Department of Ophthalmology, University of Minnesota School of Medicine, 2001 6th Street SE, Minneapolis, MN 55455, USA.
Neurobiol Dis. 2010 Oct;40(1):177-84. doi: 10.1016/j.nbd.2010.05.022. Epub 2010 May 23.
The presence and activity of dendritic cells (DC) in retina is controversial, as these cells are difficult to identify in retina due to limited markers and sparse numbers. Transgenic mice that express green fluorescent protein (GFP) on the CD11c promoter to label DC allowed the visualization and quantification of retinal DC. Two retina injury models, the optic nerve crush (ONC) and light injury, were used to study their injury response. Many GFP(+) DC were tightly associated with retinal ganglion cell nerve fibers following ONC, while very few microglia (GFP(-)CD11b(+) cells) were found in close contact. The GFP(+) cells were greatly elevated in the outer plexiform layer following photic injury. All of the GFP(+) DC were CD11b(+), suggesting a myeloid origin. In addition, the GFP(+) DC upregulated expression of MHC class II after injury, while the GFP(-)CD11b(+) microglia did not. This study shows that DC were found in the retina and that they rapidly responded to neural injuries. We propose that they are a previously overlooked population, distinct from microglia, and may be important in the injury response.
树突状细胞（DC）在视网膜中的存在和活性存在争议，因为由于标记物有限和数量稀少，这些细胞在视网膜中难以识别。表达在 CD11c 启动子上的绿色荧光蛋白（GFP）的转基因小鼠用于标记 DC，从而可以可视化和定量视网膜 DC。使用视神经挤压（ONC）和光损伤两种视网膜损伤模型来研究它们的损伤反应。在 ONC 后，许多 GFP(+) DC 与视网膜神经节细胞神经纤维紧密相关，而很少发现与 GFP(-)CD11b(+)细胞紧密接触的小胶质细胞。在光损伤后，外丛状层中的 GFP(+)细胞大量升高。所有的 GFP(+) DC 均为 CD11b(+)，提示其来源于髓系。此外，GFP(+) DC 在损伤后上调 MHC Ⅱ类的表达，而 GFP(-)CD11b(+)小胶质细胞则没有。这项研究表明，在视网膜中发现了 DC，并且它们对神经损伤迅速做出反应。我们提出，它们是一个以前被忽视的群体，与小胶质细胞不同，可能在损伤反应中很重要。
