Epithelial Reticular Cells of the Thymus
Epithelial reticular cells of the thymus can also be called epitheliocytes or thymic nurse cells. They take an active part in the maturation of lymphocytes and guarantee their active role in cell-mediated immunity (Thymus development, 2019). Considering their embryological aspect, it can be stated that they evolve from the endodermal cells of the third pharyngeal pouch; it is evidenced by the existence of basement membrane in the structure and desmosomes (Thymus development, 2019). Also being a part of the blood thymic barrier, the given type of cells is important for the preservation of the main blood’s functions preventing the antigens from reaching the T-lymphocytes (Thymus development, 2019).
Regarding the existing differences in their structure, investigators distinguish five main types of epithelial reticular cells of the thymus.
- Type I – form the blood-thymic barrier and can be found in the inner aspect of the capsule.
- Type II, III – are observed outside the cortex and some of its parts.
- Type IV – usually are present in the inner and deeper parts of the cortex
- Type V – these are cells that are placed around Hassell’s corpuscles. Their main function is to eliminate T cells that react with self-antigens (Thymus development, 2019).
Lymphocytopenia
Lymphocytopenia, or lymphopenia, can be determined as the emergence of particular problems in the structure of blood as lymphocyte count is lower than the norm (Lymphocytopenia, n.d.). This state indicates the high risk of infection or other diseases that deteriorate the state of a person as lymphocytes are a type of white blood cells responsible for the appropriate functioning of the immune system. They might precondition the initiation of needed immune responses to struggle against the pathogen (Lymphocytopenia, n.d). There are three major types of lymphocytopenia regarding types of these blood cells:
T-lymphocytopenia occurs when there is a too low number of T-lymphocytes in the blood and their deficiency emerges (Lymphocytopenia, n.d).
B-lymphocytopenia is observed when there are few B lymphocytes while other types of these blood cells are present
NK lymphocytopenia is diagnosed when there is an insufficient amount of natural killer cells (Lymphocytopenia, n.d).
References
HxBenefit Editorial Team. (2018). Low lymphocytes. Web.
Lymphocytopenia. (n.d.). Web.
Thymus development. (2019). Web.