IMMUNOLOGY2024™ Conference Recordings-Antimicrobial signaling at the maternal-fetal interface

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Video Summary

The speaker focused on the maternal-fetal interface, especially trophoblasts, which form the placenta’s primary defensive barrier. She explained the main human trophoblast types: cytotrophoblasts, extravillous trophoblasts, and the syncytiotrophoblast, a fused layer covering the placenta. A key theme was the placenta’s dual relationship with viruses: it depends on endogenous retroviral fusion proteins to form the syncytium, yet it must also block harmful vertical transmission.<br /><br />She described how human trophoblasts are unusually resistant to infection and constitutively release type III interferons, which create an antiviral state through interferon-stimulated genes. She also discussed a likely trigger for this response: the C19MC microRNA cluster and associated double-stranded RNA, which may act as a viral mimic.<br /><br />A major technical advance in the lab was the development of placental organoids from full-term tissue. These organoids can be expanded, cryopreserved, genetically edited, and differentiated into multiple trophoblast lineages. They also help overcome limitations of single-cell sequencing, especially for studying syncytiotrophoblasts, where single-nucleus RNA-seq is more informative.<br /><br />Finally, she highlighted comparative placenta biology across species, including macaques, lemurs, pigs, ruminants, and mice, to understand how interferon-based defense evolved.

Keywords

maternal-fetal interface

trophoblasts

syncytiotrophoblast

placenta

type III interferons

placental organoids

vertical transmission