IL-4c and Thio+IL-4c induces alternatively activated macrophages with distinct phenotypes. Mice were untreated (naïve/resident) or injected i.p. with IL-4c alone (IL-4c) or thioglycollate alone (Thio) or Thio and IL-4c (Thio+IL-4c) on day 0 and then with IL-4c again (for IL-4c and Thio+IL-4c) on day 2, and PEC was analyzed on day 4. (A) Representative FACS plots shows EdU incorporation by peritoneal macrophages after treatment. EdU was injected 3 hours before analysis. (B) Quantification of EdU incorporation in macrophages. Results are representative of 3 independent experiments. (C) RNA of peritoneal macrophages was isolated for RT-PCR analysis for expression of Chi3l3, Arg1, Retnla, and Raldh2 and normalized to expression of GAPDH. Graphs depict mean ± standard error of the mean of individual mice pooled from 5 to 6 independent experiments. (D) EdU incorporation by peritoneal macrophages after injection of wild-type Stat6^+/+ mice or Stat6^−/− mice with IL-4c alone, Thio, or Thio+IL-4c. (E) Quantification of EdU incorporation in macrophages. (F) Total number of F4/80⁺ macrophages recovered. Results shown are representative of 2 separate experiments. (G) Representative FACS plots gated on CD11b⁺ cells for CX3CR1^GFP/+ reporter mice treated as above. (H) The median fluorescent intensity (MFI) of GFP, gated on CD11b⁺ cells from the peritoneal cavity of individual mice. Data are representative of 3 independent experiments. *P < .05 and **P < .01 as determined by ANOVA.