Purchase this article with an account.
D. B. Spencer, E. J. Lee, S. R. Planck, J. T. Rosenbaum; Characterization of the Response of CD11c+ Dendritic Cells in the Murine Iris to Antigen Challenge. Invest. Ophthalmol. Vis. Sci. 2010;51(13):4840.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Dendritic cells (DC) and macrophages are phagocytic, antigen-presenting cells (APCs) that play a crucial role in initiating the immune response throughout the body. However, the role of these cells as APCs in the immunoprivileged eye remains unclear. Through the use of non-invasive, intravital microscopy, we examined the behavior of iris-resident CD11c+ DCs and CD11c- phagocytic cells in response to inflammatory stimulus.
Mice expressing Yellow Fluorescent Protein under the control of the CD11c promoter were challenged via intravitreal injection with LPS (200 ng) and labeled ovalbumin (50 µg). Challenged irises were imaged at 1-7dpi via in vivo videomicroscopy and in vitro confocal microscopy, and the behavior of CD11c+ cells and labeled phagocytic cells were analyzed.
Iris-resident CD11c+ DCs demonstrated a characteristic dendriform appearance prior to intravitreal injection, after which they assumed a round appearance. The vast majority (>99%) of CD11c+ cells did not uptake labeled antigen. In contrast, iris-resident CD11c- phagocytic cells were highly visible after antigen challenge due to the uptake of labeled antigen. Circulating CD11c+ cells accumulated in the iris vessels of the antigen-challenged eye within several hours of intravitreal injection, exhibiting rolling and sticking behavior that peaked at 12-24 hours post injection. However, we did not observe diapedesis of adhered CD11c+ cells into the iris stroma. Additionally, neither round, iris-resident CD11c+ DCs nor antigen-labeled iris-resident CD11c- cells were observed to exit the iris via the vasculature (observation period: 6hrs).
Intravital examination of iris-resident CD11c+ and CD11c- phagocytic cells in our model demonstrates the presence of two distinct populations. In contrast with reports of CD11c+ DCs elsewhere in the body, those in the iris did not exhibit uptake of labeled antigen, whereas phagocytosis was observed by CD11c- cells. Neither cell type was observed to exit the eye via the vasculature. These behaviors may contribute to the sequestration of ocular antigens from the immune system.
This PDF is available to Subscribers Only