"There is still hidden mysteries in the bodyAlthough scientists have been looking at the tissues of the body through the microscope for more than 300 years, the researchers who participated in the discovery were surprised. This one find scientifically could mean the development of vaccines much more effective in the not too distant future. Experts from the Garvan Medical Research Institute of Australia have for the first time the "micro-organ"Located in the immune system who withholds the infections against which the organism has been vaccinated.
In a study published this week in the journal Nature Communications, researchers describe the discovery of this structure which, in addition to & # 39; shop & # 39; information about already administered vaccinesIt is also the place where immune cells come together to generate a quick response to an infection that the body has experienced before.
How was the discovery
This micro-organ was discovered when researchers analyzed the immune system in action during use an advanced high-resolution 3D microscope in live animals. This structure is packed with immune cells of many species and is strategically positioned to detect infections early, making it the ideal place to fight infection quickly & # 39; remembered by the body & # 39 ;.
"Since the Plague of Athens in 430 BC, we know that people who are exposed to an infection are often protected from getting the same infection again." It was noted that the survivors of the plague had developed an immunity. reinfection. However, there are still important questions about how the body can quickly fight when it detects an infection to which it has previously been exposed, "the researchers write in their article.
"The discovery is an important step to understand how to make better vaccines." Tri Phan.
In this way, the researchers They revealed the existence of thin and flattened structures which extend over the surface of the lymph nodes in mice. These dynamic structures are not always present: they only appear when necessary to combat an infection against which the animal was previously exposed.
How these "subcapsular proliferative foci" are formed
The researchers saw the structures they called FPS (subcapsular proliferative foci), within parts of the lymph nodes of patients, suggesting that they help to combat reinfection in both humans and mice. Use an advanced microscopy, the researchers were able to observe that different classes of immune cells met in this "FPS". Memory B cells, which contain information about the best way to attack the infection, are grouped there. Other types of cells that act as assistants did the same.
They also discovered that memory B cells switched to cells that fight infection. "This is an important step in the fight against infections, because plasma cells produce antibodies to recognize and defend the intruder and protect the body from disease," they said. "It was exciting to see the B cells of memory activated and grouped in this new structure that had never been seen before. We could see them move, interact with all of these other immune cells, and plasma cells become our eyes ", says Dr. Imogen Moran de Garvan, the first author of the study.
A matter of speed
The professor, Tri Phan, who led the research, notes that the FPS structures "perfectly placed to combat infections quickly, so they can stop the disease before it takes root"" When you fight against bacteria that can double in number every 20 or 30 minutes, every moment is important. To put it bluntly: if your immune system takes too long to collect the means to fight the infection, you die. This is why vaccines are so important. Vaccination trains the immune system so that it can produce antibodies very quickly when an infection reappears. Until now, we did not know how and where this happened, "he says.
The researchers claim that no one had seen the structures before because traditional microscopy approaches look at thin sections of 2D tissue that are chemically fixed to provide a snapshot in time. "The FPS is thinand it looks and disappears: both are attributes that obstruct detection with a conventional method, "they add.
"When we did a two photon microscopy, which allowed us to see the immune cells in three dimensions moving in a living animal, we could see the formation of these FPS structures, so this is a structure that has been time, but no one has seen it, because they do not have the right tools, it is a remarkable reminder that mysteries are still hidden in the body, although scientists have looked at the tissues of the body through the microscope for more than 300 years, "explains Dr. Moran.
For his part Phan says that the new discovery "an important step to understand how to make better vaccines"" So far, we have focused on making vaccines that can generate memory B cells. This new structure suggests that we now also have to concentrate on understanding how these B-memory cells are reactivated to produce plasma cells so that we can make this process more effective, "he concludes.