Accumulated bits of a cell's own DNA can trigger autoimmune disease

A security system wired within every cell to detect the presence of rogue viral DNA can sometimes go awry, triggering an autoimmune response to single-stranded bits of the cell's own DNA, according to a report in the August 22nd issue of the journal Cell, a Cell Press publication. The source of that single-stranded DNA is so-called endogenous retroelements—genetic elements accounting for a substantial portion of the genome that can move to new locations using a "copy and paste" mechanism, according to the researchers.

The new findings help to explain the cause of a rare autoimmune disorder known as Aicardi-Goutieres Syndrome in which infants appear to suffer from an acute viral infection, despite the fact that no virus had ever been found.