An interesting new study has demonstrated a method to reprogram specific T cells. Much like researchers have been experimenting recently with macrophages and making them change into an anti-inflammatory rather than a proinflammatory type, the team here has achieved similar results with T cells.
As we age, the immune system becomes dysfunctional, either due to immune cells becoming overactive and creating too much inflammation, or to cells that suppress the immune system, such as senescent cells that inhibit cell function.
A dysfunctional immune system leaves us vulnerable to diseases, and chronic levels of inflammation from excessive immune responses prevent tissue regeneration and wound healing. The researchers here have discovered how to target pro-inflammatory T cells that increase the immune response and inflammation and change them into anti-inflammatory cells that suppress the immune response, and vice versa.
Transforming T cells
The team studied two specialized types of T cells during the experiment: effector T cells, which activate the immune system in the presence of pathogens, and regulatory T cells, which keep the immune system in check and stop it from attacking healthy cells in the body. Autoimmune diseases are caused when the immune system fails to be kept in check and it mounts an immune response against its own host cells and damages tissues and organs.
The team identified a small-molecule drug that was able to reprogram effector T cells and make them transform into regulatory T cells. This approach has a number of important medical applications. For example, it could be used to treat autoimmune disease by reducing the over-activation of effector T cells and helping to restore the balance of the immune system by tackling the disease at the root cause.
This approach also has potential applications in stem cell therapies: increasing regulatory T cells may help to promote immune tolerance and prevent the rejection of transplanted stem cells. This is consistent with other approaches where the immune response has been reduced along with inflammation by changing macrophages to favour a healing type over a proinflammatory type and helping improve transplanted stem cell survival.
Finally, it may also find utility in treating cancer by helping the immune system identify cancer cells and attacking them. Many cancers take control of regulatory T cells and use them to suppress the immune system, allowing tumors to grow without being detected and attacked. This technique could potentially be used to switch regulatory T cells making them into effector T cells and boosting the immune system and its response, so it can better detect and eliminate cancer cells. Once the therapy is finished, the T cells could be encouraged to swap back to regulatory T cells to calm the boosted immune system down again.
As a number of our recent articles have discussed, the manipulation of the immune system is rapidly becoming a hot topic in research and an area of increasingly intense activity.
Improving the body’s own defence system and regulating its activity opens the door to treating many diseases, including those associated with aging. Turning up the immune response to fight cancer and turn it down to facilitate healing and stem cell transplants is an exciting possibility, and the level of control we have over the immune system is improving rapidly.