Antibody class switching

Definition

Antibody class switching is a biological process in which a B cell changes the class (or isotype) of antibody it produces without altering the specificity for antigen. This allows the immune system to generate antibodies that are more effective at eliminating different types of pathogens.

5 Must Know Facts For Your Next Test

1. Antibody class switching occurs after B cells have been activated by an antigen and receive signals from helper T cells.
2. The process involves recombination of the constant region gene segments of the immunoglobulin heavy chain, not the variable region.
3. Class switching enables a single antibody-producing cell to produce different classes like IgG, IgA, or IgE while retaining antigen specificity.
4. Cytokines such as IL-4, IFN-gamma, and TGF-beta play crucial roles in directing which antibody class will be switched to.
5. Switching requires activation-induced cytidine deaminase (AID), an enzyme essential for initiating the recombination.

Review Questions

• What role do cytokines play in antibody class switching?
• Explain how antibody specificity is maintained during class switching.
• What enzyme is critical for initiating the recombination process during antibody class switching?

Related terms

B Cell Activation: The process by which B cells are stimulated by antigens and helper T cells to proliferate and differentiate.

Helper T Cells:

A subset of T lymphocytes that assist other white blood cells in immunologic processes, including helping B cells undergo class switching.

Cytokines:

Small proteins released by cells that have a specific effect on interactions and communications between cells, playing a significant role in directing immune responses.