Hitomi Nagayama

TGF-β1 Reciprocally Controls Chemotaxis of Human Peripheral Blood Monocyte-Derived Dendritic Cells Via Chemokine Receptors

We examined the effect of TGF-β1 on the chemotactic migratory ability of human monocyte-derived dendritic cells (DCs). Treatment of immature DCs with TGF-β1 resulted in increased expressions of CCR-1, CCR-3, CCR-5, CCR-6, and CXC chemokine receptor-4 (CXCR-4), which were concomitant with enhanced chemotactic migratory responses to their ligands, RANTES (for CCR-1, CCR-3, and CCR-5), macrophage-inflammatory protein-3α (MIP-3α) (for CCR-6), or stromal cell-derived growth factor-1α (for CXCR-4). Ligation by TNF-α resulted in down-modulation of cell surface expressions of CCR-1, CCR-3, CCR-5, CCR-6, and CXCR-4, and the chemotaxis for RANTES, MIP-3α, and stromal cell-derived growth factor-1α, whereas this stimulation up-regulated the expression of CCR-7 and the chemotactic ability for MIP-3β. Stimulation of mature DCs with TGF-β1 also enhanced TNF-α-induced down-regulation of the expressions of CCR-1, CCR-3, CCR-5, CCR-6, and CXCR-4, and chemotaxis to their respective ligands, while this stimulation suppressed TNF-α-induced expression of CCR-7 and chemotactic migratory ability to MIP-3β. Our findings suggest that TGF-β1 reversibly regulates chemotaxis of DCs via regulation of chemokine receptor expression.

IL-12 Responsiveness and Expression of IL-12 Receptor in Human Peripheral Blood Monocyte-Derived Dendritic Cells

We analyzed the expression of IL-12Rβ1 and IL-12Rβ2 and the role of IL-12 in the activation of monocyte-derived dendritic cells (DCs) via IL-12Rβ1-mediated signaling events. Flow cytometric analysis revealed that IL-12Rβ1 was expressed in T cells, Con A blasts, and monocyte-derived DCs, but not in monocytes, while its transcript was detected in all of these cell types. Transcriptional expression of IL-12Rβ2 was observed in T cells, Con A blasts, and monocyte-derived DCs, but not monocytes. The ligation of DCs as well as Con A blasts by IL-12 induced the production of GM-CSF, IL-1β, IL-6, TNF-α, and IFN-γ at the transcription levels. Furthermore, stimulation of DCs with IL-12 induced IL-12p40 transcript, but not IL-12p35 transcript, whereas this stimulation caused the expressions of both transcripts in Con A blasts. Stimulation of DCs with IL-12 caused a tyrosine phosphorylation of several intracellular proteins, and the pattern of these events were distinct from those of IL-12-stimulated Con A blasts. IL-12 also induced tyrosine phosphorylation of IL-12Rβ1 as well as recruitment of several tyrosine-phosphorylated proteins to IL-12Rβ1 in DCs and Con A blasts. Receptor engagement of DCs as well as Con A blasts by IL-12 resulted in activation of Janus kinase 2 and Tyk2 kinases and Stat3 and Stat4 transcription factors and the association of these proteins to IL-12Rβ1. Stimulation with IL-12 caused a tyrosine phosphorylation and enzymatic activity of a family of mitogen-activated protein kinases, p38mapk. These results suggest that IL-12 acts directly on DCs to induce their functional activation via IL-12Rβ1-mediated signaling events.

Results of a phase I clinical study using autologous tumour lysate-pulsed monocyte-derived mature dendritic cell vaccinations for stage IV malignant melanoma patients combined with low dose interleukin-2

We conducted a pilot study to assess the feasibility and efficacy of immunotherapy for stage IV malignant melanoma patients resistant to conventional therapies involving vaccination with mature dendritic cells (mDCs) combined with administration of low dose interleukin-2. Autologous monocytes were harvested from a single apheresis and cultured for 7 days with granulocyte–macrophage colony-stimulating factor and interleukin-4, yielding immature dendritic cells (iDCs), which were then cryopreserved until use. For 4 days prior to vaccination, iDCs were exposed to autologous tumour lysate combined with tumour necrosis factor-α to induce terminal differentiation into mDCs. Patients were then vaccinated weekly with 107 mDCs for 10 weeks and given 350–700 kIU of interleukin-2 three times per week. Of the 10 patients in the study, one showed stable disease, seven showed progressive disease, and two showed mixed responses, including partial tumour regression, and were therefore given 20 additional injections. Only minimal adverse events were noted, including localized skin reactions and mild fever (NIH-CTC grade 0–1). Median survival from the first vaccination was 240 days (range 31–735 days). In vitro, melanoma patient-derived dendritic cells (DCs) showed reduced cell surface expression of CD1a antigen on iDCs and reduced CD86 and HLA-DR expression on mDCs. In addition, antigen uptake, chemotaxis and antigen presentation were all attenuated in DCs from the patients. In summary, although improvement of clinical efficacy will require further research, autologous tumour lysate-pulsed monocyte-derived mDCs could be safely harvested, cryopreserved and administrated to patients without obvious complications.

A clinical comparison of unrelated cord blood transplantation and unrelated bone marrow transplantation for adult patients with acute leukaemia in complete remission

Summary.  We performed a clinical comparison of unrelated cord blood transplantation (UCBT) and unrelated bone marrow transplantation in adult acute leukaemia patients in complete remission (CR) who received the same conditioning regimen, graft‐versus‐host disease (GvHD) prophylaxis and supportive treatment. The incidence of acute GvHD was almost the same between the two groups, but the haematopoietic recovery was delayed and the incidence of chronic GvHD was higher in the UCBT group. The probability of 2 year disease‐free survival was similar between the two groups. These results suggest that adult acute leukaemia patients in CR without a suitable donor should be considered as candidates for UCBT.

Chemokine Receptor Expressions and Responsiveness of Cord Blood T Cells

Chemokines and their receptors play a critical role in the selective attraction of various subsets of leukocytes. We examined the chemokine receptor expressions and responsiveness of cord blood (CB) T cells. Flow-cytometric analysis revealed that peripheral blood (PB) T cells expressed CCR-1, CCR-2, CCR-5, CCR-6, CXC chemokine receptor-3 (CXCR-3), and CXCR-4, while CB T cells expressed only CXCR-4 on their surface. Chemotactic migratory response of CB T cells to macrophage-inflammatory protein (MIP)-1α, monocyte chemoattractant protein-1, RANTES, MIP-3α, monokine induced by IFN-γ, and IFN-γ-inducible protein-10 was significantly impaired compared with those of PB T cells. In contrast, the ability of CB T cells to migrate to MIP-3β, 6Ckine, and stromal cell-derived factor-1α was greater than that of PB T cells, and these events were correlated with the expression levels of CCR-7 and CXCR-4, respectively. Engagement of CD3 and CD28 specifically up-regulated CXCR-3 expression and chemotaxis to monokine induced by IFN-γ and IFN-γ-inducible protein-10, whereas this stimulation down-regulated CCR-7 expression and chemotaxis to MIP-3β and 6Ckine in PB T cells, but not in CB T cells. These results suggest that PB T cells and CB T cells exhibit distinct chemokine responsiveness via different chemokine receptor repertoire.

Interleukin-13 is involved in functional maturation of human peripheral blood monocyte-derived dendritic cells

Dendritic cells (DCs) are professional antigen presenting cells (APCs) that are required for the initiation of the immune response. DCs have been shown to be generated from hematopoietic stem cells, but relatively little is known about the regulation underlying differentiation and activation of DCs. Here, we report that recombinant human (rh)IL-13 induces functional maturation of rhGM-CSF plus rhIL-4 generated monocyte-derived immature DCs. Incubation of these immature DCs with rhIL-13 or rhTNF-alpha for 2 days resulted in increased surface expression of CD1a, CD11c, CD86 and HLA-DR. The DCs treated with rhIL-13 or rhTNF-alpha, but not rhIL-4, for 2 days were more efficient than unstimulated DCs in the primary autologous/allogeneic T-cell response whereas the antigen (Ag)-specific T-cell response was suppressed. The treatment of DCs with rhIL-13 as well as rhTNF-alpha for 4 days down-modulated endocytic capacity for FITC-dextran (FITC-DX) and lucifer yellow (LY), and induced surface expression of CD83. Morphological, phenotypical, and functional analyses revealed that the monocytes cultured with rhGM-CSF plus rhIL-13 gave rise to a DC type more mature than rhGM-CSF plus rhIL-4-induced DCs. These findings revealed a new role for rhIL-13 in regulating both the maturation and activation of DCs.

Unrelated cord blood transplantation for adult patients with myelodysplastic syndrome-related secondary acute myeloid leukaemia

Seven adult patients with myelodysplastic syndrome (MDS)‐related secondary acute myeloid leukaemia (AML) were treated with total body irradiation (TBI), cytosine arabinoside (Ara‐C) and cyclophosphamide (CY), followed by unrelated human leucocyte antigen (HLA)‐mismatched cord blood transplantation (CBT). Granulocyte colony‐stimulating factor (G‐CSF) was infused continuously from 12 h before until the end of Ara‐C therapy to enhance the antileukaemia effect of Ara‐C. Five patients are alive and free of disease at 7–31 months after transplantation. These preliminary results suggest that adult MDS‐related secondary AML patients without suitable related or unrelated bone marrow donors should be considered as candidates for CBT.

Immunological reconstitution after cord blood transplantation for an adult patient

We transplanted 4.1 × 107 unrelated umbilical cord blood cells into a 27-year-old patient suffering from transformed acute myelocytic leukemia. The thawing method was the same as described by Rubinstein et al (Proc Natl Acad Sci USA 1995; 92: 10119–10122). ANC reached over 500 × 109/l on day 19, and the patient was free from RBC and platelet transfusion on days 26 and 38, respectively. Cytogenetic and molecular analysis after transplant revealed complete chimerism. The CD3+CD4+ lymphocyte count became greater than 100 × 109/l at 5 weeks after transplantation. The CD3+CD8+ count became greater than 500 × 109/l at 7 weeks and thereafter progressively increased in spite of administration of CYA. This immunological reconstitution pattern after umbilical cord blood transplantation was different from that after bone marrow transplantation, and resistance of CD3+CD8+ lymphocytes to CYA was the distinguishing characteristic. The rapid hematological recovery and immunological reconstitution may be attributed to the high dose of transfused nucleated cells and umbilical cord blood transplantation may become a promising method for treatment for such cases.

Severe Immune Dysfunction after Lethal Neutron Irradiation in a JCO Nuclear Facility Accident Victim

The optimal treatment for the hematological toxicity of acute radiation syndrome (ARS) is not fully established, especially in cases of high-dose nonuniform irradiation by mixed neutrons and γ-rays, because estimation of the irradiation dose (dosimetry) and prediction of autologous hematological recovery are complicated. For the treatment of ARS, we performed HLA-DRB1—mismatched unrelated umbilical cord blood transplantation (CBT) for a nuclear accident victim who received 8 to 10 GyEq mixed neutron and γ-ray irradiation at the JCO Co. Ltd. nuclear processing facility in Tokaimura, Japan. Donor/ recipient mixed chimerism was attained; thereafter rapid autologous hematopoietic recovery was achieved in concordance with the termination of immunosuppressants. Immune function examined in vitro showed recovery of the autologous immune system was severely impaired. Although the naive T-cell fraction and the helper T-cell subtype 1 fraction were increased, the mitogenic responses of T-cells and the allogeneic mixed leukocyte reaction were severely suppressed. Endogenous immunoglobulin production was also suppressed until 120 days after the accident. Although skin transplantation for ARS was successful, the patient died of infectious complications and subsequent acute respiratory distress syndrome 210 days after the accident. These results suggest that fast neutrons in doses higher than 8 to 10 Gy cause complete abrogation of the human immune system, which may lead to fatal outcome even if autologous hematopoiesis recovers. The roles of transplantation, autologous hematopoietic recovery, chimerism, immune suppression, and immune function are discussed.

Second Allogeneic Hematopoietic Stem Cell Transplantation for Leukemia Relapse After First Allogeneic Transplantation: Outcome of 16 Patients in a Single Institution

Sixteen patients who underwent a second allogeneic hematopoietic stem cell transplantation (HSCT2) for leukemia relapse after the first allogeneic transplantation (HSCT1) were studied. The patients included 7 patients with acute myelogenous leukemia, 8 with acute lymphoblastic leukemia, and 1 with chronic myelogenous leukemia.The median patient age at HSCT2 was 22 years (range, 12 to 44 years).The median interval between HSCT1 and HSCT2 was 19 months (range, 2 to 46 months). At HSCT2, 7 patients were in complete remission (CR), 7 had relapsed, and 2 had bone marrow aplasia. In 14 patients, donors for HSCT2 were the same as those for HSCT1. Two donors were replaced, 1 for another HLA-matched sibling and 1 for an unrelated cord blood donor. Four patients (25%) died within 100 days after HSCT2 from veno-occlusive disease, sepsis, interstitial pneumonitis, or chronic graft-versus-host disease (GVHD), without leukemia relapse. Seven patients (44%) developed leukemia relapse and died between 4 and 20 months after HSCT2. Five patients (31%) survived beyond 4 years. One patient died from chronic GVHD without leukemia relapse 55 months after HSCT2. The 4 other patients were alive between 79 and 134 months after HSCT2 (median follow-up, 106 months). Factors that favorably influenced survival were age younger than 20 years and CR duration after HSCT1 longer than 12 months. HSCT2 is considered to be beneficial for select patients. Preparative regimens, GVHD prophylaxis, and donor choice for HSCT2 need to be studied to obtain a more successful outcome for HSCT2.