An autoimmune disease is, by definition, a disease caused by the body itself, which begins to work inappropriately by attacking healthy cells by mistake.
Type 1 diabetes, lupus, rheumatoid arthritis, multiple sclerosis, psoriasis are some examples of this type of pathology, which can be triggered at any time in life and have no cure.
Now, a team of scientists from Boston Children’s Hospital and Harvard University School of Medicine have identified the cause that triggers the body itself to turn against healthy cells, a discovery that could transform what is known so far about autoimmune diseases and how they are treated.
Scientists identified what would be the cause that triggers the body itself to turn against healthy cells
The reaction, discovered after four years of research in mice, was described as a “train out of control.” It would be something like a mistake that leads the body to develop a very efficient way of attacking itself.
The study focused on B cells (because B lymphocytes have an important role in regulating the immune system, under both physiological and pathological conditions). These are cells that make antibodies and program immune cells to defend themselves and attack unwanted antigens (or foreign substances).
The experts found a “kill switch” in the B cells of the rodents that distorted this behavior and caused autoimmune attacks.
Michael Carroll is one of the authors of the study and revealed that “once the body’s tolerance to its own tissues is lost, the chain reaction is like a runaway train. The immune response against the body’s own proteins , or antigens, it looks exactly as if the body is responding to a foreign pathogen. “
The problem arises when the body incorrectly identifies a normal protein as a threat
To study it, the researchers examined a mouse model with autoimmune lupus disease, considered a “classic” modality of autoimmune disease on which many others are based.
“Lupus is known as the Great Imitator because the disease can have so many different clinical presentations that it resembles other common conditions. It is a disease of multiple organs affected and with a plethora of potential antigenic targets,” explained Søren Degn, co-author of the job.
The scientists used fluorescent marker proteins to track different B cells in the rodents’ bodies. When B cells detect a foreign body – or something healthy that appears to be a foreign body – they move in groups called germ centers (this is why lymph nodes swell when we have a cold, for example).Scientists used fluorescent marker proteins to track different B cells in rodents (iStock)
The problem arises when the body incorrectly identifies a normal protein as a threat. When that happens, autoantibodies are produced that are very effective in damaging our own bodies.
The researchers found that “over time, the B cells that initially produce the autoantibodies begin to recruit other B cells to produce additional harmful autoantibodies,” says Degn.
Until now this has only been observed in mice, but researchers want to use this technique to see how this production of autoantibody B cells is regulated and accelerated.
Blocking the germinal centers could mean a break in the vicious circle created by autoimmune diseases since it would effectively block the short-term memory of the immune system.
And assuring that “this finding was a surprise,” Carroll concluded: “The discovery not only tells us that self-reactive B cells are competing within germ centers to design an autoantibody, but we also saw that the immune response expands to attack other tissues in the body, causing the epitope to spread at the speed of an out-of-control train. “
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