Figure 3. Long-term effects of lethal irradiation and BM transplantation on normal monocyte-derived cell density and phenotype in ocular tissues.

Donor GFP⁺ cell densities in the iris and choroid of Cx ₃ cr1 ^+/gfp → WT BALB/c chimeric mice 6 months after BM reconstitution (A). There were significantly higher numbers of GFP⁺ cells in all uveal tract tissues of 6 month old chimeric mice (Cx ₃ cr1 ^+/gfp → WT) compared to 8 week old (8wks) and 36 week old (36 wks) non-irradiated naïve Cx ₃ cr1 ^+/gfp mice (A). * P < 0.05, *** P < 0.0005. Confocal microscopic images of retinal whole mounts from 6 month old BALB/c (B–D, H–J) and C57BL/6J (E–G, K–M) Cx ₃ cr1 ^+/gfp → WT chimeric mice. Donor GFP⁺ cells migrating into the BALB/c retina from the optic disc region (B; OD) and at the retinal periphery (C; broken white line indicates border between peripheral retina and ciliary body). Host derived GFP^- CD11b⁺ microglia were present throughout the OPL of the retinal parenchyma (D). GFP⁺ cells replenishing retinal tissue of C57BL/6J chimeric mice at the optic disc region (E) and periphery (F; broken white line indicates border between peripheral retina and ciliary body). Donor-derived GFP⁺ microglia in the OPL of C57BL/6J chimeric mice (G). Perivascular GFP⁺ cells at the optic disc region expressed MHC Class II in BALB/c (H; red) and C57BL/6J (K; red) chimeric mice. A population of GFP⁺ cells entering the retina at the periphery were MHC Class II⁺ in BALB/c (I; red) and C57BL/6J (L; red) chimeric mice. I, L; arrows point towards ciliary body at the retinal periphery. A subpopulation of GFP⁺ vitreal hyalocytes were MHC Class II⁺ in BALB/c (J) and C57BL/6J (M) chimeric mice. n= 6 mice per group. CB, ciliary body; OPL, outer plexiform layer.