Figure 1.

B- and T-cell responses in pigs immunized with a single dose and different amounts of B₂T. Time course of the specific antibody responses in sera collected on the indicated days pi. (A) Total anti peptide B IgG titers analyzed by ELISA. Each point depicts mean antibody titers (calculated as described in Methods) ± SD for each group of pigs (n = 5). (B) Virus neutralization titers, VNT, expressed as the reciprocal log10 of the last serum dilution that neutralized 100 TCID50 of FMDV isolate O/UKG 11/01. Each symbol represents the value for an individual pig (numbering is included). Horizontal lines indicate the geometric mean for each animal group. In no case individual spontaneous reactivity was observed in the titers determined at day 0. Dotted lines denotes the assay detection limit. In (A,B) arrows point FMDV challenge (day 25 pi). (C) Specific T-cell responses measured by an ex vivo IFN-γ ELISPOT at days 15 pi. The frequency of FMDV-specific IFN-γ secreting cells was determined as detailed in Methods. Horizontal bars represent the mean frequencies of IFN-γ release spots of triplicates of peripheral blood mononuclear cells (PBMCs) from pigs stimulated in vitro with B₂T (circles) or T (T3A) (squares) peptides (pig numbering is included).