Comparative attachment of FITC–HHV-8 to PBMC subpopulations (B, T, monocyte, and NK), primary MVDECs, and the 293 epithelial cell line.

(A) HHV-8 histograms. Binding of FITC HHV-8 to PBMCs isolated from leukopaks of 2 distinct donors (right and left histograms) was assessed by flow cytometry. The top 4 histograms compare binding of FITC-virus (block) with FITC-avidin (control) (line) on normal B-cell, T-cell, monocyte/macrophage, and NK-cell populations identified by prior staining of the PBMCs with PE-conjugated monospecific antibodies as described in the text. The bottom left panel demonstrates staining of 293 cells performed and analyzed at the same time as the leukopak on the left, and the bottom right panel shows staining of fMVDECs at the same time as the leukopak on the right. (B) EBV histograms. Binding of purified EBV to a B-lymphoblastoid cell line (JY) compared with fMVDEC displays a pattern distinct from HHV-8. Virus was detected by indirect immunofluorescence (“Materials and methods”) and analyzed by flow cytometry.