The study was published in The EMBO J and led by Peter Cockerill.
Cockerill and his team found that T lymphocytes are activated in response to an infection, the immune system leaves behind “imprints” in T lymphocytes’ chromosomes if it is the first time the body is experiencing a certain pathogen.
When the body encounters the pathogen a second time, these genes begin to be expressed again, following suit with reactivated immune cells. Immune cells remain in a dormant state in between infections when the body is healthy and functioning normally. However, these cells sleep with one eye open; they are more prepared than other non-primed immune cells to spring into action when the same pathogen returns for round two. The chromosome activation is what enables these dormant cells to “sit poised, ready to respond much faster when activated again in the future."
Keeping the “soldiers” prepared but at rest keeps the body from attacking its own cells by mistake. Autoimmune disease develops from an overactive or dysfunctional immune response, and with lymphocytes remaining dormant until needed, the risk of autoimmune disease is reduced.
Source: University of Birmingham