Increasingly fine control over our immune systems will be very important to the future of longevity. The immune system is vital not just to our resistance to pathogens, but also to destruction of cancerous cells and destruction of senescent cells, amongst other duties. Both cancerous and senescent cells greatly harm us in their different ways.
One thing that has become apparent from watching researchers working on the immune system is that our immune systems are capable of far more than they presently accomplish. If intelligently dialed up or dialed back, directed towards specific targets, rebooted when performing poorly, and so forth, we could benefit greatly. We all have a horde of defenders in our bodies, but their leadership just isn't as good as it might be, and becomes ever more confused with each new battle.
The more threats you have encountered, the more cells become devoted to memory; eventually you don't have enough naive T cells left to mount any sort of effective defense.
A human-assisted human immune system could overcome all of these obstacles, and we've seen the first steps down this road already. One positive sign is that even incremental progress in immune system control can bring great benefits, meaning that step-by-step commercialization will likely support development all the way to a very sophisticated merging of machinery and cells a few decades from now.
Here is an example of a positive incremental step I noticed recently:
Professor Jonathan Sprent and Dr Kylie Webster from Sydney's Garvan Institute of Medical Research, in collaboration with colleagues, Dr Shane Grey and Stacey Walters, have successfully tested a method, in experimental mice, of adjusting the immune system for just long enough to receive a tissue transplant and accept it as 'self'. At no stage, during or after the procedure, is there any need for immunosuppressive drugs.
We took normal, healthy mice, injected them for three consecutive days with the complex, then transplanted insulin-producing cells on the fourth day," said Kylie. "By the time of transplant there were huge numbers of T regulatory cells in their systems, making graft-destroying T cells ineffective."
"The numbers of T regulatory cells dropped over time, and the immune systems returned to normal in about two weeks. By that time 80% of the mice had accepted the grafts of insulin producing cells as their own."
"This acceptance rate is very high for transplantation, with mice normally rejecting grafts within 2-3 weeks."