PMC

Interleukin-2 (IL-2) release of T-cell hybridoma 53/4 (a) or T-cell hybridoma 19 (b) after 40 hr culture with indicated amounts of guinea-pig myelin basic protein (gpMBP) (a) or casein (b): LEW rat thymocytes (square), L929 untransduced (circle), L929 RT1.B^l-transduced (triangle), L929 RT1.D^l-transduced (inverted triangle).

Antigen-specificity of the FischOVA and the FischMBP lines: the FischMBP (a) and the FischOVA (b) lines were tested in proliferation assays with guinea-pig myelin basic protein (MBP) or ovalbumin (OVA). (c) The FischMBP line was tested using a panel of overlapping rat MBP peptides, and to the following MBP molecules: guinea-pig MBP (MBP), rat MBP (RBP), bovine MBP (BBP) or human MBP (HBP). Two days after incubation, cells were pulsed with [H³]thymidine. The results represent the average counts per minute (c.p.m.) of triplicate or quadruplicate wells with standard error bars. Statistics for (c): analysis of variance + Tukey–Kramer P < 0·01 for peptides 71–90, 81–100, MBP, RBP, BBP and HBP, versus all other peptides or medium. Peptides 91–110 and 101–120 not different from peptide 81–100. The experiments were repeated at least twice with similar results.

Addition of TG2 has a developmental stage-dependent effect on OPC maturation. Exogenous guinea pig TG2 (gpTG2) was added to different developmental stages of the oligodendrocyte (OLG) lineage. Schematic representation of the experimental set up is shown in A. gpTG2 was added once to oligodendrocyte progenitor cells (OPCs) and analyzed at the immature OLG (imOLG, “I,” B, n = 5) and mature OLG stage (mOLG, “II,” C,D, n = 5), added both at the OPC stage and the imOLG stage and analyzed at the mOLG stage (“III,” E,F, n = 8), or added at the imOLGs and analyzed at the mOLG stage (“IV,” G,H, n = 5). OPC differentiation (B,C,E,G) and myelin membrane formation (D,F,H) are, respectively, assessed as the percentage of myelin basic protein (MBP)-positive cells and the percentage of myelin membrane bearing MBP-positive cells. Data are shown as mean + SEM, calculated as average percentage compared to vehicle-treated (CTRL), which was set to 100% in each independent experiment. The percentage of MBP-positive cells in vehicle-treated cells is 6.3 ± 1.6% at the imOLG stage (B) and 20.8 ± 11.3% at the mOLG stage (C,E,G), the percentage of myelin membranes at the mOLG stage is 40.8 ± 24.4% (D,F,H). Statistical analyses were performed using a one-sample t-test (^*p < 0.05).

Increased antigen concentration augments the antigen presentation capacity of infected antigen-presenting cells (APCs). Peritoneal exudate cells (PECs) were infected with vaccinia virus (VACV) [multiplicity of infection (MOI) = 2] for 4 hr and then pulsed with a titration of guinea pig myelin basic protein (GPMBP; 50–250 nm) before being co-cultured with antigen-specific T cells. Supernatants (50 μl) were collected at 24 to 48 hours post infection (hpi) and assayed for interleukin (IL)-2 using the CTLL IL-2 bioassay.