The Autographa californica nuclear polyhedrosis virus AcNPV induces functional maturation of human monocyte-derived dendritic cells.

The initiation of an adaptive immune response is critically dependent on the activation of dendritic cells (DCs). Therefore, vaccination strategies targeting DCs have to ensure a proper presentation of the immunogen as well as an activation of DCs to accomplish their full maturation. Viral vectors can achieve gene delivery and a subsequent presentation of the expressed immunogen, however, the immunization efficiency may be hampered by an inhibition of DC activation. Here we report that the insect born Autographa californica nuclear polyhedrosis virus (AcNPV), which is already used for genetic immunization, is able to activate human monocyte-derived DCs. This activation induces the production of tumor necrosis factor alpha (TNF-alpha), an up-regulation of the surface molecules CD83, CD80, CD86, HLA-DR and HLA-I and increases the T cell stimulatory capacity of DCs. Thus, AcNPV represents a promising vector for vaccine trials.