Ex vivo expansion of human cord blood CD133⁺ cells by anti-LILRB2 monoclonal antibody in NSG mice as determined by NSG transplantation. (A) After 10 days culture in STF medium with or without same amounts of coated (25 µg/mL in 250 µL PBS) or soluble (5 µg/mL in 250 µL StemSpan media) anti-LILRB2 mAb, 1 × 10⁴ input equivalent human cord blood CD133⁺ cells were transplanted into NSG mice. Engraftment of human CD45⁺ in peripheral blood at 3 and 7 weeks are shown. *P < .05; n = 4. (B) Engraftments of human CD45/CD71⁺ in bone marrow of mice described in panel A at 8 weeks; n = 4. (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. (D-F) Summary of multilineage contributions based on data shown in panel C; n = 4. (G) Engraftment of human CD45⁺ cells in peripheral blood of secondarily transplanted mice at 3, 7, 10, and 30 weeks. *P < .05; n = 3. (H) Engraftment of human cells in bone marrow of secondarily transplanted mice at 30 weeks; 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 based on data from panel I. *P < .05; n = 3. Ctrl, control; n.s., not significant.