A team of scientists from the University of Edinburgh (UK) has achieved a milestone in regenerative medicine after completely restoring an organ in a living animal; specifically the thymus , the first organ in the body to deteriorate with aging . The results of the work have been published in the journal Development .
The thymus is a glandular structure that functions as part of the immune system and is located in the front part of the heart. Its job is to create T lymphocytes, a type of immune cell that is essential for fighting infection . Their reduction in size is one of the main reasons why the immune system becomes less effective and why we lose the ability to fight new infections, such as the flu, as we age.
To achieve this regeneration, the researchers genetically modified mice so that they could increase the levels of a protein called FOXN1 . This protein helps control how genes are turned on in the thymus. Thus, using chemical signals to stimulate the increase in FOXN1 in the mice, the scientists were able to induce immature cells in the thymus to activate. Once activated, the immature cells rebuilt the organ in the older mice .
Although scientists had tried to regenerate this organ of the immune system before, using sex hormones, this technique only managed to temporarily regenerate the organ and also with limited functionality. What is innovative about this technique, apart from achieving full functionality, is that the regenerated thymus was also much larger than the organs in old mice not treated with this new technique.
“Our results suggest that if we follow the same path in humans we can improve thymus function and therefore increase immunity in older patients, or those in whom the immune system has been suppressed, ” says Clare Blackburn, leader of the study.
