Multimodal evaluation of an interphotoreceptor retinoid-binding protein-induced mouse model of experimental autoimmune uveitis

Abstract

We aimed to characterize the vascular phenotypes of an experimental autoimmune retinal uveitis (EAU) model induced by interphotoreceptor retinoid-binding protein (IRBP) using multimodal imaging techniques. We systemically administered IRBP or vehicle to adult C57BL/6 mice. Fundus photography, optical coherence tomography (OCT), in vivo live confocal imaging using different tracers, OCT angiography (OCTA), and electroretinography (ERG) were performed after IRBP immunization. Hematoxylin and eosin and immunofluorescence staining were performed to characterize the immune response and vascular permeability. Mice with EAU exhibited perivascular inflammation, vitritis, and superficial retinal inflammation on fundus photography and OCT. H&E revealed immune cell infiltration in the perivascular area of the retina and choroid accompanied by a significant degree of perivasculitis that subsequently damaged photoreceptors 3 weeks postimmunization. Immunofluorescence staining showed subsequent transcytosis induction after local microglial activation followed by neutrophil recruitment in the perivascular area. Transcytosis in the superficial and deep vascular areas was improved by immune cell suppression. Intravital in vivo confocal imaging showed signs of neutrophil infiltration and obstructive vasculitis with perivascular leakage 3 weeks postimmunization. OCTA revealed a significant decrease in vascular flow in the deep capillary layer of the retina. Functional analysis showed that scotopic responses were intact at 2 weeks; however, normal photopic and scotopic responses were hardly detected in mice with EAU mice at 3 weeks postimmunization. Our data suggest that inflammatory cell activation and subsequent transcytosis induction in endothelial cells might be a major pathogenic factor for vascular leakage in uveitis, providing new insights into the pathophysiology of retinal vasculitis in noninfectious uveitis.

Low-dose melittin is safe for intravitreal administration and ameliorates inflammation in an experimental model of uveitis

“…This interaction has been reported as rapid and dependent on several elements, such as peptide/lipid ratio and peptide concentration, although not described as time-dependent ( Jamasbi et al., 2016 ; Hong et al., 2019 ; Pereira et al., 2020 ). Altogether, these factors might have contributed to the difference observed in long exposure times, an outcome also reported in other cell viability studies with MEL ( Park et al., 2011 ; Tipgomut et al., 2018 ; Yang et al., 2022 ).…”

Deciphering perivascular macrophages and microglia in the retinal ganglion cell layers

“…In addition, other disease models such as Inter-photoreceptor Retinoid Binding Protein (IRBP) induced autoimmune uveitis have similar phenotypes with the NaIO3 model (Fig. S3), as shown in a previous article 13 . In some inflammatory conditions, the microglia in the each layer seem to be adhere near the capillary plexus and the microglia of the each layer can easily be revealed.…”

“…Analysis was done according to each experiment. To induce IRBP induced autoimmune uveitis, IRBP 1-20 (GenScript, Piscataway, New Jersey, USA) was emulsified in complete Freund's adjuvant (CFA, 1:1 vol/vol; Sigma-Aldrich) and systemically administered intramuscularly (0.2 mL emulsification per mouse, at the tail base) as previously described 13 .…”

Establishment of the reproducible branch retinal artery occlusion mouse model and intravital longitudinal imaging of the retinal CX3CR1-GFP+ cells after spontaneous arterial recanalization

“…Real-time intravital images and movies of the BRAO model were acquired by using a previously established confocal microscopy setup (30,34,38), as shown in Figure 1A. First, a target vessel labeled by lectin 649 staining was selected in the maximum angle of view (AOV), which was previously measured to be about 48 • .…”

“…Interestingly, inflammatory cell was most activated at day 3 at the starting time point of recanalization. The morphological changes from ramified to amoeboid form (38,43,44) are considered as typical activation markers of the retinal microglia. Figures 4A-C shows that morphologic changes and CD86, one of the microglial activation makers (45), expression changes of the CX3CR1-GFP + cells are also most activated at day 3.…”