Cellular levels of pDC1 (GM-CSFRα chain, CD13) versus pDC2 (IL-3Rα chain) induced by the addition of CD34⁺ cells to the bulk MLR. A 5-day MLR was established in which responder cells (1 × 10⁶/mL) were cocultured with irradiated allogeneic stimulator cells (1 × 10⁶/mL) from the CD34+ cell donor in the presence of CD34+ cells (0.5 × 10⁶/mL). At the indicated days of the MLR, cells were harvested and the expression of pDC1/pDC2 antigens was measured by immunofluorescent staining. CD34+ cells were analyzed in myelogate based on their FSC/SSC profile. The percentages of the cell subpopulations are indicated in the relevant area of the dot plot. Results represent 1 experiment.