AP-1–dependent Gal1 expression in EBV-transformed LCLs and primary PTLDs. (A) Total phospho-cJun and JunB expression in the cHL cell line L428 and in 2 EBV-transformed LCLs, RIC and NOR. β-Actin was used as a loading control. (B) ChIP-PCR analysis of cJun and JunB binding to LGALS1-enhancer regions in the cHL cell line L428 and in 2 LCLs, NOR and RIC. Results are representative of triplicate experiments. (C) Densitometric analyses of ChIP-PCR data from panel B. (D) LGALS1-promoter- and enhancer-driven luciferase activity in LCLs. NOR cells were cotransfected with 300 ng of the pGL3-Gal1–promoter constructs (without or with the wild-type or mutant AP-1–dependent LGALS1 enhancer) and 100 ng of the control reporter plasmid pRL-TK, and evaluated for relative luciferase activity, as described previously.4 (E) Immunohistochemistry analysis of JunB (i,iii,v) and phospho-cJun (ii,iv,vi) in 3 primary EBV+ PTLDs. The PTLDs had uniformly high nuclear staining of JunB and positive phospho-cJun staining of variable intensity.
