Fig. 1. A distinct proliferative subset of Ly6C^hi monocytes emerges in the peripheral blood during bacterial infection and sepsis.

(A to C) Proliferative Ly6C^hi monocytes in the blood assessed by BrdU incorporation in vivo (A) and numbers quantified (B) or Fucci-474 mice (C) were administered E. coli or phosphate-buffered saline (PBS) intraperitoneally (i.p.) for 9 hours. Numbers in fluorescence-activated cell sorting (FACS) plots represent the percentage of positive cells. Results are expressed as means ± SD (n = 4) and representative of one of three experiments. ***P < 0.001 (Student’s t test). (D and E) Mice were subjected to CLP-induced sepsis, and proliferative Ly6C^hi monocytes in the blood were quantified on the basis of BrdU incorporation at indicated time points (D). Results are expressed as means ± SD (n = 5 per group) and representative of one of three experiments. **P < 0.01, and ****P < 0.0001 [one-way analysis of variance (ANOVA)] compared to day 0. (E) Overlay of surface markers of blood proliferative versus nonproliferative Ly6C^hi monocytes on day 12 of CLP-induced sepsis.