Staphylococcal Panton‐Valentine leucotoxin targets retina through the ganglion cell layer in a rabbit toxin‐induced endophthalmitis model

• Published in: Acta ophthalmologica (Oxford, England) England), 2014-09, Vol.92 (s253), p.0-0
• Main Authors: HEITZ, P, TAWK, M, PRÉVOST, G, GAUCHER, D
• Format: Article
• Language: English
• Subjects: Ophthalmology
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/j.1755-3768.2014.T057.x

Purpose Staphylococcal leucotoxins form a cluster of bi‐component leucotoxins that are associated with tissue necrosis pathologies, such as necrotising pneumonia, osteomyelitis and endophtalmitis. Among them, Panton‐Valentine leucotoxine (PVL) is often associated with strains isolated in such diseases and seems to possess acute capabilities to promote necrosis. When injected into the rabbit vitreous, these toxins were proven to induce a huge inflammatory reaction that might concern the full eyeball. The purpose of this study was to identify the PVL target cells into the retina, using a rabbit model of endophtalmitis. Methods Three µg of LukS‐PV were injected in a series of rabbit eyes. After 1 hour, the eyes were enucleated. Frozen sections were prepared for immunofluorescence detection tests. PVL was immunolabelled using a specific antibody and a secondary fluorescent antibody. Co‐labelling with GFAP (Muller cells), RBPMS (ganglion cells), ChAT (starbust displaced amacrine cells) antibodies were realized. Left eyes were used as negative controls. Results LukS‐PV was present at the ganglion cells layer. A few dendrites in the inner plexiform layer were also noted. Co‐labeling experiments with the specific marker ChAT (acetylcholin transferase) segregated starbust displaced amacrine cells as a retinal target of LukS‐PV. 65% of the infected cells were ChAT positive. Conclusion At least, one retinal cell type, i.e. Starbust amacrine cells, can now be designated as a target of PVL and it will be important to explore how this cell fitness is sensitive to such a toxin compared with the activation of polymorphonuclear cells, and neurons that also were reported as possible targets.