FIG. 3.

Neutralization-inhibition experiments using murine anti-human TLR1 and TLR2 monoclonal antibodies demonstrate the critical role that the TLR2-TLR1 complex plays in cellular activation by AmB. AmB-induced secretion of TNF-α (A), IL-6 (B), and IL-8 (C) by THP1 cells is inhibited by preincubation with anti-TLR2 monoclonal antibody, compared to results with cells preincubated with an MAb isotype control. Likewise, cytokine secretion in response to the TLR2 ligands PGN and Pam-3-Cys was inhibited by anti-TLR2 MAb (D). Preincubation of THP1 cells with murine anti-human TLR1 MAb inhibited TNF-α and IL-6 (E) and IL-8 (F) secretion in response to AmB. Anti-TLR1 MAb also inhibited IL-8 secretion in response to the TLR2-TLR1 ligand Pam-3-Cys but not to PGN and TNF-α (F).