Figure 2. LNG inhibits human DC function.

(a–c) Negatively selected human DCs were LNG-treated and poly I:C stimulated as described in Fig. 1, then co-cultured with CTV-labeled naïve allogeneic T cells. Co-cultures were maintained 7 days, then T cells immunostained for flow cytometric analysis of proliferation. (a) Representative contour plots of CD4⁺ T cell proliferation from co-cultures with untreated or LNG (4 μM)-treated DCs (numbers denote percentages of proliferating CD3ε⁺CD4⁺ T cells). (b–c) Proliferation of (b) CD4⁺ and (c) CD8⁺ T cells from co-cultures with untreated or LNG-treated DCs (data from 6 independent experiments normalized and analyzed as detailed in Materials and Methods); (bars indicate means ± SD). (d–f) CTV-labeled naïve allogeneic T cells were incubated with LNG or vehicle overnight, then stimulated with beads coated with anti-CD3 and anti-CD28 antibodies. T cell cultures were maintained 5 days, and cells immunostained for flow cytometric analysis of proliferation. (d) Representative contour plots of T cell proliferation (4 μM LNG); (numbers identify percentages of proliferating CD3ε⁺CD4⁺ T cells). Proliferation of (e) CD4⁺ and (f) CD8⁺ T cells in T cell-only cultures treated with vehicle or LNG (data from 6 independent experiments that were normalized and analyzed as defined in Materials and Methods); (bars denote means ± SD). All statistical analyses were performed using 1-way ANOVA with Dunnett’s multiple comparisons test, ****p < 0.0001.