Retinal microglia are activated by systemic fungal infection.

PURPOSE We determined whether systemic fungal infection could cause activation of retinal microglia and, therefore, could be potentially harmful for patients with retinal degenerative diseases. METHODS Activation of retinal microglia was measured in a model of sublethal invasive candidiasis in C57BL/6J mice by confocal immunofluorescence and flow cytometry analysis, using anti-CD11b, anti-Iba1, anti-MHCII, and anti-CD45 antibodies. RESULTS Systemic fungal infection causes activation of retinal microglia, with phenotypic changes in morphology, surface markers expression, and microglial relocation in retinal layers. CONCLUSIONS As an excessive or prolonged microglial activation may lead to chronic inflammation with severe pathological side effects, causing or worsening the course of retinal dystrophies, a systemic infection may represent a risk factor to be considered in patients with ocular neurodegenerative diseases, such as diabetic retinopathy, glaucoma, age-related macular degeneration, or retinitis pigmentosa.