Multilineage modelling of early placental responses to pathogens at single-cell resolution

The placenta is a unique organ that plays a critical role during foetal development, serving as an extraordinary protective barrier against infections. Despite this, pathogens such as the eukaryotic parasites Plasmodium falciparum and Toxoplasma gondii, and the bacterium Listeria monocytogenes, can lead to pregnancy complications, causing miscarriage, low birth weight, stillbirth, and developmental anomalies. In this thesis, I model placental infections using in vitro and ex vivo placental models such as human trophoblast stem cells (hTSCs), organoids, and placental explants, and perform a comprehensive single-cell transcriptomic analysis of their responses. Firstly, I outline the physiological structure and role of the placenta in supporting and protecting the developing foetus. I introduce biological models for studying placental infections and describe single-cell transcriptomics and their potential to study host-pathogen interactions. Secondly, I establish various placental models. I utilise hTSCs to differentiate into extravillous trophoblasts (EVT) and derive organoids from hTSCs and primary tissue with a reversed polarity that can mimic the natural spatial organisation of the placental villus. Additionally, I set up an improved placental explant system that preserves all the placental cell lineages. Thirdly, I define the conditions to infect placental in vitro models with Listeria monocytogenes, Plasmodium falciparum, and Toxoplasma gondii. Using single-cell transcriptomics, I benchmark the infection responses of each system to determine the optimal approach for modelling infections in the lab. Fourthly, I profile early placental responses to infections using multilineage placental explants. I uncover the placental defence mechanisms to combat infections and the pathways exploited by pathogens for their progression, utilising single-cell transcriptomics, immunoassays, and microscopy. Finally, I discuss the frontiers in modelling infections in the human placenta, highlight the potential of single-cell genomics to improve our understanding of host-pathogen interactions, and share my perspectives on future treatments for vertically transmitted infection.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2024

Author dc:creator

• Ruiz Morales, Elias Rafael

Advisor dc:contributor.advisor

• Vento-Tormo, Roser

• Genomics
• Host-pathogen interactions
• Immunology
• Infections
• Listeria monocytogenes
• Placenta
• Plasmodium falciparum
• Single-cell
• Toxoplasma gondii

Licence

• https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/981cf9a4-076e-45db-8ec6-548a1699b2bf/download
• http://purl.org/NET/rdflicense/allrightsreserved

Language dc:language

eng

Author Identifier

0000-0002-5801-6190

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/379789