Figure 10.

GFP⁺ macrophages could switch to an arginase⁺ phenotype after LPS-IL-4 treatment. Partial GFP BM-chimera mice were established on the C57BL/6 background and achieved an average of 60–80% engraftment. After 4 weeks adult (3 months) GFP BM-chimera mice were given an intraperitoneal injection of saline or LPS and 1 h later received an intracerebroventricular (icv) injection of vehicle or IL-4. Mice were perfused and fixed 24 h later. A, Representative images showing GFP (i), GFP/Arg (ii), and GFP/Arg/Iba-1 (iii) staining. Scale bars, 100 μm. White arrows indicate GFP⁺ or GFP⁺/Iba-1⁺ cells used for insets in ii, iv, and v, and white arrowheads indicate Arg⁺ colocalization with GFP⁺, Iba-1⁺, or GFP⁺/Iba1⁺ cells used for insets in ii, iv, and v. Scale bars, 25 μm. B, Number of GFP⁺ cells per section at the icv injection site and nearby choroid plexus (n = 4–5). C, Percentage Arg⁺ cells that were GFP⁺, Iba-1⁺, and GFP/Iba-1⁺ in the LPS-IL-4 group. Error bars represent the mean ± SEM. Means with *p < 0.04 are significantly different from Saline-Vehicle controls.