Nanoparticles against autoimmune diseases

A new way to treat allergic diseases

S.Kholin, Scientific.ruIt has been established that the introduction of biomimetic nanoparticles into the blood makes it possible to remove pathological antibodies responsible for the development of allergies from the body.

Modern medicine classifies all allergic diseases into four types (from I to IV). This is due to the complexity of the mechanisms of their development, the peculiarities of symptoms and the rate of occurrence. Despite the diversity, all types of allergic diseases have the same principle of formation, which is reduced to three links:

1. when a foreign antigen (protein, hapten, etc.) enters the body for the first time, antibodies immediately begin to be synthesized against it, the concentration of which in the blood gradually increases;
2. when the antigen re-enters the body, an immune reaction occurs with the formation of an antigen-antibody complex, which provokes the release of a large number of biologically active substances (allergy mediators);
3. mediators trigger an allergic process with all its characteristic manifestations: bronchial muscle spasm, vascular reaction, damage to cells and tissues, etc.

In other words, under the influence of foreign substances, immune hypersensitivity is formed, which can have serious and even severe (including fatal) consequences, for example, this happens with anaphylactic shock, bronchial asthma, Quincke's edema and other diseases.

All of the above concerns allergic diseases of type II – autoimmune diseases. They develop due to the fact that as a result of the adverse effects of external factors (drugs, chemicals, microbes, etc.), changes appear on the cell surface of some body tissues that give them antigenic properties. Because of this, the immune tissue begins to synthesize and secrete antibodies (more precisely, autoantibodies) into the blood, the action of which is directed against its own cells. A striking example of such a development is autoimmune hemolytic anemia (AIGA), in which antibodies accumulate in the blood that destroy their own red blood cells (red blood cells) and provoke their absorption by macrophages, resulting in anemia. According to a similar principle, immune thrombocytopenia, myasthenia gravis, subacute progressive glomerulonephritis, some types of cardiomyopathy, chronic aggressive hepatitis, etc. are formed. These diseases not only reduce the quality of life of patients, but also require long-term complex therapy in order to avoid serious complications.

For the treatment of the above type II allergic diseases, immunosuppression is widely used, that is, the suppression of the activity of the immune system by pharmacological drugs in order to inhibit the synthesis of antibodies. On the one hand, this reduces the likelihood of damage and destruction of blood cells and tissues by autoantibodies, on the other hand, such therapy has extremely dangerous consequences, because by reducing the activity of immunity, it makes the body practically defenseless against pathogenic bacteria, viruses and fungi. Therefore, at present, the search for new ways to reduce the production of autoantibodies or their speedy elimination from the body continues.

A group of scientists from the USA has developed a fundamentally new method for removing pathological antibodies from the blood in type II allergies. For this purpose, special (biomimetic) nanoparticles were obtained, which were disguised as erythrocyte membranes.

They were called nanosponge-RBC and proved that they serve as a target for pathological antibodies synthesized in allergy and, combining with them, form a complex that is absorbed by macrophages. Because of this, red blood cells remain intact, and can freely circulate through the vessels, performing their functions.

It is important to note that biomimetic nanoparticles do not suppress the activity of the immune system, that is, it retains the ability to protect the body from pathogenic microbes in full.

The effectiveness of the use of nanoparticles was confirmed in an experiment on laboratory animals in which autoimmune hemolytic anemia was simulated; at the same time, no toxicity or any other side effect of this therapy was revealed.

Thus, a fundamentally new method of allergy treatment is proposed by removing pathological antibodies from the body using masked biomimetic nanoparticles.

Article by Copp et al. The clearance of pathological antibodies using biomimetic nanoparticles is published in PNAS. 

Portal "Eternal youth" http://vechnayamolodost.ru03.10.2014