Immunolocalization of IL-1ß and IL-6 in optic nerves of patients with AIDS

Abstract

PURPOSE. Immunohistochemical procedures were employed to test the hypothesis that cytokines such as interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) are involved in AIDS-related optic neuropathy and to determine the primary cell types involved. METHODS. Fixed sections of six human HIV-1 infected optic nerves were immunostained for the presence of IL-1ß and IL-6, using horseradish peroxidase and diaminobenzidine as markers. RESULTS. IL-1ß and IL-6 were found in astrocytes, macrophages, microglia, and endothelial cells. The great majority of astrocytes demonstrated strong immunoreactivity. CONCLUSION. Our findings support the premise that IL-1ß and IL-6 are significant pro-inflammatory mediators in AIDS-related optic neuropathy. This finding supports the theory that HIV infection stimulates the release of IL-1ß and IL-6 in astrocytes, macrophages, and endothelial cells in the optic nerve which ultimately leads to demyelination, astrogliosis, and neuronal destruction.