Interleukin-12 gene therapy vaccines: Directing the immune system against minimal residual leukemia

Current overall survival rates for patients with AML remain poor and there is need for novel therapeutic approaches. One such approach is to use the patient's own immune system to eliminate minimal residual disease. Recent advances in genetic manipulation of tumor cells, together with a better understanding of the immune mechanisms controlling the host-tumor relationship have led to a flurry of preclinical and clinical studies on tumor cell vaccines. Here we present a brief overview of genetic manipulation of tumor cells, and highlight important principles of cancer immunity and cancer vaccines. Special emphasis is given on recent work on the role of interleukin 12 (IL-12) based vaccines in murine AML. These studies have shown that vaccines with AML cells, genetically modified to secrete IL-12, are potent stimulators of the immune system and lead to the development of both prophylactic and therapeutic anti-leukemia immunity.