c-IAP1 redistribution is a differentiation-associated event in various cell types. (A) Fluorescence microscopy analysis of c-IAP1 (mAb; Pharmingen) in peripheral blood CD34⁺ cells and monocytes (Mo) obtained from healthy donors and in macrophages (MΦ) and dendritic cells (DC) obtained from monocytes cultured for 6 days in the presence of M-CSF or GM-CSF/IL-4, respectively. The top panels show c-IAP1 alone (green); the bottom panels, c-IAP1 (green) + Hoechst 33352-labeled nuclei (blue). (B) Fluorescence microscopy analysis of c-IAP1 (mAb; Pharmingen; green) in CD34⁺ cell-derived erythoblasts (Ery) and megakaryocytes (Meg). Nuclei were labeled simultaneously with Hoechst 33352. (C) Colocalization of Golgin 97 (green) and c-IAP1 (red) in macrophages derived from peripheral blood monocytes as described for panel A. (D) Fluorescence microscopy analysis of c-IAP1 (pAb; Santa Cruz Biotechnology) in HT29 cells studied before (control) and after (confluent) reaching confluence in culture and in a methotrexate-resistant, well-differentiated derivative cell clone (HT29-MTX). (E) Fluorescence microscopy analysis of c-IAP1 (pAb; Santa Cruz Biotechnology) in control (Co), Bcl-2-overexpressing (Bcl-2), and TPA-resistant U937 cells exposed for 72 hours to 20 nM TPA. (F) May-Grünwald-Giemsa staining (MGG) and fluorescence microscopy analysis of c-IAP1 (pAb; Santa Cruz Biotechnology; Bcl-2) in bone marrow monocytes from control (Co) and Bcl-2 transgenic (Bcl-2) mice, cultured for 3 days in the presence of CSF-1-containing medium. (G) Peripheral blood mononuclear cells obtained from patients with chronic myelomonocytic leukemia (CMML) were cultured for 6 days in the presence of M-CSF or GM-CSF/IL-4. The top panels show fluorescence microscopy analysis of c-IAP1; the bottom panels, flow cytometry analysis of CD71 and CD1a membrane expression. White histograms indicate CMML patient; and gray histograms, healthy donor. One representative of 7 studied patients is shown. Magnification: × 700 (A-C, E, G) and × 500 (D, F).