent discovery of drug and vaccine targets.
During this Seminar Series we are also highlighting World Malaria Day which is an occasion to highlight the need for continued investment and sustained political commitment for malaria prevention and control. It was instituted by WHO Member States during the World Health Assembly of 2007.
