One of biology’s great mysteries is the blood-brain barrier, which lines blood vessels in the brain. It normally keeps the brain healthy by preventing bacteria and large molecules in the bloodstream from reaching the central nervous system. A few fearsome agents, however—including meningitis pathogens and cancer cells—somehow make it across. Several research teams have recently announced fresh insights on how the invaders get through, findings that also suggest new ways to send drugs across the barrier to go after them.
Researchers in the U.S. and the U.K. investigated how three major meningitis-producing bacteria avoid being blocked by barrier cells in the brain. They discovered that all three lock onto a barrier-cell protein called the laminin receptor. From there the germs are sent on to another receptor and into the brain, where infection-fighting immune cells cannot reach them. In an effort to provide broad protection against meningitis, the researchers are now ...
