FIGURE 9.

Inhibitory effect of LOS-IV on TNF-α secretion in differentiated THP-1 cells. Cells were preincubated for 20 h with increasing concentrations of LOS-IV isolated from MmaM and then stimulated with LPS or Pam₃CSK₄ (20 ng/ml). Culture supernatants were collected after 6 h of induction and assayed by ELISA for TNF-α secretion. The results presented are from one representative experiment of three independent experiments with similar results. Comparable results were obtained using different batches of THP-1 cells and different LOS-IV preparations. Data are expressed as means ± S.D. of triplicate plates. Statistical analyses were performed by using Student's t test to compare LOS-IV-pretreated cells with nontreated cells. The p values were <0.0023 and <0.0003 in comparison with LPS- or Pam₃CSK₄-stimulated cells, respectively.