How do dendritic cells migrate?
Dendritic cells (DCs) travel through lymphatic vessels to transport antigens and present them to T cells in lymph nodes. DCs move directionally toward lymphatics by virtue of their CCR7 and a CCL21 chemotactic gradient.
What is the main function of dendritic cells traveling to where the lymphocytes are located?
Dendritic cells are specialized to take up antigen and display it for recognition by lymphocytes. Immature dendritic cells migrate from the blood to reside in the tissues and are both phagocytic and macropinocytic, ingesting large amounts of the surrounding extracellular fluid.
Do dendritic cells activate lymphocytes?
Identified in mouse spleen for their peculiar shape and capacity to activate naïve lymphocytes (1–3), dendritic cells (DC) are considered the most efficient antigen presenting cells (APC) (3, 4), uniquely able to initiate, coordinate, and regulate adaptive immune responses.
What are migratory dendritic cells?
During embryonic development and postnatally, dendritic cell (DC) progenitors migrate into non-lymphoid organs and differentiate into immature DCs. Immature DCs form a dense network of sentinel cells at all outer and inner surfaces of the body, as well as in most organs.
What cells do dendritic cells interact with?
Dendritic cells (DCs) are antigen-presenting cells (also known as accessory cells) of the mammalian immune system. Their main function is to process antigen material and present it on the cell surface to the T cells of the immune system. They act as messengers between the innate and the adaptive immune systems.
Are dendritic cells in lymph nodes?
The lymph nodes are sites where naive T cells that are in search of their cognate antigen have the opportunity to survey dendritic cells (DCs), the most potent antigen-presenting cells (APCs), for their activation1.
In which organ of human body are lymphocyte cells formed?
thymus
Human lymphoid organs. Lymphocytes develop in the thymus and bone marrow (yellow), which are therefore called central (or primary) lymphoid organs.
What activates dendritic cells?
DCs are activated directly by conserved pathogen molecules and indirectly by inflammatory mediators produced by other cell types that recognise such molecules. In addition, it is likely that DCs are activated by poorly characterised cellular stress molecules and by disturbances in the internal milieu.
Do dendritic cells travel in the blood?
They are also present in lymphoid tissues, including the lymph nodes and spleen. To migrate to these locations, DCs travel via the blood or in lymph vessels.
How does the homing of lymphocytes work?
Lymphocyte subsets express unique patterns of homing molecules and the various types of vascular endothelium in different tissues express specific ligands, enabling migrating lymphocytes to be guided to their target tissue via site-specific pathways.
How does DC work in the lymph node?
In addition to constitutive trafficking of DC to the draining lymph node in the presence of danger signals such as pathogens or cytokines, DC upregulate molecules such as CCR7 and move to the draining lymph node. Here DC present antigens to naïve T cells and are unique among antigen-presenting cells in their ability to do this.
How are T cells homing to peripheral tissues?
Naïve T cells express homing receptors that allow them to migrate to lymphoid organs like lymph nodes, but they are usually excluded from peripheral tissues. Once T cells have become activated by antigen, they change their pattern of homing receptors and can migrate to peripheral sites.
Are there any homing molecules in the skin?
These effector T cells trafficking to the skin are devoid of the gut homing molecules α4β7 and CCR9. Conversely, gut tropic cells do not have skin-homing molecules.