HCMV infection of megakaryocytes generated in cultures of CD34⁺ cells challenged with HCMV.

Before initiation of the culture, HCMV was used to infect CD34⁺ cells that subsequently were allowed to mature to megakaryocytes in the presence of thrombopoietin (TPO). At the end of the culture, HCMV-infected and mock-infected cells (derived from TPO-supplemented cultures) were purified using magnetic beads based on the expression of CD42a antigen after 12 days of culture. Cells were counterstained with DAPI blue nuclear staining and photographed at ×600 magnification. (A) Mock-infected cells stained with fluorescein isothiocyanate (FITC)-conjugated CD42a. (B) Mock-infected cells stained with hematoxylin. (C) HCMV-infected cells stained with CD42a-FITC. (D) Mock-infected cells stained with isotype control antibodies (see “Material and Methods”). (E) HCMV-infected cells stained with biotinylated anti-HCMV pp65 and streptavidin-PE. (F) HCMV-infected cells stained with CD42a-FITC, biotinylated anti-IE mAb, and streptavidin-PE.