Aim: To investigate the potential of human growth hormone (hGH) to improve human hematopoietic reconstitution in humanized mice. Materials & methods: Immunodeficient mice were conditioned by total body irradiation and transplanted with human CD34+ fetal liver cells. Peripheral blood, spleen and bone marrow were harvested, and levels of human lymphohematopoietic cells were determined by flow cytometry. Results: Supplementation with hGH elevated human lymphohematopoietic chimerism by more than twofold. Treatment with hGH resulted in significantly increased reconstitution of human B cells and myeloid cells in lymphoid organs, enhanced human erythropoiesis in the bone morrow, and improved engraftment of human hematopoietic stem cells. Conclusion: hGH supplementation promotes human lymphohematopoietic reconstitution in humanized mice.
Keywords: B cells; erythropoiesis; growth hormone; hematopoietic stem cell; humanized mouse; immunodeficient mouse; myeloid cells; transplantation.
Humanized mice generated by human hematopoietic stem cell transplantation play crucial roles in biomedical investigations. One of the factors hindering the efficacy of their construction is the lack of or insufficient interaction of human cells to mouse cytokines and growth hormones (GHs) that are crucial for hematopoiesis and immune cell differentiation. In this study, we show that injection of human GH significantly improved human hematopoietic stem cell engraftment and function, as well as immune cell reconstitution in humanized mice. Our findings indicate that human cells may not efficiently respond to mouse GH, and generation of immunodeficient mice producing human GH may improve the efficacy of humanized mouse construction.