Abstract
Purpose::
Previously, natural killer (NK) cells and microglia have been described in the retina. The purpose of our work is to determine whether other immune cell populations are endogenous to the retinal immune system.
Methods::
Whole mount retina were prepared and immunohistochemistry was performed with antibodies to T-bet and GATA-3. The whole mount retina IHC staining was analyzed with confocal microscopy. Retina single cell suspensions were prepared via trypsin digestion and analyzed via flow cytometry. Antibodies used in flow cytometry included CD4, CD8, NK1.1, TCR, Thy1, and CD3. A CXCR6 green fluorescent protein (gfp) knock-in mouse was also used to localize immune cells homing to the retina.
Results::
Whole mount retina IHC revealed two layers within the retina containing T-bet positive cells. Flow cytometry showed a group of CD3lo, NK1.1+, TCRlo/-, Thy1+ cells. The CXCR6 gfp/+ mouse showed cells gfp+ in 85 day old mice localized to 3 layers of the retina while 30 day old mice showed no gfp+ cells.
Conclusions::
These preliminary results may represent a group of cells in the retina that have not been described previously, namely T-bet+, CD3lo, NK1.1+, TCRlo/-, Thy1+. We also found CXCR6 positive cells in the same distribution as the T-bet staining. It appears that the retina begins to have CXCR6 positive cells between 30 and 85 days after birth.
Keywords: immune tolerance/privilege • retina • microscopy: confocal/tunneling