HoloAlt a 1 significantly reduces the frequency of competent antigen-presenting cells. Flowcytometric analyses of PBMCs (n = 20) stimulated with medium (white circles), apoAlt a 1 alone (red circles) or in combination with iron–quercetin (holoAlt a 1_FeQ2, green circles)). (a) Gating strategy and (b) relative numbers of CD14+ in the monocytic gate, with further gating to (c) CD86+ or (d) HLADR+ with the respected summary of relative numbers in the monocytic gate. (e) Gating of CD14+ cells for HLADR + CD86+ expression and summary of relative numbers thereof. RM one-way ANOVA, with the Geisser–Green house correction, followed by Tukey’s multiple comparison test, with individual variances computed for each comparison. * p < 0.05; ** p < 0.01,*** p < 0.001; **** p < 0.0001.