Antibodies, also called immunoglobulins are large y-shaped proteins which function to identify and help remove foreign antigens such as viruses and bacteria.
In mammals there are five main types of antibodies including: IgA, IgD, IgE, IgG, and IgM. There are 4 IgG and 2 IgA subtypes present in humans.
Antibodies are created by plasma cells which are derived from the B-cells in the immune system. Due to the fact that antibodies exist freely in the bloodstream or bound to cell membranes, they are said to be part of the humoral immune system.
Every different antibody recognizes a specific foreign antigen. This is because the two tips of its “Y” are different to each antibody are allow different antibodies to bind to different foreign antigens. When the antibody binds to a bacteria, it tags the microbe or virus for attack by the immune system such as killer T-cells. Sometimes, antibodies can directly neutralize the foreign body. The production of antibodies by B-cells is the main function of the humoral immune system.
Autoimmune disorders can usually be traced to antibodies which bind the body’s own proteins or epitopes, and these types of antibodies can be detected through serological blood tests. Due to the amazing specificity of antibodies, they have some important practical applications in both medicine for the detection of HIV and other viruses in blood, and in research to purify and detect proteins in the study of molecular biology. For example, currently medicine is using biotechnologically designed monoclonal antibodies which work as an antibody therapy. These methods are being employed recently and are the result of numerous clinical trials in a number of diseases including cancer, and rheumatoid arthritis.