immune system protects the human body from parasites, viruses, harmful bacteria, toxic products of their life and not only.One should distinguish the body's resistance to infections such as innate (non-specific) type of acquired (specific).Innate protection against bacteria due to heredity.The mechanisms of non-specific (or innate) immunity to many pathogenic factors are phagocytosis and inflammation.
Specific immunity is an exact Sensor detection system of the body.Its action is directed to the reading of information from pathogenic invaders - antigens and memorizing them.Intracellular resistance to infections acquired works to protect the inner space of cells.Humoral immunity carried out in extracellular fluids.
first infection the body defense cells macrophages, which are free to migrate to the interstitial fluid, bind to the antigen, identify it.By inducing a protective response connect auxiliary T helper cells and activated B-lymphocytes.Soon modified lymphocytes are transformed into plasma cells that produce specific antibodies.Thus formed acquired humoral immune response with formation of specific memory cells, storing information about the antigen.When the secondary antigen enters the body similar reaction run powerful antibody response provoking example, allergic conditions.
humoral immunity depends on the ratio produced in the bone marrow of T-helpers and T-suppressors, optimally 2: 1.This ratio is broken in AIDS exactly the opposite of 1: 2, after killing T helper cells affected by the virus.Therefore, any infection remains unrecognized, that is the cause of death of the organism.
Classification of antibodies in the body's extracellular environment
Antigens environment are so diverse that to deal with them humoral system is able to produce 108 different specific antibodies.Many sections of DNA proteins are unique in their structure, they determine the antibody diversity.
five classes of immunoglobulins provide a stable protective response to antigens.
1. Class G .
immunoglobulin G class in the human body over the rest (up to 18 g per liter).Ig G compete with toxins, bacteria, viruses, are in the blood and lymph.
2. Class A.
Immunoglobulin Class A serum are those that circulate in the blood and secretory glands in liquids.The globular serum proteins are responsible for the general immunity.Immunoglobulin secretion provides local protection against infection, toxins, creating a barrier to their massive penetration.Humoral immunity provided by antibodies IgA, manifested in acute respiratory disease, pneumonia, infection of the utilities.
3. Class E.
immunoglobulin E is directly involved in the breakdown of toxins in phagocytosis foreign particles, their bonding and neutralize, destroy the upper layers of bacterial cells.The content of Ig E in the intercellular fluids increases in diseases such as infection in adults and children.The group also includes Ig E antibodies to red blood cells of foreign origin.
4. Class D.
Immunoglobulin class D circulate mainly in cell membranes of blood plasma and serum concentration is relatively low.The function of proteins Ig D indicate the B-lymphocytes necessary specialization, they are included in the work of autoimmune processes.
5. Class M.
Ig M immunoglobulins circulating in vessels, transformed plasma cells in cases of primary antigens entering the body.Ig M protein contains a powerful humoral immunity during bacteremia.
