The preparation of hl-60 cells vaccine expressing BCG heat shock protein 70 and detection of its immunogenicity in vitro

Abstract

Gene-modified cell vaccines are the best way to achieve the immunotherapy for all types of acute leukemia. In this study, the recombinant eukaryotic expression vector (pDisplay-HSP 70) of heat shock protein 70 (HSP 70) of Bacille Calmette- Guerin (BCG) was constructed by amplifying the whole BCG HSP 70 gene using polymerase chain reaction (PC R) and subcloning into the polyclone endonuclease sites in pDisplay. Then the HL-60 cell vaccine expressing the protein onto the cell surface was prepared by lipofectamine transfection and its anti-tumor effect and mechanism were further studied. Results showed that the fragment of BCG HSP 70 was consistent with Mycobacterium tuberculosis HSP 70 gene published in GeneBank. DNA sequencing showed that the recombinant vector was correctly constructed and named pDisplay- HSP 70. After BCG HSP 70 gene transfection, the yellow-green fluorescence on the HL-60 cells surface was observed under a fluorescence microscope. The immunogenicity of HSP 70-transfected HL-60 cells exhibited upregulated proliferation of lymphocytes, increased cytokine secretion (IFN-?) and enhanced killing activity. These results suggested that gene transfection of BCG HSP 70 could significantly enhance the immunogenicity of HL-60 cells. It may be used as a suitable candidate gene-modified cell vaccine for cancer immunotherapy. © 2012 Landes Bioscience.