Someone is activating you

Does the substance created in the brain affect the immune system, which protects the body from external factors (such as bacteria, viruses and other disease agents)?  

 
 
Prof. Yitzhak Koch and Dr. Mia Levita. encourage or hinder
Does the substance created in the brain affect the immune system, which protects the body from external factors (such as bacteria, viruses and other disease agents)? A possible answer to this complex question emerges from a study recently carried out by a multidisciplinary team of scientists from the Weizmann Institute of Science. The scientists' research focused on a short protein (peptide) called GnRH-II, which is produced in the human brain, as well as in the brains of lower vertebrates. The fact that the peptide has been preserved and passed from one species to another through evolution for more than 500 million years indicates that it plays essential roles in the most basic life processes. What are these roles?

The research team that set out to crack this mystery, and find out whether GnRH-II can activate the immune system, included Prof. Yitzhak Koch, Dr. Mia Levita, research students Alon Chen, Yonatan Ganor, Shai Rahimipour, as well as Nurit Ben-Aroya from the Department of Neurobiology at the Weizmann Institute of Science. This series of experiments, described in an article recently published in the journal Medicine Nature, leads to the conclusion that the peptides from the GnRH family are able to activate T cells of the immune system, and even help them reach their target region.

In an experiment performed on human cells, the scientists discovered that both GnRH-II and GnRH-I (see box) bind to their receptors in the outer membrane of the T cells, activate them, and subsequently increase the expression rate of several genes in the cells, especially the expression of a gene that codes for The information necessary for the construction of a receptor that adheres to laminin. Laminin is a protein that is a central component of the intercellular tissue. Activated T cells adhere to it through special receptors scattered across their outer membranes, and thus they move from place to place in the intercellular tissue, when occasionally they stop, and then continue on their way on a "routine tour" to detect foreign invaders, or with the aim of helping damaged or attacked tissues. In the series In another experiment, the researchers injected T cells into the blood vessels of mice unable to produce GnRH-I in their bodies. The result: the number of T cells that penetrated the spleen and kidney of these mice was about half of the number of cells that penetrated these organs in normal mice. This experiment strengthened the scientists' hypothesis that in order to optimally penetrate certain organs, the T cells need the activation carried out by peptides from the GnRH family. the lymph nodes) are also helped by the "services" of peptides from the GnRH family on their way to establishing metastases. In a series of experiments designed to answer this question, the scientists found that these peptides indeed increase the expression level of the gene encoding the laminin receptor also in cancerous T cells, and suspected that this fact would help the cells in their proliferation processes in the body. And indeed, when they injected cancer T cells treated with one of the peptides from the HRnG family into normal mice, the researchers found that the proportion of these cells that migrated from the bloodstream and managed to penetrate the spleen and bone marrow (the target organs of these cancer cells) was double compared to the number of untreated cells that managed to do so. In other words, it seems that the peptides from the GnRH family, which help the cells of the immune system in their positive action, also help the cancerous T cells in their destructive work. The researchers say that it is possible that these findings may lead, in the future, to the development of medical applications that will allow the movement and function of T cells to be encouraged using peptides from the GnRH family. In this way, it may be possible to increase the activity of the immune system (in cases of illness and injury). It is also possible that by means of substances that block the activity of peptides from the GnRH family, it will be possible to delay the exit of cancer cells from the blood vessels, on their way to establish cancer metastases.

In a study carried out on human T cells, results were obtained showing that these cells can probably be activated by peptides from the GnRH family not only when these peptides are secreted from the ends of nerve cells in the brain. The scientists of the institute discovered to their surprise, that the T cells (both healthy and cancerous) are able to produce the peptide GnRH-II as well as its "brother", GnRH-I, and then secrete them into the extracellular fluid.

The peptide GnRH-I, which is similar to GnRH-II in 70% of its structure, is the sole regulator of the reproductive system in humans. Andrew Shelley and Roger Gilmin, who determined the structure of I-GnRH produced in the brain and discovered its role, were awarded the Nobel Prize in Physiology and Medicine for this work in 1977. On the other hand, the GnRH-II peptide has no real effect on the reproductive system, and its biological activities - Logics are still unknown.