Dendritic Cells originate in the bone marrow and function as antigen presenting cells (APCs). In fact, the dendritic cells are more efficient APCs than are macrophages.
These cells are usually found in the structural compartment of such lymphoid organs as the thymus, lymph nodes, and spleen. However, they are also found in the bloodstream and other tissues of the body.
It is believed that they capture antigen or bring it to the lymphoid organs, where an immune response is initiated.
Unfortunately, one reason we know so little about dendritic cells is that they are extremely hard to isolate. Of particular interest is the recent finding that dendritic cells bind high amounts of HIV.
Updated October 2012