Complete internalization of large foreign particles by granulocytes.

<p>Hemocytes (average size 20.1 µm, n = 30) from the Stag Beetle <i>Lucanus maculifemoratus</i> (<i>Coleoptera</i>: Lucanidae) were injected into the hemocoel. At 12 h post injection, highly polymorphic glittering vacuoles were generated in the granulocytes. (A through C) The granulocytes engulfed and phagocytosed foreign cells and showed classic structures of phagocytosis (cell-in-cell invasion; a crescent-shaped nuclei) indicated by white arrow. (D through D2) Analysis by confocal microscopy demonstrated a complete internalization of hemocytes from <i>L</i>. <i>maculifemoratus</i> within the granulocytes. In some cases, one, or two, even three foreign hemocytes were phagocytized by the granulocytes (E through E2). D1, D2, E1, and E2 indicate a higher magnification of regions in inset of panel D and E. (F through H) GFP CellTracker dye labeled hemocytes (indicated by white arrow) from <i>L</i>. <i>maculifemoratus</i> were completely internalized by the granulocytes. GR, granulocytes; N, nuclei, Scale bar = 20 µm.