Figure 5.

TCDD-mediated AHR activation increases LCK expression in CD5⁺ but not CD5^- human B cells. CD19⁺ naïve B cells were isolated from PBMC and further enriched into CD5⁺ and CD5^- B cell populations. Cells were then activated and treated with 10nM TCDD as described previously. Cells were collected on day 3 post activation and surface stained for CD19, permeabilized and incubated with an anti-LCK antibody for quantification of intracellular LCK protein expression by flow cytometry. Representative flow plots are shown in panel (A). LCK⁺ cells were identified in the lymphocyte singlet gate by gating on live CD19⁺ cells. Averaged results from 3 independent experiments assessing a total of 9 human donors are shown in (B). Expression of LCK protein normalized to Veh control is shown in (C). A repeated measure one-way ANOVA with a Tukey’s posttest was used to determine significance. **p < 0.01.