NN-DMT and 5-MeO-DMT pre-treatment of pathogen-activated human dendritic cells effectively inhibit their capacity to prime autologous naive T helper 1 and T helper 17 cells.

<p>Dendritic cells were activated either by heat-killed <i>E. coli</i> (E. coli) or inactivated influenza virus (IV) for 24 h, washed, and then co-cultured with naive autologous CD4⁺ T lymphocytes for 4 days. The number of primed, IFNγ or IL-17 secreting T cells was assessed by ELISPOT assay. T cells alone (T-cell ctrl), and non-activated DCs treated with DMT and co-cultured with autologous naive CD4⁺ T lymphocytes (NN-DMT, 5-MeO-DMT) were used as controls. <b>A–B:</b> Induction of IFNγ (A) or IL-17 (B) production of autologous naive CD4⁺ T cells induced by moDC loaded by <i>E. coli</i>. Bacteria alone (E. coli; red bars) or bacteria in combination with 1 h DMT pre-treatment (E. coli + NN-DMT, E. coli+5-MeO-DMT; empty bars) were used to activate moDCs as written above. <b>C–D:</b> Cells were activated as in Fig4A–B; in this case inactivated influenza virus (IV) was added to the moDCs alone for 24 h (blue bars), or in combination with an 1 h NN-DMT or 5-MeO-DMT pre-treatment (IV + NN-DMT, IV + 5-MeO-DMT; empty bars). Data represent Mean + SEM values of triplicate measurements of three independent donors. Asterisk indicates statistical significance (<i>p</i><0.05).