In vitro assay for screening of optimal targets for antigen-delivery to murine dendritic cells

Targeting of antigen to dendritic cells (DCs) have been shown to increase the efficiency of immunization procedures and may facilitate the development of more effective vaccines. Several surface molecules on DCs have shown to be useful for antigen targeting, but many more deserves investigation for their efficacy in this respect. With this end in mind, a simple in vitro assay for screening of optimal targets for antigen-delivery to murine DCs was established. Splenocytes from mice immunized with rat IgG were targeted in vitro with a panel of different rat monoclonal antibodies (mAbs) directed against surface markers in murine DCs. The resulting T cell activation was analyzed by determining the number of IFN-γ and IL-4 secreting cells by ELISPOT. A positive effect of targeting was evident with several of the mAbs. Thus, Abs against CD11c, CD36, CD205 and Clec7A all induced IFN-γ responses that were significantly higher than those induced by non-targeting control mAbs. Anti-CD36 also induced IL-4 responses that were significantly higher than the control. The assay described here allows simultaneous analysis of a large number of potential target structures and facilitates direct comparison between the different targets reGemgarding the strength of the T cell responses induced by the targeted DCs. The assay could be useful as a first-line screening of potential target structures on murine DCs. This article is protected by copyright. All rights reserved.