Antigen-antibody complex

Antigen-Antibody Complex is a molecular structure formed when an antigen binds to a corresponding antibody. This interaction is a fundamental aspect of the immune system's response to foreign substances in the body.

Formation

The formation of an antigen-antibody complex is a specific interaction, much like a lock and key. The antigen, or "key," fits into the antibody, or "lock." This is due to the unique structure of both the antigen and the antibody, which allows them to recognize and bind to each other. This process is also known as immunological specificity.

Structure

The structure of the antigen-antibody complex is determined by the specific interaction between the antigen and the antibody. The antigen-binding site of the antibody, also known as the paratope, binds to a specific part of the antigen known as the epitope. This interaction results in the formation of the antigen-antibody complex.

Function

The formation of the antigen-antibody complex is a crucial step in the immune response. Once formed, the complex can trigger various immune responses, including phagocytosis, complement activation, and cell-mediated immunity. These responses help to neutralize and eliminate the antigen from the body.

Clinical Significance

The antigen-antibody complex plays a significant role in the diagnosis and treatment of various diseases. For example, the presence of specific antigen-antibody complexes in the blood can indicate an ongoing infection or an immune response to a particular substance. In addition, the formation of these complexes can sometimes lead to pathological conditions, such as immune complex diseases.