Dengue virus infection. Animation of a dengue virus particles (green) and dendritic cells (cream) in the lymphatic system. Dendritic cells are a component of the body's immune system. Dendritic cells are antigen-presenting cells (APCs), that is, they present pathogens or foreign molecules (antigens) to other cells of the immune system to be eliminated. Dengue virus, transmitted by the bite of Aedes sp. mosquitoes, causes the tropical disease dengue fever in humans. Symptoms can range from a mild fever and joint pain to spontaneous bleeding of the skin and circulatory failure, which are often fatal.