Chimeric antigen receptor (CAR) T cells are a form of immunotherapy in which T cells, a type of immune cell, is engineered to recognize and target the tumor. T cells are responsible for killing or lysing infections in a healthy immune system. Unfortunately, in the context of cancer, the immune system is suppressed by different proteins, known as cytokines. T cells in particular fail to detect rapid tumor proliferation and lose their anti-tumor function.

CAR T cell therapy engineers T cells to recognize and attack tumors. Commonly, T cells are taken from the cancer patient, engineered, grown, and expanded, then reinfused back into the patient. However, now CAR T cell therapy is moving beyond the field of cancer.

A recent paper in Nature Immunology, by Dr. Min Peng, and others demonstrated how CAR T cell therapy can be used to treat asthma. Peng is a professor and principal investigator in the Institute for Immunology at the Tsinghua University. His work focuses on harnessing the immune system to recognize and target diseases, including cancer. Research from his lab covers a broad range of topics including CAR T cell therapy, metabolism, T cell function biology, gene modification, nutrient sensing pathways, and immune cell reprogramming.

Asthma is a chronic inflammatory disease, similar to cancer. It affects millions of people globally with an estimated future increase in prevalence. Common symptoms include, coughing, wheezing, shortness of breath, chest pain, and obstructed airways. Asthma is seen as a very complex disease which needs personalized and varied treatments. Some medications including corticosteroids and bronchodilators help reduce asthmatic symptoms, but not all patients respond to these treatments. Peng and his team set out to determine how to overcome therapeutic limitations and treat asthma in patients that did not respond to standard-of-care.

Peng and his team discovered that one treatment or infusion of CAR T cell therapy prevented allergic asthma pathology for over a year. Specifically, researchers treated mice with CAR T cells designed to express continual cytokines that reduced inflammation of the airways. Researchers also used CAR T cells to target inflammatory innate immune cells known as eosinophils, which are critical in asthmatic reactions. By reducing eosinophil immune cells and excreting cytokines that reduce inflammation, Peng and others were able to prolong allergic asthmatic symptoms.

Peng and others demonstrated significant improvement in asthma with CAR T cell therapy, but there are still a lot of factors to consider before moving to the clinic. Although researchers demonstrated this therapeutic concept in human T cells, more work is needed before introducing it to patients. Feasibility and safety studies must first be conducted before moving to a phase I clinical trial. Unfortunately, adverse effects have yet to be assessed, and researchers are unsure of the long-term effects. Additionally, consideration when treating patients include specific biomarkers and clinical status of the patient to best determine who would ideally benefit from this therapy. Finally, this treatment is expensive to produce and requires many different resources to generate. However, with the excitement and success surrounding CAR T cell therapy, most insurance companies may eventually cover the entire cost for patients. Overall, this one-time therapy may be more cost-effective compared to continual biologic treatments over time. 

Paper, Nature Immunology, Min Peng, Tsinghua University