Dendritic cells. Computer artwork of dendritic cells, part of the human immune system. These are a type of macrophage cell found in the body's tissues. The long projections seen on the cell's surface help it to move. Dendritic cells recognise and engulf foreign cells. They may then display the foreign antigen as a warning of the infection to other cells. Dendritic cells found in the upper layer of the skin (the epidermis) are known as histiocytes or Langerhans cells. In the central nervous system dendritic cells are known as microglia, and in the liver they are called Kupffer cells.