Improvement of human myeloid and natural killer cell development in humanized mice via hydrodynamic injection of transposon plasmids containing multiple human cytokine genes

Abstract Humanized mice reconstituted with a functional human immune system (HIS) are instrumental in studying human immunity and immune disorders in vivo . The poor or lack of cross‐reactivity between mouse cytokines and human cells limits the development and/or function of human immune cell subsets including human myeloid, natural killer and B cells. Here we explored the potential to achieve long‐term production of human cytokines in immunodeficient mice using a transposon‐plasmid–based hydrodynamic injection approach. We constructed a transposon‐plasmid carrying five human cytokine coding sequences (named PB‐5F), and observed that four of the cytokines (granulocyte–macrophage colony‐stimulating factor, interleukin (IL)‐15, IL‐6 and IL‐3) were detectable in sera and three (granulocyte–macrophage colony‐stimulating factor, IL‐15 and IL‐6) showed long‐term production in immunodeficient mice that received a single hydrodynamic injection of PB‐5F plus the transposase plasmid (Super PB). Furthermore, a single injection of PB‐5F/Super PB markedly enhanced the reconstitution of human myeloid cells and natural killer cells, and promoted human B‐cell maturation in HIS mice. Taken together, our data revealed that hydrodynamic injection of the PB‐5F/Super PB vectors may serve as a convenient and efficacious means to promote human immune function in HIS mice.