Figure 1

Changes to cell-shape and cytoskeleton organisation of CLL lymphocytes within high-density culture (fixed cells stained for NBD-phallacidin to show F-actin dependent cell-shape were assessed using imaging flow cytometry:). Panel A. Images of cells fixed in whole blood directly from the circulation, using a case where >95% of cells were CLL B-lymphocytes. Imaging is restricted to nucleated cells (identified by Dapi fluorescence), and neutrophils and monocytes are excluded by size and shape criteria. The cells demonstrate largely spherical shape and uniform F-actin distribution [confirmed by high aspect ratio: mean 0.84 ± 0.01 where a perfect sphere is 1.0]. Panel B. Cell shape from high-density culture: profiles indicate irregular and round cells [overall mean aspect ratio is reduced indicating greater irregularity than circulating cells: 0.69 ± 0.01 (p < 0.00001, n = 560 Mann-Witney U test)]. Cells with polarised F-actin form 46% of cells compared with 4% of cells from circulation (representative of 8 separate experiments using adherent or non-adherent cells).