PURPOSE: To characterize the interactions between resident macrophage populations and nerves in naïve and injured corneas of the mouse eye. METHODS: Corneas from wild-type (WT) C57BL/6J, BALB/cJ, and transgenic Cx3cr1-eGFP mice were subjected to a 1-mm central epithelial debridement injury. The eyes were fixed and immunostained as flat mounts with a range of antibodies to identify macrophages, neurons, and Schwann cells. Interactions between nerves and immune cells were analyzed and quantitated using three-dimensional reconstructions of confocal microscopy images. Naïve eyes acted as controls. RESULTS: A distinctive association between resident immune cells and corneal nerves was noted in the peripheral or perilimbal stromal nerve trunks. These epineurial cells were mostly Cx3cr1(+) Iba-1(+) major histocompatibility complex (MHC) class II(+) F4/80(+) CD11b(+) macrophages. The number of nerve-associated macrophages was greater in WT BALB/c mice than in C57BL/6J mice. There were no qualitative or quantitative differences in the circumferential distribution of nerve-associated macrophages in the cornea. Sterile corneal epithelial debridement led to a dissociation of macrophages from peripheral nerve trunks as early as 2 hours postinjury, with numbers returning to baseline after 72 hours. This dissociation was Cx3cr1 dependent. CONCLUSIONS: This study is the first to highlight a direct physical association between nerves and resident immune cells in the murine cornea. Furthermore, we reveal that this association in normal eyes is responsive to central corneal epithelial injury and is partly mediated by Cx3cr1 signaling. This association may serve as an indicator of malfunctioning neuroimmune communication in disease states such as neurotrophic keratitis and peripheral neuropathy.
PURPOSE: To characterize the interactions between resident macrophage populations and nerves in naïve and injured corneas of the mouse eye. METHODS: Corneas from wild-type (WT) C57BL/6J, BALB/cJ, and transgenic Cx3cr1-eGFP mice were subjected to a 1-mm central epithelial debridement injury. The eyes were fixed and immunostained as flat mounts with a range of antibodies to identify macrophages, neurons, and Schwann cells. Interactions between nerves and immune cells were analyzed and quantitated using three-dimensional reconstructions of confocal microscopy images. Naïve eyes acted as controls. RESULTS: A distinctive association between resident immune cells and corneal nerves was noted in the peripheral or perilimbal stromal nerve trunks. These epineurial cells were mostly Cx3cr1(+) Iba-1(+) major histocompatibility complex (MHC) class II(+) F4/80(+) CD11b(+) macrophages. The number of nerve-associated macrophages was greater in WT BALB/c mice than in C57BL/6J mice. There were no qualitative or quantitative differences in the circumferential distribution of nerve-associated macrophages in the cornea. Sterile corneal epithelial debridement led to a dissociation of macrophages from peripheral nerve trunks as early as 2 hours postinjury, with numbers returning to baseline after 72 hours. This dissociation was Cx3cr1 dependent. CONCLUSIONS: This study is the first to highlight a direct physical association between nerves and resident immune cells in the murine cornea. Furthermore, we reveal that this association in normal eyes is responsive to central corneal epithelial injury and is partly mediated by Cx3cr1 signaling. This association may serve as an indicator of malfunctioning neuroimmune communication in disease states such as neurotrophic keratitis and peripheral neuropathy.
Authors: Carlos Belmonte; Jason J Nichols; Stephanie M Cox; James A Brock; Carolyn G Begley; David A Bereiter; Darlene A Dartt; Anat Galor; Pedram Hamrah; Jason J Ivanusic; Deborah S Jacobs; Nancy A McNamara; Mark I Rosenblatt; Fiona Stapleton; James S Wolffsohn Journal: Ocul Surf Date: 2017-07-20 Impact factor: 5.033
Authors: Ann R Strom; Dennis E Cortés; Sara M Thomasy; Philip H Kass; Mark J Mannis; Christopher J Murphy Journal: Vet Ophthalmol Date: 2015-03-06 Impact factor: 1.644
Authors: Tina B McKay; Yashar Seyed-Razavi; Chiara E Ghezzi; Gabriela Dieckmann; Thomas J F Nieland; Dana M Cairns; Rachel E Pollard; Pedram Hamrah; David L Kaplan Journal: Prog Retin Eye Res Date: 2018-11-16 Impact factor: 21.198