Early human embryonic cells may be vulnerable to SARS-CoV-2 infection – Image for illustrative purposes only (Image credits: Unsplash)
Riverside, California — Researchers at the University of California, Riverside have uncovered evidence that cells forming the earliest layers of human embryos may face significant vulnerability to SARS-CoV-2, the virus behind COVID-19. Their work, published this week, highlights how these nascent tissues interact with virus-like particles in lab models, shedding light on potential risks during the critical first weeks of pregnancy.[1][2] This discovery arrives amid ongoing questions about long-term effects from maternal infections, urging closer scrutiny of developmental outcomes.
A Lab Model Unlocks Early Development Secrets
Scientists turned to a “disease-in-a-dish” approach to probe stages of human growth that remain elusive in live pregnancies. Ann Song, a doctoral student in molecular, cell, and systems biology, and her advisor Prue Talbot differentiated human embryonic stem cells into key early cell types, including those mimicking the ectoderm, mesoderm, and endoderm.[1] They then exposed these models to SARS-CoV-2 pseudoparticles, harmless mimics that glow upon cell entry to reveal infection patterns.
This method allowed precise measurement of susceptibility without ethical concerns tied to actual embryos. Multiple cell types took up the particles, confirming broad potential access for the virus. Yet variation emerged clearly, with some layers proving far more receptive than others. The technique built on prior stem cell research but marked a novel focus on post-implantation stages, roughly weeks one through four.
Ectoderm Stands Out in Infection Trials
Ectodermal cells, precursors to the skin and nervous system, displayed exceptional vulnerability. Song reported that these cells proved about 23 times more susceptible than undifferentiated embryonic stem cells and six times more so than mesodermal cells, which form muscles and organs.[1] Such disparity underscored a targeted tropism, where the virus favored outer-layer progenitors…