Watch a predatory immune cell capture and engulf its prey
Macrophages push and pull on particularly stubborn particles to grapple them into position.
Researchers manipulating a microrobot have zeroed in on how predatory immune cells nab their prey.
Massachusetts Institute of Technology's Simone Schuerle and colleagues explored the way immune cells that engulf invading organisms called macrophages grab hold of and drag their quarry towards them.
Immune cells such as macrophages sense biochemical cues in their environment to track down invaders and eventually engulf and neutralise them.
But their finely evolved system of adhesion and bonding, used to hold onto their prey, has not been well-studied.
Using microrobots instead of real microbes, the team's technique – which let them control how hard it was for a macrophage to get a grip on a target – showed the cells align with yielding prey to more easily drag it in.
For more resistant prey, the cells employed a push-and-pull grappling method.
Macrophages aren't perfect, though. As resistance was increased, there also came a point when the microrobots escaped the macrophage's grip altogether.
The work was published in Science Robotics.