There is also a paper from some months back that is open access, and thus provides much more information for those who like to get at the source. This covers earlier work in which they manipulate cell signaling to regrow an existing thymus in situ and restore it to youthful activity:
This is good news for work on immune system rejuvenation, some of which is very focused on restoring the thymus to youthful activity. Immunosenescence is an important contribution to the frailty of aging. One of the issues with an aged immune system is that for various reasons it runs out of competent immune cells to tackle new threats. Means of restoring that population of cells include (a) a more active thymus, (b) clearing out dead wood memory T cells that are hanging around being useless, as that will spur the creation of naive T cell replacements, and (c) plain old cell therapies along the lines of culturing vast numbers of immune cells and infusing them on a regular basis.
A lot of this is very close to practical in the technology demonstration sense today, but of course regulation is the big roadblock in most of the world. It'll take a decade to get this through the very hostile-to-anything-new regulatory system, and of course treatments will only be ever be approved for very sick and damaged people. The existing regulatory system will never approve a thymus rejuvenation procedure for someone who is "only" old and immunosenescent, because that is not defined as a disease - that is a healthy person who is merely old, and shouldn't be treated at all in the eyes of the regulator. That must change, but the pressure for that will largely come from medical tourism if the course of recent history vis a vis first generation stem cell treatments is anything to go by.
Some years ago, transplantation of a thymus was shown to have benefits in mice along these lines, restoring a supply of immune cells, and that was good enough to attract more interest. Regrowing the existing atrophied thymus or putting a new one in place has thus been on the agenda for a while, e.g. in an ongoing SENS Research Foundation / Wake Forest Institute for Regenerative Medicine collaboration. That is a more traditional tissue engineering approach, with nanoscale scaffolds, a lot of work on cell differentiation strategies, and so forth. The ability to rejuvenate or regrow the thymus entirely from just a small population of cells, or a few altered protein levels, has come out of left field as something of a pleasant surprise.
http://dev.biologists.org/content/141/8/1627.full
This is good news for work on immune system rejuvenation, some of which is very focused on restoring the thymus to youthful activity. Immunosenescence is an important contribution to the frailty of aging. One of the issues with an aged immune system is that for various reasons it runs out of competent immune cells to tackle new threats. Means of restoring that population of cells include (a) a more active thymus, (b) clearing out dead wood memory T cells that are hanging around being useless, as that will spur the creation of naive T cell replacements, and (c) plain old cell therapies along the lines of culturing vast numbers of immune cells and infusing them on a regular basis.
A lot of this is very close to practical in the technology demonstration sense today, but of course regulation is the big roadblock in most of the world. It'll take a decade to get this through the very hostile-to-anything-new regulatory system, and of course treatments will only be ever be approved for very sick and damaged people. The existing regulatory system will never approve a thymus rejuvenation procedure for someone who is "only" old and immunosenescent, because that is not defined as a disease - that is a healthy person who is merely old, and shouldn't be treated at all in the eyes of the regulator. That must change, but the pressure for that will largely come from medical tourism if the course of recent history vis a vis first generation stem cell treatments is anything to go by.
Some years ago, transplantation of a thymus was shown to have benefits in mice along these lines, restoring a supply of immune cells, and that was good enough to attract more interest. Regrowing the existing atrophied thymus or putting a new one in place has thus been on the agenda for a while, e.g. in an ongoing SENS Research Foundation / Wake Forest Institute for Regenerative Medicine collaboration. That is a more traditional tissue engineering approach, with nanoscale scaffolds, a lot of work on cell differentiation strategies, and so forth. The ability to rejuvenate or regrow the thymus entirely from just a small population of cells, or a few altered protein levels, has come out of left field as something of a pleasant surprise.