Immunological memory. When encountering an antigen again, the body forms a more active and rapid immune response - a secondary immune response. This phenomenon is called immunological memory.
Immunological memory has a high specificity for a specific antigen, extends to both the humoral and cellular immunity and is caused by B and T lymphocytes. It is formed almost always and persists for years and even decades. Thanks to it, our body is reliably protected from repeated antigenic interventions.
Some lymphocytes have a short lifespan of only a few days. They say that these are living lymphocytes. Morphologically they belong to all three categories. Some of them live for a long time and even several years in humans. Long-lived lymphocytes are classified as small lymphocytes.
They are formed from pluripotent stem cells through two developmental lines. The lymphoid lineage produces lymphocytes, while the myeloid lineage produces phagocytes, that is, monocytes, macrophages and neutrophils and other cells. Like all blood cells, lymphocytes begin in the bone marrow. In the blood and tissues they appear as free cells, and in an organized form they are found in the thymus, spleen and lymph nodes.
The phenomenon of immunological memory is widely used in the practice of vaccinating people to create intense immunity and maintain it at a protective level for a long time. This is accomplished by 2-3-fold vaccinations during primary vaccination and periodic repeated injections of the vaccine preparation - revaccinations.
However, the phenomenon of immunological memory also has negative aspects. For example, a repeated attempt to transplant tissue that has already been rejected once causes a quick and violent reaction - a rejection crisis.
Lymphocytes can differentiate into different types cells and thus perform various functions in the body. Lymphocytes are very highly specialized cells and this is due to antigen specificity and proper function immune system. Each lymphocyte population has unique phenotypic differentiation antigens for phenotype and function.
T lymphocytes are formed in the red bone marrow, from where they move to the thymus, which multiply and acquire immune properties. They are said to be gracico-dependent when they go through it. They then move to other lymphopoietic organs, where they continue to divide and then enter the peripheral blood. Type B lymphocytes live up to 10 years and are responsible for detecting and neutralizing foreign agents to the body, which is involved in cellular immunity. Functional T lymphocytes are divided into:
Immunological tolerance is a phenomenon opposite to the immune response and immunological memory. It is manifested by the absence of a specific productive immune response of the body to an antigen due to the inability to recognize it.
In contrast to immunosuppression, immunological tolerance involves the initial unresponsiveness of immunocompetent cells to a specific antigen.
T lymphocytes are helper lymphocytes that secrete immunostimulatory lymphokines and suppressor lymphocytes that suppress lymphocytes that suppress the immune response. T cells are cytotoxic lymphocytes. . Few lymphocytes do not have markers on T and B lymphocytes on their surface and antigen receptors on their surface and are therefore called "null cells". In morphological terms, these are large cells that live for about a week with numerous cytoplasmic granules.
These cells have the ability to kill cells labeled with antibodies directed against their surface antigens. K cells are naturally present in the body without prior immunization. . These lymphocytes are produced in the lymphoid system in the red bone marrow, but unlike T lymphocytes do not pass through the thymus, so they are said to be dyslipidemic. B lymphocytes have a short lifespan, about 4-10 days. Produce immunoglobulins, which function as specific antibodies and participate in humoral immunity.
Immunological tolerance is caused by antigens, which are called tolerogens. They can be almost all substances, but polysaccharides are the most tolerogenic.
Immunological tolerance can be congenital or acquired. Acquired tolerance can be active or passive. Active tolerance is created by introducing a tolerogen into the body, which forms specific tolerance. Passive tolerance can be caused by substances that inhibit the biosynthetic or proliferative activity of immunocompetent cells (antilymphocyte serum, cytostatics, etc.).
Plasma cells are also called plasma cells. They arise as a result of differentiation of B cells under the influence of antigen. These are germ cells with a large amount of basophilic cytoplasm and a highly developed endoplasmic reticulum, which produces the synthesis of antibodies. They belong to the effector cells of the humoral response with a lifespan of several to several weeks. Compared to B cells, they do not have immunoglobulin receptors on their surface.
Macrophages are cells of myeloid origin that, after passing through the monocyte stage in the blood, pass through the endothelium of tissue vessels. Their characteristic feature is mobility and the ability to phagocytose. They occur as free, migrating, settling macrophages. Macrophages from different sites may differ in morphology and function. Macrophages of the spleen, liver, skin, bone marrow, connective tissue, and osteoclasts of brain microglia formed bones. macrophages. They play a very important role in specific and non-specific immune defense.
Immunological tolerance is specific - it is directed towards strictly defined antigens. According to the degree of prevalence, polyvalent and split tolerance are distinguished. Polyvalent tolerance occurs simultaneously to all antigenic determinants that make up a particular antigen. Split or monovalent tolerance is characterized by selective immunity to some individual antigenic determinants.
Since they have the ability to perform phagocytosis, they remove dead or dead cells from the body. In a specific immune response, an antigen is a foreign body, or more often a proteinaceous substance, that triggers the production of antibodies in the body. More Biological Dictionary of T-lymphocytes. They are also involved in responses to cells.
Dendritic cells include two types of cells with similar morphology but different origins. The first type of cells are myeloid cells, located on the skin and in the T-zones of the lymph nodes and spleen. They are of the same lineage as macrophages and are particularly effective at presenting T cell antigens. The second type is dendritic vesicular cells located in the lymph nodes of the lymphatic tissue. These cells are capable of long-term retention of antigens in the antibody complex on their surface.
The mechanisms of tolerance are diverse and not fully deciphered. There are three most likely reasons for the development of immunological tolerance:
1. Elimination of antigen-specific lymphocyte clones from the body.
2. Blockade of the biological activity of immunocompetent cells.
3. Rapid neutralization of antigen by antibodies.
Granulocytes and macrophages are derived from common bone marrow progenitor cells but differ in morphology and function. There are three types of granulocytes that perform different functions in immune responses. Neutrophils - migrating from the bone marrow into the bloodstream, neutrophils leave it after 6-24 hours to pass through the vascular endothelium into the tissue, where they die within 1-3 days. They are the body's first line of defense when they first reach the site of tissue damage caused by microbial invasion or other factors. Read more Echinacea - eukaryotic leukocytes with eosinophils. Eosinophils are mainly involved in parasite control. Read more Biology Dictionary makes up about 1-3% of white blood cells. Their number increases significantly with chronic inflammation and early allergic lesions. Read more Biology Dictionary and mast cells and protect the body from infections mainly from bugs, bacterial diseases or viral diseases. Basophil and mast cells - these two types of cells perform the same function, even if they belong to two different lineages. Basophil, derived from bone marrow, makes up about 0.5% - 1% of the total number of leukocytes. Mast cells are found mainly in connective and adipose tissue, as well as in the skin and mucous membranes. In contrast, basophils, which are already terminal cells, can continue to be mast cells. Cytoplasm Cytoplasm is the non-eukaryotic part of the protoplasm of a eukaryotic cell, which also includes the cell membrane. It consists of a primary cytoplasm called hyaplasia and organelles suspended in it. Read more The biological vocabulary of both types of these cells contains numerous granules, which include, in particular, heparin. It is a compound that counteracts blood clotting, which prevents the formation of blood clots, especially around areas of inflammation. These cells are involved in allergic reactions and inflammation.
- Neutrophils make up about 60% of all leukocytes.
- They usually die within a few hours of phagocytosis.
- They have multilamellar nuclei and numerous granulomas in the cytoplasm.
The phenomenon of immunological tolerance is of great practical importance. It is used to solve many important medical problems, such as organ and tissue transplantation, suppression of autoimmune reactions, treatment of allergies and other pathological conditions associated with aggressive behavior of the immune system.
Immunological memory. When encountering an antigen again, the body forms a more active and rapid immune response - a secondary immune response. This phenomenon is called immunological memory.
Continue Dictionary Biological substances are proteins produced by B lymphocytes and plasma cells that are capable of binding antigen. There are 5 classes of immunoglobulins. This helps to attract attention to the conjunctiva, mucous membranes and bronchitis. Antigens are high molecular compounds, often glycoproteins, that are recognized by lymphocytes and generate a response in the form of antibody production in a cellular or humoral response.
There are the body's own antigens and foreign antigens. They can create their own with both antigens and foreign complexes recognized by T lymphocytes, allowing for the presentation and recognition of antigens. Such phenomena underlie the induction of immune tolerance immune and immune phenomena.
Immunological memory has a high specificity for a specific antigen, extends to both the humoral and cellular immunity and is caused by B and T lymphocytes. It is formed almost always and persists for years and even decades. Thanks to it, our body is reliably protected from repeated antigenic interventions.
Immunity is immunity to an organism from pathogenic viruses, bacteria, protozoa, parasites or metazoans. Thanks to the effective resistance against what occurs in animals and plants, these organisms can live side by side. Anti-infection immunity is not the only function of the immune system. Organisms often undergo various types of cell mutations, which can cause them to multiply incorrectly and form cancer cells. However, due to the activity of immune cells, e.g.
Such cytotoxic mechanisms are limited. Immune cells, especially phagocytes, collect at the site of injury causing inflammation, which allows for the removal of particles and cells that have completed their service life. Resistance is the ability to maintain the risk of loss of integrity to dangerous agents of external origin, such as pathogenic microorganisms, or of internal origin eg. Tumor cells, aging or damaged cells. Maintaining the integrity of the body is possible through the interaction of the nervous and endocrine systems.
Currently, two most likely mechanisms are being considered formation of immunological memory. One of them involves long-term preservation of the antigen in the body. There are many examples of this: the encapsulated pathogen of tuberculosis, persistent viruses of measles, polio, chickenpox and some other pathogens for a long time, sometimes throughout life, remain in the body, keeping the immune system in tension. It is also likely that there are long-lived dendritic APCs capable of storing and presenting antigen for a long time.
Innate immunity is a type of nonspecific immunity, that is, in a way that the body receives as a result of contact with pathogens. It is produced due to the action of a microorganism on the body or by introducing a certain serum into the body. This resistance is divided into: active resistance - caused by travel illness or vaccine immunization. Antimicrobial resistance - This develops after a bacterial infection, but leaves behind a weak but short-lived resistance. The nature of this resistance and its durability depend on the chemical structure of the antigen responsible for its production. The most effective antigens are protein antigens, and lipid and polycystic antigens are slightly worse. They are counted in the kingdom of Monera. Read more Biological pathogenic dictionary. Cochrane immunodeficiency. This is a different type of resistance than described above. This continues as long as the infection persists and as long as the pathogenic microorganism is present in the body. Then an equilibrium is established between the organism and the organism, in which the organism is not strong enough to overcome the resistance of the microorganism, which produces enough to protect it from the consequences of another infection. This type of resistance is characteristic, for example, of tuberculosis, syphilis, and diarrhea.
- Acquired immunity is directed against a microorganism or against a toxin.
- Antimicrobial resistance is less durable than antitoxic resistance.
- Antiviral immunity - caused by pathogenic toxins and resistant.
Another mechanism provides that during the development of a productive immune response in the body, part of the antigen-reactive T- or B-lymphocytes differentiates into small resting cells, or immunological memory cells. These cells are characterized by high specificity for a specific antigenic determinant and a long life expectancy (up to 10 years or more). They actively recycle in the body, distributed in tissues and organs, but constantly return to their places of origin due to homing receptors. This ensures the constant readiness of the immune system to respond to repeated contact with the antigen in a secondary manner.
The phenomenon of immunological memory is widely used in the practice of vaccinating people to create intense immunity and maintain it at a protective level for a long time. This is accomplished by 2-3 times of vaccination during primary vaccination and periodic repeated injections of the vaccine preparation - revaccinations.
However, the phenomenon of immunological memory also has negative sides. For example, a repeated attempt to transplant tissue that has already been rejected once causes a quick and violent reaction - crisis of rejection.
Immunological tolerance- a phenomenon opposite to the immune response and immunological memory. It is manifested by the absence of a specific productive immune response of the body to the antigen due to the inability to recognize it.
Unlike immunosuppression, immunological tolerance involves the initial unresponsiveness of immunocompetent cells to a specific antigen.
Immunological tolerance is caused by antigens called tolerogens. They can be almost all substances, but polysaccharides are the most tolerogenic.
Immunological tolerance occurs congenital and acquired. Example innate tolerance is the lack of response of the immune system to its own antigens. Acquired tolerance can be created by introducing into the body substances that suppress the immune system (immunosuppressants), or by introducing an antigen in the embryonic period or in the first days after the birth of the individual. Acquired tolerance can be active or passive. Active tolerance is created by introducing a tolerogen into the body, which forms specific tolerance. Passive tolerance can be caused by substances that inhibit the biosynthetic or proliferative activity of immunocompetent cells (antilymphocyte serum, cytostatics, etc.).
Immunological tolerance is specific- it is directed to strictly defined antigens. According to the degree of prevalence, polyvalent and split tolerance are distinguished. Polyvalent tolerance occurs simultaneously in response to all antigenic determinants that make up a particular antigen. For split, or monovalent, tolerance characterized by selective immunity to some individual antigenic determinants.
Degree of manifestation of immunological tolerance significantly depends on a number of properties of the macroorganism and tolerogen.
The dose of the antigen and the duration of its exposure are important in the induction of immunological tolerance.. There are high-dose and low-dose tolerance. High dose tolerance caused by the introduction of large quantities of highly concentrated antigen. Low dose tolerance, on the contrary, it is caused by a very small amount of highly homogeneous molecular antigen.
Mechanisms of tolerance are diverse and not fully deciphered. It is known that it is based on the normal processes of regulation of the immune system. There are three most likely reasons for the development of immunological tolerance:
1. Elimination of antigen-specific lymphocyte clones from the body.
2. Blockade of the biological activity of immunocompetent cells.
3. Rapid neutralization of antigen by antibodies.
The phenomenon of immunological tolerance has great practical significance. It is used to solve many important medical problems, such as organ and tissue transplantation, suppression of autoimmune reactions, treatment of allergies and other pathological conditions associated with aggressive behavior of the immune system.
