The dendritic cell as a special leukocyte
As a rule, dendritic cells exist as antigen-presenting particles in the human organism. As a special form of white blood cells, they have special molecules on their surface that serve to activate T cells.
The job of these cells is to generate and present antigens . If there is a foreign body in the immune system, the intracellular structures identify it. The foreign pathogens are, for example, bacteria, fungi or micro-organisms.
The definition of the dendritic cell
Dendritic cells are located within the immune system. This type of particle is divided into different types. These arise from monocytes . The development from B and T progenitor cells also represents a possible origin. Accordingly, these particles are connected by a distant cell relationship. They owe their name “dendritic cells” to their function.
Dendritic cells are among the only cell types that elicit an immediate immune response . They do this by activating naive T cells.
According to recent research, these cells do not work exclusively with T cells. They also interact with the other two types of lymphocytes. These appear in the form of natural killer cells and B cells. Accordingly, dendritic cells are among the professional, antigen-presenting cells within the immune system. Others of this type are:
- monocytes ,
- macrophages
- and B lymphocytes.
The appearance and maturation of these cells
An immature dendritic cell has a star-shaped exterior . The processes on it consist of cytoplasm and are called dendrites. The mature cell is subject to constant movement with its processes. This allows them to scavenge antibodies from the plasma. As the cell ages, the dendrites give way to veil-like membrane folds. They used to be called veil cells.
The classification of this cell type
The dendritic cells differ based on their appearance and the features on their surface. Specialists call these characteristics clusters of differentiation. The two forms of these cells are myeloid and plasmacytoid dendritic cells. The myeloids are similar to the monocytes. The plasmacytoids look like plasma cells .
These cells are further divided into cell types. These include the follicular dendritic reticulum cells, the Langhans cells and the inter-digitating dendritic reticulum cells. The latter exist predominantly in the lymphatic tissue. In contrast, the Langhans cells are located in the epidermis called epidermis.
The exact function of these cells
The dendritic cells in the immune system assume their function. Here they ensure the constant monitoring of the tissue. Extracellular particles engulf the dendritic cell by phagocytosis or endocytosis. They then identify the foreign bodies and report them to the immune system.
The components of the antigens come to the surface of the cell as peptides. It is irrelevant whether the foreign bodies appear as proteins or microorganisms. When the dendritic cell comes into contact with an antigen, it leaves the tissue. It migrates to a new lymph node. Here it joins forces with a T cell and induces a specific immune response.
Furthermore, the dendritic cell avoids autoimmune reactions. In return, it ensures an immunological tolerance that refers to the self-antigens. Their task is to recognize the body’s own cell parts. If there is no infection in the organism, the dendritic cell stimulates the T cells. This leads to apoptosis, anergy or the development of regulatory T cells. Self-reactive T cells remove these cell types from peripheral lymphocytes.
The dendritic cell and the leukocytes
Dendritic cells belong to the leukocytes . The white blood cells deal with the fight against incompatible substances. In addition to viruses and toxins, tumor cells and protozoa are also possible pathogens. The leukocytes are divided into different genera. The dendritic cell is one of the cell types capable of phagocytosis . As a phagocyte, it absorbs the foreign material.
The dendritic cell is a specific type of white blood cell. This cell type is classified into different shapes depending on the appearance and features on the cell surface. The absorption and destruction of foreign bodies in the body is one of the tasks of these cells.
