Figure 1. Construction of the BLTS humanized mouse model.
In Step I, NSG mice are myoablated via γ irradiation (200 rads) using a Cesium-137 irradiator. In Step II, fetal tissues (spleen, thymus, and liver) are processed into 1 mm2 pieces and transplanted as a “sandwich” under the kidney capsule in irradiated NSG mice, following the administration of antibiotic and analogesic therapy and the induction of general anesthesia. In Step III, autologous CD34+ hematopoietic stem cells are isolated from the fetal liver via magnetic selection and transplanted at 2 × 105 cells per mouse via retro-orbital injection following kidney capsule transplantation of the lymphoid tissues. In Step IV, transplanted NSG mice were maintained under specific pathogen free conditions, and the human spleen and thymus organoids — along with other lymphoid tissues and associated immune cells — were allowed to develop over a period of 10 weeks, resulting in the BLTS humanized mouse model.