Figure 2. Systemic administration of Y-MSPc suppresses “classical” EAE induced by a single encephalitogenic antigen/peptide more effectively than peptide administration.

(A, B), Suppression of actively induced EAE by Y-MSPc vs. specific antigen/peptide. BSF1 mice were immunized for induction of EAE by rhMOG (A) or PLP139-151 (B). On days indicated by arrows, the mice (n = 5 per group) received i.v. injection of soluble rhMOG (75 µg), PLP139-151 (75 µg), or Y-MSPc (75 µg) in 0.5 ml PBS, or PBS alone. Ψ, denotes mortality in the PLP139-151 treated group (Fig. 2B) due to anaphylactic shock on days 9 and 11 after immunization (one mouse and two mice, after the third and fourth injections, respectively), and therefore from day 11, the data are given for the two remaining mice only. (C, D), Suppression of passive EAE by Y-MSPc vs. specific peptide. EAE was passively transferred in naïve BSF1 mice with phMOG34-56-specific (C) or phPLP139-151-specific (D) line T cells (2×10⁶ cells). From days 1 to 5 (arrows), the mice (n = 6 per group) were injected i.v. with 75 µg of hMOG34-56, PLP-139-151, Y-MSPc, or KLH in 0.5 µl PBS, or with PBS alone. Shown are the clinical scores of one experiment out of two independent experiments that were performed of suppression of active (A, B) and passive (C, D) EAE. The two independent experiments yielded similar results, and the propensity of PLP peptide to induce high frequency of fatal anaphylactic shock was observed in the two experiments, as previously reported [52]. *, p<0.05; ** , p<0.005; ***, p<0.0005, compared to PBS control group; two tailed unpaired Student's t-test.