Characterization of purified DC population.

(A) FACS profile of the enriched DC population. DCs were purified by a depletion of lineage-positive cells followed by repeated positive selection for CD4^low cells. This figure shows the resultant purified DC population obtained from an allogeneic transplantation patient. As shown, the DC population as characterized by DR⁺, lineage⁻ population constitutes approximately 93.4% of the cells. (B) Morphologic analysis of peripheral blood DC from a patient after allogeneic transplantation. Peripheral blood DCs derived from a patient after allogeneic transplantation were immunomagnetically purified and terminally matured overnight with TNF-α. DCs were then cytocentrifuged and stained with Giemsa. The studies were visualized by light microscopy at × 60 magnification. (C) Allogeneic mixed leukocyte reaction stimulation by DCs from a patient after allogeneic transplantation compared with PBMCs from a healthy donor. Proliferative response of third-party PBMCs to DCs from a patient after allogeneic hematopoietic cell transplantation (■) or to PBMCs from a healthy donor (◊). The mean of triplicates is shown. Vertical bars represent the SD. Counts per minute (cpm) reflect cell proliferation, shown at different stimulator-to-responder ratios (1:100, 1:333, 1:1000, and 1:3333).