In vitro induction of p210~(Bcr-Abl) protein-specific cytotoxic T cell responses using 562 cell total RNA transfected human dendritic cells / 中国输血杂志

ABSTRACT

Objective To investigate whether human monocyte-derived dendritic cells (DCs) can express p210 Bcr-Abl protein and induce antigen-specific CTL responses in vitro after transfection with total RNA of K562 cells (K562-RNA).Methods Immature DCs were derived from human peripheral blood monocytes after 5 day incubation in the presence of GM-CSF and IL-4. The cells were then transfected with K562-RNA using electroporation or DOTAP lipofection. To verify the successful transfection of DCs with K562-RNA, Bcr-Abl fusion gene expression was determined by RT-PCR and Western blot. The immune phenotypes of the DCs were analyzed by flow cytometry. CTL cytotoxicity was assayed by propidium iodide (PI) stain and flow cytometry. The amount of DCs, CD1a expression and purity of DCs were measured by FACS.Results Bcr-Abl fusion gene appeared in the DCs after transfection with K562 cell total RNA. But 24 hours later, the Bcr-Abl mRNA from the K562-RNA transfected DCs disappeared, while the cells were expressing p210 Bcr-Abl protein. The transfected DCs could significantly promote T lymphocytes to kill the target K562 cells. We found that PBMC can be induced to DC in culture medium containing human plasma, suggesting a potential for clinical application.Conclusion Human dendritic cells transfected by K562 total RNA can induce effective p210 Bcr-Abl protein-specific immune responses, which might broaden the spectrum of possible DC-based clinical applications.