Examination of the ability to support AGM derived-hematopoiesis in an ALCAM-transfected endothelial cell line.

(A) E10.5-derived AGM cells were fractionated into CD34⁺c-Kit⁺ cells and further subdivided at the expression of ALCAM. Among CD34⁺c-Kit⁺ cells, 72.4% were CD45⁺ (data not shown). (B) A total of 1000 CD34⁺c-Kit⁺ALCAM⁺ cells were cultured with ALCAM-transfected GM2 cells or vector-transfected cells for 7 days. Nonadherent cell number was scored (Bi), and expression of c-Kit was examined by FACS (Bii). *P < .05. (C) Hematopoietic colony morphologies of CD34⁺c-Kit⁺ALCAM⁺ cells were cultured on vector-transfected cells (Ci) or ALCAM-transfected cells (Cii) for 7 days. (Ci) Macrophagelike cells that predominate in the culture (× 200). (Cii) Blastlike cells (× 200). (D) A total of 1000 CD34⁺c-Kit⁺ cells were cultured in the presence of ALCAM-Fc or control CD4-Fc for 7 days. Nonadherent cells were harvested, and the cell number was scored (Di). Expression of c-Kit was examined in each nonadherent cell by FACS (Dii). *P < .05.