HCMV IE and pp65 expression in macrophages derived from infected CD34⁺ progenitors 28 days postinfection. Cells were counterstained with Methylene Green. (A and B) Cells incubated with MoAb directed against IE protein. (E through H) Cells incubated with MoAb directed against pp65. (A and E) Macrophages derived from CD34⁺ cells infected with 95(2). (B and F ) Macrophages derived from CD34⁺ cells infected with Towne/lox². (C and G) Macrophages derived from mock/infected CD34⁺ cells. (D and H) HCMV-infected HEL cells, as a positive control. Original magnification × 400.