By Frank Augello
Due to the ongoing pandemic, everyone seems to be brushing up on (or for your random aunt on Facebook, discovering for the first time) the wonders of medical science. The vaccines against COVID-19 have rightfully been hailed as major breakthroughs since these mRNA-based vaccines employ a different mechanism of action than traditional vaccines to shore up the immune system against infection. While the COVID vaccines have been understandably getting the headlines lately, I’ll be discussing a different medical innovation with which I’m much more familiar, mainly because I work on it for forty hours (at least) per week: CAR T-cell therapy.
What is CAR T-Cell Therapy?
CAR T-cell therapy is a revolutionary gene therapy to treat cancer patients. The name stands for Chimeric Antigen Receptor T-cell therapy, and while those words together might sound vexingly scientific, the actual process is simple to understand. It’s a way of genetically reengineering the body’s own immune system to more efficiently and systematically recognize and eliminate cancer cells. For the specific types of cancer for which the treatment is approved, it boasts an overall 90% initial clinical remission rate, so essentially a 90% cure rate.
How Does CAR T-Cell Therapy Work?
When CAR T-cell therapy is prescribed, a sample of the patient’s blood is drawn and broken down into its component cells. Blood contains many different types of cells, several of which are major players in the body’s immune system, collectively known as white blood cells. One type of white blood cell, the T-cell is fittingly the most important part of this therapy, so they are isolated and continue on in the treatment.
T-cells are usually able to recognize and fight infection from foreign cells in the body, but cancer cells often appear the same as normal cells, which is why a key part of CAR T-cell therapy is teaching T-cells what the cancer cells look like. The treatment achieves this through genetic modification. Once the T-cells are isolated, new genes are introduced to the cells. The new genes direct the cells to produce proteins called chimeric antigen receptors, thus becoming CAR T-cells.
To break down the nomenclature, “chimeric” refers to how the new CAR T-cells contain several new genes to both recognize and fight cancer instead of just one new gene that would achieve only one of those goals, “antigen” refers to the specific markers on the cancer cells that the CAR T-cells are now trained to find, and “receptor” refers to how the CAR T-cells now can efficiently bind to, or receive, the antigens on the cancer cells in order to eliminate the cancer from the body.
Essentially, the chimeric antigen receptors produced by the modified T-cells serve many functions, allowing the T-cells to recognize the specific cancer cells, bind to the cells, activate cancer-killing mechanisms, and bring in reinforcements from other types of immune cells. Once the CAR T-cells have these new superpowers, they are reinfused into the patient’s body. Figuratively, the troops are sent into battle!
Currently, CAR T-cell therapy is FDA-approved to treat a handful of specific cancer types. The treatment’s potential is boundless, but in practice some challenges have arisen. T-cells can be trained to recognize any type of cancer cell, but the markers they’re directed to seek out need to be specific so that they don’t start attacking healthy cells. Also, some tumors are able to evade T-cells by masking their markers.
What Does the Future Hold for Other Medical Innovations?
Plenty of work needs to be done for CAR T-cell therapy to become a universal cancer treatment, but for now, this revolutionary therapy is a positive reminder that so many medical innovations are being used to treat previously incurable disorders that have plagued humans for generations. From cancer to COVID and everything in between (including fertility disorders), it’s only a matter of time before the countless scientists and medical professionals around the world discover the next great medical innovation.
Frank Augello is currently a Cell Processing Specialist II at Novartis, which manufactures a CAR T-cell therapy. He holds a master’s degree in bioengineering from the University of Pennsylvania and a bachelor’s degree in chemical and biomolecular engineering from Johns Hopkins University. He was also a contestant on the game show Jeopardy!
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