Cancer is fighting back

The immune system's response to encountering a cancer cell opens with a promising step; But after a short time the immune cells almost disappear while the cancerous tumor continues to develop * also: vaccine against cancer

 
Prof. Gideon Barka. Balance of horror
 

A world could look and run much better without wars, attacks and defenses. Still, it is a fact that wars take place, and not only between nations and tribes, but also in the bodies of animals, including humans. Legions of immune system warriors are constantly patrolling inside our bodies, with the aim of protecting us from invaders such as viruses, bacteria and fungi. In the last decades, the immune system gained an important ally: the scientists who discovered and developed advanced weapons for the body's defense, including antibiotics, vaccine components, and more. In the future, the researchers hope to find ways to defeat the cancer cells by immune means as well.

Prof. Gideon Barka from the Department of Immunology at the Weizmann Institute of Science: "One of the fascinating questions in this field of research is why the body fails to fight effectively against cancer cells, which are, in many ways, an abnormal phenomenon in the body. In fact, the immune system's response to encountering a cancer cell opens with a promising step: it begins to produce killer T cells capable of eliminating the tumor. But after a short time these cells almost disappear, while the cancerous tumor continues to develop. Why and how does this happen?"

Prof. Barka has been researching for many years the fate of the T-cells, the soldiers of the defense army of the immune system. In the filing cabinet in his office are many files that contain findings and intelligence observations on the T cells. These observations and studies, spread over several decades, led to the somewhat frustrating conclusion that the cancer cells are not only a target for the attacks of the T cells, and in fact they are able to return Their attackers have a hair war. In this counterattack, the cancer cells use the same weapons that the T cells are equipped with, based on a lethal connection between a molecule called Fasl, displayed on the membrane of the attacking cell, and a death receptor called Fas, displayed on the membrane of the target cell. The connection between these two is the trigger that causes the target cell to lose itself in a process called "apoptosis".

Civil war
 

Recently, it seems that Prof. Barka and his colleagues, who studied lethal T cells in culture, managed to resolve the controversy. The findings of this study were recently published in the scientific journal Immunology. The research group included, in addition to Prof. Barka, the research student Ji-Hui, and Dr. Dalia Rosen from the Department of Immunology at the institute, as well as Prof. Paul Sundel from the University of Wisconsin who was then on sabbatical at the Weizmann Institute.

They discovered that both cancer cells and T cells of the immune system present the FasL molecules and Fas receptors on their membranes. This is how a "horror balance" is created that allows fighters from each "camp" to harm fighters from the other side, causing their death. This image creates expectations for a balance of power, but in reality, the cancer cells win over the cells of the immune system. The reason for this is that the T cells that meet cancer cells also harm their brothers, other T cells that fight against the cancer, as well as other types of T cells that can certainly be described as "innocent bystanders".

What is actually going on here? At first glance it seems as if the body is harming itself. But Prof. Barka actually finds immune logic in this phenomenon: "Self-elimination allows the immune system to 'reset' after an immune response against a foreign invader or against cancer cells. This is essential to 'turn off' the killer cells, an action without which our body would become more and more loaded with killer T cells - a clearly undesirable phenomenon." This new understanding is already influencing new therapeutic approaches. One of these is designed to determine a prognosis or optimal treatment for the patient depending on whether the FasL and Fas molecules are displayed or not on the cell membranes of the cancer tumor. In a parallel study, Prof. Barka is developing a research approach designed to test the degree of sensitivity of the cancer tumor to existing drugs.
 
 
 
Targeted elimination
The method of killing that the T cells of the immune system activate on their enemies has intrigued scientists for many years. The accepted hypothesis in this regard, first put forward by Pierre Hanckart of the US National Institutes of Health (NIH), said that T cells kill their target cells by secreting lethal substances such as the protein perforin, which breaks holes in the target cell's membrane, allowing enzymes to enter in and cause the breakdown of the genetic material and apoptosis. Prof. Barka and Dr. Dalia Rosen from the Department of Immunology at the Weizmann Institute of Science tried to discover traces of this process in animal research, but they were unsuccessful. Therefore, they hypothesized that the killer cells activate other means, such as receptors displayed on the target cell's membrane, and thus they convey to it a message that causes it to lose its sense of self. This theory has received reinforcements in the experiments of many scientists in different parts of the world, however, it is possible that two processes occur together in a kind of cooperation.
 

 Cancer vaccine

A significant step towards the development of a vaccine against certain types of cancer was recently carried out at the Weizmann Institute of Science in Rehovot, in a study in which professors Leah Eisenbach, Michael Feldman and Matti Friedkin collaborated, along with research student Ofer Mendelboim and other members of their research teams.  

A significant step towards the development of a vaccine against certain types of cancer was recently carried out at the Weizmann Institute of Science in Rehovot, in a study in which professors Leah Eisenbach, Michael Feldman and Matti Friedkin collaborated, along with research student Ofer Mendelboim and other members of their research teams.

The research aims to develop a way to inhibit the most dangerous process in the development of a cancer disease: the formation of cancer metastases.

The "border guard" cells of the immune system are supposed to identify - and destroy - cancer cells that drift in the bloodstream on their way to establish new cancer metastases. But in most cases a "security failure" takes place in the body: the cancer cells that are supposed to carry "identification signs"

Stand out, become sophisticated and present the "identification signs" in a way that reduces the ability of the "border guards" to notice them.

The "identification sign" of the cancer cells is, in fact, a complex structure that includes, among other things, a short segment of a certain protein. This segment differs from the corresponding segment in healthy cells, as a result of genetic mutation or other reasons.

Weizmann Institute of Science researchers discovered this protein segment, isolated it from lung cancer tumor cells, and successfully used it as a vaccine component. As a result, the immune system "learned" to recognize the "identification signs", and when cancer cells carrying those "signs" appeared before it - it attacked and destroyed them.