Streptamer-based selection of WT1-specific CD8+ T cells for specific donor lymphocyte infusions
Received 26 December 2009; received in revised form 2 July 2010; accepted 6 July 2010. published online 16 July 2010. Uncorrected Proof
Objective
Donor lymphocyte infusions may generate a desirable graft-versus-leukemia effect, but also elicit a noxious graft-versus-host disease. A positive selection of leukemia (antigen)-specific T cells would be highly desirable. In this study, we focused on the immunogenic leukemia antigen Wilms’ Tumor gene 1 (WT1).
Materials and Methods
We employed the technology of streptamers available at good manufacturing practice level to first determine the frequency of human leukocyte antigen−A2 restricted WT1-specific CD8+ T cells. Then, specific cells were labeled with streptamers and selected by magnetic cell separation. Purity and immunophenotype of selected cells were analyzed.
Results
Twenty-one of 40 healthy donors had naïve WT1-specific CD8+ T-cell frequencies of >0.5%, and 8 of 40 even >1.0% of all CD8+ T cells. In 7 of 10 acute myeloid leukemia patients, the frequencies were 0.5% to 3.65%. After positive selection by magnetic cell separation, a 60-fold increase with a purity of up to 17.79% in the lymphocyte gate and 86.18% in the CD8+ T-cell gate could be achieved for CD8+WT1streptamer+CD28+/−CD45RA+CCR7− effector T cells.
Conclusions
Streptamer technology allows selection of pure WT1-specific effector T cells. This is a prerequisite for clinical applications targeting tumor-specific antigens, such as adoptive T-cell transfer.
aDepartment of Internal Medicine III, University of Rostock, Rostock, Germany
bDepartment of Hematology and Oncology, Zhongda Hospital, Southeast University Medical School, Nanjing, P.R. China
cDepartment of Oncology, The Fourth Center Clinical College of Tianjin Medical University, Tianjin, P.R. China
dDepartment of Immunology, Jiangsu University, Zhenjiang, P.R. China
eDepartment of Surgery, University of Rostock, Rostock, Germany
Offprint requests to: Michael Schmitt, M.D., Ph.D., Clinical Stem Cell Transplantation and Immunotherapy, Department of Internal Medicine III, University of Rostock, Ernst-Heydemann-Str. 6, Rostock 18055, Germany
ABSTRACT