Immunostaining of stromal marker-positive cells.

Immunostaining is shown for human-specific cell surface markers in stromal layers of chimeric bone marrow cultures (A-G) or cell suspensions (H,I,K) from NOD/SCID mouse bone marrow harvested 5 to 11 weeks after transplantation with human blood cells. Mice were transplanted with human CD34-enriched PBCs (A,B,D,H,I,J) or light-density CBCs (C,D,G). The antibodies used were directed to the following human cell surface antigens: (A) HLA class-I, (B) 5B5 (fibroblast), (C) vWF, (D,E) KDR/flk-1, (F) HLA class-I, (G) CD34, (H) HLA class-I, (I) AS02 (fibroblast), (K) HLA class-I. Positive staining appears as red or brown. Controls from bone marrow from nontransplanted mice were processed in parallel for all markers (F,K). (Original magnification, 40-fold [A], 400-fold [B-G], 1000-fold [H-K].)