Effects of LPS and sCD26/DPPIV(+) or sCD26/DPPIV(−) stimulation of THP-1 cells and monocytes on the binding affinity of transcription factors with the human TNF-α and IL-6 gene promoters, assessed by ChIP assay.

<p>A, C. Effects of stimulating THP-1 cells with a combination of LPS and sCD26/DPPIV(+) or sCD26/DPPIV(−) on the binding affinity of transcription factors to the human TNF-α and IL-6 gene promoters. THP-1 cells (5×10⁵) were incubated in culture medium with or without LPS, with or without various concentrations of sCD26/DPPIV(+) or sCD26/DPPIV(−), and with or without the DPPIV inhibitor P32/98 (10 µM). The cells were then cultured for the indicated periods. They were fixed and subjected to ChIP analysis. Each panel shows a typical example of the results. Values represent mean ± S.E.M., n = 3, *<i>P</i><0.05 vs. control. **<i>P</i><0.05 vs. stimulation by LPS alone. ^#<i>P</i><0.05 vs. sCD26/DPPIV(+). B, D. Effects of stimulating monocytes with a combination of LPS and sCD26/DPPIV(+) or sCD26/DPPIV(−) on the binding affinity of transcription factors to the human TNF-α and IL-6 gene promoters. Monocytes (5×10⁵) were incubated in culture medium with or without LPS, with or without various concentrations of sCD26/DPPIV(+) or sCD26/DPPIV(−), and with or without the DPPIV inhibitor P32/98 (10 µM). The cells were then cultured for the indicated periods. They were fixed and subjected to ChIP analysis. Each panel shows a typical example of the results. Values represent mean ± S.E.M., n = 3, *<i>P</i><0.05 vs. control. **<i>P</i><0.05 vs. stimulation by LPS alone. ^#<i>P</i><0.05 vs. sCD26/DPPIV(+). Statistical analysis was performed using Student’s <i>t-</i>test.