Serum antidonor Ab titers in passively transferred recipients. In vivo experiment: sera collected between 4 weeks to 6 weeks after skin grafting were pooled from B10 mice sensitized by B10.BR skin grafts, and 10 to 500 μL was injected intravenously into naive B10 mice (n = 4 mice/group). Sera were collected 1 day after serum infusion. In vitro experiment: pooled sensitized sera were serially diluted (1:1-1:1000). Each dilution had 3 samples. FCXM assays were performed for in vivo and in vitro experiments. Donor B10.BR splenocytes (0.5 × 106) were incubated with 5 μL serum and then incubated with FITC-conjugated goat anti-mouse immunoglobulin, followed by incubation with PE-conjugated anti-mouse CD4 plus CD8. Levels of antidonor Ab were determined by FACSCalibur and reported as MFI. Error bars indicate SD.
