No. 10 Cancer Vaccine (Dendritic Cell Vaccine)

Dr.NakaGawa 🇯🇵中川医師

2023年1月21日 20:00

Dendritic cells, named dendritic cells because of their tree-like shape, have a strong antigen-presenting ability.

When foreign cancer cell antigens are added to the major histocompatibility complex (MHC) on the cell surface, cytotoxic T lymphocytes (CTL), which are potent attackers of cancer cells, can be efficiently induced. There are several methods for inducing cytotoxic T lymphocytes (CTLs), depending on the type of cancer antigen used. The main ones are the use of cancer peptides or the patient's own cancer cells.

Each has its advantages and disadvantages. First, the peptide method uses several to, in many institutions, as many as 26 peptides that are likely to be expressed by the cancer. This method is simpler than the method using cancer tissue, which is described below. However, it is not certain that CTLs are induced that completely match the target cancer cells, since it is like predicting which peptides will be expressed.

On the other hand, the use of actual cancer tissue induces the desired CTL. In reality, however, most of the patients who come for this treatment are already ineligible for surgery. The only way to obtain actual cancer tissue is to be admitted to a facility with adequate facilities for biopsy. However, it is rare that a major hospital that only offers insurance treatment will take such a risk. They are not willing to take on the risk of sticking a biopsy needle into a terminal cancer patient's cancer, much less making an incision in the patient's body. It is difficult for even doctors who understand this treatment to donate cancer tissue to other facilities, even if it is in conjunction with surgery. Specimens are treated very strictly. You can't give it to another facility without a reason. In reality, however, it is up to the attending physician. Even if the doctor is at the head of the department, he or she may be able to give a reason, but ultimately it is his or her "responsibility" to provide the specimens, so you understand that it is impossible if the doctor to whom you are providing the specimens does not only understand the treatment method, but also trusts you. This is especially true for large organizations. I don't want to be too negative, but on the contrary, once they trust you, it will go surprisingly smoothly.

Another disadvantage of this therapy is that it requires a large amount of blood and a heavy burden on the producer, as dendritic cells hardly increase in culture, and it takes about three weeks to complete the treatment.

In addition, it was recently discovered that there are two types of dendritic cells: one activates CTLs, which kill cancer cells, and the other activates regulatory T cells, which suppress CTLs.