Flt3 ligand promotes myeloid dendritic cell differentiation of human hematopoietic progenitor cells: possible application for cancer immunotherapy.

Current in vitro culture systems allow the generation of human dendritic progenitor cells (CFU-DCs). The aim of this study was to assess the effect of Flt3 ligand (FL) on the proliferation of human peripheral blood-derived myeloid CFU-DCs and their differentiation into more committed precursor cells (pDCs) using in vitro culture systems. Immunomagnetically separated CD34+ cells were cultured in serum-free, as well as in serum-containing, liquid suspension cultures to investigate the expansion and/or proliferation/differentiation of CFU-DCs, pDCs, and more mature dendritic cells (DCs).

Successful induction of clinically competent dendritic cells from granulocyte colony-stimulating factor-mobilized monocytes for cancer vaccine therapy.

Recent studies have suggested that dendritic cell (DC)-based immunotherapy is one promising approach for the treatment of cancer. We previously studied the clinical toxicity, feasibility, and efficacy of cancer vaccine therapy with peptide-pulsed DCs. In that study, we used granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood monocytes as a cell source of DCs.

Mobilization of peripheral blood stem cells (PBSCs) after etoposide, adriamycin and cisplatin therapy, and a multimodal cell therapy approach with PBSCs in advanced gastric cancer.

The EAP combination of etoposide (ETP), doxorubicin (ADM) and cisplatin (CDDP) has been reported to be highly active for advanced gastric cancer. However, it is associated with severe myelotoxicity, and its use has declined. We examined whether peripheral blood stem cells (PBSCs) could be mobilized during hematopoietic recovery after EAP, and assessed the possibility of using multimodal cell therapy with PBSCs for the treatment of advanced gastric cancer.

Streptococcal preparation OK432 promotes functional maturation of human monocyte-derived dendritic cells.

Streptococcal preparation OK432 is an immunomodulatory agent extensively used as adjuvant therapy for gastric cancer in Japan. OK432 augments the cytotoxic activity of various effector cells such as lymphocytes, macrophages and (natural killer) NK cells and induces the production of multiple cytokines. Dendritic cells (DC) are professional antigen-presenting cells (APC) that can be used for cancer vaccine therapy.

Role of human interleukin-9 as a megakaryocyte potentiator in culture.

Objective: This study investigated the effect of interleukin-9 (IL-9) on the proliferation and differentiation of human colony-forming unit megakaryocytic progenitor cells (CFU-Meg).

Materials And Methods: Peripheral blood-derived CD34(+)IL-6R(-) cells were sorted and cultured in the presence of IL-9, erythropoietin (Epo), stem cell factor (SCF), and thrombopoietin (TPO) alone or in combination. The number of pure and mixed megakaryocyte colonies, the size of pure megakaryocyte colonies, the ploidy distribution of megakaryocytes, and proplatelet formation were investigated.

SCID-repopulating cell activity of human cord blood-derived CD34- cells assured by intra-bone marrow injection.

Precise analysis of human CD34-negative (CD34(-)) hematopoietic stem cells (HSCs) has been hindered by the lack of a simple and reliable assay system of these rare cells. Here, we successfully identify human cord blood-derived CD34(-) severe combined immunodeficiency (SCID)- repopulating cells (SRCs) with extensive lymphoid and myeloid repopulating ability using the intra-bone marrow injection (IBMI) technique. Lineage-negative (Lin(-)) CD34(-) cells did not show SRC activity by conventional tail-vein injection, possibly due to their low levels of homing receptor expression and poor SDF-1/CXCR4- mediated homing abilities, while they clearly showed a high SRC activity by IBMI.