Human interleukin 2 (IL-2; Proleukin) is an approved therapeutic for advanced-stage metastatic cancer; however, its use is restricted because of severe systemic toxicity. Its function as a central mediator of T-cell activation may contribute to its efficacy for cancer therapy. However, activation of natural killer (NK) cells by therapeutically administered IL-2 may mediate toxicity. Here we have used targeted mutagenesis of human IL-2 to generate a mutein with approximately 3,000-fold in vitro selectivity for T cells over NK cells relative to wild-type IL-2. We compared the variant, termed BAY 50-4798, with human IL-2 (Proleukin) in a therapeutic dosing regimen in chimpanzees, and found that although the T-cell mobilization and activation properties of BAY 50-4798 were comparable to human IL-2, BAY 50-4798 was better tolerated in the chimpanzee. BAY 50-4798 was also shown to inhibit metastasis in a mouse tumor model. These results indicate that BAY 50-4798 may exhibit a greater therapeutic index than IL-2 in humans in the treatment of cancer and AIDS.

Functional dendritic cells (DC) are professional antigen presenting cells (APC) and can be generated in vitro from leukemic cells from acute myeloid leukemia AML patients, giving rise to APC of leukemic origin presenting leukemic antigens (DC(leu)). We have already shown that DC can be successfully generated from AML and myeloplastic syndromes (MDS) cells in serum-free 'standard' medium (X-vivo + GM-CSF + IL-4 +TNFalpha + FL) in 10-14 days. In this study, we present that DC counts generated from mononuclear cells (MNC) varied between 20% (from 55 MDS samples), 34% (from 100 AML samples) and 25% (from 38 healthy MNC samples) medium. Between 53% and 58% of DC are mature CD83+ DC. DC harvests were highest in monocytoid FAB types (AML-M4/M5, MDS-CMML) and independent from cytogenetic risk groups, demonstrating that DC-based strategies can be applied for patients with all cytogenetic risk groups. Proof of the clonal derivation of DC generated was obtained in five AML and four MDS cases with a combined FISH/immunophenotype analysis (FISH-IPA): The clonal numerical chromosome aberrations of the diseases were regularly codetectable with DC markers; however, not with all clonal cells being convertible to leukemia-derived DC(leu) (on average, 53% of blasts in AML or MDS). To the contrary, not all DC generated carried the clonal aberration (on average, 51% of DC). In 41 AML and 13 MDS cases with a suitable antigen expression, we could confirm FISH-IPA data by Flow cytometry: although DC(leu) are regularly detectable, on average only 57% of blasts in AML and 64% of blasts in MDS were converted to DC(leu). After coculture with DC in mixed lymphocyte reactions (MLR), autologous T cells from AML and MDS patients proliferate and upregulate costimulatory receptors. The specific lysis of leukemic cells by autologous T cells could be demonstrated in three cases with AML in a Fluorolysis assay. In six cases with only few DC(leu) or few vital T cells available after the DC/MLR procedure, no lysis of allogeneic or autologous leukemic cells was seen, pointing to the crucial role of both partners in the lysis process. We conclude: (1) the generation of DC is regularly possible in AML and also in MDS under serum-free conditions. (2) Clonal/leukemia-derived DC(leu) can be regularly generated from MDS and AML-MNC; however, not with all blasts being converted to DC(leu) and not all DC generated carrying leukemic markers. We recommend to select DC(leu) for vaccinations or ex vivo T-cell activations to avoid contaminations with non-converted blasts and non-leukemia-derived DC and to improve the harvest of specific, anti-leukemic T cells. DC and DC-primed T cells could provide a practical strategy for the immunotherapy of AML and MDS.

Fourteen children between the ages of 2 and 5 years with juvenile chronic myelogenous leukemia were given cyclophosphamide, total-body irradiation, and marrow transplants. Unmodified marrow was given to six patients who received marrow from HLA-identical siblings and eight patients who received marrow from family members HLA identical for one haplotype but mismatched for one to three loci on the nonshared haplotype. Five patients died of transplant-related complications, and three relapsed at 48, 81, and 1,670 days posttransplant and died of leukemia. Six patients survive in continuous remission from 0.5 to 11.5 years posttransplant.

Fourteen children between the ages of 2 and 5 years with juvenile chronic myelogenous leukemia were given cyclophosphamide, total-body irradiation, and marrow transplants. Unmodified marrow was given to six patients who received marrow from HLA-identical siblings and eight patients who received marrow from family members HLA identical for one haplotype but mismatched for one to three loci on the nonshared haplotype. Five patients died of transplant-related complications, and three relapsed at 48, 81, and 1,670 days posttransplant and died of leukemia. Six patients survive in continuous remission from 0.5 to 11.5 years posttransplant.

In seiner Arbeit tiber parenchymatSse Entztindung ~) their Virehow mit, dass er bei ausgesprochener Osteomalacie die Knochen yon einer weichen, zitternden Gallerte erftillt fand, welche an wenigea Stellen hellgelb und klar, an anderen und namentlich da, wo der Prozess noch in der Ausbildung begriifen war, dunkelroth erschien.