Innate immune defenses triggered by unsuspected mechanism

To the amazement of researchers in immunology and genetics, a previously unsuspected mechanism is activated in the presence of pathogens after only a few hours. "In the hours following an attack by bacteria, we observed the activation of thousand of genes in the cells of the innate immune system (the one we are born with) and the triggering of its immune defences," said Luis Barreiro, a researcher at the Sainte-Justine University Hospital Center (CHU Saint-Justine) and professor at the University of Montreal. "We were surprised that the bacterial infection caused thousands of changes in DNA methylation, while this epigenetic imprint was thought to be stable and non-reactive to environmental perturbations," he added.