Purchase this article with an account.
Binit Kumar, Siobhan Cashman, Rajendra Kumar-Singh; Complement Membrane Attack Complex activates the NLRP3 inflammasome in experimental autoimmune uveitis and inhibition by AAV mediated delivery of sCD59. Invest. Ophthalmol. Vis. Sci. 2018;59(9):5666.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The Complement Membrane attack complex (MAC) is a major contributor of cellular inflammation and cell death in various ocular diseases. Here, we investigate the role of the MAC in activation of the NLRP3 inflammasome in experimental autoimmune uveitis (EAU). Furthermore, we investigate the potential application of adeno-associated virus (AAV) mediated delivery of sCD59 (protectin) for attenuation of the inflammasome and ensuing pathology in EAU.
We induced EAU in C57Bl/6J and C9-/- mice over a period of 24 days. MAC deposition in EAU retina was quantified using immunohistochemistry. NLRP3, Caspase 1 and ASC protein expression was measured by western analyses and cytokine release including IL-1β, IFN-γ and IL-17 were analyzed by ELISA and qPCR of retinal extracts. Retinal function and clinical changes were quantified by ERG and histology respectively. These same parameters were subsequently measured in a group of mice that had been pre-injected with either a control GFP-expressing AAV vector (AAVCAGGFP) or sCD59 (AAVCAGsCD59)- a vector currently in Phase I for the treatment of dry age-related macular degeneration.
Relative to the normal retina, EAU retina exhibited 70% increased MAC deposition and a two-fold increased activation of the NLRP3 inflammasome as well as increased secretion of IL-1β, IFN-γ and IL-17. C9-/- mice that are unable to form MAC did not display a significant activation of the NLRP3 inflammasome, or elevated secretion of IL-1β or IFN-γ. However, EAU-associated pathophysiology including retinal structure and function were not rescued in C9-/- mice. Surprisingly, a single intravitreal injection of AAVCAGsCD59 in EAU mice inhibited deposition of MAC by 45% and activation of the NLRP3 inflammasome by 60% and secretion of IL-1β, IFN-γ, and IL-17 relative to controls. We found significantly lower clinical and histological scores in AAVCAGsCD59 retinas relative to controls. ERG photopic and scotopic data indicated more than 40% improved retinal function in AAVCAGsCD59 retinas relative to AAVCAGGFP retinas.
MAC is directly involved in activation of the NLRP3 inflammasome in EAU and therapeutic modalities regulating MAC deposition such as AAV mediated delivery of sCD59 may potentially be useful in treating uveitis.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
This PDF is available to Subscribers Only