S100A8 and bacterial infectious disease: In A/J mice treated with wild type LeTx, these included S100a8, S100a9, Fcgr3 and Cxcl1. Additionally, Plaur, which encodes CD87/uPAR, a receptor that has been shown to be critical for neutrophil recruitment in vitro [44] and for neutrophil recruitment into mouse lungs in vivo in bacterial infection models [45,46], was down-regulated in LeTx-treated A/J lungs.