Advances in cancer immunotherapy may help autoimmune therapies defend themselves.
Is human immunology basically too crazy complex for the human mind? Evidence to date suggests yes, at least for my mind.
In almost every story I write about cancer immunology or autoimmune disease, I learn about previously unknown (to me) functions within the three-ring circus of immune cells. Or I find out about yet more types of these cells, like double-negative T cells, which can defend against graft disease and maybe type 1 diabetes. Who knew?
Well, yeah, thousands of immunologists.
All of us who follow cancer research, though, do know a (simplified) version of one genuine breakthrough in immunology, checkpoint blockade inhibitors, which garnered Nobel Prizes last October.
These drugs take on one of deepest questions in cancer biology: why the immune system doesn’t snuff out cancer cells, which by definition are genetically abnormal, often wildly abnormal.
Checkpoint blockades can hold off the T cells on patrol for just such outsiders. It turns out that a protein on the surface of tumor cells called PD-L1 can grab onto a surface protein on the T cell called PD-1 and so disarm the T cell. (Nothing to look at here, officer! Ignore my multiple heads and antitank guns!)
Other headlines in cancer immunotherapy come from chimeric antigen receptor T (CAR-T) cell drugs, treating patients with certain blood cancers in which B cells go bad. The two such drugs with FDA approval work by taking T cells from the patients, reengineering the T cells to attack those cancerous B cells, and reinserting the T cells.
This method is often effective when nothing else works, but is always worryingly slow and extremely costly.
So there’s plenty of work in labs, and a few clinics, to take a logical but intimidating next step: Engineering off-the shelf T cells to do the job, hiding them from each patient’s immune system with tricks learned from checkpoint blockade research and similar immunology findings.
Still with me?
Okay, if those cell-shielding techniques eventually work, can a similar attack be made in autoimmune diseases such as type 1 diabetes?
In type 1 diabetes, effective ways to stop the autoimmune attacks from trigger-happy T cells exist only in lab mice. And that’s a problem not just in slowing or stopping disease progression but in trying to treat it. The most promising current approach is to encapsulate insulin-producing beta cells. This has been pursued for many decades, with many barriers. Perhaps the highest (if least surprising) barrier is that the capsules always get clogged up by the immune system.
The latest capsule approaches, starting with beta cells made by reprogramming cells, try sophisticated material-science strategies to blunt this attack and may do much better.
But as long as we’re already playing genetic games with those engineered beta cells, why not also try the same immune-evading tricks being studied in CAR-T experiments?
That’s the basic idea behind efforts by Altheascience, a Viacyte/CRISPR Therapeutics collaboration, and others. Which just maybe will produce capsules that, replaced every year or so as necessary, are working cures for type 1 diabetes. Which we would all fully understand.