Enhancement of specific cellular immune response induced by DNA vaccines encoding PML-RARalpha and hIL-2 genes

Abstract

A DNA vaccine encoding PML-RAR alpha fusion gene is thought to be a promising approach for acute promyelocytic leukemia patients to enhance immune responses after attaining complete remission. In this study, we sought to enhance cellular immunity by coexpressing human interleukin (hIL)-2 genes. Successfully constructed plasmids PML-RAR alpha-hIL-2-pIRES, PML-RAR alpha-pIRES and hIL-2-pIRES were delivered intramuscularly in BALB/C mice at 14-day intervals for three cycles. The cellular immune responses with respect to the specific cytotoxicity of spleen cells; interferon-gamma secretion in sera, and the T-cell receptor rearrangement excision circles of thymocyte were significantly increased from PML-RARalpha-hIL-2-pIRES immunized mice. Our results indicate that a DNA vaccine with PML fusion gene segment and hIL-2 together might elicit increased cellular immune responses in mice.