Immunity, Antibodies

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Immunity is a complex protective reaction of the body aimed at combating foreign substances and cells. Such foreign agents include bacteria, viruses, fungi, parasites, as well as altered body cells, such as cancer cells. All of these agents carry antigens - specific molecules that are recognized by the immune system as “foreign”.

When antigens enter the body, an immune response is triggered, resulting in the formation of antibodies and other protective reactions. Antibodies are proteins of the immune system that specifically bind to antigens and neutralize them. Main functions of antibodies:

1. Neutralization of antigens (toxins, viruses)
2. Opsonization - tagging of antigens for subsequent uptake by phagocytes
3. Activation of the complement system, which destroys cells with antigens

Antibodies are produced by B lymphocytes in response to antigen entering the body. There are 5 classes of antibodies: IgM, IgG, IgA, IgE, IgD. IgM antibodies are formed first, then they are replaced by more effective IgG. IgA antibodies predominate in the mucous membranes, IgE is involved in allergic reactions.

Thus, antibodies are the most important component of humoral immunity, providing specific protection of the body from pathogens and foreign substances. Their synthesis is regulated by the immune system in response to the penetration of antigens. By interacting with antigens, antibodies neutralize them and trigger a cascade of protective reactions in the body.