The human fetal immune system begins to develop early during gestation, however, factors responsible for fetal immune-priming remain elusive. Using multiple complementary approaches, Dr. Florent Ginhoux from A*STAR's Singapore Immunology Network (SIgN), Professor Jerry Chan from KK Women's and Children's Hospital (KKH), Professor Salvatore Albani from the SingHealth Duke-NUS Translational Immunology Institute, and collaborators from Cambridge University explored potential exposure to microbial agents in-utero. The team identified live microbes across fetal organs that stimulate the activation of fetal T-cells during the second trimester of gestation. Their study published in the scientific journal, Cell, on 24 June 2021.