Researchers from the Wellcome Sanger Institute, Newcastle University and Ghent University, Belgium, mapped thymus tissue through the human lifespan to understand how it develops and makes vital immune cells called T cells.

Professor Tom Taghon, a senior author of the study from Ghent University, Belgium, said: "We now have a very detailed understanding of how T cells form in healthy tissue. We have been able to identify a similar population of precursor cells in the developing thymus and liver, and we believe that these precursors are important for initiating T cell development in the fetus, and for the establishment of a fully competent thymus organ. This is helping us put jigsaw pieces together to get a bigger picture of how immunity develops."

The thymus is unusual in that it is largest and most active in childhood and shrinks after puberty. The thymus has been called the 'pacemaker of life' and by age 35 has almost disappeared. Understanding how the thymus develops and then withers could cast light on aging and how the immune system changes through life.

https://www.sciencedaily.com/releases/2020/02/200220141708.htm