CLP was performed in male WT and Fgl2KO C57BL/6 mice according to the protocol reported (9). Ligation of the cecum at designated positions was the major determinant of sepsis severity. The intermediate sepsis was ligated at half the distance between distal pole and the base of cecum (moderate CLP), while severe CLP sepsis comprised ligation of 75% of the cecum. A through-and-through cecal puncture was performed with a 21-gauge needle followed by an additional puncture in the distal tip of the cecum. At indicated intervals, rectal temperature was measured. Peritoneal exudates and blood were collected for respective experiments. Blood bacteria levels were determined by growth on tryptic soy agar plates. Immunohistochemical staining for H&E, CD45 (1:100, catalog no. sc-53665, Santa Cruz Biotechnologies), and F4/80 (1:100, catalog no. 123105, BioLegend) was performed with the cecal tissues from WT and Fgl2KO mice after being challenged with CLP for 24 hours. For the abscess formation experiments, mice were sacrificed at day 7 after CLP.