Immunoglobulin E and its physiological significance

Immunoglobulin E and its physiological significance are issues that need to be addressed. For today, several types of immunoglobulins (antibodies) are known . There are several types of antibodies that differ in the nature of the action and the mechanism of anti-infective immunity. Antibodies provoke precipitation and flocculation of dissolved bacterial products, agglomeration and agglutination of corpuscular antigens (spirochetes, viruses, protozoa and bacteria). On the cell membrane of vibrios, trypanosomes and spirochaetes, specific complexes of immunoglobulins with complement are fixed, which causes platelet adsorption. As a rule, these infectious agents are delayed in the lymphoid tissue. Immunoglobulins of classes M and G together with complement can hydrolyze spirochetes, trypanosomes, bacteria and viruses.

The effect of antibodies on the pathogen is suspended if it penetrates the cell, and its antigens are not expressed on the surface of the cell. Immunoglobulins can enhance or weaken the immune resistance of the body. The antigen-antibody complex, which contains an excess of antigen, has a stimulating effect, and a complex with an excess of antibodies causes the opposite effect. Most often, immunoglobulins are the cause of autoimmune and allergic complications.

Immunoglobulin E is synthesized mainly in the cells of the mucous membranes of the respiratory, gastrointestinal tract, as well as in regional lymph nodes. For the first time, as an independent class, immunoglobulin E was identified in 1966, and in 1968 the VOZ recognized immunoglobulin E as an independent class of immunoglobulins.

Proteins of this class are found in humans, primates, and some laboratory animals. Most of the molecules of immunoglobulin E are associated with mast cells of the skin and basophils. Since under normal conditions the concentration of immunoglobulin E in human blood serum is only a few nanograms per milliliter, the basic ideas about the structure of this molecule are obtained only on the basis of the study of several myeloid proteins. The very low level of immunoglobulin E in the blood serum is evidently due to the fact that it is able to "attract" to the surface of cells and bind firmly to mast cells and basophils.

It is believed that IgG is the main class of immunoglobulins, which produce mast cells and basophils for participation in allergic reactions. The level of this protein in the blood serum of patients with allergies increases and usually exceeds 350-800 U / mg. Total immunoglobulin E norm in children under 12 months is up to 15 U / ml. Immunoglobulin E plays an important role in immediate-type hypersensitivity reactions. Immunoglobulin E norm in adults is from 0 to 120 U / ml.

According to modern ideas, the main function of immunoglobulin E is to protect the mucous membranes of the body by activating local factors of blood plasma and effector cells. Infectious agents are able to break through the line of defense that is formed by class A immunoglobulins. After that, viruses or bacteria on the surface of mast cells bind to specific immunoglobulins of class E, as a result of this interaction, mast cells get a signal for the isolation of vasoactive amines and chemotactic factors, which in turn causes The influx of circulating blood Ig class G, complement, eosinophils and neutrophils. The eosinophilic chemotactic factor, which is released from mast cells, promotes the accumulation of eosinophils and the destruction of helminths. It is suggested that immunoglobulin E, adsorbed on the surface of the parasite, attracts macrophages due to the presence of Fc receptors.