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Updated: Jun 22, 2026
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Ex vivo Culture of Human Placental Explants for the Study of Viral Transmission Across the Maternal-Fetal Interface
Published on: December 30, 2025
Review: human endogenous retroviruses and the placenta
1Department of Obstetrics, Gynecology and Women's Health, Division of Reproductive Endocrinology and Infertility, University of Missouri-Columbia, Columbia, Missouri 65201, USA. sugimotoj@health.missouri.edu
Reproductive Sciences (Thousand Oaks, Calif.)
|May 29, 2009
Summary
Human endogenous retroviruses (HERVs), remnants of ancient infections, constitute a significant portion of the human genome. This review explores their crucial roles in placental function and dysfunction.
Area of Science:
- Genomics and Molecular Biology
- Reproductive Biology
- Virology
Background:
- Up to 8% of the human genome comprises sequences of retroviral origin, known as human endogenous retroviruses (HERVs).
- These HERVs originated from infections over 25 million years ago and have coevolved with the human host.
- While most HERV sequences are silenced, some remain functional, influencing human health and organ function.
Purpose of the Study:
- To review the contribution of retroelements, particularly HERVs, to human placental function and dysfunction.
- To explore the unique expression of retroviral sequences in the human placenta compared to other tissues.
- To emphasize the role of epigenetic regulation in controlling retroelement expression.
Main Methods:
- Literature review focusing on retroelements, HERVs, and placental biology.
- Analysis of existing data on HERV expression patterns in placental tissues.
- Discussion of mechanisms including fusogenic and immunosuppressive HERV activities and epigenetic regulation.
Main Results:
- HERVs are actively expressed in the human placenta, a unique characteristic among human tissues.
- HERV-derived products can be linked to human diseases and are essential for certain organ functions.
- Specific HERV activities, such as fusogenic and immunosuppressive functions, are relevant to placental biology.
Conclusions:
- The human placenta is a key site for understanding the functional significance of HERVs.
- HERVs play a critical role in both normal placental function and pathological conditions.
- Epigenetic mechanisms are crucial for regulating HERV expression and their impact on the placenta.
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