Induction of CTL by immunization of bcr-abl fusion gene

AIM To investigate the effect of bcr abl gene immunization on the chronic myelogenous leukemia (CML) and explore the feasibility of this fusion gene immunization in CML gene therapy. METHODS Two primers were designed for the amplication of a 490 bp bcr abl cDNA coding sequence by PCR. After the PCR product was confirmed by the sequence analysis, it was inserted into the expression vector pcDNA3.1, which was instantly expressed in p815 cells by means of electroporation. The stable expression cell colonies were obtained as a target cells after the G418 selection. We also used the recombinant expression vector to immunize the BALB/c mice to get effector cells. The cytotoxicity of CTL was detected with LDH assay. RESULTS ① A 490 bp bcr abl cDNA was amplified by PCR, and sequence analysis showed the whole correct sequence except base C mutated for T in position 452. ② A recombinant expression vector, named pcDNA/ bcr abl was constructed. ③ The bcr abl positive, expression stable p815 cells were obtained by G418 selection, and RT PCR examination showed that bcr abl had been transcribed in all positive cell clones. ④ LDH assay showed CTL was induced by the bcr abl immunization. CONCLUSION Fragement of 490 bp bcr abl gene immunization was capable of inducing specific CTL to kill the target cells that have expressed the bcr abl fusion gene.