Saturday, September 29, 2012

Biological 'internet' lets cells communicate

The internet basically consists of a bunch of computers that are connected with each other globally. By sending messages back and forth, we gain access to web pages and are able to communicate with other people through the web. This principle also exists in the body: cells communicate with each other using a variety of molecules, such as hormones, chemokines, cytokines. Everything takes place in an endlessly complex network, far beyond our own attempts with the internet. Scientists from the Stanford University Medical Center have found a way to send artificial messages to cells in the body, by harnessing the power of viruses. This way, they have created something that may be regarded as the biological internet, or Bi-Fi, as they have named it themselves.

A virus called M13 was used for the experiments. This particular variant is a bacteriophage, which means it is specialized in infecting bacteria. It does not kill its hosts, however: instead it replicates its own genetic material, which is consequently packed and sent to other bacteria. Such mechanisms are pretty common for viruses, because they 'survive' by letting their host do all the work. The Stanford scientists harnessed their non-lethal characteristics and engineered a variant, able to send artificial messages.
An electron microscopy picture of a M13 virus. As can be observed, it is very long-stretched.
Our body has fantastic regulatory mechanisms in place to make sure that organs, tissues and cells continue to do their job. However, in some diseases, a new set of instructions are required to make sure that the things that went wrong are repaired. This may include upping the production of certain molecules or initiating repair mechanisms that otherwise stay dormant. Because the body has a set of predefined rules, it is sometimes necessary to change the instructions, which is where Stanford's Bi-Fi comes in handy.

The M13 system can be used for a variety of purposes: its advantage is that messages are not constrained to a certain network. Normally, cells are tasked with managing certain functions, and their communication with others is restrained to those that fit within their purpose in the body. However, the genetically engineered M13 can send all sorts of messages, depending on what the scientists want. Examples include telling cells to start growing, stop growing, come closer, swim away, produce insulin, or other messages that can be genetically encoded.

Using viruses to spread messages throughout the body and delivering it to specifically targeted cells is a pretty interesting idea. It could have a big impact on our abilities to modify the body, which is a very complex network of cells and chemical messages. An internet-like approach therefore seems suitable to overcome the chaos. Of course, a lot of work has to be done to expand its use, but the scientists have already shown to be capable of transmitting messages over a distance of 7cm, which, biologically speaking, is an impressive feat. Obviously, we do need a variant capable of infecting human cells if we want to make this work for curing disease.

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