Figure 1. Autoreactive myelin-specific CD8 T-cells suppress CD4 T-cell mediated autoimmune demyelinating disease.

(A) MOG- (or OVA)-specific CD8 T-cells (purity ≧95%) were transferred one day prior to primary EAE induction. EAE clinical severity was evaluated in a blinded manner and the two groups were compared. Mean clinical scores ± SEM are shown on the y-axis versus days post-immunization on the x-axis. Data are representative of at least three independent experiments (n=15 per condition).

(B) MOG- (or OVA)-specific CD8 T-cells were transferred into naive CD45.1+ mice on day −2. On day −1, all mice received CFSE-labeled MOG_35–55-specific transgenic (2D2) CD45.2+ CD4 T-cells and were immunized with MOG_35–55/CFA on day 0. At days 5, 7 and 10 post-immunization, cervical and inguinal lymph nodes and spleens were harvested and CFSE dilution of CD45.2+ TCR β + CD8− CD4+ T-cells measured. Representative histograms of 2D2 CD4 T-cells CFSE dilution at day 10 in control CD8 T-cell recipient mice (top panel) and MOG-specific CD8 T-cells (bottom panel) are shown. Numbers on the histograms indicate the percentage of gated cells that were either in the CFSE-lowest or CFSE-high fractions in the OVA-CD8 and MOG-CD8 recipients.

(C) The graph indicates % suppression, calculated as % suppression = 100% − ((test condition/control condition)*100). Data are representative of three independent experiments. Cumulative graphs from days 5, 7, and 10 are shown.

(D) Mice were immunized with MOG_35–55/CFA, followed by transfer of MOG-specific (or control) CD8 T-cells at day 12 post-immunization. Data are representative of two independent (n=20 per condition).

(E) MOG- (or OVA-) CD8 T-cells were transferred into naïve mice. The next day, adoptive EAE was induced using purified activated CD4 from MOG_35–55-immunized mice. Data are representative of 5 experimental replicates (n=25 per condition).