Chimeric antigen receptor T cell

Chimeric Antigen Receptor T-cell therapy (CAR-T cell therapy) is a type of immunotherapy that uses specially altered T cells—a part of the immune system—to fight cancer. A T cell is a type of lymphocyte, which plays a central role in the immune response. CAR-T cell therapy involves modifying the genes of a patient's T cells to produce "chimeric antigen receptors" on their surface. These receptors are synthetic and are designed to recognize and attach to specific proteins (antigens) on the surface of cancer cells.

Overview

The process of CAR-T cell therapy begins with the collection of T cells from the patient's blood. This procedure is known as leukapheresis. After collection, the T cells are sent to a laboratory, where they are genetically engineered to produce chimeric antigen receptors (CARs) on their surface. Once the T cells have been modified, they are multiplied in the laboratory to produce millions of CAR-T cells. The expanded population of CAR-T cells is then infused back into the patient's body, where they seek out and destroy cancer cells.

Mechanism of Action

The chimeric antigen receptors on the CAR-T cells enable them to recognize and bind to specific antigens on the surface of cancer cells. This binding activates the CAR-T cells, triggering a potent immune response against the cancer cells, leading to their destruction. The specificity of the CAR-T cells is determined by the antigen that the chimeric receptor is designed to target, making it a highly personalized form of therapy.

Applications

CAR-T cell therapy has shown promise in treating certain types of cancers, particularly B-cell leukemias and lymphomas, which are cancers of the blood and lymphatic system, respectively. It has been particularly effective in cases where other treatments have failed, offering hope to patients with advanced disease.

Risks and Side Effects

While CAR-T cell therapy can be effective, it also carries the risk of significant side effects. One of the most serious is cytokine release syndrome (CRS), a systemic inflammatory response that can occur when the infused CAR-T cells rapidly proliferate in the patient's body and release large amounts of cytokines. Other potential side effects include neurotoxicity, B-cell aplasia, and infections due to the immunosuppressive nature of the therapy.

Regulatory Approval

As of the knowledge cutoff date in 2023, several CAR-T cell therapies have received approval from regulatory agencies such as the U.S. Food and Drug Administration (FDA) for the treatment of certain cancers. These approvals mark significant milestones in the development of cancer immunotherapy and offer new options for patients with previously untreatable forms of the disease.

Future Directions

Research is ongoing to expand the use of CAR-T cell therapy to other types of cancer and to improve the safety and efficacy of the treatment. Efforts are also being made to reduce the cost and complexity of CAR-T cell therapy, making it more accessible to a broader range of patients.