Human antibodies are made of

Overview Your immune system is made of up a complex collection of cells and organs. The system works together to protect you from germs and helps you get better when you get sick. What is the immune system? Your immune system is a large network of organs, white blood cells, proteins (antibodies) and chemicals. This system works together to protect you from foreign invaders (bacteria, viruses, parasites, and fungi) that cause infection, illness and disease. Function What does the immune system do and how does it work? Your immune system works hard to keep you healthy. Its job is to keep germs out of your body, destroy them or limit the extent of their harm if they get in. When your immune system is working properly: When your immune system is working properly, it can tell which cells are yours and which substances are foreign to your body. It activates, mobilizes, attacks and kills foreign invader germs that can cause you harm. Your immune system learns about germs after you’ve been exposed to them too. Your body develops antibodies to protect you from those specific germs. An example of this concept occurs when you get a vaccine. Your immune system builds up antibodies to foreign cells in the vaccine and will quickly remember these foreign cells and destroy them if you are exposed to them in the future. Sometimes doctors can prescribe antibiotics to help your immune system if you get sick. But antibiotics only kill certain bacteria. They don’t kill viruses. When your immun...

Even though antibodies are important for fighting and preventing many infections, not all antibodies the body produces against a virus are effective. For example, different B cells in the body will produce multiple different antibodies that stick to different sites on the virus. But only attaching to some of these sites will actually inactivate the virus. So for a vaccine to work, it must produce this neutralizing antibody. Antibody Types The body usually first produces a Antibodies trigger your immune system to fight infection. They connect to a specific spot on a virus to inactivate it. IgM antibodies are the first antibodies the body produces. Later, your body makes IgG antibodies. These are critical for preventing future infection. How Antibodies Prevent Infections After an infection, certain T cells and B cells that can recognize the virus stick around for a long time. Then, when they are re-exposed to the virus (or another pathogen), these special memory cells recognize it quickly and respond. While researchers initially hoped plasma containing antibodies to the virus might help individuals recover more quickly from an infection, recent research has not suggested plasma is effective in treating COVID. While some trials continue, the World Health Organization does not currently recommend it. Synthetic Antibodies Researchers have developed synthetic (chemical) antibody therapies that might end up being an important part of treatment. Several monoclonal antibody product...

To develop an effective antibody treatment, researchers first have to identify the specific antigen causing the problem, then engineer antibodies to target it. Once a successful antibody is produced, researchers then replicate—or clone—the antibodies. How Monoclonal Antibodies Are Made The cell base used for cloning the antibodies can be made from mouse or human proteins, or a combination of the two, and is denoted by the final letters in the drug's generic name. • Murine monoclonal antibodies are made from mouse proteins. Their name ends in -momab. • Chimeric monoclonal antibodies are a combination of part mouse and part human proteins. Their name ends in -ximab. • Humanized monoclonal antibodies are made from small parts of mouse proteins attached to human proteins. Their name ends in -zumab. • Human monoclonal antibodies are fully human proteins. Their name ends in -umab. • • Humira (adalimumab): Produced entirely from human proteins, Humira is approved to treat RA, PA, AS, • • • Enbrel (etanercept): This receptor fusion protein inactivates TNF, and it is approved for treating RA, PsA, AS, polyarticular juvenile idiopathic arthritis (JIA), and plaque psoriasis (PsO). • Actemra (tocilizumab): The first monoclonal antibody biologic targeting IL-6 on the market, it is delivered by subcutaneous injection or IV infusion in the healthcare provider's office or clinic. It is also approved for two types of juvenile arthritis: JIA, systemic juvenile idiopathic arthritis, giant ce...

\( \newcommand\) • • • • • • Complex genetic mechanisms evolved which allow vertebrate B cells to generate a diverse pool of antibodies from relatively few antibody genes. Key Points • Virtually all microbes can trigger an antibody response. Successful recognition and eradication of many different types of microbes requires diversity among antibodies, a result of variation in amino acid composition that allows them to interact with many different antigens. • Antibodies obtain their diversity through 2 processes. The first is called V(D)J (variable, diverse, and joining regions) recombination. During cell maturation, the B cell splices out the DNA of all but one of the genes from each region and combine the three remaining genes to form one VDJ segment. • The second stage of recombination occurs after the B cell is activated by an antigen.In these rapidly dividing cells, the genes encoding the variable domains of the heavy and light chains undergo a high rate of point mutation, by a process called somatic hypermutation. • As a consequence of these processes any daughter B cells will acquire slight amino acid differences in the variable domains of their antibody chains.This serves to increase the diversity of the antibody pool and impacts the antibody’s antigen-binding affinity. • Point mutations can result in the production of antibodies that have a lower or higher affinity with their antigen than the original antibody. B cells expressing antibodies with a higher affinity f...