Ex vivo expansion of human cord blood CD133⁺ cells by anti-LILRB2 pAb as determined by NSG transplantation. (A) After 10 days of culture in STF medium with or without same amounts of coated (25 µg/mL in 50 µL PBS) or soluble (5 µg/mL in 250 µL StemSpan media) anti-LILRB2 pAb, expansion of 1 × 10⁴ input equivalent human cord blood CD133⁺ cells were transplanted into NSG mice (n = 8). Engraftment of human cells (human CD45⁺) in peripheral blood at indicated weeks are shown***P < .001. (B) Engraftment of human CD45/CD71⁺ in bone marrow of mice described in panel A at 36 weeks. *P < .05; n = 8. (C) Multilineage contribution of cultured human umbilical cord blood CD133⁺ cells. Shown are representative flow cytometric profiles of bone marrow cells from 1 primary transplanted mouse of each group. Myeloid, CD45/CD71⁺CD15/CD66b⁺; lymphoid, CD19/CD20⁺; hematopoietic stem/progenitor cells, CD19/CD20⁻CD34⁺. (D-F) Summary of multilineage contributions from data shown in panel C. *P < .05; **P < .01; n = 8. (G) Engraftment of human CD45⁺ cells in peripheral blood of secondarily transplanted mice at 3 and 7 weeks posttransplant are shown. **P < .01; n = 3. (H) Engraftments of human cells in bone marrow of secondarily transplanted mice at 8 weeks posttransplant are shown. *P < .05; n = 3. (I) Representative flow cytometric profiles showing multilineage contribution of human umbilical cord blood CD133⁺ cells in the bone marrow of secondarily transplanted mice at 8 weeks posttransplant. (J-L) Summary of multilineage contributions from data shown in panel I. *P < .05; n = 3. Ctrl, control; n.s., not significant.