Figure 2. FR104 treatment prolongs human skin allograft survival.

(A) Schematic representation of the chimeric humanized mouse model. BALB/c Rag2^–/–cγ^–/– mice were transplanted with a human skin graft, which was allowed to heal for 35 days before adoptive transfer of 10 × 10⁶ PBMCs i.p. After confirmation of adequate PBMC engraftment on day 21 after adoptive transfer, groups of mice were treated with saline (n = 5), PEG (n = 3), FR104 (n = 5), or CTLA4-Ig (n = 5) i.v. (B) Only FR104 treatment prolonged skin graft survival. (FR104 1 mg/kg vs. saline, P = 0.0116; and FR104 5 mg/kg vs. saline, P = 0.0031; log-rank test). (C) Chimerism levels of human CD45⁺ cells in the peripheral blood on day 21 and day 28 after adoptive transfer.