FIG 4.

MDSCs and macrophages from Arg-1^fl/fl;Tie-2^Cre mice express limited arginase-1 in vivo. Catheter-associated infections were established in Arg-1^fl/fl;Tie-2^null (WT) and Arg-1^fl/fl;Tie-2^Cre mice following challenge with 10³ CFU of S. aureus LAC. Animals were sacrificed at days 7 and 14 postinfection, whereupon MDSCs (CD45⁺ Ly6G^high Ly6C⁺) and monocytes (CD45⁺ Ly6G⁻ Ly6C⁺) were isolated by FACS analysis for RT-qPCR quantification of Arg-1 and iNOS expression (A) and arginase activity assay (B). Results are representative of two independent experiments. **, P < 0.01; ***, P < 0.001 (unpaired 2-tailed Student's t test).