Figure 2.

PCTR1 promotes Escherichia coli clearance during infection. A–E: Self-resolving inflammation was initiated by injecting E. coli [1 × 10⁵ colony forming units (c.f.u.), i.p.]. Twelve hours after infection, mice were given 30 ng PCTR1/mouse or vehicle control (saline alone, i.p.). A: Quantification of peritoneal macrophages (CD11b⁺ F4/80⁺ Ly6G⁻). B and C: Macrophage phagocytosis of E. coli measured by flow cytometry in the peritoneum (B) and spleen (C). D: Exudate E. coli levels were assessed 24 hours after inoculation. E: PMN cell counts in the peritoneum after E. coli infection. Dotted line represents the T_max. F: Planaria were surgically injured, kept in water with PCTR1 or vehicle control for 6 days. Dashed lines show the tissue regeneration index. Data are expressed as means ± SEM (A–F). n = 3 to 5 mice per time point (A–E); n = 12 planaria/group (F). *P ≤ 0.05, **P ≤ 0.01, and ***P ≤ 0.001, t-test, compared with E. coli alone; ^††P ≤ 0.01 compared with vehicle control; ^‡P ≤ 0.05, ^‡‡P ≤ 0.01 at 1 nmol/L PCTR1 compared with vehicle. PCTR, protectin conjugates in tissue regeneration; PMN, Polymorphonuclear leukocyte; R_i, time interval between T_max and T₅₀; T_max, point when PMN reach maximum; T₅₀, point when PMN numbers reach 50% of maximum; (TRI)_max, time to maximum tissue regeneration (Materials and Methods); TRI₅₀, time to 50% tissue regeneration.