PURPOSE: The purposes of this study were to identify iNOS-producing retinal cells and to determine whether lack of iNOS facilitates MCMV spread and replication in the retina. METHODS: Immunosuppressed (IS) iNOS(-/-) mice or C57BL/6 (wild-type) mice were inoculated with 5 x 10(4) PFU of MCMV K181 strain (K181) via the supraciliary route. Injected eyes were collected at several times after inoculation and examined by plaque assay for replicating virus, RT-PCR for iNOS RNA, Western blot for iNOS protein and by staining for MCMV early antigen (EA), iNOS, and retinal cell antigens. RESULTS: iNOS mRNA and iNOS proteins were expressed in the MCMV-injected eye of wild-type mice. Most iNOS-producing cells were F4/80-positive, including macrophages, RPE-derived macrophages, and resident microglia. Significantly higher titers of virus were recovered from the injected eyes, and more infected cells were detected in the retina of IS iNOS(-/-) mice than in IS wild-type mice. Retinal necrosis and loss of retinal architecture throughout the retina were noted in IS iNOS(-/-) mice, whereas cytomegalic cells and retinitis were present only in the peripheral retina of IS wild-type mice. CONCLUSIONS: iNOS produced by macrophages, especially resident macrophages including microglia and RPE derived macrophages, plays an important role in limiting spread of MCMV in the retina.
PURPOSE: The purposes of this study were to identify iNOS-producing retinal cells and to determine whether lack of iNOS facilitates MCMV spread and replication in the retina. METHODS: Immunosuppressed (IS) iNOS(-/-) mice or C57BL/6 (wild-type) mice were inoculated with 5 x 10(4) PFU of MCMV K181 strain (K181) via the supraciliary route. Injected eyes were collected at several times after inoculation and examined by plaque assay for replicating virus, RT-PCR for iNOS RNA, Western blot for iNOS protein and by staining for MCMV early antigen (EA), iNOS, and retinal cell antigens. RESULTS:iNOS mRNA and iNOS proteins were expressed in the MCMV-injected eye of wild-type mice. Most iNOS-producing cells were F4/80-positive, including macrophages, RPE-derived macrophages, and resident microglia. Significantly higher titers of virus were recovered from the injected eyes, and more infected cells were detected in the retina of IS iNOS(-/-) mice than in IS wild-type mice. Retinal necrosis and loss of retinal architecture throughout the retina were noted in IS iNOS(-/-) mice, whereas cytomegalic cells and retinitis were present only in the peripheral retina of IS wild-type mice. CONCLUSIONS:iNOS produced by macrophages, especially resident macrophages including microglia and RPE derived macrophages, plays an important role in limiting spread of MCMV in the retina.
Authors: Juan Mo; Brendan Marshall; Jason Covar; Nancy Y Zhang; Sylvia B Smith; Sally S Atherton; Ming Zhang Journal: Invest Ophthalmol Vis Sci Date: 2014-10-08 Impact factor: 4.799