Instead of engineering cells to work as individuals, researchers are working on cellular machines that ‘talk’ to each other, and behave in sophisticated ways. Synthetic biology is going multicellular. There are an increasing number of demonstrations showing what’s possible with multiple cells.
The latest example comes from a team led by Matthew Bennett at Rice University in Houston, Texas. They developed a system that at its simplest encourages cooperation between two distinct populations of Escherichia coli. One produces an “activator” signalling molecule that triggers the bacteria in the second population to produce a “repressor”. This signal can travel the other way and turn off production of the activating molecule.
Multicellular synthetic biology could also become a big player in medicine. “The medium-term goal is working with systems like the gut microbiome, in which we can deploy cells to report about or alter their environment,” says Bennett. There has already been some success using engineered cells to patrol our guts. These cells might become even better at diagnosis and treatment if they begin to communicate with one another and with other microbes in the gut.
Cancer could be another target. “You might want your engineered cells to figure out whether they are sitting next to a tumour or not, and if so, release a drug,” says Leonard, who recently described a technology that will allow mammalian cells to interact with multicellular networks in their environment. “It’s clear that fully exploiting the unique capabilities of living cells will ultimately require us to go multicellular,”