Nasal immunisation induces rTgUPase-specific IgG responses in sera. Titres of both specific total IgG and IgG isotype antibodies in the sera of BALB/c mice were determined by ELISAs with rTgUPase as the bound target two weeks after the last immunisation. (A) Specific total IgG and (B) IgG1 and IgG2a titres in the sera of the mice vaccinated with rTgUPase. The results are expressed as the means of the OD₄₉₂ ± SD (n = 8) and are representative of three experiments. **p < 0.01 (vaccinated vs. PBS group).