Shigella is an incredibly nasty bacteria related to E coli and Salmonella, and it's only found in apes — including us humans. When we get infected, it can cause lethal dysentery, so we've evolved a cunning way of fighting off the bug, a technique which has only just been observed. The human cells attack the invading Shigella using septin — a protein that's part of the cell's skeleton. The septin envelopes the bacteria; prevents it from spreading by limiting its access to actin, which it requires to move around; and marks it for destruction by autophagy, the cell's garbage disposal system.
This research is being presented at The American Society for Cell Biology 51st Annual Meeting this December, and it marks a novel discovery in the way our bodies fight off invaders. Throwing a cage around something and having it killed off is a pretty metal way to defend against disease!