Figure 3.

Binding of PGRP-LC to a Gram-Positive Bacterium and a Gram-Positive Bacillus Ex Vivo

The GFP-tagged transmembrane PGRP-LCx (GFP-PGRP-LCx, expressed in macrophages) was assessed by fluorescence imaging for binding to S. aureus (Ai–Ei), S. aureusTagO (Aii–Eii), B. subtilis (Aiii–Eiii), and B. subtilisTagO (Aiv–Eiv), respectively. (Ai–Aiv) GFP-PGRP-LCx-expressing hemocytes were mixed with bacteria. (Bi–Biv) Bacteria were pre-stained and identified by DAPI. (Ci)–(Civ) presents corresponding DIC images in which the extent of macrophages is indicated by the dashed outlines. (Di–Div) Dashed squared regions (82 μm) indicated in (A)–(C) are shown as a dual color overlay of GFP (PGRP-LC) and DAPI (bacteria) signals. (Ei–Eiv) Plots of fluorescence intensity along the dashed lines in (Di–Div) (15 μm transect) are shown highlighting the overlap of the extracellular signals between GFP and DAPI.