Figure 3.

Proliferative responses of lymph node cells of rats immunized with myelin oligodendrocyte glycoprotein (MOG) (a–c) and MOG-P7 (d–f). Lymph node cells (2 × 10⁵ cells/well) were cultured in triplicate with MOG (10, 33 and 100 μg/ml), myelin basic protein (MBP; 10, 33 and 100 μg/ml) or MOG-P1–8 (100 μg/ml) for 3 days, with the last 18 hr in the presence of 0·5 μCi [³H]thymidine. On day 14 postimmunization (p.i.) of MOG immunization, T cells showed modest but significant responses to MOG protein, whereas the responses to MBP and MOG peptides were marginal (stimulation index < 2) (a). On day 21 p.i., T cells responded vigorously to MOG protein and significantly to MOG P1, P2, P5 P6 and P7 (stimulation index > 3) (b). On day 28 p.i., T cells responded only to MOG protein and P7 (c). Immunization with MOG P7 induced vigorous T-cell responses to MOG protein and MOG P7 on days 14 (d) and 21 p.i. (e) but such responses were not present on day 28 p.i. (f).