Neutrophil crosstalk drives macrophage aggregate formation.

<p>(A) Double transgenic <i>Tg(mpeg</i>:<i>dendra2)</i> x <i>Tg(mpx</i>:<i>mCherry)</i> larvae show that neutrophils are present in and around macrophage aggregates. Images at 40X; scale bar is 20 μm. (B) Representative 20X images of Rac2WT or Rac2D57N larvae at 24 hpi following inoculation. <i>Tg(mpx</i>:<i>mCherry-2a-rac2wt)</i> (Rac2WT) or <i>Tg(mpx</i>:<i>mCherry-2a-rac2d57n)</i> (Rac2D57N) were crossed to <i>Tg(mpeg1</i>:<i>dendra2)</i> and the resulting double transgenic larvae were infected with 50 CFU WT <i>S</i>. <i>iniae</i> or mock-infected with PBS. Rac2D57N larvae are defective for aggregate formation. Scale bar is 80 μm. (C) Quantification of the average total percent of larvae forming macrophage aggregates from (B).