How Does the Immune Response Work?


What Is the Immune System?

The body has a built-in network called the immune system to help fight viruses, bacteria, fungi, and toxins. The immunity definition is “the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells.” The immune system is made up of two parts: the adaptive immune system, and the innate immune system. 

These two systems work in conjunction with each other. The adaptive immune system has been acquired throughout a person’s life, whereas a person is born with the innate immune system. When the body is exposed to microbes, the adaptive immune system produces antibodies to fight against foreign invaders and assists the body in eliminating them. The body then remembers the invaders and will produce immunity naturally. Antibodies are made in various parts of the body, including adenoids, bone marrow, lymph nodes, lymphatic vessels, Peyer’s patches, spleen, thymus, and tonsils. 

How Does the Immune Response Work?

If we didn’t have an immune system, our body wouldn’t be able to fight against the microbes that it’s exposed to. If you’ve ever wondered “How does the immune response work?”, you aren’t alone. The immune response is triggered when the body is introduced to a virus, bacteria, or fungi that it hasn’t previously been in contact with. When the immune system is working as it should, you don’t notice because it eliminates the pathogens. If the immune system is compromised, you may end up with an illness. Some germs the body is exposed to will only cause an illness the first time the body encounters them, such as chicken pox. If the body comes in contact with the chicken pox virus in the future, the immune response naturally kicks in and will prevent the body from becoming ill again. 

Activated Immune Response

The immune response can become activated by a variety of pathogens and microbes it doesn’t recognize called antigens. Antigens include the proteins found in bacteria, viruses, and fungi. As these antigens attach to immune system cells, the body triggers a series of processes. The cells in the body have proteins on their surface as well that don’t generally trigger an immune response. However, sometimes the body mistakes these proteins as foreign invaders and sets off an immune response in the body, causing an autoimmune disease. 

Why Is the Immune System Important?

The importance of the immune system is extremely significant, as without it, the body wouldn’t be able to fight off foreign invaders and would be open to attack from exposure to viruses, bacteria, and fungi. The immune system is constantly on the lookout for invaders, and when one is noticed, the body sends off a complex plan to eliminate the intruder. Interestingly, it can discern the difference between our tissue from foreign tissue and clears away dead and faulty cells. 

White blood cells (also called leukocytes) constantly flow through the blood and lymphatic vessels of the body looking for pathogens. When it identifies one, they multiply and send out signals for other cells to do the same. There are two types of leukocytes: phagocytes and lymphocytes. Phagocytes include neutrophils, monocytes, macrophages, and mast cells. Lymphocytes include B lymphocytes that produce antibodies and alert T lymphocytes. T lymphocytes destroy compromised cells located throughout the body while alerting other lymphocytes. 

What Are the 3 Immune Responses?

The immune system is designed with levels of defense mechanisms that pathogens need to cross to stop an infection from developing in the body. There are three types of immunity: physical barrier, nonspecific innate response, and specific adaptive response. The first line of defense is broken down into two categories: nonspecific resistance and physical/chemical barriers. The mucosa and skin of the respiratory and digestive tracts are considered physical barriers that prevent blood and tissue infections while eliminating pathogens. Tears, sweat, mucous, and saliva secreted by the mucosa or skin provide a physical barrier against invaders. 

Pathogens that are able to cross the physical barriers reach the next level of defense: the nonspecific innate response. The innate immune response includes proteins and immune cells to nonspecifically identify and eliminate any pathogen that enters the body. Phagocytes recognize and bind pathogens using a plasma membrane to surround pathogens inside the cell. Digestion in a phagosome breaks the pathogen down into fragments, eliminating the threat to the body. 

The third line of defense is the specific adaptive response where the body works at eliminating pathogens that it was previously exposed to. The adaptive immune system mainly includes lymphocytes and occurs throughout the body. 

How Does the Immune Response Prevent Infection?

While the immune system is always on alert, sometimes the body encounters viruses, bacteria, and fungi that it had previously come in contact with and successfully eliminated. Immune cells assist to help the immune system prevent infection. The innate immune system is non-specific and provides a general defense against harmful pathogens. The adaptive immune system is specific and makes antibodies for the body to fight certain germs that the body had previous contact with. As the adaptive immune system is constantly learning and evolving, it is able to help protect against viruses and bacteria that morph over time. 

The body can implement a rise in temperature called a fever to help kill microbes. As the body’s temperature rises it creates a hostile environment for microbes to live, killing off unwanted pathogens. The body’s repair response can also be triggered by a fever. When the body creates a fever, it can be helpful to not treat the fever so the body can naturally eliminate unwanted pathogens. 

How Does the Immune System Protect the Body From Disease?

As the immune system is always at work to prevent foreign invaders from taking hold of the body, it’s working day and night to prevent illness, infection, and disease. Immune system diseases are naturally halted by phagocytes and lymphocytes. The lymphatic system is a key player in the production of white blood cells, which protect the body from disease. The lymphatic system is a network of lymph vessels that gather excess fluids from tissues located throughout the body and then return them to the bloodstream. 

Lymph nodes and the lymphatic system act as a filter and confine harmful germs. When immune cells located in the lymph node recognize pathogens, they start to activate, duplicate, and leave the lymph node to find them and eliminate them. Lymph nodes often swell in response to an infection or invader, which is why doctors often monitor them for signs of disease.

How Does the System Work With Other Systems?

The immune system works in conjunction with the other body harmoniously to keep it running smoothly and efficiently. The immune system function is extremely important to the body’s overall health, as are the other body systems. The immune system works with the circulatory system, respiratory system, and skeletal system. The circulatory system is a wonderful example of how all the systems work together like a well-oiled machine. 

How the Circulatory System Works

The heart pumps blood through the vessels and travels to the digestive system where it absorbs nutrients from the last meal. Blood also carries oxygen to the lungs, where it is inhaled. The circulatory system also delivers nutrients and oxygen to other systems of the body while picking up any waste like carbon dioxide where it delivers it to the kidneys and lungs for excretion. 

Integrating the Respiratory System

The respiratory system relies on the circulatory system to distribute the oxygen it collects, while the heart muscles are unable to function properly without the oxygen they receive from the lungs. Even the seemingly unrelated systems work together to provide the body with what it needs. The urinary system helps with the skeletal system by removing waste produced by bone cells while the skeletal system protects the urinary system organs. The body’s systems work together to keep the body in homeostasis, or an internal state of balance and stability. 

Supplements Can Help

As we have learned, cells play a huge role in our overall health, supporting the immune system for proper function. They create energy, store and release oxygen, and communicate with each other to help keep our bodies at optimal health. Over time, our cells can become fatigued and get damaged due to the stress of everyday life. With the autophagy process, our cells are able to renew by cleaning cellular waste. The cells are detoxified and use the waste as energy through the process. By taking a high-quality supplement like spermidine, you can help assist your body naturally through removing damaged proteins from cells, providing building blocks and energy for cells, and encouraging regeneration of healthy cells. Give your body an extra boost by providing it with extra assistance through high-quality supplements. Your body will thank you with good health!

  • Don Moxley - Director of Applied Science

    Don Moxley is the Director of Applied Science at Longevity Labs. Moxley draws upon his career as an athlete, a sports scientist, and an instructor to lead and educate on the science of autophagy and longevity.