The human immune system, that marvel of complexity, subtlety, and sophistication, includes a billion-year-old family of proteins used by bacteria to defend themselves against viruses, scientists at Dana-Farber Cancer Institute and in Israel have discovered.
The findings, published online today by the journal Science, are the latest in a growing body of evidence that components of our immune system — as advanced a shield against disease as exists on the planet — evolved early in ancient forms of life. The study shows that the immune system absorbed already existing elements and, over eons of evolution, put them to use in novel ways to meet the requirements of creatures as biologically complicated as human beings.
