Figure 2. Immunophenotyping of uterine macrophages 24 hours after withdrawal of progesterone.

GFP⁺ cell populations present in the uterus were characterised by flow cytometry of tissue digested from both control (non-stimulated/non-decidualized) and decidualized horns. (A) In MacGreen mice, few GFP⁺ cells were detected in non-stimulated uterine horns (non), which was in marked contrast to the abundant GFP⁺ cells in the decidualized horn (stim). (B) Analysis of proportion of influxing cells revealed a significant increase in GFP⁺ cell populations (p < 0.001) in stimulated uterine horns (n = 7). GFP⁺ cells (see A) were gated for further analysis and expression of F4/80 and Gr-1 was assessed. (C) The majority of GFP⁺ cells were F4/80⁺ and almost all expressed Gr-1. Isolated GFP⁺ cells had mononuclear morphology as determined by immunofluorescence (green; GFP, blue; DAPI). (D) F4/80 expression within the GFP⁺ cell population was detected in the majority of cells (n = 5, p < 0.01). (E) F4/80 and Gr-1 expression in non- and stimulated horns in wildtype (WT) mice was assessed. (F) In WT mice Gr-1⁺ cells were significantly increased in stimulated compared to control horns (n = 4–6, p < 0.01). (G) F4/80⁺ Gr-1⁻ populations were unchanged in non and stimulated uterine horns but the proportion of total F4/80⁺ cells was increased in stimulated compared to control horns (n = 5–6, p < 0.01). (H) The majority of influxing Gr-1⁺ cells were F4/80⁺ (n = 5, p < 0.01).