A subpopulation of activated retinal macrophages selectively migrated to regions of cone photoreceptor stress, but had limited effect on cone death in a mouse model for type 2 Leber congenital amaurosis

Peter H. Tang, Mark J. Pierson, Neal D. Heuss, Dale S. Gregerson

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4 Citations (Scopus)

Abstract

Background Studies of antigen presentation in retina using mice that expressed green fluorescent protein (GFP) from a transgenic CD11c promoter found that retinal GFPhi cells possessed antigen presentation function. Subsequent studies found that these high GFPhi cells preferentially localized to sites of retinal injury, consistent with their APC function. Interest in the roles of macrophages in degenerative CNS diseases led us to study the GFPhi cells in a retinal model of neurodegeneration. We asked if apoptotic cone photoreceptor cell death in Rpe65−/− knockout mice induced the GFPhi cells, explored their relationship to resident microglia (MG), and tested their role in cone survival. Methods Rpe65−/− mice were bred to CD11cGFP mice on the B6/J background. CD11cGFPRpe65−/− mice were also backcrossed to CX3CR1YFP-creERROSADTA mice so that CX3CR1+ mononuclear cells could be depleted by Tamoxifen. Retinas were analyzed by immunohistochemistry, confocal microscopy, fluorescence fundoscopy and flow cytometry. Results Elevated numbers of GFPhi cells were concentrated in photoreceptor cell layers of CD11cGFPRpe65−/− mice coinciding with the peak of cone death at 2 to 4 weeks of age, and persisted for at least 14 months. After the initial wave of cone loss, a slow progressive loss of cones was found that continued to retain GFPhi cells in the outer retina. Sustained, four-week Tamoxifen depletions of the GFPhi cells and MG in Rpe65−/− mice from day 13 to day 41, and from day 390 to day 420 promoted a small increase in cone survival. We found no evidence that the GFPhi cells were recruited from the circulation; all data pointed to a MG origin. MG and GFPhi cells were well segregated in the dystrophic retina; GFPhi cells were foremost in the photoreceptor cell layer, while MG were concentrated in the inner retina. Conclusions The expression of GFP on a subset of retinal mononuclear cells in CD11cGFP mice identified a distinct population of cells performing functions previously attributed to MG. Although GFPhi cells dominated the macrophage response to cone death in the photoreceptor cell layer, their ablation led to only an incremental increase in cone survival. The ability to identify, ablate, and isolate these cells will facilitate analysis of this activated, antigen-presenting subset of MG.

Original languageEnglish (US)
Pages (from-to)70-81
Number of pages12
JournalMolecular and Cellular Neuroscience
Volume85
DOIs
StatePublished - Dec 2017

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Retinal Cone Photoreceptor Cells
Macrophages
Microglia
Retina
Photoreceptor Cells
Antigen Presentation
Tamoxifen
Green Fluorescent Proteins
Type 2 Amaurosis congenita of Leber
Central Nervous System Diseases
Knockout Mice
Confocal Microscopy

Keywords

  • Dendritic cell
  • Macrophage
  • Microglia
  • Neurodegeneration
  • Photoreceptors
  • RPE65
  • Retina

Cite this

@article{b4974f9494f045b984e17a7f7ae734d2,
title = "A subpopulation of activated retinal macrophages selectively migrated to regions of cone photoreceptor stress, but had limited effect on cone death in a mouse model for type 2 Leber congenital amaurosis",
abstract = "Background Studies of antigen presentation in retina using mice that expressed green fluorescent protein (GFP) from a transgenic CD11c promoter found that retinal GFPhi cells possessed antigen presentation function. Subsequent studies found that these high GFPhi cells preferentially localized to sites of retinal injury, consistent with their APC function. Interest in the roles of macrophages in degenerative CNS diseases led us to study the GFPhi cells in a retinal model of neurodegeneration. We asked if apoptotic cone photoreceptor cell death in Rpe65−/− knockout mice induced the GFPhi cells, explored their relationship to resident microglia (MG), and tested their role in cone survival. Methods Rpe65−/− mice were bred to CD11cGFP mice on the B6/J background. CD11cGFPRpe65−/− mice were also backcrossed to CX3CR1YFP-creERROSADTA mice so that CX3CR1+ mononuclear cells could be depleted by Tamoxifen. Retinas were analyzed by immunohistochemistry, confocal microscopy, fluorescence fundoscopy and flow cytometry. Results Elevated numbers of GFPhi cells were concentrated in photoreceptor cell layers of CD11cGFPRpe65−/− mice coinciding with the peak of cone death at 2 to 4 weeks of age, and persisted for at least 14 months. After the initial wave of cone loss, a slow progressive loss of cones was found that continued to retain GFPhi cells in the outer retina. Sustained, four-week Tamoxifen depletions of the GFPhi cells and MG in Rpe65−/− mice from day 13 to day 41, and from day 390 to day 420 promoted a small increase in cone survival. We found no evidence that the GFPhi cells were recruited from the circulation; all data pointed to a MG origin. MG and GFPhi cells were well segregated in the dystrophic retina; GFPhi cells were foremost in the photoreceptor cell layer, while MG were concentrated in the inner retina. Conclusions The expression of GFP on a subset of retinal mononuclear cells in CD11cGFP mice identified a distinct population of cells performing functions previously attributed to MG. Although GFPhi cells dominated the macrophage response to cone death in the photoreceptor cell layer, their ablation led to only an incremental increase in cone survival. The ability to identify, ablate, and isolate these cells will facilitate analysis of this activated, antigen-presenting subset of MG.",
keywords = "Dendritic cell, Macrophage, Microglia, Neurodegeneration, Photoreceptors, RPE65, Retina",
author = "Tang, {Peter H.} and Pierson, {Mark J.} and Heuss, {Neal D.} and Gregerson, {Dale S.}",
year = "2017",
month = "12",
doi = "10.1016/j.mcn.2017.09.002",
language = "English (US)",
volume = "85",
pages = "70--81",
journal = "Molecular and Cellular Neuroscience",
issn = "1044-7431",
publisher = "Academic Press Inc.",

}

TY - JOUR

T1 - A subpopulation of activated retinal macrophages selectively migrated to regions of cone photoreceptor stress, but had limited effect on cone death in a mouse model for type 2 Leber congenital amaurosis

AU - Tang, Peter H.

AU - Pierson, Mark J.

AU - Heuss, Neal D.

AU - Gregerson, Dale S.

PY - 2017/12

Y1 - 2017/12

N2 - Background Studies of antigen presentation in retina using mice that expressed green fluorescent protein (GFP) from a transgenic CD11c promoter found that retinal GFPhi cells possessed antigen presentation function. Subsequent studies found that these high GFPhi cells preferentially localized to sites of retinal injury, consistent with their APC function. Interest in the roles of macrophages in degenerative CNS diseases led us to study the GFPhi cells in a retinal model of neurodegeneration. We asked if apoptotic cone photoreceptor cell death in Rpe65−/− knockout mice induced the GFPhi cells, explored their relationship to resident microglia (MG), and tested their role in cone survival. Methods Rpe65−/− mice were bred to CD11cGFP mice on the B6/J background. CD11cGFPRpe65−/− mice were also backcrossed to CX3CR1YFP-creERROSADTA mice so that CX3CR1+ mononuclear cells could be depleted by Tamoxifen. Retinas were analyzed by immunohistochemistry, confocal microscopy, fluorescence fundoscopy and flow cytometry. Results Elevated numbers of GFPhi cells were concentrated in photoreceptor cell layers of CD11cGFPRpe65−/− mice coinciding with the peak of cone death at 2 to 4 weeks of age, and persisted for at least 14 months. After the initial wave of cone loss, a slow progressive loss of cones was found that continued to retain GFPhi cells in the outer retina. Sustained, four-week Tamoxifen depletions of the GFPhi cells and MG in Rpe65−/− mice from day 13 to day 41, and from day 390 to day 420 promoted a small increase in cone survival. We found no evidence that the GFPhi cells were recruited from the circulation; all data pointed to a MG origin. MG and GFPhi cells were well segregated in the dystrophic retina; GFPhi cells were foremost in the photoreceptor cell layer, while MG were concentrated in the inner retina. Conclusions The expression of GFP on a subset of retinal mononuclear cells in CD11cGFP mice identified a distinct population of cells performing functions previously attributed to MG. Although GFPhi cells dominated the macrophage response to cone death in the photoreceptor cell layer, their ablation led to only an incremental increase in cone survival. The ability to identify, ablate, and isolate these cells will facilitate analysis of this activated, antigen-presenting subset of MG.

AB - Background Studies of antigen presentation in retina using mice that expressed green fluorescent protein (GFP) from a transgenic CD11c promoter found that retinal GFPhi cells possessed antigen presentation function. Subsequent studies found that these high GFPhi cells preferentially localized to sites of retinal injury, consistent with their APC function. Interest in the roles of macrophages in degenerative CNS diseases led us to study the GFPhi cells in a retinal model of neurodegeneration. We asked if apoptotic cone photoreceptor cell death in Rpe65−/− knockout mice induced the GFPhi cells, explored their relationship to resident microglia (MG), and tested their role in cone survival. Methods Rpe65−/− mice were bred to CD11cGFP mice on the B6/J background. CD11cGFPRpe65−/− mice were also backcrossed to CX3CR1YFP-creERROSADTA mice so that CX3CR1+ mononuclear cells could be depleted by Tamoxifen. Retinas were analyzed by immunohistochemistry, confocal microscopy, fluorescence fundoscopy and flow cytometry. Results Elevated numbers of GFPhi cells were concentrated in photoreceptor cell layers of CD11cGFPRpe65−/− mice coinciding with the peak of cone death at 2 to 4 weeks of age, and persisted for at least 14 months. After the initial wave of cone loss, a slow progressive loss of cones was found that continued to retain GFPhi cells in the outer retina. Sustained, four-week Tamoxifen depletions of the GFPhi cells and MG in Rpe65−/− mice from day 13 to day 41, and from day 390 to day 420 promoted a small increase in cone survival. We found no evidence that the GFPhi cells were recruited from the circulation; all data pointed to a MG origin. MG and GFPhi cells were well segregated in the dystrophic retina; GFPhi cells were foremost in the photoreceptor cell layer, while MG were concentrated in the inner retina. Conclusions The expression of GFP on a subset of retinal mononuclear cells in CD11cGFP mice identified a distinct population of cells performing functions previously attributed to MG. Although GFPhi cells dominated the macrophage response to cone death in the photoreceptor cell layer, their ablation led to only an incremental increase in cone survival. The ability to identify, ablate, and isolate these cells will facilitate analysis of this activated, antigen-presenting subset of MG.

KW - Dendritic cell

KW - Macrophage

KW - Microglia

KW - Neurodegeneration

KW - Photoreceptors

KW - RPE65

KW - Retina

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U2 - 10.1016/j.mcn.2017.09.002

DO - 10.1016/j.mcn.2017.09.002

M3 - Article

C2 - 28889993

AN - SCOPUS:85029815198

VL - 85

SP - 70

EP - 81

JO - Molecular and Cellular Neuroscience

JF - Molecular and Cellular Neuroscience

SN - 1044-7431

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