Watch macrophages on guard against invaders

Macrophages are cells critical to the immune system – and new imaging reveals how they actively monitor their surroundings, searching for invaders.

The cells are highly specialised. They are the body’s frontline troops when it comes to detecting, combatting and destroying invading bacteria and other unwanted microbes. They also trigger another part of the system, known as T-cells, to release molecules known as cytokines which initiate inflammation at wound or infection sites.{%recommended 6832%}

Now, researchers at the University of Queensland’s Institute for Molecular Bioscience, in Australia, have used a form of imaging known as lattice light sheet microscopy (LLSM) to uncover for the first time the extraordinarily active surveillance carried out by the cells.

A team led by Adam Wall and Nicholas Condon found that the imaging revealed that the macrophages sported previously unknown structures that they dubbed “tent-pole ruffles”.

The ruffles continuously undulate, helping the immune cells to gulp in surrounding fluid for sampling – a process known as “macropinocytosis”.

“It’s really exciting to be able to see cell behaviour at unprecedented levels of resolution,” says Wall.

 “This is discovery science at the cutting edge of microscopy and reveals how much we still have to learn about how cells function.”

The research is published in the Journal of Cell Biology.