How BK virus damages DNA

In laboratory studies using the human tissue that lines the urinary tract (urothelium), the team observed DNA damage patterns caused by the cell’s antiviral defenses after controlled exposure to BK virus—the childhood infection identified earlier as lying dormant in the kidney.

In this fight against the BK virus, “friendly fire” from enzymes meant to damage the virus can cause collateral damage in the cells’ own DNA. This evidence supports a theory in which an individual’s own antiviral response to BK virus infection causes the DNA mutations that can lead to cancer.