Dual-targeting triplebody 33-16-123 (SPM-2) mediates effective redirected lysis of primary blasts from patients with a broad range of AML subtypes in combination with natural killer cells

2区 · 医学

ArticleOA

作者: Fenn, Nadja C. ; Subklewe, Marion ; Hopfner, Karl-Peter ; Schubert, Ingo A. ; Krupka, Christina ; Spiekermann, Karsten ; Krause, Stefan ; Schiller, Christian B. ; Roskopf, Claudia C. ; Jacob, Uwe ; Fey, Georg H. ; Oduncu, Fuat S. ; Mackensen, Andreas ; Wildenhain, Sarah ; Aigner, Michael ; Honegger, Annemarie ; Braciak, Todd A.

A number of agents designed for immunotherapy of Acute Myeloid Leukemia (AML) are in preclinical and early clinical development. Most of them target a single antigen on the surface of AML cells. Here we describe the development and key biological properties of a tri-specific agent, the dual-targeting triplebody SPM-2, with binding sites for target antigens CD33 and CD123, and for CD16 to engage NK cells as cytolytic effectors. Primary blasts of nearly all AML patients carry at least one of these target antigens and the pair is particularly promising for the elimination of blasts and leukemia stem cells (LSCs) from a majority of AML patients by dual-targeting agents. The cytolytic activity of NK cells mediated by SPM-2 was analyzed in vitro for primary leukemic cells from 29 patients with a broad range of AML-subtypes. Blasts from all 29 patients, including patients with genomic alterations associated with an unfavorable genetic subtype, were lysed at nanomolar concentrations of SPM-2. Maximum susceptibility was observed for cells with a combined density of CD33 and CD123 above 10,000 copies/cell. Cell populations enriched for AML-LSCs (CD34pos and CD34pos CD38neg cells) from 2 AML patients carried an increased combined antigen density and were lysed at correspondingly lower concentrations of SPM-2 than unsorted blasts. These initial findings raise the expectation that SPM-2 may also be capable of eliminating AML-LSCs and thus of prolonging survival. In the future, patients with a broad range of AML subtypes may benefit from treatment with SPM-2.

2013-11-23·Bioscience, Biotechnology, and Biochemistry4区 · 工程技术

Sweet Potatoes as a Basic Component in Developing a Medium for the Cultivation of Lactobacilli

4区 · 工程技术

Article

作者: Saddam S. Awaisheh ; Salam A. Ibrahim ; Nagendra P. Shah ; Saeed A. Hayek ; Aboghasem Shahbazi

A sweet potato medium (SPM) was formed with extract from baked sweet potatoes supplemented with 0, 4, or 8 g/L of each nitrogen source (beef extract, yeast extract, and proteose peptone #3) to form SPM1, SPM2, and SPM3 respectively. Lactobacilli MRS was used as control medium. Ten Lactobacillus strains containing an average of 2.34 ± 0.29 log CFU/mL were inoculated individually into batches of MRS, SPM1, SPM2, and SPM3. The growth patterns for the tested Lactobacillus strains growing in SPM2 and SPM3 were found to be similar to that in MRS. The average final population after 24 h of incubation in MRS, SPM2, and SPM3 reached 10.41 ± 0.35, 10.59 ± 0.27, and 10.72 ± 0.19 log CFU/mL respectively. SPM2 and SPM3 maintained higher pH values throughout the incubation period than MRS. These findings indicate that SPM2 can be a suitable medium for the growth of Lactobacillus and can provide an alternative at low-cost.

2013-01-01·Journal of Translational Medicine2区 · 医学

NK cells from an AML patient have recovered in remission and reached comparable cytolytic activity to that of a healthy monozygotic twin mediated by the single-chain triplebody SPM-2

2区 · 医学

ArticleOA

作者: Karl-Peter Hopfner ; Sarah Wildenhain ; Ingo A Schubert ; Uwe Jacob ; Fuat S Oduncu ; Claudia C Roskopf ; Georg H Fey ; Todd A Braciak

BACKGROUNDThe capacity of patient's Natural Killer cells (NKs) to be activated for cytolysis is an important prerequisite for the success of antibody-derived agents such as single-chain triplebodies (triplebodies) in cancer therapy. NKs recovered from AML patients at diagnosis are often found to be reduced in peripheral blood titers and cytolytic activity. Here, we had the unique opportunity to compare blood titers and cytolytic function of NKs from an AML patient with those of a healthy monozygotic twin. The sibling's NKs were compared with the patient's drawn either at diagnosis or in remission after chemotherapy. The cytolytic activities of NKs from these different sources for the patient's autologous AML blasts and other leukemic target cells in conjunction with triplebody SPM-2, targeting the surface antigens CD33 and CD123 on the AML cells, were compared.METHODSPatient NKs drawn at diagnosis were compared to NKs drawn in remission after chemotherapy and a sibling's NKs, all prepared from PBMCs by immunomagnetic beads (MACS). Redirected lysis (RDL) assays using SPM-2 and antibody-dependent cellular cytotoxicity (ADCC) assays using the therapeutic antibody RituximabTM were performed with the enriched NKs. In addition, MACS-sorted NKs were analyzed for NK cell activating receptors (NCRs) by flow cytometry, and the release of TNF-alpha and IFN-gamma from blood samples of both siblings after the addition of the triplebody were measured in ELISA-assays.RESULTSPatient NKs isolated from peripheral blood drawn in remission produced comparable lysis as NKs from the healthy twin against the patient's autologous bone marrow (BM) blasts, mediated by SPM-2. The NCR receptor expression profiles on NKs from patient and twin were similar, but NK cell titers in peripheral blood were lower for samples drawn at diagnosis than in remission.CONCLUSIONSPeripheral blood NK titers and ex vivo cytolytic activities mediated by triplebody SPM-2 were comparable for cells drawn from an AML patient in remission and a healthy twin. If these results can be generalized, then NKs from AML patients in remission are sufficient in numbers and cytolytic activity to make triplebodies promising new agents for the treatment of AML.

100 项与 SPM-2 相关的药物交易

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