Dexamethasone Provides Effective Immunosuppression for Improved Survival of Retinal Organoids after Epiretinal Transplantation

Figure 7

Immune responses after transplantation. (a, b, d) Few activated microglia (CD68-positive) were seen in the healthy eye (transplanted with a retinal organoid, but receiving no immunosuppressive treatment), Oz-eye (eye with ocular hypertension (OHT) transplanted with a retinal organoid and treated with dexamethasone), and OHT-eye (OHT eye transplanted with a retinal organoid, but receiving no immunosuppressive treatment). (c) However, many CD68-positive cells were seen in the RAP-eye (OHT eye transplanted with a retinal organoid and treated with rapamycin). (e) In the healthy eye, few microglia (Iba1-positive) were spread out within the inner retina. (f) Few microglia (Iba1-positive) were seen clustered near the transplant site in the Oz-eye. In the (g) RAP-eye and the (h) OHT-eye, large numbers of microglia (Iba1-positive) were found to be accumulated at the transplant sites. (i) GFAP- and (m) vimentin-positive Müller cells were distributed throughout the inner retina of the healthy eye. Similarly, (j) GFAP- and (n) vimentin-positive Müller cells were distributed throughout the inner retina of the Oz-eye. However, in the RAP-eye, (k) GFAP- and (o) vimentin-positive Müller cells were found surrounding the transplantation site. Similarly, in the OHT-eye, (l) GFAP- and (p) vimentin-positive Müller cells were found to surround the transplantation site. HE staining showed that in the (q) healthy eye and the (r) Oz-eye, the transplantation site had rosette-forming cell clusters with high nuclear-cytoplasmic ratios. In the (s) RAP-eye and the (t) OHT-eye, however, weakly basophilic cells were found to accumulate at the transplantation site. No obvious lymphocytes were detected around the transplantation site in four groups. GCL: ganglion cell layer; INL: inner nuclear layer; ONL: outer nuclear layer.