CD4 and infection: At 1 week after implantation, the infection-only control defects had significantly increased numbers of total cells (Fig. 5A), CD3+ T cells (Fig. 5B), CD3+CD4+ helper T cells (Fig. 5C), CD3+CD8+ cytotoxic T cells (Fig. 5D), CD11b+ myeloid cells (Fig. 5I), Ly6G+ neutrophils (Fig. 5J), and Ly6Chigh classical inflammatory monocytes (Fig. 5L) compared to lysostaphin-delivering hydrogel–treated infections and both sterile control groups.