Dendritic Cells Tranfected with CML-28 cDNA Induce CML28-Specific Cytotoxic T Cells.

Dendritic cells (DC) are the most potent antigen-presenting cells known; the use of DC loaded with tumor antigen is one of the most promising approaches to induce specific immune response. CML28 is an attractive candidate. According to the published article and our following study, CML28 is a broadly immunogenic antigen, which is overexpessed in leukemia cells, including acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL) and chronic myelogenous leukemia (CML); but not in normal hematopoietic tissues or other normal tissue, with the exception of testis. In our study, DCs were generated from peripheral blood mononuclear cells (PBMC) by culture with GM-CSF, IL-4 and TNF-α. The full CML28 cDNA was amplified from K562 cell and then cloned into plasmid pcDNA3.1 HisA. Load DC with the constructed plasmid pcDNA3.1 HisA-CML28 by electroporation. The results of FACS analysis and Western Blot respectively demonstrate that the plasmid transfected DC retain immunophenotypical characteristics and can express the fusion protein CML28-His. Cytotoxic T lymphocytes (CTL) were generated from autologous PBMC stimulated by the transfected DCs. Cytoxicity assay in vitro revealed that CTL can recognize and lyse CML28-expressing target cells, such as the transfected DCs but not normal autologous DCs, which show that the plasmid pcDNA 3.1 HisA-CML28 transfected DC can induce CML28-specific CTL. Our studies demonstrate that CML28 can be a promising target of tumor antigen for leukemia-specific immunotherapy and DC loaded with CML28 tumor antigen can be a promising tool to induce specific anti-leukemia immune response.