Differences between Innate and Adaptive Immunity

Innate immunity, commonly referred to as genetic or natural immunity, is a type of immunity that is present at birth. This sort of immunity is genetically encoded, providing lifelong protection. The innate immune response is rapid and non-specific, which means that it does not behave differently depending on the virus or bacteria detected.

Physical barriers, chemical and cellular defences are all part of the innate immune system.

Physical barriers keep invaders out of the body. These include the skin and lashes.

Substance barriers are a form of defence mechanism that are capable of neutralising a potentially harmful chemical. Tears, mucus, and stomach acid are all examples of this type of substance.

The innate immune response’s cellular defences are nonspecific. These cellular defences recognise infections and potentially hazardous chemicals and take action to neutralise or eliminate them.

Another way to classify the components of the innate response is to divide them into external defences such as skin and tears and internal defences such as stomach acid and cellular defences. External defences act as a first line of defence against viruses, whilst internal defences act as a second line of defence.

The Principal Components of Innate Immunity are

(1) Physical and chemical barriers, such as epithelia and antibacterial substances produced on epithelial surfaces.

(2) Phagocytic cells (neutrophils, macrophages), as well as dendritic cells, natural killer (NK) cells, and other innate lymphoid cells.

(3) Blood proteins, including complement system components and other inflammatory mediators.

Adaptive Immunity

Adaptive immunity is a term that refers to an organism’s acquired resistance to a specific disease. As a result, it is also known as acquired immunity. Adaptive immunity is neither instantaneous, nor does it always endure the full lifespan of an organism, although it can. The adaptive immune response is characterised by the clonal growth of T and B cells, which produce large quantities of antibodies in order to neutralise or eliminate their target antigen.

The primary immune response occurs when the body encounters a novel disease pathogen for the first time. When B lymphocytes, or B cells, come into contact with a novel antigen, they produce antibodies directed against it in order to eliminate or neutralise it.

Simultaneously, B cells generate memory cells, a subset of B cells that persist for decades and are capable of detecting the pathogen upon future encounter.

The first time the body produces antigen-specific antibodies, this response takes longer than subsequent responses. When an organism comes into contact with the same pathogen a second time, the immune system responds more rapidly and robustly than during the original immune response. Memory cells are responsible for this improved speed.

Innate and Adaptive Immunity 

Immunity involves a diverse range of cell types. These comprise macrophages, neutrophils, eosinophils, basophils, mast cells, and dendritic cells in the innate immune response.

B cells (or B lymphocytes) and a variety of T cells (or T lymphocytes) are engaged in the adaptive immune response, including helper T cells and suppressor T cells. Both natural killer T cells and gamma-delta T cells are components of the innate and adaptive immune systems, respectively.

The innate immune system: rapid response and broad efficacy

The body’s initial line of defence against viruses is the innate immune system. Due to its universal response to infections and foreign substances, it is usually referred to as the “nonspecific” immune system. It works quickly: for example, it ensures that bacteria entering the skin via a tiny wound are rapidly recognised and removed. The innate immune system, on the other hand, is only partially capable of preventing viruses from spreading.

The innate immune system consists of

The skin and mucous membranes provide protection.

Immune system cells (defence cells) and proteins provide protection.

The adaptive immune system: Directly combating pathogens

When the innate immune system fails to eliminate the pathogens, the adaptive immune system takes over. It is directed specifically at the sort of germ responsible for the illness. It must, however, identify the germ first. This implies it responds more slowly than the innate immune system, but with more precision. Additionally, it possesses the ability to “remember” germs, allowing the adaptive immune system to respond more swiftly the next time a known germ is encountered.

This memory is also why many illnesses can only be contracted once in a lifetime, as your body grows “immune” afterward. The adaptive immune system may take a few days to respond the first time it comes into contact with the pathogen, but the body might respond promptly the second time. Typically, the second illness goes unnoticed or is milder.

The adaptive immune system is composed of the following components:

T lymphocytes in the connective tissue that connects the body’s cells

B lymphocytes, which are also located in the connective tissue that connects the body’s cells

Antibodies in body fluids and blood

Conclusion

The adaptive immune system, also known as acquired immunity, strategically mounts an immune response in response to specific antigens. Unlike the innate immune system, which strikes only when general dangers are identified, adaptive immunity is activated by pathogen exposure and utilises an immunological memory to learn about the threat and adapt the immune response appropriately. The adaptive immune response is significantly slower than the innate immune response, which is always prepared and ready to fight.