FIGURE 1.

Loss of CCL19 expression in dendritic cells blocks T cells from forming conjugates with dendritic cells in vitro. A, bone marrow-derived dendritic cells (DC) generated from C57BL/6 mice, stained with an isotype control or CD11c antibodies were analyzed by flow cytometry. B, DC that lack CCL19 expression fails to form conjugates with OTI T cells. DC were transfected with control, 234 (CCL19), or 452(CCL19) shRNA, and 72 h later loaded with ovalbumin during maturation. Cells were incubated with OTI T cells for 2 h. Cell were rinsed, fixed in paraformaldehyde, and the number of conjugates formed per 100 cells counted. Error bars are mean ± S.E. *, p = 0.0313 for 234, and **, p = 0125 for 452 Student's t test versus control. C, representative image of CMTMR-labeled OVA loaded, TNF-α matured DCs forming conjugates with CSFE-labeled OTI T cells. D, RT-PCR of 5 μg of mRNA isolated from DC transfected with control, or 452(CCL19) shRNA plasmids. Data are representative of three independent experiments.