Abstract
Purpose :
To examine how inflammatory cytokines influence the interaction between retinal pigment epithelial (RPE) cells and the complement system in relation to age-related macular degeneration (AMD).
Methods :
Post-confluent ARPE-19 were cultivated in serum-free conditions, exposed to inflammatory stimulation by CD3/CD28 stimulated PBMC or interferon gamma (IFNγ) and tumor necrosis factor alpha (TNFα) for 48 hours. After multiple washes, the primed ARPE-19 were exposed to diluted serum from healthy donors or complement factor B (CFB)-deficient serum. Anti-C5 was added in some experiments. Deposition of membrane attack complexes (MAC) was examined by modified use of a MAC-ELISA kit and by immunofluorescence.
Results :
MAC was deposited on ARPE-19 exposed to either stimulated PBMC or IFNγ and TNFα. MAC was not deposited on unstimulated ARPE-19. Lack of complement factor B or inhibition of C5 also abrogated the MAC-deposition, while reconstitution of deficient serum with CFB resulted in MAC-deposition.
Conclusions :
Inflammatory stimulation of ARPE-19 promoted alternative pathway activation of complement and deposition of MAC. These results suggests that circulating inflammatory mediators may increase susceptibility to local complement activation and MAC-deposition on RPE.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.