Establishment of recombinant Mycobacterium smegmatis secreting IL-2 / 第三军医大学学报

ABSTRACT

Objective To establish a recombinant Mycobacterium (M.) smegmatis secreting interliukin-2 (IL-2) for the prevention and treatment of human bladder cancer. Methods The M. tuberculosis HSP70 promotor, ?-antigen signal peptide gene, and human IL-2 cDNA were amplified from plasmid pY6013, pIJK-1, and pHIG53 respectively by PCR. The products were cloned into plasmid pRR3 to construct a mycobacterial shuttle-expressing plasmid pR-a-IL-2 secreting human IL-2. After confirming the construction was correct by enzyme digestion, plasmid pR-?-IL-2 was transduced into M. smegmatis mc 2 155 by electroporation. The stability of the recombinant mycobacteria was evaluated and the activity of IL-2 secreted by the bacteria was assayed. Results Structure of the pR-a-IL-2 was correct and it was effectively transduced into M. smegatis mc 2 155. The recombinant mycobacteria stably expressed IL-2. The IL-2 activity in the medium was 118.5 U/ml. Conclusion The successful establishment of recombinant M. smegmatis can provide the basis for the research of biotherapy and prevention of the recurrence of bladder cancer.