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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Cell Line, Culture Media, Cytokines, Endotoxins, Female, Immune Tolerance, Interleukin-10, Macrophages, Mice, Mice, Inbred C57BL, Nitric Oxide, Retina, Retinal Pigment Epithelium, Tissue Culture Techniques, alpha-MSH.
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Does the immune privileged retina mediate an alternative activation of J774A.1 cells? Context: 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. 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. 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).
assistant
Healthy RPE not only suppresses inflammatory activity, it promotes an alternative activation of macrophages that can further promote immune privilege. Final Decision: yes