フローサイトメトリー法による末梢血骨髄系樹状細胞検出法の考察

Abstract

Dendritic cells are strong antigen-presenting cells. Recently, antitumor immunity therapy using dendritic cells (DC therapy) has received attention. The clinical study of DC therapy for malignant diseases has been undertaken, and both cases of being effective responded and tumor-specific CTL-induced have been reported. However, no specific procedure for DC therapy has yet been established, so further detailed investigation is necessary. To perform a clinical study of such cell therapy, the technique for detecting and determining the cells to be used is critical. In this study, we devised a technique of deetecting peripheral myeloid dendritic cells by three-color flow cytometry. Gates were set for HLA-DR^+/CD33^+/CD14^- CD16^- CD34^- cells to determine one hundred thousands collected cells, leading to the clear identification of a cell population as being myeloid dendritic cells. The surface characteristics of this cell population were determined to be negative for CD3, CD19 and CD56, positive for CD2 and CD4, weakly positive for CD5, positive for CD11a and CD11c, negative to weakly positive for CD11b, negative for CD1a, CD80 and CD83, and positive for CD86. Such characteristics agree well with those previous- ly reported for peripheral myeloid dendritic cells. Thus, peripheral myeloid dendritic cells were judged to have been identified by this technique. The proportion of myeloid dendritic cells in normal subjects was 0.74±0.17%, with absolute numbers of 17.54±5.80/μl. In patients with chronic CML, incipient or recurrent malignant lymphoma, and acute leukemia in remission phase, the proportion of myeloid dendritic cells was reduced, suggesting a decrease in immunologic surveillance function. In patients with malignant lymphoma, following autologous peripheral blood stem cell transplantation, the proportion of myeloid dendritic cells was increased, representing the clinical effect of immunotherapy by autologous peripheral blood stem cell transplantation. This technique can readily deter- mine exact numbers of peripheral myeloid dendritic cells and will contribute to the future study of dendritic cells and the development of DC therapy.