The complement anaphylatoxin receptors are not required for the development of experimental autoimmune uveitis.

To determine if complement anaphylatoxin-mediated inflammation contributes to the development and progression of experimental autoimmune uveitis (EAU), we induced disease in wild type and complement anaphylatoxin receptor-deficient mice (C3a receptor(-/-), C5a receptor(-/-) and C3aR(-/-)/C5aR(-/-)) and evaluated the eyes three weeks post-induction. No differences in disease severity or in disease incidence were seen between wild type controls and anaphylatoxin receptor-deficient mice. Our data indicate that C3a and C5a-mediated functions are not critical to the development of EAU.

Histologic basis of variations in retinal pigment epithelium autofluorescence in eyes with geographic atrophy.

Purpose: Lipofuscin contained in the retinal pigment epithelium (RPE) is the main source of fundus autofluorescence (FAF), the target of an imaging method useful for estimating the progression of geographic atrophy (GA) in clinical trials. To establish a cellular basis for hyperfluorescent GA border zones, histologic autofluorescence (HAF) was measured at defined stages of RPE pathologic progression.

Design: Experimental study.

Retinal pigment epithelial expression of complement regulator CD46 is altered early in the course of geographic atrophy.

In geographic atrophy (GA), the non-neovascular end stage of age-related macular degeneration (AMD), the macular retinal pigment epithelium (RPE) progressively degenerates. Membrane cofactor protein (MCP, CD46) is the only membrane-bound regulator of complement expressed on the human RPE basolateral surface. Based on evidence of the role of complement in AMD, we hypothesized that altered CD46 expression on the RPE would be associated with GA development and/or progression.

Distribution of complement anaphylatoxin receptors and membrane-bound regulators in normal human retina.

To characterize the distribution of membrane-bound components of the complement system in normal human retina, eyes from eight human donors with no history of ocular disease, ranging in age from 47 to 85 years were examined using immunohistochemistry to localize the C3a receptor (C3aR), C5a receptor (C5aR), CD46, CD55, and CD59 in cryosections prepared from donor posterior segments. The C3aR was identified in the nerve fiber layer in a sawtooth-patterned band. Vimentin, used as a Müller cell marker, produced a similar staining pattern.

Genetic deficiency of C3 as well as CNS-targeted expression of the complement inhibitor sCrry ameliorates experimental autoimmune uveoretinitis.

In this report, we describe the effect of complement deficiency and inhibition on experimental autoimmune uveoretinitis (EAU). C57BL/6 mice genetically deficient in C3 (C3-/-) or expressing a soluble complement activation inhibitor (soluble complement receptor related protein Y or sCrry) in a CNS-targeted fashion, (sCrry/GFAP) were induced for EAU via peripheral immunisation with a peptide of amino acids 1-20 of human interphotoreceptor retinoid binding protein in complete Freund's adjuvant with concurrent intraperitoneal pertussis toxin. The incidence and severity of EAU in the mutant mice was compared with that in simultaneously induced C57BL/6 wild type mice.