Innate immune defenses triggered by unsuspected mechanism
To reach this conclusion, the researcher and his team inoculated a live strain of Mycobacterium tuberculosis to dendritic cells, which make up the innate immune system "In addition to observing thousands of DNA methylation changes very quickly after infection, there was a significant loss of methylation, which was strongly linked to the activation of neighbouring genes," said the principal investigator of the study.
Another surprising fact was that the reaction took place in the dendritic cells, whereas the latter did not multiply. "Normally demethylation occurs during cell division. The rapid triggering of this epigenetic change in cells that did not divide surprised us," said Alain Pacis, a doctoral student and first author of the study. "We must further explore the mechanism that makes this process possible."
Recent studies suggest that after first encountering a pathogen or other immune stimuli, innate immune cells keep the attack in memory to respond more effectively and more rapidly to future attacks, much like the adaptive immune system. According to Barreiro, the ability of these cells to remember past attacks can be explained by the lasting epigenetic changes that occur during the first infection. "Several clues lead us to believe that the innate immune system also has immunological memory, and the demethylation of DNA may play an important role in the acquisition of this memory. This is another avenue to verify."
Much remains to be done to explain the mysteries surrounding DNA methylation and the mechanisms by which it regulates the innate immune system and gives it a certain memory. Nevertheless, the discovery of the researchers sheds new light on how to approach the development of vaccines, in particular, by further considering the role of various epigenetic perturbations in triggering the immune response.
Original publication
Alain Pacis, Ludovic Tailleux, Alexander M Morin, John Lambourne, Julia L Maclsaac, Vania Yotova, Anne Dumaine, Anne Danckaert, Francesca Luca, Jean-Christophe Grenier, Kasper D Hansen, Brigitte Gicquel, Miao Yu, Athma Pai, Chuan He, Jenny Tung, Tomi Pastinen, Michael S Kobor, Roger Pique-Regi, Yoav Gilad, and Luis B Barreiro ; "Bacterial infection remodels the DNA methylation landscape of human dendritic cells"; Genome Res.; 2015
Most read news
Original publication
Alain Pacis, Ludovic Tailleux, Alexander M Morin, John Lambourne, Julia L Maclsaac, Vania Yotova, Anne Dumaine, Anne Danckaert, Francesca Luca, Jean-Christophe Grenier, Kasper D Hansen, Brigitte Gicquel, Miao Yu, Athma Pai, Chuan He, Jenny Tung, Tomi Pastinen, Michael S Kobor, Roger Pique-Regi, Yoav Gilad, and Luis B Barreiro ; "Bacterial infection remodels the DNA methylation landscape of human dendritic cells"; Genome Res.; 2015
Topics
Organizations
Other news from the department science
Get the life science industry in your inbox
From now on, don't miss a thing: Our newsletter for biotechnology, pharma and life sciences brings you up to date every Tuesday and Thursday. The latest industry news, product highlights and innovations - compact and easy to understand in your inbox. Researched by us so you don't have to.