Strong immunity is a prerequisite for human he alth. This system performs protective functions, preventing third-party pathogens from developing in the body. There are several types of immunity. They are characterized by different mechanisms of formation and impact. Only the coordinated work of all protective systems is able to prevent the penetration of pathogens into the body. What is adaptive immunity, will be discussed in detail later.
General characteristics
Innate and adaptive immunity are two components of the body's defense system. Together they are a qualitative criterion that shows the ability to withstand various kinds of external influences and diseases. Today, to assess it, such a thing as immune status is used.
Immunityallows you to maintain the integrity of the genetic information of the body throughout its life. It can be congenital and acquired. The first type of protective functions is also called genetic, or primary. It is formed in the child in the womb. This is the foundation for the development of subsequent defense mechanisms. Innate immunity depends on what diseases the parents and other blood relatives suffered from, how their body reacted to these pathologies.
Adaptive (acquired) immunity is formed throughout a person's life. There are several varieties of this type of protection. Acquired immunity is formed under the influence of natural and artificial factors. In the first case, various diseases affect the body, and certain forces are allocated to combat them. Information about protection in this case is stored in the body. This is active immunity.
The second type of protection is called passive, or artificial. An injection with a small amount of the pathogen is injected into the body. As a result, the immune system fights the pathogen, and information about this process remains for a certain time or for life in the body.
Peculiarities of acquired immunity
Innate and adaptive immunity operate continuously in the body. They perform essential functions. Adaptive (specific) immunity is the second phase of the body's defense reactions. Its characteristic feature is the fact that it is not inherited. It is formed throughout a person's life.
The acquired type of body defense is more intense than the innate barrier against various foreign microorganisms. Since the body adapts to environmental conditions through such reactions, this type of immunity is called adaptive.
This type of protection is formed during infectious diseases, poisoning. However, it is not stable. Not all infectious agents can be clearly remembered by the body. So, for example, a person who has had gonorrhea can get it again. The immunity that persists after this disease is weak and short-lived. Therefore, the likelihood of falling ill with this disease again is high.
However, some diseases, such as chickenpox, are only tolerated once by the body. A person cannot get sick with this disease anymore. The immunity that is developed after this disease is stable. However, it is not inherited. Parents who have had chickenpox can still contract the virus.
The more diverse the pathogens that enter the human body, the more different antibodies the body releases to fight them. This creates defensive reactions. Therefore, children who grew up in sterile conditions get sick much more often than babies who at a young age were in contact with various microbes and bacteria.
Main differences
To understand the features of different types of protective reactions of the body, it is necessary to consider in detail the comparative characteristics of innate and adaptive immunity. They differ in a number of indicators. Congenitalimmunity was the first defense system that was formed in vertebrates in the process of evolutionary development. Secondary (acquired) immunity appeared much later.
Innate immunity is the first to form in the human body. This is the basic foundation that he inherited from his parents. Based on this type of protection, the subsequent reaction of the body to the surrounding adverse factors is formed. This is a non-specific immunity that is passed from mother to child through the placenta and breast milk.
The acquired type of body defense is only 35-40% of the body's immune status. However, it is more intense. It acts faster and more actively on infectious agents and other pathogens. Innate immunity is weaker. He reacts to the onset of the disease more slowly. At the same time, the reaction that occurred to a particular foreign body is not remembered.
Acquired immunity is distinguished by the presence of a memory process. It is for this reason that such a barrier is more intense and faster.
Mechanism of action
The mechanism of adaptive immunity is quite interesting. This is a complex system that continuously functions in the human body. When a virus, bacterium or other pathogenic microbe enters the body, the immune system must first of all recognize and identify it. This is necessary to be able to distinguish the necessary, “own” bacteria from alien, destructive ones. Certain types of leukocytes are responsible for this function. They approach bacteria andcarry out the identification procedure.
Further, after collecting the necessary information, it is transmitted to other cells. Depending on what type of foreign microorganisms you have to deal with, a method is chosen to suppress the source of infection. For viruses, bacteria, allergens, poisons, the body produces different types of leukocytes. They approach the alien cage and consume it.
Information about what kind of immune response was given in this case is stored in the body's memory. There are special leukocytes that carry out training, transmit relevant information to new cells of the immune system that are just developing. This allows you to quickly respond to the pathology when it reappears.
In this system, each immune cell has its own special role. They work as a single, well-coordinated system, complementing each other. In this case, the reaction of the body to the causative agent of infection may be different. There is cellular and humoral adaptive immunity.
Types of immunity
The acquired type of protection can be of two types. This is cellular and humoral adaptive immunity. They perform different functions. Cellular protective factors act aggressively against foreign microorganisms. The cells that are produced by the body for this purpose destroy tumor, diseased, foreign cells.
For this, a mechanism such as phagocytosis is launched. The cell approaches the foreign object and then swallows it. Then he"digested", split in a special way. This function is performed by leukocytes. They belong to a certain group. Under the action of acquired immunity, T-lymphocytes are involved in the work.
An example of the impact of cellular adaptive immunity is the rejection of implants, transplanted organs and tissues. This type of protection protects the body from the development of tumors, infections. Lymphocytes that take part in the destruction of foreign objects are formed in the bone marrow. Then they move to the thymus, where they undergo a period of maturation and learning. It is for this reason that they are called T-lymphocytes. They leave the lymphoid organs many times. Then the cells come back. This allows you to quickly respond to the infectious agent.
Humoral adaptive immunity is provided by the production of antibodies. They provide protection. In this case, antibodies are immune factors. These cells are produced by B-lymphocytes. Their work is an allergic reaction to certain drugs, pollen and other components.
It is impossible to precisely define the boundary between humoral and cellular immunity. They are closely related and work together.
Main components and formation of the immune system
Existing factors of adaptive immunity consist of several key components. These include the functioning of the thymus, which produces T-lymphocytes, as well as the process of formation of antibodies. They also include cytokine synthesis and transfer factor.
To the main humoralfactors of adaptive immunity include the work of the thymus. It is also called the thymus gland. This process can be compared to getting an education in a tiered system. First, preschoolers are taught, then schoolchildren. After that comes the turn of higher education. The same thing happens with immune cells.
In the thymus, lymphocytes receive "preschool" and "primary secondary" education. These include T-suppressors, T-hellers, as well as T-lymphocytes of the cytotoxic type.
While a person is in childhood, their "training" is less intense. However, over time, the load increases. By the onset of puberty of the human body, the "learning" of lymphocytes becomes the most intense. This stimulates the immune system. As a person becomes an adult, the thymus gradually decreases in size. He starts to lose his activity.
Over time, it decreases in size. By old age, the production of T-lymphocytes decreases. Their training becomes less intensive. Therefore, in old age there is a decrease in immunity.
Antibodies
In addition to adaptive immunity cells, antibodies are also produced in the body. These are special protein molecules. They are synthesized by B-lymphocytes. This is the most active part of the immune system. Foreign cells have antigens. Antibodies bind to them. They have a certain shape. It corresponds to the configuration of the antigen. Once antibodies bind to foreign cells, they render them harmless.
These cells are also called immunoglobulins. There are several classessimilar proteins. The most important of them are LgM, LgG, LgA. Each of them performs special functions. By what immunoglobulins are found in the analysis, you can determine how long ago a person fell ill with this or that ailment. Some types of immunoglobulins are produced at an early stage, and others are produced at a later stage.
Macrophages
In addition to antibodies, macrophages also work with antigens. These are large adaptive immune cells that destroy piecemeal large areas of infected, foreign or damaged (dead) tissue. They accompany the processes of regeneration. After a macrophage comes into contact with a malignant or infected cell, it destroys it, but not completely. Some parts of the cell remain. These antigens form specific antibodies.
Antigens store information about a foreign cell. They transmit this information in the formation of other components of the immune system. After that, T-lymphocytes can easily recognize the foreign antigen. Immunity works in this case quickly. Cancer and infected cells are selectively destroyed. Specific memory cells are also responsible for this.
It is the preservation of information that helps adaptive immunity to persist throughout life. T- and B-cells in memory store information about a variety of pathologies that have developed in the body. This feature does not allow the disease to develop again. Some of the pathogens even go unnoticed by us. When they appear, the body reacts so quickly,that the infection sometimes does not have a single chance to win.
Cytokines
Considering the characteristics of adaptive immunity, it is necessary to pay attention to such a component as cytokines. They are also produced in the body along with special cells and antibodies. Cytokines act as signaling molecules. They play an important role at all stages of the immune response. There are several different kinds of these molecules.
Some cytokines are responsible for the reactions of innate and others of acquired immunity. This category includes many different factors. One of the most important is the transfer factor. It plays an important role in the formation of immunity.
Immune diseases
Adaptive immunity sometimes fails. This happens due to the negative influence of a number of factors. As a result, immune and autoimmune diseases can appear. In the first case, one or more components are absent or insufficiently produced in the protective system.
The immune response in this case is markedly reduced. As a result, the protection of the body becomes insufficient. Immunodeficiency can be congenital or secondary. The first category of disorders includes hereditary defects in the immune system. With secondary immunodeficiencies, it is required to reconsider the way of life. Factors provoking violations (poor nutrition, stress, wrong lifestyle, bad habits, etc.) need to be eliminated. At the same time, immunostimulants are also prescribed.
Autoimmune pathologies are characterized by the damaging effects of antibodiesimmunity directed at one's own body. As a result, inflammatory processes occur, caused by improper functioning of their own immunity. Cells lose the ability to correctly identify foreign pathogens. In the course of treatment, immunosuppressive drugs are used.
Having considered the features of adaptive immunity, one can understand its mechanisms, functions, and characteristic features. It is one of the most important components of the body's defense.
