Immune complexes are made by the binding of antibodies to antigens.
Immune complexes (ICs) are crucial components of the body's immune response. They are formed naturally within the body as part of the process to clear foreign substances or abnormal cells.
What are Immune Complexes?
Based on the provided information, immune complexes are formed by the interactions between antigens and antibodies. Think of them as clumps or lattices created when specific antibodies detect and attach to their corresponding antigens.
- Antigens: These are substances that trigger an immune response. They can be found on bacteria, viruses, fungi, or even within your own body (in autoimmune diseases).
- Antibodies: These are Y-shaped proteins produced by the immune system (specifically B cells) that recognize and bind to specific antigens.
The formation of an immune complex is essentially the physical linking of an antigen to one or more antibodies.
The Simple Process of Formation
The creation of an immune complex is a straightforward molecular event:
- An antigen (the target) is present.
- A specific antibody encounters the antigen.
- The antibody's binding sites attach to the antigen's surface.
- Multiple antibodies can bind to different sites on a single antigen, or multiple antigens can be linked together by antibodies, forming a complex structure.
The size and composition of the immune complex depend on the amount of antigen and antibody present. For example, a large amount of antigen might lead to smaller complexes, while an excess of antibody can result in larger, more stable complexes.
What Happens After Formation?
Once formed, immune complexes are typically cleared by specialized immune cells (like phagocytes). However, if they are not effectively cleared, they can deposit in tissues and cause inflammation and damage.
The provided reference notes that once formed, immune complexes can have further effects:
- They can induce NETosis (a process where neutrophils release a web of DNA and proteins to trap pathogens).
- They can directly activate neutrophils via Fc receptors (specific sites on immune cells that bind to the tail of an antibody).
- They can activate platelets.
- They can contribute to endothelial inflammation (inflammation of the cells lining blood vessels).
This shows that while their formation is a simple antigen-antibody interaction, immune complexes play a significant role in subsequent immune and inflammatory responses.
To summarize, making immune complexes is a natural outcome of the immune system's recognition process, where specific antibodies bind to target antigens.
