Tunnelling nanotubes seem to play a major role in anything from how our immune system responds to attacks, to how damaged muscle is repaired after a heart attack (Image: Paul McMenamin / UWA)

HAD Amin Rustom not messed up, he would not have stumbled upon one of the biggest discoveries in biology of recent times. It all began in 2000, when he saw something strange under his microscope. A very long, thin tube had formed between two of the rat cells that he was studying. It looked like nothing he had ever seen before.

His supervisor, Hans-Hermann Gerdes, asked him to repeat the experiment. Rustom did, and saw nothing unusual. When Gerdes grilled him, Rustom admitted that the first time around he had not followed the standard protocol of swapping the liquid in which the cells were growing between observations. Gerdes made him redo the experiment, mistakes and all, and there they were again: long, delicate connections between cells. This was something new – a previously unknown way in which animal cells can communicate with each other.

Gerdes and Rustom, then at Heidelberg University in Germany, called the connections tunnelling nanotubes. Aware that they might be onto something significant, the duo slogged away to produce convincing evidence and eventually published a landmark paper in 2004 (Science, vol 303, p 1007).

A mere curiosity?

At the time, it was not clear whether these structures were anything more than a curiosity seen only in peculiar circumstances. Since their pioneering paper appeared, however, other groups have started finding nanotubes in all sorts of places, from nerve cells to heart cells. And far from …