Definition of Dendritic cells

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)

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Patrolling immune system cells that may begin the HIV disease process by carrying the virus from the site of the infection to the lymph nodes<!-- (see) -->, where other immune cells become infected. Dendritic cells travel through the body and bind to foreign invaders -- such as HIV -- especially in external tissues, such as the skin and the membranes of the gut, lungs, and reproductive tract. They then ferry the foreign substance to the lymph nodes to stimulate T cells<!-- (see) --> and initiate an immune response. In laboratory experiments, the dendritic cells that carry HIV also bind to CD4+ T cells<!-- (see) -->, thereby allowing HIV to infect the CD4+ T cells. CD4+ T cells are the primary immune system cells targeted by HIV and depleted during HIV infection.