Figure 4.

Immune responses to Theiler's murine encephalomyelitis virus (TMEV) during the chronic stage of infection. Induced regulatory T cell (iTreg)‐late (hatched bars) and control mice (closed bars) had similar anti‐TMEV lymphoproliferative (A) and antibody responses to TMEV (B). A. Mononuclear cells were isolated from spleens of iTreg‐late mice or control mice during the chronic stage and stimulated with TMEV at a multiplicity of infection (MOI) of 5, 1, 0.1 or by irradiated TMEV‐infected spleen cells that were incubated with TMEV overnight to act as antigen presenting cells (APCs). Lymphoproliferation was quantified by a [³ H]thymidine incorporation assay. The two groups of mice had similar levels of TMEV‐specific lymphoproliferation (at 1 MOI, P = 0.40). Stimulation index = [counts per minute (cpm) of treatment group]/(cpm of no treatment group). Results are mean + standard error of the mean (SEM) from three pools of spleens from two mice per pool. B. The levels of total immunoglobulin (Ig)G (heavy and light chains) against TMEV in sera were titrated by enzyme‐linked immunosorbent assays. The two groups of mice had similar anti‐TMEV antibody responses (P = 0.83). Values are mean absorbance (Abs) + SEM of six sera per group.