The ongoing quest to build life from scratch / by Karen Frances Eng

A synthetic biologist has created artificial cells that can “talk” to natural cells — but are they really alive?

How does one go about building a living cell from non-living components? And how will we know if we’ve succeeded — or even if we’re headed in the right direction? These are some of the questions that synthetic biologist Sheref Mansy, a TED Fellow, has been striving to answer at the Mansy Lab at the University of Trento in Italy. For the past six years,Mansy (TEDxUnTN Talk: Imitating cellular life) has been trying to make artificial cells that can interact with natural cells. His team recently achieved a notable success: their partially artificial cells can “hear” molecules naturally released from bacteria, and they can also synthesize and send molecules back in reply. Here, Mansy explains the science behind the breakthrough and discusses the potential implications.

Image: Jackie Ferrentino

Image: Jackie Ferrentino

The first challenge in trying to create a living cell is a doozy, since scientists haven’t settled on a universally agreed upon definition for life. “There are two common ways to view life: one is as a self-replicating system and the other is often referred to as autopoiesis, which essentially means the ability to persist over time,” says Mansy. “And the so-called NASA working definition of life says it is a self-sustained chemical system capable of Darwinian evolution, which sort of combines the two approaches.”

Mansy’s lab, however, has focused on building artificial cells that display another feature associated with life: communication. “All living things communicate in order to increase their chance of survival,” he says. “Communication is a good standard for evaluating ‘aliveness,’ because artificial cells can be subjected to a test that measures this ability.”

Could an artificial cell pass the cellular version of the Turing test? A Turing test is a way of evaluating the intelligence of a machine by assessing how well it communicates. “In the classical Turing test, you have a machine communicating with a person,” says Mansy. If the human thinks they are communicating with another human rather than a machine — in other words, if the machine’s responses are indistinguishable from a human’s — then the machine passes as intelligent.

All living things can communicate chemically with one another. “If we can build artificial cells that can sense the molecules naturally secreted from living cells and then synthesize a chemical message to go back to the natural cells, we can observe whether our artificials are lifelike enough to trick the natural cells into thinking that they are talking to a natural cell,” Mansy says. 

This is an excerpt. To read the full article, visit the TED Ideas blog >>>