Fully Functional Thymus Grown In Mouse

Growing organs for human transplant is still a long way off, but this study is still a step forward

George Steinmetz/Corbis

In a new study published yesterday in Nature Cell Biology, scientists announced that they had managed to grow a fully functional thymus in a mouse. 

The thymus started out as part of a mouse embryo—a fibroblast, which researchers manipulated in the lab to form thymus cells. When those cells were placed in a mouse, they were able to form a fully functional thymus gland. 

The thymus, though not as well known an organ as the heart or liver, is pretty important. It helps produce white blood cells called T-cells. Without a working thymus, people can suffer compromised immune systems. As the BBC reports, researchers hope that eventually they might be able to use this kind of technique to replace the thymus of people born without one. A newly grown thymus could also boost the immune system of bone marrow patients or the elderly. 

Actually moving from an experiment with mice to treating people is a huge jump, though. The Guardian spoke with Chris Mason, an expert not involved with the study who said that: 

"The time and resources required to turn this mouse proof-of-concept study into a safe and effective routine therapy for patients will be very significant – 10 years and tens of millions of pounds at a bare minimum.

This isn't the only recent news of functional organs thriving where they're not supposed to be. Last week, a different group of researchers announced that they had managed to keep genetically modified pig hearts alive in the stomachs of baboons after transplantation. 

These studies, along with countless others, are focused on advancing the science around organ transplants. According to the Mayo Clinic, over 100,000 people in the United States are waiting for an organ. Many will receive one, but only after a wait. An estimated 18 people die every day while waiting for an organ. And that’s just in the United States. Worldwide, the need is even greater, leaving some people willing to turn to the black market to obtain organs like kidneys.