Yuki Kagoya: Using Cells as Medicine

2023/05/18

"Cell therapy," which uses cells as medicine, is currently attracting attention. Cells are the smallest units that make up our bodies, and because each one is a living thing that carries genetic information, creates various proteins, and generates energy, they are also called "living drugs." The concept of cell therapy itself has been established for a long time, with examples including blood transfusions to replenish blood cell components and bone marrow transplants for blood cancers such as leukemia. However, immune cell therapy, which has emerged in recent years, is characterized by the fact that cells are artificially processed outside the body to be improved for use as medicine. In particular, chimeric antigen receptor (CAR) T-cell therapy has shown high response rates for blood cancers that were previously difficult to treat, and is bringing about a paradigm shift in treatment strategies.

I am currently conducting research and development on cell processing technologies for use in treatments, including the aforementioned CAR-T cell therapy. The most distinct feature of cell therapy compared to existing therapeutic drugs is that while circulating through the body, it discovers lesions—such as cancer tissue—and then proliferates on its own, theoretically continuing to be effective until the target disappears. T cells, in particular, have a long lifespan among immune cells, and in successful treatment cases, it has been confirmed that CAR-T cells infused into the body persist for 10 years.

Furthermore, immune cell therapy is expanding its scope to diseases other than cancer. For example, in autoimmune diseases such as systemic lupus erythematosus, where immune cells recognize and attack the body's own cells, effective therapeutic results have been obtained with CAR-T cells that can attack B cells. The immune system originally has the role of continuously monitoring the body and maintaining its homeostasis. In that respect, it makes sense that it has broad applicability to chronically progressing diseases. Furthermore, the true strength of the immune system's monitoring system should be demonstrated in the phase of prevention—that is, preventing diseases from manifesting in the first place—and vaccines against infectious diseases are the prime example of that success. Regarding cancer, various studies have proven that it develops as a result of evading immune surveillance, and I believe that the ultimate goal is to establish preventive immunotherapy that artificially enhances this surveillance capability, for example, for high-risk individuals.