**Monocyte-derived macrophages contribute to the neuroprotective and antiinflammatory retinal milieu.** (a) Changes in mRNA transcript levels of a series of cytokines in injured compared with noninjured retinas, as a function of time after the insult. (b) Changes in the mRNA transcript levels of various cytokines after MC-21 treatment, compared with injured untreated (left) and noninjured (right) retina. (c) Changes in mRNA levels of additional factors in the injured retina at day 2 after injury, with and without MC-21 treatment, presented relative to noninjured retina. (d) Changes in mRNA transcript levels of *cntf* at day 2 after injury, after MC-21 treatment, presented relative to noninjured retina. In a–d, a fold change of 1 indicates no change relative to the relevant control. The numbers situated above 1 indicate a fold increase, whereas the numbers below 1 indicate a fold decrease (values presented on a logarithmic scale). For all experiments, *n* = 3–6 per group, per time point. Data shown are representative of one to two independent experiments. Asterisks above bars represent statistical significance compared with the relevant control. In c and d, asterisks between bars represent statistical significance with respect to the MC-21 treatment. (e) Representative micrographs of retinas from day 2 after injury, showing the expression of TGF-β (red, left) and IL-10 (red, right) by activated IB-4^{+} myeloid cells (green; bar, 50 µm). Insets show higher magnification of representative double-labeled cells (bar, 5 µm). (f) Representative micrographs of retinas from [*Cx*_{3}cr1^{GFP/+} > WT] BM chimeras on day 2 after injury, showing the expression of TGF-β (red, left) and IL-10 (red, right) by infiltrating GFP^{+} monocyte-derived macrophages (green; bar, 50 µm). Insets show higher magnification of representative double-labeled cells (bar, 5 µm). (g and h) Representative micrographs of Fluoro-Gold–labeled retinas (blue; bar, 50 µm) from noninjured and injured mice without monocyte transfer and from injured mice adoptively transferred with WT, IL-10–deficient, or MHC-II–deficient monocytes. Bar graph shows quantification of RGC loss in the various groups. *n* = 4–6 per group. Data are presented as percentage of RGC loss relative to noninjured retina. Bar graphs throughout figure show mean ± SE of each group. *, P < 0.05; **, P < 0.01; ***, P < 0.001.

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