The Sept. 17, 2012 news item on Nanowerk lays out the standard telephoning process, then applies it to mammalian cells (Note: I have removed a link),
Telephoning is a mutual exchange of information: A phones B and they both agree what B should do. Once this is done, Party B phones Party A to let him or her know. A no longer phones B. During this two-way communication, electrical signals are sent, and for their transmission suitable devices are necessary.
Based on this formula, a team of bioengineers headed by Martin Fussenegger and Jörg Stelling at ETH Zurich’s Department of Biosystems Science and Engineering in Basel has programmed mammalian cells in such a way that two cells can communicate via chemical signals (“Synthetic two-way communication between mammalian cells”).
Peter Ruegg’s Sept. 17, 2012 ETH Life article, (ETH is a science and technology university; in German: Eidgenössische Technische Hochschule Zürich) which originated the news item, outlines the research,
The researchers used suitable signal molecules and constructed “devices” out of biological components that receive, process and respond accordingly to the signals. The devices consist of suitable genes and their products, proteins, which are linked to each other logically.
An enzyme produces the amino acid L-tryptophan from indole, which has been introduced into the sender cell from outside. This little molecule enters the receiver cell, which processes the signal. The response to L-tryptophan is that the receiver produces acetaldehyde, which the sender cell can receive. If, after a certain time, a particular concentration of acetaldehyde has been attained or the indole is depleted, the sender cell stops producing L-tryptophan and the system switches itself off again.
Here are the specifics (from the Ruegg article),
For their experiment, the Basel-based researchers used so-called HEK cells – human kidney cells, in other words, which are often used in research. Moreover, the biological components necessary to construct the signal network can be used in a modular way. With these modules, the researchers were also able to connect other signal paths, including a signal cascade leading from the sender cell, through the information processing cell to the performing receiver cell without any feedback.
Thanks to their “cell phone”, the ETH-Zurich biotechnologists were able to simulate the latter accurately in a cell culture. They placed the sender and receiver module in the culture dish along with a population of endothelial cells, which line the blood-vessel walls. In response to the tryptophan signal, the receiver module formed the messenger VEGF [vascular endothelial growth factor, a signal protein] as well as acetaldehyde. This increases the permeability of the endothelial cells, which is a key prerequisite for blood-vessel growth.
Due to the acetaldehyde response, the sender module ultimately produced the signal molecule Ang1, which stops the permeability of the endothelial cells to inhibit blood-vessel growth.
At least one future application for this research is medical (from the Ruegg article),
This signal system is also found in the human body. If VEGF spirals out of control, however, too many blood vessels form, which ultimately feeds a growing tumour. The “cell phone” could therefore be a plausible strategy to halt the pathological formation of new blood vessels. “Communication is extremely important in controlling blood vessels,” says Fussenegger, “and we hope to be able to use synthetic ‘cell phones’ to correct or even cure disease-related cell communication systems precisely in the future with a ‘therapeutic call’.”
The scientists have found a way to illustrate their ‘cell phone’ research,
I have written for telecommunications companies and I think it’s safe to include my colleagues when I say that neither I nor any of them imagined the possibility of making therapeutic calls to our cells.