FIGURE 4.

Composition 8203 is a complete tolerogenic adjuvant for Treg cells. (A) Composition 8203 augments absolute expansion of KJ1-26⁺ Treg cells in DLN. The model was injected on day 5 at the primed footpad with OVA-in-PBS, OVA-in-Dex, or OVA-in-8203. DLN T cells were analyzed on day 8. The baseline of the model (on day 5) is shown as “Start.” Data are mean ± SD of six (for cell count analysis) or four (for Ki67 analysis) experiments. *p ≤ 0.001 and **p ≤ 0.001, for absolute and relative Treg counts, respectively, in the OVA-in-8203 injected versus any other group (one-way ANOVA). ***p ≤ 0.04, for % Ki67⁺ Treg cells in the OVA-in-8203 injected versus any other group (one-way ANOVA). (B) Composition 8203 has little effect on host Treg or Teff cells in the same DLN shown in A. Data are mean ± SD of six (count analysis) or four (Ki67 analysis) experiments. “ns,” not significant. (C) All the OVA-in-8203 components are required for absolute KJ1-26⁺ Treg cell expansion. The model was injected with indicated compositions and analyzed as in A. Data are mean ± SD of four experiments. *p ≤ 0.01 and **p ≤ 0.001, for absolute and relative counts, respectively, of KJ1-26⁺ Treg cells in the OVA-in-8203 treated (group 2) versus any other group (one-way ANOVA).