What are antibodies? The role of antibodies

Antibodies play a vital role in the human body, and some antibodies are beneficial or harmful to the body. Good antibodies can fight some viral cells in the body, while harmful antibodies will attack normal cells in the body.

Antibody (Ab)

It is an important effector molecule that mediates humoral immunity and is a glycoprotein produced by B cells that proliferate and differentiate into plasma cells after being stimulated by antigens. It mainly exists in body fluids such as serum. It exerts the function of humoral immunity by specifically binding to the corresponding antigen.

In 1986 and 1972, special committees of the World Health Organization and the International Union of Immunological Societies respectively decided that globulins with antibody activity or chemical structures similar to antibodies should be uniformly named immunoglobulins (Ig).

Antibody

Initially, electrophoresis was used to prove that the activity of antibodies in serum was in the gamma globulin portion, so antibodies were collectively referred to as gamma globulin. It was later discovered that not all antibodies are in the γ region; and that not all globulins located in the γ region have antibody activity.

In 1964, the World Health Organization held a special meeting and collectively referred to globulins with antibody activity and antibody-related globulins as immunoglobulins (Ig), such as myeloma proteins, abnormal immunoglobulins present in the serum of patients with macroglobulinemia, cryoglobulinemia, etc., and immunoglobulin subunits naturally present in normal people. Therefore, immunoglobulin is a concept of structural chemistry, while antibody is a concept of biological function. It can be said that all antibodies are immunoglobulins, but not all immunoglobulins are antibodies.

The main function of antibodies is to combine with antigens (both foreign and self), thereby effectively removing foreign matter such as microorganisms and parasites that invade the body. Antibodies are proteins produced in response to antigens and can specifically bind to antigens. Each antibody binds to a specific antigenic determinant. This binding can inactivate the antigen or it may be ineffective, but it can sometimes cause pathological damage to the body, such as the production of some autoantibodies such as antinuclear antibodies, anti-double-stranded DNA antibodies, and anti-thyroglobulin antibodies, which can cause harm to the human body.