Fig. 4. Redistribution of HP1 in peripheral blood lymphocytes (PBLs). (A) Double staining with anti-HP1 (green) and anti-HP1 (red) antibodies. The panel shows non-treated (NT), phytohemagglutinin-treated (PHA), lipopolysaccharide-treated (LPS) and IL-2-treated (+IL-2) human PBLs. Bar, 13 µm. Note the difference in the size of the nucleus. (B) Morphometric data showing the percentage of HP1 and HP1 foci in the nucleus of non-treated and treated cells, as indicated (dark blue bars: 1-2 µm foci; green bars: 2-3 µm foci, orange bars: 3-4 µm foci, and light blue bars: 4-5 µm foci). Optical sections and `projections' of 15 different cells were analyzed in each case. (C) Fold-difference in the abundance of the various classes of HP1 particles upon treatment in relation to controls. The results, shown in a tabular form, were derived from the data presented in B. (D) Western blots of PBLs before and after treatment with LPS or IL-2. The blots were probed for HP1, HP1 and histone H3, as indicated.