Retinal microglia are activated by systemic fungal infection

Purpose: To determine 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 (i) confocal immunofluorescence and (ii) 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 re-location 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.

This work was supported by projects grants from the Spanish Ministry of Economy and Competitiveness-FEDER BFU2012-36845, Instituto de Salud Carlos III RETICS RD12/0034/0010 and ONCE to Nicolás Cuenca and Instituto de Salud Carlos III PI080556 to Daniel Gozalbo. Violeta Gómez-Vicente is a MICINN-Juan de la Cierva post-doctoral fellow (JCI-2009-05224).