The principle cells of the immune system consist of different types of cells that have diverse functions, which boost the immune system through antigens recognition, capturing, and elimination. The main types of cells in the immune system are lymphocytes, effector cells, and antigen-presenting cells (Grossman, 2014). The lymphocytes consist of natural killer cells, T lymphocyte, and B lymphocyte. The antigen-presenting cells exist in three forms, which are macrophages, follicular-dendritic, and dendritic cells. Lastly, the effector cells exist in the form of granulocytes, T lymphocyte, and macrophage (Grossman, 2014). Despite existing in different forms, the principle cells of the immune system have unique functions that range from detection, incarceration, and eventual elimination of the antigens to ensure that the immune system is functioning at optimal (Townsend, 2012).
Role of the Principle Cells of the Immune System in the Immune Response
The lymphocyte cells are critical in the antigens recognition within the immune system in order to trigger appropriate response. Specifically, the B lymphocyte which is part of the lymphocyte cells performs the role of a mediator medium the humoral protection. On the other hand, the T lymphocyte performs the role of a mediator medium of cell-mediated protection. Lastly, the natural killer cells perform the role of a mediator medium of innate immunity (Grossman, 2014). Whenever the lymphocytes “encounter an antigen for which they are specific in one of the peripheral lymphoid tissues, they will become activated and initiate an adaptive response” (Townsend, 2012, p. 656). Basically, the lymphocyte cells are proactive in adaptive protection within the immune system. Mature lymphocyte cells migrate from the lymphoid organs and continuously flow “through the peripheral sites of the body looking for antigens to recognize and respond to” (Townsend, 2012, p. 656).
As part of the principle cells within the immune system, the antigen-presenting cells perform the role of capturing of the antigens with the aim of displaying them to the lymphocytes (Grossman, 2014). The antigen-presenting cell “has receptors that recognize broad classes of microbial antigens. When stimulated, these receptors cause the stimulating antigen to be endocytosed” (Townsend, 2012, p. 657). For instance, the dendretic cells perform the role of initiating the responses of the T cell. Moreover, the macrophages perform the role initiating the “effector phase of cell-mediated immunity” (Townsend, 2012, p. 656). Lastly, the follicular-dendritic cells perform the role of displaying the captured antigens to “B lymphocytes in humoral immune responses” (Townsend, 2012, p. 656).
The effector cells perform the last duty of the principles cells of the immune system, which is eradication of the displayed antigens that have been captured by the antigen-presenting cells. The role of eliminating the antigens occurs in several ways. For instance, the monocytes eliminate the “cells of the mononuclear phagocyte system” (Townsend, 2012, p. 656). On the other hand, the T lymphocytes perform the role of helping the T cells and cytolytic T lymphocytes in antigen eradication. Generally, the effector cells “stimulate macrophages to kill endocytosed microbes, activate cytotoxic T cells and NK cells which directly kill infected cells, activate plasma cells (antibody-secreting B cells) which secrete antibodies that target antigens for destruction” (Townsend, 2012, p. 657). The immune system response is completed when the antigens are destroyed through the three-phased process which begins from recognition to capturing, and ends with the elimination of the antigens.
Grossman, S. (2014). Porth’s Pathophysiology. New York, NY: Lippincott Williams & Wilkins
Townsend, C. (2012). Sabiston textbook of surgery: The biological basis of modern surgical practice. New York, NY: Elsevier Science Health Science Division.