Scientists of the Scripps Research Institute have discovered a previously unknown mechanism to regulate the body's response to pathogens, such as bacteria and viruses. The discovery casts doubt on long-accepted dogmatism in immunology and can affect many of its areas - from the appointment of vaccines to the causes of autoimmune diseases.

The results of a study conducted by Professor Michael McHeyzer-Williams (Michael McHeyzer-Williams), published in Nature Immunology.

The new research focuses on plasma cells, which are an integral part of the immune system. It is believed that they produce large amounts of antibodies - targeted proteins that fight disease. However, a new study shows that plasma cells also function on the principle of negative feedback, which affects the function of other higher-ranked immune cells called follicular helper T cells (TFH).

"Plasma cells are not only able to synthesize highly specific antibodies but also participate in the regulation of the process that creates a mature immune response," says Nadege Pelletier, research associate at McHeather-Williams Laboratory, the first author of the article.

Prior to this work, scientists considered plasma cells to be simple soldiers in the fight against "foreign invaders" who do not have the ability to control the course of future battles.

The immune system is the army of our body, and as a real army it identifies and destroys invaders, such as pathogenic bacteria and viruses that cause disease. The immune system must also recognize the cells of its own organism ("civilians") in order not to take them for invaders. The immune system consists of an innate (nonspecific) and acquired, adaptive (specific) components. The adaptive immune system provides the ability to recognize and memorize specific pathogens. It is capable of creating strong defenses when re-encountering a particular pathogen.

The McHeather-Williams Laboratory focused its attention on understanding the main events occurring during the immune response, especially on the regulation of processes involving B cells and T-helpers - the two main cell types of our adaptive immune system.

T-helpers are not able to kill or fight antigens directly. They are the "generals" of the adaptive immune system, and, like generals, they give orders in the form of activation and control of other immune cells so that they can do their job. B cells are responsible for fighting infection. The fate of B-cells is determined by random encounters between follicular T-helpers (a subtype of T-helpers specialized in reactions with B cells) and B cells specific for the same pathogen. They can either become plasma cells (factories for the production of antibodies) during the acute phase of the immune response, or create a memory of pathogens so that the next time the body can meet this enemy fully armed.

Plasma cells of the acute immune reaction phase are produced a few days after infection and fight with pathogens with antibodies with low affinity (affinity) to the pathogen. Plasma memory cells are developed later, and their role is to prevent re-infection: they secrete specific and extremely high affinity (tightly interacting) antibodies circulating throughout the body as sentinels ready to neutralize pathogens upon repeated infection so that the pathogens are eliminated before the onset of symptoms of the disease.

The unusual behavior of these highly effective and specialized antibody-secreting plasma cells was the focus of the McHeather-Williams Laboratory.

News. Gradusnik. En.

Keywords:.