Skip to main content
. Author manuscript; available in PMC: 2009 Apr 8.
Published in final edited form as: J Immunol. 2007 Sep 1;179(5):2999–3011. doi: 10.4049/jimmunol.179.5.2999

FIGURE 6.

FIGURE 6

NF-κB binding sequence in intron 2 modulates the promoter activity of the FcRn gene. A, Designations and diagrams of the luciferase reporter constructs. The reporter construct (P1) contains the FcRn promoter sequence from −1801 to +863 kb. The P2 construct represents the FcRn promoter sequence, exon 1, exon 2, and partial exon 3. Asterisks represent the start codon ATG mutation (Mut) in FcRn. Arrows denote the two putative initiation sites for transcription (17). The mutated nucleotides in the P3 construct are underlined. Exons (E) are drawn as boxes and introns are shown as roman numerals. LUC, Luciferase. B, Effects of NF-κB binding sequence (+1104) in intron 2 in regulating the FcRn promoter in untreated THP-1 cells. THP-1 cells were transiently transfected with the indicated vector alone or the luciferase reporter constructs P1, P2, and P3, respectively. After 24 h the cells were harvested and protein extracts were prepared for the luciferase assays. Results are expressed as relative luciferase activity and represent the mean value from at least three experiments. C, Effects of NF-κB site (+1104) in intron 2 in moderating FcRn promoter activity in the presence of NF-κB or the IκBα dominant negative (S32A/S36A). THP-1 cells were transiently transfected with the P2 construct together with the plasmids as indicated. Luciferase activity was measured 24 h posttransfection. Transcriptional activity was measured as firefly luciferase activity and normalized to Renilla luciferase activity as described above. The results show the mean of three independent experiments. pBUD, pBudCE4 vector. D, Effects of NF-κB site (+1104) in intron 2 in moderating FcRn promoter activity in TNF-α -treated cells. THP-1 cells were transiently transfected with the P2 luciferase reporter constructs. Twenty-four hours after transfection, cells were either mock treated (solid bar) or treated with TNF-α (gray bar). After 12 h of stimulation the cells were harvested and protein extracts were prepared for the luciferase assay as described above. The results show the mean value from three independent experiments.