Antigen identified as possible immunotherapy for myeloid leukemias

07-28-2006

Researchers have identified an antigen that may work as an immunotherapy for myeloid leukemias.

According to recent research from Switzerland, "Three of the most promising antigens for immunotherapy of chronic myelogenous leukemia (CML) include the specific fusion-protein, Bcr/AbI, and the overexpressed proteins WT1 and Proteinase 3. The clinical significance of Proteinase 3 as a target in myelogenous leukemias has been bolstered by detection of high frequencies of cytotoxic CD8+ lymphocytes specific for this antigen in patients undergoing immune therapies."

"Our investigation aimed to directly identify MHC-ligands derived from these antigens and presented on CML blasts by means of affinity-purification and mass spectrometric peptide-sequencing. Although no known or potential new epitopes were discovered for Bcr/AbI or WT1, a novel peptide from Proteinase 3 was detected among the more abundant MHC-ligands. Additionally, MHC-ligands derived from known immunogenic proteins overexpressed as a result of Bcr/AbI transformation were also identified," wrote A.J. Knights and colleagues, University of Spital Zurich.

"Our investigation is the second of only a small number of studies to identify a peptide from Proteinase 3 among the more abundant MHC-associated peptides and thus implies that peptides from this antigen are among the more abundantly presented of the known leukemic antigens," they reported.

The researchers concluded: "Taken in conjunction with clinical observations of functional Proteinase 3 specific CTL in patients', these data further support the application of this antigen as an immuno-therapeutical target for myelogenous leukemias."

Knights and colleagues published their study in Leukemia (A novel MHC-associated Proteinase 3 peptide isolated from primary chronic myeloid leukemia cells further supports the significance of this antigen for the immunotherapy of myeloid leukemias. Leukemia, 2006;20(6):1067-1072).

For additional information, contact A.J. Knights, University of Spital Zurich, Klin & Poliklin Onkol, Frauenklin Str 10, Nord 1, C102A, CH-8091 Zurich, Switzerland.

Publisher contact information for the journal Leukemia is: Nature Publishing Group, Macmillan Building, 4 Crinan St., London N1 9XW, England.

Keywords: Zurich, Switzerland, Biological Therapy, Chronic Myelogenous Leukemia, Immunology, Immunotherapy, Leukemia, Peptide Sequencing & mhc Ligands, Proteinase 3.

This article was prepared by Clinical Oncology Week editors from staff and other reports. Copyright 2006, Clinical Oncology Week via NewsRx.com.