SCIENTISTS BUILD WORKING HUMAN THYMUS

Using human stem cells, researchers at the Francis Crick Institute and University College London have, for the first time, grown a working human thymus.
The thymus, sitting between the heart and the sternum, is essential in establishing the body’s immune system. Once that task is done, the thymus gradually wastes away until it virtually disappears in elderly persons.
A child with a damaged thymus or born without one faces a death sentence from infection.
Now the Crick-London research team has opened a means of escape from that fate.
To build the thymus, the scientists collected thymuses from patients undergoing heart surgery, then cultured hordes of cells from the harvested glands. To give the cells a place to multiply, the team developed a surgical technique that enabled them to remove cells from a rat thymus, leaving only the structural framework.
The researchers then populated the framework with about six million cells from the cultured crop, which began to organize themselves.
After five days, the rat-size thymus resembled the thymus in a nine-week-old human fetus; when it finished growing, the thymus glands that grew in rats were producing key biochemical components of the immune system.
The Crick-London group is now working to scale up the technique to create a full-size human thymus.
TRENDPOST: A lab-grown thymus could do more than save the lives of children and young adults with missing or damaged thymus glands, the researchers say.
The cultured glands also could be used in transplants: by growing and implanting a new thymus in an adult transplant patient, the person’s body might accept the replacement organ, eliminating the need for a long regimen of immune-suppressing drugs.