Scientists turn human cells into living computers

Researchers Keren Roas and Lior Nissim of the Hebrew University of Jerusalem have become the first to create artificial genetic systems inside human cells that are capable of processing complex information and following precise instructions. Although experts have long wanted to program cells to recognize and respond to disease conditions, the main obstacle has been the lack of suitable genetic building blocks.

Previous attempts have worked in a stepwise fashion, meaning that each new command required an additional layer of computational operations within the cell. The larger the system, the faster the reliability and efficiency of these biological calculations declined. The Jerusalem team, however, has taken a completely new route that allows cells to execute complex programs using a significantly smaller number of steps and genetic material. In doing so, they have maintained the full functionality of the cell without overloading it.

To achieve this, they used a natural process called RNA trans-splicing, in which parts of genetic messages are joined together inside a cell. They combined this with their own artificially designed regulatory elements. They created special molecular tools that act as biological processors, triggering the expression of specific genes according to a predetermined plan. Because the system can process multiple signals at once, it is extremely efficient.

As part of the demonstration, scientists built biological devices that mimic real computer components. They created a biological full adder that can perform simple binary math, similar to a 3-bit unit in a computer processor. They also developed a biological version of a multiplexer, an electronic component that selects from multiple signals and passes them on. All of these processes were monitored using fluorescent proteins that glow in different colors.

Despite the initial excitement, transferring such laboratory systems into living human bodies carries unpredictable risks. That's why researchers have already built in a safety mechanism. If a cell detects an invalid or overloaded configuration, it triggers a special warning. This could prevent fatal errors in medical interventions in the future.

In the future, these smart cells could continuously monitor the body's environment. A programmed cell could check for multiple disease markers at once and release a drug only when it detects a specific combination. To demonstrate this concept, the cells were programmed to secrete interleukin-15 (IL-15), a protein that stimulates the immune system to fight cancer.