The Coolest Medical Advance During My Career
So today I’m going to talk about something that is way cool. I think it is one of the most amazing developments in medicine since I finished my training. Now, it’s a little esoteric. I don’t know that it’s going to be directly relevant to your health, but I’ll bet you saw headlines about it from a week and a half or a couple of weeks ago. If you’ve read a little bit into the story, you might have thought, I don’t really understand this. This is too weird. With this talk, I’m going to present to you this topic of CAR T cells, which is just tremendously fascinating, and make the science of it understandable so you can look at it and share in my fascination. That’s really what this video is all about: just showing off cool stuff in medicine.
This new cancer therapy was approved by the FDA a couple of weeks ago, middle of August. The therapy is called CAR T. It has been described as a living drug which is a very apt description of it. The abbreviation stands for a chimeric antigen receptor (CAR) T cell. Let’s start with the first one: chimeric. Do you remember when you studied Greek mythology in high school what the chimera was? This was one of those mythological Greek animals that was several animals rolled into one. The chimera was the head of a lion, the head of a goat coming out of the back of the lion, and a snake for a tail. That’s a little weird.
Now, just as a side note, I’ve got to say, really? I mean, a lion head and a goat head and a snake tail like the Pegasus: super cool. The centaur, that’s pretty interesting. But this one, it’s kind of like Homer and Aristophanes are sitting around at the end of the day like, I’m out of ideas. You got anything? We’ve got to come up with another animal. Oh, wait! How about a lion and a goat and a snake and we roll them all up together? Anyway, that’s the chimera, a combination of different animals into one. That’s what helps us approach this whole new therapy of CAR T therapy. It is the combination of two very different, totally separate immune system functions into one therapy.
The first is the T cell of the name CAR T. The T cell is one of the subtypes of white blood cells. T cells are coordinators of immune system attack, and they can also be an attack cell themselves. So that’s the T cell; it’s an attack cell.
The other function is antibodies. For example, when you get your flu shot and a couple weeks later you have antibodies. Antibodies are proteins that are very specific in what they attach to. Each antibody has its own very precise specificity; it’s kind of like a key for a lock. You know, if you try to get into your house but you don’t use the right key, you are not getting in. It’s the same with antibodies. They are very specific in what they bind to.
Here is what researchers figured out over the course of a number of years. They figured out how to take the attachment part of an antibody, right on the tip of it, what would be the key to your key. They figured out how to take the attachment part, come up with a very specific one that they want, then take the DNA that encodes that attachment part and insert that DNA into a T cell, the attack cell that I mentioned.
Normally, antibodies and T cells are separate. They may work in conjunction with each other, but they’re separate from each other. T cells don’t make antibodies; antibodies aren’t attached to T cells normally, but researchers figured out how to get the DNA into the T cell so that the T cell can produce the attachment part of antibodies and put it on its own surface. Now you have this T cell, an attack cell, with a very specific antibody binding tip on it, so now what happens is it can attach itself to very specific targets and attack them. Pretty interesting!
So with that figured out, what researchers did is they were able to take T cells from an individual who had cancer, use those T cells to insert the DNA that would encode for the antibody that would bind to a specific protein on that person’s cancer, then grow a bazillion of those T cells into this army of T cells ready to go and put them back into the person with cancer. Now what happens is these T cells attach to the cancer cell using the attachment point from the antibody, and then they go into attack mode and they wipe out the cancer.
This is incredibly fascinating because it pulls together genetics, molecular biology, biological engineering, working with living systems to take the T cells out and then re-infuse them. It is an incredibly, fabulously sophisticated and elegant system, and at least in the one cancer that it has been approved for by the FDA, it is also fantastically successful for people who otherwise were at the end of their rope, who had really nothing left.
So that is the science behind CAR T cell therapy. Super cool, super amazing, and I think probably in upcoming years this will be something that expands for the treatment of other cancers as well. Hopefully this will be a topic that you never need any personal involvement with, but it’s just so amazing that I had to share it with you.
I hope you’ve enjoyed this. If you want to look at perhaps some more pragmatic videos that may be more useful for you, go to our website, sentinelprimarycare.com. For Sentinel Primary Care in Brier Creek in Raleigh, I’m Dr. Patrick O’Connell.