Fig. 2

Isolation of antigen presenting cells. a Peripheral blood mononuclear cells (PBMC) were elutriated into three fractions: small lymphocytes, large lymphocytes and a monocyte/DC fraction. Resting CD4⁺ T-cells were isolated from the small lymphocyte fraction by negative selection using magnetic beads. Bulk B-cells were isolated from a mixture of the small and large lymphocyte fractions using positive magnetic bead selection for CD19. Bulk DC subpopulations were positively selected on the basis of expression of CD1c, CD141, SLAN and CD123 from the DC/monocyte fraction using magnetic bead selection. The positive “DC enriched” (DC) population was then sorted by flow cytometry into the four DC populations (purity >95 %). The negative “DC depleted” (mono) fraction was labeled with the monocyte markers CD14 and CD16, positively selected using magnetic beads and further sorted by flow cytometry into CD14⁺ and CD14^loCD16^hi subsets (purity >90 %). b, c Representative dot plots and brightfield images show the purity and morphology of the sorted APC subpopulations, respectively. The scale bars represent 20 μm, images were annotated using ImageJ software