Most people don't think about it, but our immune system is an amazing thing. In fact, it's the most complex network in the human body! The immune system is constantly battling invaders and making sure that we stay healthy. It does this by producing antibodies that can recognize specific antigens (proteins on the surface of cells). Antibodies are produced by B cells and are specific for one type of antigen. These antibodies use their variable region to bind with their matching epitope in order to destroy or neutralize it.
It's important to know that the immune system isn't just something that happens in your body. It's actually a collection of cells, tissues, and organs that work together to protect you from foreign invaders like viruses and bacteria. Some of these cells are found throughout your body; others live in one specific place.
One type of white blood cell called a B cell is responsible for producing antibodies (a type of protein). These antibodies help fight off harmful invaders like viruses and bacteria by recognizing specific things called antigens (substances on the surfaces of these invaders). Antigens can be anything from proteins on a virus' surface to fats on an invading bacterial cell wall—and once they're recognized by an antibody as being harmful, it attacks them until they're removed completely or their ability to cause infection has been neutralized.
B cells are produced in bone marrow and travel through blood vessels until they reach lymph nodes where they'll grow into fully developed immune cells known as plasma cells. When a B cell encounters an antigen it recognizes through its receptor sites on its surface membrane, this leads directly into activation where specialized chemicals within each plasma cell begin producing specific antibodies targeted at attacking whatever invader triggered recognition by its receptor sites."
The immune system is designed to protect the body against invaders, such as bacteria and viruses. It does this by recognizing and destroying foreign substances that enter your body, like bacteria or viruses.
The immune system is made up of white blood cells. These are produced in bone marrow and released into the bloodstream where they can then recognize external stimuli like bacteria and viruses.
An antigen is a molecule that triggers an immune response. Antigens are a type of protein, but they can also be made up of other molecules such as polysaccharides (complex sugars) or lipids (fats).
Antigens are specific to each type of antigen. For example, the protein in chicken eggs and the protein in rabbit meat are both antigens, but they're different proteins with different sequences and structures—and therefore trigger slightly different immune responses when your body encounters them. The epitope is the region of an antigen that is recognized by your immune system; it's usually composed of just two or three amino acids on any given protein chain.
When antibodies combine with their matching epitope, they can destroy or neutralize it. This process is called the humoral immune response, which takes place in our bodies' mucosal tissues and lymphoid tissues (such as spleen, tonsils and lymph nodes).
The antibodies that are secreted by B cells bind to an antigen and mark it for destruction by other components of the immune system, like macrophages. Antibodies will bind to antigens on pathogens such as bacteria or viruses, preventing them from entering into host cells. In addition, some antibodies can actually kill invading microorganisms directly themselves by binding tightly enough to cause lysis -- a form of cell death -- in the pathogen's outer membrane.
An antigen is a substance that generates an immune response. Antigens are proteins, carbohydrates, or polysaccharides and can be found on bacteria, viruses, or other cells. The specificity of antibodies to antigens is essential for their role in the immune system because it allows your body to respond appropriately to different types of invaders.
One example of this specificity can be seen with the Rh factor in blood types. If you have Rh-negative blood (you don't have any "Rh" antigen), your body can recognize Rh-positive cells as foreign and attack them as if they were infected by a virus or bacterium.
You might be wondering if the body makes antibodies that are specific for more than one type of antigen. The answer is no. This is because an antibody will only recognize its matching epitope, or region, on the antigen. For example, let's say that your immune system produces a certain antibody to fight against influenza viruses. That antibody will have a unique variable region that recognizes a specific epitope on the flu virus surface (the area of the virus visible to your immune system). If a different flu strain comes along with slightly different surface proteins than those involved with your original infection, then this new strain won't activate your original antibody because it features different epitopes than before.
The antibody will only recognize its own epitope. The variable region of the heavy chain can be changed by genetic recombination, which would be necessary if the body has encountered a new antigenic structure. But this is a rare event and is not necessary for most antibodies because most antigens have only one epitope that each antibody can bind to.
If an antigen changes its structure, it will no longer bind to an existing antibody (unless it changes into another form that still has one particular epitope). However, if something else happens with your immune system and you end up with a different set of antibodies in your plasma, then you could encounter this same antigen again but with different results since now it has a slightly different chemical makeup.
So, why are antibodies specific for one type of antigen? The variable regions of antibodies allow them to recognize their matching antigens. The variable regions are also called the Fc region, which stands for “fragment crystallizable domain” because this is what makes up the majority of a plasma cell and is involved in the production of antibodies.
We hope you enjoyed learning more about antibodies and how they are able to recognize their matching epitopes. The more you know about these fascinating little molecules, the better equipped you'll be to understand their role in our bodies!