All tissues used for immunohistochemistry for histopathology were immersion fixed in 4 % paraformaldehyde. Tissue used for sections was embedded in OCT media. 7 μm sections were obtained and either stained with hematoxylin and eosin or processed for immunohistochemistry. Primary antibodies used include rabbit anti-Iba1 (Wako Chem, Osaka, Japan), CD3 (Rabbit anti-mouse CD3, Abcam, Cambridge, MA) and CD19 (rat anti-mouse CD19, Abcam). Secondary antibodies used were either goat anti-rabbit Cy3 or goat anti-rat Alexa 488 diluted 1:300 (both life technologies). It was also necessary to enhance the endogenous signal of DsRed+ lymphocytes through immunohistochemical approaches. Sections were incubated with the primary antibody mouse-anti DsRed (St. Cruz Biotechnologies, Dallas, TX) or rabbit-anti red fluorescent protein (Abcam) and counterstained with DAPI (Sigma, St. Louis, MO) to facilitate orientation.
Retinal whole mounts were preserved in 4 % paraformaldehyde. Retinas where preincubated in 0.3 % Triton X-100/PBS (Sigma) for 4 h and blocked in 0.1 % BSA/0.3 % Triton X-100/PBS for 1 h. Primary antibodies were diluted 1:300 in 0.3 % Triton X-100/PBS and incubated for 18 h at 4 °C. After extensive washing in PBS retinas were incubated with the secondary antibodies (1:200 in PBS) for three hours. Retinal wholemounts were coverslipped and images were taken on an Olympus BX41 microscope.
Retinal whole mounts were preserved in 4 % paraformaldehyde. Retinas where preincubated in 0.3 % Triton X-100/PBS (Sigma) for 4 h and blocked in 0.1 % BSA/0.3 % Triton X-100/PBS for 1 h. Primary antibodies were diluted 1:300 in 0.3 % Triton X-100/PBS and incubated for 18 h at 4 °C. After extensive washing in PBS retinas were incubated with the secondary antibodies (1:200 in PBS) for three hours. Retinal wholemounts were coverslipped and images were taken on an Olympus BX41 microscope.