DENDRITIC CELLS

cells which circulate in the bloodstream and identify antigens in order to activate the specific killer T cells for that antigen (Immunology)

Dendritic cells (DCs) are immune cells and form part of the mammalian immune system. Their main function is to process antigen material and present it on the surface to other cells of the immune system, thus functioning as antigen-presenting cells.Dendritic cells are present in small quantities in tissues that are in contact with the external environment, mainly the skin (where they are often called Langerhans cells) and the inner lining of the nose, lungs, stomach and intestines. They can also be found in an immature state in the blood. Once activated, they migrate to the lymphoid tissues where they interact with T cells and B cells to initiate and shape the adaptive immune response. At certain development stages they grow branched projections, the dendrites, that give the cell its name. However, these do not have any special relation with neurons, which also possess similar appendages. Immature dendritic cells are also called veiled cells, in which case they possess large cytoplasmic 'veils' rather than dendrites.
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the most immune-stimulating cells in the human body, occurring naturally in tissues that contact the exterior environment: in the skin and the lining of nose, lungs, stomach, and intestines; they get their name from their long tentacle-like arms, called dendrites, and form from circulating monocytes; they function as antigen-presenting cells and attract invading viruses and bacteria, then cut those proteins into short, linear peptide pieces (see epitope), and carry the fragments on their surfaces (enmeshed in their tentacles) through the blood stream to lymph nodes to activate B cells, helper T cells, and CTLs; only dendritic cells can activate a helper T cell that has never before encountered a particular antigen before. (see: epitope)