Figure 6: A20 tumor cells as tolerogenic antigen-presenting cells were differentiated into functional phenotypes after treatment of rR9-GRIM19 in culture. (A): Expression of I-Ad, CD80, CD86, and PD-L1 in A20 cells after rR9-GRIM19 treatment in culture. A20 cells were pre-cultured in cultured medium containing one or no rR9-fusion protein for 24 h. Untreated or rR9-fusion protein-treated A20 cells were stained with mAbs. Gray lines, isotype control IgG; thin lines, untreated A20 with mAbs; thick lines, rR9-GFP-treated A20 with mAbs; double-thick lines, rR9-GRIM19-treated A20 with mAbs. Data are representative of three individual experiments. (B): Co-cultivation study of CD8+ or CD4+ T cells with rR9-fusion protein-pretreated A20 cells. Purified CD8+ or CD4+ T cells from naïve mice were co-cultured with untreated A20 cells or A20 cells that had been pre-treated for 24 h with rR9-GFP or rR9-GRIM19; all co-cultures were maintained in the presence of exogenous rIL-2 for 5 days in vitro. Cells were then stained with mAbs. FACS analyses were performed. Data are representative of two individual experiments. (*; p < 0.05, **; p < 0.01)