Flow cytometry analysis of CD52 expression by different myeloid DC populations and their precursors.

Flow cytometric analyses were performed to determine CD52 surface expression by immature (surface CD83⁻, intracellular CD83⁺) and mature (CD83⁺) myeloid DCs and their precursors. T cells provided a positive control. Monocytes as well as their immature and mature moDC derivatives expressed abundant CD52, although the MFI decreased somewhat with maturation. Circulating, immature DCs, defined as CD11c⁺, lineage-negative (CD3⁻, CD14⁻, CD16⁻, CD20⁻) cells gated from total PBMCs, also expressed CD52 abundantly with an MFI comparable to that of T cells. A substantial proportion of CD34⁺ HPCs expressed CD52, although at a relatively low MFI compared with the positive T-cell control. CD11b⁻ LCs and CD11b⁺ DDC-IDCs displayed no detectable expression of CD52 above background, independent of the maturation state. The bold line histograms represent the reactivity of anti-CD52 MAb with the selected population, and broken line histograms depict the isotype control. One experiment representative of 3 is shown.