Antibodies are produced by specialized white blood cells called B lymphocytes (or B cells). When an antigen (a foreign molecule that triggers an immune response) enters the body, it binds to a specific B cell that has a receptor matching the antigen's shape. This binding activates the B cell, causing it to multiply and differentiate into plasma cells.
Plasma cells are antibody factories, churning out millions of antibodies specifically designed to target that particular antigen. These antibodies circulate throughout the bloodstream and lymphatic system, seeking out and binding to the antigen. This binding process neutralizes the antigen, preventing it from causing harm.
Here's a step-by-step breakdown:
- Antigen Recognition: B cells have unique receptors on their surface that can bind to specific antigens.
- Activation: When an antigen binds to a B cell receptor, the B cell becomes activated.
- Proliferation: The activated B cell undergoes rapid division, creating many copies of itself.
- Differentiation: Some of the daughter cells differentiate into plasma cells.
- Antibody Production: Plasma cells produce and secrete antibodies into the bloodstream.
Examples of antigens:
- Bacteria: These single-celled organisms can cause infections.
- Viruses: These tiny infectious agents can hijack cells to replicate.
- Toxins: These are harmful substances produced by bacteria or other organisms.
- Pollen: This substance from plants can trigger allergies.
Antibodies are essential for adaptive immunity, the part of the immune system that learns to recognize and target specific pathogens. By recognizing and neutralizing antigens, antibodies help to protect the body from infection and disease.
