Influence of the heparin affinity of dead cells on phagocytosis.
Live or dead Jurkat cells labeled with TAMRA (JurkatT) were incubated with human monocyte–derived macrophages (MDMs) cultured on Permanox slides. Analysis of the monolayers for the population of cells that were positive for FITC–anti-CD14 and for TAMRA was carried out by laser scanning cytometry and confocal microscopy. (upper panels) Results obtained by laser scanning cytometry in experiments carried out in the absence of JurkatT cells (A), in the presence of live JurkatT cells (B), and in the presence of dead JurkatT cells incubated without additions (C) or together with unlabeled annexin V (D), pentosan polysulfate (E), or a combination of annexin V and pentosan polysulfate (F). (lower panels) Phagocytosis of JurkatT under these experimental conditions by confocal microscopy. (top line, left to right) MDMs stained with FITC–anti-CD14 (green), live and dead JurkatT cells, respectively, labeled with TAMRA (red). (lower 6 panels) Series of sections taken through MDM after engulfment of a dead JurkatT cell. The depth of each section is marked in italics (objective, ×60; zoom factor, 5.0).
