Types of immunity
- Congenital immunity
Innate immunity is the body’s ability to neutralize
- Acquired immunity
Acquired immunity is the body's ability toneutralize foreign and potentially dangerous microorganisms (or toxin molecules) that have previously entered the body. It is the result of the work of a system of highly specialized cells (lymphocytes) located throughout the body.
The acquired immune system is believed to beoriginated in jawed vertebrates. It is closely interconnected with a much more ancient system of innate immunity, which is the main defense against pathogenic microorganisms in most living things.
How innate immunity works
The innate immune system is much more evolutionarily ancient than the acquired immune system and is present in all plant and animal species, but has only been studied in detail in vertebrates.
Compared to the acquired immune systemthe congenital system is activated at the first appearance of the pathogen faster, but recognizes the pathogen with less accuracy. It does not respond to specific specific antigens, but to specific classes of antigens characteristic of pathogenic organisms.
In vertebrates, the main functions of the innate immune system are as follows:
- recruiting cells of the immune system to the area of penetration of the pathogen by producing chemical factors, including specific chemical mediators, cytokines;
- activation of the components of the complement system;
- detection and removal of foreign bodies from organs and tissues using leukocytes;
- activation of the acquired immunity system during antigen presentation.
How acquired immunity works
There are active and passive acquiredimmunity. Active can occur after an infectious disease or a vaccine has been introduced into the body. It forms in 1-2 weeks and persists for years or tens of years.
Passively acquired occurs on transferready-made antibodies from the mother to the fetus through the placenta or with breast milk, ensuring the immunity of newborns to certain infectious diseases for several months. Such immunity can also be created artificially by introducing into the body immune sera containing antibodies against the corresponding microbes or toxins (traditionally used for poisonous snake bites).
Like innate immunity, acquired immunity is divided into:
- cellular (T-lymphocytes),
- humoral (antibodies produced by B-lymphocytes; complement is a component of both innate and acquired immunity).
How does a person acquire immunity
- Antigen recognition
All leukocytes are capable of recognizing antigens and hostile microorganisms to some extent. But the specific recognition mechanism is the function of lymphocytes.
Thus, it is possible to recognize not onlyknown antigens, but also new ones, those that are formed as a result of mutations in microorganisms. When lymphocytes mature, they undergo a rigorous selection - the precursors of lymphocytes, whose variable receptors perceive the body's own proteins, are destroyed.
- Immune response
At the initial stage, the immune response occurs with the participation of innate immune mechanisms, but later lymphocytes begin to carry out a specific acquired response.
Thus, as a result of the immune responsea small group of inactive lymphocytes that have met their "own" antigen is activated, multiplies and turns into effector cells that are able to fight antigens and the reasons for their appearance. In the process of the immune response, suppressive mechanisms are activated that regulate the immune processes in the body.
- Neutralization
Neutralization is one of the easiestways of the immune response. In this case, the very binding of antibodies to foreign particles renders them harmless. It works for toxins, some viruses. For example, antibodies to the outer proteins (envelope) of some rhinoviruses that cause colds prevent the virus from binding to cells in the body.
- T killers
Killer T cells (cytotoxic cells) when activatedthey kill cells with a foreign antigen, to which they have a receptor, by inserting perforins (proteins that form a wide, non-closing opening in the membrane) into their membranes and injecting toxins inside. In some cases, killer T cells trigger apoptosis of a virus-infected cell through interaction with membrane receptors.
How to maintain immunity
A healthy lifestyle helps keep your immune system in working order: physical activity, hardening, proper nutrition, sleep and taking vitamins.
In addition, you can support the productioninterferons are produced by the body; there are special preparations for this. They are based on the scientific developments of Soviet scientists, improved taking into account modern technologies.
They are suitable for both prophylaxis during the season.colds, and to combat a wide range of viral infections: various acute respiratory viral infections, influenza and even herpes. The active substances of these drugs cause (induce) the synthesis of interferons in the body and maintain their amount at a level sufficient to protect against infections.
Antibodies for coronavirus
The shell of the coronavirus is a ball withthorns - this is the "crown". The main function of spikes (in English - spike) is to attach to the receptors of cells and ensure the penetration of the virus into the cell. A few days after infection, the body begins to produce antibodies that bind to different parts of the virus envelope, including the spines.
To fight coronavirus, the body synthesizes three classes of antibodies:
- immunoglobulins A (IgA, produced first in the acute phase of the disease, but have low specificity),
- M (IgM, are produced a little later, actively fight the virus and remain in the blood for about a month),
- G (IgG, appear 3-4 weeks after recovery and provide long-term immunity)
IgG, like antibodies of other classes,produced to different parts (antigens) of the envelope of the virus. Of the total volume of IgG antibodies produced, only a part is able to block the S-protein located on the spines of the virus and thereby prevent the penetration of the virus into the cell. It is these antibodies that doctors are most interested in.
How to determine a person's immune age
“Immune age is a human biological clock,which will help to identify in people a decrease in immunity in old age, to predict risks and determine preventive measures to maintain health.
Researchers at the Buck and Stanford InstituteThe university, as part of the 1000 Immunomes project, studied blood samples from 1001 people between the ages of eight and 96 years. The aim of the project is to find out how the signs of chronic systemic inflammation change with age.
Among the 50 investigated cytokines, the group noteda few that most influenced a person's iAge rating. In particular, the cytokine CXCL9 stood out. The substance usually directs immune cells to the site of infection. But among study participants, CXCL9 levels began to rise rapidly, on average around age 60. In subsequent experiments with cells in laboratory dishes, the team linked this age-related spike in cytokines to functional problems in endothelial cells, a major component of blood vessel walls.
On average, centenarians have an immune ageabout 40 years younger than what is considered the norm. Scientists have identified a single case of a superhealthy 105-year-old Italian with an immune system similar to that of a 25-year-old.
According to the authors of the work, on the basis of the system they have developed, it will be possible to create a new method for identifying the risks of developing age-related diseases that are associated with a decrease in immunity.
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