What is "CAR-T therapy" that teaches "killing" genetically engineered immune cells to kill cancer cells?

It is expressed as "silver bullet that shoots out only the prey targeted in the inside of his body and does not hurt the surroundings at all"CAR-T therapy"is. Although it is one of the immunotherapies in the experimental stage, it is approved by FDA in 2017 and it is likely to be used actually in the medical field.

Experimental Cancer Treatment That Terminates Rogue Cells Could Arrive in 2017 - Seeker

Genetically modified T cell therapy using chimeric antigen receptor (CAR)
(PDF file)http://s-igaku.umin.jp/DATA/61_04/61_04_02.pdf

Regarding CAR-T therapy, more than 100 clinical trials are conducted worldwide at the time of article creation. Among them, the approval is likely to decline in 2017 because biotechnology companiesKite PharmaIt is a treatment that is developing.

CAR-T therapy isT cellsDeveloped as a "killer T cell" that attacks cancer and developed "CTL therapy" that kills cancer cells by proliferation and activation.Since T cells that are originally present in the body do not attack cancerIf you activate and proliferate T cells vaguely, you can not fight against cancer. Therefore, in CTL therapy, treatment is done by culturing only the "matching type" T cells with the cancer cells that were in the patient's body and returning them to the body.

However, unlike viruses that are invading from outside the body, cancer cells are created by changing part of their bodies. Therefore, compared to virus, CTL therapy had a low probability of an immune response to cancer cells. In addition, cancer cells have an "immune escape mechanism" that resists immunity, and immune cells can not function normally due to the immune escape mechanismRecent research has made it clear.

I was born there, "CAR-T therapy" which genetically manipulates T cells collected from a patient, cultures it outside the body, and places it in the patient's body again. CAR of CAR-T therapy means the meaning of Chimeric antigen receptor (chimeric antigen receptor). T cells with chimeric antigen receptors kill cancer cells by releasing cytotoxic protein when they encounter cancer cells. In research published in 2013, CAR-T therapy has been done so farAntibody therapyIt is said that the antitumor effect is more powerful than it is.

ByZEISS Microscopy

However, CAR - T therapy is not effective for all patients, but at the moment it is planned to be done for patients who do not work well with existing treatment. Mr. Jeffrey Sosuman, a cancer specialist at the North Western Memorial Hospital, said, "Although handling may change with the passage of time, for now it is not the primary therapy for the disease, but the patient who failed the initial treatment It is a second-line treatment to be done against. "

It is also a prerequisite that patients with CAR - T therapy have sufficient physical strength to withstand several side effects. Side effects include high fever, low blood pressurePulmonary edema· There are various things such as heart failure, but in the worst case it is weakened to the point of death. These symptoms are caused by several immunotherapiesCytokine release syndromeIt is similar to.

Furthermore, although CAR-T cells target the protein contained in cancer cells as a target, if a targeted protein is found in other than cancer cells, even if it is a healthy cell, CAR - There is a danger of becoming a target of attack by T cells. There are many patients recovered by CAR-T therapy in clinical trials, but cases in which healthy cells were attacked during treatment have been confirmed among recovered patients. Increasing the accuracy to target the target is a subject of future research. Also, during the clinical trial conducted in 2016, six patients have died, and patients have died also in the clinical trial conducted by Kite Pharma in 2015, but the company reported that the cause of death in patients was There is no such thing.

And from the results of clinical trials, it has been found that CAR - T therapy is the most effective lymphoid tumor including acute lymphocytic leukemia and non - Hodgkin 's lymphoma. These cancer cells contain a protein called CD 19, but since other cancer cells have different proteins, it is necessary to reprogram the cells in order for CAR-T cells to attack there is. This part that enables CAR-T cells to distinguish target proteins seems to be a very difficult part.

Although there is still a problem in CAR-T therapy, if it proves to work well, it will be possible to obtain the effect by CAR-T therapy before the patient is exhausted with the existing antibody therapy It is. Also, since there are differences among individuals in the immune system, there is a possibility that treatment will be performed according to individual's immune system and cancer characteristics in the future in the form of replacing chemotherapy, surgery and radiotherapy I will.

ByJiri Linhart

in Science, Posted by logq_fa