How can you know if something’s changed, if you didn’t see what it looked like to start with? That was the idea behind a new study that profiled DNA methylation in the immune development of youngsters.
With more and more focus on environmental causes of immune diseases, and their epigenetic links, Australian researchers decided to figure out what DNA methylation changes were going on during “normal” development, so that they could work on ones that lead to immune problems later.
“Many researchers are now interested in the extent to which epigenetics may be responsible for the susceptibility to environment-driven immune disease. As a prelude to further studies in the area we wanted to determine the extent to which epigenetic changes in immune-related genes occur during normal immune development, and identify some key pathways, which may be candidates for epigenetic change.” Says lead author David Martino from the Murdoch Children’s Research Institute. “Our study was about assessing the extent to which DNA methylation varies during early immune development in mononuclear cells.”
“We collected blood samples from a small number of individuals at birth, 1year, 2.5years and 5years and phenotyped the mononuclear cell populations. We also collected DNA from these cells and performed genome-scale DNA methylation analysis. Using exploratory statistical approaches and pathways analysis we identified dynamic patterns of DNA methylation, which change during early immune development in normal individuals.” Explained Martino.
The Aussie team found that while global DNA methylation didn’t change much between birth and 5 years of age, the location of those marks did. Those changes were so consistent that the researchers could easily distinguish the 1 year olds profiles from 5 year olds, with the 2.5-year-old patterns looking like a mixture of the two.
Based on their observations, the authors think that this period of DNA methylation shifting in early life is especially susceptible to outside environmental influences, and they hope to use their new knowledge as a springboard towards understanding the epigenetic role in immune diseases.
Stay on top of the shifting DNAm patterns in Epigenetics, September 2011.