How do antibodies neutralise pathogens?

Antibodies neutralise pathogens by binding to them, blocking their ability to infect cells and marking them for destruction by immune cells.

Antibodies, also known as immunoglobulins, are proteins produced by the immune system in response to an invasion by foreign substances, such as bacteria, viruses, and other pathogens. They play a crucial role in the body's immune response, helping to neutralise these invaders and prevent them from causing harm.

The process begins when a pathogen enters the body. The immune system recognises this invader as foreign and responds by producing specific antibodies that can bind to the pathogen. Each antibody is unique and matches the specific antigens (proteins) on the surface of the pathogen. This is why the immune system can respond to a wide range of pathogens - it produces a different antibody for each one.

Once an antibody has bound to a pathogen, it can neutralise it in several ways. One way is by blocking the pathogen's ability to infect cells. For example, if a virus has entered the body, antibodies can bind to the proteins on its surface, preventing it from attaching to and entering the body's cells. This stops the virus from replicating and spreading throughout the body.

Another way antibodies neutralise pathogens is by marking them for destruction. When an antibody binds to a pathogen, it acts like a flag, signalling to other immune cells that this is an invader that needs to be destroyed. These immune cells, such as macrophages and natural killer cells, then engulf and destroy the pathogen.

In addition, antibodies can also activate the complement system, a group of proteins that work together to destroy pathogens. When an antibody binds to a pathogen, it can trigger the complement system to create a pore in the pathogen's cell membrane. This causes the pathogen to burst and die.

Overall, antibodies play a vital role in the immune response, helping to neutralise pathogens and protect the body from infection. Their ability to bind to pathogens, block their ability to infect cells, and mark them for destruction by immune cells is key to their function.