In cancer or hematologic disorders, chemokines act as growth-or survival factors, regulating hematopoiesis and angiogenesis, determining metastatic spread and controlling leukocyte infiltration into tumors to inhibit antitumor immune responses. The aim was to quantify the release of CXCL8, −9, −10, CCL2, −5, and IL-12 in AML/ MDS-pts' serum by cytometric bead array and to correlate data with clinical subtypes and courses. Minimal differences in serum-levels subdivided into various groups (e.g. age groups, FAB-types, blastproportions, cytogenetic-risk-groups) were seen, but higher release of CXCL8, −9, −10 and lower release of CCL2 and −5 tendentially correlated with more favorable subtypes (<50 years of age, <80% blasts in PB). Comparing different stages of the disease higher CCL5-release in persisting disease and a significantly higher CCL2release at relapse were found compared to first diagnosispointing to a change of 'disease activity' on a chemokine level. Correlations with later on achieved response to immunotherapy and occurrence of GVHD were seen: Higher values of CXCL8, −9, −10 and CCL2 and lower CCL5-values correlated with achieved response to immunotherapy. Predictive cut-off-values were evaluated separating the groups in 'responders' and 'non-responders'. Higher levels of CCL2 and −5 but lower levels of CXCL8, −9, −10 correlated with occurrence of GVHD. We conclude, that in AML-pts' serum higher values of CXCL8, −9, −10 and lower values of CCL5 and in part of CCL2 correlate with more favorable subtypes and improved antitumor'-reactive function. This knowledge can contribute to develop immune-modifying strategies that promote antileukemic adaptive immune responses.

To enlighten interactions between autologous, allogeneic or T-cells from patients after stem cell transplantation with leukaemia-derived-dendritic-cells containing dendritic cells or blast containing mononuclear cells (n ¼ 21, respectively), we determined cytokine-concentrations (interleukin 2, 4, 6, 10, tumor-necrosis-factor-a, interferon-c) in supernatants of mixed-lymphocyte-culture and in serum (n ¼ 16) of 20 patients with acute myeloid leukaemia and three patients with myelodysplastic syndromes by cytometric-bead-assay. We correlated our data with lytic capabilities of stimulated T-cells in a fluorolysis-assay and clinical data: Dendritic-cell-/mononuclear-cell-stimulation of T-cells resulted in increased cytokine-levels in culture-medium compared to serum. There were no significant differences between cytokine-patterns of cases with/without lytic T-cell-activity, response to immunotherapy (stem cell transplantation/donor-lymphocyte-infusion) or graft-versus-host-disease. However, some predictive cytokine-cut-off-values for antileukaemic T-cell-activity, patients' response to immunotherapy and graft-versus-host-disease could be defined. Cytokine-profiles alone, without functional assays, are no useful tool to predict antileukaemic T-cell-function, although they can indicate lytic T-cell-activity, patients' response to immunotherapy and graft-versus-host-disease. ARTICLE HISTORY

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Presentation of leukemic antigens (LAA) can be improved by conversion of leukemic cells to leukemia derived DC (DCleu), thereby enabling the generation of leukemia specific CTL. DC/DCleu can be generated and quantified from every AML case with at least one of 3 different DC generating methods (Schmetzer 2007/2008). We want to enlight the role of the composition and quality of DC and (DC or blast trained) T cells to mediate leukemia cytotoxic reactions or to predict the clinical response to therapy. Autologous patients’, allogeneic donor T cells or T cells at relapse after SCT were trained with DC or blasts from 25 AML-cases in a ‘Mixed lymphocyte culture’ (MLC) and DC/T cell profiles and antileukemic Tcell cytotoxicity evaluated. We generated DC/mature DC/DCleu from every patient (Ø27/45/83%). DC training of T cells increased proliferating, CD4+ and memory T cells and decreased CD8+ T cells; blast training did not increase memory T cells. An antileukemic, very efficient T cell cytotoxicity was achieved in 47% of cases after DC/DCleu training but only in 24% after blast training of T cells. A comparison of cases with a gain of antileukemic T cell cytotoxicity to those without a lytic activity showed higher proportions of mature DC/DCleu and CD4/memory T cells and higher amounts of secreted IFNgamma and IL 6 in the lytically active, DC trained group. The differences were most distinct in the group with DC trained T cells prepared at relapse after SCT. Cases with a response to therapy showed higher proportions of DCleu, proliferating, memory or CD4+ T cells. We showed that &gt;67% of all cases gained an antileukemic T cell cytotoxicity after DC training if &gt;45% proliferating/&gt;65% CD4+/&gt;42% memory T cells or &gt;40% mature DC/&gt;65% DCleu were in the DC training setting. Moreover, 90% of DC trained T cells gained a lytic activity if &gt;65% DCleu were in the MLC. AML patients presenting with a relapse after SCT showed better ex vivo convertibility of blasts to DCleu if they had responded to a GM CSF/DLI based therapy of their relapse after SCT compared to cases with no response (72 vs 36% blasts convertible to DCleu; 44 vs 29% generable DC). By spectratyping of the Vβ TCR region in an AML case we demonstrated a more extended clonal restriction of donor T cells after DC training of T cells compared to blast trained T cells. Moreover, the restricted pattern was also found in T cells from the patient after SCT. In summary, DC/DCleu can be generated in any given case independent from karyotype. A DC training of T cells improves the antileukaemic CTL, but can also mediate a T cell anergy. The composition of DC and T cells is predictive for the lytic efficiency of the trained T cells: A successful DC training of T cells is associated with high mature DC/DCleu counts and high rates of proliferating, CD4+ and memory T cells. Patients responding to a DLI/GM CSF based therapy are characterized by a better convertibility of blasts to DCleu and more mature DC. Identical clonal restrictions of T cells were found in blast trained and even more in DC trained T cells. Identical clonal patterns were found in ex vivo trained and in vivo selected T cells. We can contribute to understand biological mechanisms behind cytotoxic reactions and escape mechanisms and to develop adoptive immunotherapies with specific, antileukemia directed LAA specific T cells, e.g. selected by multimers from SCT donors or with specifically trained and selected T cells after DC training without side effects.