The immune system protects the human body from parasites, viruses, pathogenic bacteria, toxic products of their vital activity and not only. It is necessary to distinguish the body's resistance to congenital type infections (non-specific) from the acquired type (specific). Congenital defense against bacteria due to heredity. The mechanisms of nonspecific (or congenital) immunity to many pathogenic factors are phagocytosis and the inflammatory process.
Specific immunity is an accurate recognition system of the body. Its action is aimed at reading information from pathogenic aggressors - antigens, and memorizing them. Intracellular acquired resistance to infections works to protect the inner space of cells. Humoral immunity carried out in extracellular fluids.
First, infection of the body with protective cells, macrophages that freely migrate in the intercellular fluid, bind to the antigen, identify it. Auxiliary cells T-helpers are connected to the induction of the protective reaction and activate B-lymphocytes. Soon, the lymphocytes mutate, turn into plasmocytes, which produce specific antibodies. This forms the acquired humoral immune response with the formation of specific memory cells that store information about the antigen. When a second type of antigens enters the body again, a powerful antibody response is triggered, causing, for example, allergic conditions.
Humoral immunity depends on the ratio of T-helpers and T-suppressors formed in the bone marrow, in an optimal variant 2: 1. This ratio is violated with AIDS with the exact opposite of 1: 2, because T-helpers affected by the virus die. Therefore, any infection remains unrecognized, which is the cause of death of the body.
Classification of antibodies in the intercellular environment of the body
Environmental antigens are so diverse that to combat them, the humoral system is capable of producing 108 different specific antibodies. Many sections of DNA proteins are unique in their structure; they determine the diversity of antibodies.
Five classes of immunoglobulins provide a stable protective response to antigens.
1. Class G.
Class G immunoglobulins in the human body are larger than all others (up to 18 g per liter). Ig G fight toxins, bacteria, viruses, are in the blood and lymph.
2. Class A.
Class A immunoglobulins are serum, those that circulate in the blood, and secretory, in gland fluids. Globular serum proteins are responsible for overall immunity. Immunoglobulin secretion provides local protection of the body against infections, toxins, creating a barrier to their mass penetration. The humoral immunity provided by IgA antibodies is manifested in acute respiratory infections, pneumonia, and infection of the housing and communal services.
3. Class E.
Class E immunoglobulins are directly involved in the decay of toxins, in the phagocytosis of foreign particles, their bonding and neutralization, destroy the upper layers of bacterial cells. The content of Ig E in intercellular fluids increases with infectious diseases in adults and children. The Ig E group also includes antibodies to red blood cells of foreign origin.
4. Class D.
Class D immunoglobulins circulate mainly in the membranes of blood plasma cells, and their concentration in serum is relatively low. The function of Ig D proteins is to indicate the necessary specialization for B-lymphocytes; they are included in the work of autoimmune processes.
5. Class M.
Ig M immunoglobulins circulate inside the vessels, transform from plasmocytes in cases of the initial entry of antigens into the body. The Ig M protein includes potent humoral immunity in bacteremia.