B-lymphocytes in blood in men and women: types, functions, norm, what role?

B-lymphocytes are important for determining the presence of infection in the body. What other role, read in the article.

B-lymphocytes - These are cells of the human immune system, belonging to the so -called white blood cells (leukocytes). The main task of B-lymphocytes is to protect our body from infectious agents by developing protective antibodies.

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B-lymphocytes They are capable of turning into immune memory cells, due to which they start a quick and effective protective reaction in re -contact with the pathogen. From this article you will learn where B-lymphocytes are formed, how they ripen. How do these cells perform their immune functions? What is their normal concentration in the blood? You will find answers to these and other questions below. Read further.

Mechanisms of the human immune system: what is the role of lymphocytes in the blood?

The protective mechanisms of the human immune system can be divided into two main groups:

1. Congenital
2. Acquired

Congenital immunity - This is the first line of protection against pathogens. It is with its help that our body reacts to any infectious agent who is trying to attack us. Cisions of congenital immunity are primarily associated with the struggle from inflammation, the task of which is to eliminate the cause of the threat. The characteristic symptoms of inflammation include:

• Temperature rise
• Increased blood flow
• Tachycardia
• Various kinds of edema
• Pain

Other mechanisms of the early immune response also include:

• Dense bonds between the cells of the epidermis and the mucous membranes that prevent the penetration of microorganisms
• Natural protective reflexes, such as coughing, lacrimation, sneezing or diarrhea in the case of infection of the gastrointestinal tract
• The presence of bactericidal substances on the surface of the skin
• Social acid secretion with parietal cells of the stomach
• Constant colonization of the skin and mucous membranes of natural microflora

An innate immune response is very important in the early stages of protecting the body from pathogens. Unfortunately, in many cases this is not enough. Then our immune system reaches the second line of protection - acquired immunity.

Acquired immunity - The infection fights much more efficiently. The secret of its effectiveness is to develop a certain answer, i.e. individually adapted to each type of pathogen. Cells that produce such “individual” protection are lymphocytes. They have the ability to accurately recognize an infectious agent, choose the most effective anti -infectious answer and “save” it in immune memory. This makes a repeated answer to the same pathogen even faster and more efficiently. This is the role of B-lymphocytes.

What does it mean-T-lymphocytes, B-lymphocytes in the blood: types where they are produced?

Understanding the phenomenon of immunological memory made it possible to invent one of the most effective methods of protection against infectious diseases - preventive vaccinations. Human lymphocytes are divided into two groups that differ in the maturation process and function. Among them, two types are distinguished:

• T-lymphocytes
• B-lymphocytes

T-lymphocytes, ripening in the thymus (the role of Timus can take on flat epithelia), are the main cells of the so -called cellular immune response. Its mechanisms are mainly associated with the fight against pathogens that can penetrate into human cells (for example, viruses).

B-lymphocytes, On the other hand, they participate in the second type of specific reaction - the so -called humoral immunity. Their task is to produce antibodies that allow you to destroy extracellular pathogens (for example, most bacteria).

The place where B-cells are produced is the bone marrow. Young B-lymphocytes learn to distinguish between their own and foreign structures there. In order for the B cell to leave the bone marrow into the bloodstream, it must be able to detect pathogens, as well as tolerate its own cells of the body. Otherwise, autoimmune diseases may occur, that is, those in which the immune system attacks its own tissues as a result of their recognition as alien.

Having left the bone marrow, B-lymphocytes fall into the peripheral lymphoid organs. These include spleen and lymph nodes. In these areas, B-cells constantly face foreign antigens (“marks” by which they recognize microbes). Recognition of such a marker leads to activation lymphocytes b. Then they begin to multiply, which manifests itself in an increase in the lymph nodes during infection. In order for B-lymphocytes to perform its target function, that is, producing antibodies specific to this pathogen, it must switch to the final stage of maturation.

During the final differentiation B-lymphocyte can be transformed into 2 type of cells:

• Plasmocytes (plasma cell), the task of which is the production of a large number of antibodies (immunoglobulins).
• Memory lymphocyte b, that is, a cell that stores information about this type of pathogen.

In case of repeated contact with this microorganism, memory lymphocyte is quickly transformed into plasma cells, producing antibodies specifically directed against it.

Activity and functions of B-lymphocytes

Now that we know how B-lymphocytes ripen to perform our functions, let's consider their activity in the body in more detail. The most important functions of B-lymphocytes include:

Antigen production:

• B-lymphocytes not only perform their own protective activities (producing antibodies), but also help other cells of the immune system recognize foreign microbes. This function is called the production of antigen (antigen \u003d "label" of microorganism).
• When B-lymphocyte recognizes the “violator”, he attaches its fragment to its surface and shows it to other immune cells, signaling the need to destroy it. Thanks to this, you can activate multidirectional protective mechanisms.

Production of cytokines:

• Cytokines are small protein molecules that carry signals about the invasion of pathogen.
• A sudden increase in the production of cytokines causes "anxiety" for the immune system and leads to the activation of its cells.
• The production of certain types of cytokines allows you to switch the immune response to the one that is most necessary in this situation (for example, antibacterial, antiviral or antiparasitic).

Antibody production:

• The production of antibodies is a unique feature of mature lymphocytes B.
• Antibodies are a type of protein specially adapted to this pathogen to neutralize it.
• An infectious agent (bacteria, virus or extracellular parasite) is no longer dangerous in combination with antibodies.

It also becomes a light target for the cells of the immune system (for example, food cells), which can then recognize and neutralize it.

B-lymphocytes in the blood: production of immunoglobulins

In blood, B-lymphocytes can produce 5th grade immunoglobulins:

1. IgM - These are antibodies formed at the earliest stage of response of B Lymphocytes B. Although they are formed very quickly, they are not very specific. The presence in the blood iGM antibodies Indicates the recent contact of parasites, viruses or bacteria with the body.
2. Iga - This is a type of antibodies playing an important role in places of direct contact with pathogens. IGA immunoglobulins They are secreted on the surface of the mucous membranes of the digestive tract, respiratory tract and genitourinary system.
3. Ige - These are the main antibodies involved in allergic reactions. The presence of antibodies IgE in specific allergens can cause symptoms of allergic rhinitis, conjunctivitis or bronchial asthma when exposed to this allergen. Ige antibodies are also the main antibodies responsible for the fight against parasites.
4. IGD - This is the least known class of antibodies, constantly present on the surface of lymphocytes B.
5. Igg - The most effective antibodies. They arise with the most mature humoral reaction and are best suited for the pathogen in question.

It is worth noting that the concentration of IGG antibodies in the blood can be the highest among immunoglobulins of any other type.

B-lymphocytes in men and women-the norm in the general blood test: decoding

In most standard (general) blood tests, all lymphocytes (b and t) are measured together. Here is the decoding:

• The normal concentration of lymphocytes in men and women - from 1000 to 5000 in 1 μl of blood.
• The percentage of lymphocytes in the entire population of white blood cells is also important. Lymphocytes should be 10-20% All leukocytes.

An increase in the number of lymphocytes - lymphocytosis:

• Accompanies infections and diseases mainly caused by viruses.
• The non -plastic growth of these cells can be less frequent to the excess of lymphocytes.
• Lymphocytosis is also a sign of chronic inflammation (for example, with autoimmune diseases).

A decrease in the number of lymphocytes is called lymphopenia:

• This condition can be caused by various types of immunodeficiency.
• Sometimes a decrease in the number of lymphocytes is caused by taking drugs (or other substances) that worsen the function of the bone marrow and prevent the development of a sufficient amount of these cells.

The reasons for the increase and decrease of lymphocytes in the blood in an adult and child

The reasons for the increase and decrease of lymphocytes in the blood in an adult or child can be different. It is worth noting that there is such a thing as dysfunction B-lymphocytes:

• Among the diseases associated with the abnormal activity of B-lymphocytes, we can distinguish violations of their quantity and function.
• Both deficiency and excess B cells can adversely affect our health.
• In some diseases, B-lymphocytes are present in the desired concentration, but do not function properly. This is, for example, for autoimmune diseases in which B-lymphocytes incorrectly “reject” their own tissues of the body.

Another state - congenital deficiency of humoral immunity:

• These are diseases associated with a decrease in the amount of B-lymphocytes or a significant violation of antibodies.
• Typically, the first symptoms of immunodeficiency appear already in childhood: recurrent and chronic infections that are difficult to treat.

Here are examples of innate humoral immunodeficiencies:

• Bruton's disease is a violation of the maturation of lymphocytes B. It is worth noting that with this pathology there are traces of b-lymphocytes in the blood, and there is practically no antibodies.
• General variable immunodeficiency (ovin), characterized by a decrease in the level of antibodies and the coexistence of non -plastic, allergic and autoimmune diseases.
• Hyper-IGM syndrome caused by the lack of production of non-IGM antibodies. There is a significant deficiency of IGA, Ige and IgG immunoglobulins.

Unfortunately, methods of causal treatment of humoral immunodeficiency have not yet been developed. The main method of therapy is the constant introduction of antibodies from donors (the so -called replacement therapy with immunoglobulin).

Autoimmune diseases It can also be the reason for the increase or decrease in blood lymphocytes:

• One of the key stages of maturation of B-cells in the bone marrow is the so-called negative selection.
• Its essence is to “teach” B-lymphocytes to recognize foreign antigens and eliminate those that recognize their own cells as pathogenic.
• The loss of B-lymphocytes to autoantigens is one of the causes of autoimmune diseases.

Then B-lymphocytes begin to produce the so-called autoantite, that is, antibodies directed against their own cells of the body.

An example of an autoimmune disease associated with the abnormal activity of B cells is the reproduction of B-lymphocytes. B-lymphocytes at any stage of their development can go beyond the natural mechanisms of control of the body and begin uncontrolled reproduction. Neoplastic proliferation of B-lymphocytes can take the following forms:

• Lymphomas - cancer cells primarily affect the lymph nodes
• Leukemia - cancer cells are found in the bone marrow and blood

The most common tumor from B-lymphocytes (at different stages of ripening) is multiple myeloma. This type of cancer lies in the uncontrolled multiplication of plasma cells, which produce a huge number of specific antibodies (the so -called monoclonal antibodies).