Chun H Lau1, Andrew W Taylor. 1. Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA 02116, USA.
Abstract
PURPOSE: We have previously found that retinal pigment epithelial (RPE) cells suppressed endotoxin-stimulated macrophages; moreover, it induced expression of anti-inflammatory cytokines. We further assessed the possibility that the RPE is alternatively activating macrophages. METHODS: J774A.1 cells were stimulated with endotoxin and treated with the conditioned media (CM) of RPE, or neuroretinal eyecups from healthy mouse eyes. The supernatant was assayed for IL-1 beta, TNF-alpha, IL-6, IL-12(p70), and IL-10, and for nitric-oxide generation. The RPE conditioned media (RPE CM) was absorbed of known soluble factors to identify the factor that augments nitric-oxide generation. RESULTS: We found the RPE CM suppressed all cytokine production except IL-10, and augmented nitric-oxide generation. The augmented nitric-oxide levels were mediated by RPE derived alpha-melanocyte stimulating hormone (alpha-MSH). CONCLUSIONS: Healthy RPE not only suppresses inflammatory activity, it promotes an alternative activation of macrophages that can further promote immune privilege.
PURPOSE: We have previously found that retinal pigment epithelial (RPE) cells suppressed endotoxin-stimulated macrophages; moreover, it induced expression of anti-inflammatory cytokines. We further assessed the possibility that the RPE is alternatively activating macrophages. METHODS:J774A.1 cells were stimulated with endotoxin and treated with the conditioned media (CM) of RPE, or neuroretinal eyecups from healthy mouse eyes. The supernatant was assayed for IL-1 beta, TNF-alpha, IL-6, IL-12(p70), and IL-10, and for nitric-oxide generation. The RPE conditioned media (RPE CM) was absorbed of known soluble factors to identify the factor that augments nitric-oxide generation. RESULTS: We found the RPE CM suppressed all cytokine production except IL-10, and augmented nitric-oxide generation. The augmented nitric-oxide levels were mediated by RPE derived alpha-melanocyte stimulating hormone (alpha-MSH). CONCLUSIONS: Healthy RPE not only suppresses inflammatory activity, it promotes an alternative activation of macrophages that can further promote immune privilege.
Authors: Matthew J Delano; Philip O Scumpia; Jason S Weinstein; Dominique Coco; Srinivas Nagaraj; Kindra M Kelly-Scumpia; Kerri A O'Malley; James L Wynn; Svetlana Antonenko; Samer Z Al-Quran; Ryan Swan; Chun-Shiang Chung; Mark A Atkinson; Reuben Ramphal; Dmitry I Gabrilovich; Wesley H Reeves; Alfred Ayala; Joseph Phillips; Drake Laface; Paul G Heyworth; Michael Clare-Salzler; Lyle L Moldawer Journal: J Exp Med Date: 2007-06-04 Impact factor: 14.307