FIG 2 .
In vivo antigen delivery to dendritic cells by MHV-based vaccine vectors. B6 mice were immunized i.v. with 106 PFU MHV-GP or MHV-GM/GP or were left untreated. Spleens were collected after 18 h, 24 h, or 36 h and digested with collagenase, and low-density cells were isolated by gradient centrifugation. Expression of CD11c, CD11b, CD8α, CD86, and CD40 on DCs was determined by flow cytometry. (A) Time course analysis of EGFP expression in CD11c+ DCs. Pooled data from two separate experiments (5 mice per time point). Values in the upper right quadrant indicate mean percentages plus SEM of EGFP+ cells. (B) Expression of CD11b and CD8α in transduced DCs at 18 h postinfection. Values in the quadrants represent percentages of CD11b+ or CD8α+ cells in the EGFP+ CD11c+ DCs. (C) DC activation assessed as CD86 and CD40 upregulation on EGFP+ CD11c+ and EGFP− CD11c+ cells at the 18-h time point. Values in the histograms represent mean fluorescence intensity of the respective population. PBS, phosphate-buffered saline.