Immunoglobulin class switching, also known as isotype switching, is a biological process in which B cells, a type of white blood cells, change the class of antibody they produce while maintaining the specificity for a particular pathogen or antigen. Antibodies, or immunoglobulins, are proteins that play a crucial role in the immune system's response to foreign substances such as bacteria, viruses, or toxins.
The immunoglobulin class determines the functional properties of the antibody and its ability to combat different types of pathogens. There are five major classes of immunoglobulins: IgM, IgG, IgA, IgE, and IgD. Each class differs in its structure and function. IgM is the first antibody produced upon an initial immune response, while IgG is the most abundant antibody in the body and provides long-term protection. IgA is mainly found in mucosal areas, IgE is associated with allergic reactions, and IgD functions as a receptor on B cells.
During immunoglobulin class switching, B cells undergo a DNA recombination process known as somatic hypermutation. This process involves the rearrangement of genetic material within the antibody genes, resulting in the production of a different class of immunoglobulin. This allows B cells to produce antibodies with varying effector functions suited for specific immune responses.
Immunoglobulin class switching plays a crucial role in adapting the immune response to different types of infections and antigens. It enhances the effectiveness of the immune system by producing antibodies that are better suited to combat specific pathogens or to coordinate defense mechanisms in specific tissues or situations.
