Presentation of anti-hOSCAR mAb to a T-cell clone specific for mouse IgG1 by mono-DCs. The primary antibodies MOPC21 (▪; isotype control), anti-CD13 (▴), anti-hOSCAR (○), or anti–mannose receptor (•) were allowed to bind to mono-DCs. After cross-linking with GAM F(ab′)₂, the irradiated mono-DCs were added to a T-cell clone specific for mouse IgG1. Antigen presentation was assessed by [³H]-thymidine incorporation corresponding to T-cell proliferation. Anti–mannose receptor and anti-hOSCAR were presented more efficiently than anti-CD13 mAbs or isotype control. Data shown are representative of 4 independent experiments using cells from 3 different donors and display the mean and standard deviation of quadruplets. Statistical significances of *P < .03; **P < .01 are given by comparison to values obtained with the negative control anti-CD13.