<unk> s <unk> s) 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.<unk> s 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<unk> s are also called veiled cells, in which case they possess large cytoplasmic 'veils' rather than dendrites.
Dendritic cell
T cell
Reactive lymphocyte
Monocyte
Histiocyte
Plasma cell
B cell
Lymphocyte