Celebrate National Science Week 2026! Join our online ASP Seminar Series Friday 21 August @1pm AEST, featuring Lena Chng, PhD Student, Tonkin Laboratory, Infectious Diseases and Immune Defence Division, Walter and Eliza Hall Institute presenting “Identification and Characterisation of Cryptosporidium Effector Proteins in Host-Pathogen Interaction” and Jill Chmielewski, Walter and Eliza Hall Institute of Medical Research presenting her research with co-chairs Ben Liffner, Adelaide University and Grace Peters, University of New South Wales.
Please register online using this link for your unique passcode to join the seminar. After registering, you will receive a confirmation email containing information about joining the meeting.
Lena was born and raised in Singapore, completed her BSc at University of Queensland before moving on to a Genomics lab in Singapore conducting surveillance of zoonotic pathogens – where she worked with bats and small rodents. Lena was interested in doing a PhD and returning to Australia, hence found her way to Chris Tonkin’s lab which focuses on host-pathogen interaction in apicomplexans.
Talk Title: Identification and Characterisation of Cryptosporidium Effector Proteins in Host-Pathogen Interaction
Ch’ng, L.1,2*, Seizova, S.1,2, Marasigan, J. 1,2, Wiradiputri, K.1,2, Abdalla, W.1,2, Alammar A. 1,2, Uboldi, A. 1,2, Hesping, E. 1,2, Boddey, J. 1,2, Tonkin, C. 1,2
1 Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia; 2 Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia; *Presenting Author: chng.l@wehi.edu.au
The apicomplexan parasite Cryptosporidium causes the severe diarrheal disease, cryptosporidiosis, a leading cause of childhood mortality globally. Chronic diarrhoea leads to malnutrition and wasting in children under five, affecting physical and cognitive development1. The lack of diagnostic tools, effective treatment and vaccines for cryptosporidiosis exacerbates the global impact of this neglected pathogen on vulnerable populations. Cryptosporidium infects host enterocytes and like its cousins, Plasmodium and Toxoplasma, secretes proteins into its host cell to establish infection2. Remodelling of the host actin cytoskeleton is a key process that occurs during Cryptosporidum infection. Host filamentus actin accumulates at the host-pathogen interface, leading to the formation of an “actin-pedestal” which is vital for infection3. Another hallmark of Cyrptosporidium infection in the enterocytes include actin-dependent elongated microvilli, a morphological feature shared between enteric pathogens4.
Recently, a highly disordered exported effector, MVP1, was identified to facilitate microvilli elongation through the activation of actin polymerisation pathways5. Despite new findings, mechanistic involvement of secreted effectors in parasite invasion remains poorly understood.
In this study, we used TurboID and APEX- expressing host cell lines to identify effector proteins of Cryptosporidium. Using newly developed CRISPR-Cas12 technology and mouse models, we have generated transgenic HA-tagged parasites and show that two of these effectors are exported into the host upon invasion, localising with host actin. Using Yeast Two-hybrid screening, we identify binding partners for one of the effectors, providing evidence as to how they manipulate the host actin network. This study greatly expands our molecular understanding of host manipulation in Cryptosporidium infection, and highlights a new therapeutic pathway for the development of an efficacious anti-cryptosporidial agent.
Jill Chmielewski, Walter and Eliza Hall Institute of Medical Research, where she is a member of the Tham Lab.
Our ASP Online Seminar Series image is created by Thorey Jonsdottir.
