CAR-T Cells: Engineering your immune cells to fight for you

Author

Neil Baugh
March 01, 2023

TLDR: Immune cells called T-cells are taken from you and engineered to fight your cancer more effectively by giving them tools to find it

Big Takeaways:

  • Cancer hides from the immune system, making it hard for immune cells to find and eliminate it

  • Some cancers have specific markers that distinguish them from healthy cells

  • Your T-cells can be isolated, given DNA instructions to produce surface receptors (CARs) that recognize the cancer-specific markers, and given back to you to fight the cancer

Cancer treatment has changed drastically in the past several decades. You’ve likely heard of chemo and radiation, and maybe even of immunotherapies, but might not have heard of newer treatments like cell therapies. CAR-T cells are immune cells that are isolated from the patient’s body and given specific surface molecules (CARs) that let them recognize and fight cancer cells.

Your immune system is primarily made up of different types of cells, broadly called immune cells. Each cell type plays a specific role in the fight against disease. One particularly important type for fighting cancer is the T-cell, which helps coordinate the other immune cells and directly attacks and kills cancer cells. However, cancer is notoriously effective at hiding from T-cells and making them less effective.

It’s important to remember that “cancer” is really a large number of individual cells. Your cells. Since these cells are your own cells gone bad, it’s hard to design a therapy that targets cancer without targeting your healthy cells. That’s where many of the side effects of chemo and radiation come from; while they kill cancer, they also kill everything else (just a bit less).

Different types of cancers sometimes have specific markers that distinguish them from healthy cells. Therefore, scientists can use these markers to engineer T-cell receptors (CARs) that recognize the mutated cancer cells, causing the T-cells to recognize them as a problem and kill them.

Once the marker has been found on your cancer, doctors can take a blood draw and isolate T-cells from it (step 1). These normal T-cells are then given a new piece of DNA that lets them make the CAR receptor for the cancer (2). After this, the cells are allowed to grow in the lab until a large enough dose is acquired (3) and then they’re put back into you to kill your cancer (4/5).

There are currently 6 CAR-T cell therapies approved by the FDA, all for different types of blood cancers. CAR-T therapies are a very active research topic and hopefully we’ll see some approved for other cancer types soon.

There’s a lot that goes into designing the CAR beyond just the target that it recognizes. If you’re interested in learning more, I encourage you to check out the links at the bottom of the post.

Image Credit: CAR-T Cells: Engineering Patients’ Immune Cells to Treat Their Cancers, National Cancer Institute

Some sources:

Neil is a Ph.D. Candidate at Stanford University studying Materials Science and Engineering. He works on combining different forms of drug delivery technologies to make more effective treatments.

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