Influence of particle size, an elongated particle geometry, and adjuvants on dendritic cell activation

Modern subunit vaccines have many benefits compared to live vaccines such as convenient and competitive large scale production, better reproducibility and safety. However, the poor immunogenicity of subunit vaccines usually requires the addition of potent adjuvants or drug delivery vehicles. Accordingly, researchers are investigating different adjuvants and particulate vaccine delivery vehicles to boost the immunogenicity of subunit vaccines. Despite the rapidly growing knowledge in this field, a comparison of different adjuvants is sparsely found. Until today, little is known about efficient combinations of the different adjuvants and particulate vaccine delivery vehicles. In this study we compared three adjuvants with respect to their immune stimulatory potential and combined them with different particulate vaccine delivery vehicles. For this reason, we investigated two types of polyI:C and a CL264 base analogue and combined these adjuvants with differently sized and shaped particulate vaccine delivery vehicles. A high molecular weight polyI:C combined with a spherical nano-sized particulate vaccine delivery vehicle promoted the strongest dendritic cells activation.