Myeloid and plasmacytoid dendritic cells, a family of professional antigen presenting cells, are crucial in generating and maintaining anti-viral immunity. Many viruses have evolved to avoid, subvert, and even counterattack them. In this article, we focus on the tuning of innate and adaptive responses induced by human dendritic cells, and on the inhibition of their functions by viruses of medical significance. A constant "tug of war" goes on between dendritic cells and viruses and a main dendritic cell countermeasure is cross-presentation/priming.