Aurora-A kinase: a novel target of cellular immunotherapy for leukemia

Abstract

Aurora-A kinase (Aur-A) is a member of the serine/threonine kinase family that regulates the cell division process, and has recently been implicated in tumorigenesis. In this study, we identified an antigenic 9-amino-acid epitope (Aur-A207-215: YLILEYAPL) derived from Aur-A capable of generating leukemia-reactive cytotoxic T lymphocytes (CTLs) in the context of HLA-A*0201. The synthetic peptide of this epitope appeared to be capable of binding to HLA-A*2402 as well as HLA-A*0201 molecules. Leukemia cell lines and freshly isolated leukemia cells, particularly chronic myelogenous leukemia (CML) cells, appeared to express Aur-A abundantly. Aur-A-specific CTLs were able to lyse human leukemia cell lines and freshly isolated leukemia cells, but not normal cells, in an HLA-A*0201- restricted manner. Importantly, Aur-A- specific CTLs were able to lyse CD34+ CML progenitor cells but did not show any cytotoxicity against normal CD34 + hematopoietic stem cells. The tetramer assay revealed that the Aur-A207-215 epitope-specific CTL precursors are present in peripheral blood of HLAA* 0201-positive and HLA-A*2402- positive patients with leukemia, but not in healthy individuals. Our results indicate that cellular immunotherapy targeting Aur-A is a promising strategy for treatment of leukemia. © 2009 by The American Society of Hematology.