Increased susceptibility to developing EAE in HVEM –/ – mice. Development of EAE was induced in WT mice and HVEM –/ – mice as described in Methods. (A) Mice were observed daily and scored. The mean clinical score plotted against time is shown. Five mice per group were tested. (B–D) Stronger MOG-specific T cell responses are detected in HVEM –/ – mice. The mice were immunized s.c. with 100 μg of MOG 35–55 emulsified in CFA (without toxin). Ten days later, DLN cells from the mice were isolated and cultured with various concentrations of MOG 35–55 peptide in complete RPMI-1640 medium for 5 days for proliferation analysis (B). Stronger responses were detected in the cells from the HVEM –/ – group at concentrations of 1, 5, and 25 μg (P < 0.05). The number of IFN-producing cells was determined by ELISPOT (C). Cells producing higher levels of IFN were detected in HVEM –/ – mice (P < 0.001). DLN cells were stimulated with antigens overnight for ELISPOT to determine the frequency of antigen-specific T cells (D). DLN cells from HVEM –/ – mice contained a higher frequency of IFN-producing cells (P < 0.001). One of 3 experiments is presented.