CD64-directed microtubule associated protein tau kills leukemic blasts ex vivo
نویسندگان
چکیده
Fc gamma receptor I (FcγRI, CD64) is a well-known target antigen for passive immunotherapy against acute myeloid leukemia and chronic myelomonocytic leukemia. We recently reported the preclinical immunotherapeutic potential of microtubule associated protein tau (MAP) against a variety of cancer types including breast carcinoma and Hodgkin's lymphoma. Here we demonstrate that the CD64-directed human cytolytic fusion protein H22(scFv)-MAP kills ex vivo 15-50% of CD64+ leukemic blasts derived from seven myeloid leukemia patients. Furthermore, in contrast to the nonspecific cytostatic agent paclitaxel, H22(scFv)-MAP showed no cytotoxicity towards healthy CD64+ PBMC-derived cells and macrophages. The targeted delivery of this microtubule stabilizing agent therefore offers a promising new strategy for specific treatment of CD64+ leukemia.
منابع مشابه
P 97: Neurodegeneration Induced by Tau protein
Tau is one of several types of microtubule-associated proteins (MAPs), responsible for the assembly and stability of microtubule networks that is present only in neurons and predominantly localized in axons which its functions are tightly regulated by phosphorylation. Via as yet unknown mechanisms, tau becomes hyperphosphorylated and accompanies with neuronal degeneration, loss of synapses...
متن کاملProline-directed phosphorylation of human Tau protein.
The primary sequence of the microtubule-associated protein tau contains multiple repeats of the sequence -X-Ser/Thr-Pro-X-, the consensus sequence for the proline-directed protein kinase (p34cdc2/p58cyclin A). When phosphorylated by proline-directed protein kinase in vitro, tau was found to incorporate up to 4.4 mol of phosphate/mol of protein. Isoelectric focusing of the tryptic phosphopeptide...
متن کاملAltered multidrug resistance phenotype caused by anthracycline analogues and cytosine arabinoside in myeloid leukemia.
The expression of P-glycoprotein (Pgp) is often increased in acute myeloid leukemia (AML). However, little is known of the regulation of Pgp expression by cytotoxics in AML. We examined whether Pgp expression and function in leukemic blasts was altered after a short exposure to cytotoxics. Blasts were isolated from 19 patients with AML (15 patients) or chronic myeloid leukemia in blastic transf...
متن کاملModulation of tau phosphorylation and intracellular localization by cellular stress.
Tau is a microtubule-associated protein that is functionally modulated by phosphorylation and hyperphosphorylated in several neurodegenerative diseases. Because phosphorylation regulates both normal and pathological tau functioning, it is of great interest to identify the signalling pathways and enzymes capable of modulating tau phosphorylation in vivo. The present study examined changes in tau...
متن کاملMicrotubule-affinity regulating kinase (MARK) is tightly associated with neurofibrillary tangles in Alzheimer brain: a fluorescence resonance energy transfer study.
Paired helical filaments, the main structural components of the neurofibrillary tangles in Alzheimer disease, consist of phosphorylated tau protein. Because the levels and degree of phosphorylation are significantly higher in paired helical filament (PHF)-derived tau than in normal adult tau, and because phosphorylation of tau severely disrupts microtubule stability, it is postulated that tau p...
متن کامل