Biology test “Blood and circulation. Protective properties of blood. Mechanism of action of the human immune system

Antibody formation and kinetics

Antibody formation occurs in response to the presence of a substance perceived by the immune system as foreign. The foreign entity is generally called an antigen. There are many different antigens that are presented to the immune system. Therefore, there are many antibodies formed.

The formation of countless antibodies follows the same general pattern. First, the immune system distinguishes between host and non-host antigens and reacts only against those that do not belong to the host. An example is rheumatoid arthritis, in which the host's response to self-antigens causes bone deterioration. Another example is heart disease, caused by a host reaction to a heart muscle protein.

Another feature of antibody formation is that antibody production can occur even when the host has not “seen” a particular antigen for a long time. In other words, the immune system has a memory for an antigenic response. Finally, antibody formation is a very precise reaction. Changing the protein structure only slightly can cause the formation of a different antibody.

The formation of antibodies depends on the processing of incoming antigen. Processing has three phases. The first phase is antigen equilibration between the inner and outer cells. Soluble antigens that can dissolve through cell membranes are able to equilibrate, but bulkier antigens that do not enter solution cannot. The second phase of antigenic processing is known as the catabolic breakdown phase. Here, cells such as macrophages take up the antigen. It is during this phase that the antigen is “presented” to the immune system and an antibody is produced.

The final phase of antigen processing is called the immune clearance phase. A bond occurs between the antigen and the corresponding antibody, and the complex is destroyed. The excess antibody circulates freely in the bloodstream. The antibody-producing cell of the immune system is called a lymphocyte or B cell. Presentation of a protein target stimulates lymphocyte division. This is called the inductive or lag phase of the primary antibody response. Some of the daughter cells will then produce an antibody to the protein target.

Over time, there will be many daughter lymphocytes and many antibodies circulating in the body. During this logarithmic or exponential phase, the amount of antibodies increases rapidly. For some time, the synthesis of antibodies is balanced by the breakdown of the antibody, so the concentration of the antibody remains unchanged. This is the plateau or stationary phase. Antibody production slows over several days or weeks. After this decline or death phase, a low baseline concentration can be maintained.

Lymphocytes retain memory of the target protein. If an antigenic target appears, as occurs in the second vaccination in the series, pre-existing “primed” lymphocytes are stimulated to divide into antibody-producing daughter cells. Thus, much more antibodies are produced the second time. This initial surge in antibody concentration is a secondary or anamnestic response. The higher antibody concentration can be maintained for months, years, or a lifetime.

Another aspect of antibody formation is a change in the class of antibodies produced. The specificity of the antibody response, although always quite specific, becomes quite specific in the secondary response. Although in a primary response an antibody may cross-react with antigens similar to the one produced in response, such cross-reaction occurs very rarely in a secondary response. The binding between antibody and antigen becomes more stringent in the secondary response.

Also Antigenic facial expressions; History of immunology; Immunoglobulins and immunoglobulin deficiency syndromes; Laboratory methods immunology; Tests for streptococcal antibodies. Among the many techniques used in forensic science are those that involve specific immunological recognition of proteins. The protein molecule that recognizes an antigen is called an antibody.

The antigen-antibody reaction is extremely specific. This allows the protein to be unambiguously detected. In addition, some antigen methods are very sensitive and therefore can quantify very small amounts of protein antigen.

Antibodies are also called immunoglobulins. The central core of immunoglobulin is more stable in construction. Antibodies are also used in laboratory tests, including the analysis of forensic samples, for blood collection, and for the identification of target microorganisms or toxins. The use of antibodies in forensic research is also called forensic serology. Blood typing is a common example of forensic serology. If blood cells have only the A antigen present, then in the presence of anti-A antibodies the cells may agglutinate.

Antibodies are also used to distinguish the blood of someone with a blood-related disease, depending on the presence of one or more abnormal enzymes in the blood. Other uses of forensic serology include detection of drugs, toxic compounds such as toxins, and past exposure to specific microorganisms.

Antibodies to animals. Antibodies are usually very specific, they combine only with specific types of antigens. Antibodies belong to a class of proteins called immunoglobins, which are produced by plasma cells in the blood as defense mechanism against invasion by parasites, in particular bacteria and viruses, either by destroying them or by making them harmless. The specificity of their binding reaction to a particular antigen is due to the configuration of a particular small region, known as the active site, on the surface of the antigens.

Thus, when a parasite enters the tissues of its host, antigens derived from the parasite each elicit a specific response depending on the specific antibody that binds to that antigen. This "recognition" by the host of the species or strain of parasite that has entered sometimes applies to other parasites if they share the same antigen. For example, the vaccinia and smallpox viruses have the same antigen, so immunity to one is immune to the other. Antibodies can persist in the body for a long time after the antigen has disappeared, thereby conferring immunity to any new infection by the same strain or variants of the parasite.

Vaccination or inoculation provides immunity to the body by injecting specific foreign proteins, which then stimulate the production of antibodies. Antibody. A complex protein that is produced in response to the introduction of a specific antigen to an animal. Antibodies are usually highly specific, combining only with specific types of antigens. The specificity of their binding reaction to a particular antigen is due to the configuration of a particular small region, known as the active site, on the surface of the antigens.

Thus, when a parasite enters the tissues of its host, antigens derived from the parasite each elicit a specific response according to the specific antibody that binds to that antigen. For example, the vaccinia and smallpox viruses have the same antigen, so immunity to one is immune to the other. It is important to note that each type of antibody protects the body from a specific class of antigen. When an antibody mixes healthy tissue with harmful substance, it is referred to as an autoimmune disorder.

The most common antibody is formed by basic structural units that have four chains: two light and two heavy. Although the general structure of antibodies is similar, a certain area protein varies greatly, resulting in the existence of millions of antibodies. This part of the protein is called the hypervariable region.

A wide variety of antibodies are produced by combinations of a set of genetic segments responsible for encoding different antigen binding sites. The latter then undergoes random mutations in that region of the antibody, increasing the diversity even further.

The numerous types of antibodies include, but are not limited to, antihistotic antibodies, antinuclear antibodies, and divalent antibodies. Immune system diseases. There are many diseases that are caused by disorders and the consequences of which are frequent infections. In some cases they are not very serious, but their recurrence may mean a subtle complication for the patient.

Some of the causes of these diseases can be found in the presence of certain rare cancers infected with viruses, fungi or bacteria of a certain type that directly affect the body. These disorders may be caused by a decrease in the number, inadequate functioning, or other disorders of the immune system.

It should be mentioned that immunodeficiency can occur from the moment of birth, in cases where it is genetically inherited or developed over many years by some external factors. Acquired immunodeficiency, which manifests itself in old age, usually caused by a specific disease. In some cases there is a slight deterioration in the defense system, but in other cases, the more severe the body's ability to cope with the infection may be destroyed.

This virus destroys white blood cells, which prevents them from responding to the threat of any external infection, making any simple illness a serious problem for this body. In childhood, one of the main causes of damage to the immune system is. If a child has malnutrition that is less than 80 percent of body weight, it is known that the immune system will be affected, and if she is 70, it will be severe. This happens because the nutritional deficiencies caused by this poor diet prevent the body from creating antibodies, becoming increasingly weak and vulnerable to any threat from the outside.