Fig. S1.

Expression of CD94, CD8a, and perforin in the CNS of MS patients. Frozen brain sections from MS patients were stained with mouse anti-human CD94 (1:50, HP-3D9; BD Pharmingen), mouse anti-human perforin (1:50, B-D48; Abcam) labeled with the Alexa Fluor 488 monoclonal antibody labeling kit (Invitrogen), and mouse anti-human CD8a (1:50, LT8; ABD Serotec) labeled with the Cy3 MAb labeling kit (GE Healthcare). Briefly, frozen brain sections were thawed at room temperature, fixed with acetone, and after a blocking step for 40 min with 2% (wt/vol) BSA, the antibodies were applied successively starting with anti-CD94 for 1 h at room temperature, which was detected using goat anti-mouse labeled with Alexa Fluor 647 (1:400; Life Technologies). Subsequently anti-perforin and anti-CD8a were applied for 1 h and 30 min, respectively. Staining was visualized using a Zeiss Axioscope microscope. A representative micrograph with triple fluorescence immunohistochemistry of four MS patients identifying brain-infiltrating CD8⁺ (red) and CD94⁺ (green) cells expressing perforin (white) is shown. Nuclei are stained with DAPI (blue). (Scale bar, 20 µm.)