Monocytopoiesis

Monocytosis can also occur in various pathological processes.

Monocytes of monocytic origin arise from myeloid tissue of the bone marrow through a complex process of their formation and differentiation, which is called monocyte- and macrophagopoiesis. As a result of this process, monocytes, granulocytes and megakaryocytes are formed. There are two phases of monocytogonic hematopoiesis: the first is long-term, during which immature monoblasts enter the peripheral blood and subsequently form monocytes by differentiation from monoblasts (by expressing monocyte markers), for example SLA-DR, A-SAB 78, SCF 44/HIF 3a, MPO, TER 119, GPA-2 under the influence of G-CSF, GM-CSF.

The second phase is represented by the formation of mature monocytes from precursors through apoptosis (due to the expression of tumor necrosis factor receptors (TNF-R)). After leaving the bone marrow into the blood, monocytes migrate to tissues, where they carry out phagocytosis. Once removed from tissue, monocytes recirculate into the bone marrow, ending up in specialized areas of the bone marrow - the “normal” “monocyte reserve”. Monocytes that have left the circulation undergo reverse development (the process of dedifferentiation) and donate the nucleus to macrophages, turning into macrophage elements. Thus, the monocytic hematopoietic process is strictly individual for each individual person with its duration, intensity, and frequency.

Monocytopoiesis is the process of formation and development of monocytes, which are a type of white blood cell. They play an important role in the body's immune system, providing protection against infections and other health threats.

Monocytes are produced in the bone marrow and then migrate into the blood, where they circulate for up to several weeks before differentiating into many different types of immune cells, such as macrophages, dendritic cells, mononuclear phagocytes, and B lymphocytes.

The role of monocytes in the immune system is due to their ability to phagocytose and produce cytokines such as interferon-gamma and tumor necrosis factor-alpha. These proteins promote the activation and recruitment of additional immune system cells, thereby enhancing the immune response.

One of the most important functions of monocytes is participation in the process of inflammation. When an infection occurs, the body's defense mechanisms are mobilized, causing a cascade of reactions that leads to the development of inflammatory reactions. Monocytes migrate to the inflamed area and begin to phagocytose pathogenic microorganisms and their metabolic products. This helps reduce infection activity and stop inflammatory reactions.

In addition, monocytes may participate in the regulation of immune tolerance and suppression of transplant rejection by migrating to the transplantation site and suppressing immune responses.