Dendritic cell: Difference between revisions

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[[Image:Dendritic cell.JPG|thumb|right|230px|A dendritic cell]]
{{Short description|Type of immune cell}}
{{DISPLAYTITLE:Dendritic cell}}


'''Dendritic cells''' (DCs) are [[white blood cells]] forming part of the [[mammal]]ian [[immune system]]. They process [[antigen]] material from [[pathogen]]s and put it on their surface. There it touches other cells of the immune system.  So, dendritic cells are antigen-presenting cells. They act as [[wikt:messenger|messengers]] between the [[Innate immune system|innate]] and [[adaptive immune system]]s.
==Overview==
[[Dendritic cells]] (DCs) are a type of [[antigen-presenting cell]] (APC) that play a crucial role in the [[immune system]]. They are responsible for processing [[antigen]] material and presenting it on their surface to other cells of the [[immune system]], thus acting as messengers between the [[innate immune system|innate]] and [[adaptive immune system|adaptive]] immune systems.


Dendritic cells are present in [[Tissue (biological)|tissues]] in contact with the external environment. These tissues are the [[skin]], and the inner lining of the [[nose]], [[lungs]], [[stomach]] and [[intestine]]s. They can also be found in an immature state in the [[blood]].
==Structure and Function==
Dendritic cells are characterized by their branched projections, which give them a tree-like appearance. These projections increase the surface area available for contact with other cells, enhancing their ability to capture and present antigens. DCs are found in tissues that are in contact with the external environment, such as the skin (where they are known as [[Langerhans cells]]), and the inner lining of the nose, lungs, stomach, and intestines.


== Young dentritics ==
===Antigen Capture and Presentation===
Dedritic cells develop from [[monocyte]]s, white blood cells which circulate in the body. Depending on the signal, monocytes turn into either dendritic cells or [[macrophage]]s. The monocytes are formed from [[stem cell]]s in the [[bone marrow]].
Dendritic cells capture antigens through various mechanisms, including [[phagocytosis]], [[endocytosis]], and [[pinocytosis]]. Once an antigen is captured, it is processed into smaller fragments and presented on the cell surface bound to [[major histocompatibility complex]] (MHC) molecules. This presentation is crucial for the activation of [[T cells]], which are essential for the adaptive immune response.


Immature dendritic cells constantly sample their surrounds for pathogens such as [[virus (biology)|viruses]] and [[bacteria]]. This is done through [[pattern recognition receptors]] (PRRs) such as the [[toll-like receptor]]s (TLRs).
===Migration and Maturation===
Upon capturing antigens, dendritic cells undergo a maturation process and migrate to the [[lymph nodes]]. During this migration, they undergo changes that enhance their ability to activate T cells. In the lymph nodes, mature dendritic cells present the processed antigens to [[naive T cells]], leading to their activation and differentiation into [[effector T cells]].


They [[phagocytosis|eat]] pathogens and break down their [[protein]]s into small pieces and put these fragments on their cell surface using [[major histocompatibility complex|MHC]] molecules. Once activated, these cells move to the [[lymph node]]s and become mature.<ref>At a particular stage, these cells grow branches called ''dendrites''. The name comes from the Greek word ''δένδρον'', or ''déndron'' that means "tree". Immature dendritic cells are also called '''veiled cells''', as they have large cytoplasmic 'veils', not dendrites.
==Types of Dendritic Cells==
</ref> They switch on cell-surface receptors which activate [[T cell]]s and [[B cell]]s to start and shape the [[Adaptive immune system|adaptive immune response]].
Dendritic cells can be classified into several types based on their origin and function:


==History==
* '''Conventional Dendritic Cells (cDCs):''' These are the most common type and are primarily involved in antigen presentation and T cell activation.
Dendritic cells were first described by [[Paul Langerhans]] (Langerhans cells) in the late nineteenth century. It wasn't until 1973, however, that [[Ralph Steinman]] and Zanvil  Cohn gave them the name 'dendritic cells'.<ref name=Steinman>{{cite journal |author=Steinman R.M. & Cohn Z.A. |title=Identification of a novel cell type in peripheral lymphoid organs of mice. I. Morphology, quantitation, tissue distribution |journal=J. Exp. Med. |volume=137 |issue=5 |pages=1142–62 |year=1973 |pmid=4573839|doi=10.1084/jem.137.5.1142 |pmc=2139237}}</ref> For discovering the central role of dendritic cells in the adaptive immune response,<ref name="pmid9521319">{{cite journal |author=Banchereau J. & Steinman R.M. |title=Dendritic cells and the control of immunity |journal=Nature |volume=392 |issue=6673 |pages=245–52 |year=1998 |pmid=9521319 |doi=10.1038/32588 |url=}}</ref> Steinman was awarded the [[Albert Lasker Award]] in 2007,<ref name="Lasker2007">{{cite web |url=http://www.laskerfoundation.org/awards/2007basic.htm |title=The Lasker Foundation - 2007 Awards |work= |accessdate=2010-11-27}}</ref> and the [[Nobel Prize in Physiology or Medicine]] in 2011.<ref name="Nobel2011">{{cite web |url=http://www.nobelprize.org/nobel_prizes/medicine/laureates/2011/# |title=Nobel Prize in Physiology or Medicine for 2011"}}</ref>
* '''Plasmacytoid Dendritic Cells (pDCs):''' These cells are known for their ability to produce large amounts of [[interferon]] in response to viral infections.
* '''Langerhans Cells:''' A specialized type of dendritic cell found in the skin.
* '''Monocyte-derived Dendritic Cells:''' These cells arise from [[monocytes]] and are often generated in response to inflammation.


== References ==
==Role in Immune Response==
{{Reflist}}
Dendritic cells are pivotal in initiating and regulating the immune response. By presenting antigens to T cells, they help determine the nature of the immune response, whether it be [[cell-mediated immunity]] or [[humoral immunity]]. They also play a role in maintaining [[immune tolerance]] by presenting self-antigens to T cells in a way that prevents an autoimmune response.


==Clinical Significance==
Dendritic cells are being studied for their potential in [[immunotherapy]], particularly in the treatment of [[cancer]] and [[autoimmune diseases]]. By manipulating dendritic cells to present specific antigens, researchers aim to enhance the body's immune response against tumors or modulate it to reduce autoimmune reactions.


[[Category:Blood cells]]
==Related Pages==
[[Category:Immunology]]
* [[Antigen-presenting cell]]
* [[Immune system]]
* [[T cell]]
* [[Langerhans cell]]
 
[[Category:Immune system]]
[[Category:Cell biology]]

Latest revision as of 19:04, 22 March 2025

Type of immune cell



Overview[edit]

Dendritic cells (DCs) are a type of antigen-presenting cell (APC) that play a crucial role in the immune system. They are responsible for processing antigen material and presenting it on their surface to other cells of the immune system, thus acting as messengers between the innate and adaptive immune systems.

Structure and Function[edit]

Dendritic cells are characterized by their branched projections, which give them a tree-like appearance. These projections increase the surface area available for contact with other cells, enhancing their ability to capture and present antigens. DCs are found in tissues that are in contact with the external environment, such as the skin (where they are known as Langerhans cells), and the inner lining of the nose, lungs, stomach, and intestines.

Antigen Capture and Presentation[edit]

Dendritic cells capture antigens through various mechanisms, including phagocytosis, endocytosis, and pinocytosis. Once an antigen is captured, it is processed into smaller fragments and presented on the cell surface bound to major histocompatibility complex (MHC) molecules. This presentation is crucial for the activation of T cells, which are essential for the adaptive immune response.

Migration and Maturation[edit]

Upon capturing antigens, dendritic cells undergo a maturation process and migrate to the lymph nodes. During this migration, they undergo changes that enhance their ability to activate T cells. In the lymph nodes, mature dendritic cells present the processed antigens to naive T cells, leading to their activation and differentiation into effector T cells.

Types of Dendritic Cells[edit]

Dendritic cells can be classified into several types based on their origin and function:

  • Conventional Dendritic Cells (cDCs): These are the most common type and are primarily involved in antigen presentation and T cell activation.
  • Plasmacytoid Dendritic Cells (pDCs): These cells are known for their ability to produce large amounts of interferon in response to viral infections.
  • Langerhans Cells: A specialized type of dendritic cell found in the skin.
  • Monocyte-derived Dendritic Cells: These cells arise from monocytes and are often generated in response to inflammation.

Role in Immune Response[edit]

Dendritic cells are pivotal in initiating and regulating the immune response. By presenting antigens to T cells, they help determine the nature of the immune response, whether it be cell-mediated immunity or humoral immunity. They also play a role in maintaining immune tolerance by presenting self-antigens to T cells in a way that prevents an autoimmune response.

Clinical Significance[edit]

Dendritic cells are being studied for their potential in immunotherapy, particularly in the treatment of cancer and autoimmune diseases. By manipulating dendritic cells to present specific antigens, researchers aim to enhance the body's immune response against tumors or modulate it to reduce autoimmune reactions.

Related Pages[edit]