Immunophenotypic characterization of humanized MISTRG mice engrafted with CD34+CD38+hematopoietic stem cells

ZHOU Changyuan; YE Meilin; TAN Qinglong; LUO Ming; JIA Wenyu; LAI Ge'na; ZENG Xing

doi:10.13431/j.cnki.immunol.j.20190060

Abstract：This study was performed to investigate the differentiation and immunophenotypic characterization of purified lineage CD34+CD38+cord blood hematopoietic stem cells (HSCs) in MISTRG mice. Mononuclear cells were isolated from the whole blood via ficoll density gradient method and then CD34+HSCs were separated through magnetic activated cell sorting kit. The cell surface phenotype of culture-expanded CD34+HSCs was analyzed by multiparameter flow cytometry and the purity of CD34+CD38+HSCs was above 92.0％. Those cultured CD34+cells (2×105) were then injected into the liver of newborn MISTRG mice, and then the blood samples were collected at 3, 6, 9 and 12 weeks after the injection. After cell transplantation, the initial level of hCD45+cells was above 10.0％.The human T (hCD3+CD45+), B (hCD3-CD19+) and NK (hCD3-CD56+) cells were both detected, and the B (hCD3-CD19+) cells were present with highest abundance (the initial level was 49.0％±7.4％). Meanwhile, the human myeloid lineage cell population was mainly composed of macrophages (hCD14+CD68+, the initial level was82.3％ ± 4.5％). The percent of B (hCD3-CD19+) cells and macrophages increased gradually over time, while hCD45+, T (hCD3+CD45+) and NK (hCD3-CD56+) cellsdecreased gradually, especially NK (hCD3-CD56+) cells disappeared completely. In conclusion, the purified lineage CD34+CD38+cord blood HSCs can effectively differentiate into both lymphocyte and myeloid lineage cells in MISTRG mice. The percent of hCD45+cells decrease gradually within 12 weeks and the optimal humanization time is between 3 and 6 weeks.