How to Engineer CAR T Cells
CAR T cells are a type of cancer treatment that involves genetically modifying a patient’s own T cells to express a chimeric antigen receptor (CAR). CARs are designed to recognize and bind to specific antigens on cancer cells, which triggers the T cells to attack and kill the cancer cells.
Engineering CAR T cells is a complex and time-consuming process that involves several steps:
1. Isolate T cells from the patient
The first step is to isolate T cells from the patient’s blood. This is done using a process called leukapheresis, which involves removing white blood cells from the blood and then separating the T cells from the other white blood cells.
2. Activate the T cells
Once the T cells have been isolated, they must be activated in order to make them receptive to genetic modification. This is done by exposing the T cells to a chemical activator, such as phytohemagglutinin (PHA) or interleukin-2 (IL-2).
3. Introduce the CAR gene into the T cells
The next step is to introduce the CAR gene into the T cells. This is done using a viral vector, which is a virus that has been modified to carry the CAR gene. The viral vector infects the T cells and delivers the CAR gene into the cells’ nuclei.
4. Select the CAR-expressing T cells
Once the T cells have been infected with the viral vector, they must be selected for those that express the CAR. This is done using a process called fluorescence-activated cell sorting (FACS). FACS uses a fluorescent antibody that binds to the CAR to identify the CAR-expressing T cells.
5. Expand the CAR-expressing T cells
The selected CAR-expressing T cells are then expanded in culture. This is done by adding growth factors to the culture medium, which stimulates the T cells to proliferate.
6. Infuse the CAR-expressing T cells into the patient
Once the CAR-expressing T cells have been expanded, they are infused back into the patient. The T cells will circulate in the patient’s blood and will attack and kill any cancer cells that express the target antigen.
Clinical applications of CAR T cells
CAR T cells have shown great promise in clinical trials for the treatment of several types of cancer, including leukemia, lymphoma, and multiple myeloma. However, there are still some challenges that need to be overcome before CAR T cell therapy can be widely used.
One challenge is the development of CAR T cells that are specific for a particular type of cancer. CARs are designed to recognize and bind to specific antigens, but it can be difficult to design CARs that are specific for a particular type of cancer without also binding to other antigens. This can lead to off-target effects, in which the CAR T cells attack healthy cells as well as cancer cells.
Another challenge is the development of CAR T cells that are resistant to the immunosuppressive effects of the tumor microenvironment. The tumor microenvironment is often suppressive, which can make it difficult for CAR T cells to survive and function. Researchers are working on developing CAR T cells that are resistant to the immunosuppressive effects of the tumor microenvironment.
Despite these challenges, CAR T cell therapy is a promising new approach for the treatment of cancer. CAR T cells have shown great promise in clinical trials, and researchers are working on overcoming the challenges to make CAR T cell therapy more widely available.
