The first thing we must understand to talk about immunotherapy is what the immune system is.
The immune system is responsible for recognizing and eliminating malignant cells in the body , such as viruses, bacteria, fungi and toxins, through specialized cells. (Image of T and B Lymphocytes).
When these cells notice a foreign presence in the body, they are directed against them to eliminate the threat.
And what about cancer? Tumor cells are abnormal cells, which have the peculiarity of going unnoticed by the Immune System. They become invisible, and indestructible, because they use an enzyme that is found inside all cells, telomerase. This lengthens your telomeres so that your life is also lengthened. Thus, cancer becomes a threat.
Not that it is difficult to destroy tumor cells. There are toxic substances that we know can do it. The problem is selecting the right cells, without damaging the rest of the healthy cells. For this reason, treatments such as radiation therapy and chemotherapy have devastating side effects for the body, because the chemicals do not selectively affect cancer cells.
For this reason, the approaches to immunotherapy are totally revolutionary, and alien to conventional cancer therapies. The foundation on which immunotherapy is based is to use the immune system itself to kill tumor cells. And, for that, you have to remove the disguise from cancer, unmask tumor cells from among healthy cells.
How is cancer hiding?
As well. In order for the cells of the immune system, the T and B lymphocytes , to attack a cell, they have to recognize certain antigens that classify them as a threat. But tumor cells have proteins on their surface, called receptors, that prevent lymphocytes from recognizing the antigens that betray them as tumor cells. This is the cancer costume.
How do immunotherapy drugs work?
The immune system, in addition to a normal attack response against viruses, bacteria and fungi, has a type of adaptive response . That is, it is capable of recognizing new harmful agents; and also, he has memory, and is able to act again in front of them more forcefully the next time they appear. This is precisely how vaccines work.
Immunotherapy manages, through drugs, to disable the function of the receptors, it removes their disguise. And so the tumor cells become visible to the immune system, which attacks them.
The first time that an effective immunotherapy drug was found was in 2006, specifically, a drug capable of blocking the action of receptors for the CTLA-4 protein on T lymphocytes for metastatic melanoma cells.
Today, immunotherapy is available for other types of cancer as well, such as lung cancer and kidney cancer.
History of immunotherapy
But the history of immunotherapy goes back many years. The hypothesis about how immunotherapy works was first put forward in 1890 by surgeon William Coley.
Although it was not until 1975 when researchers George Köhler and César Milstein developed the first monoclonal antibodies. Finally, in 1984, this discovery earned them the Nobel Prize in Medicine.
But is immunotherapy the only alternative to eliminate the problem of chemo toxicity?
Not at all. A study published this month has managed to redirect the toxicity of toxic chemotherapy drugs, directly into the tumor cells.
Through exosomes, biomarkers that most cells secrete, a catalyst is introduced into tumor cells, to later release the anticancer toxin. The key to this system is that the exosomes are also camouflaged, and the tumor cells let the ‘secret weapon’ pass as if it were a Trojan horse, without suspecting what is inside.
The future of cancer therapies
Innovations in cancer therapies are significantly increasing the life expectancy of patients, with which many researchers believe that, in not a few years, cancer will become a chronic disease more often than a necessarily fatal disease .
Of course, not all patients are candidates for this type of treatment, such as immunotherapy. Cancer is a very complex set of diseases, and there are many genetic variables and markers that determine its characteristics. Hence, medicine is increasingly personalized, adapting to the peculiarities of each patient, to ensure the best treatment in each case.
