Fig. 4

Complement Deposition on POS in Mouse Models of GA and in GA Patient Tissue: Panel A: Image of mouse retinal Sect. 5 h after RPE damage caused by intravenous injection of NaIO_3. Immunofluorescence shows C1q deposition on POS, which occurs in conjunction with C3 prior to decrease in retinal function by day 7; Panels B and C: Images of retinal sections from patients with GA. Immunofluorescence shows C4 and C3 deposition on photoreceptor cell outer segments (POS) in a healthy region of retina just outside the edge of an expanding lesion, consistent with complement activation preceding loss of photoreceptor neurons. C4 deposition directly implicates the classical and/or lectin pathways since it occurs upstream of C3 and the alternative or amplification pathways [6]